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

In studies of the effects of chronic UVB irradiation on dermal connective tissue in the hairless mouse, we observed that the number and size of mast cells was increased. Because mast cells are known to be associated with connective tissue remodeling, we examined and quantified the effect of increasing UVB (290-320 nm) doses on this cell. Groups of mice were exposed to filtered FS-40 Westinghouse lamps (290-400 nm: peak irradiance 313 nm) for 1-5 minimal erythema doses (MED) thrice weekly for 10 weeks. Appropriate controls were included. Biopsies, processed for light microscopy, were stained with toluidine blue. Mast cells were counted in 15 high-magnification fields per specimen with upper and lower dermis scored separately. Significant increases in large densely granular mast cells occurred at 2 MED in the lower dermis, in association with a UVB-exacerbated granulomatous reaction. In the upper dermis, mast cells were significantly increased with 3 MED. These findings suggest that mast cells may play a dual role in UV-irradiated skin with those in the lower dermis related to inflammation processes and those in the upper dermis involved in connective tissue modeling. To gain understanding of the mechanism of mast cell recruitment and maturation, we examined the effect of UVB on mast cell growth factor expression. This was enhanced in the epidermis by UVB, with a shift from cytoplasmic staining to membrane-associated or intercellular staining at 2 MED and higher. Dermal dendritic and mononuclear cells also showed increased reactivity.
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PMID:Ultraviolet B radiation increases hairless mouse mast cells in a dose-dependent manner and alters distribution of UV-induced mast cell growth factor. 857 64

We have quantified perivascular mast cells in cases of urticaria pigmentosa, urticaria, and dermal hypersensitivity reactions. To facilitate reproducibility, the mast cells were counted for a precisely defined vessel unit. These vessel units were divided arbitrarily into those < or = 55 microns and > 55 microns in largest diameters. Urticaria pigmentosa showed an average of 6.4 +/- 1.9 and 22.8 +/- 13.2 mast cells for vessel unit < or = 55 microns and > 55 microns, respectively. Urticaria yielded a lower number of mast cells: 1.5 +/- 0.2 and 2.9 +/- 0.9 for the same respective vessel units. Dermal hypersensitivity reactions revealed an average of 1.6 +/- 0.4 and 2.2 +/- 0.7 mast cells, and the normal skin showed 1.5 +/- 0.3 and 2.4 +/- 0.6 mast cells for each of the vessel units of < or = 55 microns and > 55 microns. The perivascular mast cell distributions of urticaria pigmentosa are statistically different from those of urticaria and dermal hypersensitivity reactions with p < 0.0001. No statistical difference was noted between urticaria, dermal hypersensitivity reactions, and normal skin. The percentages of vessel units < or = 55 microns with > or = 5 mast cells and vessel units > 55 microns with > or = 10 mast cells were determined for each case. The average percentage of vessel units for the former and latter in urticaria pigmentosa was 82.6% and 58.9%, respectively. Urticaria yielded 0% and 0.2%, respectively. None of vessel units in the dermal hypersensitivity reactions or normal skin contained more than 5 mast cells in vessel units < or = 55 microns and more than 10 mast cells in vessel units > 55 microns. Cases of urticaria pigmentosa can be distinguished from other cutaneous eruptions containing mast cells using a simple counting technique on Giemsa stained sections.
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PMID:Perivascular mast cells in urticaria pigmentosa. 879 60

The asebia mouse represents a spontaneous mutation in BALB/c mice leading to hyperplasia of the epidermis and chronic inflammatory dermal changes including enhanced cellularity, oedema and elevated mast cell numbers. We demonstrated that asebia mice have constitutively elevated intercellular adhesion molecule-1 (ICAM-1) mRNA expression, which is not detectable in the wild type, and that dermal mast cell numbers were 3.1-fold higher than the wild type (P < 0.001). We utilized this model to explore the anti-inflammatory effects of cyclosporin A (CsA). After 3 weeks subcutaneous injection with 5 or 10 mg/kg CsA the expression of ICAM-1 mRNA was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and was found to be decreased 2.7-fold (P < 0.001) and three-fold (P < 0.001) relative to controls for 5 and 10 mg/kg treatments, respectively. Dermal mast cell counts were dose-dependently decreased by CsA. Mast cells, visualized by toluidine blue staining, decreased 4.5-fold with 10 mg/kg CsA (P < 0.001) bringing them down to numbers typical of the wild type. CsA also appeared to stabilize mast cell histamine content. Histological examination of haematoxylin-eosin-stained sections revealed that CsA treatment restored the wild-type skin phenotype decreasing epidermal hyperplasia, dermal cellularity and oedema. Thus, CsA exhibits a wide range of anti-inflammatory effects including reduction of ICAM-1 expression and mast cell numbers, and may be useful in the treatment of mast cell-mediated dermatoses.
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PMID:Cyclosporin inhibits intercellular adhesion molecule-1 expression and reduces mast cell numbers in the asebia mouse model of chronic skin inflammation. 915 51

Intercellular adhesion molecule-3 (ICAM-3, CD50), an adhesion receptor of the immunoglobulin superfamily, is suggested to play a key role in adhesive cellular interactions during the initial phase of an immune response. We here provide evidence that ICAM-3 is abundantly expressed by cells of the human mast cell line HMC-1 and, to a lower degree, by purified skin mast cells, as demonstrated by flow-cytometry, ELISA and RT-PCR. ICAM-3 immunoprecipitated from surface biotinylated HMC-1 cells migrates as a broad band of Mr 124,000 by Western blot analysis. We also demonstrate that monoclonal antibodies directed against ICAM-3 are capable of inducing rapid HMC-1 cell aggregation, the extent of which strongly depends on the epitope recognized by the mAb applied. Interestingly, although inhibitable by two of six mAbs against LFA-1, HMC-1 aggregation induced via ICAM-3 appears to be mediated by an adhesive pathway independent of LFA-1. Dermal mast cells are also aggregated with anti-ICAM-3 mAbs, a phenomenon which has not been described before for isolated tissue mast cells. However, this process displays slower kinetics, as compared to HMC-1 cells. That anti-ICAM-3 mAbs are able to mediate biological effects is further illustrated by their capability to increase stimulation-dependent release of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-8 from HMC-1 cells. Taken together, these results indicate that ICAM-3 is not only expressed by immature and mature human mast cells, but also possesses functional relevance and may therefore play a significant role in mast cell associated processes.
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PMID:ICAM-3 (CD50) is expressed by human mast cells: induction of homotypic mast cell aggregation via ICAM-3. 1062 4

Ultraviolet B radiation is immunosuppressive by multiple mechanisms. In interleukin-4-/- mice, ultraviolet B radiation was not able to suppress delayed-type hypersensitivity or contact hypersensitivity responses when the sensitizing antigen was applied to nonirradiated sites. In contrast, ultraviolet B significantly suppressed contact hypersensitivity responses to haptens applied to irradiated sites in interleukin-4-/- mice. In mast cell depleted Wf/Wf mice, ultraviolet B radiation also significantly suppressed contact hypersensitivity responses to sensitizing antigens applied to irradiated but not to unirradiated sites. In both interleukin-4-/- mice and Wf/Wf mice, the mast cell product, histamine, was immunosuppressive implicating mast cells as the dysfunctional cell in interleukin-4-/- mice. The prevalence of dermal mast cells was similar in wild-type and interleukin-4-/- mice. Dermal mast cells of interleukin-4-/- mice, however, express very low levels of c-kit and did not significantly degranulate in response to ultraviolet B. Ultraviolet radiation induced significant and similar levels of serum interleukin-10 in wild-type and interleukin-4-/- mice. We conclude that interleukin-4 indirectly affects ultraviolet B suppression of contact hypersensitivity and delayed-type hypersensitivity responses to sensitizing antigens applied at sites other than those irradiated by providing a critical differentiative signal for dermal mast cells. This study further emphasizes the central role of mast cells in the initial processes by which ultraviolet B radiation is immunomodulatory for immune responses to sensitizing antigens applied to nonirradiated sites.
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PMID:Ultraviolet B-induced suppression of immune responses in interleukin-4-/- mice: relationship to dermal mast cells. 1069 10

Although the etiology of urticaria is mostly unclear, there are a number of recent new insights into the underlying pathomechanisms and causes. Dermal mast cell numbers and endothelial cell adhesion molecule and cytokine expression are also increased in uninvolved skin, while serum P-selectin levels are elevated, suggesting a systemic activation of the cutaneous inflammatory system in urticaria. In all adults, but not children with indolent mastocytosis, we found activating point mutations of c-kit, the mast cell growth factor receptor, in lesional cutaneous mast cells. In acute urticaria, IgE-dependent mechanisms are only rarely involved (0.9%), in contrast to generally held beliefs, whereas acute upper respiratory infections (39.3%) and drug intolerance (9.2%) are more frequent. In chronic urticaria, pseudoallergies to food (73%) and more rarely chronic inflammatory gastrointestinal diseases (11%) play a major role, with avoidance or elimination of the eliciting factors leading to long term remission. On the basis of recent findings, autoantibodies must be viewed mostly as secondary rather than causative in chronic urticaria.
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PMID:[Urticaria. New developments and perspectives]. 1087 66

Dermal dendrocytes (DDs) are bone marrow-derived cells which are abundant in normal human and murine dermis, where they are closely associated with mast cells in the perivascular space. The biological role of DDs remains enigmatic. DDs express coagulation factor XIIIa and the recently described von Willebrand factor receptor, GPIb alpha, potentially indicating a function in tissue repair and haemostasis, although participation in antigen presentation is also speculated. In healing wounds and 'fibrohistiocytic' tumours, such as dermatofibromas, DDs are often associated with non-dendritic histiocytes, some of which also express factor XIIIa (FXIIIa). We have utilized human skin organ culture to examine the effects of various biological mediators on cytological characteristics of DDs. It was found that by 24 h in organ culture, immunoreactive DDs begin to lose their dendritic shape, assuming more rounded contours. This phenomenon was accentuated by mast cell degranulation; was independent of the nature of mast cell secretagogue; and could not be reproduced by recombinant tumour necrosis factor-alpha, a cytokine known to increase FXIIIa expression in DDs. Like their dendritic precursors, non-dendritic cells expressed variable FXIIIa, CD34 and CD68 and did not express CD1a or CD45. By ultrastructure, non-dendritic cells that develop in vitro resembled non-degenerating monocytes containing occasional primary lysosomes and lipid inclusions, and like DDs, expressed fibronexus-like plaques on the cell membrane. Transition of DDs from dendritic to non-dendritic cells as a consequence of specific microenvironmental influences may provide insight into the frequent concurrence of these two cytological types in fibrohistiocytic tissue reactions and neoplasia.
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PMID:Cytological alterations in dermal dendrocytes in vitro: evidence for transformation to a non-dendritic phenotype. 1088 40

The deleterious effects of ultraviolet B radiation (UVR) on cutaneous immunity are mediated in part by cytokines released from cutaneous cells following radiation exposure. On the one hand, TNF-alpha has been advocated as the primary mediator of failed contact hypersensitivity induction, and, on the other hand, IL-10 has been held responsible for tolerance. While keratinocytes exposed to UVR have been found to produce both TNF-alpha and IL-10, there is reason to question whether these major cellular constituents of the epidermis are the relevant source of immunomodulatory cytokines after UVR. Dermal mast cells also produce TNF-alpha and IL-10, and we have recently reported that mast cell-derived TNF-alpha is required for UVR-induced impairment of CH induction. In this study, we have examined whether mast cells are also a relevant source of IL-10 in UVR-dependent tolerance. We found that (a) UVR fails to induce tolerance in mast cell-deficient mice, and (b) that tolerance occurs if mast cells are triggered to degranulate after ligation of the IgE receptor. Both types of tolerance were neutralized with anti-IL-10 antibodies, are hapten specific, and are associated with regulatory lymphoid cells. We conclude that mast cells are required in UVR-induced tolerance and may be one of the major sources of IL-10 that mediates the tolerance induced by acute, low-dose UVR.
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PMID:Hapten-specific tolerance induced by acute, low-dose ultraviolet B radiation of skin requires mast cell degranulation. 1138 18

The effect of dermal application of halofuginone-an inhibitor of collagen type I synthesis-on skin collagen and collagen alpha1(I) gene expression in an animal model of scleroderma and chronic graft versus host disease (cGvHD) was evaluated. Halofuginone-containing cream was applied on the tight-skin mouse (Tsk) and skin biopsies were taken for collagen staining by sirius red and for collagen alpha1(I) gene expression by in situ hybridization. In addition, cell proliferation was evaluated by immunostaining for proliferation cell nuclear antigen (PCNA) alone or in combination with collagen alpha1(I) probe. The number of mast cells was assessed by toluidine blue. Dermal application of halofuginone (0.01%) for 60 days was as good as systemic administration (1 microg/mouse/day) in reducing collagen alpha1(I) gene expression in skin biopsy and almost as good in reducing skin width. Halofuginone was stable and effective only at acidic pH. The effect of halofuginone (0.03%) was time-dependent. After 40 days of daily treatment, a significant reduction in the collagen alpha1(I) gene expression was observed and further decrease was observed after 60 days. The reduction in collagen alpha1(I) gene expression and the reduction in the proliferation of dermal fibroblasts probably occur in the same subset of cells. No effect of halofuginone on the proliferation of keratinocytes or on mast cell number was observed. These results suggest that target-oriented application of halofuginone may become a novel therapy for fibrotic disorders in general and for scleroderma in particular.
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PMID:Reduction in dermal fibrosis in the tight-skin (Tsk) mouse after local application of halofuginone. 1170 55

To investigate the role of mast cells in treatment-associated adverse reactions in patients with onchocerciasis, changes in plasma tryptase levels and skin mast cell counts were examined in 2 groups of Onchocerca volvulus-infected subjects after ivermectin treatment. After treatment, an increase in tryptase levels was observed concurrent with the onset of blood eosinopenia and preceding the appearance of plasma eosinophil-derived neurotoxin (EDN) and interleukin-5. Tryptase levels were correlated with development of peripheral eosinopenia and markers of eosinophil activation and degranulation. Dermal mast cell numbers increased transiently at 24 h after treatment, preceding the onset of dermal eosinophil infiltration and the development of clinically apparent inflammation. Local reactions were strongly correlated with levels of plasma tryptase and EDN, and the severity of systemic reactions was correlated with levels of tryptase, EDN, and interleukin-5. The data indicate that mast cells play a role in initiation of tissue inflammatory reactions after ivermectin treatment of onchocerciasis.
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PMID:Association of transient dermal mastocytosis and elevated plasma tryptase levels with development of adverse reactions after treatment of onchocerciasis with ivermectin. 1240


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