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)

Although mediator release from mast cells and basophils plays a central role in the pathogenesis of human allergic disease, biochemical studies have been restricted to rat peritoneal mast cells and basophilic leukemia cells because they could be easily purified. We have used two new techniques of cell separation to purify human lung mast cells to 98% homogeneity. Lung cell suspensions were obtained by dispersion of chopped lung tissue with proteolytic enzymes. Mast cells were then purified from the suspensions by countercurrent centrifugal elutriation and affinity chromatography. The purified mast cells released both histamine and slow-reacting substance of anaphylaxis (SRS-A) (leukotriene C and D) during stimulation with goat anti-human IgE antibody. Moreover, these preparations were able to generate significant quantities of SRS-A (32 +/- 7 x 10(-17) LTD mole-equivalents/mast cell) at all stages of purification, indicating that a secondary cell is not necessary for the antigen-induced release of SRS.
 ...
PMID:Generation of leukotrienes by purified human lung mast cells. 711 13

The syndrome of mastocytosis extends from cutaneous urticaria pigmentosa through systemic mastocytosis to the rarely occurring mast cell leukaemia. Our investigations with a large patient collective have shown that systemic forms of the disease occur more often than is generally supposed. In particular the incidence of bone marrow manifestations deserve more attention. The inflammatory-granulomatous findings in the bone marrow suggest an immunoactive component in the pathogenesis of this disease. The bone lesions that occur in about 50% of patients are probably the result of the common endosteal site of the mastocytosis granuloma. These lesions can be generalized (osteoporosis-osteosclerosis) or localized (osteolytic-osteosclerotic foci). In clinical practice bone biopsy and skeletal radiology complement one another; in addition to skin biopsy bone biopsy supplies the initial diagnosis of mastocytosis and documents systemic manifestation; the X-ray picture informs the clinician about the type and extent of the bone pathology.
 ...
PMID:[Skin and bone findings in mastocytosis]. 715 88

The authors describe the results of a series of cytochemical, autoradiographic, cytophotometric and immunological investigations carried out in a case of tissue mast cell leukaemia. Leukaemic mast cells showed certain distinctive cytochemical features, amongst which an intense periodic acid-Schiff (PAS) reaction, sensitive to amylase digestion, strong naphthol AS-D chloroacetate esterase (NASDCE), intense lactate dehydrogenase (LD) activity. Proliferative activity, determined autoradiographically with 3H-dT, was considerably low and was mainly confined to the larger cells. Also uridine and leucine incorporation were markedly reduced. Microdensitometry disclosed that the mast cell population was mainly arrested in the G1 phase. Because of previous attempts to destroy selectively neoplastic tissue mast cells with sheep antihuman IgE serum, a search for surface bound IgE was carried out, but gave a negative result. Possible therapeutic approaches are considered in the light of previous clinical experience and on the basis of the results of the kinetic and metabolic studies.
 ...
PMID:Cytobiological and clinical aspects of tissue mast cell leukaemia. 737 28

It has been shown that the major cyclooxygenase product in rat basophilic leukemia (RBL-1) cells and in normal rat mast cells is prostaglandin D2. In RBL-1 cells, prostaglandin D2 is isomerase activity was found in the 150 000 X g microsomal pellet as well as the supernatant fraction. Incubation of RBL-1 microsomes with arachidonic acid without cofactors yielded 17.5 +/- 2% prostaglandin E2 and 9.1 +/- 1.4% prostaglandin D2. The cyclooxygenase activity was enhanced (25%) by epinephrine and the addition of reduced glutathione led to a marked increase in prostaglandin D2 synthesis (3-fold). Incubations with arachidonic acid, glutathione and epinephrine gave the maximum conversion to prostaglandin D2, yielding 7 +/- 0.4% prostaglandin E2 and 35.6 +/- 3.5% prostaglandin D2. Incubations with [14C]prostaglandin H2 to bypass cyclooxygenase confirmed the presence and glutathione dependence of the prostaglandin D2 isomerase in the microsomal fraction and also revealed the presence of the same enzyme in the 150 000 X g supernant. In contrast to RBL-1 cells, incubations of microsomes and supernatant from normal rat mast cells with [14C]-arachidonic acid and [14C]prostaglandin H2 localized the prostaglandin D2 isomerase activity in the soluble fraction. Similar to the enzyme in the RBL-1 cells, the mast cell enzyme was glutathione dependent.
 ...
PMID:Enzymatic formation of prostaglandin D2 by rat basophilic leukemia cells and normal rat mast cells. 737 31

The expression of the c-kit gene product has been examined in normal mast cells, mast cell neoplasms, and basophil/mast cell precursors obtained from patients with chronic myelogenous leukaemia (CML). Formalin-fixed, paraffin-embedded sections or smears fixed with formalin vapour were studied by immunohistochemical methods, using a polyclonal antibody against the c-kit gene product. Normal and neoplastic mast cells showed a positive immunoreaction for c-kit gene product, but neoplastic basophil/mast cell precursors from CML patients lacked c-kit gene product by immunohistochemical and flow cytometric methods, even in cells having mast cell granules, together with or without basophil granules. Mast cell tryptase was, however, expressed in normal and neoplastic mast cells and basophil/mast cell precursors containing mast cell granules. In addition, cells of monocyte/macrophage lineage lacked c-kit gene product. These findings indicate that the c-kit gene product may play an important role in the development and function of mast cell but not of cell of basophil and monocyte/macrophage lineage.
 ...
PMID:Expression of the c-kit gene product in normal and neoplastic mast cells but not in neoplastic basophil/mast cell precursors from chronic myelogenous leukaemia. 749 Jun 80

Rat basophilic leukemia (RBL) cells are considered to be similar to bone-marrow derived mast cells and to mucosal mast cells (MMC), the latter of which may be involved in inflammatory bowel diseases. RBL cells are not able to accumulate histamine and secretory granules under regular growing conditions. Here we show that the flavonoid quercetin, which inhibits mast cell secretion of histamine, also inhibited RBL cell proliferation and constitutive histamine release while it induced synthesis of rat mast cell protease (RMCP) II and triggered processes leading to accumulation of secretory granules. Cell viability was also retained in the presence of quercetin, whereas untreated cells did not survive past 6 days of growth. Quercetin did not affect the expression of mRNA for alpha-subunit of immunoglobulin E (IgE) receptor, but led to increased expression of mRNA for, and synthesis of RMCP II, which is a marker protein for MMC. Many of these granules showed metachromasia with toluidine blue after 3 days of growth, stained red with alcian blue counterstained with safranin after 8 days of growth, and contained electron dense material. Our results suggest that RBL cells have the capacity to progress to a more mature state and may lend themselves to further analysis of a growth regulator(s) with action similar to that of quercetin.
 ...
PMID:Quercetin-induced expression of rat mast cell protease II and accumulation of secretory granules in rat basophilic leukemia cells. 750 28

The c-kit proto-oncogene encodes a receptor tyrosine kinase that is known to play a crucial role in mast cell growth and differentiation. In a human mast cell leukemia cell line (HMC-1), KitR was found to be constitutively phosphorylated on tyrosine, activated and associated with phosphatidylinositol 3-kinase (P13K) in the absence of autocrine production of SCF. Sequencing of c-kit cDNA revealed that c-kit genes of HMC-1 cells were composed of a normal, wild-type allele and a mutant allele with two point mutations in codon 560 and codon 816, resulting in intracellular amino acid substitutions of Gly-560 for Val and Val-816 for Asp, respectively. Murine c-kit mutants encoding Gly-559 and/or Val-814, corresponding to human Gly-560 and/or Val-816, were constructed by site-directed mutagenesis and expressed in cells of a human embryonic kidney cell line (293T). In the transfected cells, KitR (Gly-559 + Val-814) and KitR (Val-814) were strikingly phosphorylated on tyrosine and activated in the absence of SCF, whereas tyrosine phosphorylation and activation of KitR (Gly-559) or wild-type KitR was modest or little, respectively. These results suggest that constitutive activation of KitR in HMC-1 results from the activating mutations of c-kit gene, and raise the possibility that the activating mutations, particularly at codon 814 of murine c-kit or at codon 816 of human c-kit, may participate in oncogenesis of mast cells.
Leukemia 1994 Apr
PMID:Activating mutations of the c-kit proto-oncogene in a human mast cell leukemia cell line. 751 80

The c-kit receptor is a tyrosine-kinase transmembrane receptor first identified as an oncogene in the HZ4-feline leukemia virus and later found to be important in hematopoiesis in mice. The ligand for this receptor (Steel factor) can stimulate hematopoiesis both in vitro and in vivo. To study the pattern of c-kit receptor expression in normal human hematopoietic progenitor cells, we prepared a monoclonal antibody (9B9) against human c-kit receptor by using a synthetic peptide (amino acids 476-501) from the extracellular domain of c-kit receptor to immunize Balb/c mice. Monoclonal antibody 9B9 bound to recombinant c-kit protein, the erythroleukemic line HEL, the megakaryocytic line MEG-01, and the murine mast cell line P815. Monoclonal antibody 9B9 also bound to the surface of the CD7+CD3-CD4-CD8- T cell lymphoid cell lines DU.528 and HSB2T, and also to 1 to 4% of normal bone-marrow cells. The majority (67 +/- 6%) of CD34+ bone-marrow progenitor cells coexpressed c-kit receptor. Flow-cytometry analysis of immature CD3-CD4-CD8- (triple-negative) thymocytes indicated 30 +/- 9.5% expressed the c-kit receptor, and thymidine incorporation assay revealed that the receptor is functional. Indirect fluorescent microscopy of human thymic tissue, using a monoclonal antibody against Steel factor, revealed its presence on scattered mononuclear cells within the intralobular septae and the subcapsular cortex, which are regions where the triple-negative thymocytes are also localized. These data provide evidence that the c-kit receptor is present on human hematopoietic bone marrow and intrathymic T cell progenitor cells, and that it likely plays a role in early T cell lymphopoiesis.
 ...
PMID:The c-kit proto-oncogene receptor is expressed on a subset of human CD3-CD4-CD8- (triple-negative) thymocytes. 752 82

The generation of murine mast cells is supported by several cytokines, and mast cell lines are frequently established in long-term cultures of normal murine marrow cells. In contrast, growth of human mast cells was initially dependent on coculture with murine fibroblasts. The growth factor produced by murine fibroblasts and required to observe differentiation of human mast cells is attributable in part to stem cell factor (SCF). However, other factors are likely involved. We have previously shown that the combination of SCF and interleukin-3 (IL-3) efficiently sustains proliferation and differentiation of colony-forming cells (CFCs) from pre-CFC enriched from human umbilical cord blood by CD34+ selection. With periodic medium changes and the addition of fresh growth factors, five consecutive cultures of different cord blood samples gave rise to differentiated cells and CFCs for more than 2 months. Although differentiated cells continued to be generated for more than 5 months, CFCs were no longer detectable by day 50 of culture. The cells have the morphology of immature mast cells, are Toluidine blue positive, are karyotypically normal, are CD33+, CD34-, CD45+, c-kit-, and c-fms-, and die in the absence of either SCF or IL-3. These cells do not form colonies in semisolid culture and are propagated in liquid culture stimulated with SCF and IL-3 at a seeding concentration of no less than 10(4) cells/mL. At refeedings, the cultures contain a high number (> 50%) of dead cells and have a doubling time ranging from 5 to 12 days. This suggests that subsets of the cell population die because of a requirement for a growth factor other than SCF or IL-3. These results indicate that the combination of cord blood progenitor and stem cells, plus a cocktail of growth factors including SCF and IL-3, is capable with high efficiency of giving rise in serum-deprived culture to human mast cells that behave like factor-dependent cell lines. These cells may represent a useful tool for studies of human mast cell differentiation and leukemia.
 ...
PMID:Long-term generation of human mast cells in serum-free cultures of CD34+ cord blood cells stimulated with stem cell factor and interleukin-3. 752 46

Aggregation of the receptor with high affinity for IgE (Fc epsilon RI) on the surface of mast cells and basophils stimulates phosphorylation of protein tyrosines, a process in which p53/56lyn kinase has been implicated. We measured the association between Fc epsilon RI and the kinase, using chemical crosslinking to stabilize their interaction. In the rat basophilic leukemia mast cell line, 3-4%, and at most 20%, of Fc epsilon RI appear to be associated with the kinase prior to aggregation, even though there is an excess of total cell lyn kinase. Aggregating the Fc epsilon RI causes three to four times more of the kinase to associate with receptors, a process requiring a prior phosphorylation step. In an in vitro assay, the lyn associated with the aggregated receptors becomes disproportionately more phosphorylated than would be predicted from the amount of lyn associated with the receptors. These and other data are consistent with a model in which aggregation of the receptor leads to its transphosphorylation by constitutively associated lyn kinase. We propose that additional molecules of this kinase are thereby recruited and that this markedly enhances transphosphorylation of tyrosine on the receptor and associated proteins, thereby initiating a cascade of further biochemical changes. This model is also consistent with data on receptors such as the clonotypic receptors on B and T lymphocytes, which share structural and functional features with Fc epsilon RI.
 ...
PMID:Aggregation of the high-affinity IgE receptor and enhanced activity of p53/56lyn protein-tyrosine kinase. 752 94


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>