REVIEW | doi:10.20944/preprints202008.0359.v1
Subject: Biology, Plant Sciences Keywords: Abiotic stress; Melatonin; Water stress; Drought; Waterlogging; Antioxidants; Stress signalling, phytohormones
Online: 17 August 2020 (10:19:52 CEST)
Water stress (drought and waterlogging) is drastic abiotic stress to plant growth and development. Melatonin, bioactive plant hormone, has been widely tested in drought situations in diverse plant species, while a few studies on the role of melatonin in waterlogging stress conditions have been published. In the current review, we analyze the bio-stimulatory functions of melatonin on plants under both drought and waterlogging stress. Melatonin controls the levels of reactive oxygen and nitrogen species and positively changes the molecular defense to improve plant tolerance against drought and waterlogging stress. Moreover, the crosstalk of melatonin and other phytohormones is a key element on plant survival under drought stress, while this relationship needs further investigation under waterlogging stress. In this review, we draw the complete story of water stress on both sides: drought and waterlogging through discussing the previous critical studies under both conditions. Moreover, we suggest several research directions, especially for waterlogging, which remains a big vague piece of melatonin and water stress puzzle.
Subject: Biology, Plant Sciences Keywords: drought stress; osmotic stress; rice; transcription factors; stress signaling; qtl; breeding
Online: 24 December 2019 (11:39:50 CET)
Many studies were done in the development of drought stress-tolerant transgenic plants, including crop plants. Rice is considered to be a vital crop target for improving drought stress tolerance. Much transgenic rice showed improved drought stress tolerance was reported to date. They are genetically engineered plants that are developed by using genes that encode proteins involved in drought stress regulatory networks. These proteins include protein kinases, transcription factors, enzymes related to osmoprotectant or plant hormone synthesis, receptor-like kinase. Of the drought stress-tolerant transgenic rice plants described in this review, most of them display retarded plant growth. In crop crops, plant health is a fundamental agronomic trait that can directly affect yield. By understanding the regulatory mechanisms of retarded plant growth under drought stress, conditions are necessary precursors to developing genetically modified plants that result in high yields.
ARTICLE | doi:10.20944/preprints201801.0280.v1
Subject: Biology, Plant Sciences Keywords: cold stress; heat stress; stress recovery; mitochondria; proteomics; respiration; Brassica; angiosperms
Online: 30 January 2018 (10:31:07 CET)
Complex proteomic and physiological approaches to study cold and heat stress responses in plant mitochondria are still limited. Variations in the mitochondrial proteome of cauliflower (Brassica oleracea var. botrytis) curds after cold and heat and after stress recovery were assayed by 2D PAGE in relation to respiratory parameters. Quantitative analysis of the mitochondrial proteome revealed numerous stress-affected protein spots. In cold alternative oxidase isoforms were extensively upregulated; major downregulations in the level of photorespiratory enzymes, porine isoforms, oxidative phosphorylation (OXPHOS) and some low-abundant proteins were observed. On the contrary, distinct proteins, including carbohydrate metabolism enzymes, heat-shock proteins, translation, protein import, and OXPHOS components were involved in heat response and recovery. Few metabolic regulations were suggested. Cauliflower plants appeared less susceptible to heat; closed stomata in heat stress resulted in moderate photosynthetic, but only minor respiratory impairments, however photosystem II performance was unaffected. Decreased photorespiration corresponded with proteomic alterations in cold. Our results show that cold and heat stress not only operate in diverse mode (exemplified by cold-specific accumulation of some heat shock proteins), but exert some associations on molecular and physiological levels. This implies more complex model of action of investigated stresses on plant mitochondria.
REVIEW | doi:10.20944/preprints202101.0384.v1
Subject: Medicine & Pharmacology, Allergology Keywords: flavonoids; cellular stress response; neurodegenerative disorders; ER stress proteotoxicity; oxidative stress; neuroinflammation
Online: 19 January 2021 (14:02:03 CET)
Neurodegenerative disorders such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyloidal lateral sclerosis (ALS), and Huntington disease (HD) are the most concerned disorders due to the lack of effective therapeutics and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, yet they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and ER-stress, which combats with stress conditions, but the overwhelming cellular stress response induces cell damage. Small molecules such as flavonoids could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the mechanistic ways of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.
ARTICLE | doi:10.20944/preprints202104.0116.v2
Online: 6 April 2021 (14:57:54 CEST)
While sex ratios at birth (SRB) have been shown to vary within and across populations, after over a century of research, explanations have remained elusive. A variety of ecological, demographic, economic, and social variables have been evaluated, yet their association with SRB has been equivocal. Here, in an attempt to shed light on this unresolved topic within the literature, we approach the question of what drives variation in SRB using detailed longitudinal data spanning the frontier-era to the early 20th century in a US population. Using several measures of environmental harshness, we find that fewer boys are born during challenging times. However, these results hold only for the frontier-era and not into a period of rapid industrialization. We argue that the mixed state of the literature may result from the impact and frequency of exogenous stressors being dampened in post-industrial societies.
ARTICLE | doi:10.20944/preprints202101.0406.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Adapted COVID-Stress Scales; Stress in Academic Professionals; Resilience to COVID stress in Academia
Online: 20 January 2021 (16:37:25 CET)
To mitigate the COVID-19 infection, many world governments endorsed the cessation of non-essential activities, such as the school attendance. Thereby, forcing the evolution of the teaching model to the virtual classroom. In the present work we show the application of a modified version of the adapted COVID-19 stress scales (ACSS) which also included teaching anxiety and preparedness, and resilience for academic professionals in Mexico, during the unprecedented transformation of the education system undergone in the COVID-19 quarantine. Most of the studied variables: gender, age, academic degree, household occupants, having a disease, teaching level, teaching mode, work hours, resilience, teaching anxiety and preparedness, and fear of being an asymptomatic patient (FOBAP), showed significant statistical correlation between each other (p<0.050) and to the 6 areas of the ACSS (danger, contamination, social economical, xenophobia, traumatic stress and compulsive checking). Our results further showed that the perceived stress and anxiety, fell into the category of absent to mild with only the danger section of the ACSS falling into the moderate category. Finally, resilience generated throughout the quarantine, seems to be a predictor of the adaptation the academic professional has undergone to cope with stress.
REVIEW | doi:10.20944/preprints201812.0145.v1
Subject: Life Sciences, Biochemistry Keywords: drought stress; drought models; drought tolerance; oxidative stress; phytohormones; polyethylene glycol (PEG); stress markers
Online: 12 December 2018 (12:19:35 CET)
Drought is one of the major stress factors affecting growth and development of plants. In this context, drought-related losses of crop plant productivity impede sustainable agriculture all over the world. In general, plants responses to water deficit by multiple physiological and metabolic adaptations at the molecular, cellular and organism levels. To understand the underlying mechanisms of drought tolerance, adequate stress models and arrays of reliable stress markers are required. Therefore, in this review we comprehensively address currently available models of drought stress, based on culturing plants in soil, hydroponic or agar culture. These experimental setups give access to different aspects of plant response to drought, like decrease of tissue water potential, reduction of stomata conductance and photosynthesis efficiency, accumulation of low-molecular weight solutes (metabolic adjustment) and drought protective proteins. Till now, this pattern of markers was successfully extended to the methods of enzyme chemistry, molecular biology and omics techniques. Thus, conventional tests can be efficiently complemented by determination of phytohormone and reactive oxygen species (ROS) contents, activities of antioxidant enzymes, as well as comprehensive profiling of transcriptome, proteome and metabolome.
ARTICLE | doi:10.20944/preprints202212.0211.v1
Subject: Life Sciences, Molecular Biology Keywords: klotho; estrogen; hippocampus; chronic stress; sex difference; stress resilience
Online: 13 December 2022 (01:09:36 CET)
Klotho (KL) is a glycosyl hydrolase and aging-suppressor gene. Stress is a risk factor for depression and anxiety that are highly comorbid with each other. The aim of this study was to determine KL is regulated by estrogen and plays an important role in sex differences in stress resilience. Our results showed that KL was regulated by estrogen in rat hippocampal neurons in vivo and in vitro and was essential for estrogen-mediated increase in the number of presynaptic vesicular glutamate transporter 1 (Vglut1) positive clusters on the dendrites of hippocampal neurons. The role of KL in sex differences in stress responses was examined in rats using three-week chronic unpredictable mild stress (CUMS). CUMS produced a deficit in spatial learning and memory, anhedonic-like and anxiety-like behaviors in male but not female rats, which was accompanied by a reduction in KL protein levels in the hippocampus of male, but not female rats. This demonstrated the resilience of female rats to CUMS. Interestingly, knockdown of KL protein levels in the rat hippocampus of both sexes caused a decrease in stress resilience in both sexes, especially in female rats. These results suggest that regulation of KL by estrogen plays an important role in estrogen-mediated synapse formation, and KL plays a critical role in the sex differences in cognitive deficit, anhedonic-like and anxiety-like behaviors induced by chronic stress in rats, highlighting an important role of KL in sex differences in stress resilience.
ARTICLE | doi:10.20944/preprints202105.0180.v1
Subject: Medicine & Pharmacology, Allergology Keywords: oxidative stress; nitrosative stress; immune response; inflammation; antioxidants; LPS
Online: 10 May 2021 (11:43:52 CEST)
An immune-inflammatory response is accompanied by increased nitro-oxidative stress. The aims of this mechanistic review are to review: a) the role of redox sensitive transcription factors and enzymes, ROS/RNS production and the activity of cellular antioxidants on the activation and performance of macrophages, dendritic cells, neutrophils, T cells, B cells and natural killer cells; b) the involvement of high-density lipoprotein (HDL), apolipoprotein (Apo)A1, paraoxonase (PON)-1, and oxidized phospholipids in the regulation of the immune response; and c) the detrimental effects of hypernitrosylation and chronic nitro-oxidative stress on the immune response. The redox changes during immune-inflammatory responses are orchestrated by the actions of nuclear factor (NF)-κB, HIF1alpha, the mechanistic target of rapamycin (mTor), the phosphatidylinositol 3‑kinase (PI3K) / protein kinase B (AKT) signalling pathway, mitogen-activated protein (MAP) kinases, 5' AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor (PPAR). The performance and survival of individual immune cells is under redox control and sensitive to intracellular and extracellular levels of ROS/RNS and is heavily influenced by cellular anti-oxidants including the glutathione and thioredoxin systems, nuclear factor erythroid 2-related factor 2 (Nrf-2), and the HDL complex. Chronic nitro-oxidative stress and hypernitrosylation inhibit the activity of those antioxidant systems, the tricarboxylic acid cycle, mitochondrial functions, and the metabolism of immune cells. In conclusion, those redox-associated mechanisms modulate metabolic reprogramming of immune cells, macrophage and T helper cell polarization, phagocytosis, production of pro- versus anti-inflammatory cytokines, immune training and tolerance, chemotaxis, pathogen sensing, antiviral and antibacterial effects, Toll-like receptor activity, and endotoxin tolerance.
ARTICLE | doi:10.20944/preprints202006.0283.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Metabolic Syndrome; Obesity; inflammation; Oxidative Stress; nitrosative stress; biomarkers
Online: 23 June 2020 (11:35:38 CEST)
Purpose: To investigate the alterations in nitro-oxidative stress (OS) and antioxidant status in adolescents with metabolic syndrome (MetS) and whether these alterations occur independently from effects of overweight or obesity.Methods: Blood was collected in 47 adolescents with MetS and 94 adolescents without MetS as assessed with the International Diabetes Federation criteria. The International Obesity Task Force (IOTF) criteria were used to classify the subjects into those with overweight or obesity. We measured nitro-oxidative biomarkers including nitric oxide metabolites (NOx), lipid hydroperoxides (LOOH), and malondialdehyde (MDA), and antioxidant biomarkers, i.e. total radical-trapping antioxidant parameter (TRAP), paraoxonase (PON)-1 activity, thiol (SH-) groups, as well as tumor necrosis factor-α, glucose, insulin, triglycerides, uric acid and high-density lipoprotein cholesterol (HDL-C).Results: Logistic regression analysis showed that increased MDA and NOx and a lowered TRAP/uric acid ratio were associated with MetS. Machine learning including soft independent modeling of class analogy (SIMCA) showed that the top-3 most important features of MetS were increased glucose and MDA and lowered HDL-C. Support vector machine using MDA, glucose, insulin, HDL-C, triglycerides and body mass index as input variables yielded a 10-fold cross-validated accuracy of 89.8% when discriminating MetS from controls. The association between MetS and increased MDA was independent from the effects of overweight-obesity. glucose, insulin, triglycerides and HDL-C.Conclusion: In adolescents, increased MDA formation is a key component of MetS, indicating that increased production of reactive oxygen species with consequent lipid peroxidation and aldehyde formation participate in the development of MetS.
REVIEW | doi:10.20944/preprints202006.0016.v1
Subject: Life Sciences, Genetics Keywords: abiotic stress; biotic stress; biofortification; breeding; French bean; QTLs
Online: 3 June 2020 (09:43:01 CEST)
French bean (Phaseolus vulgaris L.) a member of family Leguminosae is a useful source of protein (∼22%), minerals (folate), vitamins and fibre. Abiotic and biotic stresses are the constraints to high yield and production of French bean. Varieties reluctant to diseases as well as abiotic stresses is among the top breeding objectives for the French bean. Mendelian ratios could know the genetically reliable forms of resistance, whereas it's more robust to understand the intricate kinds, often referred to as quantitative trait loci (QTL). Here, we review and compile the information from the studies related to the identification of QTLs for critical biofortification traits, biotic and abiotic stresses in French bean. Successful map-based cloning requires QTLs represent single genes which could be isolated in near-isogenic lines, and also the genotypes could be unambiguously inferred by progeny testing. Overall, this information will be useful for directing the French bean breeders to select a suitable method for the inheritance evaluation of quantitative traits and determining the novel genes in germplasm resources to ensure that much more potential of genetic information may be uncovered.
ARTICLE | doi:10.20944/preprints201911.0358.v1
Subject: Biology, Plant Sciences Keywords: abiotic stress; oxidative stress; salinity; nutrient deficiency; osmolytes; methylglyoxal
Online: 28 November 2019 (09:49:35 CET)
This study was undertaken to elucidate the role of trehalose (Tre) in mitigating oxidative stress under salinity and low P in maize. Eight-day-old maize seedlings of two maize varieties, BARI Hybrid Maize-7 and BARI Hybrid Maize-9 were subjected to salinity (150 mM NaCl), low P (5 µM KH2PO4) and their combined stress with or without 10 mM Tre for 15-d.Salinity and combined stress significantly inhibited the shoot length, root length, and root volume, whereas, low P increased the root length and volume in both genotypes. Exogenous Tre in the stress treatments increased all of the growth parameters as well as decreased the salinity, low P and combined stress-mediated Na+/K+, ROS, MDA, LOX activity and MG in both genotypes. Under salinity and low P stress, the SOD activity increased in both genotypes, but the activity decreased in combined stress. POD activity increased in all stress treatments. Interestingly, Tre application enhanced the SOD activity in all the stress treatments but inhibited the POD activity. Both CAT and GPX activity were increased by saline and low P stress while the activities inhibited in combined stress. Similar results were found for APX, GR, and DHAR activities in both genotypes. However, MDHAR activity was inhibited in all the stresses. Interestingly, Tre enhanced CAT APX, GPX, GR, MDHAR and DHAR activities suggesting the amelioration of ROS scavenging in maize under all the stresses. Increased GST activity in presence or absence of Tre might involve in detoxification of hydroperoxides as well as leaf senescence. On the other hand, increased glyoxalase activities in saline and low P stress in BHM-9 suggested better MG detoxification system because of down-regulation of Gly-I activity in BHM-7 in those stresses. Tre also increased the glyoxalase activities in both genotypes under all the stresses. Tre improved the growth in maize seedlings by decreasing Na+/K+, ROS, MDA, and MG through regulating antioxidant and glyoxalase systems.
ARTICLE | doi:10.20944/preprints201901.0108.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: schizophrenia, inflammation, nitrosative stress, tryptophan catabolites, cytokines, oxidative stress
Online: 11 January 2019 (10:37:50 CET)
BACKGROUND: Stable-phase schizophrenia may comprise two distinct nosological entities namely Major Neuro-Cognitive Psychosis (MNP, largely overlapping with the deficit syndrome) and simple NP (SNP), which are defined by neuroimmune and neurocognitive abnormalities. Furthermore, cognitive impairments and PHEM (psychotic, hostility, excitation, mannerism) and negative symptoms load on the same dimension.METHODS: The current study aimed to investigate associations of psychomotor retardation (PMR) and clinical as well as biomarker characteristics of schizophrenia. We recruited 40 healthy controls and 79 schizophrenia patients and measured IgA responses to tryptophan catabolites (TRYCATs), IgM to malondialdehyde and nitroso (NO)-cysteinyl, macrophage inflammatory protein-1 (MIP-1), soluble interleukin (IL)-1 receptor antagonist (sIL-1RA), IL-10, CCL-11 as well as PMR items of different rating scales and motor screening task (MOT). RESULTS: PMR differentiated schizophrenia from controls and MNP from SNP. In addition, PMR was strongly associated with executive functions, deficits in episodic and semantic memory, PHEM and negative (PHEMN) symptoms. Around 50% of the variance in PMR was predicted by the cumulative effects of immune activation, CCL-11, TRYCATs and NO-Cysteinyl levels, and lowered natural IgM. PRM may be reliably combined with PHEMN symptoms and memory and executive impairments into one latent vector reflecting overall psychopathology.CONCLUSIONS: Current findings indicate that PMR may be a key psychopathological feature of schizophrenia and mainly MNP. In addition, PMR and associated impairments in memory and executive functions, and PHEMN symptoms may be driven by deficits in the compensatory immune regulatory system (natural IgM) combined with increased production of neurotoxic immune products, namely TRYCATs and IgM to NO-cysteinyl, and an endogenous cognition deteriorating chemokine, namely CCL-11.
ARTICLE | doi:10.20944/preprints202102.0474.v1
Online: 22 February 2021 (13:26:18 CET)
Transposable elements (TE) function as one of the major effectors to respond to biological or environmental stress. The mobility of TEs, which is heavily controlled under normal conditions, may be activated by stress. LncRNAs are emerging as a crucial tool in the regulation of TEs. This study focuses on the gene expression of THAP9, a domesticated transposon and lncRNA THAP9-AS1 (THAP9-antisense1), which form a sense and antisense gene pair with a promoter overlap of approximately 350bp. Under basal conditions, THAP9 is preferentially transcribed while THAP9-AS1 is heavily down-regulated. In the S-phase of the cell cycle, THAP9 expression exhibits stress-specific effects ranging from moderate enhancement to no change. On the other hand, THAP9-AS1, which has previously been reported to be upregulated in several cancers, always demonstrates enhanced expression under stress. Moreover, THAP9-AS1 is transcriptionally favoured during stress since the stress-induced fold-increase of THAP-AS1 expression is always higher than THAP9. Interestingly, the expression of both THAP9 and THAP9-AS1 exhibit a striking periodicity throughout the S-phase, reminiscent of cell cycle regulated genes. Thus, this study sets the stage to further explore the relationship between THAP9 and THAP9-AS1 and investigate THAP9-AS1’s potential regulatory role during stress.
ARTICLE | doi:10.20944/preprints202007.0434.v1
Online: 19 July 2020 (20:24:54 CEST)
This article shows the alternative learning methodology to stimulate the holistic side of students’ minds to achieve the increment of the innovation skill, managing the creative competencies and level of stress. The present research study is pre-experimental research designed with prior and posterior measurement, longitudinal, explanatory, and co-relational, with the main objective to demonstrate the effect of the holistic innovation coefficient of the beneficiaries of the program “Impulsa Peru”. Program Results: It has been concluded that the experimental group is significant over the control group. Therefore, the holistic innovation methodology had an impact on the experimental group. Conclusions: Hypothesis 1 is fulfilled in which it is affirmed that the holistic innovation methodology has a positive impact on the level of coefficient of holistic innovation of the student mentors of the women recyclers of the program Impulsa Peru with a significance level of 0.05%.
ARTICLE | doi:10.20944/preprints202102.0361.v1
Subject: Life Sciences, Biochemistry Keywords: Transgenic rice; metacaspase; ER stress; salinity stress; programmed cell death
Online: 17 February 2021 (10:04:38 CET)
Endoplasmic reticulum (ER) is an important organelle responsible as protein synthesis regulator in plant. High salinity can also lead to the activation of ER stress, caused by the accumulation of misfolded protein. This could lead to a stress response mechanism, unfolded protein response (UPR). Failure of UPR to reverse the effect of protein misfolding will activate Programmed Cell Death (PCD). Metacaspase genes regulate programmed cell death (PCD) in plants. The present study was focused on comprehensive gene analyses of the expression patterns of type II rice metacaspase (OsMC) genes in response to the endoplasmic reticulum (ER) and salinity stress in rice leaf and OsMC4 in callus. A strong evidence of unfolded protein response (UPR) during tolerance to both ER and salinity stress was found in the present study. Overexpression of OsMC4 in rice callus as a fusion protein with TagRFP and controlled by the CaMV35 promoter caused major changes in the expression of the stress ER-marker genes, protein disulfide isomerase (PDI) and Binding immunoglobulin Protein (BiP), and OsMC4 in overexpressing calli. These expression analyses of the OsMC family provide valuable information for further functional studies on the biological roles of OsMCs in PCD related to ER and salinity stress responses.
ARTICLE | doi:10.20944/preprints201808.0059.v1
Subject: Life Sciences, Other Keywords: chagas disease; cardiomyopathy; mitochondrial stress; endoplasmic reticulum stress; 2-aminopurine
Online: 3 August 2018 (04:36:58 CEST)
Trypanosoma cruzi infection results in debilitating cardiomyopathy, which is a major cause of mortality and morbidity in the endemic regions of Chagas disease (CD). The pathogenesis of Chagasic cardiomyopathy (CCM) has been intensely studied as a chronic inflammatory disease until recent observations reporting the role of cardio-metabolic dysfunctions. In particular, we demonstrated accumulation of lipid droplets and impaired cardiac lipid metabolism in the hearts of cardiomyopathic mice and patients, and their association with impaired mitochondrial functions and endoplasmic reticulum (ER) stress in CD mice. In the present study, we examined whether treating infected mice with an ER stress inhibitor can modify the pathogenesis of cardiomyopathy during chronic stages of infection. T. cruzi infected mice were treated with an ER stress inhibitor 2-Aminopurine (2AP) during the indeterminate stage and evaluated for cardiac pathophysiology during the subsequent chronic stage. Our study demonstrates that inhibition of ER stress improves cardiac pathology caused by T. cruzi infection by reducing ER stress and downstream signaling of phosphorylated eukaryotic initiation factor (P-elF2α) in the hearts of chronically infected mice. Importantly, cardiac ultrasound imaging showed amelioration of ventricular enlargement, suggesting that inhibition of ER stress may be a valuable strategy to combat the progression of cardiomyopathy in Chagas patients.
REVIEW | doi:10.20944/preprints202103.0041.v1
Subject: Life Sciences, Biochemistry Keywords: PGPR; salt stress; salinity; abiotic stress; ACC deaminase; seed priming; IAA
Online: 1 March 2021 (18:27:16 CET)
To date, soil salinity becomes a huge obstacle for food production worldwide since salt stress in plants is one of the major factors limiting agricultural productivity. It is estimated that a significant loss of crops (20%–50%) would be due to drought and salinity. To embark upon this harsh situation, numerous strategies such as plant breeding, plant genetic engineering, and a large variety of agricultural practices including the applications of plant growth-promoting rhizobacteria (PGPR) and seed biopriming technique have been developed to improve plant defense system against salt stress, resulting in higher crop yields to meet human’s increasing food demand in the future. In the present review, we update and discuss the advantageous roles of beneficial PGPR as green bioinoculants in mitigating the burden of high saline conditions on morphological parameters and on physio-biochemical attributes of plant crops via diverse mechanisms. In addition, the applications of PGPR as a useful tool in seed biopriming technique are also updated and discussed since this approach exhibits promising potentials in improving seed vigor, rapid seed germination, and seedling growth uniformity, Furthermore, the controversial findings regarding the fluctuation of antioxidants and osmolytes in PGPR-treated plants are also pointed out and discussed.
ARTICLE | doi:10.20944/preprints202012.0362.v1
Subject: Biology, Anatomy & Morphology Keywords: combined stresses; drought stress; heat stress; maize; root morphology; root types
Online: 15 December 2020 (09:39:56 CET)
Plants are continually exposed to multiple stresses, which co-occur in nature and the net effects are frequently more non-additive (i.e., synergistic or antagonistic) suggesting ‘unique’ responses respect to that of the individual stress. Further, plant stress responses are not uniforms showing a high spatial and temporal variability among and along the different organs. In this respect, the present work investigated the morphological responses of different root types (seminal, seminal lateral, primary, primary lateral) of maize plants exposed to single (drought and heat) and combined stress (drought + heat). Data were evaluated by a specific root image analysis system (WinRHIZO) and analyzed by uni- and multi-variate statistical analysis. The results indicated that primary root and their laterals were the types more sensitive to the single and combined stresses while the seminal laterals specifically responded to the combined only. Further, antagonistic and synergistic effects were observed for the specific traits in the primary and their laterals and in the seminal lateral roots in response to the combined stress. These results suggested that maize root system modified specific root types and traits to face with different stressful environmental conditions highlighting that the adaptation strategy to the combined stress may be different from that of the individual ones. The knowledge of “unique or shared” responses of plant to multiple stress can be utilized to develop varieties with broad spectrum stress tolerance.
ARTICLE | doi:10.20944/preprints202011.0251.v1
Subject: Biology, Anatomy & Morphology Keywords: heat stress; temperature humidity index; laying performance; egg quality; stress indicators
Online: 6 November 2020 (16:58:30 CET)
The present study investigated the effect of different ambient temperature and relative humidity (RH) but equal temperature-humidity index (THI) on laying performance, egg quality, heterophil to lymphocyte ratio (H/L ratio), corticosterone (CORT) concentration in blood, yolk and albumen, and plasma biochemical parameters in laying hens. One hundred and twenty commercial hens (Hy-Line Brown) aged 60 weeks were allocated into 2 environmental chambers. Laying hens were subjected to either one of two thermal treatments, i.e., 26ºC and 70% RH (LH75) and 30ºC and 30% RH (HL75) for 28 days. Both thermal treatments had equal THI being 75. Neither LH75 nor HL75 affected (P > 0.05) laying performance including egg production, egg weight, egg mass, feed intake, and feed conversion ratio. Plasma biochemical parameters such as total cholesterol, high-density lipoprotein cholesterol, triglyceride, calcium, magnesium, and phosphorus was not altered (P > 0.05) by thermal treatments. As to the stress indicators, both environment regimes failed (P > 0.05) to affect blood H/L ratio and CORT levels in plasma, yolk and albumen although albumen CORT levels were elevated (P < 0.05) in LH75 vs. HL75 at days 3, 7, and 28. In conclusion, our study suggests that laying hens performed and responded equally when they were exposed to equal THI environment conditioned from either 26ºC and 70% RH or 30ºC and 30% RH. The results of this study will be served as a scientific basis for management decisions and handling under thermally challenging conditions.
ARTICLE | doi:10.20944/preprints202009.0619.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: COVID-19 Mexico; stress in healthcare professionals; COVID-19 stress scale
Online: 26 September 2020 (08:07:00 CEST)
The world is currently, subjected to the worst health crisis documented in modern history; an epidemic led by the novel coronavirus disease 2019 (COVID-19). At the epicenter of this crisis, healthcare professionals continue working to safeguard our well-being. To the regular high levels of stress, COVID new heights even more to healthcare professionals so depending on the area, specialty, and type of work. Here we investigated what are the tendencies, or areas most affected. Through an adaptation of the original COVID-stress scale, we developed a remote, fast test designed for healthcare professionals of the Northeastern part of Mexico, an important part of the country with economic and cultural ties to the US. Our results showed 4 key correlations as highly dependent: Work area – Xenophobia (p < 0.045), Work with COVID patients - Traumatic stress (p < 0.001) and Total number of COVID patients per day – Traumatic stress (p < 0.027), and Total number of COVID patients - Compulsive checking and reassurance. Overall concluding that normal levels of stress have increased (mild – moderate). Additionally, we further determine that the fear of being an asymptomatic patient (potential to spread without knowing) continues being a concern.
ARTICLE | doi:10.20944/preprints202001.0268.v1
Subject: Engineering, Mechanical Engineering Keywords: residual stress prediction; maraging steel 350; experimental measurement of residual stress
Online: 23 January 2020 (16:12:51 CET)
Rapid and accurate prediction of residual stress in metal additive manufacturing processes is of great importance to guarantee the quality of the fabricated part to be used in a mission-critical application in the aerospace and automotive industries. Experimentation and numerical modeling are valuable tools for measuring and predicting the residual stress; however, to-date conducting experimentation and numerical modeling is expensive and time-consuming. Thus, herein, a physics-based thermomechanical analytical model is proposed to predict the residual stress of the additively manufactured part rapidly and accurately. A moving point heat source approach is used to predict the temperature field by considering the effects of scan strategies, heat loss, and energy needed for solid-state phase transformation. Due to the high temperature gradient in this process, part experiences a high amount of thermal stress following solidification which may exceed the yield strength of the material. The thermal stress is obtained using Green’s function of stresses due to the point body load. The Johnson-Cook flow stress model is used to predict the yield surface of the part under repeated heating and cooling. As a result of the cyclic heating and cooling and the fact that the material is yielded, the residual stress build-up is predicted based on incremental plasticity and kinematic hardening behavior of the metal according to the property of volume invariance in plastic deformation in coupling with the equilibrium and compatibility conditions. The computational methodology is realized with the laser powder fusion of maraging steel 350 as a material of example. The validation of the predictive models has been presented in terms of the comparison of predicted and measured scan-direction and build-direction residual stress distributions along depth of build under various process parameter combinations. Moreover, for the first time, the Jonson-Cook parameters of maraging steel 350 are predicted using analytical modeling of machining forces and non-linear optimization techniques.
ARTICLE | doi:10.20944/preprints202001.0185.v1
Subject: Biology, Plant Sciences Keywords: Abiotic stress; Antioxidant defense; Glyoxalase; Ion homeostasis; Organic acid; Osmotic stress
Online: 17 January 2020 (10:02:34 CET)
Salinity is a serious environmental hazard which limits world agricultural production by adversely affects plant physiology and biochemistry. Hence increase tolerance against salt stress is very important. In this study, we explored the function of β-aminobutyric acid (BABA) in enhancing salt stress tolerance in rapeseed (Brassica napus L.). After pretreatment with BABA, seedlings were exposed to NaCl (100 mM and 150 mM) for 2 days. Salt stress increased Na content and decreased K content in shoot and root. It disrupted the antioxidant defense system by producing reactive oxygen species (ROS; H2O2 and O2•−), methylglyoxal (MG) content and causing oxidative stress. It also reduced the growth and photosynthetic pigments of seedlings but increased proline (Pro) content. However, BABA pretreatment in salt-stressed seedlings increased ascorbate (AsA) and glutathione (GSH) contents; GSH/GSSG ratio; and the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) as well as growth and photosynthetic pigments of plants. In addition, compared to salt stress alone BABA increased Pro content, reduced the H2O2, MDA and MG contents and decreased Na content in root and increased K content in shoot and root of rapeseed seedlings.
ARTICLE | doi:10.20944/preprints202001.0153.v1
Subject: Biology, Plant Sciences Keywords: antioxidant system; chilling stress; mineral homeostasis; nitric oxide; oxidative stress; rice
Online: 15 January 2020 (12:32:41 CET)
Being a chilling-sensitive staple crop, rice (Oryza sativa L.) is vulnerable to climate change. The competence of rice to withstand chilling stress should, therefore, be enhanced through technological tools. The present study employed chemical intervention like application of sodium nitroprusside (SNP) as nitric oxide (NO) donor and elucidated the underlying molecular mechanisms of NO-mediated chilling tolerance in rice. At germination stage, germination indicators were interrupted by chilling stress (5.0 ± 1.0°C for 8 h day‒1), while pretreatment with 100 μM SNP markedly improved the indicators. At seedling stage (14-day-old), chilling stress caused stunted growth with visible toxicity along with alteration of biochemical markers, for example, increase in oxidative stress markers (superoxide, hydrogen peroxide, and malondialdehyde) and osmolytes (total soluble sugar; proline and soluble protein content, SPC), and decrease in chlorophyll (Chl), relative water content (RWC), and antioxidants. However, NO application attenuated toxicity symptoms with improving growth performance which might be attributed to enhanced activities of antioxidants, mineral contents, Chl, RWC and SPC. Furthermore, principal component analysis indicated that water imbalance and increased oxidative damage were the main contributors to chilling injury, whereas NO-mediated mineral homeostasis and antioxidant defense were the critical determinants for chilling tolerance in rice. Collectively, our findings revealed that NO protects against chilling stress through valorizing cellular defense mechanisms, suggesting that exogenous application of NO could be a potential tool to evolve cold tolerance as well as climate resilience in rice.
ARTICLE | doi:10.20944/preprints201910.0307.v2
Subject: Life Sciences, Molecular Biology Keywords: antioxidant activity; cross-tolerance; glycine max; heat stress; proteomics; water stress
Online: 31 October 2019 (05:23:35 CET)
Water stress (WS) and heat stress (HS) have a negative effect on soybean plant growth and crop productivity. During WS, soybean plants opt for survival through ion homeostasis and the conformations of proteins are disconcerted as plant cells lose water while HS leads to difficulties in flowering and fruiting. Some of these changes include oxidative stress leading to the destruction of photosynthetic apparatus, macromolecules within cells and the onset of complex signaling cascades. Changes in the physiological characteristics, proteome, and certain metabolites investigated on molecular and cellular functions were studied in two soybean cultivars exposed to different heat and water stress conditions independently and in combination. Leaf protein composition was studied using 2-DE and complemented with MALDI TOF mass spectrometry. While two cultivars displayed genetic variation in response to water and heat stress, thirty-nine proteins were significantly altered in their relative abundance in response to WS, HS and combined WS+HS in both cultivars; a majority of them involved in metabolism, response to heat and photosynthesis showing significant cross-tolerance mechanisms. Functional analysis revealing a majority of heat responsive-proteins were more abundant during HS and combined stress (WS+HS) whereas these proteins were low to WS in cultivar PI 471938 and heat shock proteins were in low abundance to water, heat and combined stresses in cultivar R95-1705. Most protein abundances were not correlated with their expression at mRNA levels in PI cultivar, however, in cultivar R 95, the expression levels of transcript follow their relative abundance in proteins. Our systems bioinformatics analyses revealed that MED37C, a probable mediator of RNA polymerase transcription II protein showed potential interacting partners in Arabidopsis and our studies signifies the marked impact of this protein in PI cultivar. Elevated activities in antioxidant enzymes indicate that the PI-371938 cultivar has the ability to restore the oxidation levels and sustain the plant during the stress. Our study hypothesizes the plant’s development of cross-stress tolerance which will help foster the ongoing ventures in genetic modifications in stress tolerance.
ARTICLE | doi:10.20944/preprints201802.0061.v1
Subject: Medicine & Pharmacology, Other Keywords: Work-related stress; occupational stress; coping profile; garment workers; textile workers
Online: 7 February 2018 (10:26:49 CET)
Garment sector has crucial working field in Turkey.It has also very high risky occupational health conditions and safety.The objective of this study is to define level of job level, work-related stress’ symptoms, social support and coping mechanisms of garment workers and to determine any related factors.This study is descriptive and cross-sectional. The study population comprised garment workers in the 16-65 age range. The data was collected by Assessment Form, The Brief Stress Coping Profile and Brief Job Stress Questionnaire. The level of work-related stress was statistically higher among the workers who had chronic disease, low economic, education status and poor quality of sleep. Psychological and physical physiological reactions to stress were found higher among women workers and those with chronic disease.It also was seen that job stress scores had a meaningful relationship with “emotional expression involving others” (r =.20) and “Avoidance and suppression” coping profile (r =.16; p <.01).Psychological symptom scores were found to have a low level of meaningful relationship with “Seeking help for solution” (r =-.08), “changing point of view” (r=.13) and “emotional expression involving others” coping profiles (r=.21). Work-related stress causes many health and behavioral problems. Work related reasons and coping profiles have powerful effects on stress.
ARTICLE | doi:10.20944/preprints202212.0289.v1
Subject: Engineering, Mechanical Engineering Keywords: hypotrochoidal profile shafts; DIN3689 H-profiles; bending stress; rotating bending loads; flexure; torsional stress in profiled shafts; stress factor
Online: 16 December 2022 (02:40:22 CET)
Hypotrochoidal profile contours have been produced in industrial applications in recent years using twin-spindle processes, and they are considered effective high-quality solutions for positive shaft–hub connections. This study mainly concerns analytical approaches to determine the bending stresses in hypotrochoidal profile shafts. The formulation was developed according to bending principles using the mathematical theory of elasticity and conformal mappings. The loading was further used to investigate the rotating bending behaviour. The stress factors for the classical calculation of maximum bending stresses were also determined for all those profiles presented and compiled in the German standard DIN3689-1 for practical applications. The results were also compared with the corresponding numerical and experimental results, and very good agreement was observed. Additionally, based on previous work, the stress factor was determined for the case of torsional loading to calculate the maximum torsional stresses in the standardised profiles, and the results are listed in a table. This study contributes to the further refinement of the current DIN3689 standard.
ARTICLE | doi:10.20944/preprints202010.0249.v1
Online: 13 October 2020 (16:13:08 CEST)
Teaching is considered a multifarious task. Teachers, in the pursuit of educational success, are burdened with numerous teaching workloads and dilemmas causing them stress. This study endeavored to determine the influence of stress on professional satisfaction of multigrade teachers. It employed correlation research design involving thirty (30) purposively selected multigrade teachers in the Schools Division of General Santos City (GSC), Southern Philippines. Employing the survey method, tailored questionnaires were utilized to gather the needed data. The statistical tools employed in the analysis were weighted mean and Pearson Product Moment Correlation Coefficient. Moderate level of stress and high level of professional satisfaction are gained among the multigrade teachers surveyed. It was further found out that there is no significant relationship between stress and professional satisfaction, providing evidence that stress may not necessarily influence satisfaction. This result offers unique implications in theory, practice, and research which are discussed in the study.
ARTICLE | doi:10.20944/preprints201902.0147.v1
Online: 18 February 2019 (08:57:01 CET)
Human exposure to carbon nanotubes (CNTs) can cause health issues due to their chemical–physical features and biological interactions. These nanostructures cause oxidative stress, also due to endogenous ROS production, which increases following mitochondrial impairment. The aim of this in vitro study was to assess the health effects, due to mitochondrial dysfunction, caused by a sub-chronic exposure to a non-acutely toxic dose of multi walled CNTs (raw and functionalised). The A549 cells were exposed to MWCNTs (2 µg mL-1) for 36 days. Periodically, cellular dehydrogenases, pyruvate dehydrogenase kinase 1 (PDK1), cytochrome c release, permeability transition pore (mPTP) opening, transmembrane potential (Δψ m), apoptotic cells, and intracellular ROS were measured. The results, compared to untreated cells and to positive control formed by cells treated with MWCNTs (20 µg mL-1), highlighted the efficiency of homeostasis to counteract ROS overproduction, but a restitutio ad integrum of mitochondrial functionality was not observed. Despite the tendency to restore, the mitochondrial impairment persisted. Overall, the results underlined the tissue damage that can arise following sub-chronic exposure to MWCNTs.
REVIEW | doi:10.20944/preprints202207.0404.v1
Subject: Biology, Plant Sciences Keywords: Abiotic stress; biotic stress; biotechnology; climate change; CRISPR; crop improvement; genome editing
Online: 26 July 2022 (10:44:22 CEST)
Climate change poses a serious threat to global agricultural activity and food production. To address this issue, plant genome editing technologies have been developed to provide an alternative solution for crop improvement. Unlike conventional breeding techniques (e.g., selective breeding and mutation breeding), modern genome editing tools offer more targeted and specific alterations of the plant genome to produce crops with desired traits, such as higher yield and/or stronger resilience to the changing environment. In this review, we discuss the current development and future applications of genome editing technologies in mitigating the impacts of biotic and abiotic stresses on agriculture. We focus specifically on the CRISPR/Cas system, which has been the center of attention in the last few years as a revolutionary genome-editing tool in various species. We also conducted a bibliographic analysis on CRISPR-related papers published from 2012 to 2021 (10 years) to identify trends and possible gaps in the CRISPR/Cas-related plant research. In addition, this review article outlines the current shortcomings and challenges of employing genome editing technologies in agriculture with notes on future prospective. We believe combining conventional and more innovative technologies in agriculture would be the key to optimizing crop improvement beyond the limitations of traditional agricultural practices.
ARTICLE | doi:10.20944/preprints202111.0287.v1
Subject: Life Sciences, Microbiology Keywords: Excretory-secretory products; Angiostrongylus cantonensis; Astrocytes; Benzaldehydes; endoplasmic reticulum stress; oxidative stress
Online: 16 November 2021 (11:34:13 CET)
Excretory-secretory products (ESPs) are the main research targets for investigating the hosts and helminths interaction. Parasitic worms can migrate to parasitic sites and avoid the host immune response by secreting this product. Angiostrongylus cantonensisis an important food-borne zoonotic parasite that causes severe neuropathological damage and symptoms, including eosinophilic meningitis or meningoencephalitis in humans. Benzaldehydes are organic compounds composed of a benzene ring and formyl substituents. This compound has anti-inflammatory and antioxidation properties. Previous studies showed that 3-hydroxybenzaldehyde (3-HBA) and 4-hydroxybenzaldehyde (4-HBA) can reduce apoptosis in A. cantonensis ESPs treated astrocytes. These results on the protective effect underlying benzaldehyde have primarily focused on cell survival. The study was designed to investigate the molecular mechanisms of endoplasmic reticulum stress (ER stress) and oxidative stress in astrocytes in A. cantonensis ESPs treated astrocytes and to evaluate the therapeutic consequent of 3-HBA and 4-HBA. First, we initially established the RNA-seq dataset in each group, including Normal, ESPs, ESPs+3-HBA, and ESPs+4-HBA. We also found that benzaldehyde (3-HBA and 4-HBA) can stimulate astrocytes to express ER stress-related molecules after ESP treatment. The level of oxidative stress could also be decreased in astrocytes by elevating antioxidant activity and reducing ROS generation. These results suggested that benzaldehyde may be a potential therapeutic compound for human angiostrongyliasis to support brain cell survival by inducing the expression levels of ER stress- and oxidative stress-related pathway.
ARTICLE | doi:10.20944/preprints202110.0311.v1
Subject: Social Sciences, Education Studies Keywords: perceived stress; life satisfaction; academic performance; university students; stress management; COVID-19
Online: 21 October 2021 (13:59:07 CEST)
The circumstances arising from the exceptional situation caused by the COVID-19 pandemic have affected all socioeconomic areas in the last two years. The field of Education has not been an exception and the management of the situation seems to have caused an increase in the level of perceived stress of university students. On this basis, this research that aims, first, to analyze the student’s level of perceived stress during the de-escalation and return to normality period, secondly, to evaluate its relationship with life satisfaction and, finally, to detect the students' needs in stress management, has been developed. An exploratory-descriptive study of quantitative and cross-sectional nature has been carried out. 222 university students of the Childhood and Primary Education Degrees of the University of Jaén (Spain) have participated. The instruments, Perceived Stress Scale (PSS) and Satisfaction with Life Scale (SWLS) have been used. The results show a moderate and partial relationship among the dimensions of the used instruments. The obtained coefficients of determination are, Academic Performance (r² = .019) and Life Satisfaction (r² = .402), with a mean square error (SRMR) of .079. These findings show the need to develop actions within the university training program in effective stress management strategies.
REVIEW | doi:10.20944/preprints202109.0364.v1
Subject: Biology, Horticulture Keywords: stress tolerance; biological mechanisms; biotic/Abiotic stress; hybrid priming; high-quality seeds
Online: 21 September 2021 (14:02:07 CEST)
Farmers and seed companies constantly require high-quality seeds with excellent agronomic performance. However, faced with environmental adversity, limited natural resources and increasing food demand around the globe, more attention has turned to improving crop plant production by implementing efficient strategies. Seed priming technology has shown promising biological improvements leading to suitable agronomic performance in crop plants under adverse environmental conditions. Seeds are subjected to controlled conditions that are conducive to complex physiological, biochemical, and molecular changes, conferring specific stress tolerance to subsequent germination and growth conditions. In this review paper, we aimed to study the recent approaches in the efficiency of hydropriming, osmopriming, chemopriming, hormopriming, nanopriming, matrix priming, biopriming, physical priming and hybrid priming procedures in the production of crop plants under environmental adversity, as well as their biological mechanism changes. All priming methods demonstrated relevant changes in the biological mechanism related to crop plant production by mitigating salinity effects, heavy metals, and flooding stress and enhancing chilling, heat, drought and phytopathogen tolerance. We strongly recommend that researchers combine multiple priming methods, known as hybrid priming, in their investigations to provide novel technologies and additional biological approaches to enhance the knowledge of crop plant science. Thus, the findings shed light on the use of seed priming technology as a key strategy to increase crop plant production under environmental adversity by acquiring stress tolerance and enhancing agronomic traits to meet the global food demand.
Subject: Engineering, Mechanical Engineering Keywords: Laser shock peening; FE simulation; Residual stress; Minimum principal stress; Static damping
Online: 18 August 2021 (10:51:34 CEST)
Laser shock peening is a process which can reduce stress corrosion cracking and improve fatigue life by forming compressive residual stress on the surface of the material. In a computational FE simulation of laser shock peening, during applying the pressure load generated by the laser pulse to the surface of simulation geometry, the peening is simulated by explicit analysis and then convert to implicit analysis to dissipate the dynamic energy remaining in the geometry. In this study, static damping is applied to dissipate residual dynamic energy without converting it into an implicit analysis. The compressive residual stress distribution is compared between the simulation results for the stainless steel 304 material and the same material subjected to actual laser shock peening. The laser shock peening parameters were 4.2J laser pulse energy, 50% overlap of 3mm diameter of the laser beam and water as a confinement layer. As a result, the compressive residual stress from the surface to the depth direction is similar to both the simulation and the experimental result measured by the hole drilling method.
ARTICLE | doi:10.20944/preprints202105.0509.v1
Subject: Medicine & Pharmacology, Allergology Keywords: depression; mood disorders; inflammation; oxidative stress; nitrosative stress; neuro-immune; antioxidants; psychoneuroimmunology
Online: 21 May 2021 (09:36:47 CEST)
Type 2 diabetes mellitus (T2DM) is frequently accompanied by affective disorders with a prevalence of comorbid depression of around 25%. Nevertheless, the biomarkers of affective symptoms including depression and anxiety due to T2DM are not well established.Aims: This study was conducted to delineate the serum biomarkers predicting affective symptoms due to T2DM above and beyond the effects of insulin resistance and atherogenicity. Methods: The present study delineated the effects of serum levels of copper, zinc, β-arrestin-1, FBXW7, lactosylceramide (LacCer), serotonin, albumin, calcium, magnesium, IR and atherogenicity on severity of depression and anxiety in 58 men with T2DM and 30 healthy male controls. Severity of affective symptoms was assessed using the Hamilton Depression and Anxiety rating scales.Results: We found that 61.7% of the variance in affective symptoms was explained by the multivariate regression on copper, β-arrestin-1, calcium, and insulin resistance coupled with atherogenicity, while 44.4% of the variance in the latter was explained by copper, β-arrestin-1, LacCer (all positively) and calcium and FBXW7 (both negatively). Copper and LacCer (positive) and calcium and BXW7 (inverse) had significant specific indirect effects on affective symptoms which were mediated by insulin resistance and atherogenicity. Copper, β-arrestin-1, and calcium were associated with affective symptoms above and beyond the effects of insulin resistance and atherogenicity.Discussion: T2DM and affective symptoms share common pathways namely increased atherogenicity, insulin resistance, copper, and β-arrestin-1, and lowered calcium, whereas copper, β-arrestin-1, calcium, LacCer, and FBXW7 may modulate depression and anxiety symptoms by affecting T2DM.
ARTICLE | doi:10.20944/preprints202009.0642.v1
Subject: Life Sciences, Biochemistry Keywords: copper; mercury; cadmium; oxidative stress; protein carbonylation; translation factors; oxidative stress biomarkers
Online: 26 September 2020 (14:46:39 CEST)
The impact of metals bioaccumulation on marine organisms is under investigation. This study was designed to determine the association of oxidative stress in mussels Mytilus galloprovincialis induced by seawater enriched with trace metals with protein synthesis. Mussels were exposed to 40 μg/L Cu, 30 μg/L Hg, or 100 μg/L Cd for 5 and 15 days, and the pollution effect was evaluated by measuring established oxidative biomarkers. The results showed damage on the protein synthesis machine integrity and specifically, on translation factors and ribosomal proteins expression and modifications. Exposure of mussels to all metals caused oxidative damage that was milder in the cases of Cu and Hg, and more pronounced for Cd. However, after prolonged exposure of mussels to Cd (15 days), the effects receded. These changes that perturb protein biosynthesis can serve as a great tool for elucidating the mechanisms of toxicity and could be integrated in biomonitoring programs.
ARTICLE | doi:10.20944/preprints202009.0610.v1
Subject: Medicine & Pharmacology, Allergology Keywords: mood disorders; major depression; inflammation; neuro-immune; oxidative stress; nitrosative stress; biomarkers
Online: 25 September 2020 (11:48:43 CEST)
Current diagnoses of mood disorders are not cross validated. The aim of the current paper is to explain how machine learning techniques can be used to a) construct a model which ensembles risk/resilience (R/R), adverse outcome pathways (AOPs), staging, and the phenome of mood disorders, and b) disclose new classes based on these feature sets. This study was conducted using data of 67 healthy controls and 105 mood disordered patients. The R/R ratio, assessed as a combination of the paraoxonase 1 (PON1) gene, PON1 enzymatic activity, and early life time trauma (ELT), predicted the high-density lipoprotein cholesterol – paraoxonase 1 complex (HDL-PON1), reactive oxygen and nitrogen species (RONS), nitro-oxidative stress toxicity (NOSTOX), staging (number of depression and hypomanic episodes and suicidal attempts), and phenome (the Hamilton Depression and Anxiety scores and the Clinical Global Impression; current suicidal ideation; quality of life and disability measurements) scores. Partial Least Squares pathway analysis showed that 44.2% of the variance in the phenome was explained by ELT, RONS/NOSTOX, and staging scores. Cluster analysis conducted on all those feature sets discovered two distinct patient clusters, namely 69.5% of the patients were allocated to a class with high R/R, RONS/NOSTOX, staging, and phenome scores, and 30.5% to a class with increased staging and phenome scores. This classification cut across the bipolar (BP1/BP2) and major depression disorder classification and was more distinctive than the latter classifications. We constructed a nomothetic network model which reunited all features of mood disorders into a mechanistically transdiagnostic model.
REVIEW | doi:10.20944/preprints201807.0052.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Plant stress, abiotic stress, biotic stress, metabolomics, phytometabolomics, sensomics, phytohormonics, LC-MS/MS, NMR, targeted metabolomics, untargeted metabolomics, functional food.
Online: 3 July 2018 (14:18:19 CEST)
The breeding of stress-tolerant cultivated plants that would allow for a reduction in harvest losses and undesirable decrease in quality attributes requires a new quality of knowledge on molecular markers associated with relevant agronomic traits, on quantitative metabolic responses of plants on stress challenges, and on the mechanisms controlling the biosynthesis of these molecules. By combining metabolomics with genomics, transcriptomics and proteomics datasets a more comprehensive knowledge of the composition of crop plants used for food or animal feed is possible. In order to optimize crop trait developments, to enhance crop yields and quality, as well as to guarantee nutritional and health factors, that provides the possibility to create functional food or feedstuffs, the knowledge about the plants’ metabolome is crucial. Next to classical metabolomics studies, this review focusses on several metabolomics based working techniques, such as sensomics, lipidomics, hormonomics and phytometabolomics, which were used to characterize metabolome alterations during abiotic and biotic stress, to find resistant food crops with a preferred quality or at least to produce functional food crops are highlighted.
ARTICLE | doi:10.20944/preprints202211.0225.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: LMO7, secretome, FAK. hypertonicity, osmotic stress, epithelial integrity, epithelial barrier, cortical stress fiber
Online: 14 November 2022 (01:16:06 CET)
In kidney, epithelial barrier has diverse functions in body fluid and electrolyte homeostasis, and urine production. Maintaining epithelial integrity fundamentally builds up physiological functionality of the renal epithelial barrier (REB). Specially, the REB) states regularly in osmotic dynamics. The osmotic dynamics gives rise of osmotic pressure that is a physical force. Overloading of osmotic pressure can crack epithelial integrity and damage REB. How REB endures the osmotic pressure force yet remains enigmatic. LMO7 (LIM domain only 7) is a protein associated with cell-cell junctional complex and cortical F-actin. LMO7 upregulation was observed in cells cultured in hypertonic condition. In kidney, LMO7 predominantly distributes in epithelial cells in renal tubules. Hypertonic stimulation leads to assembly of LMO7 and F-actin in cortical stress fibers in renal epithelial cells. Hypertonic-isotonic alternation as pressure force pushing plasma membrane inward/outward was set as osmotic disturbance and was applied to test FAK signaling and LMO7 functioning in maintaining junctional integrity. Along with junctional integrity, LMO7 depleted cells resulted in loss of junctional integrity in the epithelial sheet cultured hypertonic medium or hypertonic-isotonic alternation. On the other hand, FAK inhibited by PF-573228 leads to failure in robust cortical F-actin assembly and association of LMO7 with cortical F-actin in epithelial cells responding upon hypertonic stress. Epithelial integrity in context of osmotic stress, LMO7 and FAK signaling both involves in assembling robust cortical F-actin and maintaining junctional integrity. The LMO7 elaborately manages FAK activation in renal epithelial cells, which was evidently demonstrated in NRK-52E cells who have excessive FAK activation and lost epithelial integrity when cells with LMO7 depletion exposed to hypertonic environment. Our data suggests that LOM7 manages FAK activation and is responsible for maintaining REB under osmotic disturbance.
BRIEF REPORT | doi:10.20944/preprints202207.0144.v1
Subject: Life Sciences, Biochemistry Keywords: Protein Kinase C; PKCeta; autophagy; senescence; chemoresistance; oxidative stress; ER stress; 3MA; chloroquine
Online: 10 July 2022 (06:42:23 CEST)
The emergence of chemoresistance in neoplastic cells is one of the major obstacles in cancer therapy. Autophagy was recently reported as one of the mechanisms that promote chemoresistance in cancer cells by protecting from apoptosis and driving senescence. Thus, understanding the role of autophagy and its underlying signaling pathways is crucial for the development of new therapeutic strategies to overcome chemoresistance. We have previously reported that PKCη is a stress-induced kinase that confers resistance in breast cancer cells against chemotherapy by inducing senescence. Here we show that PKCη promotes autophagy induced by ER and oxidative stress and facilitates the transition from autophagy to senescence. We demonstrate that PKCη knockdown reduces both the autophagic flux and markers of senescence. Additionally, using autophagy inhibitors, such as chloroquine and 3-methyladenine, we show that PKCη and autophagy are required for establishing senescence in MCF-7 in response to oxidative stress. Different drugs used in the clinic are known to induce autophagy and senescence in breast cancer cells. Our study proposes PKCη as a target for therapeutic intervention, acting in synergy with autophagy-inducing drugs, to overcome resistance and enhance cell death in breast cancer.
REVIEW | doi:10.20944/preprints202207.0130.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: Keywords: mitochondria; stress resilience; plasticity; stress; kynurenine; Alzheimer’s disease; neurodegenerative; depression; anxiety; psychiatric
Online: 8 July 2022 (03:56:36 CEST)
Nearly half a century has passed since the discovery of cytoplasmic inheritance of human chloramphenicol resistance. The inheritance was then revealed to take place maternally by mitochondrial DNA (mtDNA). Later, a number of mutations in mtDNA were identified as a cause of severe inheritable metabolic diseases with neurological manifestation, and the impairment of mitochondrial functions has been probed in the pathogenesis of a wide range of illnesses including neurodegenerative diseases. Recently growing number of preclinical studies has revealed that animal behaviors are influenced by the impairment of mitochondrial functions and possibly by the loss of mitochondrial stress resilience. Indeed, as high as 54% of patients with one of the most common primary mitochondrial diseases, mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, present psychiatric symptoms including cognitive impairment, mood disorder, anxiety, and psychosis. Mitochondria are multifunctional organelles which produce cellular energy and play a major role in other cellular functions including homeostasis, cellular signaling, and gene expression, among other. Mitochondrial functions are observed to be compromised and to become less resilient under continuous stress. Meanwhile, stress and inflammation have been linked to the activation of the tryptophan (Trp)-kynurenine (KYN) metabolic system, which observably contributes to development of pathological conditions including neurological and psychiatric disorders. This narrative review discusses the functions of mitochondria and the Trp-KYN system, the interaction of the Trp-KYN system with mitochondria, and the current understanding of the involvement of mitochondria and the Trp-KYN system in preclinical and clinical studies of major neurological and psychiatric diseases.
Subject: Life Sciences, Biochemistry Keywords: gut microbiota; Entamoeba histolytica; resistance to oxidative stress; resistance to nitrosative stress; virulence
Online: 24 February 2021 (16:26:55 CET)
Amebiasis is a disease caused by the unicellular parasite Entamoeba histolytica. In most cases, the infection is asymptomatic but when symptomatic, the infection can cause dysentery and invasive extraintestinal complications. In the gut, E.histolytica feeds on bacteria. Increasing evidences support the role of the gut microbiota in the development of the disease. In this review we will discuss the consequences of E.histolytica infection on the gut microbiota. We will also discuss new evidences about the role of the gut microbiota in regulating the resistance of the parasite to oxi-dative stress and its virulence.
REVIEW | doi:10.20944/preprints202010.0532.v1
Subject: Biology, Anatomy & Morphology Keywords: Biotic stress; Abiotic stress; climate change; Plant Transcription Factors; Food Security; Crop Improvement
Online: 26 October 2020 (14:26:31 CET)
Crop plants should be resilient to climatic factors in order to feed ever-increasing populations. Plants have developed stress-responsive mechanisms by changing their metabolic pathways and switching the stress-responsive genes. The discovery of plant transcriptional factors (TFs) as key regulators of different biotic and abiotic stresses have opened up new horizons for plant scientists. TFs perceive the signal and switch certain stress-responsive genes on and off by binding to different cis-regulatory elements. The above 50 species of plant TFs have been reported in nature. DREB, bZIP, MYB, NAC, Zinc-finger, HSF, Dof, WRKY, and NF-Y are important with respect to biotic and abiotic stresses whereas the role of many TFs is yet to explore. In this review, we summarize the role of different stress-responsive TFs with respect to biotic and abiotic stresses. Further, challenges and future opportunities linked with TFs for developing climate-resilient crops are also elaborated.
ARTICLE | doi:10.20944/preprints202007.0136.v1
Subject: Life Sciences, Biochemistry Keywords: thioredoxin reductase; oxidative stress; nitrosative stress; theta burst stimulation; experimental autoimmune encephalomyelitis; rats
Online: 7 July 2020 (17:30:22 CEST)
Cortical theta burst stimulation (TBS) structured as intermittent (iTBS) and continuous (cTBS) could prevent the progression of the experimental autoimmune encephalomyelitis (EAE). The interplay of brain antioxidant defense systems against overproduction of reactive oxygen, nitrogen, and thiol species induced by EAE has not been entirely investigated, just as the effect of iTBS or cTBS on oxidative-nitrogen stress (ONS) in EAE rats. Dark Agouti strain female rats were tested for the effects of EAE and TBS. The rats were randomly divided into the following groups: C - control, EAE - rats immunized for EAE, CFA - rats immunized with Complete Freund's adjuvant; iTBS and cTBS groups, and EAE+iTBS and EAE+cTBS - health and EAE rats exposed to iTBS and cTBS, respectively; EAE+iTBSsh and EAE+cTBSsh - sham stimulated EAE rats with the same noise artifacts of iTBS and cTBS, respectively. Superoxide dismutase activity, levels of superoxide anion (O2•-), lipid peroxidation, glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) and thioredoxin reductase (TrxR) activity were analyzed in rat spinal cords homogenates. The severity of EAE clinical coincided with the climax of ONS, based on the increase of superoxide anion and lipid peroxidation; depletion of total thiols, GSH and NADPH; and decrease of SOD activity. The TrxR imposed the most sensitive response against the applied central nervous system (CNS) stressors to rats. We concluded that the TrxR upregulation meritoriously compensates decreased ROS sequestrating and GSH systems in EAE. Both iTBS and cTBS modulate the biochemical environment at a distance from the area of stimulation against ONS, accomplish a similar effect on TrxR activity to EAE and healthy rats, and alleviate symptoms of EAE.
ARTICLE | doi:10.20944/preprints202301.0574.v1
Online: 31 January 2023 (06:21:55 CET)
Melatonin (MT) controls various physiological functions and enhances plant drought tolerance in response to environmental stressors, including water deficit. This study aimed to evaluate the effect of exogenous MT on the morphophysiological attributes of Ranunculus asiaticus under normal and drought conditions. R. asiaticus seedlings were divided into drought-stress and control groups and subjected to foliar application of MT at various concentrations (0, 50, 100, and 200 μM) four times during the study. The drought-stress group exhibited considerably decreased shoot length, leaf number, leaf area, fresh and dry vegetative weights, total chlorophyll and carotenoid contents, and relative water content; delayed emergence of flower stalks; and increased relative electrolyte leakage compared with well-watered plants. Conversely, foliar application of MT notably increased growth parameters compared with their no-treatment counterparts. Foliar treatment with 200 µM MT resulted in the most significant growth response in R. asiaticus under normal or drought-stress conditions. Moreover, compared with no treatment, exogenously applied MT induced the appearance of flower buds and increased relative water and proline contents as well as peroxidase activity while reducing electrolyte leakage. Regarding tolerance index percentages, higher peroxidase and proline contents indicated their suitability for use as markers for drought tolerance, supporting the effective role of exogenous MT in enhancing the adaptability of Ranunculus to drought stress.
REVIEW | doi:10.20944/preprints202109.0310.v1
Online: 17 September 2021 (12:08:15 CEST)
Cool-season grasses are the most common forage types in livestock operations and amenities. Several of the cool-season grasses establish mutualistic associations with an endophytic fungus of the Epichloe genus. The grasses and endophytic fungi have evolved over a long period of time to form host-fungus specific relationships that confer protection for the grass against various stressors in exchange for housing and nutrients to the fungus. This review provides an overview of the mechanisms by which Epichloe endophytes and grasses interact, including molecular pathways for secondary metabolite production. It also outlines specific mechanisms by which the endophyte helps protect the plant from various abiotic and biotic stressors. Finally, the review provides information on how Epichloe infection of grass and stress affect the rhizosphere environment of the plant.
ARTICLE | doi:10.20944/preprints202104.0497.v1
Online: 19 April 2021 (14:30:34 CEST)
In recent years cultivated soils have been increasingly supplemented with nutrients that at low doses are necessary for proper plant functioning but become toxic at high doses. New methods are needed to prevent these destructive actions, and for this reason we studied the effects of two elements – Mn treated as a stressor and Se treated as a potential defense in two wheat cultivars. The intensity of stress was manifested in tissue browning and weight reduction and was determined by an increase in lipid peroxidation and quantitative analysis of hydrogen peroxide levels. It was found that the excess of Mn in the substrate caused more intense changes in these indicators in the root system than in the leaves, and that Se presence partly eliminated the stress evoked effects. Moreover, Mn-treatment was accompanied by a greater absorption of this element by the roots, and a reduced uptake of other elements (K, Fe, S, P), with the exception of Ca, an increase in which was observed especially in the additional presence of Se. It was suggested that the rise in Ca level can lead to modification of cell differentiations and may be one of the steps in defense mechanisms. The change in the direction of cell differentiation in the apical part of the root was observed microscopically under Mn stress and was accompanied by a quantitative increase in 5-met C. Based on DNA methylation profiles detected by MSAP we concluded that various types of methylation sites may be activated under Mn treatment in roots.
COMMUNICATION | doi:10.20944/preprints202005.0446.v1
Online: 27 May 2020 (08:29:53 CEST)
Why animals sleep is an outstanding open question. Information about the toxic byproducts of aerobic cellular respiration along with the analysis of patterns in animal size, sleep needs, dietary-type, metabolism, number of heart beats, transportation-network design, and transportation energetics/dynamics suggest that the function of sleep is to maximize the time an animal has to perform its life functions given the finite and constant number of lifetime heart beats it has. Sleep slows down metabolism, and the heart rate, thereby decreasing the load of toxic reactive oxygen species in the cell and extending the cell’s lifetime/proper-functioning. I argue that this is used to maximize the time an animal spends in its ‘effective environment’, which is defined as the period in the light cycle (day or night) where the essential life-functions of that animal (like finding resources, finding sex, hunting) are better achieved. Larger, slow-metabolizing animals need less sleep because their large-bodily-networks and slow metabolisms keep their heart rates relatively low, resulting in a lower rate of oxidative damage, and more relative time in the ‘effective environment’ to get their essential life-functions accomplished.
ARTICLE | doi:10.20944/preprints202003.0132.v1
Online: 8 March 2020 (04:40:36 CET)
Body temperature responses were recorded during phases of work (waiting to work in close proximity to search site, active work in a search site, and post-work recovery crated in vehicle) in human remains detection dogs during search training. State or federally certified human remains detection dogs (n = 8) completed eight iterations of searching, rotating through six different types of search environments to detect numerous scent sources including partial and complete, buried, hidden, or fully visible human remains. Internal temperature (Tgi) of the body was measured continuously using an ingestible thermistor in the gastrointestinal tract. Mean total phase times were: waiting to work: 9.17 minutes (± 2.27); active work: 8:58 minutes (± 2:49); and post work recovery: 24:04 minutes (± 10.59). Tgi was impacted by phase of work (P < 0.001) with a small increase during active work, with mean peak temperature 39.4 °C (± 0.34 ºC) during that period. Tgi continued to increase for a mean of 7:37 (± 6:04) minutes into the post-work recovery phase in the handler’s vehicle with a mean peak Tgi of 39.66 °C (± 0.41 ºC). No significant increase in temperature was measured during the waiting to work phase, suggesting anticipation of work did not appear to contribute to overall body temperature increase during the waiting to work recovery cycle. Continued increase of gastrointestinal body temperature several minutes after cessation of exercise indicates that risk of heat injury does not immediately stop when the dog stops exercising, although none of the dogs in this study reached clinically concerning body temperatures or displayed any behavioral signs suggestive of pending heat injury. More work is needed to better understand the impact of vehicle crating on post-work recovery temperatures in dogs.
Subject: Materials Science, Nanotechnology Keywords: femtosecond laser; birefringence; stress; sapphire
Online: 23 August 2019 (09:49:21 CEST)
Birefringence of 3 × 10-3 is demonstrated inside cross-sectional regions of 100 µm, inscribed by axially stretched Bessel-beam-like fs-laser pulses along the c-axis inside sapphire. A high birefringence and retardance of λ/4 at mid-visible spectral range (green) can be achieved utilizing stretched beams with an axial extension of 30-40 µm. Conditions of laser writing chosen ensure that there are no formations of self-organised nano-gratings. This method can be adopted for the creation of polarisation optical elements and fabrication of spatially varying birefringent patterns for optical vortex generation.
ARTICLE | doi:10.20944/preprints201904.0107.v2
Online: 15 May 2019 (07:47:16 CEST)
Eyes are quintessential complex traits and our understanding of their evolution guides models of trait evolution in general. A long-standing account of eye evolution argues natural selection favors morphological variations that allow increased functionality for sensing light (Darwin 1859; v. Salvini-Plawen and Mayr 1977; Nilsson and Pelger 1994; Nilsson 2013). While certainly true in part, this focus on visual performance does not entirely explain why diffuse photosensitivity persists even after eyes evolve, or why eyes evolved many times, each time using similar building blocks. Here we briefly review a vast literature indicating most genetic components of eyes historically responded to stress caused directly by light, including UV damage of DNA, oxidative stress, and production of aldehydes. We propose light-induced stress had a direct and prominent role in the evolution of eyes by bringing together genes to repair and prevent damage from light-stress, both before and during the evolution of eyes themselves. Stress-repair and stress-prevention genes were perhaps originally deployed as plastic responses to light and/or as beneficial mutations genetically driving expression where light was prominent. These stress-response genes sense, shield, and refract light but only as reactions to ongoing light stress. Once under regulatory-genetic control, they could be expressed before light stress appeared, evolve as a module, and be influenced by natural selection to increase functionality for sensing light, ultimately leading to complex eyes and behaviors. Recognizing the potentially prominent role of stress in eye evolution invites discussions of plasticity and assimilation and provides a hypothesis for why similar genes are repeatedly used in convergent eyes. Broadening the drivers of eye evolution encourages consideration of multi-faceted mechanisms of plasticity/assimilation and mutation/selection for complex novelties and innovations in general.
ARTICLE | doi:10.20944/preprints201705.0022.v1
Online: 2 May 2017 (04:58:58 CEST)
Transposable elements (TEs) are highly abundant in plant genomes. Environmental stress is one of the critical stimuli that activate TEs. We analyzed a heat-activated retrotransposon named ONSEN in cruciferous vegetables. The multiple copies of ONSEN-like elements (OLEs) were found in all the cruciferous vegetables that were analyzed. The copy number of OLE was abundant in Brassica oleracea, which includes cabbage, cauliflower, broccoli, Brussels sprout, and kale. Phylogenic analysis demonstrated that some OLEs transposed after the allopolyploidization of parental Brassica species. Furthermore, we found that the increasing number of OLEs in B. oleracea appeared to be induced transpositional silencing by epigenetic regulation, including DNA methylation. The results of this study would be relevant to the understanding of evolutionary adaptations to thermal environmental stress in different species.
REVIEW | doi:10.20944/preprints201611.0087.v1
Online: 17 November 2016 (10:40:58 CET)
Oxidative stress occurs when cells are exposed to elevated levels of reactive oxygen species that could damage biological molecules. One bacterial response to oxidative stress involves disulfide bond formation either between protein thiols or between protein thiols and low-molecular-weight thiols. Bacillithiol was recently identified as a major low-molecular-weight thiol in Bacillus subtilis and related Firmicutes. Four genes (bshA, bshB1, bshB2 and bshC) are involved in bacillithiol biosynthesis. The bshA and bshB1 genes are part of a seven-gene operon (ypjD), which includes the essential gene cca, encoding CCA-tRNA nucleotidyltransferase. The inclusion of cca in the operon containing bacillithiol biosynthetic genes suggests that the integrity of the 3’ terminus of tRNAs may also be important in oxidative stress. Addition of the 3´ terminal CCA sequence by CCA-tRNA nucleotidyltransferase to give a mature tRNA and functional molecules ready for aminoacylation plays an essential role during translation and expression of the genetic code. Any defects in these processes, for example, the accumulation of shorter and defective tRNAs under oxidative stress, could exert a deleterious effect on cells. This review summarizes the physiological link between tRNACys regulation and oxidative stress in Bacillus.
REVIEW | doi:10.20944/preprints202210.0013.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: selenium; oxidative stress; serotonin; glutamate; anxiety disorders; obsessive-compulsive disorders; post-traumatic stress disorder
Online: 3 October 2022 (15:17:24 CEST)
Anxiety disorders are among the most common mental disorders worldwide, and often respond incompletely to existing treatments. Selenium, a micronutrient that is a component of several biologically active selenoproteins, is also involved in several aspects of brain functioning, and may exert antidepressant and anxiolytic effects through multiple pathways. The current paper is a scoping review of translational, observational and interventional evidence on the potential role of selenium and its compounds in the management of anxiety and related disorders. Evidence from animal models suggests that this approach may be promising. Though evidence from observational studies in humans is inconsistent and affected by several confounding factors, the available evidence from randomized controlled trials suggests that selenium supplementation may be beneficial in the management of certain anxiety-related conditions, such as anxiety in medically ill patients, prevention of anxiety following exposure to traumatic stress, and obsessive-compulsive disorder. This paper provides a critical evaluation of the existing evidence base, including unanswered questions that could serve as the focus of further research, and outlines the potential benefits and risks associated with the use of selenium in anxiety disorders.
ARTICLE | doi:10.20944/preprints201810.0211.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: lipoprotein; extracellular vesicles; exosome; ectosome; stress response; resistant cancer; metastatic cancer; heat shock stress
Online: 10 October 2018 (09:44:17 CEST)
Resistant cancer often shows a particular secretory trait such as heat shock proteins (HSPs) and extracellular vesicles (EVs), including exosomes and oncosomes surrounded by lipid bilayers. Lipoproteins are biochemical assemblies that transport hydrophobic lipid (a.k.a. fat) molecules in body fluid and are composed of a single-layer phospholipid and cholesterol outer shell, lipids molecules within the particles, and apolipoproteins embedded in the membrane. However, lipoprotein storage and secretion by cancer cells have not well-investigated yet. We found lipoproteins were stored and abundantly secreted by neuroendocrine, castration-resistant prostate cancer (NEPC / CRPC) cells but barely secreted by colon cancer cells and oral squamous cell carcinoma (OSCC) cells. In addition, large EVs (approx. 300 nm diameter) and potential oncosomes were released by CRPC and OSCC cells. Proteomics revealed that CRPC cells secreted EVs enriched with tetraspanins and extracellular matrices which were reduced upon heat shock stress and alternatively lipoproteins and HSPs were secreted upon stress. Heat shock stress triggered secretion of lipoprotein-EV complexes that contained apolipoprotein A, B, C and E. These data suggested that vesicular assembly composed of EVs and lipoproteins enriched with cholesterols and phospholipids may be stored in resistant cancer cells but released upon cell stress that is increased in cancer therapies.
ARTICLE | doi:10.20944/preprints201910.0322.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Parentalstress; Maternal stress; Heart rate variability as an index of parental stress; Socio-economic; demographic; environmental and gender factors associated with maternal stress
Online: 28 October 2019 (12:06:26 CET)
Parental stresses are normal responses to raising children. They are affected by stresses parents and children accumulate and bring to their interrelations. Background factors like economic difficulties or the relations between the parents may affect parental stresses as well as demographic and environmental factors like noise and access to urban parks. Most studies on parental stress are based on a verified psychological questionnaire. We suggest using frequency domain heart rate variability index (HRV) to measure parental stress enabling, by thus, the measurement of physiological aspects of stress and risk to health. Parental stress is measured as the difference between HRV accumulated at home while staying with the children and without the husband and HRV measured in the neighborhood while staying without the children and the husband. We use the index to compare differences among Muslim and Jewish mothers in exposure to maternal stress at their homes and to expose the factors that predict differences in maternal stress. We found that Muslim mothers suffer from home-related maternal stress while Jewish mother do not. Number of children and ethnically related environmental aspects predict differences in maternal stress between Muslim and Jewish mothers. Muslims' lower access to parks stems from lack of home garden and parks in their neighborhoods in the Arab towns but mainly by restrictions on Muslim women's' freedom of movement to parks. Despite differences in levels of noise at home and in the status of the mother in the household, these factors did not predict differences in parental stress. Instead, the study highlights the crucial role of greenery and freedom of movement to parks in moderating home-related maternal stress.
REVIEW | doi:10.20944/preprints201712.0042.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: corticotropin releasing factor; irritable bowel syndrome (IBS); maternal separation (MS); neurotransmitters; pain; psychosocial stress; visceral hyperalgesia; water avoidance stress (WAS); wrap restrain stress (WRS)
Online: 7 December 2017 (07:39:49 CET)
Irritable bowel syndrome (IBS) is one of the most common gastrointestinal diseases in humans. It is characterized by visceral pain and/or discomfort, hypersensitivity and abnormal motor responses along with change in gut habits. Although the etio-pathogenesis of IBS is only partially understood, a main role has been attributed to psychosocial stress of different origin. Animals models such as neonatal maternal separation, water avoidance stress and wrap restraint stress have been developed as psychosocial stressors in the attempt to reproduce the IBS symptomatology and identify the cellular mechanisms responsible for the disease. The study of these models has led to the production of drugs potentially useful for IBS treatment. This review intends to give an overview on the results obtained with the animal models; to emphasize the role of the enteric nervous system in IBS appearance and evolution and as a possible target of drug therapies.
ARTICLE | doi:10.20944/preprints202202.0357.v1
Subject: Life Sciences, Molecular Biology Keywords: granulosa cells; heat stress; apoptosis; oxidative stress; RNA-seq; transcriptomics; differentially expressed genes; signaling pathways
Online: 28 February 2022 (11:08:42 CET)
Heat stress affects the granulosa cells (GCs) and ovarian follicular microenvironment, causing poor oocyte developmental competence and fertility. This study aimed to investigate the physical responses and global transcriptomic changes in bovine GCs to acute heat stress (43 ℃ for 2 h) in-vitro and gave essential insights into the general interaction at cell–stress nexus. Heat-stressed GCs exhibited transient proliferation senescence, resumed proliferation at 48 h post-stress. While post-stress immediate culture-media change had a relatively positive effect on proliferation resumption. Increased accumulation of reactive oxygen species and apoptosis was observed in heat stress group. In spite of the upregulation of pro-apoptotic and caspase executioner genes, antioxidants and anti-apoptotic genes were also upregulated in heat-stressed GCs. Progesterone and Estrogen hormones along with steroidogenic genes expression, declined significantly, in spite of the upregulation of genes involved in cholesterol synthesis. Out of 12385 differentially expressed genes (DEGs), 330 significant DEGs (75 upregulated, 225 downregulated) were subjected to KEGG functional pathway annotation, gene ontology enrichment, and STRING network analyses. Based on the manual query of DEGs, pathway and enrichment analyses, a vast interplay observed among all major signaling pathways strongly evidence the repression of cellular transcriptional and proliferation activity, averting the effects of heat stress through remodeling of cellular structural proteins and energetic-homeostasis. This study presents detailed responses of acute heat-stressed GCs at physical, transcriptional, and pathway levels and presents interesting insights into future studies regarding GCs adaptation and their interaction with oocyte and reproductive system at ovarian level.
REVIEW | doi:10.20944/preprints202007.0333.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Abiotic stress; Biotic stress; Adaptation; Climate change; Diaseases; Diversity; Genetic Resources; Gene bank; Wild relatives
Online: 15 July 2020 (11:21:07 CEST)
Abstract: A large number of collecting expeditions were launched in regions of ‘centers of diversity’ and hundreds of thousands of sample have been collected and stored in gene banks as ‘genetic resources’. So far, only a small number of the samples have been evaluated for their biotic and abiotic stress tolerance. Now, their time to become useful has come. A new global phenomenon has arisen – climate change. The crop genetic resources and their wild progenitors that have survived countless years of changing environment during the last 11,000 years could harbor genes that may be useful under the new growing conditions and environmental factors thrown up by climate change and global warming. With the deployment of modern bio-engineering techniques selected genes or gene fragments can be transferred from genetic resources to modern varieties of crop plants to make them well-prepared to mitigate the effects of global warming and climate change. The latter is the most serious issue facing plant breeders today. New pests and diseases could affect crop production. These review paper discusses various impacts and issues as a result of this phenomenon and suggest ways to safeguard our most important crops through better management of crop plant genetic resources in the near future.
REVIEW | doi:10.20944/preprints201801.0223.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: abiotic stress; antioxidant defense; enzyme regulations; oxidative stress; plant nutrients; reactive oxygen species; soil fertility
Online: 24 January 2018 (07:01:05 CET)
Among the plant nutrients potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of plant structure but also plays regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, enzyme activation. There are several physiological processes like stomatal regulation and photosynthesis are dependent on K. In the recent decades K was found to provide abiotic stress tolerance. Under salt stress, K helps in maintaining ion homeostasis and regulation of osmotic balance. Under drought stress condition K regulates the stomatal opening and makes the plants adaptive to water deficit. Many reports provided the notion that K enhances the antioxidant defense in plants and therefore, protects the plants from oxidative stress under various environmental adversities. Also, it provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although a considerable progress in understanding K-induced abiotic stress tolerance in plants has been achieved the exact molecular mechanisms of such protections are still under research. In this review, we summarized the recent literature on the biological functions of K, its uptake, and translocation and its role in plant abiotic stress tolerance.
REVIEW | doi:10.20944/preprints202301.0321.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Anti-inflamotry; antioxidant; oxidative stress; zebrafish
Online: 18 January 2023 (07:06:34 CET)
This work is based on identifying the analysis techniques used to evaluate the antioxidant and anti-inflammatory effects using the zebrafish model. In this context, a literature review was performed with the Web of Science database. We used the terms zebra fish, antioxidant, anti-inflammatory, model, and Danio rerio. Fifty articles were reviewed, of which thirty-three were chosen to perform this review and were classified according to the source of plant extracts, compounds extracted from plants, chemical compounds, and other sources. This paper is an effort to provide a literature review on zebrafish models and elucidate their pros and cons to evaluate anti-inflamatory and antioxidant activity.
ARTICLE | doi:10.20944/preprints202212.0526.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: hyperglycemia; dyslipidemia; oxidative stress; Gymnema Sylvestre
Online: 28 December 2022 (03:31:07 CET)
The effect of Gymnema Sylvestre supplementation on beta cell and hepatic activity was explored in an alloxan-induced hyperglycemic rat model. Adult rats were made hyperglycemic via a single inj. (i.p) of Alloxan (120mg/kg b.w). Gymnema Sylvestre was supplemented @250mg/kg and 500mg/kg b.w. Blood glucose levels were constantly monitored. After 21 days, rats were euthanized, and blood and tissues (pancreas and liver) were collected for biochemical, expression, and histological analysis. One-way ANOVA was used to compare the means of different treatment groups. Gymnema Sylvestre significantly reduced blood glucose levels with a subsequent increase in plasma insulin levels in a dosage-dependent manner. Total oxidant status (TOS), malondialdehyde, LDL, VLDL, ALT, AST, triglyceride, total cholesterol, total protein, C-reactive protein, and cortisol levels were reduced significantly in alloxan-treated hyperglycemic rats supplemented with Gymnema Sylvestre as compared to control. Significantly raised paraoxonase, arylesterase, albumin, and HDL levels were also observed in Gymnema Sylvestre supplemented hyperglycemic rats. Increased mRNA expression of Ins-1, Ins-2, Gck, Pdx1, Mafa, and Pax6 were observed, while decreased expression of Cat, Sod1, Nrf2, and NF-kB was observed in the pancreas. Whereas increased mRNA expression of Gck, Irs1, SREBP1c, and Foxk1 and decreased expression of Irs2, ChREBP, Foxo1, and FoxA2 were observed in the liver. The current study indicates the potent effect of Gymnema Sylvestre on the transcription modulation of the insulin gene in the alloxan-induced hyperglycemic rat model. Enhanced plasma insulin levels further help to improve hyperglycemia-induced dyslipidemia through transcriptional modulation of hepatocytes.
ARTICLE | doi:10.20944/preprints202203.0251.v1
Online: 17 March 2022 (10:59:09 CET)
Despite accumulating evidence for the pro-apoptotic role for X-linked inhibitor of apoptosis-associated factor 1 (XAF1), its involvement in endoplasmic reticulum (ER) stress response remains undefined. Here, we report that XAF1 enhances cell sensitivity to ER stress and acts as a switch in unfolded protein response (UPR)-mediated cell-fate decisions favoring apoptosis over adaptive autophagy. XAF1 interacts with and destabilizes ER stress sensor GRP78 through the assembly of zinc finger protein 313-mediated destruction complex. Moreover, XAF1 gene transcription is activated by ER stress through PERK-Nrf2 signaling to direct an adaptive to apoptotic switch of stress response by blocking C-terminus of Hsc70-interacting protein (CHIP)-mediated K63-linked ubiquitination and subsequent phosphorylation of inositol-required enzyme-1α (IRE1α). In tumor xenograft assays, XAF1-/- tumors display substantially lower regression compared to XAF1+/+ tumors in response to cytotoxic dose of ER stress inducer. XAF1 and GRP78 expression show an inverse correlation in human cancer cell lines and primary breast carcinomas. Collectively this study uncovers an important role for XAF1 as a linchpin to govern the sensitivity to ER stress and the outcomes of UPR signaling, illuminating the mechanistic consequence of XAF1 inactivation in tumorigenesis.
REVIEW | doi:10.20944/preprints202106.0515.v1
Subject: Biology, Anatomy & Morphology Keywords: inositol; inositol transporters; vacuole; stress tolerance
Online: 21 June 2021 (14:12:29 CEST)
Inositol transporter (INT) is reputed as the pivotal transporter for vital metabolites like lipids, minerals, and sugars particularly. These transporters play important role in transitional metabolism and various signaling pathways in plants through regulating the transduction of messages from hormones, neurotransmitters, and immunologic and growth factors. Extensive studies have been conducted on animal INT with promising outcomes. However, few recent studies have highlighted the importance and the complexity of INT genes in the regulation of plant physiology stages including growth and tolerance to stress conditions. The present review sum-up the most recent findings on the role of INT or inositol genes in plant metabolisms and the responsive mechanisms that cope with external stressors. Moreover, we highlighted the emerging role of vacuoles and vacuolar inositol transporters in plant molecular transition and their related roles in plant growth and development. Inositol transporters are the essential mediator for the inositol uptake and its intracellular broadcasting for various metabolic pathways where they play crucial roles. Also, so far characterized only in animals, we reported evidence on Na+/inositol transporters H+/inositol symporters and suggested their roles and operating mode in plants. Thus, understanding the INT functioning system, the coordinated movement of inositol, and the relation between inositol generation and other important plant signaling pathways would be an excellent asset for advancement in researches on plant stress adaptation.
REVIEW | doi:10.20944/preprints202106.0464.v1
Online: 17 June 2021 (14:40:02 CEST)
An imbalance in any metabolic system can be traced to its homeostasis. When homeostatic environment is not attainable then there will be a response from the body. A new shift has emerged, “the negative feedback effect of high fructose consumption;” more pain than gain. The human metabolic system daily combat fructose sugar metabolism which emanates from high consumption. This inadvently lead to a chronological series of complications arising from the feedback. These feedbacks play pivotal roles in skeletal muscle damage and other body frameworks, it also fosters toxic advanced glycation end products (AGEs), factors that impose and inflict damaging effects to the body`s energy currency and serious threat to health. These damages are missed or overlooked because of early nonspecific physiological symptoms. High level of fructose has both long- and short-term effects on human metabolic processes. These effects which are majorly through the production of reactive oxygen species (ROS) and other free radicals, are felt in the disruption of biomolecules such as causing DNA mutation, lipid peroxidation etc. these effects in turn lead to various diseases such as cancer, diabetes, atherosclerosis, and other health issues. In this review, we will focus on the damaging effects this sugar has on human health and the present solutions being applied. We will also look at the next step in combatting and controlling these negative feedbacks.
ARTICLE | doi:10.20944/preprints202104.0694.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: Causes, post traumatic stress disorder,refugees
Online: 26 April 2021 (20:51:27 CEST)
Abstract Objectives To assess the causes and risk factors of posttraumatic stress disorder (PTSD) in adult asylum seekers and refugees. To explore whether the causes and risk factors of PTSD, between male and female adult refugees/ asylum seekers is different. Study design Systematic review of current literature. Data Sources PubMed, Web of Science, Scopus and Google Scholar up until February 2019 Method A structured systematic search was conducted in the relevant databases. Papers were excluded, if they failed to meet the inclusion and exclusion criteria. Afterwards, a qualitative assessment was performed on the selected papers. Results 12 Studies were included for the final analysis. All papers were either case studies/report or cross sectional studies. The number of traumatic events experienced by refugees/asylum seekers, is the most frequently reported pre-migration causes for PTSD development. Whilst acculturative stress, is the most common post migration stressor. There were mixed reports, regarding the causes of PTSD between both genders of refugees/asylum seekers. Conclusion This reviews’ findings, have potential clinical application into helping clinicians, to risk stratify refugees/asylum seekers for PTSD development and thus aid in embarking on earlier intervention measures. However, more rigorous research similar to this one, is needed for it to be implemented into clinical practice.
REVIEW | doi:10.20944/preprints202102.0343.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: Chronic stress; Recovery; Burnout; Exhaustion; Maintenance
Online: 17 February 2021 (07:45:19 CET)
Burnout is common in many countries and is associated with several other problems, such as depression, anxiety, insomnia and memory deficits, and prospectively it predicts long-term sick-leave, cardiovascular disease and death. Clinical burnout or its residual symptoms often last several years and a common assumption is that recovery takes a long time by nature despite full time sick-leave and absence of work stress. Literature suggests models that hypothetically explain the development, but not maintenance, of the syndrome. Based on cognitive and behavioral principles and stress theory this paper describes a theoretical model explaining how clinical burnout can develop and be maintained. While the development of clinical burnout is mainly explained by prolonged stress reactions and disturbed recovery processes due to work related stressors, maintenance of the syndrome is particularly explained by prolonged stress reactions and disturbed recovery processes due to the new context of experiencing burnout and being on sick-leave. Worry about acquired memory deficits, passivity and excessive sleep, shame, fear of stress reactions, and the perception of not being safe are examples of responses that can contribute to the maintenance. The model has important implications for research and how to intervene clinical burnout.
ARTICLE | doi:10.20944/preprints202102.0290.v1
Subject: Biology, Anatomy & Morphology Keywords: abiotic stress; strawberry; companion plants; phytoremediation
Online: 11 February 2021 (19:00:26 CET)
Strawberry is a saline sensitive plant adversely affected under slightly or moderately saline conditions. Growth and biochemical parameters of strawberry plants grown under NaCl (0-, 30-, 60-, and 90 mmol L-1) conditions with or without a halophytic companion plant (Portulaca oleracea L.) were investigated in a pot experiment. Salt stress negatively affected the growth, physiological (stomatal conductance, electrolyte leakage, total soluble solids) and biochemical parameters such as chlorophyll contents (chl-a and chl-b), proline, hydrogen peroxide, malondialdehyde, catalase, and peroxidase enzyme activities, lycopene, vitamin C contents along with the mineral uptake of strawberry plants. The companionship of P. oleacea increased fresh weight, dry weight, and fruit average weight and total fruit yield of strawberry plants along with the improvement of physiological and biochemical parameters. This study showed that cultivating of P. oleracea with strawberry plants under salt stress conditions effectively increased strawberry fruit yield and quality. We, therefore, that approaches towards the use of P. oleracea could be an environmentally friendly method that should be commonly practised where salinity is of great concern.
REVIEW | doi:10.20944/preprints202012.0304.v1
Subject: Biology, Anatomy & Morphology Keywords: Vitrification; cooling; abiotic; biotic; stress; browning
Online: 14 December 2020 (08:17:26 CET)
Recent developments in the cryopreservation space has increased the trend in germplasm collections established through cryopreserved in vitro material. Cryopreservation of recalcitrant seeds through embryos and embryonic axes, is not uncommon. Tropical and sub-tropical plants are not acclimated to the cold season, therefore have no in-built natural resilience to the cold. Also, larger seeds from trees, such as avocado (Persea americana Mill.), mango (Mangifera indica) and durian (Durio zibethinus L.) are sensitive to desiccation, chilling and freezing stress, making them unsuitable for seed banking or cryopreservation. Alternatively, as seeds do not carry the same genetic make-up as the mother plant, especially in the context of woody rainforest species of which the cross-pollination is dominant; seed conservation does not serve the purpose of germplasm preservation. Other plant material and methods are needed for these plants to be successfully stored in liquid nitrogen (LN). One such method commonly used is shoot-tip cryopreservation which ensures the clonal fidelity of germplasm. There are many problems when using shoot tips of tropical recalcitrant-seeded species. These include: 1) the toxic effects of cryoprotective agents towards structural integrity; 2) optimum developmental stage for success and 3) oxidative stress associated with excision injury leading to necrosis triggering cell death and hindering regeneration for the shoot tips in culture. A pre-requisite for any cryopreservation system is the availability of an established tissue culture regeneration platform. This review will outline conservation strategies for avocado with special emphasis on attempts and improvements made in the cryopreservation space for storing this horticulturally important crop ‘avocado’ at ultra-low temperatures.
ARTICLE | doi:10.20944/preprints202010.0559.v1
Online: 27 October 2020 (15:27:36 CET)
Introduction: COVID-19 pandemic has affected HCPs in multiple way. It has caused psychological impact in form of anxiety, depression, and insomnia. In this study, we aim to study and compare the stress level, anxiety and depression among HCPs who are posted in special COVID-19 units with the HCPs who are not posted in COVID-19 units.Methods: This cross-sectional study was conducted in June 2020, at various hospitals of Karachi, Pakistan. All health care professionals (HCPs) were invited to participate. A total of 301 HCPs completed this study, who were divided into two groups; those who are posted in COVID-19 ward (Group A) and those who are not (Group B). Psychological Impact was English version of the Depression Anxiety Stress Scale - 21 (DASS-21).Results: In Group A, 70.5% had moderate, severe, or extremely severe depression compared to 49.2% in group B. In Group A, 75.4% had moderate, severe, or extremely severe anxiety compared to 44.7% in group B. In Group A, 80.3% had moderate, severe or extremely severe stress compared to 54.2% in group B. Anxiety, depression and stress were significantly higher in HCPs who were posted in COVID-19 ward compared to those who were not posted in COVID-19 wardConclusion: There was significantly higher anxiety, stress and depression in health care professionals posted in COVID-19 ward. Both the government and health care agencies should take responsibility for protecting the psychological well-being of health care communities all over the world and ensuring a healthy work environment.
Subject: Life Sciences, Biochemistry Keywords: Cyanobacteria; Gene expression; Regulation; Signalling; Stress
Online: 23 October 2020 (12:26:14 CEST)
Cyanobacteria are highly diverse, widely distributed photosynthetic bacteria inhabiting various environments ranging from deserts to the cryosphere. Throughout this range of niches, they have to cope with various stresses and kinds of deprivation which threaten their growth and viability. In order to adapt to these stresses and survive, they have developed several global adaptive responses which modulate the patterns of gene expression and the cellular functions at work. Sigma factors, two-component systems, transcriptional regulators and small regulatory RNAs acting either separately or collectively, for example, induce appropriate cyanobacterial stress responses. The aim of this review is to summarize our current knowledge about the diversity of the sensors and regulators involved in the perception and transduction of light, oxidative and thermal stresses and nutrient starvation responses. The studies discussed here point to the fact that various stresses affecting the photosynthetic capacity are transduced by common mechanisms.
ARTICLE | doi:10.20944/preprints202006.0356.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: anxiety; depression; stress; coronavirus; Dilla; Ethiopia
Online: 30 June 2020 (08:00:58 CEST)
Background: The COVID-19 pandemic is the global public health emergency concern and had an impact on the day to day life of individuals. Its effect on an individual’s mental health is significant to the extent of suicide. Objective: This study aimed to assess the magnitude of psychological problems and their associated factor among communities living in Dilla town in response to the pandemic. Methods: From Apr 1- Apr 15, 2020, a community-based cross-sectional study was conducted using multi-stage sampling techniques. Self-administered the questioner, Depression, Anxiety and Stress Scale (DASS-21), and logistic regression analysis (95% CI, p-value <0.05) was used. Results: This study included 445 respondents with a 94% non- response rate who was living in Dilla town. In total, 34.4% of respondents had a psychological problem (11.4 % mild and 23% moderate level of the psychological problem). Female, Greater secondary level of education, monthly income below 500 ETB, more than three family size, and wearing face mask were variables associated with the outcome variable (p < 0.05). Conclusions: Nearly one-third of the respondents had mild to moderate psychological among communities living in Dilla town. There is a need for mental health support on those identified groups of peoples to enhance their resilience in response to the pandemic.
ARTICLE | doi:10.20944/preprints202006.0222.v1
Subject: Life Sciences, Molecular Biology Keywords: astaxanthin; muscle atrophy; mitochondria; oxidative stress
Online: 17 June 2020 (13:29:15 CEST)
Astaxanthin (AX) is a carotenoid that exerts potent antioxidant activity and acts in the lipid bilayer. This study aimed to investigate the effects of AX on muscle atrophy-mediated disturbance of mitochondria that have a lipid bilayer. Tail suspension was used to establish muscle- atrophied mouse models. AX diet fed to tail-suspension mice prevented loss of muscle weight and decreased myofiber size in the soleus muscle. Additionally, AX improved down-regulation of mitochondrial respiratory chain complexes II and III in the soleus muscle after tail suspension. To confirm the AX phenotype in the soleus muscle, we examined its effects on mitochondria using Sol8 myotubes derived from the soleus muscle. We found that AX was preferentially detected in the mitochondrial fraction; it significantly suppressed mitochondrial complex III-driven production of reactive oxygen species in Sol8 myotubes. Moreover, AX inhibited the activation of caspase 3 via inhibiting the release of cytochrome c into the cytosol in antimycin A-treated Sol8 myotubes. These results suggested that AX inhibited mitochondrial oxidative stress through a mitochondria-mediated apoptosis pathway and thus prevented muscle atrophy.
ARTICLE | doi:10.20944/preprints202002.0448.v1
Subject: Biology, Physiology Keywords: Stress; Hypertension; Microglia; Neuroinflammation; Sympathetic overactivation
Online: 28 February 2020 (16:30:19 CET)
Background: Hypertension is a cardiovascular syndrome with the highest morbidity and mortality worldwide. Hypertension caused by various stress factors is called stress-induced hypertension (SIH). The rostral ventrolateral medulla (RVLM) "neuroinflammatory-sympathetic overactivation" is involved in SIH formation. Melatonin has anti-inflammatory, anti-oxidant and blood pressure lowering effects. The present study is to explore the antihypertensive effects and mechanism of central melatonin which based on microglia derived neuroinflammation. Methods: Stress-induced hypertension (SIH) was induced by electric foot-shock stressors with noise interventions in rats. Melatonin (0.01，0.1，1 mmol/L) was administered to RVLM and then blood pressure (BP) and serum norepinephrine (NE) were monitored to reflect sympathetic vasomotor activity in SIH rats. Excitatory neurotransmitter (Glutamate) and inhibitory neurotransmitter [γ-aminobutyric acid (GABA)] were measured using ELISA kits. Markers of microglia M1 polarization (CD86) and pro-inflammatory cytokines (PICs (IL-1β, TNF-α)) expression in the RVLM were measured by RT-qPCR. Results: (1) Stress-induced increase in blood pressure and serum NE concentration; RVLM microinjection melatonin attenuated the elevation of blood pressure and increase of plasma NE in SIH rats in a dose-dependent manner. (2) The expression of CD86, PICs (IL-1β, TNF-α) and c-fos were increased in SIH rats; RVLM injection melatonin attenuated RVLM neuroinflammation and its effect is concentration-dependent. (3). Stress-induced increase in glutamate concentration in RVLM; RVLM injection melatonin reduced glutamate level and increased GABA level in SIH rats in a concentration-dependent manner. Conclusion: RVLM injection of melatonin inhibits M1 polarization and has anti-hypertensive effects. Melatonin reduces M1 polarization in microglia might be a novel target and a new strategy for anti-stress induced-hypertension.
ARTICLE | doi:10.20944/preprints201909.0059.v2
Subject: Life Sciences, Cell & Developmental Biology Keywords: Oxidative stress, MFN2, mitochondria, fusion/fission
Online: 9 September 2019 (11:46:36 CEST)
Charcot-Marie-Tooth disease is a hereditary polyneuropathy caused by mutations in Mitofusin-2 (MFN2), a GTPase in the outer mitochondrial membrane involved in the regulation of mitochondrial fusion and bioenergetics. Autosomal-dominant inheritance of a R94Q mutation in MFN2 causes the axonal subtype 2A2A which is characterized by early onset and progressive atrophy of distal muscles caused by motoneuronal degeneration. Here, we studied mitochondrial shape, respiration, cytosolic and mitochondrial ATP content as well as mitochondrial quality control in MFN2-deficient fibroblasts stably expressing wildtype or R94Q MFN2. Under normal culture conditions, R94Q cells had slightly more fragmented mitochondria but a similar mitochondrial oxygen consumption, membrane potential and ATP production as wildtype cells. However, when inducing mild oxidative stress 24 h before analysis using 100 µM hydrogen peroxide, R94Q cells exhibited significantly increased respiration but decreased mitochondrial ATP production. This was accompanied by increased glucose uptake and an upregulation of hexokinase 1 and pyruvate kinase M2 suggesting increased pyruvate shuttling into mitochondria. As these changes coincided with decreased levels of PINK1/Parkin-mediated mitophagy in R94Q cells, we conclude that the disease-causing R94Q mutation in MFN2 causes uncoupling of mitochondrial respiration from ATP production by a less efficient mitochondrial quality control triggered by oxidative stress.
REVIEW | doi:10.20944/preprints201811.0189.v4
Online: 28 December 2018 (04:39:00 CET)
The objective of this study was to perform a systematic review and meta-analysis of the articles that addressed the effect BA or carnosine supplementation on physical exercise (PE)-induced oxidative stress (OS). Before May 2018 we searched throughout PubMed, CAPES Periodic and SPORTDiscus human model peer review, randomized control studies with chronic BA or carnosine supplementation on PE-induced OS. A total of 128 citations were found. Only four articles met criteria for inclusion. All four studies used healthy young sedentary, recreationally active or athletic participants. After a chronic BA or carnosine supplementation, the studies evaluated PE-induced OS both immediately and several hours after exercise (0.5 to 48 h). In response to PE-induced OS, when compared to placebo, BA/carnosine supplementation increased total antioxidant capacity [TAC; Effect Size (ES) = 0.35, 95% Confidence Interval (CI) 0.06 to 0.65, p = 0.02] and glutathione (GSH; ES = 0.75, 95% CI 0.32 to 1.19, p = 0.0007) concentrations while decreased direct OS markers (ES = −1.19, 95% CI −1.48 to −0.80, p < 0.01) and superoxide dismutase (SOD) activity (ES = − 0.58, 95% CI −1.10 to −0.06, p = 0.03). BA or carnosine supplementation did not prevent the increase in indirect OS markers (ES: 0.06, 95% CI −0.38 to 0.500, p = 0.80). In humans, following PE-induced OS, initial treatment trials of BA or carnosine supplementation seemed to increase TAC and GSH concentrations, while decreasing SOD activity. Also, albeit mitigating the acute increase in direct OS markers (reactive nitrogen and oxygen species), treatment did not decrease measured values of indirect OS markers (peroxidation or molecule oxidation).
ARTICLE | doi:10.20944/preprints201811.0177.v1
Online: 7 November 2018 (15:17:33 CET)
Adenosine to inosine (A-to-I) RNA editing is a highly conserved regulatory process carried out by adenosine-deaminases (ADARs) on dsRNAs. Although a considerable fraction of the transcriptome is edited, the function of most editing sites is unknown. Previous studies indicate changes in A-to-I RNA editing frequencies following exposure to several stress types. However, the overall effect of stress on the expression of ADAR targets is not fully understood. Here, we performed high-throughput RNA sequencing of wild-type and ADAR mutant C. elegans worms after heat-shock to analyze the effect of heat-shock stress on the expression pattern of genes. We found that ADAR regulation following heat-shock does not directly involve heat-shock related genes. Our analysis also revealed that lncRNAs and pseudogenes, which have a tendency for secondary RNA structures, are enriched among upregulated genes following heat-shock in ADAR mutant worms. The same group of genes is downregulated in ADAR mutant worms under permissive conditions, which is likely, considering that A-to-I editing protects endogenous dsRNA from RNA-interference (RNAi). Therefore, temperature increases may destabilize dsRNA structures and protect them from RNAi degradation, despite the lack of ADAR function. These findings shed new light on the dynamics of gene expression under heat-shock in relation to ADAR function.
ARTICLE | doi:10.20944/preprints202209.0251.v1
Subject: Materials Science, Polymers & Plastics Keywords: fiber metal laminate; hybrid laminate; residual stress; asymmetric laminate; process monitoring; curvature analysis; stress-free temperature
Online: 19 September 2022 (02:03:21 CEST)
Residual stresses in fiber metal laminates (FML) inevitably develop during the manufacturing process. The main contributor to these stresses is the difference in the coefficients of thermal expansion (CTE) between fibers and metal in combination with high process temperatures. To quantify these stresses, the use of specimens with an asymmetric layup is an easily adaptable method. The curvature that develops after the manufacturing of flat laminates with an asymmetrical layer stack is a measure of the level of residual stresses evolving during cure. However, the accuracy of the curvature evaluation is highly dependent on specimen design and other influencing parameters. In this work a large set of FML specimens is investigated to identify relevant influencing parameters and derive conclusions about specimen design and evaluation techniques. For certain layups and process parameters, there is a good correlation between the curvature and the stress-free temperature, which is further covered by analytical solutions for bimetals. This correlation is the basis to transfer curvature into a stress-free temperature that can consequently be used for the quantification of residual stress levels in more complex FMLs. The transfer is validated by in-situ strain measurements during cure using a strain gage technique. Based on the results, the application of asymmetric specimens for residual stress characterization in more complex laminates is presented in the form of a workflow.
ARTICLE | doi:10.20944/preprints202001.0244.v1
Subject: Life Sciences, Molecular Biology Keywords: Stress; epigenetics; senescence; cognition; age-related cognitive decline; Alzheimer’s disease; SAMP8; SAMR1; oxidative stress; inflammation; autophagy
Online: 21 January 2020 (11:44:35 CET)
Cognitive and behavioural disturbances are growing public healthcare issue for the modern society, as stressful lifestyle is becoming more and more common. Besides, several pieces of evidence state that environment is crucial in the development of several diseases as well as compromising healthy aging. Therefore, it is important to study the effects of stress on cognition and its relationship with aging. To address these queries, Chronic Mild Stress (CMS) paradigm was used in the senescence-accelerated mouse prone 8 (SAMP8) and resistant 1 (SAMR1). On one hand, we determined the changes produced in the three main epigenetic marks after 4 weeks of CMS treatment, such as a reduction in histone posttranslational modifications and DNA methylation, and up-regulation or down-regulation of several miRNA involved in different cellular processes in mice. In addition, CMS treatment induced reactive oxygen species (ROS) accumulation and loss of antioxidant defence mechanisms, as well as inflammatory signalling activation through NF-κB pathway and astrogliosis markers, like Gfap. Remarkably, CMS altered mTORC1 signalling in both strains, decreasing autophagy only in SAMR1 mice. We found a decrease in glycogen synthase kinase 3 β (GSK-3β) inactivation, hyperphosphorylation of Tau and an increase in sAPPβ protein levels in mice under CMS. Moreover, reduction in the non-amyloidogenic secretase ADAM10 protein levels was found in SAMR1 CMS group. Consequently, detrimental effects on behaviour and cognitive performance were detected in CMS treated mice, affecting mainly SAMR1 mice, promoting a turning to SAMP8 phenotype. In conclusion, CMS is a feasible intervention to understand the influence of stress on epigenetic mechanisms underlying cognition and accelerating senescence.
REVIEW | doi:10.20944/preprints201712.0052.v1
Subject: Biology, Other Keywords: cell programming; stress resistance; gene overexpression; radiation; oxidative stress; chemical genotoxins; malignant transformation; diversity of mechanisms
Online: 9 December 2017 (13:26:14 CET)
Different organisms, cell types, and even similar cell lines can dramatically differ in resistance to genotoxic stress. This testifies to the wide opportunities for genetic and epigenetic regulation of stress resistance. These opportunities could be used to increas the effectiveness of cancer therapy, develop new varieties of plants and animals, and search for new pharmacological targets to enhance human radioresistance, for example, for -manned deep space expeditions. Based on the comparison of transcriptomic studies in cancer cells, in this review we propose that there is a high diversity of genetic mechanisms of development of genotoxic stress resistance. This review focused onpossibilities and limitations of the proposed regulation of the resistance of normal cells whole organisms to genotoxic and oxidative stress by overexpressing of stress-response genes. Moreover, the existing experimental data on the effect of such overexpression on the resistance of cells and organisms to various genotoxic agents has been analyzed and systematized. We suggest that the recent advances in the development of multiplex and highly customizable gene overexpression technology that utilizes the mutant Cas9 protein and the wealth of available data on gene functions and their signal networks open new opportunities for research in this field.
Subject: Life Sciences, Biochemistry Keywords: glucose; glycogen; gluconeogenesis; early life adversity; acute stress; chronic stress; psychosocial stress; hypothalamus-pituitary-adrenal axis; ageing; immuno-senescence; inflamm-ageing; Developmental origins of health and disease
Online: 23 March 2021 (09:04:41 CET)
The physiological response to a psychological stressor broadly impacts energy metabolism. In-versely, changes in energy availability affect the physiological response to the stressor in terms of hypothalamus, pituitary adrenal axis (HPA) and sympathetic nervous system activation. Glu-cocorticoids, the endpoint of the HPA axis, are critical checkpoints in endocrine control of ener-gy homeostasis and have been linked to metabolic diseases including obesity, insulin resistance and type 2 diabetes. Glucocorticoids, through the glucocorticoid receptor, activate transcription of genes associated with glucose and lipid regulatory pathways and thereby control both physi-ological and pathophysiological systemic energy homeostasis. Here, we summarize the current knowledge of glucocorticoid functions in energy metabolism and systemic metabolic dysfunc-tion, particularly focusing on glucose and lipid metabolism. There are elements in the external environment that induce lifelong changes in the HPA axis stress response and glucocorticoid levels, the most prominent are early-life adversity, or exposure to traumatic stress. We hypothe-sise that when the HPA axis is so disturbed after early-life adversity, it will fundamentally alter hepatic gluconeogenesis, inducing hyperglycaemia, and hence crystalise the significant lifelong risk of developing either the metabolic syndrome, or type 2 diabetes. This gives a “Jekyll and Hyde” role to gluconeogenesis, providing the necessary energy in situations of acute stress, but driving towards pathophysiological consequences when the HPA axis has been altered.
REVIEW | doi:10.20944/preprints202202.0180.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: oxidative stress; nitrative stress; reactive oxygen species; reactive nitrogen species; nitric oxide inflammation; obesity; peroxynitrite; adipose tissue
Online: 30 September 2022 (11:10:38 CEST)
It is now well accepted that most chronic diseases have a common feature which is “low-grade” inflammation. Whether inflammation is causal or rather consequent to these diseases is still a matter of debate. A key factor of inflammation is considered to be “oxidative stress”, which is the result of an alteration of redox homeostasis which is critical for the regulation of physiological cell and organ metabolism and proliferation. The term “oxidative stress” is how-ever often used in an inappropriate manner as the primary target of the initial oxidative radical, superoxide ion, is nitric oxide which, being in large excess, acts as a “buffer”, yielding reactive nitrogen species. It is only once the superoxide fluxes exceed the nitric oxide fluxes that true “oxidative stress” occurs. Nitro-oxidative stress is a more appropriate term which takes into account the evolving generation of reactive nitrogen and oxygen species and their effects on cell and organ pathophysiology. The molecular bases of redox homeostasis and nitro-oxidative stress will be presented and discussed using obesity-linked inflammation as a path-ophysiological example.
REVIEW | doi:10.20944/preprints202110.0447.v1
Subject: Life Sciences, Biochemistry Keywords: UPR; IRE1; PERK; ATF6; lipid bilayer stress; ER stress; secretory pathway; hydrophobic mismatch; membrane thickness; membrane stiffness
Online: 29 October 2021 (07:57:29 CEST)
The endoplasmic reticulum (ER) is the major site of membrane biogenesis in most eukaryotic cells. As the entry point to the secretory pathway, it handles more than 10.000 different secretory and membrane proteins. The membrane insertion of proteins, their folding, and ER exit are affected by the lipid composition of the ER membrane and its collective membrane stiffness. The ER is also a hotspot of lipid metabolism for membrane lipids including sterols, glycerophospholipids, ceramides and neural storage lipids. The unfolded protein response (UPR) bears an evolutionary conserved, dual sensitivity to both protein folding-imbalances in the ER lumen and aberrant compositions of the ER membrane, referred to as lipid bilayer stress (LBS). Through transcriptional and non-transcriptional mechanisms, the UPR upregulates the protein folding capacity of the ER and balances the production of proteins and lipids to maintain a functional secretory pathway. In this review, we discuss how UPR transducers sense unfolded proteins and LBS with a particular focus on their role as guardians of the secretory pathway.
REVIEW | doi:10.20944/preprints202302.0063.v1
Subject: Life Sciences, Biotechnology Keywords: Microalgae; Bio acids; Phytohormones; Medium Culture; Stress
Online: 3 February 2023 (08:45:13 CET)
Natural astaxanthin is a precious substance obtained from some organisms such as microalgae. This plant has many benefits for humans, so research into its cost-effective and economical production has recently increased. For this purpose, some methods such as the use of different culture media, gene engineering, different stresses, nanoparticles, bio acids, and phytohormones are important. Accordingly, this review study was conducted to demonstrate the effect of the factors mentioned above for the high production of astaxanthin in microalgae, especially Haematococcus pluvialis (H.p).
ARTICLE | doi:10.20944/preprints202301.0373.v1
Subject: Life Sciences, Microbiology Keywords: alternative drugs; cryptococcosis; oxidative stress; synthetic peptides
Online: 20 January 2023 (15:17:15 CET)
Cryptococcus neoformans is a human multidrug-resistant yeast with high mortality rates in immunocompromised patients. Recently, the synthetic peptide Mo-CBP3-PepII emerged as a potent anticryptococcal molecule with an MIC50 at low concentration. Here, the mechanisms of action of Mo-CBP3-PepII were deeply analyzed to provide new information about how it led C. neoformans cells to death. Light and fluorescence microscopies, analysis of enzymatic activities, and proteomic analysis were employed to understand the effect of Mo-CBP3-PepII on C. neoformans cells. Light and fluorescence microscopies revealed Mo-CBP3-PepII induced the accumulation of anion superoxide and hydrogen peroxide in C. neoformans cells. In addition to a reduction in the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) in the cells treated with Mo-CBP3-PepII. In the presence of Ascorbic acid (AsA), no ROS were detected and Mo-CBP3-PepII lost the inhibitory activity against C. neoformans. Yet, Mo-CBP3-PepII inhibited the activity of lactate dehydrogenase (LDH), ergosterol biosynthesis, and induced the decoupling of cytochrome c from the mitochondrial membrane. Proteomic analysis revealed a reduction in the abundance of proteins related to energetic metabolism, DNA and RNA metabolism, pathogenicity, protein metabolism, cytoskeleton, and cell wall organization and division. Our findings indicated that Mo-CBP3-PepII might have multiple mechanisms of action against C. neoformans cells, mitigating the development of resistance and thus being a potent molecule to be employed in the production of new drugs against C. neoformans infections.
ARTICLE | doi:10.20944/preprints202301.0274.v1
Subject: Biology, Animal Sciences & Zoology Keywords: chrysoeriol; embryo development; porcine; oxidative stress; autophagy
Online: 16 January 2023 (07:54:26 CET)
Chrysoeriol (CHE) is a flavonoid substance that exists in many plants and has various physiological and pharmacological effects, including anti-inflammatory, antioxidant, anti-tumor, and protective activity, especially for the cardiovascular system and liver. This study aimed to analyze the results and possible mechanisms of CHE on early porcine embryo development. Adding CHE to the culture media can improve the development quality of early porcine embryos. CHE significantly increased the blastocyst rate and total cell number of embryos in vitro. The apoptosis of blastocyst in CHE-treated culture also decreased significantly compared with untreated culture. Furthermore, CHE downregulated intracellular reactive oxygen species (ROS) and increased glutathione (GSH) in embryos. CHE was also shown to improve the activity of mitochondria and inhibit the occurrence of autophagy. In addition, antioxidant-related genes (SOD1, SOD2, and CAT) and cell pluripotency-related genes (SOX2, OCT4, and NANOG) were upregulated, while those related to apoptosis (Caspase 3) and autophagy (LC3B) showed a downward trend after supplementation with CHE. These results indicated that CHE improved the development of porcine embryos in vitro by reducing oxidative stress and autophagy levels.
ARTICLE | doi:10.20944/preprints202210.0300.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: Nrf2; Oxidative stress; Antioxidants; Pentylenetetrazol; Epilepsy; Seizure
Online: 20 October 2022 (08:29:58 CEST)
The modulation of Nrf2 activity has been reported to be implicated in the pathology of various neurological disorders, including epilepsy. Previous studies have demonstrated that Nrf2 is activated in the post-status epilepticus rat model, however, the spatio-temporal, as well as cell type-specific expression of Nrf2 following brief epileptic seizures remains unclear. Here, we evaluated how an acute epileptic seizure affected the expression of Nrf2 and its downstream genes in the cortex and the hippocampus up to 1-week following the induced seizure. We found that after a pentylenetetrazol-induced seizure, Nrf2 significantly increased at 24 h at the mRNA level and 3 to 6 h at the protein level in the cortex. In the hippocampus, the Nrf2 mRNA level peaked at 3 h after the seizure, and no significant changes were observed in the protein level. Interestingly, the mRNA level of Nrf2 downstream genes peaked at 3-6 h after seizure in both the cortex and the hippocampus. A significant increase in the expression of Nrf2 was observed in the neuronal population of CA1 and CA3 regions of the hippocampus, as well as in the cortex. Moreover, we observed no change in the co-localization of Nrf2 with astrocytes neither in the cortex nor in CA1 and CA3. Our results revealed that following a brief acute epileptic seizure, the expression of Nrf2 and its downstream genes is transiently increased and peaked at early timepoints after seizure predominantly in the hippocampus, and this expression is restricted to the neuronal population.
ARTICLE | doi:10.20944/preprints202210.0195.v2
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Warburg effect, oxidative stress, magnesuria, inflammasome, butyrate
Online: 14 October 2022 (12:56:34 CEST)
Long Covid has many symptoms that overlap with ME(myalgic encephalomyelitis)/CFS(chronic fatigue syndrome), FM(fibromyalgia), EBV(Epstein-Barr virus), CMV(cytomegalovirus), CIRS (chronic inflammatory response syndrome), MCAS(mast cell activation syndrome), POTS(postural orthostatic tachycardia syndrome), and post viral fatigue syndrome. They all portend a “long haul” with an antioxidant shortfall and elevated Ca:Mg. Oxidative stress is the root cause. Linkage between TGF(transforming growth factor)-β, IFN(interferon)-γ, the RAS(renin angiotensin system), and the KKS(kallikrein kinin system) is discussed. Technical explanations for the renin aldosterone paradox in POTS, the betrayal of TGF-β, and the commonality of markers for the Warburg effect are offered. The etiology of the common Long Covid symptoms of post exertional malaise, fatigue, and brain fog as well as anosmia, hair loss, and GI symptoms is technically discussed. Ca:Mg is critical to the glutamate/GABA balance. The role of GABA and butyrates from the “good” intestinal bacteria in the gut-brain axis and its correlation with chronic fatigue diseases are explored. The crosstalk between the ENS(enteric nervous system) and the ANS(autonomic nervous system) and the role of the vagus in both are emphasized. HRV(heart rate variability), the fifth vital sign, points to an expanded gut-brain-heart/lung axis. A suggested approach to all of these - Long Covid, chronic fatigue diseases, post viral fatigue syndrome, and general health - is presented.
ARTICLE | doi:10.20944/preprints202209.0437.v1
Subject: Biology, Other Keywords: Semen; hesperidin; cryopreservation; oxidative stress; antioxidant; ram
Online: 28 September 2022 (09:35:03 CEST)
We conducted this study to determine the potential cryopreservative effects of different hesperidin (vitamin P; HSP) doses on ram semen after freeze-thawing. Semen samples were obtained from Sönmez rams by an artificial vagina. The samples were divided into six groups: control, 10, 50, 100, 250, and 500 µg/mL HSP (C, HSP10, HSP50, HSP100, HSP250, and HSP500, respectively). At the end of the study, sperm motility and kinetic parameters, plasma membrane acrosome integrity (PMAI), high mitochondrial membrane potential (HMMP), viability, lipid peroxidation levels (LPL), chromatin damage, oxidant parameters, and antioxidant parameters were assayed. None of the doses of HSP added to the semen extender showed any enhancing effect on progressive motility compared to C (p>0.05). In fact, HSP500 had negative effects (p<0.05). Moreover, PMI activities were the highest at the HSP10 dose, while LPL values were the lowest (p<0.05). The doses of HSP10 and HSP50 added to the Tris extender medium showed positive effects on spermatozoon chromatin damage. Consequently, we can say that HSP doses used in this study are not effective on semen progressive motility, but the HSP10 dose is effective on PMAI and chromatin damage by reducing LPL.
ARTICLE | doi:10.20944/preprints202209.0066.v1
Online: 5 September 2022 (13:44:44 CEST)
Silicon is an essential trace nutrient for plant growth and is frequently employed to remediate soils contaminated with heavy metals in agriculture. However, silicon’s role and mechanism in reducing heavy metal toxicity have not been well understood, especially for multi-heavy metals. In this study, the effects of silicon-rich materials (silicate, rice husk biochar (RHB), and bentonite) on growth trait, antioxidant response, and heavy metal accumulation and distribution of wheat grown in two soils polluted by multiple heavy metals (Cd, Zn, Pb, and As) were investigated. The results revealed that the addition of silicon-rich materials enhanced plant growth, improved the photosynthetic attributes in leaf tissues, and decreased the contents of Cd, Zn, Pb, and As in wheat shoots and grains. The examination of the subcellular distribution of heavy metals in plants implied that silicon-rich materials transferred heavy metals as intracellular soluble fractions to the cell walls, indicating the reduction of mobility and toxicity of heavy metals in the plants. In addition, the application of the silicon-rich materials reduced oxidative damage in plants by downregulating plant antioxidant response systems and decreasing the production of malondialdehyde (MDA), ascorbic acid (AsA), and glutathione (GSH). Moreover, fractionation analysis of soil heavy metals showed that silicon-rich amendments could convert bioavailable heavy metals into immobilized forms. The results indicated that silicon-rich materials could remediate multi-heavy metal-polluted soils and promote wheat production.
ARTICLE | doi:10.20944/preprints202208.0485.v1
Subject: Biology, Ecology Keywords: Arsenic; global warming; invertebrates; behavior; oxidative stress
Online: 29 August 2022 (10:43:42 CEST)
Contamination with Arsenic, a toxic metalloid, is increasing in the marine environment. Additionally, global warming can alter metalloids toxicity. Polychaetes are key species in marine environments. By mobilizing sediments, they play vital roles in nutrient and element (including contaminants) cycles. Most studies with marine invertebrates focused on the effects of metalloids on either adults or larvae. Here we bring information on the effects of temperature increase and arsenic contamination on the polychaete Hediste diversicolor in different growth stages and water temperatures. Feeding activity and biochemical responses – neurotransmission, indicators of cell damage, antioxidant and biotransformation enzymes and metabolic capacity - were evaluated. Temperature rise combined with As imposed alterations on feeding activity and biochemical endpoints at different growth stages. Small organisms have their antioxidant enzymes increased, avoiding lipid damage. However, larger organisms are the most affected class due to inhibition of superoxide dismutase, which resulted in protein damage. Oxidative damage was observed on smaller and larger organisms exposed to As and 21 °C, demonstrating higher sensibility to the combination of temperature rise and As. The observed alterations may have ecological consequences, affecting the cycle of nutrients, sediment oxygenation and the food chain that depend on the bioturbation of this polychaete.
ARTICLE | doi:10.20944/preprints202207.0311.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: glucose; cortisol; corticosterone; stress; early life adversity
Online: 21 July 2022 (07:53:13 CEST)
External stressors strongly increase cardiovascular activity and induce metabolic changes that ensure the availability of glucose and oxygen as part of a co-ordinated stress response. Exposure to stress during early life appears to have an exaggerated long-term effect on this response, leading to an increased risk or cardiometabolic disorders. Here we demonstrate that acute stress induced glucose release is impacted by the early life environment in rodent maternal deprivation and early-life infection models and this was validated in our EpiPath human early-life adversity cohort. In all three models differences in baseline blood glucose levels after ELA exposure were sex dependent. The human ELA model showed higher levels of basal glucose in females, similar to the mouse infection and rat maternal deprivation models. We anticipated that the stress induced glucose rise would be a GC dependent process. However, the kinetics of stress-induced glucose release, peaking 15-28 minutes before cortisol suggest that it is a GC-independent process. We confirmed this by administering an escalating dose of cortisol to a health human cohort, and the inability of an intravenous GC bolus induce a glucose rise in man confirms that it is a rapid, GC independent, process.In conclusion, we provide a novel perspective on the mechanisms behind stress related metabolic changes and highlights the importance of collecting early life data as a measure to understand an individual’s metabolic status in a better light.
SHORT NOTE | doi:10.20944/preprints202206.0044.v1
Subject: Biology, Anatomy & Morphology Keywords: drill; gorilla; mandrill; nonhuman primates; papio; stress
Online: 3 June 2022 (10:22:01 CEST)
The aim of this study was to compare left and right osseous orbit forms in two different Catarrhini primate genera using geometric morphometric techniques. The analysis was carried out on 20 well-preserved skulls from gorilla (Gorilla gorilla, n=10) and papios (drill [Mandrillus leucophaeus, n=3] and mandrill [M. sphinx, n=7]) from animals kept in zoo, which were photographed in their frontal norm. A set of 4 sagittal landmarks on the face and 23 semilandmarks on each orbita contour were used. According to results, right and left orbitas were similar in size but not in shape, appearing to be significative for individual-by-side interaction (fluctuating asymmetry). It is supposed this due to a developmental instability due to captivity life. Fluctuating asymmetry was clearly higher among gorillas, seeming logical that hominoidea primates suffering in captivity is higher than among cercopithecids (papios and mandrills). Side directional differences were significative only for papios. We supposed it to be due to a stronger stroke of lateralized mastication as, compared to gorillas, mandibles in papios are longer.
ARTICLE | doi:10.20944/preprints202204.0269.v1
Subject: Biology, Ecology Keywords: Antarctic strain; copper stress; adaption responses; metabolomics
Online: 28 April 2022 (03:59:23 CEST)
Copper toxicity has been a selective pressure on the sea-ice bacteria due to its widespread occur-rence in Antarctica. Here, with a combined biochemical and metabolomic approach, the Cu2+ ad-aptation mechanisms of Antarctic bacteria were analyzed. Heavy metal resistance pattern of Pb2+ > Cu2+ > Cd2+ > Hg2+ > Zn2+ was observed. Copper treatment did increase the activity of antioxidants and enzymes, maintaining cellular redox state balance and normal cell division and growth. Metabolomics analysis demonstrated that fatty acids, amino acids, and carbohydrates played dominant roles in copper stress adaptation. The results indicated that the adaptation mechanisms of strain O5 to copper stress included protein synthesis and repair, accumulation of organic per-meable substances, up-regulation of energy metabolism, and formation of fatty acids. This study increases the resistance mechanism understanding of Antarctic strains to heavy metals in extreme environments.
ARTICLE | doi:10.20944/preprints202203.0174.v1
Subject: Biology, Plant Sciences Keywords: halophyte; rhizobacteria; PGPR; root inoculation; osmotic stress
Online: 14 March 2022 (06:53:44 CET)
Rhizosphere bacteria have a decisive influence on plant ionic adjustment, as well as in ameliorating plant growth under an array of stress situations. Plant growth-promoting rhizobacteria (PGPR) colonize the rhizosphere of plants and promote plant growth through mechanisms such as solubilization of mineral phosphates, biological N2 fixation, production of siderophores and phytohormones, and can induce systemic resistance in the plant. This can be of extreme importance when considering the restoration of salinized grounds by halophytic species. This present work aims to evaluate the physiological fitness and phytoprotection improvement by salt marsh PGPR in Halimione portulacoides under mild and severe salt stress. Plants inoculated with PGPR-consortium showed higher photochemical performances, improved antioxidant response, and promotion of osmotic balance traits, that boosted the individual’s ability to cope with mild salt stress. All these changes are also in line with the differential elemental profiles (Na, K, and Ca) observed in the different plant tissues. Even under severe salt stress, some physiological traits were improved when compared to the non-inoculated individuals. The results developed under this work, point out an important role of bioaugmentation in promoting plant fitness and improving salt tolerance, with a great potential for applications in seawater agriculture, restoration, and bio-reclamation of salinized soils.
REVIEW | doi:10.20944/preprints202202.0014.v1
Online: 1 February 2022 (12:53:40 CET)
Each year, the global population and agriculture suffer critical agricultural output losses as a result of severe drought devastation. Physiological drought occurs when plants are unable to extract water from the soil, even though it is available in the root zone. Apart from having a significant effect on plant physiology, drought stress has the effect of reducing crop yield. Drought stress influences plant metabolism both directly and indirectly. Drought stress alters the morpho-anatomical, physiological, and biochemical composition of plants, thereby decreasing transpiration water loss and increasing the efficiency with which plants use their water. Constant water loss through transpiration, combined with previously lost water, results in leaf water deficits. Nonetheless, drought stress has a wide variety of effects, ranging from lesions to confusion. Plant health is harmed when their ability to absorb water and nutrients, interact with their environment, and breathe is harmed. Apart from oxidative damage to plants, it may also result in cell death, which can occur under certain conditions when cells are exposed to their environment. Drought induces a plethora of physiological and molecular changes in plants, the majority of which assist them in adapting to the harsh environment. To mitigate drought's adverse effects, we must first gain a better understanding of how drought affects plant physiology. The purpose of this research is to better understand how drought affects plant development by examining the causes and effects of drought stress.
ARTICLE | doi:10.20944/preprints202201.0339.v1
Subject: Biology, Ecology Keywords: abiotic stress; proteomic; rehabilitating minelands; rhizosphere; symbiosis
Online: 24 January 2022 (10:07:29 CET)
Dioclea apurensis Kunth is native to ferruginous rocky outcrops (known as canga) in the eastern Amazon. Native cangas are considered hotspots of biological diversity and have one of the largest iron ore deposits in the world. There, D. apurensis can grow in post-mining areas where molecular mechanisms and rhizospheric interactions with soil microorganisms are expected to contribute to their establishment in rehabilitating minelands. In this study, we compare the root proteomic profile and rhizosphere-associated bacterial and fungal communities of D. apurensis growing in canga and a rehabilitating mineland to characterize the main mechanisms that allow the growth and establishment in post-mining areas. The results showed that proteins involved in response to oxidative stress, drought, excess of iron, and phosphorus deficiency were more accumulated in canga and, therefore, helped explain its high establishment rates in rehabilitating minelands. Rhizospheric selectivity of microorganisms was more evident in canga. The microbial community structure was mostly different between the two habitats, denoting that despite having its preferences, D. apurensis can associate with beneficial soil microorganisms without specificity. Therefore, its good performance in rehabilitating minelands can also be improved or attributed to its ability to cope with beneficial soil-borne microorganisms. Native plants with such adaptations must be used to enhance the rehabilitation process.
ARTICLE | doi:10.20944/preprints202111.0003.v2
Subject: Earth Sciences, Oceanography Keywords: Scatterometer; wind stress; surface currents; Indian Ocean
Online: 31 December 2021 (14:50:47 CET)
This study examines the effect of surface currents on the bulk algorithm calculation of wind stress estimated using the scatterometer data during 2007-2020 in the Indian Ocean. In the study region as a whole the wind stress decreased by 5.4% by including currents into the wind stress equation. The most significant reduction in the wind stress is found along the most energetic regions with strong currents such as Somali Current, Equatorial Jets and Aghulhas retroflection. A highest reduction of 11.5% is observed along the equator where the Equatorial Jets prevail. A sensitivity analysis has been carried out for the study region and for different seasons to assess the relative impact of winds and currents in the estimation of wind stress by changing the winds while keeping the currents constants and vice versa. The inclusion of currents decreased the wind stress and this decrease is prominent when the currents are stronger. This study showed that equatorial Indian Ocean is the most sensitive region where the current can impact on wind stress estimation. The results showed that uncertainties in the wind stress estimations are quite large at regional levels and hence better representation of wind stress incorporating ocean currents should be considered in the ocean/climatic models for accurate air-sea interaction studies.
ARTICLE | doi:10.20944/preprints202112.0161.v1
Online: 9 December 2021 (15:46:41 CET)
Cells that experience high levels of oxidative stress respond with the induction of antioxidant proteins through the activation of the transcription factor Nrf2. Nrf2 is negatively regulated by Keap1 which binds to Nrf2 to facilitate its ubiquitination and ensuing proteasomal degradation under basal conditions. Here, we study protein folding and misfolding in Nrf2 and Keap1 in yeast, mammalian cells, and purified proteins under oxidative stress conditions. Both Nrf2 and Keap1 are susceptible to protein misfolding and inclusion formation upon oxidative stress. We propose that the intrinsically disordered regions within Nrf2 and the high cysteine content of Keap1 contribute to their oxidation and the ensuing misfolding. Our work reveals previously unexplored aspects of Nrf2 and Keap1 regulation and dysregulation by oxidation-induced protein misfolding.
ARTICLE | doi:10.20944/preprints202111.0094.v1
Subject: Biology, Animal Sciences & Zoology Keywords: Sparus aurata; social stress; hierarchy; cortisol; phagocytosis
Online: 4 November 2021 (08:44:54 CET)
Abstract: Social stress can affect the ability of the fish to respond to various stressors, such as pathogens or environmental variations. In this paper, the effects of social stress on gilt-head bream (Sparus aurata) were investigated. To study the effects of physiological stress, we evaluated biochemical and cellular parameters as cortisol, glucose, lactate, osmolarity and phagocytosis 24 hours after the establishment of social hierarchy. Social hierarchy was determined and characterised by behavioural observation (aggressive acts and feeding order) of the specimens (dominant “α”, subordinate “β” and “γ”). After the establishment of the social hierarchy, we observed that the levels of plasma cortisol and other biochemical stress markers (glucose and lactate) were higher in subordinate individuals than in dominant ones. In addition, the modulation of phagocytic activity of the peritoneal cavity cells (PEC) demonstrated that social stress appeared to affect the immune response. At last, principal component analysis clearly separated the subordinate fish groups from the dominant groups based on stress markers and phagocytic activity of the peritoneal exudates cells.