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)

Mast cells are critical players in allergic reactions, but they have also been shown to be important in immunity and recently also in inflammatory diseases, especially asthma. Migraines are episodic, typically unilateral, throbbing headaches that occur more frequently in patients with allergy and asthma implying involvement of meningeal and/or brain mast cells. These mast cells are located perivascularly, in close association with neurons especially in the dura, where they can be activated following trigeminal nerve, as well as cervical or sphenopalatine ganglion stimulation. Neuropeptides such as calcitonin gene-related peptide (CGRP), hemokinin A, neurotensin (NT), pituitary adenylate cyclase activating peptide (PACAP), and substance P (SP) activate mast cells leading to secretion of vasoactive, pro-inflammatory, and neurosensitizing mediators, thereby contributing to migraine pathogenesis. Brain mast cells can also secrete pro-inflammatory and vasodilatory molecules such as interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF), selectively in response to corticotropin-releasing hormone (CRH), a mediator of stress which is known to precipitate or exacerbate migraines. A better understanding of brain mast cell activation in migraines would be useful and could lead to several points of prophylactic intervention.
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PMID:The role of mast cells in migraine pathophysiology. 1596 Sep 87

Mast cells accumulate in tissues undergoing angiogenesis during tumor growth, wound healing, and tissue repair. Mast cells can secrete angiogenic factors such as vascular endothelial growth factor (VEGF). Ionizing irradiation has also been shown to have angiogenic potential in malignant and nonmalignant diseases. We observed that low-dose irradiation fosters mast cell-dependent vascular regeneration in a limb ischemia model. Irradiation promoted VEGF production by mast cells in a matrix metalloproteinase-9 (MMP-9)-dependent manner. Irradiation, through MMP-9 up-regulated by VEGF in stromal and endothelial cells, induced the release of Kit-ligand (KitL). Irradiation-induced VEGF promoted migration of mast cells from the bone marrow to the ischemic site. Irradiation-mediated release of KitL and VEGF was impaired in MMP-9-deficient mice, resulting in a reduced number of tissue mast cells and delayed vessel formation in the ischemic limb. Irradiation-induced vasculogenesis was abrogated in mice deficient in mast cells (steel mutant, Sl/Sl(d) mice) and in mice in which the VEGF pathway was blocked. Irradiation did not induce progenitor mobilization in Sl/Sl(d) mice. We conclude that increased recruitment and activation of mast cells following irradiation alters the ischemic microenvironment and promotes vascular regeneration in an ischemia model. These data show a novel mechanism of neovascularization and suggest that low-dose irradiation may be used for therapeutic angiogenesis to augment vasculogenesis in ischemic tissues.
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PMID:Low-dose irradiation promotes tissue revascularization through VEGF release from mast cells and MMP-9-mediated progenitor cell mobilization. 1615 86

This paper reviews the role of mast cells in the development and progression of basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Mast cells accumulate around cutaneous malignancies. Current evidence suggests that mast cells contribute to the tumorigenesis of cutaneous malignancies through four mechanisms. (1) Immunosuppression: Ultraviolet-B radiation, the most important initiator of cutaneous malignancies, activates mast cells. Upon irradiation of the skin, trans-urocanic acid in the epidermis isomerizes to cis-urocanic acid, which stimulates neuropeptide release from neural c-fibers. These neuropeptides in turn trigger histamine secretion from mast cells, leading to suppression of the cellular immune system. (2) Angiogenesis: Mast cells are the major source of vascular endothelial growth factor in basal cell carcinoma and malignant melanoma. Vascular endothelial growth factor is one of the most potent angiogenic factors, which also induces leakage of other angiogenic factors across the endothelial cell wall into the matrix. Mast cell proteases reorganize the stroma to facilitate endothelial cell migration. As well, heparin, the dominant mast cell proteoglycan, assists in blood-borne metastasis. (3) Degradation of extracellular matrix: Through its own proteases, and indirectly via interaction with other cells, mast cells participate in degradation of the matrix, which is required for tumor spread. (4) Mitogenesis: Mast cell mediators including fibroblast growth factor-2 and interleukin-8 are mitogenic to melanoma cells. Current evidence supports an accessory role for mast cells in the development and progression of cutaneous malignancies. Emerging data, however, also suggest that mast cells might, in fact, have opposing roles in tumor biology, and the microenvironment could polarize mast cells to possess either promoting or inhibitory effects on tumors.
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PMID:Mast cells and cutaneous malignancies. 1625 17

We have previously demonstrated that adrenomedullin (AM) plays a critical role as an autocrine/paracrine tumor cell survival factor. We now present evidence that AM is an important regulator of mast cell (MC) function and that this modulation is potentially involved in tumor promotion. AM induced histamine or beta-hexosaminidase release from rat and human MCs through a receptor-independent pathway. AM was chemotactic for human MCs and stimulated mRNA expression of vascular endothelial growth factor, monocyte chemoattractant protein-1, and basic fibroblast growth factor in this cell type. Differentiated but not undifferentiated human MCs responded to hypoxic insult with elevated AM mRNA/protein expression. Using confocal microscopy, we identified AM-producing MCs in tumor infiltrates of human breast and lung cancer patients. In mixed culture assays the AM-producing human MC line HMC-1 augmented both anchorage-dependent and -independent growth of human lung cancer A549 cells, an effect that was suppressed by MC-targeted siRNA AM knockdown. Finally, HMC-1 cells induced in vivo angiogenesis as assessed by directed in vivo angiogenesis assay analysis; neutralizing anti-AM monoclonal antibody blocked this ability. Our collective data suggest a new role for AM as a cross-talk molecule that integrates tumor and MC communication, underlying a unique promotion mechanism of human cancers.
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PMID:Adrenomedullin is a cross-talk molecule that regulates tumor and mast cell function during human carcinogenesis. 1640 30

Increased blood-brain-barrier (BBB) permeability precedes any clinical or pathologic signs and is critical in the pathogenesis of multiple sclerosis (MS) and brain metastases. CD4+ TH1 cells mediate demyelination in MS, but how they get sensitized and enter the brain to induce brain inflammation remains obscure. TH2 cytokines associated with allergic disorders have recently been implicated in MS, while genes upregulated in MS plaques include the mast cell-specific tryptase, the IgE receptor (Fc-epsilon-RI) and the histamine-1 receptor. Mast cell specific tryptase is elevated in the CSF of MS patients, induces microvascular leakage and stimulates protease-activated receptors (PAR), leading to widespread inflammation. BBB permeability, MS and brain metastases appear to worsen in response to acute stress that leads to the local release of corticotropin-releasing hormone (CRH), which activates brain mast cells to selectively release IL-6, IL-8 and vascular endothelial growth factor (VEGF). Acute stress increases BBB permeability that is dependent on CRH and mast cells. Acute stress shortens the time of onset of experimental alleric encephalomyelitis (EAE) that does not develop in W/W mast cell deficient or CRH -/- mice. Brain mast cell inhibition and CRHR antagonists offer novel therapeutic possibilities.
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PMID:Corticotropin-releasing hormone and the blood-brain-barrier. 1712 8

Mast cells are well known for their involvement in allergic and anaphylactic reactions, during which immunoglobulin E (IgE) receptor (Fc epsilon RI) aggregation leads to exocytosis of the content of secretory granules (1000 nm), commonly known as degranulation, and secretion of multiple mediators. Recent findings implicate mast cells also in inflammatory diseases, such as multiple sclerosis, where mast cells appear to be intact by light microscopy. Mast cells can be activated by bacterial or viral antigens, cytokines, growth factors, and hormones, leading to differential release of distinct mediators without degranulation. This process appears to involve de novo synthesis of mediators, such as interleukin-6 and vascular endothelial growth factor, with release through secretory vesicles (50 nm), similar to those in synaptic transmission. Moreover, the signal transduction steps necessary for this process appear to be largely distinct from those known in Fc epsilon RI-dependent degranulation. How these differential mast cell responses are controlled is still unresolved. No clinically available pharmacological agents can inhibit either degranulation or mast cell mediator release. Understanding this process could help develop mast cell inhibitors of selective mediator release with novel therapeutic applications.
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PMID:Differential release of mast cell mediators and the pathogenesis of inflammation. 1749 52

Vascular growth of the uterine cervix during pregnancy is associated with mast cell (MC) degranulation. To better understand the mechanism underlying this process, uterine cervices of intact pregnant rats were dissected and endothelial cell proliferation was measured by a bromodeoxyuridine incorporation technique. Total vascular endothelial growth factor (VEGF) mRNA expression and the relative abundance of VEGF splice variants (120, 164, and 188) were determined by RT-PCR. VEGF protein expression was evaluated by immunohistochemistry. To investigate the role of MCs on cervical angiogenesis, a second set of pregnant animals were treated with an MC stabilizer (disodium cromoglycate) to inhibit MC degranulation. Furthermore, 17beta-estradiol (E(2)) serum levels were established by RIA. In intact pregnant rats, VEGF mRNA expression was positively correlated with endothelial cell proliferation and circulating E(2) levels. All selected splice variants of VEGF gene were detected and their relative abundance did not show any change throughout pregnancy. Animals treated with disodium cromoglycate showed a decrease in endothelial cell proliferation and in VEGF mRNA expression compared with controls. Relative abundance of VEGF mRNA splice variants and E(2) serum levels showed no differences between these experimental groups. These results show a time-dependent correlation between VEGF mRNA expression and E(2) serum levels in the uterine cervix of intact pregnant rats, while MC stabilizer-treated animals reduced the VEGF expression without modifying E(2) serum levels. We suggest that cervical angiogenesis during pregnancy could be regulated by a mechanism which involves endogenous E(2) and chemical mediators stored in MC granules via a VEGF-dependent pathway.
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PMID:Mast cell degranulation in rat uterine cervix during pregnancy correlates with expression of vascular endothelial growth factor mRNA and angiogenesis. 1761 33

The citrus unshiu peel has been used traditionally as a medicine to improve bronchial and asthmatic conditions or cardiac and blood circulation in Korea, China, and Japan. Here, we report the effects of citrus unshiu peel water extract (CPWE) on the phorbol myristate acetate (PMA)+calcium ionophore A23187-induced hypoxia-inducible factor-1alpha (HIF-1alpha) activation and inflammatory cytokine production from the human mast cell line, HMC-1 cells. We compared CPWE with hesperidin, a common constituent of citrus unshiu. CPWE and hesperidin inhibited the PMA+A23187-induced HIF-1alpha expression and the subsequent production of vascular endothelial growth factor (VEGF). In addition, CPWE suppressed PMA+A23187-induced phosphorylation of the extracellular signal-regulated kinase (ERK). We also show that the increased cytokines interleukin (IL)-1beta, IL-8, and tumor necrosis factor (TNF)-alpha level was significantly inhibited by treatment of CPWE or hesperidin. In the present study, we report that CPWE and hesperidin are inhibitors of HIF-1alpha and cytokines on the mast cell-mediated inflammatory responses.
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PMID:Hesperidin inhibits expression of hypoxia inducible factor-1 alpha and inflammatory cytokine production from mast cells. 1762 75

Mast cells are effector cells of IgE-mediated immune responses frequently found at the vicinity of blood vessels, the margins of diverse tumors and at sites of potential infection and inflammation. Upon IgE-mediated stimulation, mast cells produce and secrete a broad spectrum of cytokines and other inflammatory mediators. Recent work identified JunB, a member of the AP-1 transcription factor family, as critical regulator of basal and induced expression of inflammatory mediators in fibroblasts and T cells. To study the impact of JunB on mast cell biology, we analyzed JunB-deficient mast cells. Mast cells lacking JunB display a normal in vivo maturation, and JunB-deficient bone marrow cells in vitro differentiated to mast cells show no alterations in proliferation or apoptosis. But these cells exhibit impaired IgE-mediated degranulation most likely due to diminished expression of SWAP-70, Synaptotagmin-1, and VAMP-8, and due to impaired influx of extracellular calcium. Moreover, JunB-deficient bone marrow mast cells display an altered cytokine expression profile in response to IgE stimulation. In line with these findings, the contribution of JunB-deficient mast cells to angiogenesis, as analyzed in an in vitro tube formation assay on matrigel, is severely impaired due to limiting amounts of synthesized and secreted vascular endothelial growth factor. Thus, JunB is a critical regulator of intrinsic mast cell functions including cross-talk with endothelial cells.
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PMID:JunB is required for IgE-mediated degranulation and cytokine release of mast cells. 1798 78

Endostatin, a proteolytic fragment of collagen XVIII, is a potent inhibitor of angiogenesis and tumor growth. We studied the development of carcinogen-induced skin tumors in transgenic J4 mice overexpressing endostatin in their keratinocytes. Unexpectedly, we did not observe any differences in tumor incidence and multiplicity between these and control mice, nor in the rate of conversion of benign papillomas to malignant squamous cell carcinomas (SCC). We did find, however, that endostatin regulates the terminal differentiation of keratinocytes because the SCCs in the J4 mice were less aggressive and more often well differentiated than those in the control mice. We observed an inhibition of tumor angiogenesis by endostatin at an early stage in skin tumor development, but more strikingly, there was a significant reduction in lymphatic vessels in the papillomas and SCCs in association with elevated endostatin levels and also a significant inhibition of lymph node metastasis in the J4 mice. We showed that tumor-infiltrating mast cells strongly expressed vascular endothelial growth factor-C (VEGF-C), and that the accumulation of these cells was markedly decreased in the tumors of the J4 mice. Moreover, endostatin inhibited the adhesion and migration of murine MC/9 mast cells on fibronectin in vitro. Our data suggest that endostatin can inhibit tumor lymphangiogenesis by decreasing the VEGF-C levels in the tumors, apparently via inhibition of mast cell migration and adhesion, and support the view that the biological effects of endostatin are not restricted to endothelial cells because endostatin also regulates tumor-associated inflammation and differentiation, and the phenotype of epithelial tumors.
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PMID:Endostatin overexpression inhibits lymphangiogenesis and lymph node metastasis in mice. 1808 81


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