Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuropeptides exert a variety of putative immunomodulatory actions. Despite the molecular cloning of multiple forms of receptors for several neuropeptides with putative immunomodulatory effects, including vasoactive intestinal peptide (VIP), the related peptide pituitary adenylate cyclase-activating peptide (PACAP), the opiate peptides, tachykinins, somatostatin and corticotropin-releasing factor, it has not been reported that any of the receptor genes are expressed at significant levels in cells of the immune system. The low level of expression of these receptors and lack of knowledge concerning receptor subtype has impeded progress in understanding how neuropeptides regulate immune function. For example, it is not understood why VIP produces immunomodulatory effects at concentrations far below its receptor-binding affinity. Receptors for VIP and PACAP have recently been cloned. We show here by Northern blot analysis that the VIP/PACAP1 receptor mRNA is present in total RNA prepared from mouse spleen B- and T-lymphocytes. The VIP/PACAP1 receptor mRNA was also present in human peripheral blood lymphocytes, and in a B-lymphocyte and a myelocytic cell line. The mRNA for a second form of the receptor, the VIP/PACAP2 receptor, was not expressed at detectable levels in normal cells, but was detected in several human T-cell lines and a murine mast cell line. The results indicate that VIP/PACAP1 and perhaps VIP/PACAP2 receptors mediate the diverse effects of VIP and PACAP on immune cells.
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PMID:High levels of vasoactive intestinal peptide/pituitary adenylate cyclase-activating peptide receptor mRNA expression in primary and tumor lymphoid cells. 874 41

We determined the effects of immobilization stress on rat colonic mucus release and mast cell degranulation and examined whether corticotropin releasing factor (CRF) was involved in these responses. After 30-min immobilization, rats were killed, colonic mucosal explants were cultured, and levels of rat mast cell protease II (RMCP II) and prostaglandin E2 (PGE2) were measured. Mucin release from explants was assayed by incorporation of [3H]glucosamine into colonic mucin and by histological evaluation of goblet cell depletion. Stress caused significant increases of colonic RMCP II, PGE2, and mucin release and fecal pellet output and caused an approximately 10-fold increase in colonic mucosal levels of cyclooxygenase-2 (COX-2) mRNA. These stress-associated changes were reproduced by intravenous or intracerebral injection of CRF in conscious, nonstressed rats. Pretreatment of rats with the CRF antagonist alpha-helical-CRF9-41, hexamethonium, atropine, or bretylium, or the mast cell stabilizer lodoxamide inhibited stress-induced release of RMCP II, PGE2, and mucin, whereas indomethacin prevented mucin release but not mast cell degranulation. Hexamethonium and CP-96,345, a substance P antagonist, inhibited fecal pellet output caused by stress. We conclude that CRF released during immobilization stress increases colonic transit via a neuronal pathway and stimulates colonic mucin secretion via activation of neurons and mast cells.
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PMID:Acute stress causes mucin release from rat colon: role of corticotropin releasing factor and mast cells. 894 4

Corticotropin-releasing hormone (CRH) is a major regulator of the hypothalamic-pituitary-adrenal axis (HPA) and principal coordinator of the stress response. As in stress, intracerebroventricular administration of CRH suppresses the immune system indirectly, via glucocorticoid and/or sympathetic system-mediated mechanisms. Also, during inflammatory stress, the cytokines TNF alpha, IL-1, and IL-6 stimulate hypothalamic CRH and/or vasopressin secretion as a way of preventing the inflammatory reaction from overreacting. Recently, CRH receptors were described in peripheral sites of the immune system, and CRH was found to promote several immune functions in vitro. We demonstrated a direct role of CRH in the inflammatory immune process in vivo, by first studying the effect of systemic CRH immunoneutralization in an experimental model of carrageenin-induced aseptic inflammation in Spague-Dawley rats. We extended these observations to other forms of experimental inflammation, including streptococcal cell wall polysaccharide- and adjuvant-induced arthritides and peptide R16 (epitope of the interphotoreceptor retinoid-binding protein)-induced uveitis in Lewis rats. We also studied human disease states, including rheumatoid arthritis, Hashimoto thyroiditis, and ulcerative colitis. Inflamed tissues contained large amounts of IR CRH, reaching levels similar to those observed in the hypophyseal portal system. We also demonstrated the presence of CRH mRNA and CRH receptors in inflammatory cells and identified the mast cells as a major immune target for CRH. In addition to production by immune cells, the peripheral nervous system, including the postganglionic sympathetic neurons and the sensory fibers type C, appears to contribute to IR CRH production in inflammatory sites. The production of CRH from the postganglionic sympathetic neurons may be responsible for the stress-induced activation of allergic/autoimmune phenomena, such as asthma and eczema, via mast cell degranulation. Antalarmin, a novel nonpeptide CRH receptor antagonist, displaced 125I-labeled ovine CRH binding in rat pituitary, frontal cortex, and cerebellum, but not heart, consistent with antagonism at the CRHR1 receptor. In vivo antalarmin significantly inhibited CRH-stimulated ACTH release and carrageenin-induced subcutaneous inflammation in rats. Thus, antalarmin and other related compounds that antagonize CRH at the level of its own receptor have therapeutic potential in some forms of inflammation directly mediated by type 1 CRH receptors and promise to enhance our understanding of the many roles of CRH in immune/inflammatory reactions.
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PMID:Corticotropin-releasing hormone and inflammation. 962 33

Previous studies showed that exposure of experimental animals to immobilization stress increases colonic motility and that these effects are mediated by release of corticotropin-releasing factor (CRF), Studies from our laboratory showed that 30-min immobilization stress of rats caused several not previously described colonic responses to stress, including increased colonic mucin and prostaglandin E2 (PGE2) secretion, increased colonic mucosal levels of cyclooxygenase-2 (COX-2) mRNA, and degranulation of colonic mast cells. These stress-associated colonic changes were reproduced by intravenous or intracerebral injection of CRF in conscious, nonstressed rats. Furthermore, pretreatment of rats with the CRF antagonist alpha-helical CRF9-41, hexamethonium, or the mast cell stabilizer lodoxamide inhibited our observed colon responses to immobilization stress. Our results indicate that CRF released during immobilization stress increases colonic transit via a neuronal pathway and stimulates colonic mucin release via activation of neurons and colonic mast cells. These results provide support for an important role for CRF in stress-mediated colonic responses and a link between the nervous and the immune systems.
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PMID:Neuroimmune mechanisms of intestinal responses to stress. Role of corticotropin-releasing factor and neurotensin. 962 90

Recent evidence indicates that glucocorticoids and catecholamines, the end-products of the stress system, and histamine, a product of activated mast cells, might selectively suppress cellular immunity, and favour humoral immune responses. This is mediated by a differential effect of stress hormones and histamine, on T helper 1 (Th1)/Th2 patterns and type 1/type 2-cytokine production. Thus, systemically, stress might induce a Th2 shift, while, locally, under certain conditions, it might induce pro-inflammatory activities through neural activation of the peripheral corticotropin-releasing factor-mast cell-histamine axis. Through the above mechanisms, stress may influence the onset and/or course of infectious, autoimmune/inflammatory, allergic and neoplastic diseases.
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PMID:Stress, cytokine patterns and susceptibility to disease. 1090 16

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis through release of corticotropin releasing factor (CRF), leading to production of glucocorticoids that down regulate immune responses. However, acute stress via CRF also has pro-inflammatory effects. We previously showed that acute stress increases rat blood-brain barrier (BBB) permeability, an effect involving brain mast cells and CRF, as it was absent in W/W(v) mast cell-deficient mice and was blocked by the CRF-receptor antagonist, Antalarmin. We investigated if CRF could also have a direct action on brain microvessel endothelial cells (BMEC) isolated from rat and bovine brain. BMEC were cultured and identified by electron microscopy. Western blot analysis of cultured BMEC identified CRF receptor protein; stimulation with CRF, or it structural analogue urocortin (Ucn) showed that the receptor is functionally coupled to adenylate cyclase as it increased cyclic AMP (cAMP) levels by 2-fold. These findings suggest that CRF could affect BMEC structure or function, as reported for increased cAMP levels by other studies. It is, therefore, possible that CRF may directly regulate BBB permeability, in addition to any effect mediated via brain mast cells.
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PMID:Corticotropin-releasing factor (CRF) can directly affect brain microvessel endothelial cells. 1266 88

Stress results in activation of the hypothalamic pituitary adrenal axis and affects illnesses such as neuroinflammatory syndrome. In vivo acute stress (restraint stress) induces gastrointestinal function disturbances through colonic mast cell activation. This study investigated the effect of acute stress in histamine content of colonic mast cells, and the central role of interleukin-1 (IL-1) and corticotropin-releasing factor (CRF) in this effect. After a restraint stress session colonic segments were isolated and submitted to three protocols: (i) determination of histamine levels by radioimmunoassay (RIA) after incubation with 48/80 compound, (ii) evaluation by histology of mucosal mast cell (MMC) number and (iii) determination of histamine immunoreactivity of MMC. These procedures were conducted (1) in sham or stressed rats, (2) in stressed rats previously treated with intracerebroventricular (I.C.V.) IL-1ra or alpha-helical CRF9-41, (3) in naive rats pretreated with I.C.V. rhIL-1beta or CRF and (4) in rats treated with central IL-1beta and CRF plus alpha-helical CRF and IL-1ra, respectively (cross-antagonism reaction). Acute stress increases histamine content in colonic mast cells, without degranulation. I.C.V. pretreatment with IL-1ra or alpha-helical CRF9-41 blocked stress-induced mast cell histamine content increase. Both I.C.V. rhIL-1beta and CRF injections reproduced the stress-linked changes. I.C.V. treatment with CRF antagonist blocked I.C.V. rhIL-1beta-induced mast cell histamine content increase, whereas central IL-1ra did not affect stress events induced by I.C.V. CRF administration. These results suggest that in rats acute stress increases colonic mast cell histamine content. This effect is mediated by the release in cascade in the brain first of IL-1 and secondly of CRF.
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PMID:Acute stress modulates the histamine content of mast cells in the gastrointestinal tract through interleukin-1 and corticotropin-releasing factor release in rats. 1455 22

Several inflammatory skin conditions, including atopic dermatitis (AD) and psoriasis, are exacerbated by stress. Recent evidence suggests that crosstalk between mast cells, neurons and keratinocytes might be involved in such exacerbation. Mast cells are distributed widely in the skin, are present in increased numbers in AD and are located in close proximity to substance P- or neurotensin-containing neurons. Corticotropin-releasing factor (CRF), its structurally related peptide urocortin (Ucn) and their receptors are also present in the skin and their levels are increased following stress. Human mast cells synthesize and secrete both CRF and Ucn in response to immunoglobulin E receptor (FcepsilonRI) crosslinking. Mast cells also express CRF receptors, activation of which leads to the selective release of cytokines and other pro-inflammatory mediators. Thus, we propose that CRF receptor antagonists could be used together with natural molecules, such as retinol and flavonoids, to inhibit mast cell activation and provide new therapeutic options for chronic inflammatory conditions exacerbated by stress.
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PMID:Mast cells as targets of corticotropin-releasing factor and related peptides. 1549 78

Mast cells are critical for allergic reactions, but also for innate or acquired immunity and inflammatory conditions that worsen by stress. Corticotropin-releasing hormone (CRH), which activates the hypothalamic-pituitary-adrenal axis under stress, also has proinflammatory peripheral effects possibly through mast cells. We investigated the expression of CRH receptors and the effects of CRH in the human leukemic mast cell (HMC-1) line and human umbilical cord blood-derived mast cells. We detected mRNA for CRH-R1alpha, 1beta, 1c, 1e, 1f isoforms, as well as CRH-R1 protein in both cell types. CRH-R2alpha (but not R2beta or R2gamma) mRNA and protein were present only in human cord blood-derived mast cells. CRH increased cAMP and induced secretion of vascular endothelial growth factor (VEGF) without tryptase, histamine, IL-6, IL-8, or TNF-alpha release. The effects were blocked by the CRH-R1 antagonist antalarmin, but not the CRH-R2 antagonist astressin 2B. CRH-stimulated VEGF production was mediated through activation of adenylate cyclase and increased cAMP, as evidenced by the fact that the effect of CRH was mimicked by the direct adenylate cyclase activator forskolin and the cell-permeable cAMP analog 8-bromo-cAMP, whereas it was abolished by the adenylate cyclase inhibitor SQ22536. This is the first evidence that mast cells express functional CRH receptors and that CRH can induce VEGF secretion selectively. CRH-induced mast cell-derived VEGF could, therefore, be involved in chronic inflammatory conditions associated with increased VEGF, such as arthritis or psoriasis, both of which worsen by stress.
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PMID:Human mast cells express corticotropin-releasing hormone (CRH) receptors and CRH leads to selective secretion of vascular endothelial growth factor. 1594 67

Corticotropin-releasing hormone (CRH) is secreted under stress and regulates the hypothalamic-pituitary-adrenal (HPA) axis; it is also secreted outside the brain where it exerts proinflammatory effects, possibly through mast cell activation. Mast cells are necessary for allergic reactions, but are increasingly implicated in acquired immunity and inflammatory diseases worsened by stress. Acute stress and intradermal CRH induced murine skin mast cell activation and increased vascular permeability that was absent in W/W(v) mast cell deficient mice. The presence of functional CRH receptors (CRH-R) was recently reported on human mast cells. Here, we studied the expression of CRH-R1 and CRH-R2 by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent immunocytochemistry in human umbilical cord blood-derived cultured mast cells (hCBMCs) treated with Interleukin (IL)-1, IL-4 or lipopolysaccharide (LPS). Ten week-old hCBMCs cultured in the presence of Stem cell factor (SCF) and IL-6 were positive for both CRH-R1 and CRH-R2. However, the expression of only CRH-R2 mRNA and protein was induced by priming hCBMCs with IL-4 for the last three weeks of culture. Further analysis of the CR-H R2 mRNA expression showed that addition of IL-1 or LPS for 6 h increased only CRH-R2 gene expression. CRH had negligible effect on IL-6 secretion from non-primed hCBMCs, but induced release from IL-4 primed cells. Interestingly, LPS alone increased IL-6 release in non-primed cells, but lost this effect in primed cells. These results further implicate mast cells and CRH in either initiating or potentiating inflammatory diseases, especially those affected by stress.
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PMID:Regulation of corticotropin-releasing hormone receptor-2 expression in human cord blood-derived cultured mast cells. 1632 28


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