Identification of promoter activity and differential expression of transcripts encoding the murine stromelysin-1 gene in renal cells

Abstract

Stromelysin-1, matrix metalloproteinase-3 (MMP-3), is an important endopeptidase selectively expressed by somatic cells in organ tissues. The renal tubulointerstitium, for example, comprises tubular epithelium and interstitial fibroblasts forming the principal mass of the kidney. We observed that mRNA encoding stromelysin-1 is detectable in murine renal fibroblasts, but not in proximal tubular epithelium. Transcripts measured by RNase protection assay in renal fibroblasts increase following exposure to phorbol ester, and thereafter, activated stromelysin-1 protein can be detected in culture media by Western blotting. A 6.4 Kb genomic clone containing the putative stromelysin-1 promoter was isolated and a relevant 2.1 Kb PstI restriction fragment including 2.1 Kb of the immediate 5'-flanking region was sequenced on both strands. Two transcriptional start sites were identified by primer extension; the major start site corresponded to a previously established position in the rat promoter, and a second undescribed minor transcriptional start site was located 16 bp upstream of the primary site. A HiNF-A chromatin-activating element at -106 bp was found in the early promoter region of pR336 and an active AP-1 site at -72 bp with an Ets/PEA-3 motif at -203 bp was suggested by transient transfection of luciferase minigenes into renal fibroblasts responsive to phorbol ester. This Ets element was identical to a site in the early promoter of the fibroblast-specific gene FSP1. A baseline enhancement in activity of pR336 in fibroblasts was further observed with the addition of 5' flanking sequence out to -1980 bp. This additional region of flanking sequence contains two modular regions: one of multiple PEA-3 elements between -684 bp and -1955 bp and a second region between -1929 bp and -1980 bps containing a second AP-1 site at -1929 bp, a MBF-1/ MEP-1 metal binding site, and a PPAR peroxisome proliferator element at -1950 bp. Our findings implicate a gene structure with expected activity in a mesenchymal phenotype. The PKC-dependent regulation of the stromelysin-1 gene supports the notion that it may be modulated during inflammation or tissue remodeling.

Localization and Expression of Messenger RNAs for the Peroxisome Proliferator-Activated Receptors in Ovarian Tissue from Naturally Cycling and Pseudopregnant Rats1

“…For example, PPARs have been shown to regulate the activity and expression of two proteases, gelatinase B [7,[9][10][11] and urokinase plasminogen activator (uPA) [5]. Another protease, stromelysin, has a PPRE in its promoter region [6], suggesting that expression of this protease is also regulated by PPARs. These proteases have been identified in ovarian and/or luteal tissue from various species (for review, see [12,13]), indicating that PPARs could regulate protease activity and influence luteal formation and/or regression.…”

“…The PPARs are capable of influencing gene transcription by heterodimerizing with the 9-cis, retinoic acid receptor (RXR) and binding to PPAR response elements (PPREs) in the promoter region of target genes. Some of the genes that have been shown to be regulated by the PPARs are involved in tissue remodeling, angiogenesis, and prostaglandin production [5][6][7][8].…”

Peroxisome Proliferator-activated Receptor-γ Down-regulates Chondrocyte Matrix Metalloproteinase-1 via a Novel Composite Element

“…We searched for the presence of a DR1-PPRE overlapping an AP1 element in the promoter of MMP3, MMP9, and MMP13. An AP-1 site at position Ϫ1929 and a PPRE at position Ϫ1950 have been recently identified in the murine MMP3 (47). Computer analysis of the human MMP3 (GenBank TM accession number AF405705) allowed us to identify a degenerated DR1-PPRE overlapping an AP1 element at position Ϫ73 to Ϫ63 (CAAGGATGAGTCA).…”

Peroxisome proliferator-activated receptors (PPARs) and ovarian function – implications for regulating steroidogenesis, differentiation, and tissue remodeling

“…Activation of PPARα and PPARγ decreases MMP-9 expression and its activity [88-91]. The promoters for MMP-3 [92] and MMP-9 [93] contain a PPRE, indicating that transcription of these proteases is likely directly regulated by PPARs. PPARγ activation can also reduce expression of MMP-13 and MMP-1 by interfering with AP-1 activation [94-96].…”