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)

Within seconds after exposure of rat peritoneal mast cells to polymyxin B, bulges appear on the surface of the cells. Freeze-fracture electron microscopy reveals that each bulge overlies a mast cell granule. In contrast to the even distribution of intramembranous particles in the plasma membrane of unstimulated cells, the intramembranous particles in the stimulated cells are unevenly distributed in the membrane of the bulges with large patches of membrane lacking intramembranous particles. The membranes over the most prominent bulges are entirely free of intramembranous particles, and in some instances there is an increased concentration of intramembranous particles at the margins of the bulges. Perigranule membranes exhibit the same changes in distribution of intramembranous particles. Electron microscopy of thin sections of rapidly fixed, stimulated mast cells shows a peculiar structure of the membrane overlying some bulges; instead of the pentalaminar membranes previously demonstrated, the membrane at these sites of presumptive fusion of perigranule and plasma membrane assumes the form of a single dense lamina with a fine fuzzy coating on either side. It seems possible that membrane fusion and subsequent pore formation proceed in the stimulated mast cell through a stage of flight of intramembranous particles and molecular rearrangement of the other membrane components.
 ...
PMID:Freeze-fracture study of mast cell secretion. 18 13

During ultrastructural studies of the early kinetics of anaphylactic degranulation and early and late recovery intervals from these release reactions induced in isolated, partially purified, cultured human lung mast cells stimulated to release histamine and granules by exposure to anti-IgE, we noted the ability of mast cells to undergo morphologic cycles. Following release of most cytoplasmic granules and shedding of large amounts of membranes and cellular processes, small, immature mast cells, nearly devoid of granules, were seen. These lymphocyte-like cells had condensed nuclear chromatin and large nucleoli. Blast transformation of these small cells and expansion of synthetic machinery-laden cytoplasm resulted in large, immature mast cells with small numbers of small, immature progranules and large numbers of lipid bodies in their cytoplasm. This cycle of mast cell morphologic change has considerable similarities to, as well as some differences from, lymphocyte morphologic cycles.
 ...
PMID:Morphologic mast cell cycles. 243 50

We have established an in vitro system with which to examine the ability of Abelson murine leukemia virus (A-MuLV) to infect early hemopoietic progenitor cells. Blast cell colonies containing less than 100 cells were shown to contain up to 85% of cells with secondary hemopoietic colony-forming ability. Infection of cells from these blast colonies resulted in generation of transformed mast cell lines when a feeder was provided. Morphological examination of cells taken from infected cultures at various times postinfection indicated a progression of cellular differentiation to the mast cell lineage. Southern analysis on early subclones of transformed cells from two wells, using a v-abl specific probe, indicated a unique pattern of viral integration amongst subclones, suggesting that all subclones had derived from a single cell in each well. Similar results were observed with helper-free Abelson virus obtained by transfecting psi 2 cells with P160 A-MuLV proviral DNA. These data indicate that hemopoietic progenitor cells can be infected by A-MuLV and subsequently in our in vitro culture condition give rise to transformed mast cell lines.
 ...
PMID:Blast colonies containing hemopoietic progenitor cells can give rise to Abelson virus (A-MuLV)-transformed cell lines. 244

Isolated progenitors of defined type are useful for definitive studies of commitment, growth factor specificity, and identification of viral target cells. Blast cell colonies from cultures of spleen cells obtained from mice treated with 5-fluorouracil have proven to be a useful source of pluripotent progenitors. These colonies also contain committed progenitors of some lineages such as the macrophage lineage; however, the incidence of progenitors for pure erythroid colonies is low in this population. We report here the development of an alternative blast cell colony assay using fetal liver cells that is based on the greater sensitivity of early progenitors to interleukin 3. Replating studies demonstrated a variety of types of secondary colonies, including macrophage, neutrophil, neutrophil/macrophage, megakaryocyte, erythroid, mast cell, and mixed. The incidence of pure erythroid and mast cell colony-forming cells was substantially higher in fetal liver blast cell colonies than in colonies cultured from adult spleen.
 ...
PMID:Fetal liver blast cell colonies: a source of erythroid progenitors. 326 29

The mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF). Cultured mast cells of mi/mi genotype (mi/mi CMCs) did not normally respond to stem cell factor (SCF), a ligand for the c-kit receptor tyrosine kinase. The poor response of mi/mi CMCs to SCF was attributed to the deficient expression of c-kit both the mRNA and protein levels. The purpose of the present study is to investigate the effect of MITF on the transcription of the c-kit gene. First, we introduced cDNA encoding normal (+) MITF or mutant (mi) MITF into mi/mi CMCs using the retroviral vector. Overexpression of (+)-MITF but not mi-MITF normalized the expression of the c-kit and the poor response of mi/mi CMCs to SCF, indicating the involvement of (+)-MITF in the c-kit gene transactivation. Second, we analyzed the promoter of the c-kit gene. Three CANNTG motifs recognized by bHLH-Zip-type transcription factors were conserved between the mouse and human c-kit promoters. Among these three CANNTG motifs, only the CACCTG motif (nt -356 to -351) was specifically bound by (+)-MITF. When the luciferase gene under the control of the c-kit promoter was contransfected into NIH/3T3 fibroblasts with cDNA encoding (+)-MITF or mi-MITF, the luciferase activity significantly increased only when (+)-MITF cDNA was cotransfected. The deletion of the promoter region containing the CACCTG motif or the mutation of the CACCTG to CTCCAG abolished the transactivation effect of (+)-MITF, indicating that (+)-MITF transactivated the c-kit gene through the CACCTG motif. When the luciferase gene under the control of the c-kit promoter was introduced into the FMA3 mastocytoma and FEC-P1 myeloid cell lines, remarkable luciferase activity was observed only in FMA3 cells. Thus, the involvement of (+)-MITF in the c-kit transactivation appeared to be specific to the mast cell lineage.
 ...
PMID:Involvement of transcription factor encoded by the mi locus in the expression of c-kit receptor tyrosine kinase in cultured mast cells of mice. 869 40

Mast cells develop when spleen cells of mice are cultured in the medium containing interleukin (IL)-3. Cultured mast cells (CMCs) show apoptosis when they are incubated in the medium without IL-3. We obtained CMCs from tg/tg mice that did not express the transcription factor encoded by the mi gene (MITF) due to the integration of a transgene at its 5' flanking region. MITF is a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors. We investigated the effect of MITF on the apoptosis of CMCs after removal of IL-3. When cDNA encoding normal MITF ((+)-MITF) was introduced into tg/tg CMCs with the retroviral vector, the apoptosis of tg/tg CMCs was significantly accelerated. The mutant mi allele represents a deletion of an arginine at the basic domain of MITF. The apoptosis of tg/tg CMCs was not accelerated by the introduction of cDNA encoding mi-MITF. The overexpression of (+)-MITF was not prerequisite to the acceleration of the apoptosis, as the apoptotic process proceeded faster in +/+ CMCs than in mi/mi CMCs. The Ba/F3 lymphoid cell line is also dependent on IL-3, and Ba/F3 cells show apoptosis after removal of IL-3. The c-myc gene encodes another transcription factor of the bHLH-Zip family, and the overexpression of the c-myc gene accelerated the apoptosis of Ba/F3 cells. However, the overexpression of (+)-MITF did not accelerate the apoptosis of Ba/F3 cells. The (+)-MITF appeared to play some roles for the acceleration of the apoptosis specifically in the mast cell lineage.
 ...
PMID:Involvement of transcription factor encoded by the mouse mi locus (MITF) in apoptosis of cultured mast cells induced by removal of interleukin-3. 932 38

Mast cells contain a lot of mast cell-specific proteases. We have reported that the expression of mouse mast cell protease 6 (MMCP-6) is remarkably reduced in both cultured mast cells (CMCs) and skin mast cells of mi/mi mutant mice. In the present study, we found that the expression of MMCP-5 was reduced in CMCs but not in skin mast cells of mi/mi mice, and we compared the regulation mechanisms of MMCP-5 with those of MMCP-6. The mi locus encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF). The consensus sequence recognized and bound by bHLH-Zip transcription factors is CANNTG. The overexpression of the normal (+) MITF but not of mi-MITF normalized the poor expression of the MMCP-5 gene in mi/mi CMCs, indicating the involvement of +-MITF in transactivation of the MMCP-5 gene. Although +-MITF directly bound CANNTG motifs in the promoter region of the MMCP-6 gene and transactivated it, the binding of +-MITF to the CAGTTG motif in the promoter region of the MMCP-5 gene was not detectable. The +-MITF appeared to regulate the transactivation of the MMCP-5 gene indirectly. Moreover, addition of stem cell factor to the medium normalized the expression of the MMCP-5 but not of the MMCP-6 gene in mi/mi CMCs. Despite the significant reduction of both MMCP-5 and MMCP-6 expressions in mi/mi CMCs, their regulation mechanisms appeared to be different.
 ...
PMID:Abnormal expression of mouse mast cell protease 5 gene in cultured mast cells derived from mutant mi/mi mice. 937 86

The mi locus encodes a member of the basic - helix - loop - helix - leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF). Although the bHLH-Zip family transcription factors generally recognize and bind CANNTG motifs, the expression of mouse mast cell protease 6 (MMCP-6) gene is regulated by MITF through the GACCTG motif in the promoter region. The GACCTG motif was partly overlapped the TGTGGTC sequence, which was bound by polyomavirus enhancer binding protein 2 (PEBP2). In the present study, the effect of PEBP2 on the expression of MMCP-6 gene was examined. PEBP2 that is composed of alpha and beta subunits was expressed by mast cell lines and cultured mast cells derived from spleen. The overexpression of dominant negative PEBP2 cDNA reduced the expression of MMCP-6. Moreover, the simultaneous transfection of the plasmid containing MITF cDNA and the plasmid containing PEBP2 cDNA increased the MMCP-6 promoter activity. For the synergistic action of PEBP2 and MITF, the intact GACCTG and TGTGGTC motifs were prerequisite. The PEBP2alphaB1 mutant which lacked the region downstream from the Runt domain did not bind MITF and lost the synergistic function. These results indicated that PEBP2 and MITF synergistically transactivated the MMCP-6 gene and that the region downstream from the Runt domain of PEBP2alphaB1 was essential for the physical and functional interactions with MITF.
 ...
PMID:Synergy of PEBP2/CBF with mi transcription factor (MITF) for transactivation of mouse mast cell protease 6 gene. 1046 8

Allergic diseases such as asthma and allergic dermatitis are associated with the degranulation of mast cells. Chymase, a mast-cell-specific protease, is the major component in mast cell granules that can induce eosinophil infiltration into inflammatory sites. We examined the immunopathological mechanisms for the activation of eosinophils by chymase in allergic inflammation. Cytokines were measured by cytometric bead array Flex Sets multiplex assay using flow cytometry and enzyme-linked immunosorbent assay. Adhesion molecules, migration and intracellular signalling pathways were assessed by flow cytometry, Boyden chamber assay and Western blot, respectively. Chymase suppressed the apoptosis of eosinophils and induce the release of the cytokine interleukin-6 (IL-6) and chemokines CXCL8, CCL2 and CXCL1 by eosinophils dose-dependently. It also up-regulated the surface expression of adhesion molecule CD18 and stimulated the chemokinetic migration of eosinophils. The expressions of adhesion molecules, cytokines and chemokines, and chemokinetic migration were differentially regulated by the activation of extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, Akt, Janus-activated kinase and nuclear factor-kappaB pathways. Chymase therefore plays a pivotal immunological role in the interaction between mast cells and eosinophils in allergic diseases such as allergic dermatitis by inducing adhesion molecule-mediated chemokinetic migration and inflammatory cytokines and chemokines of eosinophils, through multiple intracellular signalling molecules and transcription factor. Our results therefore provide a further biochemical basis for the pathogenesis of allergic inflammation consequent on the interaction between mast cells and eosinophils, and give insight for the development of new therapies.
 ...
PMID:Signalling mechanisms regulating the activation of human eosinophils by mast-cell-derived chymase: implications for mast cell-eosinophil interaction in allergic inflammation. 1877 39