Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The urokinase-type plasminogen activator receptor (u-PAR) facilitates extracellular matrix degradation in part by accelerating plasmin formation at the cell surface. We previously reported that u-PAR expression is elevated in colon cancer cell lines characterized by their in vitro invasive capacity. Since, u-PAR expression is increased by a variety of growth factors, which signal through the extracellular signal-regulated kinases 1 and 2 (ERK1/ERK2), we determined if these mitogen-activated protein kinases (MAPKs) regulate u-PAR expression in two cultured colon cancer cell lines. An in-gel kinase assay showed that ERK1 activity was considerably higher in RKO cells, which display > or = 10(5) receptors/cell, than the GEO cells which have approximately 10(4) urokinase receptors per cell. The expression of either an ERK-inactivating phosphatase (CL100), or a kinase-defective ERK1, decreased the activity of a u-PAR promoter-driven CAT reporter in RKO cells. Immune complex kinase assays indicated that the constitutive ERK1 activity in RKO cells was largely a result of an activated MEK1. Further, treatment of RKO cells with a specific inhibitor (PD 098059) of MEK1 activation, which diminished ERK1 activity, reduced the amount of urokinase specifically bound to the cell surface and this was associated with reduced laminin degradation. The expression of a dominant negative c-Raf-1 also reduced u-PAR promoter activity suggesting that MEK1 activation involved an activator at, or upstream, of this serine-threonine kinase. Transfection of the u-PAR-deficient GEO cells with a constitutively activated MEK1 expression construct up-regulated u-PAR promoter activity. Similarly treatment of GEO cells with a phosphatase inhibitor (sodium vanadate) caused a dose-dependent increase in ERK1 activity which paralleled increased cell surface binding of urokinase. Taken together, these data suggest that elevated u-PAR expression, in at least a sub-population of colon cancer, is partly a consequence of a constitutively activated ERK-1-dependent signaling cascade.
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PMID:Elevated urokinase-type plasminogen activator receptor expression in a colon cancer cell line is due to a constitutively activated extracellular signal-regulated kinase-1-dependent signaling cascade. 919 Oct 56

We have previously reported the discovery of VEGF183, a novel isoform of vascular endothelial growth factor (VEGF), whose nucleotide sequence revealed an 18-bp deletion in the exon 6A-encoded region of VEGF. The following study was done to characterize VEGF183 and to determine its biological activity in vitro and in vivo. Recombinant human VEGF183 was expressed in Escherichia coli (rhVEGF183) or in human 293 embryonic kidney cells (293-VEGF183) and tested for stimulation of permeability of dermal vessels in normal rats as well as for mitogenic activity and phosphorylation of mitogen-activated protein kinases (MAPK) in cultured human umbilical vein endothelial cells (HUVECs). While small amounts of VEGF183 were secreted into the conditioned media (CM) of 293 cells expressing VEGF183 (293-VEGF183 cells), most of the VEGF183 remained cell surface-bound and could be released into the CM following treatment with plasmin or heparin. CM from 293-VEGF183 cells treated with heparin or plasmin induced about a twofold increase in cell numbers and stimulated MAPK phosphorylation in HUVECs as compared with CM from untreated 293-VEGF183 cells or from heparin- or plasmin-treated 293 cells containing the vector alone. Intradermal injections of rhVEGF183 promoted increased permeability of dermal vessels to Evan's blue dye. Our study shows that VEGF183 is predominantly a cell-anchored protein that promotes increased vascular permeability in vivo but requires extracellular cleavage or release by heparin or plasmin to promote its mitogenic activity in vitro.
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PMID:Ectodomain shedding of VEGF183, a novel isoform of vascular endothelial growth factor, promotes its mitogenic activity in vitro. 1180 42

Interferons (IFNs) are multifunctional cytokines that after binding to the cell surface receptor induce the expression of a large number of genes, which in turn, mediate many biological processes including host defense, cell growth control, signaling, and metabolism. Here we show that IFN-alpha activates the mitogen-activated protein kinases (MAPK) ERK1/2 and the transcription factor CREB/ATF-1, which lead to the alpha-enolase (alpha-ENO) gene expression in fibroblasts. Alpha-ENO mRNA accumulation was apparent 6 h post-IFN stimulation and required both de novo protein synthesis and active gene transcription, which is typical of a secondary response gene. Alpha-ENO expression does not appear to be restricted to fibroblasts, since it was equally verified in peripheral blood mononuclear cells (PBMC). Furthermore, IFN-alpha stimulates the expression of the primary response genes c-fos and egr-1, which was followed by an increase in DNA binding activity of c-FOS and EGR-1 proteins, as verified by shift assays using the cis-acting elements AP-1 and EGR-1 localized at the alpha-ENO promoter. Finally, we also demonstrated that IFN treatment of PBMC cause an increase in both, alpha-ENO expression on the cell surface and plasmin generation followed addition of exogenous plasminogen.
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PMID:Characterization of alpha-enolase as an interferon-alpha 2 alpha 1 regulated gene. 1597 May 16

Diabetic nephropathy is characterized by excessive accumulation of extracellular matrix (ECM) in the kidney. Reactive oxygen species (ROS) play a central role in the ECM synthesis and degradation in the glomeruli and tubulointerstitium leading to renal fibrosis. High glucose (HG) induces cellular ROS through protein kinase C (PKC)-dependent activation of NADPH oxidase and through mitochondrial metabolism. ROS thus generated activate signal transduction cascade (PKC, mitogen-activated protein kinases, and janus kinase/signal transducers and activators of transcription) and transcription factors (nuclear factor-kappaB, activated protein-1, and specificity protein-1), up-regulate transforming growth factor-beta1 (TGF-beta1), angiotensin II (Ang II), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor-1 (PAI-1) gene and protein expression, and promote formation of advanced glycation end-products (AGE). PKC, TGF-beta1, Ang II, and AGE also induce cellular ROS and signal through ROS leading to enhanced ECM synthesis. NF-kappaB-MCP-1 pathway is activated by ROS and promotes monocyte recruitment and profibrotic process in the kidney. HG- and TGF-beta1-induced PAI-1 up-regulation is mediated by ROS and contribute to ECM accumulation via suppression of plasmin ativity. TGF-beta1-induced myofibroblast transformation of renal tubular epithelial cells (epithelial-mesenchymal transition) is also mediated by ROS and contribute to tubulointerstitial fibrosis. In summary, ROS transduce and amplify glucose signalling in renal cells under high glucose environment and play a critical role in excessive ECM deposition in the diabetic kidney. A better understanding of ROS production and removal will allow more effective therapeutic strategies in diabetic renal and other vascular complications.
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PMID:Reactive oxygen species amplify glucose signalling in renal cells cultured under high glucose and in diabetic kidney. 1617 88

Previously we have demonstrated that both plasminogen (Plg) and plasmin (Pla) regulate the expression of the transcription factors c-FOS and EGR-1 [L.P. De Sousa, B.S. Brasil, B.M. Silva, M.H. Freitas, S.V. Nogueira, P.C. Ferreira, E.G. Kroon, C.A. Bonjardim, Plasminogen/plasmin regulates c-fos and egr-1 expression via the MEK/ERK pathway, Biochem. Biophys. Res. Commun. 329 (2005) 237-245]. Here we show that Plg activates the mitogen-activated protein kinases MEK and ERK which leads to alpha-enolase (alpha-ENO) gene expression not only in fibroblasts, but also in peripheral blood mononuclear cells. The alpha-ENO mRNA accumulation was apparent three hours post-Plg treatment and remained elevated out to 28h, a process that seems to require both de novo protein synthesis and active gene transcription. Pla mimics Plg-stimulated alpha-ENO expression through its serine protease activity, suggesting that conversion of Plg to active Pla is required. Pharmacological and genetic blockade of MEK caused inhibition of alpha-ENO mRNA accumulation, implicating MEK/ERK as the transduction pathway that leads to alpha-ENO expression upon Plg stimulation. Furthermore, Plg stimulated DNA binding activity of the transcription factors activator-protein 1 and early growth response gene-1 to their cognate regulatory sequences at alpha-ENO promoter. Altogether, our data show that Plg/Pla regulates alpha-ENO expression through the MEK/ERK pathway.
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PMID:Plasminogen/plasmin regulates alpha-enolase expression through the MEK/ERK pathway. 1622 43

ECRG2 is a novel gene that shows sequence similarity to KAZAL-type serine protease inhibitor. We have previously demonstrated that ECRG2 inhibits migration/invasion of lung cancer PG cells. However, the mechanism by which ECRG2 performs these activities is a compelling question. Urokinase-type plasmin activator (uPA) binding to uPAR induces migration/invasion through multiple interactors including integrins. In this study, we found that ECRG2 binds specifically to the kringle domain of uPA. Moreover, we demonstrated that ECRG2 forms a complex with uPA.uPAR, that such a complex modifies the dynamical association of uPAR with beta1 integrins, and that disruption inhibits Src/MAP (mitogen-activated protein) kinase pathway, resulting in suppression of cell migration/invasion in an in vitro Matrigel migration/invasion assay. Conversely, depletion of ECRG2 markedly enhanced the association of uPAR with beta1 integrins, elevated basal Src/MAP kinase activation, and stimulated HT1080, MDA-MB-231, and MCF-7 cell migration/invasion. Together, our results provide evidence that ECRG2 is involved in the regulation of migration/invasion through uPA/uPAR/beta1 integrins/Src/MAP kinase pathway and may represent a novel therapeutic target for cancer.
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PMID:ECRG2 regulates cell migration/invasion through urokinase-type plasmin activator receptor (uPAR)/beta1 integrin pathway. 1971 62

beta(2)-Glycoprotein-I (beta(2)gpI), an abundant plasma glycoprotein, functions as a regulator of thrombosis. Previously, we demonstrated that plasmin-clipped beta(2)gpI (cbeta(2)gpI) exerts an anti-angiogenic effect on human umbilical vein endothelial cells (HUVEC). The present study was focused on the molecular background responsible for this phenomenon. cbeta(2)gpI strongly reduced HUVEC growth and proliferation as evidenced by the MTT and BrdU assay and delayed cell cycle progression arresting HUVEC in the S-and G2/M-phase. Western blot analysis indicated that cbeta(2)gpI inhibited cyclin A, B and D1, and enhanced p21 and p27 expression. Activity of p38 was down-regulated independently from the cbeta(2)gpI incubation time. Phosphorylation of ERK1/2 was not changed early (30 and 60 min) but became enhanced later (90 min, 4h). JNK activity was reduced rapidly after cbeta(2)gpI treatment but compared to controls, increased thereafter. Annexin II blockade prevented growth inhibition and cell cycle delay evoked by cbeta(2)gpI. We assume that cbeta(2)gpI's effects on HUVEC growth is mediated via cyclin A, B and D1 suppression, up-regulation of p21 and p27 and coupled to modifications of the mitogen-activated protein (MAP) kinase signalling pathway. cbeta(2)gpI may represent a potential endogenous angiogenesis-targeted compound, opening the possibility of a novel tool to treat cancer.
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PMID:Plasmin-clipped beta(2)-glycoprotein-I inhibits endothelial cell growth by down-regulating cyclin A, B and D1 and up-regulating p21 and p27. 2043 5

Angiotensin II (Ang II) plays an important role in the maintenance of bone mass and integrity by activation of the mitogen-activated protein kinases (MAPKs) and by modulation of balance between resorption by osteoclasts and formation by osteoblasts. However, the role of Ang II in the turnover of extracellular matrix (ECM) in osteoid by osteoblasts remains unclear. Therefore, we examined the effect of Ang II on the expression of matrix metalloproteinases (MMPs), plasminogen activators (PAs), and their inhibitors [i.e., tissue inhibitors of metalloproteinases (TIMPs) and PA inhibitor-1 (PAI-1)] using osteoblastic ROS17/2.8 cells. Treatment with Ang II strikingly increased the expressions of MMP-3 and -13 and promoted cell proliferation associated with reduced alkaline phosphatase activity as well as enhanced phosphorylated expression of extracellular signal-regulated kinase (ERK)1/2, p38 MAPK, and stress-activated protein kinases/c-jun N-terminal kinases (SAPK/JNK) in ROS17/2.8 cells. However, Ang II had no effect on the expression of MMP-2, -9, -14, urokinase-type PA, tissue-type PA, TIMP-1, -2, -3, and PAI-1 in cells. Losartan (AT1 receptor blocker) blocked Ang II-induced expression of MMP-3 and -13, whereas PD123319 (AT2 receptor blocker) did not completely block these responses. Losartan also blocked the Ang II-induced phosphorylation of ERK1/2, p38 MAPK, and SAPK/JNK. MAPK kinase 1/2 inhibitor PD98059 and JNK inhibitor SP600125 suppressed Ang II-induced expression of MMP-3 and -13. These results suggested that Ang II stimulated the degradation process that occurs during ECM turnover in osteoid by increasing the production of MMP-3 and -13 through MAPK signaling pathways via the AT1 receptor in osteoblasts. Furthermore, our findings suggest that Ang II does not influence the plasminogen/plasmin pathway in osteoblasts.
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PMID:Angiotensin II induces the production of MMP-3 and MMP-13 through the MAPK signaling pathways via the AT(1) receptor in osteoblasts. 2327 13