Transcription Factor Ets-1 Regulates Gelatinase A Gene Expression in Mesangial Cells

Abstract

Abstract. Ets transcription factors are involved in cell growth and angiogenesis. Ets-1 targets include members of the matrix metalloproteinase superfamily. In inflammatory glomerular diseases, the patterns and regulation of Ets expression have not been fully characterized. In the present study, nuclear binding activities to the consensus Ets-1/PEA3 motif were detected in mesangial cells (MC), and the Ets-1 protein was positively identified by Western blotting, reverse transcription PCR (RT-PCR), and DNA-binding studies. The 5' flanking regions of the human and rat gelatinase A genes contain clusters of potential Ets-1 binding motifs, one of which is evolutionarily conserved. Using a series of 5' deletion reporter constructs of the rat gelatinase A gene and an Ets-1 expression plasmid, a concentration-dependent threefold trans-activation of gene expression mapped to the conserved Ets-1 binding motif at Ϫ1004/Ϫ1053 bps, designated responsive element-2 (RE-2). The RE-2 was operative within the context of the homologous gelatinase A promoter but not with a heterologous simian virus 40 promoter. Specific Ets-1 binding to this sequence was demonstrated by DNA-binding studies. Transient expression of an Ets-1 expression plasmid increased gelatinase A protein expression. Our findings identify an additional matrix metalloproteinase family member, gelatinase A, as an Ets-1 responsive gene in MC that may play a role in the high level expression of this enzyme in inflammatory glomerular diseases.Mesangial cell (MC) proliferation, increased matrix turnover, and accumulation of interstitial collagens are common findings in most forms of progressive glomerular diseases (1). These changes generally continue even after removal of the initial causative event, progressively resulting in destruction of the glomerular architecture with the final outcome of glomerular scarring (1). Recent findings have elucidated a pivotal role for the "activated MC" phenotype (2). In contrast to the quiescent MC found within normal glomeruli, activated MC predominantly secrete interstitial type I and III collagens. Concurrently, high-level expression of matrix metalloproteinase-2 (MMP-2, 72-kD type IV collagenase, gelatinase A) is found (3,4). Gelatinase A belongs to the matrix metalloproteinase gene superfamily, all of which are secreted as latent proenzymes with subsequent activation by proteolysis in the extracellular space. The enzymatic activity of the MMP is dependent on the presence of zinc and divalent cations (5), and these enzymes exhibit broad substrate specificity (6). In addition to the role of gelatinase A in glomerular extracellular matrix turnover, the enzyme has a direct influence on the MC phenotype. Turck et al. (7) have shown that targeted deletion of gelatinase A in MC results in an exit from the cell cycle and development of a phenotype resembling quiescent MC in vivo. Addition of exogenous gelatinase A, but not gelatinase B, promoted MC proliferation with reacquisition of the prosclerotic phenotype (7). Concordant gelatinas...

Distinct gene expression profiles in norepinephrine- and epinephrine-producing hereditary and sporadic pheochromocytomas: activation of hypoxia-driven angiogenic pathways in von Hippel–Lindau syndrome

“…Up-regulation in VHL tumors of matrix metalloproteinase 2, a proteinase active in dissolving basement membranes during extracellular matrix reorganization, is consistent with the known induction of this gene by both VEGF and Ets-1 (Lamoreaux et al 1998, Reisdorff et al 2002. Similarly, increased expression in VHL tumors of the gene for the tissue inhibitor of the metalloproteinase 1 (TIMP1) is consistent with the associated role of this factor in extracellular matrix remodeling and induction of the gene by CYR61 (Chen et al 2001).…”

Prostaglandin E2 Enhances Pancreatic Cancer Invasiveness through an Ets-1-Dependent Induction of Matrix Metalloproteinase-2

“…Ets-1 is a known transcriptional regulator of MMP-2 expression (15,22), which binds to the region spanning Ϫ1255 to Ϫ1248 of the (18). Because of our observation that PGE 2 upregulates MMP-2 promoter activity, we sought to determine whether PGE 2 up-regulates Ets-1 binding activity.…”

“…We hypothesized that Ets-1 might play a role in PGE 2 -mediated MMP-2 induction. Ets-1 has been reported to be overexpressed in variety of malignancies, including pancreatic cancers (14), and to regulate the transcription of many MMPs, including MMP-2 (15,22,36,37). A recently reported study localized an Ets-1 binding site to the MMP-2 promoter (18).…”

Ets1 blocks terminal differentiation of keratinocytes and induces expression of matrix metalloproteases and innate immune mediators

“…However, in a large fraction of SCC tumors, Ets1 is highly expressed within the malignant keratinocytes, and its levels directly correlate with the invasive and metastatic potential of the tumor (Bai et al, 2009;Endo et al, 2006;Keehn et al, 2004;Pande et al, 1999;Saeki et al, 2000;Vairaktaris et al, 2007). Tumors that express high levels of Ets1 typically also express high levels of several matrix metalloprotease (Mmp) genes (Dittmer, 2003;Hahne et al, 2008;Lincoln and Bove, 2005) and Ets1 has been shown to directly regulate expression of multiple Mmp genes (Baillat et al, 2006;Nagarajan et al, 2009;Ozaki et al, 2000;Reisdorff et al, 2002;Wei et al, 2009;Westermarck et al, 1997). Yet, it has been unclear whether the sole oncogenic role of Ets1 is upregulation of Mmp expression or whether this protein also promotes squamous cell carcinoma development by affecting other pathways.…”