REVIEW | doi:10.20944/preprints202210.0065.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: preeclampsia; neonatal outcome; vitamin D; 25(OH)D, 1,25(OH)2D; diabetes; pregnancy complication; vitamin D deficiency; vitamin D supplementation
Online: 6 October 2022 (12:16:11 CEST)
Vitamin D plays an essential role in embryogenesis and the course of intra- and postnatal periods and is crucially involved in the functioning of the mother-placenta-fetus system. Low quantity of Vitamin D during pregnancy can lead to the elevated risk for preeclampsia occurence. Despite the numerous studies on the association of Vitamin D deficiency and preeclampsia development, the current research on this theme is contradictory. In this review we summarize and analyze study data on the effects of vitamin D deficiency and supplementation on pregnancy, labor, fetal and neonatal outcomes.
ARTICLE | doi:10.20944/preprints202209.0481.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: diabetes status; prediabetes; type 2 diabetes; breast cancer; NHANES
Online: 30 September 2022 (08:40:03 CEST)
Abstract Objectives: The purpose of this study was to determine whether breast cancer and diabetes status are related in adult Americans. Methods: We conducted a cross-sectional study of 7,599 individuals from the National Health and Nutrition Examination Survey (NHANES). Diabetes was classified as type 2 diabetes and pre-diabetes. Both prediabetes and diabetes were diagnosed according to ADA 2014 guidelines. Multiple logistic regression analysis was used to explore the relationship between diabetes status and breast cancer. Results: We found that prediabetes (OR = 0. 60, 95% CI:(0. 40, 0. 88), P= 0. 009613) and non-diabetes (OR = 0.05.3,95% CI: (0.34, 0.83), P = 0. 006014) were associated with a reduced risk of breast cancer in comparison to Type 2 diabetes (literature). Prediabetes in non-Hispanic blacks was associated with a reduced risk of breast cancer (OR=0. 55,95%CI:0. 40-0. 75, P<0. 001). Using two segmented linear regression models to fit the relationship between BMI and breast cancer, we found that the relationship between BMI and breast cancer was nonlinear, but there was a threshold effect. The threshold effect analysis found that BMI affcted breast cancer at an inflection point 26. 3 Kg/m2. Adjusted OR (95% CI) on both sides of the turning point was 1. 0799 ( 1. 0029, 1. 1629 ) and 0. 9873 ( 0. 9638, 1. 0115 ), respectively. Conclusions: Diabetes status is associated with the risk of breast cancer development. Moreover, the risk of developing breast cancer steadily increased from nondiabetes to prediabetes and type 2 diabetes. In addition, the prevalence of breast cancer showed a gradual increase withincreasing BMI up to 26. 3 Kg/m2 with the highest prevalence of breast cancer. There was an inverse U-shaped relationship between BMI and the breast cancer prevalence.
ARTICLE | doi:10.20944/preprints202209.0180.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: endometriosis; multi-omics; expression profile; menstrual blood; MenSCs
Online: 13 September 2022 (12:32:56 CEST)
Given the importance of menstrual blood in the pathogenesis of endometriosis and the multifunctional roles of menstrual mesenchymal stem cells (MenSCs) in regenerative medicine, this issue has gained prominence in the scientific community. Moreover, recent reviews highlight how robust the integrated assessment of omics data is for endometriosis. To our knowledge, no study has applied the multi-omics approaches to endometriosis MenSCs. It is a case-control study at a university-affiliated hospital. MenSCs transcriptome and proteome data were obtained by RNA-seq and UHPLC-MS/MS detection. Among the differentially expressed proteins and genes, we emphasize ATF3, ID1, ID3, FOSB, SNAI1, NR4A1, EGR1, LAMC3, and ZFP36 genes and MT2A, TYMP, COL1A1, COL6A2, and NID2 proteins that were already reported in the endometriosis. Our functional enrichment analysis reveals integrated modulating signaling pathways such as epithelial-mesenchymal transition (↑) and PI3K signaling via AKT to mTORC1 (↓in proteome), mTORC1 signaling, TGF beta signaling, TNFA signaling via NFkB, and response to hypoxia via HIF1A targets (↑in transcriptome). Our findings highlight primary changes in the endometriosis MenSCs, suggesting that the chronic inflammatory endometrial microenvironment can modulate these cells, providing opportunities for endometriosis etiopathogenesis. Moreover, they identify challenges for future research leveraging knowledge for regenerative and precision medicine in endometriosis.
ARTICLE | doi:10.20944/preprints202208.0317.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Cytochrome P450; POR; Congenital adrenal hyperplasia; metabolic disorders; CYP3A4; protein stability; drug metabolism
Online: 17 August 2022 (10:02:51 CEST)
Cytochrome P450 oxidoreductase (POR) is the redox partner of steroid and drug-metabolizing cytochromes P450 located in the endoplasmic reticulum. Mutations in POR cause a broad range of metabolic disorders. The POR variant rs17853284 (P228L) identified by genome sequencing has been linked to lower testosterone levels and reduced P450 activities. We expressed POR wild type and the P228L variant in bacteria, purified the proteins, and performed protein stability and catalytic functional studies. Variant P228L affected the stability of the protein as evidenced by lower unfolding temperatures and higher sensitivity to urea denaturation. A significant reduction of small molecule metabolism was observed with POR P228L while activities of CYP3A4 were reduced by 25%, and activities of CYP3A5, and CYP2C9 were reduced by more than 40% compared to WT POR. The 17,20 lyase activity of CYP17A1 responsible for production of main androgen precursor dehydroepiandrosterone, was reduced to 27% of WT in presence of P228L variant of POR. Based on in silico and in vitro studies we predict that the change of proline to leucine may change the rigidity of the protein, causing conformational changes in POR, leading to altered electron transfer to redox partners. A single amino acid change can affect protein stability and cause a severe reduction in POR activity. Molecular characterization of individual POR mutations is crucial for a better understanding of the impact on different redox partners of POR.
ARTICLE | doi:10.20944/preprints202208.0159.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolomics; NMR; PEMT; knockout; aging; mice; liver; intestine; white/brown adipose tissue
Online: 8 August 2022 (13:36:04 CEST)
Phospholipid metabolism, including phosphatidylcholine (PC) biosynthesis, is crucial for various biological functions and is associated to longevity. Phosphatidylethanolamine N-methyltransferase (PEMT) is a protein that catalyzes the biosynthesis of PC, the levels of which change in various organs such as brain and kidney during aging. However, the role of PEMT for systemic PC supply is not fully understood. To address how PEMT affects aging-associated energy metabolism in tissues responsible for nutrient absorption, lipid storage and energy consumption, we employed NMR-based metabolomics to study liver, plasma, intestine (duodenum, jejunum, ileum), brown/white adipose tissues (BAT, WAT), and skeletal muscle of young (9–10 weeks) and old (96–104 weeks) wild-type (WT) and PEMT knockout (KO) mice. We found that the effect of PEMT-knockout was tissue-specific and age-dependent. Deficiency of PEMT affected the metabolome of all tissues examined, among which the metabolome of BAT from both young and aged KO mice was dramatically changed in comparison to WT mice, whereas the metabolome of jejunum was only slightly affected. As for aging, the absence of PEMT increased the divergence of metabolome during aging of liver, WAT, duodenum and ileum and decreased the impact on skeletal muscle. Overall, our results suggest that PEMT plays a previously unexplored critical role in both aging and energy metabolism.
ARTICLE | doi:10.20944/preprints202208.0073.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: extravillous trophoblast; placenta; saturated fatty acid; in-utero environment; MRP1
Online: 3 August 2022 (04:21:58 CEST)
Normal function of placental extravillous trophoblasts (EVTs), which are responsible for uteroplacental vascular remodeling, is critical for adequate delivery of oxygen and nutrients to the developing fetus and normal fetal programming. Proliferation and invasion of spiral arteries by EVTs depends upon adequate levels of folate. Multidrug resistance-associated protein 1 (MRP1), which is an efflux transporter, is known to remove folate from these cells. We hypothesized that palmitic acid increases MRP1-mediated folate removal from EVTs, thereby interfering with EVTs’ role in early placental vascular remodeling. HTR-8/SVneo and Swan-71 cells, first trimester human EVTs, were grown in the absence or presence of 0.5 mM and 0.7 mM palmitic acid, respectively, for 72 h. Palmitic acid increased ABCC1 gene expression and MRP1 protein expression in both cell lines. The rate of folate efflux from the cells into the media increased with a decrease in migration and invasion functions in the cultured cells. Treatment with N-acetyl cysteine (NAC) prevented the palmitic acid mediated upregulation of MRP1 and restored invasion and migration in the EVTs. Finally, in an ABCC1 knockout subline of Swan-71 cells, there was a significant increase in invasion and migration functions. The novel finding in this study that palmitic acid increases MRP1-mediated folate efflux provides a missing link that helps to explain how maternal consumption of saturated fatty acids compromises the in-utero environment.
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.
ARTICLE | doi:10.20944/preprints202207.0275.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: blood pressure; cardiorespiratory fitness; waist circumference; lifestyle intervention; primary care; adverse responders; metabolic syndrome
Online: 20 July 2022 (05:59:58 CEST)
Systemic hypertension has been recognized as a modifiable traditional cardiovascular risk factor and influenced by many factors such as eating habits, physical activity, diabetes and obesity. The objective of this study was to identify cardiometabolic factors that predict changes in blood pressure induced by a one-year lifestyle intervention in primary care settings involving a collaboration between family physicians, dietitians, and exercise specialists. Patients with metabolic syndrome diagnosis were recruited by family physicians participating in primary care lifestyle intervention among several family care clinics across Canada. Participants for whom all cardiometabolic data at the beginning (T0) and the end (T12) of the intervention were available were included in the present analysis (n=101). Patients visited the dietitian and the exercise specialist weekly for the first three months and monthly for the last nine months. Diet quality, exercise capacity, anthropometric indicators, and cardiometabolic variables were evaluated at T0 and at T12. The intervention induced a significant decrease in waist circumference (WC), systolic (SBP) and diastolic (DBP) blood pressure, and plasma triglycerides and an increase in cardiorespiratory fitness (estimated VO2max). Body weight (p<0.001), body mass index (BMI) (p<0.001), and plasma glucose (p=0.006) reduction and VO2max increase (p=0.048) were all related to changes in SBP. WC was the only variable for which changes were significantly correlated with those in both SBP (p<0.0001) and DBP (p=0.0004). Variations in DBP were not associated with changes in other cardiometabolic variables to a statistically significant extent. Twelve participants were identified as adverse responders in both SBP and DBP and displayed less favorable changes in WC. The beneficial effects of a lifestyle intervention on blood pressure were significantly associated with cardiometabolic variables, especially WC. These findings suggest that a structured lifestyle intervention in primary care can help improve cardiometabolic risk factors in patients with metabolic syndrome.
ARTICLE | doi:10.20944/preprints202207.0081.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: adolescents; high sensitivity C-reactive protein; Interleukin 6; Leucine-rich α-2 glycoprotein 1; obesity; TNF-α
Online: 6 July 2022 (03:25:10 CEST)
Leucine-rich α-2 glycoprotein1 (LRG1) is a member of the leucine-rich repeat (LRR) family that was implicated in multiple diseases including cancer, aging and heart failure as well as diabetes and obesity. LRG1 plays a key role in diet-induced hepatosteatosis and insulin resistance by mediating the crosstalk between adipocytes and hepatocytes. LRG1 also promotes hepatosteatosis by upregulating de novo lipogenesis in the liver and suppressing fatty acid β oxidation. In this study, we investigated the association of LRG1 with obesity markers including leptin and other adipokines in adolescents (11-14 years; n=425). BMI-for-age classification based on WHO growth charts was used to define obesity. Plasma LRG1 was measured by ELISA while other markers were measured by multiplexing assay. Median (IQR) of LRG1 levels was higher in obese [30 (25, 38) µg/mL] and overweight [30 (24, 39) µg/mL] adolescents, compared to normal-weight participants [27 (22, 35) µg/mL]. The highest tertile of LRG1 had an OR [95%CI] of 2.55 [1.44, 4.53] for obesity. LRG1 was positively correlated to plasma levels of HsCRP (R=0.2), Leptin (R=0.2) and Chemerin (R=0.24) with p<0.001. Additionally, it was positively associated with plasma level of IL6 (R=0.17) and IL10 (R=0.14) but not TNF-α. In conclusion, LRG1 levels are increased in obese kids and associate with increased levels of adipogenic markers. These results suggest the usefulness of LRG1 as an early biomarker for obesity and its related pathologies in adolescents.
ARTICLE | doi:10.20944/preprints202206.0129.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Diabetic retinopathy; Oxidative stress; Advanced glycation end products (AGEs); Antioxidant enzymes; Vascular endothelial growth factor; B-vitamins; Vitamin-C; Vitamin- E
Online: 8 June 2022 (12:40:07 CEST)
Excessive intracellular glucose in insulin independent tissues including nerve, nephron, lens and retina invites mishandling of metabolism of glucose resulting in a background of increased oxidative stress, advanced glycation end products (AGE) formation, lipid peroxidation and failure of antioxidant defense systems in type 2 diabetes mellitus (T2DM). All these detrimental biochemical anomalies ultimately attack biological membranes and especially capillary beds of retina and glomerulus of kidney, resulting in break-down of inner blood-retinal i.e. initiation of diabetic retinopathy (DR). If these disarrays are corrected to a large extent, development of DR can be avoided or delayed. In this prospective clinical trial, 185 patients with T2DM who received B-vitamins, vitamin-C, and E along with anti-diabetic medication for five years, demonstrated a slower rate of the development of DR and reduced abnormal biochemical mediators like reactive oxygen species (ROS), malondialdehyde (MDA), AGE, and vascular endothelial growth factor (VEGF) compared to 175 T2DM individuals who were treated with only anti-hyperglycemic drugs.
ARTICLE | doi:10.20944/preprints202206.0085.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Ranolozine; Insuline; astrocytes; inflammation; antioxidants
Online: 6 June 2022 (10:14:05 CEST)
Ranolazine (Rn) is a drug used to treat persistent chronic coronary ischemia. It has also been shown to have therapeutic benefits on the central nervous system and an anti-diabetic effect by lowering blood glucose levels and however, no effects of Rn on cellular sensitivity to insulin (Ins) have been demonstrated yet. The present study aimed to investigate the permissive effects of Rn on the actions of Ins in astrocytes in primary culture. Ins at 10-8 M, Rn (10-6 M) and Ins+Rn (10-8 M and 10−6 M respectively) were added to astrocytes during 24 h. In comparison to control cells, Rn and/or Ins caused modifications in cell viability and proliferation. p-AKT, p-ERK, p-eNOS, Mn-SOD, COX-2, and the anti-inflammatory protein COX-2 were all upregulated by ins. On the contrary, no significant changes were found in the protein expression of Cu/Zn-SOD, NF-κB and IκB. The presence of Rn produced an increase in p-ERK protein and a significant decrease in COX-2 protein expression. Furthermore, Rn significantly increased the effects of Ins on the expression of p-AKT, p-eNOS, p-ERK, Mn-SOD, and PPAR-γ. On the other hand, Rn+Ins produced a significant decrease in COX-2 expression. In conclusion, Rn facilitated the effects of insulin on the p-AKT, p-eNOS, p-ERK, Mn-SOD and PPAR-γ, signaling pathways, as well as on the anti-inflammatory and antioxidant effects of the hormone.
ARTICLE | doi:10.20944/preprints202204.0052.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Carbohydrates; keto diet; IRS; C-peptide
Online: 7 April 2022 (04:03:54 CEST)
Abstract: Carbohydrates form the major source of energy in Asian diets. A lower carbohydrate diet became the recommended golden standard for healthy lifestyle. However, the effects of low-carbohydrates diet on health in apparently healthy individuals have been poorly studied, especially in relation to insulin resistance syndrome (IRS). A total of 120 healthy weight participants with no previous history of a major medical condition and an average BMI of ≤ 25kg/m2 were recruited. Self-reported dietary intake and objective physical activity by accelerometry were tracked for seven days. Participants were divided into three categories according to their dietary intake of carbohydrates. Blood samples were collected for metabolic markers analysis. HOMA of insulin resistance (HOMA-IR), β-cell function (HOMA-B) and C-peptide were used to evaluate glucose homeostasis. The consumption of low carbohydrates (less than 45% of total energy) significantly correlated with higher HOMA-IR, Lower HOMA-β % compared to moderate carbohydrate intake (between 45% to 65%). However, only the HOMA-β % was significantly influenced by carbohydrates intake. Moreover, low carbohydrates intake was significantly associated with elevated C-peptide secretion. The substitution of carbohydrates with other macronutrients, such as fat and proteins in the Atkins/ketogenic diet, resulted in a pronounced induction of IRS-related inflammatory markers; FGF2, IP-10, IL-6, IL-17A, MDC and reduction of IL-13. Overall, the presented data highlight, for the first time, that low carbohydrate intake results in significant glucose homeostasis imbalance that may be driven by a heightened state of inflammatory response.
REVIEW | doi:10.20944/preprints202202.0353.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Diabetic; Chronic Kidney Disease; Metformin; Acidosis Lactate
Online: 28 February 2022 (09:28:33 CET)
Background: Diabetes Mellitus is a metabolite disorder with parameters of high blood sugar levels. In the management of diabetes can be used the drug metformin is the gold of choice to achieve a therapeutic effect and rarely causes side effects of the drug, but it still has debate view. However, if used in excessive doses for patients with kidney disease, it will be contraindicated with side effects such as lactic acidosis. Objective: This study aims to evaluate the side effect of Metformin for diabetic kidney diseases (DKD) patients. Method: This study used the Narrative Review Method that was obtained from 2011 to 2021, in the English language from PubMed, Google Scholar, and Cochrane Library. Results: Metformin is at the forefront of the treatment of type 2 diabetes mellitus (DM2). Metformin is likely to have lactic acidosis-related adverse effects in chronic kidney disease (CKD) patients, such as increased arterial lactate. Lactic acidosis is defined as an increase in arterial lactate with an indicator of more than five mmol/L and an arterial blood pH of less than 7.35. Metformin-induced lactate levels are considered to be below the parameters. DKD risk factors can be conceptually classified as several susceptibility factors, initiation factors, and developmental factors. The two most prominent risk factors are hyperglycemia and hypertension. Conclusion: Metformin can increase lactate levels in CKD patients but is still below the parameters of lactic acidosis. This study may have some weaknesses and requires further prospective research to validate the results.
ARTICLE | doi:10.20944/preprints202202.0097.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Captive breeding; endangered; red panda; reproductive hormone; stress hormone; welfare
Online: 7 February 2022 (16:07:29 CET)
Animals in human care are affected by stressors that can ultimately reduce fitness. When reproduction is affected, endangered species’ conservation programmes can be severely compromised. Thus, understanding factors related to stress and reproduction, and measures of related hormones, are important to ensure captive breeding success. Red pandas are endangered and populations in the wild are threatened with extinction. A global captive breeding programme has been launched to conserve the species with the goal of reintroduction. However there is little informaiton on how stressors impact reproductive aspects of the species. This study measured fecal glucocorticoid (fGCM), fecal progestagen (fPM) and fecal androgen (fAM) metabolite concentrations in 12 female and 8 male red pandas (Ailurus fulgens fulgens) at three zoos in northeastern India to determine predictors of adrenal and gonadal steroid activity and the influence of fGCM on reproduction. Results indicated that fGCM concentrations were higher in males than females, and positively correlated with number of visitors, while negatively related to frequency of feedings and enclosure area. Sex, visitor number, frequency of feeding, and enclosure area explained 67% of the variations in fGCM concentrations in the study population. Concentrations of fPM were positively associated with tree density in the enclosure, explaining 47% of the variation among females. For fAM, positive associations were found with frequency of feeding, but concentrations were negatively related to age and number of visitors; these three covariates explained 45% of the variation in fAM concentration among males. Comparison of fGCM with fPM showed a negative trend, indicating increasing adrenal hormones may decrease reproductive function among female red pandas. The study thus suggests that zoo management should consider increasing feeding frequency, providing larger enclosures with more trees, and regulating visitor numbers to reduce stress and increase reproductive fitness among red pandas.
ARTICLE | doi:10.20944/preprints202201.0357.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: predictive modeling; biomarker; cerebrospinal fluid; cross-sectional study; neurodegenerative disease
Online: 24 January 2022 (12:59:55 CET)
In recent years, metabolomics has been used as a powerful tool to better understand the physiology of neurodegenerative diseases and identify potential biomarkers for progression. We used targeted and untargeted aqueous, and lipidomic profiles of the metabolome from human cerebrospinal fluid to build multivariate predictive models distinguishing patients with Alzheimer’s disease (AD), Parkinson’s disease (PD), and healthy age-matched controls. We emphasize several statistical challenges associated with metabolomic studies where the number of measured metabolites far exceeds sample size. We found strong separation in the metabolome between PD and controls, as well as between PD and AD, with weaker separation between AD and controls. Consistent with existing literature, we found alanine, kynurenine, tryptophan, and serine to be associated with PD classification against controls, while alanine, creatine, and long chain ceramides were associated with AD classification against controls. We conducted a univariate pathway analysis of untargeted and targeted metabolite profiles and find that vitamin E and urea cycle metabolism pathways are associated with PD, while the aspartate/asparagine and c21-steroid hormone biosynthesis pathways are associated with AD. We also found that the amount of metabolite missingness varied by phenotype, highlighting the importance of examining missing data in future metabolomic studies.
ARTICLE | doi:10.20944/preprints202112.0120.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: aging; NMR spectroscopy; mice; energy metabolism; fat; intestine; metabolomics
Online: 8 December 2021 (12:03:07 CET)
Energy metabolism, including alterations in energy intake and expenditure, is closely related to aging and longevity. Metabolomics studies have recently unraveled changes in metabolite composition in plasma and tissues during aging and have provided critical information to elucidate the molecular basis of aging process. However, the metabolic changes in tissues responsible for food intake and lipid storage have remained unexplored. In this study, we aimed to investigate aging-related metabolic alterations in these tissues. To fill this gap, we employed NMR-based metabolomics in several tissues, including different parts of the intestine (duodenum, jejunum, ileum) and brown/white adipose tissues (BAT, WAT) of young (9-10 weeks) and old (96-104 weeks) wild-type (mixed genetic background of 129/J and C57BL/6) mice. We further included plasma and skeletal muscle of the same mice to verify previous results. Strikingly, we found that duodenum, jejunum, ileum, and WAT do not metabolically age. In contrast, plasma, skeletal muscle, and BAT show a strong metabolic aging phenotype. Overall, we provide first insights into the metabolic changes of tissues essential for nutrient uptake and lipid storage and have identified biomarkers for metabolites that could be further explored to study the molecular mechanisms of aging.
ARTICLE | doi:10.20944/preprints202112.0073.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: MicroRNAs; miR-126; mir-197; mir-223; Cardiometabolic Disease; Diabetes; Cardiovascular disease; Atherosclerosis; Inter Media Thickness
Online: 6 December 2021 (12:52:25 CET)
We aim to investigate if serum levels of microRNAs: miR-126, mir-197 and mir-223, previously implicated in cardiometabolic disease, are reproducibly associated with incident-diabetes (inc-DM), incident-cardiovascular disease (inc-CVD) and with carotid atherosclerosis (measured for the maximum thickness of the intima-media of the carotid bulb (IMT)). The microRNAs were measured, one: in serum of 553 subjects from the baseline exam of the Swedish prospective cohort, Malmö Diet and Cancer Study (MDC-CC), with 169 subjects who developed CVD and 140 DM (16 years follow-up) and, two: in 1221 subjects from the Malmö Offspring Study (MOS), with 14 de-veloped CVD and 12 DM (3.7 years follow-up). Multivariate logistic and linear regression models were used to investigate the relationship of serum-concentrations of the microRNAs and inc-DM, inc-CVD, IMT-bulb respectively. In MDC-CC, miR-126 showed significant positive association with inc-DM (p= 0.01) whereas in fully adjusted model, the association was borderline significant (p= 0.05). The results were not replicated in MOS. There was no consistent significant association between the microRNAs with IMT or inc-CVD in any cohort. Our results do not support previous reports on significant associations between these microRNAs and the risk of CMD, as they were not reproducible in our cohorts. In addition, the directionality of any associations found were not consistent with those previously reported.
ARTICLE | doi:10.20944/preprints202111.0285.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: depression; serum levels; phthalates; bisphenols
Online: 16 November 2021 (09:53:20 CET)
Public concern has emerged about the effects of endocrine disruptor compounds (EDCs) on neuropsychiatric disorders. Preclinical evidence suggests that exposure to EDCs is associated with the development of the major depressive disorder (MDD) and could result in neural degeneration. The interaction of EDCs with hormonal receptors is the best-described mechanism of their biological activity. However, the dysregulation of the hypothalamic-pituitary-gonadal adrenal axis has been reported and linked to neurological disorders. On the other hand, at a worldwide level and in Mexico, the incidence of MDD has recently been increasing. Of note, in Mexico, there are no clinical associations on blood levels of EDCs and the incidence of the MDD. Methodology: Thus, we quantified for the first time the serum levels of parent compounds of two bisphenols and four phthalates in patients with MDD. Results: The levels of di-ethyl-hexyl-phthalate (DEHP), butyl-benzyl-phthalate (BBP), di-n-butyl phthalate (DBP), and di-ethyl-phthalate (DEP), bisphenol A (BPA), and bisphenol S (BPS) were determined with a gas chromatograph-mass spectrometer. Results/ conclusion: We found significant differences between concentrations of BBP between controls and patients with MDD.
ARTICLE | doi:10.20944/preprints202110.0291.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Succinate; SUCNR1; GDM; Placenta; Endothelial cells, Angiogenesis
Online: 20 October 2021 (12:35:18 CEST)
Placental hypervascularization has been reported in pregnancy-related pathologies such as gestational diabetes mellitus (GDM). Nevertheless, the underlying causes behind this abnormality are not well understood. In this study, we addressed the expression of SUCNR1 (cognate succinate receptor) in human placental endothelial cells and hypothesized that succinate-SUCNR1 axis might play a role in the placental hypervascularization reported in GDM. We measured significantly higher succinate levels in placental tissue lysates from women with GDM relative to matched controls. In parallel, SUCNR1 protein expression was upregulated in GDM tissue lysates as well as in isolated diabetic fetoplacental arterial endothelial cells (FpECAds). A positive correlation of SUCNR1 and vascular endothelial growth factor (VEGF) protein levels in tissue lysates indicated a potential link between succinate-SUCNR1 axis and placental angiogenesis. In our in-vitro experiments, succinate prompted hallmarks of angiogenesis in human umbilical vein endothelial cells (HUVECs) such as proliferation, migration and spheroid sprouting. These results were further validated in fetoplacental arterial endothelial cells (FpECAs), where succinate induced endothelial tube formation. VEGF gene expression was increased in response to succinate in both HUVECs and FpECAs. Yet, knockdown of SUCNR1 in HUVECs led to suppression of VEGF gene expression and abrogated the migratory ability and wound healing in response to succinate. In conclusion, our data underline SUCNR1 as a promising metabolic target in human placenta and as a potential driver of enhanced placental angiogenesis in GDM.
REVIEW | doi:10.20944/preprints202110.0005.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Brown adipose tissue; beige adipose tissue; obesity; cold exposure; uncoupling protein-1, beta-adrenergic receptor; energy expenditure; adipose browning; micro-RNA
Online: 1 October 2021 (11:30:39 CEST)
Obesity-associated metabolic abnormalities comprise of a cluster of conditions including dyslipidemia, insulin resistance, diabetes, and cardiovascular diseases that has affected more than 650 million people all over the globe. Obesity results from accumulation of white adipose tissues mainly due to the chronic imbalance of energy intake and energy expenditure. Variety of approaches to treat or prevent obesity, including lifestyle interventions, surgical weight loss procedures and pharmacological approaches to reduce energy intake and increase energy expenditure have failed to substantially decrease the prevalence of obesity. Brown adipose tissue (BAT), the primary source of thermogenesis in infants and small mammals may represent a promising therapeutic target to treat obesity by promoting energy expenditure through non-shivering thermogenesis mediated by mitochondrial uncoupling protein 1 (UCP1). Since the confirmation of functional BAT in adult humans by several groups, approximately a decade ago and its association with a favorable metabolic phenotype, intense interest on the significance of BAT in adult human physiology and metabolic health has emerged within the scientific community to explore its therapeutic potential for the treatment of obesity and metabolic diseases. Substantially decreased BAT activity in individuals with obesity indicates a role for BAT in setting of human obesity. On the other hand, BAT mass and its prevalence has been reported to correlate with lower body mass index (BMI), decreased age and glucose levels, leading to lower incidence of cardio metabolic diseases. Increased cold exposure in adult humans with undetectable BAT was associated with decreased body fat mass and increased insulin sensitivity. Deeper understanding of the role of BAT in human metabolic health and its inter-relationship with body fat distribution and deciphering proper strategies to increase energy expenditure by either increasing functional BAT mass, or inducing white adipose browning holds the promise for possible therapeutic avenues for the treatment of obesity and associated metabolic disorders.
ARTICLE | doi:10.20944/preprints202109.0268.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: flavan-3-ols; adipose; browning; catecholamine; sympathetic nerve
Online: 15 September 2021 (15:16:21 CEST)
We previously found increases in uncoupling protein (Ucp)-1 transcription in brown adipose tissue (BAT) of mice following a single oral dose of flavan 3-ols (FL), a fraction of catechins and procyanidins. It was confirmed that these changes were totally reduced by co-treatment of adrenaline blockers. According to these previous results, FL possibly activates sympathetic nervous system (SNS). In this study, we confirmed the marked increase in urinary catecholamine (CA) s projecting SNS activity following a single dose of 50 mg/kg FL. In addition, we examined the impact of the repeated administration of 50 mg/kg FL for 14 days on adipose tissues in mice. In BAT, FL tended to increase the level of Ucp-1 along with thermogenic transcriptome factors, such as peroxisome proliferator-activated receptor γ coactivator (PGC)-1α and PR domain-containing (PRDM)1. Transcription of browning markers, such as CD137 and transmembrane protein (TMEM) 26 in addition to PGC-1α were increased in epididymal adipose (eWAT) by FL. A multilocular morphology with cell size reduction was shown in the inguinal adipose (iWAT), together with increasing the level of Ucp-1 following administration of FL. These results suggest that FL produces browning in adipose through activation of the SNS.
ARTICLE | doi:10.20944/preprints202108.0235.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Pancreatic Ductal Adenocarcinoma; metabolites; cholestatic (obstructive) jaundice; lipoprotein; inflammation; tumour stages
Online: 10 August 2021 (14:08:27 CEST)
Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a characteristic dysregulated metabolism. Abnormal clinicopathological features linked to defective metabolic and inflammatory response pathways can induce PDAC development and progression. In this study, we investigated the metabolites and lipoproteins profiles of PDAC patients of African ancestry. Nuclear Magnetic Resonance (NMR) spectroscopy was conducted on serum obtained from consenting individuals (34 PDAC, 6 Chronic Pancreatitis, and 6 healthy participants). Seventy-five signals were quantified from each NMR spectrum. The Liposcale test was used for lipoprotein characterization. Spearman’s correlation and Kapan Meier tests were conducted for correlation and survival analyses respectively. In our patient cohort, the results demonstrated that levels of metabolites involved in the glycolytic pathway increased with the tumour stage. Raised ethanol and 3-hydroxybutyrate were independently correlated with a shorter patient survival time, irrespective of tumour stage. Furthermore, increased levels of bilirubin resulted in an abnormal lipoprotein profile in PDAC patients. Additionally, we observed that the levels of a panel of metabolites (such as glucose, lactate) and lipoproteins correlated with those of inflammatory markers. Taken together, the metabolic phenotype can help distinguish PDAC severity and be used in predicting patient survival and in informing treatment intervention.
REVIEW | doi:10.20944/preprints202108.0123.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolic syndrome; caffeinated coffee; decaffeinated coffee; green coffee extract; chlorogenic acid
Online: 4 August 2021 (22:04:19 CEST)
Coffee is rich in phenolic acids, such as caffeic acid and chlorogenic acid (CGA). Polyphenol-rich diets have been shown to reduce the risk of metabolic syndrome (MeTS). Background and Objectives: This systematic review and meta-analysis discusses the effects of coffee consumption and its dose-response on MeTS parameters. Materials and Methods: PubMed and Scopus® were searched for relevant articles published between 2015 and 2020. This review focused on randomised controlled trials (RCTs) investigating the effect of coffee consumption on anthropometric measurements, glycaemic indices, lipid profiles, and blood pressure. Data from relevant studies were extracted and analysed using random, fixed, or pooled effects models with 95% confidence intervals (CIs). Results: Green coffee extract (GCE) supplementation (180 to 376 mg) was found to reduce waist circumference (weighted mean difference (WMD) = -0.39; 95% CI: -0.68, -0.10), triglyceride levels (WMD = -0.27; 95% CI: -0.43, -0.10), high-density lipoprotein-cholesterol levels (WMD = 0.62; 95% CI: 0.34, 0.90), systolic blood pressure (WMD = -0.44; 95% CI: -0.57, -0.32), and diastolic blood pressure (WMD = -0.83; 95% CI: -1.40, -0.26). Decaffeinated coffee (510.6 mg) reduced the fasting blood glucose levels (WMD = -0.81; 95% CI: -1.65, 0.03). The meta-analysis showed that the intake of GCE containing 180 to 376 mg of CGA (administered in a capsule) and liquid decaffeinated coffee containing 510.6 mg of CGA improved the MeTS outcomes in study participants. Conclusions: The findings of the review suggested that the effect of coffee on MeTS parameters varies depending on the types and doses of coffee administered. A more detailed RCT on specific coffee doses (with adjustment for energy and polyphenol intake) and physical activity is needed to further confirm the observed outcomes.
ARTICLE | doi:10.20944/preprints202104.0655.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Meteorin-like hormone, irisin, adipomyokines, bone markers, Osteoactivin , Syndecan, OPG, Osteonectin, type 2 diabetes, obesity.
Online: 26 April 2021 (10:57:31 CEST)
The musculoskeletal system consisting of bones and muscles have been recognized as endocrine organs secreting hormones that are involved in regulating metabolic and inflammatory pathways. Obesity and type 2 diabetes (T2D) are associated with several musculoskeletal system complications. We hypothesized that an interaction exists between adipomyokines namely, irisin and METRNL, and various bone markers in individuals with obesity and T2D. A total of 228 individuals were enrolled in this study, including 124 non-diabetic and 104 T2D. A Multiplex assay was used to assess the level of various bone markers namely Osteoactivin, Syndecan, osteoprotegerin (OPG) and osteonectin/SPARC. Our data shows elevated levels of Osteoactivin, Syndecan, OPG and SPARC in T2D as compared to non-T2D individuals (p ≤ 0.05). Using Spearman’s correlation, irisin was positively correlated only with Osteoactivin and OPG (p < 0.05). Similarly, a positive association was observed between METRNL and Osteoactivin (p < 0.05). The strong positive association shown in our study between irisin, METRNL and various bone markers emphasises the strong interaction between these organs. This suggests that a dysregulation in the functional interaction between these molecules could play a possible role in the development of bone and muscle related complications that are associated with obesity and T2D.
ARTICLE | doi:10.20944/preprints202103.0273.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: testicular germ cell tumors (TGCTs); human seminoma; p75 neurotrophin receptor (p75NTR); p75NTR -signaling.
Online: 9 March 2021 (14:52:34 CET)
Several studies have demonstrated that the p75NTR low-affinity receptor of Nerve Growth Factor (NGF), is produced in abnormally large amounts in several human cancer types. However, the role of p75NTR varies substantially depending on cell context, so that a dual role of this receptor protein in tumor cell survival and invasion, as well as cell death, has been supported in recent studies. Herein we explored for the first time the expression of p75NTR in human specimens (nr=40) from testicular germ cell tumors (TGCTs), mostly seminomas. Nuclear overexpression of p75NTR was detected by immunohistochemistry in tumor tissue as compared to normal tissue, whereas neither NGF nor its high-affinity TrkA receptor was detected. An increased nuclear staining of phospho-JNK, belonging to the p75NTR signaling pathway, and its pro-apoptotic target gene, p53, was concomitantly observed. Interestingly, our analysis revealed that decreased expression frequency of p75NTR, p-JNK, and p53 was related to staging progression, thus suggesting that p75NTR may represent a specific marker of differentiation in TGCTs.
ARTICLE | doi:10.20944/preprints202101.0601.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: menopause, women, phytoestrogens, bread, soy
Online: 29 January 2021 (06:05:18 CET)
Menopause is the last step in the reproductive history of a woman. The ovaries stop producing hormones and the body reacts by lowering its functions, including the neuronal one. Phytoestrogens are plant products with estrogen-like activity able to affect many body functions. The aim of the present experiment was to study the effects of 30 days of regular consumption of a soy-enriched bread containing a known amount of phytoestrogens (genistein and daidzein). Women at climacteric, within 5 years or more than 5 years of menopause, were asked to include in their diet 200 g/day of a bread containing 40 mg of phytoestrogens. The effect on common menopausal symptoms and neurophysiological, hormonal and antioxidant parameters were determined before and after 30 days through questionnaires and experimental tests. Phytoestrogens were measured in the urine. In all groups, there was a significant increase of phytoestrogens in the urine and a decrease of the classical symptoms of menopause as well as a significant improvement in attentional performance tests, the quality of life index and pain intensity. Phytoestrogens present in the soy-enriched bread, are an important supplement in aging women due to their ability to induce estrogen-like effects without the potential side effects of estrogens.
ARTICLE | doi:10.20944/preprints202009.0185.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: eel luteinizing hormone receptor; constitutively activating mutation; inactivating mutation; cyclic adenosine monophosphate response; cell surface loss of receptor
Online: 8 September 2020 (10:56:48 CEST)
We analyzed signal transduction of three constitutively activating mutants (M410T, L469R, and D590Y) and two inactivating mutants (D417N and Y558F) of the eel luteinizing hormone receptor (eel LHR), known to occur in human LHR. The objective of this study was to assess the functional effects of these mutations in signal transduction and cell surface loss of receptor. Mutant receptors were transiently expressed in Chinese hamster ovary (CHO-K1) cells. Eel LH-stimulated accumulation of cyclic adenosine monophosphate (cAMP) was measured by homogeneous time-resolved fluorescence (HTRF) assays. The loss of receptors from the cells surface was measured using an enzyme-linked immunosorbent assay (ELISA) in human embryonic kidney (HEK) 293 cells. The cAMP response in cells expressing the wild type eel LHR was increased in a dose-dependent manner using eel LH ligand stimulation. Compared with the wild type, cells expressing the activating mutants (M410T, L469R, and D590Y), exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist stimulation, respectively. Their maximal responses to agonist stimulation were approximately 65%, 52%, and 98%, respectively, of those of the wild type. The inactivating mutants (D417N and Y558F) did not completely impair signal transduction, and their maximal responses were only 33% and25 % of those of wild type. These data clearly showed that the eel LHR-L469R and D590Y, activating mutants enhanced the rate of the loss of cell surface receptors following treatment with eel LH. Thus, the loss of cell surface receptors in cells expressing mutant eel LHRs was consistent with the eel LH agonist-induced production of cAMP. Our results suggested that the activation of the eel LHR requires appropriate loss of LHR-ligand complexes from the cell surface.
REVIEW | doi:10.20944/preprints202009.0004.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolomics; vaccines; infections; integrative metabolomics; systems biology; diagnosis; response detection
Online: 1 September 2020 (10:25:03 CEST)
Approaches to identification of metabolites have progressed from early biochemical pathway evaluation to modern high dimensional metabolomics which is a powerful tool to identify and characterize biomarkers of health and disease. While traditionally considered relevant in the context of classic metabolic diseases, immunometabolism has emerged as an important area of study as leukocytes generate key metabolites important to innate and adaptive immunity. Herein we discuss the metabolomic signatures and pathways perturbed during infection as well as vaccination. For example, changes in lipid and amino acid pathways (e.g., tryptophan, serine, and threonine) have been noted during infection while carbohydrate and bile acid pathways have shift upon vaccination. Metabolomics holds substantial promise to provide fresh insight into the molecular mechanisms underlying host response to infection and vaccination, and its integration with other systems biology platforms will add further impact to our studies of health and disease.
REVIEW | doi:10.20944/preprints202008.0685.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: vitamin D; muscle; parathyroid hormone; vitamin D-binding protein
Online: 30 August 2020 (18:31:44 CEST)
Vitamin D, unlike the micronutrients, vitamins A, E and K, is largely obtained, not from food, but by the action of solar UV light on its precursor, 7-dehydrocholesterol, in skin. With the decline in UV light intensity in winter, most skin production of vitamin D occurs in summer. Because no defined storage organ or tissue has been found for vitamin D, it has been assumed that adequate vitamin D status in winter can only be maintained by oral supplementation. Skeletal muscle cells have now been shown to incorporate the vitamin D-binding protein (DBP) from blood into the cell cytoplasm where it binds to cytoplasmic actin. This intracellular DBP provides an array of specific binding sites for 25-hydroxyvitamin D (25(OH)D) which diffuses into the cell from the extracellular fluid. When intracellular DBP undergoes proteolytic breakdown, the bound 25(OH)D is then released and diffuses back into blood. This uptake and release of 25(OH)D by muscle, accounts for the very long half-life of this metabolite in the circulation. As 25(OH)D concentration in blood declines in winter, its cycling in and out of muscle cells appears to be upregulated. Parathyroid hormone is the most likely factor enhancing the repeated cycling of 25(OH)D between skeletal muscle and blood. This mechanism appears to have evolved to maintain adequate vitamin D status in winter.
REVIEW | doi:10.20944/preprints202008.0417.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: hepatic fibrosis; hepatocullar carcinoma; vibration controlled transient elastography
Online: 19 August 2020 (13:00:28 CEST)
The prevalence of obesity or metabolic syndrome is increasing worldwide (“Globally metabodemic”). Approximately 25% of adult general population is suffering from nonalcoholic fatty liver disease (NAFLD) which has become serious health problem. Hepatic fibrosis is the most significant determinant of all cause and liver -related mortality in NAFLD. Noninvasive test (NIT) should be urgently required to evaluate hepatic fibrosis in NAFLD. Fibrosis-4 (FIB-4) index is the 1st triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness especially for general physicians or endocrinologists, although FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the 2nd step after triaging by FIB-4 index. The leading cause of mortality in NAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. NAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation (SLKT). FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocullar carcinoma (HCC) but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, FIB- 4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of FIB-4 index as 1st step NIT in management of NAFLD.
REVIEW | doi:10.20944/preprints202007.0314.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: hepatic fibrosis; Mac-2 binding protein glycated isomer; apoptosis inhibitor of macrophage; patatin-like phospholipase domain-containing protein 3; α-fetoprotein; PIVKA-II
Online: 14 July 2020 (13:55:16 CEST)
Nonalcoholic fatty liver disease (NAFLD) is becoming the leading cause of hepatocellular carcinoma (HCC), liver-related mortality, and liver transplantation. There is reasonable epidemiological cohort data to recommend surveillance of patients with NAFLD based upon the incidence of HCC. The American Gastroenterology Association (AGA) expert review published in 2020 recommend that NAFLD patients with cirrhosis or advanced fibrosis estimated by non-invasive tests (NITs) should consider HCC surveillance. NITs include fibrosis-4 (FIB-4) index, the enhanced liver fibrosis (ELF) test, FibroScan, and MR elastography. The recommended surveillance modality is abdominal ultrasound (US) given that it is cost effective and noninvasive with good sensitivity. However, US is limited in obese patients and those with NAFLD. In NAFLD patients with a high likelihood of having an inadequate US or if US is attempted but inadequate, CT or MRI may be utilized. The GALAD score, consisting of age, gender, AFP, lens culinaris-agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II), can help to identify high risk of incident HCC in NAFLD patients. Innovative parameters including Mac-2 binding protein glycated isomer , type IV collagen 7S, free apoptosis inhibitor of macrophage, combination of single nucleoside polymorphisms are expected to be established. Considering a large number of NAFLD population, optimal screening tests must meet several criteria including high sensitivity, cost effectiveness and availability.
ARTICLE | doi:10.20944/preprints202007.0227.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Data integration; Metabolomics; Multi-tissue; Multiblock; Joint and unique multiblock analysis (JUMBA), OnPLS; Multiblock Orthogonal Component Analysis (MOCA)
Online: 11 July 2020 (04:01:03 CEST)
Data integration has been proven to provide valuable information. The information extracted using data integration in the form of multiblock analysis can pinpoint both common and unique trends in the different blocks. When working with small multiblock datasets the number of possible integration methods is drastically reduced. To investigate the application of multiblock analysis in cases where one has few number of samples, we studied a small metabolomic multiblock dataset containing six blocks (i.e. tissue types), only including common metabolites. We used a single model multiblock analysis method called Joint and unique multiblock analysis (JUMBA) and compare it to a commonly used method, concatenated PCA. These methods were used to detect trends in the dataset and identify underlying factors responsible for metabolic variations. Using JUMBA, we were able to interpret the extracted components and link them to relevant biological properties. JUMBA shows how the observations are related to one another, the stability of these relationships and to what extent each of the blocks contribute to the components. These results indicate that multiblock methods can be useful even with a small number of samples.
ARTICLE | doi:10.20944/preprints202007.0211.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Ionotropin; Steroid phosphocholine esters; pre-eclampsia; endogenous ouabain; DLM; PTSD
Online: 10 July 2020 (09:55:05 CEST)
Cardiotonic glycoside toxins, originally isolated from plants or amphibians, have been proposed as mammalian cardiotonic hormones. This paper is a review and update of the discovery of [i] a new class of steroid hormones, [ii] the path for their biosynthesis and [iii] some preliminary data on their function. The compounds are phosphoester conjugates and share a characteristic structural feature, a lactone ring, with [a] one class of synthetic potassium sparing diuretics and with [b] plant and amphibian cardiotonic steroids. Purification was initially monitored by cross reaction with steroid sulfate assays and later with digoxin-specific assays. Six compounds were purified by HPLC to near homogeneity and characterized by Tandem mass spectroscopy (MS-MS) and 31P-NMR. Three were digoxin-like materials (DLM) with 23 carbon atoms. The two extra carbon atoms form a spiral lactone E-ring. Several additional spiral lactones have been identified by MS-MS. In a pilot study, based on MS analysis, we evaluated phosphocholine steroid levels in individual serum samples in patients with pre-eclampsia (n=20). The control group of normotensive pregnant women (n=20) was used to estimate the mean and standard deviation. Twelve of the women with pre-eclampsia had a z-score over 2 for at least one of the four phosphocholine steroids. In contrast, only 1 sample from the normotensive women had a z-score over 2. The observation that there are two patterns, one with elevated phosphocholine steroid levels and one without the elevation, suggests that there may be two different underlying causes of pre-eclampsia. We now need to extend the study to determine which pattern predicts progression to life-threatening hypertension in pregnant women. This pilot study illustrates that it is possible to evaluate individual endogenous cardiotonic hormones without relying on antibodies developed to plant or amphibian toxins.
ARTICLE | doi:10.20944/preprints202006.0245.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: COVID-19; Metabolic syndrome; Comorbidity; Enrichment analysis; biological processes and pathways
Online: 21 June 2020 (09:52:10 CEST)
The risk factors associated with COVID-19 related severity, morbidity, and mortality, i.e., obesity (often associated with NAFLD), hyperglycemia, hypertension and dyslipidemia all cluster together as metabolic syndrome (MetS). Instead of studying association of these risk factors with COVID-19, it makes sense studying the association between MetS on one hand and COVID-19 on the other. This study explores a molecular basis underpinning the above association. Severity of COVID-19 patients with MetS could be due to functional alterations of host proteins due to their interactions with viral proteins. We collected data from Enrichr (https://amp.pharm.mssm.edu/Enrichr/), DisGeNET (https://www.disgenet.org/) and others and carried out enrichment analysis using Enrichr. Various biological processes and pathways associated with viral protein interacting partners are known to involve in metabolic diseases. The molecular pathways underlying insulin resistance, insulin signaling and insulin secretion are not only involved in diabetes but also in CVD and obesity (associated with non-alcoholic fatty liver disease; NAFLD). Lipid metabolism/lipogenesis, fatty acid oxidation and inflammation are associated with MetS. Viral interacting host proteins are associated and enriched with terms like hyperglycemia, coronary artery disease, hypertensive disease related to CVD and liver diseases in DisGeNET. Association of viral interacting proteins with disease-relevant biological processes, pathways and disease-related terms suggests that altered host protein function following interaction with viral proteins might contribute to frequent occurrence and/or severity of COVID-19 in subjects with MetS. Such analysis not only provides a molecular basis of comorbidity but also incriminates host proteins in viral replication, growth and identifies possible drug targets for intervention.
ARTICLE | doi:10.20944/preprints202005.0341.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: AGEs; aortic calcification; type 2 diabetes mellitus; diabetes-related complications
Online: 21 May 2020 (09:46:56 CEST)
The aim of this study was to evaluate the relationship between serum levels of advanced glycation end products (AGEs) and abdominal aortic calcification (AAC) in patients with type 2 diabetes mellitus (DM2). This was a prospective cross-sectional study conducted from January 2017 to June 2018. One-hundred and four consecutive patients with DM2 were given lateral lumbar X-rays in order to quantify aortic abdominal calcification AAC. Circulating levels of AGEs and classical cardiovascular risk factors were determined. Clinical history was also registered. Patients with higher AGEs values had higher grades of aortic calcification and higher number of diabetic related complications. Multivariate logistic regression analysis showed that being older, male and having high levels of AGEs and triglycerides were the independent risk factors associated to moderate-severe AAC when compared to no-mild AAC. Our results suggest that AGEs plays a role in the pathogenesis of aortic calcifications. In addition, the measurement of AGEs levels may be useful for assessing the severity of AAC in the setting of diabetic complications.
ARTICLE | doi:10.20944/preprints202003.0148.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: osteosarcoma; cancer; tumor; vitamin D; vitamin D deficiency; vitamin D receptor; vdr; mitochondria; ROS; SOD; SOD1; SOD2; superoxide; superoxide dismutase
Online: 9 March 2020 (02:40:08 CET)
Superoxide, a form of reactive oxygen species (ROS), is catabolized by superoxide dismutase (SOD) and contributes to carcinogenesis via the oxidative damage it inflicts on cells. The aim of this research was to analyze the potential vitamin D-mediated regulation of the antioxidative “SOD1-to-SOD2 switch” within the human MG-63 osteosarcoma model. For this study; real-time PCR analysis was performed using MG-63 cells exposed to metabolically active 1,25(OH)2D3. Frist; a sustained statistically significant >2-fold suppression of proliferating cell nuclear antigen (PCNA) transcripts was observed after 10nM but not at 100nM of 1,25(OH)2D3 treatment; suggesting a cytostatic effect. In order to assess regulators of mitochondrial oxidative phosphorylation; gene expression of COX2 and COX4l1 of the mitochondrial complex IV and antioxidative enzymes (SOD1; SOD2 and Catalase (CAT)) were monitored. For COX2 and COX4l1; no changes in gene expression were observed. However; a concomitant decrease in CAT and SOD1 mRNA; and increase in SOD2 mRNA after 24 hours of 10nM 1,25(OH)2D3 treatment were observed. A ~8-fold increase in SOD2 mRNA was apparent after 48 hours. The significant increase in SOD2 activity in the presence of vitamin D indicates an antioxidant potential and sensitization of vitamin D during osteosarcoma transformation and mitochondrial detoxification over time.
ARTICLE | doi:10.20944/preprints201909.0103.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: PORD; congenital adrenal hyperplasia; POR; CY19A1; CYP21A2, CYP17A1
Online: 12 February 2020 (02:57:08 CET)
Context: Mutations in Cytochrome P450 oxidoreductase (POR) cause a form of congenital adrenal hyperplasia (CAH). We are reporting a novel R550W mutation in POR identified in a 46, XX patient with signs of aromatase deficiency. Objective: Analysis of aromatase deficiency from R550W mutation in POR. Design, Setting, and Patient: Both the child and the mother had signs of virilization. Ultrasound revealed the presence of uterus and ovaries. No defects in CYP19A1 were found, but further analysis with a targeted Disorders of Sexual Development NGS panel (DSDSeq.V1, 111 genes) on a NextSeq (Illumina) platform in Madrid and Barcelona, Spain, revealed compound heterozygous mutations c.73_74delCT/p.L25FfsTer93 and c.1648C>T/p.R550W in POR. WT and R550W POR were produced as recombinant proteins and tested with multiple cytochrome P450 enzymes at University Children’s Hospital, Bern, Switzerland. Main Outcome Measure and Results: R550W POR showed 41% of the WT activity in cytochrome c and 7.7% activity for reduction of MTT. Assays of CYP19A1 showed a severe loss of activity and CYP17A1, as well as CYP21A2 activities, were also lost by more than 95%. Loss of CYP2C9, CYP2C19, and CYP3A4 activities was observed for the R550W-POR. Predicted adverse effect on aromatase activity as well as a reduction in binding of NADPH was confirmed. Conclusions: Pathological effects due to POR R550W were identified, expanding the knowledge of molecular pathways associated with aromatase deficiency. Screening of the POR gene may provide a diagnosis in CAH without defects in genes for steroid metabolizing enzymes.
ARTICLE | doi:10.20944/preprints202002.0019.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: metabolomics; LC-MS; mass spectrometry; metabolic profiling; computational; statistical; unsupervised learning; supervised learning; pathway analysis
Online: 3 February 2020 (05:54:14 CET)
Metabolomics analysis generates vast arrays of data, necessitating comprehensive workflows involving expertise in analytics, biochemistry and bioinformatics, in order to provide coherent and high-quality data that enables discovery of robust and biologically significant metabolic findings. In this protocol article, we introduce NoTaMe, an analytical workflow for non-targeted metabolic profiling approaches utilizing liquid chromatography–mass spectrometry analysis. We provide an overview of lab protocols and statistical methods that we commonly practice for the analysis of nutritional metabolomics data. The paper is divided into three main sections: the first and second sections introducing the background and the study designs available for metabolomics research, and the third section describing in detail the steps of the main methods and protocols used to produce, preprocess and statistically analyze metabolomics data, and finally to identify and interpret the compounds that have emerged as interesting.
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Angelica gigas Nakai; triglycerides; VLDL-C; TG/HDL-C; atherogenic index
Online: 22 December 2019 (13:56:42 CET)
Background: Angelica gigas Nakai, Korean dang-gui, has long been widely used in traditional treatment methods. There have been a number of studies of the health effects of A. gigas and related compounds, but studies addressing effects on blood triglycerides (TG) are lacking. To investigate the effects of A. gigas Nakai extract (AGNE) on TG in Korean subjects, we carried out a 12-week, randomized, double-blind, placebo-controlled clinical trial. Methods: Subjects who met the inclusion criterion (130 mg/dL ≤ fasting blood TG ≤ 200 mg/dL) were recruited for this study. One hundred subjects were assigned to the AGNE group (n=50) or the placebo group (n=50), who were given 1g/day of AGNE (as a gigas Nakai extract 200mg/d) in capsules, and the control group for 12 weeks. Outcomes were efficacy TG, lipid profiles, atherogenic index, and safety parameters were assessed initially for a baseline measurement and after 12 weeks. Results: After 12 weeks of supplementation, TG and very low-density lipoprotein cholesterol (VLDL-C) concentration and TG/HDL-C ratio in the AGNE group were significantly reduced compared to the placebo group (p <0.05). No significant changes in any safety parameter were observed. Conclusions: These results suggest that ingestion of AGNE may improve TG and be useful to manage or prevent hypertriglyceridemia.
ARTICLE | doi:10.20944/preprints201911.0343.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: anti-apoptosis; anti-oxidant; curcumin; hyperglycemia; hyperlipidemia
Online: 27 November 2019 (09:57:14 CET)
Curcumin is the main secondary metabolites of Curcuma longa and other Curcuma spp, and has been reported to have some potential in preventing and treating some physiological disorders. This study investigated the effect curcumin in inhibiting high-fat diet and streptozotocin (STZ)-induced hyperglycemia and hyperlipidemia in rats. Twenty-six male Sprague-Dawley (SD) rats (170-190 g) were randomly divided into a standard food pellet diet group (Control group), a high-fat diet and streptozotocin group (HF+STZ group), and a high-fat diet combined with curcumin and STZ group (HF+ Cur +STZ group). Compared with the HF+STZ group, the HF+Cur+STZ group exhibited significantly reduced fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (AST) and aspartate transaminase (ALT) levels, and liver coefficients; in the livers of these rats, the expression of malondialdehyde (MDA) and Bax was downregulated, whereas that of superoxide dismutase (SOD) and Bcl-2 was upregulated. Moreover, the liver histology of these rats was improved and resembled that of the control rats. These results suggest that curcumin prevents high-fat diet and STZ-induced hyperglycemia and hyperlipidemia, mainly via anti-oxidant and anti-apoptotic mechanisms in the liver.
ARTICLE | doi:10.20944/preprints201911.0042.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: olivo-ponto-cerebellar atrophy (OPCA); amyotrophic lateral sclerosis (ALS); tauopathy; leukodystrophy; mass spectrometry; RT-qPCR; Ceramide Synthase (CERS2/CERS1); Serine Palmitoyltransferase 2 (Sptlc2); neutral Sphingomyelinase (Smpd3); neutral Ceramidase (Asah2); Fatty Acid Elongase (Elovl1/4/5); SCA34; SCA38; acid Sphingomyelinase (ASMase, Smpd1)
Online: 5 November 2019 (03:04:02 CET)
Ataxin-2 (ATXN2) acts during stress-responses, modulating mRNA translation and nutrient metabolism. Atxn2 knockout mice exhibit progressive obesity, dyslipidemia and insulin resistance. Conversely, the progressive ATXN2 gain-of-function due to polyGlutamine (polyQ) expansions leads to a dominantly inherited neurodegenerative process named spinocerebellar ataxia type 2 (SCA2), with early adipose tissue loss and late muscle atrophy. We tried to understand lipid dysregulation in a SCA2 patient brain and in an authentic mouse model. Thin layer chromatography of a patient cerebellum was compared to the lipid metabolome of Atxn2-CAG100-KnockIn (KIN) mouse spinocerebellar tissue. The human pathology caused deficits of sulfatide, galactosylceramide, cholesterol, C22/24-sphingomyelin and gangliosides GM1a/GD1b, despite quite normal levels of C18-sphingomyelin. Cerebellum and spinal cord from the KIN mouse showed a consistent decrease of various ceramides, with a significant elevation of sphingosine in the more severely affected spinal cord. Deficiency of C24/26-sphingomyelins contrasted with excess C18/20-sphingomyelin. Spinocerebellar expression profiling revealed consistent reductions of CERS protein isoforms, of Sptlc2 and Smpd3, but upregulation of Cers2 mRNA, as prominent anomalies in the ceramide-sphingosine metabolism. Reduction of Asah2 mRNA correlated to deficient S1P levels. In addition, downregulations for the elongase Elovl1, Elovl4, Elovl5 mRNAs and ELOVL4 protein explain the deficit of very-long-chain sphingomyelin. Reduced ASMase protein levels correlated to the accumulation of long-chain sphingomyelin. Overall, a deficit of myelin lipids was prominent in SCA2 nervous tissue at prefinal stage, not compensated by transcriptional adaptation of several metabolic enzymes. Myelination is controlled by mTORC1 signals, so our human and murine observations are in agreement with the known role of ATXN2 yeast, nematode and mouse orthologs as mTORC1 inhibitors and autophagy promoters.
ARTICLE | doi:10.20944/preprints201909.0125.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: adults; dietary pattern; fast food; KNHANES; obesity
Online: 11 September 2019 (14:59:00 CEST)
Background: Few studies have examined multifaceted aspects of fast food consumption and dietary patterns for their effects on obesity. We examined the independent associations of obesity with fast food consumption and dietary pattern in Korean adults. Methods: A total of 19,017 adults aged 19–64y participated from KNHANES 2010-2014. Fast food items were removed from diet and then dietary patterns were generated. Multivariate logistic regression analysis was used to examine the odds for overweight/obesity and central obesity according to fast food consumption and dietary patterns. Results: Fast food consumers were about 10% of Korean adults. Both of White rice and kimchi pattern and Meat and alcohol pattern were associated with low intakes of fiber, calcium, vitamin C, grains, fruit, and milk(p<0.05). Fast food consumers had higher the Meat and alcohol pattern and the Grains, fruit, and milk pattern, and they had lower the White rice and kimchi pattern than non-fast-food-consumers. Fast food consumer were not associated with overweight/obesity, whereas the participants with Meat and alcohol pattern had 14% higher overweight/obesity(95%CI:1.01,1.28) and 16% higher central obesity(95%CI:1.00,1.34). Conclusions: Fast food consumption was not directly associated with obesity, whereas the Meat and alcohol pattern had independent associations with overweight/obesity and central obesity among Korean adults.
ARTICLE | doi:10.20944/preprints201907.0117.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: eel luteinizing hormone receptor, constitutively activating mutation, inactivating mutation, cAMP responses.
Online: 8 July 2019 (12:38:11 CEST)
Luteinizing hormone receptor (LHR) is a member of the seven-transmembrane (TM) receptor family. Several mutations in LHR have been identified in many mammalian species, leading to either constitutive activation or inactivation of the receptor. Mutations in highly conserved regions of the TM domain have been reported. In this study, we analyzed signal transduction by three constitutively active mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of eelLHR known as naturally occurring in human LHR . To directly assess the functional effects of these mutations, site-directed mutant receptors were transiently expressed in CHO-K1 cells and cAMP accumulation stimulated by recombinant eelLH (rec-eelLH) was measured by homogeneous time-resolved fluorescence (HTRF) assays. The cAMP response in cells expressing eelLHR wild-type (eLHR-WT) increased in a dose-dependent manner with rec-eelLH ligand stimulation. Cells expressing the activating eelLHR mutants, M410T, L469R, and D590Y, exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response, respectively. However, their maximal responses were approximately 73, 53, and 92%, respectively, of the maximal response of LHR-WT. The L469R mutant exhibited a particularly marked increase in cAMP production in the absence of agonist. The maximal responses of the inactivating mutants, D383N and Y546F, were 32 and 24% of LHR-WT, respectively. However, the inactivating mutations did not completely impair signal transduction. Thus, we report here the first characterization of activating and inactivating mutations in eelLHR and we show that these mutations have similar effects as those reported for mammalian LHRs. Moreover, eelLHR with activating mutations showed constitutive cAMP responses. These results provide important data on the signal transduction of constitutively active and inactive LHR mutants. Further studies should aim to identify the mechanism responsible for the significant increase in basal cAMP response in the constitutively activated eelLHR mutants.
ARTICLE | doi:10.20944/preprints201907.0089.v1
Online: 5 July 2019 (04:53:09 CEST)
Type 2 diabetes mellitus (T2DM) is a polygenic metabolic disease described by hyperglycemia, which is caused by insulin resistance or reduced insulin secretion. Interaction between various genetic variants and environmental factors triggers T2DM. The main aim of this study was to find the risk associated with genetic variant (rs5210) of KCNJ11gene in the development of T2D in Indian Population. A total number of 300 cases of T2D and 100 control samples were studied to find the polymorphism in KCNJ11 through PCR-RFLP. The genotype and allele frequencies in T2DM cases were significantly different from the control population. We found a significant association of KCNJ11 (rs5210) gene polymorphism with T2DM in North Indian patients indicating the role of this variant in developing risk for T2DM.
CONCEPT PAPER | doi:10.20944/preprints201901.0246.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: reproducibility; minimum guidelines; reporting; data analysis; reporting
Online: 8 March 2019 (09:06:02 CET)
Despite the proposal of minimum reporting guidelines for metabolomics over a decade ago, reporting on the data analysis step in metabolomics studies has been shown to be unclear and incomplete. Major omissions and a lack of logical flow render the data analysis’ sections in metabolomics studies impossible to follow, and therefore replicate or even imitate. Here, we propose possible reasons why the original reporting guidelines have had poor adherence and present an approach to improve their uptake. We present in this paper an R markdown reporting template file that guides the production of text and generates workflow diagrams based on user input. This R Markdown template contains, as an example in this instance, a set of minimum information requirements specifically for the data pre-treatment and data analysis section of biomarker discovery metabolomics studies, (gleaned directly from the original proposed guidelines by Goodacre at al.). These minimum requirements are presented in the format of a questionnaire checklist in an R markdown template file. The R Markdown reporting template proposed here can be presented as a starting point to encourage the data analysis section of a metabolomics manuscript to have a more logical presentation and to contain enough information to be understandable and reusable. The idea is that these guidelines would be open to user feedback, modification and updating by the metabolomics community via GitHub.
ARTICLE | doi:10.20944/preprints201901.0245.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Osteomeles Schwerinae; diabetic retinopathy (DR); spontaneously diabetic Torii (SDT) rat; human retinal microvascular endothelial cells (HRMECs); advanced glycation end products (AGEs); retinal apoptosis; oxidative stress; mitochondrial function; adjunctive effect; combination therapy
Online: 24 January 2019 (08:37:29 CET)
Retinal apoptosis plays a critical role in the progression of diabetic retinopathy (DR), a common diabetic complication. Currently, the tight control of blood glucose levels is the standard approach to prevent or delay the progression of DR. However, prevalence of DR among diabetic patients remains high. Focusing on natural nutrients or herbal medicines that can prevent or delay the onset of diabetic complications, we administered an ethanol extract of the aerial portion of Osteomeles Schwerinae (OSSCE), a Chinese herbal medicine, over a period of 17 weeks to spontaneously diabetic Torii (SDT) rats. OSSCE was found to ameliorate retinal apoptosis through the regulation of advanced glycation end products (AGEs) accumulation, oxidative stress, and mitochondrial function via inhibition of NF-κB activity, in turn through the downregulation of PKCδ, P47phox, and ERK1/2. We further demonstrated in 25 mM glucose-treated human retinal microvascular endothelial cells (HRMECs) that hyperoside (3-O-galactoside-quercetin), quercitrin (3-O-rhamnoside-quercetin), and 2''-O-acetylvitexin (8-C-(2''-O-acetyl-glucoside)-apigenin) were the active components of OSSCE that mediated its pharmacological action. Our results provide evidence that OSSCE is a powerful agent that may directly mediate a delay in development or disease improvement in patients of DR.
ARTICLE | doi:10.20944/preprints201901.0096.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: calcium diet content; mineral homeostasis; skeletal homeostasis; trabecular bone; PTH(1-34); rat
Online: 10 January 2019 (11:38:42 CET)
The present study is the second step (concerning the normal-diet restoration) of the our previous one (concerning the calcium-free diet) to determine whether the normal-diet restoration, with/without concomitant PTH(1-34) administration, can influence amounts and deposition sites of the total bone mass. Histomorphometric evaluations and immunohistochemical analysis for Sclerostin expression were conducted on the vertebral bodies and femurs in rat model. The final goals are: i) to define timing and manners of bone mass changes when calcium is restored in the diet; ii) to analyze the different involvement of the two bony architectures having different metabolism (i.e. trabecular versus cortical bone); iii) to verify the eventual role of PTH(1-34) administration. Results evidenced the greater involvement of the trabecular bone with respect to the cortical one, in answering to different calcium diet content, and the effect of PTH mostly in the recovery of trabecular bony architecture. The main findings emerged from the present study are: i) the importance of the interplay between mineral homeostasis and skeletal homeostasis in modulating and guiding bone answers to dietary/metabolic alterations and ii) the evidence that the more involved bony architecture is the trabecular one, the most susceptible to the dynamical balance of the two homeostases.
ARTICLE | doi:10.20944/preprints201901.0073.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Phenylbutyrate, PFKL, Obesity, UCP1, Brown adipose tissue
Online: 8 January 2019 (15:22:39 CET)
Obesity, which is characterized by an excessive accumulation of body fat, is one of the critical factors causing metabolic syndrome. Many studies have been performed to identify appropriate agents to control obesity, but toxicity remains a problem. Herein, we identified that phenylbutyrate (PBA), which has been used to treat urea cycle disorder with very low toxicity for a long time, efficiently inhibited high fat-induced body weight gain in a diet-induced obesity mouse model (DIO model). PBA treatment decreased body fat mass and increased lean composition. Moreover, PBA increased brown adipose tissue (BAT) activity by increasing glucose uptake, thereby improving glucose tolerance and insulin tolerance. Interestingly, PBA could induce the expression of phosphofructokinase (PFKL), a key enzyme in the glycolytic pathway, and knocking down PFKL dramatically repressed the expression level of Ucp1 as well as those of Prdm16, Cidea, Pgc1α, and Pparγ, which are marker genes for BAT activation. These results strongly suggested that PBA could increase energy expenditure by increasing BAT activity via the induction of PFKL. Taken together, PBA could be used as a therapeutic agent for people with obesity to prevent the development of metabolic syndrome.
ARTICLE | doi:10.20944/preprints201901.0001.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: chronic heat stress; dairy buffaloes; proteomics; adaptation mechanisms
Online: 3 January 2019 (08:32:13 CET)
Chronic heat stress (HS), aggravated by global warming, reduces the production efficiency of the buffalo dairy industry. Here, we conducted a proteomic analysis to investigate the adaptation strategies used by buffalo in response to heat stress. Seventeen differentially abundant proteins with known functions were detected using label-free quantification (LFQ), and five of these differentially expressed proteins were validated with parallel reaction monitoring (PRM). These five proteins were associated with various aspects of heat stress, including decreased heat production, increased blood oxygen delivery, and enhanced natural disease resistance. Lipase (LPL), glutathione peroxidase 3 (GPX3), cathelicidin-2 (CATHL2, LL-37), ceruloplasmin (CP), and hemoglobin subunit alpha 1 (HBA1) were shown to play cooperative roles in the tolerance of chronic HS in dairy buffalo. We found that high levels of HBA1 increased blood oxygen transport capacity. Our results increase our understanding of the adaptation of dairy buffalo to chronic heat stress.
ARTICLE | doi:10.20944/preprints201810.0089.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Metabolomics; Benchtop NMR; Biomarkers; Biomolecules; Validation; Protocol
Online: 5 December 2018 (16:14:52 CET)
Novel sensing technologies for liquid biopsies offer a promising prospect for the early detection of metabolic conditions through -omics techniques. Indeed, high-field NMR facilities are routinely used for metabolomics investigations on a range of biofluids in order to rapidly recognize unusual metabolic patterns in patients suffering from a range of diseases. However, these techniques are restricted by the prohibitively large size and cost of such facilities, suggesting a possible role for smaller, low-field NMR instruments in biofluid analysis. Herein we describe selected biomolecule validation on a low-field benchtop NMR spectrometer (60 MHz), and present an associated protocol for the analysis of biofluids on compact NMR instruments. We successfully detect common markers of diabetic control at low-to-medium concentrations through optimized experiments, including glucose (≤ 2.6 mmol./L) and acetone (25 μmol./L), and additionally in readily-accessible biofluids. We present a combined protocol for the analysis of these biofluids with low-field NMR spectrometers for metabolomics, and offer a perspective on the future of this technique appealing to point-of-care applications.
ARTICLE | doi:10.20944/preprints201811.0363.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Bone; Osteoclasts; Osteoblasts; Oat Bran; Osteoporosis
Online: 15 November 2018 (11:38:53 CET)
The number of patients with bone metabolic disorders including osteoporosis is increasing worldwide. These disorders often facilitate bone fractures, which seriously impact the patient’s quality of life and could lead to further health complications. Bone homeostasis is tightly regulated to balance bone resorption and formation. However, many anti-osteoporotic agents are broadly categorized as either bone forming or anti-resorptive, and their therapeutic use is often limited due to unwanted side effects. Therefore, safe and effective therapeutic agents are needed for osteoporosis. This study aims to clarify the bone protecting effects of oat bran water extract (OBWE) and its mode of action. OBWE inhibited RANKL-induced osteoclast differentiation by blocking c-Fos/NFATc1 through the alteration of I-κB. Furthermore, we found that OBWE enhanced BMP-2-stimulated osteoblast differentiation by the induction of Runx2 via Smad signaling molecules. In addition, the anti-osteoporotic activity of OBWE was also evaluated using an in vivo model. OBWE significantly restored ovariectomy-induced bone loss. These in vitro and in vivo results showed that OBWE has the potential to combat bone metabolic disorders including osteoporosis
REVIEW | doi:10.20944/preprints201810.0166.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: FTO; liver; gluconeogenesis; lipogenesis; glucose; insulin; type 2 diabetes; non-alcoholic fatty liver disease
Online: 9 October 2018 (03:52:49 CEST)
Common genetic variants of the fat mass and obesity associated (FTO) gene are strongly associated with obesity and type 2 diabetes. FTO is ubiquitously expressed, but appears to have tissue-specific roles. Earlier studies have focused on the role of hypothlamic FTO in the regulation of metabolism. However, it appears that FTO plays a role in the regulation of metabolism in a tissue-specific manner. Recent studies suggest that expression of hepatic FTO is regulated by metabolic signals such as nutrients and hormones and altered FTO levels in liver affects glucose and lipid metabolism. This review outlines recent findings on hepatic FTO in the regulation of metabolism, with particular focus on hepatic glucose and lipid metabolism. It is proposed that abnormal activity of hepatic signaling pathways involving FTO links metabolic impairments such as obesity, type 2 diabetes and nonalcoholic fatty liver disease (NAFLD). Therefore, a better understanding of these pathways may lead to therapeutic approaches to treat these metabolic diseases by targeting hepatic FTO. The overall goal of this review is to place FTO within the context of hepatic regulation of metabolism.
ARTICLE | doi:10.20944/preprints201808.0448.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Alzheimer’s disease; Diabetes; Diet control diet; AMPK; Tau hyperphosphorylation
Online: 8 October 2018 (15:32:11 CEST)
Alzheimer’s disease (AD) is a chronic neurodegenerative disease, and typical pathologic findings include abnormally hyperphosphorylated tau aggregation and neurofibrillary tangles. Insulin resistance and hyperglycemia have been assessed as risk factors for AD development. As the maintenance of optimal blood glucose levels is an important indicator of diabetes mellitus (DM) treatment, diet control is essential. AMPK is a crucial sensor of cellular bioenergetics for controlling anabolic and catabolic metabolism. Diet restriction to achieve euglycemia can increase AMPK activity in the liver and heart. Since AMPK is a direct regulator of tau phosphorylation, we hypothesized that strict diet control to achieve euglycemia affects tau protein phosphorylation through increased AMPK activity in the hippocampus of DM rats. To confirm this hypothesis, we generated insulin-deficient DM rats by subtotal pancreatectomy. Animals were categorized into the restriction (R) group, control (C) group and ad libitum (AL) group according to the diet. We found that tau phosphorylation was significantly increased in the R group compared with the C or AL group. AMPK activity in the R group significantly increased compared to that of the C group or AL group, as expected. Furthermore, the R group showed more critical tau pathology in the hippocampus than the other groups. These results suggest that diet control to achieve euglycemia in insulin-deficient DM conditions is harmful because of the increased possibility of AD development through increased tau phosphorylation by AMPK activation in the hippocampus. We propose that not only hyperglycemia but also euglycemia, which is beneficial in DM patients, must be considered a potential risk factor for AD development, especially when euglycemia is achieved by diet control during insulin deficiency.
ARTICLE | doi:10.20944/preprints201810.0008.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: perilipins, milk lipid globules, human breast milk, lipid content, tandem mass spectrometry, ultra-high performance liquid chromatography
Online: 1 October 2018 (12:18:46 CEST)
Objective: Lipids are secreted into milk as bilayer-coated structures: milk lipid globules (MLGs). Adipophilin (ADRP) and perilipin 3 (TIP47) are associated with MLGs in human breast milk; however, the role of these proteins in milk lipid secretion is not fully understood. The aim of the study was to investigate levels of ADRP, TIP47 and total lipid content in human breast milk, their mutual correlations and dynamics during lactation. Research Methods & Procedures: Milk samples from 22 healthy lactating women (Caucasian, Central European) were collected at five time points during lactation (1–3, 12–14, 29–30, 88–90 and 178–180 days postpartum). Mass spectrometry-based method was used for quantification of ADRP and TIP47 in the samples. The gravimetric method was used to determine milk total lipid content. Results: We observed distinctive trends in ADRP, TIP47 levels and lipid content in human breast milk during the first 6 months of lactation. We also found a significant association between lipid content and ADRP, lipid content and TIP47, and ADRP and TIP47 concentrations in breast milk at all sampling points. Moreover, we derived an equation for estimating the mean lipid content of milk based on ADRP concentration in human breast milk. Conclusions: A mass spectrometry-based method was developed for quantifying ADRP and TIP47 in human breast milk. Strong mutual correlations were found between ADRP, TIP47 and total lipid content in human breast milk.
ARTICLE | doi:10.20944/preprints201807.0219.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: High-Fat Diet, Dietary Supplement, Oxidative stress, Inflammation, Neurodegeneration.
Online: 12 July 2018 (15:45:18 CEST)
Obesity and metabolic disorders can be risk factors for the onset and development of neurodegenerative diseases. The aim of the present study was to investigate the protective effects on dysmetabolism and neurodegeneration of a natural dietary supplement (NDS), containing Curcuma longa, silymarin, guggul, chlorogenic acid and inulin, on the brains of high fat diet (HFD)-fed mice. A decreased expression of FACL-4, CerS-1 and CerS-4, reduced cholesterol concentration, increased IR expression and insulin signaling activation, were found in brains of NDS-treated HFD mice, suggesting that NDS is able to prevent brain lipid accumulation and central insulin resistance. In the brains of NDS-treated HFD mice, the levels of RNS, ROS and lipid peroxidation, the expression of p-ERK, H-Oxy, i-NOS, HSP60, NF-kB, GFAP, IL-1β, IL-6, and CD4 positive cell infiltration were lower than in untreated HFD mice, suggesting antioxidant and anti-inflammatory effects of NDS. The decreased expression of p-ERK and GFAP in NDS-treated HFD mice was confirmed by immunofluorescence. Lastly, a lower number of apoptotic nuclei was found in cortical sections of NDS-treated HFD. All these data indicate that NDS exerts neuroprotective effects in HFD mice by reducing brain fat accumulation, oxidative stress and inflammation and improving brain insulin resistance.
REVIEW | doi:10.20944/preprints201807.0143.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Aromatic hydroxy metabolites; arenolic drug metabolites; metabolic O-dealkylation; metabolic aromatic ring hydroxylation; primary and auxiliary pharmacophores; auxophores; metabolic modification of drug activity
Online: 9 July 2018 (13:28:16 CEST)
Drug functionalization through formation of hydrophilic groups is the norm in phase I metabolism of drugs for modification of drug action. The reactions involved are mainly oxidative catalyzed mostly by CYP isoenzymes. The benzene ring, as phenyl or fused with other rings, is the most common hydrophobic pharmacophoric moiety in drug molecules. On the other hand the alkoxy group (mainly methoxy) bonded to the benzene ring assumes an important and sometimes essential pharmacophoric status in some drug classes. Upon metabolic oxidation, both moieties, i.e. the benzene ring and the alkoxy group, produce hydroxy groups; the products are arenolic in nature. Through a pharmacokinetic effect, the hydroxy group enhances the water solubility and elimination of the metabolite with the consequent termination of drug action. However, through hydrogen bonding, the hydroxy group may modify the pharmacodynamics of the interaction of the metabolite with the site of parent drug action (i.e. the receptor). Accordingly, the expected pharmacologic outcome will be enhancement, retaining, attenuation, or loss of activity of the metabolite relative to the parent drug. All the above issues have been presented and discussed in this review using selected members of different classes of drugs with inferences regarding mechanisms, drug design and drug development.
ARTICLE | doi:10.20944/preprints201807.0065.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: hypothalamus; insulin resistance; inflammation; docosahexaenoic acid; PI3K inhibitor; AKT
Online: 4 July 2018 (09:58:03 CEST)
Saturated fatty acids are implicated in the development of metabolic diseases, including obesity and type 2 diabetes. There is evidence, however, that polyunsaturated fatty acids can counteract the pathogenic effects of saturated fatty acids. To gain insight into the early molecular mechanisms by which fatty acids influence hypothalamic inflammation and insulin resistance, we performed time-course experiments in a hypothalamic cell line, using different durations of treatment with the saturated fatty acid palmitate, and the omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA). Western blot analysis revealed that palmitate elevated the protein levels of phospho(p)AKT in a time-dependent manner. This effect seems involved in the pathogenicity of palmitate, as temporary inhibition of the PI3K/AKT pathway by selective PI3K inhibitors prevented palmitate-induced insulin resistance. Similarly to palmitate, DHA also increased levels of pAKT, but to a weaker extent. Co-administration of DHA with palmitate decreased pAKT close to the basal level after 8 h, and prevented palmitate-induced insulin resistance after 12 h. Measurement of the inflammatory markers pJNK and pNFκB-p65 revealed tonic elevation of both markers in the presence of palmitate alone. DHA alone transiently induced elevation of pJNK, returning to basal levels by 12 h treatment. Co-administration of DHA with palmitate prevented palmitate-induced inflammation after 12 h, but not at earlier time points.
ARTICLE | doi:10.20944/preprints201806.0193.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: aronia; ginseng; mushroom; pancreatectomy; type 2 diabetes; gut microbiome; insulin secretion
Online: 12 June 2018 (13:01:30 CEST)
The combination of freeze-dried aronia, red ginseng, ultraviolet-irradiated shiitake mushroom and natokinase (AGM; 3.4: 4.1: 2.4: 0.1) was examined to evaluate its effects on insulin resistance, insulin secretion and gut microbiome in a non-obese type 2 diabetic animal model. Pancreatectomized (Px) rats were provided high fat diets supplemented with either of 1) 0.5 g AGM (AGM-L), 2) 1 g AGM (AGM-H), 3) 1 g dextrin (control), or 4) 1g dextrin with 120 mg metformin (positive-control) per kg body weight for 12 weeks. AGM (1 g) contained 6.22 mg cyanidin-3-galactose, 2.5 mg ginsenoside Rg3 and 0.6 mg β-glucan. Px rats had decreased bone mineral density in the lumbar spine and femur and lean body mass in the hip and leg compared to the normal-control and AGM-L and AGM-H prevented the decrease. Visceral fat mass was lower in the control group than the normal-control group and its decrease was smaller by AGM-L and AGM-H. HOMA-IR was lower in descending order of the control, positive-control, AGM-L, AGM-H and normal-control groups. Glucose tolerance was deteriorated in the control group and it was improved by AGM-L and AGM-H more than in the positive-control group. Glucose tolerance is associated with insulin resistance and insulin secretion. Insulin tolerance indicated insulin resistance was highly impaired in diabetic rats, but it was improved in the ascending order of the positive-control, AGM-L and AGM-H. Insulin secretion capacity, measured by hyperglycemic clamp, was much lower in the control group than the normal-control group and it was improved in the ascending order of the positive-control, AGM-L and AGM-H. Diabetes modulated the composition of gut microbiome and AMG prevented the modulation of gut microbiome. In conclusion, AGM improved glucose metabolism by potentiating insulin secretion and reducing insulin resistance in insulin deficient type 2 diabetic rats. The improvement of diabetic status alleviated body composition changes and prevented changes of gut microbiome composition.
ARTICLE | doi:10.20944/preprints201805.0256.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Implantation failure; Bisphenol A; 4-tert-octylphenol; calcium channel
Online: 18 May 2018 (07:38:04 CEST)
Miscarriage due to blastocyst implantation failure occurs in up to two-thirds of all miscarriage cases in human. The calcium ion has been shown to be involved in many cellular signal transduction pathways as well as in the regulation of cell adhesion, which is necessary for the embryo implantation process. Exposure to endocrine-disrupting chemicals (EDs) during early gestation results in disruption of intrauterine implantation and uterine reception, leading to implantation failure. In this study, ovarian estrogen (E2), bisphenol A (BPA), or 4-tert-octylphenol (OP), with or without ICI 182,780 (ICI) were injected subcutaneously from gestation day 1 to gestation day 3 post-coitus. The expression levels of the calcium transport genes were assessed in maternal uteri and implantation sites. The number of implantation sites was significantly low in the OP group, and implantation sites were absent in the E2 and EDs+ICI groups. There were different calcium transient transport channel expression levels in uterus and implantation site samples. The levels of TRPV5 and TRPV6 gene expression were significantly increased by EDs with/without ICI treatment in uterus. Whereas, TRPV5 and TRPV6 gene expression were significantly lower in implantation sites samples. NCX1 and PMCA1 mRNA levels were significantly decreased by OP and BPA in the implantation site samples. Compared to vehicle treatment in uterus, both the MUC1 mRNA and protein levels were markedly high in all but the BPA group. Taken together, these results suggest that both BPA and OP can impair embryo implantation through alteration of calcium transport gene expressions and by affecting uterine receptivity.
ARTICLE | doi:10.20944/preprints201804.0049.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: garcinia mangostana; inflammation; insulin resistance; metabolic syndrome; diabetes; xanthones; mangostin; phytotherapy; dietary supplements
Online: 4 April 2018 (06:19:44 CEST)
Insulin resistance is the most important underlying cause of obesity and type 2 Diabetes (T2DM), and insulin sensitizing treatments have proved effective in preventing diabetes and inducing weight loss. Obesity and T2DM are also associated with increased inflammation. Mangosteen is a tropical tree, whose fruits, widely known for their antioxidant properties, have been recently suggested having a possible further role in the treatment of obesity and T2DM. The objective of this pilot study has been to evaluate safety, compliance and efficacy of mangosteen on insulin resistance, weight management, and inflammatory status in obese female patients with insulin resistance. 22 patients were randomized 1:1 to behavioral therapy alone or behavioral therapy and mangosteen and 20 completed the 26-week study. The mangosteen group reported a significant improvement in insulin sensitivity (HOmeostatic Model Assessment-Insulin Resistance, HOMA-IR -53.22% vs -15.23%, p=.0037), and a trend decrease in inflammation markers serum levels, together with trend greater weight loss and trend increased HDL levels. No side effect attributable to treatment was reported. Given the positive preliminary results we report and the excellent safety profile, we suggest a possible role of mangosteen in the treatment of obesity, insulin resistance and inflammation.
ARTICLE | doi:10.20944/preprints201804.0033.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: cordycepin; adenosine A1 receptor; prolactin; anti-obesity
Online: 3 April 2018 (07:53:24 CEST)
Cordycepin is an extract from the insect fungus Cordyceps. militaris, which is a traditional medicine with various biological function. In previous studies, cordycepin had been reported with excellent anti-obesity effect, but the mechanism is unclear. A large quantity of evidences showed that prolactin plays an important part in body weight regulation, hyperprolactinemia can promote appetite and accelerate fat deposition. In this study, we explored the molecular mechanism of the anti-obesity effect of cordycepin by reducing prolactin release via an adenosine A1 receptor. In vivo, obese rats model was induced by high fat diet for 5 weeks, the serum and liver lipids coupling with serum prolactin were reduced by treatment of cordycepin, the results suggested that cordycepin is a potential drug for therapying obesity which could be related with prolactin. In vitro, cordycepin could inhibit prolactin secretion in GH3 cells via upregulating the expression of adenosine A1 receptor, the inhibition effect could be blocked by an antagonist of adenosine receptor A1 DPDPX, prolactin induced the upregulation of lipogenesis genes PRLR, and P-JAK2 in 3T3-L1 cells. Intriguingly, cordycepin would down-regulate the expression of prolactin receptor (PRLR). Thus, we concluded that cordycepin modulate body weight by reducing prolactin release via an adenosine A1 receptor.
REVIEW | doi:10.20944/preprints201712.0023.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: physical exercise; irisin; neurodegeneration; aging; Alzheimer’s disease
Online: 11 February 2018 (04:28:07 CET)
Irisin, a skeletal muscle-secreted myokine, produced in response to physical exercise, has protective functions in both the central and the peripheral nervous systems, including the regulation of brain-derived neurotrophic factors and modification of telomere length. Such beneficial effects may inhibit or delay the emergence of neurodegenerative diseases, including Alzheimer’s disease (AD). This review is based on the hypothesis that irisin produced by physical exercise helps control AD progression. Herein, we describe the physiology of irisin and its potential role in delaying or preventing AD. Although current and ongoing studies on irisin show promising results, further research is required to clarify its potential as a meaningful therapeutic target for treating human diseases.
ARTICLE | doi:10.20944/preprints201801.0210.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: fructose; intestinal microbiota; short-chain fatty acids; metabolic profiling
Online: 23 January 2018 (05:31:27 CET)
Increased sugar intake is implicated in Type-2 diabetes and fatty liver disease. Mechanisms by which glucose and fructose components promote these conditions are unclear. We hypothesize that alterations in intestinal metabolite and microbiota profiles specific to each monosaccharide are involved. Two groups of six adult C57BL/6 mice were fed for 10-weeks with a diet where either glucose or fructose was the sole carbohydrate component (G and F, respectively). A third group was fed with normal chow (N). Fecal metabolites were profiled every 2-weeks by 1H NMR and microbial composition was analysed by real-time PCR (qPCR). Glucose tolerance was also periodically assessed. N, G and F mice had similar weight gains and glucose tolerance. Multivariate analysis of NMR profiles indicated that F mice were separated from both N and G, with decreased butyrate and glutamate and increased fructose, succinate, taurine, tyrosine and xylose. Compared to N and G, F mice showed a shift in microbe populations from gram-positive Lactobacillus spp. to gram-negative Enterobacteria species. Substitution of normal chow carbohydrate mixture by either pure glucose or fructose for 10 weeks did not alter adiposity or glucose tolerance. However, F G and N mice generated distinctive fecal metabolite signatures with incomplete fructose absorption as a dominant feature of F mice.
REVIEW | doi:10.20944/preprints201709.0040.v2
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Gut microbiota; obesity; insulin resistance, NAFLD; probiotic; prebiotic; symbiotic
Online: 6 October 2017 (16:15:42 CEST)
Gut microbiota play critical roles in development of obese-related metabolic diseases such as nonalcoholic fatty liver disease (NAFLD), type 2 diabetes, and insulin resistance, which highlighted the potential of gut microbiota-targeted therapies on these diseases. There are various ways that can manipulate gut microbiota including probiotics, prebiotics, synbiotics, antibiotics and some active components from herbal medicines. In this review, we first reviewed the main roles of gut microbiota in mediating the development of NAFLD, and the advances in gut microbiota-targeted therapies on NAFLD in both the experimental and clinical studies, as well as the conclusions on the prospect of gut microbiota-targeted therapies in the future.
ARTICLE | doi:10.20944/preprints201705.0174.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: steroid; metabolism; anti-inflammatory drug; inhibition
Online: 24 May 2017 (08:25:26 CEST)
In vitro studies show that diclofenac inhibits enzymatic steroid glucuronidation. This study was designed to investigate the influence of diclofenac on the excretion of stanozolol and 3'-hydroxystanozolol via analyses in hair, blood and urine in vivo in a rat study. Brown Norway rats were administered with stanozolol (weeks 1-3) and diclofenac (weeks 1-6). Weekly assessment of steroid levels in hair was complemented with spot urine and serum tests. Levels of both stanozolol and 3'-hydroxystanozolol steadily increased in hair during stanozolol treatment and decreased post-treatment, but remained readily detectable for 6 weeks. In contrast, compared to control rats, diclofenac significantly reduced urinary excretion of 3’-hydroxystanozolol which was undetectable in most samples. This is the first report of diclofenac altering steroid metabolism in vivo, detrimentally affecting detection in urine, but not in hair which holds considerable advantages over urinalysis for anti-doping tests.
REVIEW | doi:10.20944/preprints201704.0059.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Keywords: vitamin D deficiency; diabetic retinopathy; meta-analysis.
Online: 11 April 2017 (06:16:22 CEST)
Background: Diabetic retinopathy (DR) is one of the most prominent pathological microvascular complications in diabetes. A series of studies reported that vitamin D deficiency was associated with increased prevalence of retinopathy in diabetic patients but the results were inconsistent. In this study we focused on evaluating the relationship between vitamin D deficiency and DR by conducting a meta-analysis of observational studies. Methods: Systematic computerized searches were performed in PubMed, MEDLINE, and the Cochrane Library for relevant original articles till November 20, 2016. The pooled odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated to assess the associated value of vitamin D deficiency to the risk of DR. 9 studies including 6332 participants were subjected to final analysis. Results: The results indicated that vitamin D deficiency increases the risk of DR (OR = 1.57, 95% CI 1.32-1.87) with a little heterogeneity (I2 = 23%). In addition, the subgroup analysis demonstrated that there were obvious heterogeneities in T2DM (I2 = 47.8%). Sensitivity analysis showed that the results were relatively stable and reliable. Conclusion: our meta-analysis demonstrated that vitamin D deficiency could increase the risk of DR.
ARTICLE | doi:10.20944/preprints201701.0088.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: adipose derived stem cell (ASC); regenerative medicine; embryonic stem cell marker network
Online: 19 January 2017 (10:59:11 CET)
The stromal vascular cell fraction (SVF) of visceral and subcutaneous adipose tissue (VAT and SAT) has increasingly come into focus in stem cell research, since these compartments represent a rich source of multipotent adipose-derived stem cells (ASCs). ASCs exhibit a self- renewal potential and differentiation capacity. Our aim was to study the different expression of embryonic stem cell markers NANOG, SOX2 and OCT3/4 and to evaluate if there exists a hierarchal role in this network in ASCs derived from both SAT and VAT. ASCs were isolated from SAT and VAT biopsies of 72 consenting patients (23 men, 47 women; age 45 ± 10; BMI between 25 and 30 range) undergoing elective open-abdominal surgery. Sphere-forming capability was evaluated by plating cells in low adhesion plastic. Stem cell markers CD90 and CD105 were analyzed by flow cytometry and stem cell transcription factors NANOG, SOX2 and OCT3/4 were detected by immunoblotting and Real-Time PCR. NANOG, SOX2 and OCT3/4 interplay was explored by gene silencing. ASCs from VAT and SAT confirmed their mesenchymal stem cell (MSC) phenotype expressing the specific MSC markers CD90 and CD105 and NANOG, SOX2 and OCT3/4. NANOG silencing induced a significant OCT 3/4 (70% ± 0.05) and SOX2 (75% ± 0.03) down-regulation whereas SOX2 silencing did not affect NANOG gene expression. Adipose tissue is an important source of MSC, and siRNA experiments endorse a hierarchical role of NANOG in the complex transcription network that regulates pluripotency and plasticity.