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

Previous studies have shown that matrix vesicles isolated from cultures of costochondral growth zone chondrocytes and treated with 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] can activate recombinant human latent transforming growth factor beta1 (rhTGF-beta1). It is unknown what enzyme or other factor in the extracellular organelles is responsible for the activation. This study tested the hypothesis that enzymes present in matrix vesicles can activate latent TGF-beta1 and that this is regulated by 1alpha,25(OH)2D3. To do this, we examined the ability of matrix vesicle extracts to activate small latent rhTGF-beta1. In addition, enzymes previously determined to be present in matrix vesicles were screened for their ability to activate small latent rhTGF-beta1. Recombinant human matrix metalloproteinase 2 (rhMMP-2; 72 kDa gelatinase), rhMMP-3 (stromelysin 1), purified human plasminogen, and purified urokinase (plasminogen activator) were each tested at varying concentrations. To assess the role of cell maturation, we used a cell culture model in which chondrocytes are derived from two distinct zones of rat costochondral cartilage, the resting zone and the growth zone. Matrix vesicles were isolated from these cultures and then tested. The results showed that extracts of matrix vesicles produced by both growth zone and resting zone chondrocytes were able to activate small latent rhTGF-beta1. The effects were dose and time dependent, with greater activity being found in extracts of matrix vesicles from the growth zone chondrocyte cultures. Only rhMMP-3 was able to activate small latent rhTGF-beta1, indicating that stromelysin-1, but not MMP-2, plasminogen, or urokinase, was involved. As observed in the extracts, the effect of rhMMP-3 was time and dose dependent. When anti-MMP-3 antibody was added to matrix vesicle extracts from both cell types, activation of small latent rhTGF-beta1 was dose-dependently blocked. Neither 1alpha,25(OH)2D3 nor 24R,25(OH)2D3 had a direct effect on activation of small latent rhTGF-beta1 by the extracts. However, when intact matrix vesicles were treated with 1alpha,25(OH)2D3, their ability to activate small latent rhTGF-beta1 was increased. Inhibition of phospholipase A2 with quinacrine blocked the 1alpha,25(OH)2D3-dependent effect. These results suggest that the ability of 1alpha,25(OH)2D3-treated matrix vesicles to activate small latent TGF-beta1 is via action of the secosteroid on the matrix vesicle membrane, not on the enzymes responsible for activating latent TGF-beta1. Because matrix vesicles isolated from growth zone chondrocytes have been shown to contain increased phospholipase A2 activity after treatment with 1alpha,25(OH)2D3, it is likely that this secosteroid promotes loss of membrane integrity through phospholipase A2-dependent formation of lysophospholipids, resulting in the release of MMP-3 into the matrix, where latent TGF-beta1 is stored. Taken together, the results of the current study show that matrix vesicles produced by growth plate chondrocytes contain MMP-3, that this enzyme is at least partially responsible for activation of small latent TGF-beta1 in the matrix, and that 1alpha,25(OH)2D3 regulates MMP release from matrix vesicles.
 ...
PMID:Activation of latent transforming growth factor beta1 by stromelysin 1 in extracts of growth plate chondrocyte-derived matrix vesicles. 1145 Jul 4

Proteolytic degradation of the extracellular matrix is essential to angiogenesis. Two families of proteases, the serine proteases of plasminogen activator/plasmin system and the matrix metalloproteinases (MMPs) are closely involved in these processes. The treatment of mice with a diet containing a new synthetic MMP inhibitor, OPB-3206: 3S-[4-(N-hydroxyamino)-2R-isobutylsuccinyl] amino-1methoxy-3, 4-dihydrocarbostyril, abrogated the development of new vessels in a rat corneal assay, and in a mouse Matrigel assay. In an in vitro angiogenesis model, OPB-3206 inhibited the migration and the tube formation of bovine aortic endothelial cells at 10-100 times lower concentrations than those required to inhibit the growth of these cells. OPB-3206 as well as other MMP inhibitory drugs, batimastat/BB-94 and marimastat/BB-2516, also selectively inhibited tubular morphogenesis in vitro. OPB-3206 reduced the activities of interstitial collagenase and type IV collagenase, but the concentrations of 50% inhibition against these MMPs were much higher than those of BB-94 and BB-2516. However, this new compound also inhibited urokinase type plasminogen activator activity on fibrin zymogram, while BB-94 and BB-2516 did not. Furthermore, the addition of urokinase type plasminogen activator reduced the inhibitory effect of the tubular morphogenesis of vascular endothelial cells by OPB-3206. The treatment of mice with a diet containing this new compound also reduced the growth of implanted mammary carcinomas as well as the lung metastasis of colon carcinoma. The anti-angiogenic effect of OPB-3206 appeared to be associated with its inhibition of tumor growth and metastasis.
 ...
PMID:A new synthetic matrix metalloproteinase inhibitor modulates both angiogenesis and urokinase type plasminogen activator activity. 1451 52

Fresh-frozen plasma (FFP) was evaluated for gelatinolytic and fibrinolytic activity. Gelatin zymography revealed that gelatinase A (MMP-2) was constitutively present in FFP whereas gelatinase B (MMP-9) was present at variable levels. The presence of MMP-9 likely represents differential release from neutrophils during FFP collection or processing. Although fibrin matrices generated from FFP or freshly prepared plasma contained characteristic crosslinked gamma-gamma dimers and beta-monomers, matrices generated from FFP were resistant to spontaneous plasmin-dependent fibrinolysis. This observation likely stems from the plasminogen activator instability and could potentially lead to a hypofibrinolytic state. The impact of these in vitro findings to protease balance in patients receiving multiple FFP doses remains to be determined.
 ...
PMID:Gelatinolytic and fibrinolytic activity in fresh-frozen plasma. 1515 89

Phellinus linteus (PL) is a fungus mainly found in tropical America, Africa and Asian countries including Korea, Japan and China. PL has been traditionally used for the treatment of arthritis, liver damage and cancer. However, little was known on the biological activity and characterization of Phellinus species in Cambodia. Thus, in the present study, the anti-metastatic mechanism of aqueous extract of Cambodian Phellinus linteus (CPL) was evaluated. Cambodian mushroom was identified as a Phellinus species with 99% homology of Phellinus linteus by DNA sequence analysis and comparison by the National Center for Biotechnology Information. CPL did not exhibit any significant cytotoxicity against B16BL6 cells, invasive melanoma cells at 1 mg/ml. However, CPL inhibited platelet aggregation induced by B16BL6 cells and also disrupted the adhesion to gelatin and invasion of B16BL6 cells in a concentration dependent manner. Similarly, CPL dose-dependently inhibited the pulmonary metastatic colonies in C57BL/6 mice intravenously injected by B16BL6 cells up to 55.5% at a dose of 50 mg/kg compared with untreated control. CPL also down-regulated the expression of urokinase type plasminogen activator (uPA), one of key proteins associated with invasion and metastasis of tumor cells in a concentration dependent fashion, while CPL didn't significantly affect the expression of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) by reverse transcriptase-polymerase chain reaction (RT-PCR). Taken together, these findings indicate that Cambodian Phellinus linteus may inhibit metastasis at least partly via regulation of uPA associated with tumor cell induced platelet aggregation (TCIPA) and also suggest a further study for isolation of active ingredients and the involvement of adhesion molecule signaling pathway.
 ...
PMID:Cambodian Phellinus linteus inhibits experimental metastasis of melanoma cells in mice via regulation of urokinase type plasminogen activator. 1563 58

In the rat, the decidual tissue is an important component for maternal recognition of pregnancy. Decidualization can be induced by either the implantation of the blastocyst or by artificial stimuli. The process of decidua formation or decidualization, is characterized by growth and differentiation of endometrial stromal cells. Prostaglandin F2alpha (PGF2alpha) has been shown to be involved in inhibition of implantation, alteration of embryo development, induction of luteal regression, and the mediation of pregnancy loss induced by microorganism infections. In order to establish a direct role for PGF2alpha in decidual function, we have evaluated its effects on the expression of an extensive array of genes using primary decidual cell culture. Upon treatment with PGF2alpha sixty genes were significantly down-regulated whereas only six genes were up-regulated (from a total of 1176 genes studied). Interestingly, the majority of the genes inhibited by PGF2alpha are either directly or indirectly involved in the turnover of the extracellular matrix (ECM). Genes such as gelatinase A (MMP2), cathepsin L, tissue inhibitor metalloproteinases 2 (TIMP2) and 3 (TIMP3), plasminogen activator inhibitor1 (PAI1), tissue type plasminogen activator (tPA), urokinase plasminogen activator (tPA), endothelin 1, calponin, carboxypeptidase D and calponin acidic were down regulated. The opposite effect was observed for prostromelysin 53 kDa (proMMP3), plasma proteinase I alpha and alpha 1 antiproteinase, all of which were significantly up-regulated by PGF2alpha. The results strongly suggest that the abortificient role of elevated levels of PGF2alpha after implantation is due, in large part, to inhibition of genes involved in the normal turnover of the extracellular matrix necessary for decidual formation.
 ...
PMID:PGF2alpha induced differential expression of genes involved in turnover of extracellular matrix in rat decidual cells. 1564 43

Evidence suggests that fibrin deposit is related to severity of glomerulonephropathy. Fibrin is considered to play an active role beyond a haemostatic plug or temporary matrix in response to injury. We have reported that fibrin induced specific morphological changes and up-regulated intercellular adhesion molecule-1 expression of glomerular endothelial cells (GECs). Changes of gelatinases activity have been implicated playing a prominent role in glomerular diseases involving matrix turnover. This study examined whether overlying fibrin influences the expression of gelatinase A and B in cultured human GECs and mechanism underlying the activation. No gelatinase activity was detectable in supernatant of cultured GECs; however, physiological concentration of fibrin (0.5-2.0 mg/ml) induced a dramatic expression of activated MMP-2 and MMP-9 at both mRNA and protein level in a dose and time dependent manner. Increased mRNA level of membrane-type 1 matrix metalloproteinases (MT1-MMPs) was also found. Interestingly, we observed that fibrin also induced the expression of tissue type plasminogen activator (tPA), urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor-1 by casein zymographic and reverse zymographic analysis. Fibrin plate assay revealed the net activity was PA predominant. Serine protease inhibitor aprotinin blocked the conversion of pro-gelatinase A and B to their active forms. The results demonstrate that overlying fibrin increased the secretion of gelatinase A and B from GECs. PA/plasmin proteolytic pathways contributed to the activation of gelatinases.
 ...
PMID:Activation of gelatinases by fibrin is PA/plasmin system-dependent in human glomerular endothelial cells. 1613 29

Kaposi's sarcoma (KS) is a highly angiogenic lesion frequently associated with acquired immune deficiency syndrome. Histologically the lesions appear to contain proliferative 'spindle shaped' cells with a mixed smooth muscle-endothelial-fibroblastic histotype and a conspicuous neovascularization, derived from host cell recruitment. Media conditioned by cultured KS cells (KS-CM) have angiogenic properties. KS-CM is able to promote endothelial and smooth muscle cell migration and invasion. The mechanisms of this KS-CM activity are still unknown. We hypothesize that KS-CM contains numerous factors with different roles in inducing the neo angiogenic process. We show that AIDS-IST-KS cell supernatants induce gelatinase A production and plasminogen activator (PA) up-regulation in vascular cells. KS-CM activity in vivo is heparin dependent. Also bFGF alone, a heparin dependent factor, alone can induce endothelial and smooth muscle cell invasion, MMP-2 production and PA activity. However, antibodies to bFGF do not block KS-CM activity and do not reduce the effect on PA up-regulation. This evidence suggests that heparin-binding factors other than bFGF may be present. Chromatography of KS-CM on heparin-sepharose demonstrates the presence of two heparin-binding fractions with chemotactic and gelatinase A inducing activity. The flow through was also active. KS-CM absorption on heparin-sepharose beads did not modify its induction of PA activity, further evidence for the presence of non heparin-binding factors as well.
 ...
PMID:Mechanisms of kaposis-sarcoma cell supernatant-induced vascular cell invasion. 2155 68


<< Previous 1 2 3 4