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)

The reactive-site sequence of a proteinase inhibitor can be written as . . . -P3-P2-P1-P'1-P'2-P'3- . . . , where-P1-P'1-denotes the reactive site. Three semisynthetic homologues have been synthesized of the bovine trypsin-kallikrein inhibitor (Kunitz) with either arginine, phenylalanine or tryptophan in place of the reactive-site residue P1, lysine-15. These homologues correspond to gene products after mutation of the lysine 15 DNA codon to an arginine, phenylalanine or tryptophan DNA codon. Starting from native (virgin) inhibitor, reactive-site hydrolyzed, still active (modified) inhibitor was prepared by chemical and enzymic reactions. Modified inhibitor was then converted into inactive des-Lys15-inhibitor by reaction with carboxypeptidase B. Inactive des-Lys15-inhibitor was reactivated by enzymic replacement of the P1 residue according to Leary and Laskowski, Jr. The introduction of arginine was catalyzed by an inverse reaction with carboxypeptidase B, while phenylalanine or tryptophan were replaced by carboxypeptidase A. The reactivated semisynthetic inhibitors were trapped by complex formation with either trypsin or chymotrypsin. The enzyme - inhibitor complexes were subjected to kinetic-control dissociation, and the semisynthetic virgin inhibitors were isolated. The inhibitory properties of the semisynthetic inhibitors have been investigated against bovine trypsin and chymotrypsin and against porcine pancreatic kallikrein and plasmin. The homologues with either lysine or arginine in the P1 position are equally good inhibitors of trypsin, plasmin and kallikrein. The Arg-15-homologue is a slightly more effective kallikrein inhibitor than the Lys15-inhibitor. The semisynthetic phenylalanine and tryptophan homologues, however, are weak inhibitors of trypsin and still weaker inhibitors of kallikrein, but are excellent inhibitors of chymotrypsin. Their association constant with chymotrypsin is at least ten times higher than that of native Lys-15-inhibitor. A dramatic specificity change is observed with the phenylalanine and tryptophan homologues, which in contrast to the native inhibitor do not at all inhibit porcine plasmin. Thus, the nature of the P1 residue strongly influences the primary inhibitory specificity of the bovine inhibitor (Kunitz).
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PMID:Replacement of lysine by arginine, phenylalanine and tryptophan in the reactive site of the bovine trypsin-kallikrein inhibitor (Kunitz) and change of the inhibitory properties. 12 27

The effect of mast cell activation and degranulation on the proliferation in the intact mesentery was studied in Sprague-Dawley rats. Mast cell activation was achieved by a single intraperitoneal injection of Compound 48/80. The proliferation was studied using three independent methods for estimation of cell production and DNA synthesis: 1. the mitotic index, 2. the relative number of cells having a DNA content in the S and G2 regions, by Feulgen photometric measurement in individual cells, and 3. the specific DNA activity, employing a method which combines a liquid scintillation technique after an intravenous injection of 3H-thymidine and Feulgen photometric determination of the DNA content per membrane preparation. It was found that the proliferation of the normal mesenchymal cells adjacent to the activated and degranulated mast cells in the mesentery was significantly increased within 24 and 32 h, the maximum increase being more than 20-fold compared to untreated controls. The results suggest that the common type of mast cell may have a pathophysiological function related to stimulation of local cell proliferation.
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PMID:Mast cell activation and tissue cell proliferation. 95 59

Cytofluorometric signals derived from some frequently used fluorophores were studied during illumination times in the millisecond range. These rapid signals were recorded on a storage oscilloscope. The objects studied included (1) Berberine sulphate stained mast cell heparin, (2) Acriflavine-Feulgen stained DNA, (3) Acridine orange stained mast cell heparin, (4) Acridine orange stained DNA and (5) Fluorescein isothiocyanate-conjugated IgG in an antinuclear factor test. A new rapid fading phenomenon, appearing as an initial peak upon the familiar slowly declining fluorescence signal, is reported. This fading, which had a duration of about 10 ms, also showed a very rapid recovery. The influence of this phenomenon on fluorometric measurement techniques is discussed. The millisecond fading phenomenon occurred in all the fluorophores studied except Fluorescein isothiocyanate-conjugated IgG. In the case of acridine orange the phenomenon was present when the dye was bound to nuclear DNA but absent when the dye was bound to mast cell heparin. This suggests that the millisecond fading and recovery phenomenon may be used in fluorescent microprobe studies.
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PMID:Millisecond fading and recovery phenomena in fluorescent biological objects. 108 96

In the course of experiments on the role of the COOH-terminal residues in pancreatic deoxyribonuclease, we undertook to ascertain whether the presence of sodium dodecyl sulfate would render the normally unavailable terminus susceptible to hydrolysis by carboxypeptidase A. When DNase A is dissolved in 0.005% sodium dodecyl sulfate the protein becomes enzymically inactive when assayed against DNA in the same sodium dodecyl sulfate concentration. The loss of activity caused by treatment with sodium dodecyl sulfate for 1 hour at 45 degrees can be fully restored if the detergent-containing solution is diluted 10-fold into 6 M guanidinium chloride and then 10-fold into a pH 7.0 buffer, 10 mM in CaCl2, prior to a 100-fold dilution for assay. The presence of Ca2+ is essential for the refolding process. If the same degree of dilution is made into sodium dodecyl sulfate-free buffer without the guanidinium chloride step, there is very little reversal of the inactivation. An almost complete loss of regenerable activity is caused by 1 hour of digestion by carboxypeptidase at 45 degrees in the presence of 0.03% sodium dodecyl sulfate. Although up to 6 amino acid residues can be removed from the COOH terminus, the loss of activity can be correlated with the removal of either 1 or 2 amino acid residues (-Leu-Thr) from the COOH-terminal sequence. Thus, DNase A is one of the several enzymes in which residues at the COOH terminus are essential to the active conformation. If the enzyme minus 2 to 6 terminal residues was mixed with a 15-residue COOH-terminal peptide (obtained by cyanogen bromide cleavage), only about 2% activity could be regenerated.
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PMID:Reversible inactivation of pancreatic deoxyribonuclease A by sodium dodecyl sulfate. Removal of COOH-terminal residues from the denatured protein by carboxypeptidase A. 116 40

We have previously shown the development in vitro of tryptase+ human mast cells from fetal liver cells cocultured with murine 3T3 fibroblasts. In this study, recombinant human stem cell factor (rhuSCF), the ligand for the c-kit proto-oncogene product called Kit, stimulated the growth and differentiation primarily of mast cells from dispersed fetal liver cells, whereas recombinant human interleukin-3 (rhuIL-3) stimulated the differentiation of basophils along with other cell types. Cultures of fetal liver cells were initiated and maintained in the presence of rhuSCF or rhuIL-3 for up to 6 weeks. Metachromatic cells in cytospins were identified as mast cells primarily on the basis of tryptase expression, and as MCT or MCTC by immunohistochemistry using monoclonal antibodies against tryptase and chymase, whereas basophils were metachromatic, polymorphonuclear, and lacked these proteases. Levels of tryptase and histamine were measured by radioimmunoassay, tryptase and chymase activities by peptide hydrolysis, and cell surface Kit by flow cytometry with the monoclonal antibody YB5.B8. The predominant presence of mast cells occurred only in the cultures supplemented with rhuSCF. The percentage and total number of mast cells increased over time with increasing concentrations of rhuSCF and reached a plateau at 55 ng/mL. At this concentration of rhuSCF, mast cells first appeared by day 7; by day 42, 106% of the starting number of cells were present and 85% of these were tryptase+, 31% being weakly chymase+. These mast cells appeared immature by ultrastructural criteria; most cells were mononuclear, but some had nuclei with deeply divided lobes. DNA synthesis in tryptase+ mast cells at days 21 and 28 of culture with rhuSCF was demonstrated by incorporation of bromodeoxyuridine. Calculated levels of histamine (1.2 pg/mast cell) and tryptase (0.9 pg/mast cell) were similar to those determined previously in coculture experiments with murine 3T3 fibroblasts. Chymase activity was undetectable in most cell extracts. On day 0, 4% to 20% of fetal liver cells expressed cell surface Kit. In the presence of rhuSCF, the percentages and total numbers of Kit+ cells and the apparent concentration of Kit per cell increased along with the number of tryptase+ cells. In the presence of rhuIL-3, toluidine blue+, tryptase- cells first and maximally appeared at day 14 (11% +/- 2.5%). The percentage of these toluidine blue+ cells then declined to about 6% by days 21 and 35, while the total number of positive cells declined over 10-fold. Kit+ cells in the presence of rhuIL-3 declined from 9% on day 3 to 2% on day 35.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Recombinant human stem cell factor stimulates differentiation of mast cells from dispersed human fetal liver cells. 128 84

The HB4C5 and HF10B4 cell lines are human-human hybridomas producing human IgM monoclonal antibodies (MAbs) reactive to porcine carboxypeptidase A (CPase), but not to double stranded DNA (ds DNA). We obtained G418-resistant HB4C5 and HF10B4 cells by an introduction of pSV2-neo DNA. Almost all of the G418-resistant clones produced MAbs reactive to not only the CPase but the ds DNA. The results of the inhibition ELISA suggested that the cross-reactivity of the antibodies from G418-resistant clones to CPase and ds DNA was responsible for the alteration on their antigen specificity. HB4C5 and HF10B4 cells and their G418-resistant clones produced antibodies having glycosylated lambda chain. The antibodies produced by tunicamycin-treated G418-resistant subclones of HB4C5 and HF10B4 lost the ability to bind to ds DNA, but retained the ability to bind to CPase. These results suggest that an introduction of pSV2-neo DNA into these hybridomas alters the specificities of their MAbs, and that the alteration to antigen binding specificities of their MAbs may be associated with glycosylation of the MAbs by these hybridomas.
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PMID:Altered reactivity of immunoglobulin produced by human-human hybridoma cells transfected by pSV2-neo gene. 136 45

Agents derived from mast cell granule constituents, and compound 48/80 which stimulates release of mast cell granules, have been used by us to develop new methods for quantitating angiogenesis in the chick chorioallantoic membrane. Two of these methods provide different insights, demonstrating different patterns of response to dosage and over time, produced by different agents. Counting mesenchymal blood vessels is convenient for obtaining dose-response data. Histamine and compound 48/80 have been shown previously to give a sigmoid dose-response curve resulting in a plateau before the lethal dose. This contrasts with the effect of porcine sodium heparin (Evans Biologicals) which results in a minor increase then a relative decline in vessel number due to a failure of growth. Here, the ability to produce angiogenesis or antiangiogenesis appears to be dose-dependent. Measurement of the changes in DNA synthesis, leading to visible angiogenesis, may be performed once the optimal angiogenic dose is known, and again distinctive patterns of response with different agents have been found. Histamine results in a fall then rise to a peak at 36 hr. We now show that two types of heparin each produce a peak at 12 hr. Compound 48/80 results in a distinctive pattern that looks like a composite of the histamine and especially the heparin effects, and this suggests that both are relevant to induction of angiogenesis by mast cells. The elicitation of this pattern of response also provides a method, additional to electron microscopy, for discovering whether or not an angiogenic substance is likely to operate via mast cell stimulation. Such characteristic patterns offer a new way of classifying angiogenic substances.
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PMID:Patterns of angiogenic response to mast cell granule constituents. 137 83

Investigations of mast cell biology have often used immortalized cultured cells which are continuously proliferating. In vivo, however, only 2% or fewer tissue mast cells are actively dividing. We used aphidicolin, an inhibitor of DNA polymerase to induce a proliferative arrest of murine mast cells characterized by an inhibition of cell division and thymidine incorporation, with accumulation of cells in G1 and early S phase of the cell cycle. Uridine incorporation and cell viability were not significantly impaired. DNA synthesis and cell division both resumed rapidly upon removal of the drug. Morphometric analysis demonstrated that cell size, granule size, and number of granules per cell were all increased in aphidicolin-treated cells. Proliferative arrest also produced a 14-fold increase in cellular histamine content, but did not alter the proteoglycans synthesized by the cell. The level of c-myc mRNA was reduced in aphidicolin-arrested cells, but returned to the level observed in untreated cells within 1 hr of removal of the drug. In contrast, the constitutive steady-state RNA levels of tumour necrosis factor-alpha (TNF-alpha), B2-microglobulin, actin, and the c-Ha-ras and c-fes protooncogenes were not altered. Aphidicolin-induced proliferative arrest did not prevent the induction of TNF-alpha, interleukin-6 (IL-6) and c-fos genes in response to calcium ionophore. Both the magnitude and induction kinetics of these messages were similar in aphidicolin-treated and untreated cells. We conclude that proliferative arrest results in morphological and biochemical changes suggestive of cellular maturation, but inhibition of cell division alone is not sufficient to alter mast cell phenotype. Although optimal c-myc expression appears to require active proliferation, cytokine gene induction can occur in non-dividing cells. These data suggest that the proliferative quiescence of in vivo mast cells should not preclude their involvement in biological events via elaboration of multi-functional cytokines.
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PMID:Aphidicolin-induced proliferative arrest of murine mast cells: morphological and biochemical changes are not accompanied by alterations in cytokine gene induction. 138 41

The immunosuppressive drugs FK506 and cyclosporin A have an identical spectrum of activities with respect to IgE receptor (Fc epsilon RI)-mediated exocytosis from mast cells and T cell receptor-mediated transcription of IL-2. These findings suggest a common step in receptor-mediated signal transduction leading to exocytosis and transcription and imply that immunosuppressive drugs target specific signal transduction pathways, rather than specific cell types. This hypothesis is supported by studies on the effect of rapamycin on IL-3 dependent proliferation of the rodent mast cell line PT18. Rapamycin inhibits proliferation of PT18 cells, achieving a plateau of 80% inhibition at 1 nM. This inhibition is prevented in a competitive manner by FK506, a structural analogue of rapamycin. Proliferation of rat basophilic leukemia cells and WEHI-3 cells was also inhibited, at doses comparable to those shown previously to inhibit IL-2-dependent proliferation of cytotoxic T lymphocyte line (CTLL) cells. In contrast, proliferation of A-431 cells, a epidermoid cell line, was not affected by rapamycin. DNA histograms indicate that complexes formed between the rapamycin-FK506-binding protein (FKBP) and rapamycin arrest-proliferating PT18 cells in the G0/G1-phase. It is concluded that FKBP-rapamycin complexes may inhibit proliferative signals emanating from IL-3 receptors, resulting in growth arrest of cytokine-dependent, hematopoietic cells.
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PMID:The effect of the immunophilin ligands rapamycin and FK506 on proliferation of mast cells and other hematopoietic cell lines. 138 15

GATA-1, a transcription factor of the 'zinc-finger' family, is required for the development of mature erythroid cells and is also highly expressed in the megakaryocytic and mast cell lineages. The helix-loop-helix gene SCL (or TAL) is expressed in the same three hematopoietic lineages as GATA-1. To explore the role of GATA-1 and SCL in hematopoietic differentiation, we introduced a new expression vector bearing each gene into the early myeloid cell line 416B, which could originally differentiate in vivo along the megakaryocytic and granulocytic lineages. Enforced expression of SCL at high levels did not provoke differentiation, but GATA-1 induced the appearance of megakaryocytes as assessed by morphology, the presence of acetylcholinesterase and a polyploid DNA content. Although GATA-1 is thought to stimulate its own transcription in erythrocytes, expression of the endogenous gene was not increased in the megakaryocytic lines; hence GATA-1 may not be autoregulatory in this lineage. Megakaryocytic differentiation was accompanied by a marked decrease in the myeloid surface marker Mac-1. The absence of mast cell or erythroid differentiation suggests that GATA-1 may not be sufficient to provoke maturation along these lineages or that these pathways are impeded in 416B cells. These results demonstrate that a member of the GATA gene family can act as an important regulator of megakaryocytic differentiation.
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PMID:GATA-1 but not SCL induces megakaryocytic differentiation in an early myeloid line. 138 17


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