Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When confluent keratinocyte cultures were wounded by cutting with a blade, the cells rapidly retracted from the wounded site, leaving an area denuded of cells. Within 3-4 h of wounding, keratinocytes began to migrate from the edges and gradually reepithelialized the entire denuded area. Mitomycin C did not prevent the reepithelialization but did dramatically inhibit [3H]thymidine incorporation into the leading edge of cells. These results indicate that cell proliferation was not required for reepithelialization. Using a rabbit antibody against urokinase-type plasminogen activator (u-PA) and an avidin-biotin-peroxidase detection method, we localized u-PA in the keratinocytes at the leading edge of the migrating cultures. Cytochalasin B dramatically inhibited the extent of migration and also altered cell morphology; nonetheless, urokinase was detected in the limited number of cells that moved into the wounded area, even in the presence of cytochalasin B. A small but consistent enhancement (36% +/- 9) of plasminogen activator activity was observed in the supernatant of wounded cultures. These data suggest that plasminogen activator may be involved in the migration of keratinocytes that occurs during wound healing.
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PMID:Migrating keratinocytes express urokinase-type plasminogen activator. 243 17

The relation of in vitro properties to tumorigenicity was studied using eight sublines of the human breast cancer cell line MCF-7. Four of the eight were tumorigenic in estrogen-treated nude mice. The sublines differed for each of the in vitro properties measured, and no property correlated perfectly with tumorigenicity. Cytochalasin B-induced multinucleation was a property of all four tumorigenic sublines but of only one of the four nontumorigenic ones. Anchorage-independent growth and concanavalin A-mediated hemadsorption levels were higher in all sublines than reported levels for nontransformed fibroblasts and normal human or mouse mammary epithelial cells. The production of both plasminogen activator and a plasminogen-independent fibrinolytic activity showed no relationship to tumorigenicity but was higher in those sublines producing more invasive tumors. It appears that no one of these in vitro properties is sufficient to make a subline tumorigenic. Rather, the first three properties studied here and, perhaps, also production of plasminogen activator may each be necessary, but not sufficient, to make a subline tumorigenic. In addition, properties such as production of plasminogen activator and other proteases, while perhaps not essential to tumorigenicity, may confer characteristics, such as invasiveness, on the tumors produced by a given subline.
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PMID:Relation of in vitro properties to tumorigenicity for a series of sublines of the human breast cancer cell line MCF-7. 377 50

We have determined that the interaction of IgG-coated erythrocytes (EIgG) and complement-coated erythrocytes (EIgMC) with macrophage Fc and complement receptors, respectively, modulates the secretion of the neutral proteinases, elastase, and plasminogen activator. EIgG binding and ingestion stimulated secretion of elastase and plasminogen activator less than or equal to 6-fold and 20-fold, respectively, over the 3 d following treatment. Stimulation was dependent on the IgG titer bound to each erythrocyte and was detectable at greater than 6.2 X 10(3) molecules IgG/ erythrocyte (total 0.99 nM IgG in the culture). Cytochalasin B did not inhibit stimulation, indicating that the ingestion of ligands was not necessary. Binding of EIgG to the three subclass-specific Fc receptors (IgG2a, IgG2b/IgG1, IgG3) was effective. Stimulation of elastase secretion required continued exposure of ligands to cells for up to 24 h, whereas production of plasminogen activator, which has plasma membrane-bound forms as well as secreted forms, was stimulated by exposure for 2 h. The stimulated production of elastase and plasminogen activator by triggering Fc receptors was seen only when the initial secretion rates were low. Periodate- or thioglycollate-elicited macrophages, which have high rates of proteinase secretion, were not stimulated further. EIgMC, which are bound but not ingested by resident macrophages, stimulated elastase secretion transiently, and the rate of secretion returned to the control level by 24 h. Therefore, the mode of stimulation of neutral proteinase secretion by complement receptor differed from that of Fc receptor; stimulation by complement receptor possibly involves a limited release of enzyme from intracellular stores, rather than stimulating accelerated synthesis of enzyme. Erythrocytes coated with both complement and IgG showed both the transient increase in elastase typical of complement-mediated secretion and the sustained increase typical of Fc receptor-mediated secretion. These results suggest that macrophage Fc and complement receptors regulate secretion of proteinases by receptor-specific mechanisms.
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PMID:Regulation of elastase and plasminogen activator secretion in resident and inflammatory macrophages by receptors for the Fc domain of immunoglobulin G. 622 94