ARTICLE | doi:10.20944/preprints202207.0361.v1
Subject: Medicine And Pharmacology, Anesthesiology And Pain Medicine Keywords: PSPS; FBSS; SCS; surgical lead; SCS implantation; MAST (for Minimal Access Spine Technologies); TCIVA (for Target Controlled Intra-Veinous Anesthesia); composite score; pain mapping; neuropathic pain; chronic pain; quality of life; anesthesia; hypnosis
Online: 25 July 2022 (08:34:26 CEST)
Spinal Cord Stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in Persistent Spinal Pain Syndrome-Type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that Awake Anesthesia (AA), consisting in Target Controlled Intra-Veinous Anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with Minimal Invasive Surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or General Anesthesia (MISGA group), or by Laminectomy under General Anesthesia (LGA group). All in all, MISAA appears to show significantly better performance in terms of patient pain coverage, as well as improved secondary outcomes. One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.
ARTICLE | doi:10.20944/preprints201806.0177.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: cancer; lung cancer; selectivity; Tetraclinis articulata (Vahl) Mast., Cupressaceae
Online: 12 June 2018 (09:02:50 CEST)
In our continuous search for selective anticancer treatments, we have screened 65 extracts from 45 plants collected in several areas of Western Andalusia (Spain) for cytotoxic activity against lung cancer cells and lung normal cells. Active extracts were also tested against 11 cell lines from other tissues. An extract from the leaves of Tetraclinis articulata (Vahl) Mast. (Cupressaceae) showed a marked cytotoxicity (IC50 = 0.37 ± 0.03 µg/mL) and selectivity (selectivity index = 378.3) against the lung cancer cells; cisplatin, 5-fluorouracil and an extract from the leaves of Taxus baccata L. (Taxaceae) were less cytotoxic and selective.
REVIEW | doi:10.20944/preprints202305.0031.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: molecular hydrogen; reactive oxygen intermediates; mast cells; secretome; specific mast cell proteases; local tissue microenvironment; inflammation
Online: 1 May 2023 (11:54:37 CEST)
Knowledge of the biological effects of molecular hydrogen (H2), hydrogen gas, is constantly expanding giving a reason for optimism for several healthcare practitioners regarding management of multiple diseases, including socially significant ones. However, mechanisms underlying the biological effects of H2 are still being actively argued. In this review, we focus on mast cells as a potential target for H2 at the level of a specific tissue microenvironment. H2 regulates processing of pro-inflammatory components of the mast cell secretome and their entry into the extracellular matrix; this can significantly affect the state of the integrated-buffer metabolic environment and the structure of the immune landscape of the local tissue microenvironment. The analysis performed highlights several potential mechanisms for developing the biological effects of H2 and offers great opportunities for translating the obtained findings into clinical practice.
ARTICLE | doi:10.20944/preprints201910.0330.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: mast cell; il-9; chymase; histamine; atp
Online: 29 October 2019 (10:23:19 CET)
Accumulating evidence suggests that mast cells should play critical roles in disruption and maintenance of intestinal homeostasis, although it remains unknown how they affect local microenvironment. Interleukin-9 (IL-9) was found to play critical roles in intestinal mast cell accumulation induced in various pathological conditions, such as parasite infection and oral allergen-induced anaphylaxis. Newly recruited intestinal mast cells trigger inflammatory responses and damage epithelial integrity through release of a wide variety of mediators including mast cell proteases. We established a novel culture model (mucosal mast cell-like cultured mast cells, MMC-like MCs), in which murine IL-3-dependent bone marrow-derived cultured mast cells (BMMCs) were further cultured in the presence of stem cell factor and IL-9. In MMC-like MCs, drastic up-regulation of Mcpt1 and Mcpt2 was found. Although histamine storage and tryptase activity were significantly downregulated in the presence of SCF and IL-9, it was entirely reversed when mast cells were co-cultured with a murine fibroblastic cell line, Swiss 3T3. MMC-like MCs underwent degranulation upon IgE-mediated antigen stimulation, which was found to less sensitive to lower concentrations of IgE in comparison with BMMCs. This model might be useful for investigation of the spatiotemporal changes of newly recruited intestinal mast cells.
REVIEW | doi:10.20944/preprints202102.0015.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: mast cells; mastocytosis; mediator-related symptoms; anaphylaxis; children
Online: 1 February 2021 (11:36:31 CET)
Mastocytosis is characterized by pathological accumulation of mast cells (MC) in various organs. In these patients, MC may degranulate and thereby contribute to clinical symptoms, especially when a concomitant allergy is present. However, MC activation can not only be induced by high-affinity receptors for IgE, but also by anaphylatoxins, neuropeptides, IgG immune complexes, complement-components, drugs, products of bacteria or parasites, as well as physical factors such as heat, cold, vibration, stress, sun, or physical effort. Symptoms due to mediators released by activated MC may develop in adults suffering from systemic mastocytosis, but also evolve in children who usually have cutaneous mastocytosis (CM). Clinically, CM is otherwise characterized by typical brown, maculopapular skin lesions or mastocytoma associated with a positive Darier’s sign. Pruritus and flushing are common and blistering may also be recorded, especially in diffuse CM (DCM). Pediatric patients with mastocytosis may also have gastrointestinal, respiratory, and neurologic complaints. Although anaphylaxis is not a typical finding, pediatric patients with massive skin involvement and high tryptase levels have a relatively high risk to develop anaphylaxis. This paper reviews MC mediator-related symptoms and anaphylaxis in children with mastocytosis, with special emphasis on risk factors, triggers, and management.
REVIEW | doi:10.20944/preprints202011.0016.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mast cells; adaptive immunity; dendritic cells; T cells
Online: 2 November 2020 (10:27:12 CET)
Although Mast cells are known as key drivers of type I allergic reactions, there is increasing evidence for their critical role in host defense. MCs do not only play an important role in initiating innate immune responses, but also influence the onset, kinetic and amplitude of the adaptive arm of immunity, or fine-tune the mode of the adaptive reaction. Intriguingly, MCs have been shown to affect T cell activation by direct interaction or indirectly by modifying properties of antigen-presenting cells, and can even modulate lymph node-borne adaptive responses remotely from the periphery. In this review, we provide a summary of recent findings that explain how MCs act as a link between the innate and the adaptive immunity, all the way from sensing inflammatory insult to orchestrating the final outcome of the immune response.
ARTICLE | doi:10.20944/preprints202311.1750.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: mast cells; granule proteases; cathepsin G; tryptase; chymase; Fc receptors; IgE; prostaglandins; leukotrienes; heparin
Online: 28 November 2023 (10:18:36 CET)
Studies of mast cell biology is dependent on relevant and validated in vitro models. We here present detailed information concerning the phenotype of both freshly isolated human skin mast cells (MCs), and of in vitro cultures of these cells that was obtained by analyzing their total transcriptome. Transcript levels of MC-related granule proteins and transcription factors were found to be remarkably stable over a 3-week culture period. Relatively modest changes were also seen for important cell surface receptors including the high affinity receptor for IgE, FCER1A, the low affinity receptor for IgG, FCGR2A, and the receptor for stem cell factor, KIT. FCGR2A was the only Fc receptor for IgG expressed by these cells. Comparisons of the present transcriptome against previously reported transcriptomes of mouse peritoneal MCs and mouse bone marrow derived MCs (BMMCs) revealed both similarities and major differences. Strikingly, cathepsin G was the most highly expressed granule protease in human skin MCs, in contrast to the almost total absent of this protease in both mouse MCs. Transcript levels for the majority of cell surface receptors were also very low compared to the granule proteases in both mouse and human MCs, with a difference of almost two orders of magnitude. An almost total absence of T cell granzymes was observed in human skin MCs, indicating that granzymes have no or only a minor role in human MC biology. Ex vivo skin MCs expressed high levels of selective immediate early genes and transcripts of heat-shock proteins. In validation experiments, we determined that this expression was an inherent property of the cells and not the result of the isolation process. Three to four weeks in culture results in an induction of cell growth related genes accompanying their expansion by 6-10-fold, which increases the number of cells for in vitro experiments. Collectively, we show that cultured human skin MCs resemble their ex vivo equivalents in many respects and are a more relevant in vitro model compared to mouse BMMCs for studies of MC biology, in particular human MC biology.
ARTICLE | doi:10.20944/preprints201901.0003.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: mast cell; dexamethasone; trimeric G protein; Mrgpr; skin; inflammation
Online: 3 January 2019 (08:55:29 CET)
Steroidal anti-inflammatory drugs are widely used for treatment of chronic cutaneous inflammation, such as atopic dermatitis, although it remains unknown how they modulate cutaneous mast cell functions. Murine connective tissue-type mast cells, which were sensitive to mast cell secretagogues, such as compound 48/80 and substance P, were generated by co-culture of bone marrow-derived mast cells with Swiss 3T3 fibroblasts in the presence of stem cell factor. This process was accompanied by up-regulation of a subunit of a trimeric G protein, Gi1, and several Mas-related G protein-coupled receptor (Mrgpr) subtypes. Secretagogue-induced degranulation and up-regulation of these genes were suppressed when they were cultured in the presence of a synthetic glucocorticoid, dexamethasone. The profiles of granule constituents were drastically altered by dexamethasone. Several Mrgpr subtypes were found to be expressed in the cutaneous tissues and their expression levels were decreased in response to topical application of dexamethasone. The numbers of degranulated cutaneous mast cells in response to compound 48/80 were decreased in mice treated with dexamethasone. These results suggest that mast cell-mediated IgE-independent cutaneous inflammation could be suppressed by steroidal anti-inflammatory drugs through down-regulation of Gai1 and several Mrgpr subtypes in mast cells.
ARTICLE | doi:10.20944/preprints202311.0194.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: Urticaria; SARS-CoV-2 infection; COVID-19 pandemic; mast cells
Online: 3 November 2023 (11:12:59 CET)
Abstract: The COVID-19 pandemic significantly disrupted global healthcare systems. The impacts of SARS-CoV-2 infection on urticaria and its management are unknown. To collect information about patients with urticaria infected with SARS-CoV-2 and to investigate the impact of SARS-CoV-2 infection on urticaria severity, course, and treatment to better support recovery. This was a questionnaire-based study of patients with urticaria infected with SARS-CoV-2. Changes in urticaria severity (measured with the urticaria activity score (UAS)), course, and treatment were assessed before, during, and after SARS-CoV-2 infection. Mean (± SD) UAS scores were 5.17 ± 1.67, 4.23 ± 1.98, and 4.37 ± 1.93 before, during, and after SARS-CoV-2 infection, respectively (F = 8.839, p < 0.01). The median (IQR) wheal score was 0.464 (0.464, 0.763), 0.464 (0.138, 0.763), and 0.464 (0.138, 0.763) before, during, and after infection, respectively (Kruskal-Wallis H-test, H=12.230, p = 0.02). The median (IQR) pruritus score was 0.695 (0.395, 0.695), 0.394 (0.123, 0.695), and 0.394 (0.123, 0.695) before, during, and after infection, respectively (Kruskal-Wallis H-test, H = 21.001, p < 0.01). Within the limitations of a questionnaire study, urticaria appears to improve during SARS-CoV-2 infection, worsens slightly after recovery, and the frequency of Western medicine use increases.
ARTICLE | doi:10.20944/preprints202111.0376.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Mast cells; Leishmania mexicana; sand fly salivary proteins; sexual hormones
Online: 22 November 2021 (10:51:24 CET)
Mast cells (MCs) play a crucial role during infections with Leishmania, that is transmitted through the bite of an infected sand fly that injects saliva together with the parasite. Sand fly saliva is a complex fluid that modulates the host immune response. In addition, hormonal factors modulate the host immune response, impacting the susceptibility to infections. Thus, to assess the impact of androgens and salivary proteins of sand fly vectors on the mast cell (MC) response to Leishmania infections, we infected orchiectomized male mice with the parasite in the presence or absence of sand fly salivary proteins and analyzed the inflammatory response of MCs. Our results showed a differential MC response to the parasite and to vector salivary proteins in mice deprived of gonadal hormones, as compared to sham-operated mice. Orchidectomy induced a different pattern of activation in MC of animals infected with Leishmania and vector-salivary proteins. Our results show that during Leishmania infection, androgens modulate the innate immunity response against the parasite and salivary proteins of the sand fly vector.
REVIEW | doi:10.20944/preprints202104.0036.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mast cells; innate immunity; host defense; skin; inflammatory skin disorders
Online: 1 April 2021 (17:44:17 CEST)
Mast cells (MCs) are best known as key effector cells of immediate type allergic reactions that may even culminate in life-threatening anaphylactic shock syndromes. However, strategically positioned at host-environment interfaces and equipped with a plethora of receptors, MCs also play an important role in the first line defense against pathogens. Their main characteristic, the huge amount of preformed pro-inflammatory mediators embedded in secretory granules, allow for a rapid response and initiation of further immune effector cell recruitment. The same mechanism, however, may account for detrimental overshooting responses. MCs are not only detrimental in MC-driven diseases, but also responsible for disease exacerbation in other inflammatory disorders. Focusing on the skin as the largest immune organ, we herein review both beneficial and detrimental functions of skin MCs all the way from skin barrier integrity via host defense mechanisms to MC-driven inflammatory skin disorders. Moreover, we emphasize the importance of IgE-independent pathways of MC activation and their role in sustained chronic skin inflammation and disease exacerbation.
REVIEW | doi:10.20944/preprints201910.0331.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: allergic reaction; CD158d; IgE receptor; KIR2DL4; KIT; mast cell; pregnancy
Online: 29 October 2019 (10:26:12 CET)
Killer immunoglobulin-like receptor (KIR) 2DL4 (CD158d) was previously thought to be a human NK-cell-specific protein but its expression has also been demonstrated in human mast cells. Mast cells are involved in allergic reactions via their KIT-mediated and IgE receptor-mediated responses. We recently detected the expression of KIR2DL4 in human cultured mast cells established from peripheral blood derived from healthy volunteers (PB-mast), a human mast cell line (LAD2), and non-neoplastic mast cells, including pathological specimens. An agonistic antibody against KIR2DL4 negatively regulates the KIT- and IgE-receptor-mediated responses of PB-mast and LAD2 cells. In addition, agonistic antibodies and human leukocyte antigen (HLA)-G, a natural ligand for KIR2DL4, induce the secretion from these cells of leukemia inhibitory factor and serine proteases, which have been implicated in pregnancy establishment and cancer metastasis. Therefore, KIR2DL4 stimulation with agonistic antibodies and recombinant HLA-G protein may enhance both processes, in addition to suppressing mast-cell-mediated allergic reactions.
ARTICLE | doi:10.20944/preprints201904.0246.v2
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Oxytocin, Oxytocin Receptor, Autism, Nepsys Scale, MAST Immune System Disease, Dendritic Spines, Magnocellular Neurons, Desensitization, Labor, Down Regulation
Online: 23 April 2019 (11:12:19 CEST)
This paper develops mathematical models examining possible roles of oxytocin and oxytocin receptors in the development of autism. This is done by demonstrating that mathematical operations on normalized data from the Stanford study (K.J. Parker, 2016), which establishes a correspondence between severity of autism in children and their oxytocin blood levels, generates a graph that is the same as the graph of mathematical operations on a normalized theoretical model for the severity of autism. This procedure establishes the validity of the theoretical model and the significance of oxytocin receptors in autism. A steady-state model follows, explaining the constant baseline concentrations of oxytocin observed in the cerebral spinal fluid and blood in terms of the neuromodulation by oxytocin of oxytocin receptors on the magnocellular neurons that produce oxytocin in nuclei in the hypothalamus. The implications of these models for possible roles of oxytocin and oxytocin receptors in autism is considered for several unrelated conditions that may be associated with autism. These are: oxytocin receptor desensitization and down-regulation as factors during labor in offspring autism development; reductions in the oxytocin receptor numbers in the fixed oxytocin receptor expression that occurs before birth; MAST Immune System disease; and the excess number of dendritic spines from lack of pruning observed in brains of autistic people. Research into the feasibility of generating magnocellular neurons and other neurons from adult stem cells is suggested as a way of doing invitro studies of oxytocin and oxytocin receptors to assess the validity of theories presented in this paper.
ARTICLE | doi:10.20944/preprints202308.0890.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Space Flight; Mast Cells; Tryptase; Chymase; Mongolian Gerbils; the Digestive System
Online: 11 August 2023 (04:54:59 CEST)
Abstract: Mast cell (MC) specific proteases are of particular interest for space biology and medicine due to their biological activity in regulating targets of a specific tissue microenvironment. MC tryptase and chymase obtain the ability to remodel connective tissue through direct and indirect mechanisms. Yet, MC specific protease expression under space flight conditions has not been adequately investigated. Using immunohistochemical stainings, we analyzed in this study the protease profile of the jejunal, gastric and hepatic MC populations in three groups of Mongolian gerbils - vivarium control, synchronous experiment, and 12-day orbital flight on the Foton-M3 spacecraft, - and in two groups - vivarium control and anti-orthostatic suspension - included in the experiment simulating effects of weightlessness in the ground-based conditions. After a space flight, there was a decreased number of MCs in the studied organs combined with an increased proportion of chymase-positive MCs and MCs with a simultaneous content of tryptase and chymase; the secretion of specific proteases into the extracellular matrix increased. These changes in the expression of proteases were observed both in the mucosal and connective tissue MC subpopulations of the stomach and jejunum. Notably, the relative content of tryptase-positive MCs in the studied organs of the digestive system decreased. Space flight conditions simulated in the synchronous experiment caused no similar significant changes in the protease profile of MC populations. The space flight conditions resulted in an increased chymase expression combined with a decreased total number of protease-positive MCs apparently due to participating in the processes of extracellular matrix remodeling and regulating the state of the cardiovascular system.
REVIEW | doi:10.20944/preprints202302.0148.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: Neuropeptide; Inflammation; Immunity; Mast cell: Pro-inflammatory cytokines; Anti-inflammatory cytokines
Online: 8 February 2023 (11:33:15 CET)
Mass cells (MCs) are tissue cells that are derived from bone marrow stem cells that contribute to allergic reactions, inflammatory diseases, innate and adaptive immunity, autoimmunity, and mental disorders. MCs located near the meninges communicate with microglia through the production of mediators such as histamine and tryptase, but also through the secretion of IL-1, IL-6 and TNF, which can create pathological effects in the brain. Preformed chemical mediators of inflammation and tumor necrosis factor (TNF) are rapidly released from the granules of MCs, the only immune cells capable of storing the cytokine TNF, although it can also be produced later through mRNA. The role of MCs in nervous system diseases has been extensively studied and reported in scientific literature and is of great clinical interest. However, many of the published articles concern studies on animals (mainly rats or mice) and not on humans. MCs are known to interact with neuropeptides that mediate endothelial cell activation, resulting in central nervous system (CNS) inflammatory disorders. In the brain, MCs interact with neurons causing neuronal excitation with the production of neuropeptides and the release of inflammatory mediators such as cytokines and chemokines. This article explores the current understanding of MC activation by neuropeptides and the role of pro-inflammatory cytokines, suggesting a therapeutic effect of the anti-inflammatory cytokines IL-37 and IL-38.
REVIEW | doi:10.20944/preprints202101.0520.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: mast cell; psoriasis; inflammation; cytokine; Il-37; IL-38; IL-1Ra
Online: 25 January 2021 (15:57:19 CET)
Psoriasis (PS) is an autoimmune skin disease mediated by immune cells that typically presents inflammatory erythematous plaques, and it is associated with many comorbidities. PS exhibits excessive keratinocyte proliferation, and a high number of immune cells including macrophages, neutrophils, Th1 and Th17 lymphocytes, and mast cells (MCs). MCs are of hematopoietic origin, derived from bone marrow cells, which migrate, mature and reside in vascularized tissues. They can be activated by antigen provoking overexpression of pro-inflammatory cytokines and release a number of mediators including interleukin (IL)-1 and IL-33. IL-1, released by activated keratinocytes and MCs, stimulates skin macrophage to release IL-36, a powerful pro-inflammatory IL-1 family member. IL-36 mediates both innate and adaptive immunity, including chronic pro-inflammatory diseases such as psoriasis. Suppressing IL-36 results in a noticeable improvement in the treatment of psoriasis. IL-36 is inhibited by IL-36Ra which binds on to IL-36 receptor ligand, but suppression can also occur by binding IL-38 to the IL-36R receptor. IL-38 specifically binds only to IL-36R and inhibits human mononuclear cells stimulated with IL-36 in vitro, sharing the effect with IL-36Ra. Here, we report that inflammation in psoriasis is mediated by IL-1 generated by MCs, a process that activates macrophages to secrete pro-inflammatory IL-36 inhibited by IL-38. In this article we confirm that IL-38 and IL-37 cytokines emerge as inhibitors of inflammation in psoriasis and hold promise of an innovative therapeutic tool.
ARTICLE | doi:10.20944/preprints201708.0060.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Passiflora cincinnata Mast; redox activity; cell cytotoxicity; α-amylase inhibition; antihyperglycaemic
Online: 17 August 2017 (10:29:55 CEST)
Passiflora cincinnata Mast is a plant popularly used in traditional medicine in northeastern Brazil. The present study aimed to evaluate the anti-lipoperoxidative and anti-α-amylase properties, and cytotoxicity of an extract and fraction of passion fruit leaves (P. cincinnata Mast), as well as the antihyperglecemiant activity of the fraction rich in glycosylated flavonoids and showing low cytotoxicity in rats with a postprandial hyperglycaemia condition. The ethyl acetate fraction (F.ACT) of the P. cincinnata leaves presented the best anti-lipoperoxide properties with TBARs 81.49%, 95.48% and 75.62% lower than AAPH, FeSO4 and H2O2 induced controls, respectively, at 200 μg.mL-1. In addition, it presented an anti-α-amylase potential, with a better ability to inhibit the α-amylase enzyme in comparison to the acarbose control (IC50 6.49 ± 0.11 and 12.01 ± 0.4 μg.mL-1, respectively). The hydroalcoholic extract of P. cincinnata (ExEt) presented high content of total tannins, flavonoids and flavonols. However, F.ACT had the highest concentration of flavonoids among the fractions studied. HPLC analysis of this fraction revealed the presence of the flavonoids isovitexin, orientin and isoorientin. F.ACT showed low to no cytotoxicity below 150 μg.mL-1. Regarding the post-prandial antihyperglycaemic activity of F.ACT, it was observed at 50 and 100 mg.kg-1.
REVIEW | doi:10.20944/preprints202307.0045.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: ERMs; flavonoids; luteolin; mast cells; mediators; moesin; phosphorylation; secretion; SNAREs; SNAPs; tryptase
Online: 3 July 2023 (09:55:52 CEST)
Mast cells play a critical role in allergies and inflammation via secretion of numerous vasoactive, pro-inflammatory and neuro-sensitizing mediators. Secretion may utilize different modes that involve the cytoskeleton, but our understanding of the molecular mechanisms regulating secretion is still not well understood. We previously showed that the ability of the so called mast cell “stabilizer” disodium cromoglycate (cromolyn) to inhibit secretion from rat mast cells closely paralleled the phosphorylation of a 78 kDa protein, and subsequently showed this protein to be moesin, a member of the Ezrin/Radixin/Moesin (ERM) family of proteins, which are involved in linking cell surface-initiated signaling to the actin cytoskeleton. Unlike phosphorylation on the C-terminus Thr558 associated with activation of ERMs, including secretion from macrophages and platelets, we showed that phosphorylation of moesin during inhibition of secretion was on the N-terminal Ser56/74 and Thr66 residues. This phosphorylation pattern could lock moesin in its inactive state and remain inaccessible to bind to the Soluble NSF attachment protein receptors (SNAREs) and synaptosomal associated proteins (SNAPs). Using Confocal microscopic imaging, we showed moesin to colocalize with actin and cluster around secretory granules during inhibition of secretion, In conclusion, the phosphorylation pattern and localization of moesin may be important in the regulation of mast cell secretion and could be targeted for the development of effective inhibitors of secretion from mast cells.
REVIEW | doi:10.20944/preprints202011.0053.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Mast cells; innate immunity; adaptive immunity; wound healing; Immunoglobin E; vaccine adjuvants
Online: 2 November 2020 (14:59:10 CET)
Mast cells are long-lived, granular, myeloid-derived leukocytes that have significant protective and repair functions in tissues. Mast cells sense disruptions in the local microenvironment and are first responders to physical, chemical and biological insults. When activated, mast cells release growth factors, proteases, chemotactic proteins and cytokines thereby mobilizing and amplifying the innate and adaptive immune system. Mast cells are therefore significant regulators of homeostatic functions and may be essential in microenvironmental changes during pathogen invasion and disease. During infection by helminths, bacteria and viruses, mast cells release antimicrobial factors to facilitate pathogen expulsion and eradication. Mast cell-derived proteases and growth factors protect tissues from insect/snake bites and exposure to ultraviolet radiation. Finally, mast cells release mediators that promote wound healing in the inflammatory, proliferative and remodeling stages. Since mast cells have such a powerful repertoire of functions, targeting mast cells may be an effective new strategy for immunotherapy of disease and design of novel vaccine adjuvants. In this review, we will examine how certain strategies that specifically target and activate mast cells can be used to treat and resolve infections, augment vaccines and heal wounds. Although these strategies may be protective in certain circumstances, mast cells activation may be deleterious if not carefully controlled and any therapeutic strategy using mast cell activators must be carefully explored.
ARTICLE | doi:10.20944/preprints201710.0190.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: mast cells; angiogenesis; endothelial cells; tube formation assay; co-culture; gap junction
Online: 31 October 2017 (03:51:50 CET)
Angiogenesis is a complex process that involves interactions between endothelial cells and various other cell types as well as the tissue microenvironment. Several previous studies have demonstrated that mast cells accumulate at angiogenic sites. In spite of the evidence suggesting a relationship between mast cells and angiogenesis, the association of mast cells and endothelial cells remains poorly understood. The present study aims to investigate the relationship between mast cells and endothelial cells during in vitro angiogenesis. When endothelial cells were co-cultured with mast cells, angiogenesis was stimulated. Furthermore, there was direct intercellular communication via gap junctions between the two cell types. In addition, the presence of mast cells stimulated endothelial cells to release angiogenic factors. Moreover, conditioned medium from the co-cultures also stimulated in vitro angiogenesis. The results from this investigation demonstrate that mast cells have both direct and indirect proangiogenic effects and provide new insights into the role of mast cells in angiogenesis.
CASE REPORT | doi:10.20944/preprints202305.0013.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: mast cells; tryptase; carboxypeptidase A3; chymase; fibrogenic niche; kidney fibrosis; specific tissue microenvironment
Online: 1 May 2023 (04:12:22 CEST)
Kidney fibrosis is a complex polyetiological progressive disease manifesting as an intraorgan proliferation of the connective tissue with the appearance of cicatricial changes. However, pathogenetic mechanisms of renal fibrosis remain poorly understood. The paper highlights features of the protease phenotype and histotopography of mast cells (MCs) found in the kidney, as the key players in extracellular matrix remodeling in nephrofibrosis, detected in a patient diagnosed with "nephrosclerosis with the non-functioning upper pole of the duplex right kidney in the junction of refluxing megaureter of the upper pole of the duplex right kidney". The highest content of MCs was found in the kidney areas with fibrotic changes. MCs were actively involved in the development of inflammatory and fibrotic changes in limited loci of the specific tissue microenvironment of the kidney through targeted secretion of tryptase, chymase, and carboxypeptidase A3 to the vascular endothelium, nephron epithelium, interstitium cells, and components of the intercellular substance. The formation of a profibrotic environment in the kidney interstitium was facilitated by epigenetic effects of tryptase promoting epithelial-mesenchymal transition (EMT) of the nephron epithelium. A selectively increased number and targeted secretory activity of MCs in limited loci of the kidney parenchyma without visible pathological changes evidence a trigger pathogenetic role of specific proteases in the formation of a local microenvironment with a profibrogenic metabolic profile. Thus, MCs are actively involved in the mechanisms of formation and evolution of fibrogenic niches in the kidney; this fact can be used to develop new strategies for therapeutic options of tubulointerstitial fibrosis resulted from chronic kidney injury. Further study of the molecular phenotype of mast cells reveals new fundamental mechanisms of fibrosis pathogenesis being a significant tool for personalized therapy in nephrology.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: mast cell; tryptase; chymase; serine protease; human chymase; cleavage specificity; cytokine; chemokine; th2
Online: 26 September 2019 (12:00:55 CEST)
Mast cells (MC) are resident tissue cells found primarily at the interphase between tissues and environment. These evolutionary old cells store large amounts of proteases within cytoplasmic granules, and one of the most abundant of these proteases is the tryptase. To look deeper into the question their in vivo targets, we have analyzed the activity of the human MC tryptase on 69 different human cytokines and chemokines, and the activity of the mouse tryptase (mMCP-6) on 56 mouse cytokines and chemokines. These enzymes were found to be remarkably restrictive in their cleavage of these potential targets. Only five were efficiently cleaved by the human tryptase: TSLP, IL-21, MCP3, MIP-3b and eotaxin. This strict specificity indicates a regulatory function of these proteases and not primarily as unspecific degrading enzymes. We recently showed that the human MC chymase also had a relatively strict specificity, indicating that both of these proteases have regulatory functions. One of the most interesting such regulatory functions may involve controlling excessive TH2 mediated inflammation by cleaving several of the most important TH2-promoting inflammatory cytokines, including IL-18, IL-33, TSLP, IL-15 and IL-21 indicating a potent negative feedback loop on TH2 immunity.
ARTICLE | doi:10.20944/preprints202205.0101.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: mast cell tumor; dog; canine; proliferation indices; grade; prednisone; Ki67; AgNOR; mitotic count; mitotic index
Online: 9 May 2022 (05:22:20 CEST)
Glucocorticoid administration is a common clinical practice in attempt to decrease inflammation associated with, and improve resectability of, canine mast cell tumors (MCTs). However, the impact of neoadjuvant glucocorticoids on histological features and proliferation indices of canine MCTs is unknown. The objective of this study was to evaluate changes in tumor grade, mitotic count, Ki67, AgNOR, and AgNORxKi67 scores following short-course, anti-inflammatory neoadjuvant prednisone in canine patients with MCTs. This was a prospective, single-arm pilot study. Client-owned dogs with treatment-naïve, cytologically-confirmed MCTs were enrolled. Patients underwent an initial incisional biopsy followed by a 10-14 day course of anti-inflammatory prednisone, and surgical resection. All histological samples were randomized, masked, and evaluated by a single pathologist. Unstained paired pre- and post-treatment samples were submitted to a commercial laboratory for Ki67 and AgNOR immunohistochemical analysis. There were 11 dogs enrolled with 11 tumors. There were no statistical differences between the pre- and post-treatment histological parameters of mitotic index, Ki67, AgNOR, or Ki67xAgNOR. There were no clinically-significant alterations between pre-treatment and post-treatment in the assignment of tumor grades. A short-course of anti-inflammatory prednisone does not appear to alter the histological parameters that affect grade-determination, nor significantly alter the proliferation indices in canine MCTs.
REVIEW | doi:10.20944/preprints201702.0095.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: melatonin; testis; androgen production; oxidative stress; inflammation; infertility; Leydig cells; Sertoli cells; mast cells; macrophages
Online: 27 February 2017 (08:56:51 CET)
Environmental darkness signal is transferred from the retina to the pineal gland triggering melatonin secretion. Melatonin influences the synthesis and release of the hypothalamic GnRH and the adenohypophyseal gonadotropin hormones and therefore, regulates testicular function in photoperiodic species. Besides the brain, direct actions of melatonin at the testicular level have also been described. Melatonin released from the pineal gland to the circulation is taken up by peripheral tissues including testes. Testicular synthesis of melatonin has also been reported. The two key somatic cell types in the testis, Leydig and Sertoli cells, express melatonergic receptors. Melatonin acts as a local modulator of the endocrine activity in Leydig cells. In Sertoli cells, melatonin influences the oxidation state and the energy metabolism, and consequently may regulate spermatogenesis. Melatonergic receptors were also described in testicular macrophages and mast cells of infertile patients. Whereas melatonin exerts anti-proliferative and anti-inflammatory effects on testicular macrophages, it provides protective effects against oxidative stress in testicular mast cells. These data pinpoints melatonin as a key player in the regulation of testicular physiology (i.e. steroidogenesis, spermatogenesis) mostly in seasonal breeders. More importantly, melatonin is also involved in the modulation of testicular inflammatory and oxidant/anti-oxidant states in patients with idiopathic infertility.
ARTICLE | doi:10.20944/preprints201807.0317.v3
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Boswellia serrata Roxb.; Curcuma longa L.; intestinal bowel diseases (IBD); Caco-2; PBMC; HMC-1.1; mast cells; cytokines; trans epithelial electrical resistance (TEER); reactive oxygen species (ROS)
Online: 8 November 2018 (04:53:46 CET)
Inflammatory bowel diseases, which consist of chronic inflammatory conditions of the colon and the small intestine, are considered a global disease of our modern society. Recently, the interest toward the use of herbal therapies for the management of inflammatory bowel diseases has increased because of their effectiveness and favorable safety profile, compared to conventional drugs. Boswellia serrata Roxb. and Curcuma longa L. are amongst the most promising herbal drugs, however, their clinical use in inflammatory bowel diseases is limited and little is known on their mechanism of action. The aim of this work was to investigate the effects of two phytochemically characterized extracts of B. serrata and C. longa in an in vitro model of intestinal inflammation. Their impact on cytokine release and reactive oxygen species production, as well as the maintenance of the intestinal barrier function and on intestinal mucosa immune cells infiltration, has been evaluated. The extracts showed a good protective effect on the intestinal epithelium at 1 µg/ml, with TEER values increasing by approximately 1.5 fold, compared to LPS-stimulated cells. C. longa showed an anti-inflammatory mechanism of action, reducing IL-8, TNF-α and IL-6 production by approximately 30%, 25% and 40%, respectively, compared to the inflammatory stimuli. B. serrata action was linked to its antioxidant effect, with ROS production being reduced by 25%, compared to H2O2-stimulated Caco-2 cells. C. longa and B. serrata resulted to be promising agents for the management of inflammatory bowel diseases by modulating in vitro parameters which have been identified in the clinical conditions.