Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.24 (mitogen-activated protein kinase)
 95,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Smooth muscle cell (SMC) migration and proliferation are important events in the formation of intimal lesions associated with atherosclerosis and restenosis following balloon angioplasty. The extracellular matrix has important functions in modulating SMC structure and function, but less is known about the role of the matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors. The present study investigates the effects of the synthetic MMP inhibitor batimastat (BB94) on vascular SMCs. As experimental model, rat aortic smooth muscle cells in primary and secondary cultures were employed. Electron microscopy was used to investigate the effects of BB94 on the overall phenotypic properties of the cells. Induction of DNA synthesis and migration was studied by thymidine autoradiography and counting of cells moving into an injured zone. Gelatin zymography was used for the detection of BB94-mediated inhibition of injury-induced MMP activity. Phosphorylation of the mitogen-activated protein kinases ERK1/ERK2, two potential mediators of the injury-induced activation of the cells, was measured by Western blotting. The results show that BB94 restrained the phenotypic modulation of vascular SMCs in primary cultures and suppressed injury-induced DNA synthesis and migration. Moreover, the upregulation of ERK1/ERK2 phosphorylation in injured secondary cultures and in cells treated with bFGF was markedly reduced by BB94, whereas TIMP-2 lacked a clear effect. Our data suggest that BB94 inhibits injury-induced activation of vascular SMCs by acting on MMPs as well as other targets.
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PMID:The synthetic metalloproteinase inhibitor batimastat suppresses injury-induced phosphorylation of MAP kinase ERK1/ERK2 and phenotypic modification of arterial smooth muscle cells in vitro. 1102 97

We previously showed that enhanced expression of MMP-9, an endopeptidase that digests basement-membrane type IV collagen, is related to tumor progression in vitro and in vivo; antisense-MMP-9 stably transfected clones were less invasive than untransfected parental cells and did not form tumors in nude mice. In this study, we examined the role of ERK-1 in the regulation of MMP-9 production and the invasive behavior of the human glioblastoma cell line SNB19, in which ERK1 is constitutively activated. SNB19 cells were stably transfected with mt-ERK, a vector encoding ERK-1 cDNA in which the conserved lysine at codon 71 was changed to arginine, thus impairing the catalytic efficiency of this enzyme. Gelatin zymography showed reduced levels of MMP-9 in the mt-ERK-transfected cell lines relative to those in vector-transfected and parental control cells. Reductions in MMP-9 protein mRNA levels were also detected in the mt-ERK-transfected cells by Western and Northern blotting. The mt-ERK-transfected cells were much less invasive than parental or vector control cells in a Matrigel invasion assay and in a spheroid coculture assay. Thus an ERK-dependent signaling pathway seems to regulate MMP-9 mediated glioma invasion in SNB19 cells; interfering with this pathway could be developed into a therapeutic approach, which aims at a reduction of cancer cell invasion.
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PMID:Downregulation of MMP-9 in ERK-mutated stable transfectants inhibits glioma invasion in vitro. 1216 59

Fuzhengfangaitang (FZFAT) is used to inhibit recurrence and metastasis of cancer in the clinic. By applying an in vitro invasion assay model, we examined the antimetastatic effect of FZFAT. In the 3H-thymidine incorporation assay, FZFAT-treated groups showed a decreased DNA synthesis rate compared with the control group (F-value 87.42981, P-value 2.02E-08, F0.05(3,12) 3.4903). Gelatin zymogram assay showed that FZFAT decreased the gelatinolytic activity of matrix metalloproteinases-9 (MMP-9) from human fibrosarcoma cell line (HT-1080), at concentrations of 200 and 400 microg/ml. In the MMPs dot blotting assay, FZFAT inhibited the expression of MMP-1 at concentration of 100 microg/ml, and MMP-9 at concentrations of 200 and 400 microg/ml. Western blots for AP-1 and its signal mediators Erk and JNK showed that expression of Fos and JNK were decreased by the addition of FZFAT at 300 microg/ml, whereas Erk was not. Therefore it was evident that FZFAT regulated the expression of MMP-9 through its transcription factor AP-1 and the signal mediator JNK. We examined whether FZFAT inhibited the invasion of HT-1080 cells through matrigel precoated transwell chambers. The results showed that FZFAT effectively inhibited the invasion of HT-1080 cells as compared with the control phorbol 12-myristate-13-acetate (+PMA) groups (t-value 5.871584, P-value 0.013901, t0.05(2) 2.919987). From our research, part of the mechanism underlying the antimetastatic effect of FZFAT has been elucidated in vitro.
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PMID:Anti-metastatic effects of fuzhengfangaitang on human fibrosarcoma cells HT1080. 1285 62

Recent evidences have demonstrated an important role for glomerular visceral epithelial cell (podocyte) in the development and progression of diabetic nephropathy. We investigated the high-glucose (HG)-triggered signaling pathway and its role in matrix metalloproteinase (MMP) production in murine podocytes. The activity of 92-kDa (MMP-9) gelatinase, but not of 72 kDa (MMP-2), in an HG medium significantly increased during incubation of 2 to 3 days and decreased during incubation of more than 5 days revealed by Gelatin zymography. Opposite to the increases in MMP-9 activity, HG medium produced significant decreases in the protein levels of alpha5(IV) collagen. Changes in MMP-9 activity were associated with the same pattern as MMP-9 mRNA levels in podocytes exposed to HG media. HG medium rapidly activated ERK1/2 MAPK in podocytes. Moreover, ERK1/2 activation was required for HG-induced enhancement of MMP-9 activity and a decrease in the level of alpha5(IV) collagen. HG incubation rapidly induced an increase in the nuclear accumulation of Ets-1 protein. Blocking the ERK pathway suppressed HG-induced expression and nuclear accumulation of transcriptional factor Ets-1, and MMP-9 mRNA expression. We suggest that short- or long-term exposure to HG concentrations increases or decreases MMP-9 production and alpha5(IV) collagen expression in podocytes, this may contribute to the GBM abnormality caused by an imbalance in extracellular matrix (ECM) synthesis and degradation, and may play a critical role in the pathogenesis of proteinuria in diabetic nephropathy.
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PMID:High ambient glucose levels modulates the production of MMP-9 and alpha5(IV) collagen by cultured podocytes. 1654 22

The net balance of matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases (TIMP) system has been known to be a key factor in tumor cell invasion. In the present study, we investigated the molecular mechanisms of anti-invasive and antimigrative activity of transforming growth factor (TGF)-beta1 on HT1080 human fibrosarcoma cells. In in vitro Matrigel invasion and Transwell migration assays, TGF-beta1 dose-dependently inhibited the invasion and migration of HT1080 cells, respectively. Gelatin zymography, Western blot, and real-time PCR analysis showed that TGF-beta1 enhanced the expression and secretion of MMP-2, TIMP-1, and, to a lesser degree, MMP-9 but not membrane type 1-MMP and TIMP-2. The addition of recombinant TIMP-1 protein reduced the Matrigel invasion and Transwell migration of HT1080 cells, similar to TGF-beta1. Because augmentation of TIMP-1 might be the major factor for the anti-invasive and antimigrative activity of TGF-beta1, we investigated possible molecular mechanisms responsible for the expression of TIMP-1 induced by TGF-beta1. Treatment of HT1080 cells with TGF-beta1 rapidly phosphorylated three mitogen-activated protein kinases [MAPK; extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and c-Jun NH2-terminal kinase] and Akt. Among these kinases, the inhibition of only ERK1/2 pathway by PD98059, a specific inhibitor of MAPK/ERK kinase(MEK)-1, and transfection of dominant-negative MEK 1 effectively blocked the TIMP-1 induction by TGF-beta1. Mithramycin, a specific inhibitor of Sp1 transcription factor, but not curcumin, an inhibitor of activator protein-1, and transfection of Sp1 small interfering RNA significantly inhibited the TGF-beta1-induced expression of TIMP-1. In addition, electrophoretic mobility shift assay showed that TGF-beta1 up-regulated Sp1 DNA-binding activity, and PD98059 and mithramycin effectively inhibited these events. Finally, pretreatment of HT1080 cells with PD98059 and mithramycin, but not curcumin, restored the invasive activity of these cells. Taken together, these data suggest that TGF-beta1 modulates the net balance of the MMPs/TIMPs the systems in HT1080 cells for anti-invasion and antimigration by augmenting TIMP-1 through ERK1/2 pathway and Sp1 transcription factor.
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PMID:Transforming growth factor-beta1 induces tissue inhibitor of metalloproteinase-1 expression via activation of extracellular signal-regulated kinase and Sp1 in human fibrosarcoma cells. 1654 58

PCK3145 is a synthetic peptide corresponding to amino acids 31-45 of prostate secretory protein 94 which can reduce experimental skeletal metastases and prostate tumor growth. These anti-metastatic and anti-tumoral effects of PCK3145 are partially explained by the in-vivo and in-vitro decrease in matrix metalloproteinase (MMP)-9 extracellular levels through as yet unidentified molecular mechanisms of action. Gelatin zymography and immunoblots were used to monitor the levels of secreted MMP-9 from HT-1080 cells. Flow cytometry was used to monitor HT-1080 cell surface binding of FITC-labeled PCK3145 and biotin-labeled laminin. PCK3145-coated cell culture dishes were used to monitor cell adhesion. HT-1080 cell lysates were used for immunoblotting of HuR, extracellular signal-regulated protein kinase (ERK) and phospho-ERK. Total RNA was isolated and RT-PCR used to monitor HuR gene expression. We found that PCK3145 bound to the HT-1080 cell surface and that this binding rapidly triggered ERK phosphorylation that, ultimately, led to a reduction of secreted MMP-9. Laminin inhibited both cell surface binding and ERK phosphorylation by PCK3145. Overexpression of the 67-kDa laminin receptor led to an increased binding of the cells to PCK3145. HuR, a protein that can bind to and stabilize MMP-9 mRNA, was found to be downregulated by PCK3145. The mitogen-activated protein kinase/ERK (MEK) inhibitor PD98059 as well as native laminin and SIKVAV laminin-derived peptide prevented that downregulation. Our data suggest that PCK3145 rapidly triggers intracellular signaling through cell surface laminin receptors. This leads to decreased HuR expression and subsequent destabilization of MMP-9 transcripts. This is the first molecular evidence demonstrating the intracellular signaling and anti-metastatic mechanism of action of PCK3145 that leads to the inhibition of MMP-9 secretion.
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PMID:Inhibition of MMP-9 secretion by the anti-metastatic PSP94-derived peptide PCK3145 requires cell surface laminin receptor signaling. 1655 1

Matrix metalloproteinases (MMPs), a family of extracellular endopeptidases, are implicated in angiogenesis because of their ability to selectively degrade components of the extracellular matrix. Interleukin-1beta (IL-1beta), increased in the heart post-myocardial infarction (post-MI), plays a protective role in the pathophysiology of left ventricular (LV) remodeling following MI. Here we studied expression of various angiogenic genes affected by IL-1beta in cardiac microvascular endothelial cells (CMECs) and investigated the signaling pathways involved in the regulation of MMP-2. cDNA array analysis of 96 angiogenesis-related genes indicated that IL-1beta modulates the expression of numerous genes, notably increasing the expression of MMP-2, not MMP-9. RT-PCR and Western blot analyses confirmed increased expression of MMP-2 in response to IL-1beta. Gelatin in-gel zymography and Biotrak activity assay demonstrated that IL-1beta increases MMP-2 activity in the conditioned media. IL-1beta activated ERK1/2, JNKs, and protein kinase C (PKC), specifically PKCalpha/beta(1), and inhibition of these cascades partially inhibited IL-1beta-stimulated increases in MMP-2. Inhibition of PKCalpha/beta(1) failed to inhibit ERK1/2. However, concurrent inhibition of PKCalpha/beta(1) and ERK1/2 almost completely inhibited IL-1beta-mediated increases in MMP-2 expression. Inhibition of p38 kinase and nuclear factor-kappaB (NF-kappaB) had no effect. Pretreatment with superoxide dismutase (SOD) mimetic, MnTMPyP, increased MMP-2 protein levels, whereas pretreatment with SOD and catalase mimetic, EUK134, partially inhibited IL-1beta-stimulated increases in MMP-2 protein levels. Exogenous H(2)O(2) significantly increased MMP-2 protein levels, whereas superoxide generation by xanthine/xanthine oxidase had no effect. This in vitro study suggests that IL-1beta modulates expression and activity of MMP-2 in CMECs.
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PMID:Interleukin-1beta increases expression and activity of matrix metalloproteinase-2 in cardiac microvascular endothelial cells: role of PKCalpha/beta1 and MAPKs. 1698 94

We have previously reported that platelet-activating factor (PAF) is present in very high levels in the ovine fetal lung and circulation and that PAF serves as an important physiological vasoconstrictor of the pulmonary circulation in utero. However, it is not known whether PAF stimulates pulmonary vascular smooth muscle cell (SMC) proliferation. In this study, we used ovine fetal pulmonary venous SMCs as our model system to study the effects and mechanisms of action of PAF on SMC proliferation. We found that PAF induced SMC proliferation in a dose-dependent manner. PAF also stimulated activation of both ERK and p38 but not c-Jun NH(2) terminal kinase (JNK) mitogen-activated protein (MAP) kinase pathways. PAF (10 nM) induced phosphorylation of epidermal growth factor receptor (EGFR). Specific inhibition of EGFR by AG-1478 and by the expression of a dominant-negative EGFR mutant in SMCs attenuated PAF-stimulated cell proliferation. Inhibition of heparin-binding EGF-like growth factor (HB-EGF) release by CRM-197 and inhibition of matrix metalloproteinases (MMP) by GM-6001 abolished PAF-induced MAP kinase activation and cell proliferation. Increased alkaline phosphatase (AP) activity after PAF treatment in AP-HB-EGF fusion construct-transfected SMCs indicated that PAF induced the release of HB-EGF within 1 min. Gelatin zymography data showed that PAF stimulated MMP-2 activity and MMP-9 activity within 1 min. These results suggest that PAF promotes pulmonary vascular SMC proliferation via transactivation of EGFR through MMP activation and HB-EGF, resulting in p38 and ERK activation and that EGFR transactivation is essential for the mitogenic effect of PAF in pulmonary venous SMC.
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PMID:Platelet-activating factor induces ovine fetal pulmonary venous smooth muscle cell proliferation: role of epidermal growth factor receptor transactivation. 1732 18

The aim of this study was to explore whether cyclosporine A (CsA) can modulate expression of MMP-9 and MMP-2 and invasion of the first-trimester human trophoblast cells. The invasive ability of the trophoblast cells modulated by CsA was observed by Matrigel invasion assay. The effect of CsA on the transcription and translation of MMP-9 and MMP-2 was determined by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Gelatin Zymography. In-cell Western was used to detect the level of phospho-ERK1/2 of trophoblast cells treated with CsA. We found that CsA(1.0 micromol/L) could remarkably promote the invasive ability of the first-trimester human trophoblast cells; CsA(1.0 micromol/L) could also induce the expression of MMP-9 and MMP-2 at transcriptional and translational level; U0126,a MEK inhibitor,could obviously inhibit the enhanced invasion and expression of MMP-9 and MMP-2 of these cells induced by CsA; CsA (1.0 micromol/L) could activate the ERKl/2 in a time-dependent manner. These results above indicate that CsA can induce the expression of MMP-9 and MMP-2 through activating MAPK/ERK1/2, which contributes to the improved invasion of the first-trimester human trophoblast cells.
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PMID:[Modulation of cyclosporin a on the expression of MMP-9 AND MMP-2 of the first-trimester human trophoblast cells]. 1735 50

Cardiovascular diseases (CVDs) result from the sub-endothelial accumulation of inflammatory cells and smooth muscle cells (SMCs). Lycopene, a natural compound from tomato, has been suggested to play a role in CVD prevention. However, its action mechanism is still largely unknown. In this study, we examined the effect of lycopene on SMCs. We found that preincubation of PDGF-BB with lycopene resulted in a marked inhibition on PDGF-BB-induced PDGF receptor-beta (PDGFR-beta), PLCgamma, and ERK1/2 phosphorylation in rat A10 SMCs and primary cultured aortic SMCs. In striking contrast, lycopene did not influence EGF-induced ERK1/2 phosphorylation. Surprisingly, further analysis indicates that lycopene could directly bind PDGF-BB and inhibit PDGF-BB-SMC interaction, as determined by dot binding assay and Western blotting. In functional studies, lycopene inhibited PDGF-BB-induced SMC proliferation and migration toward gelatin and collagen at concentrations ranging from 2 to 10 microM. On the contrary, lycopene did not inhibit bFGF- and VEGF-induced endothelial cell migration. Gelatin zymography demonstrated that lycopene's effect on SMC migration was not due to the inhibition of matrix metalloproteinases (MMPs). Taken together, our results provide the first evidence showing that lycopene inhibits PDGF-BB-induced signaling, proliferation and migration in rat A10 and aortic SMCs. One of the action mechanisms is that lycopene is capable of binding PDGF-BB and inhibiting its interaction with SMC, which is quite different from those previously developed PDGFR-beta antagonists. The results presented here may help us to better understand the beneficial effects of lycopene in CVD prevention.
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PMID:Lycopene binds PDGF-BB and inhibits PDGF-BB-induced intracellular signaling transduction pathway in rat smooth muscle cells. 1744 16


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