Identification of the interleukin-6/oncostation M response element in the rat tissue inhibitor of metalloproteinases-1 (TIMP-1)Promoter

Abstract

The rat tissue inhibitor of metalloproteinase 1 (TIMP-1) gene is expressed in rat hepatocytes, and this expression is up-regulated by interleukin 6 (IL-6). We report here the cloning of the 5' flanking region of the rat TIMP-1 gene and identification of an IL-6/oncostatin M (OSM) response element at -64 to -36 which functions in hepatic cells. Within this element we have identified two functional binding sites for transcription factors AP-1 (activatory protein-1) and STAT (signal transducer and activator of transcription). IL-6/OSM stimulation induces binding of a protein, identified as STAT3, to the IL-6/OSM response element, while binding of the AP-1 protein was constitutive. Binding sites for both AP-1 and STAT3 are necessary for full responsiveness of the TIMP-1 promoter to IL-6/OSM, as shown by deletion and mutation analysis. Furthermore, the entire IL-6/OSM response element conferred responsiveness onto a heterologous promoter, whereas this has not been observed when AP-1 and STAT elements were separately tested.

Control of the tissue inhibitor of metalloproteinases-1 promoter in culture-activated rat hepatic stellate cells: Regulation by activator protein-1 DNA binding proteins

“…Additional EMSA studies on several independently prepared time course samples confirmed this transient induction and showed no re-induction of LMAP-1 for up to 13 days of continual culture. As previous studies have suggested that c-Fos and c-Jun are important regulators of TIMP-1 promoter activity, 26,28,29 we examined nuclear extracts for expression of these AP-1 family proteins by Western blotting (Fig. 3B).…”

“…The basic structure of the human, rat, and mouse TIMP-1 genes and their promoters have been previously described with several regulatory features of the promoter being highly conserved. [23][24][25][26][27][28][29][30] The TIMP-1 promoter utilizes multiple transcription start sites and lacks a consensus TATA box. Evolutionary conserved sequences in the 5Ј untranscribed DNA region flanking the transcription initiation site confer transcriptional regulation in response to viruses, serum, phorbol esters, transforming growth factor-␤ and interleukin-6/oncostatin M. [23][24][25][26][27][28][29][30] Responsiveness to this diverse range of epigenetic factors appears to be dependent on an almost perfectly conserved (1 bp mismatch between human, mouse, and rat genes) 22-bp Serum Response Element (SRE) that contains binding sites for the AP-1, STAT-3, and Pea3 transcription factors.…”

“…[23][24][25][26][27][28][29][30] The TIMP-1 promoter utilizes multiple transcription start sites and lacks a consensus TATA box. Evolutionary conserved sequences in the 5Ј untranscribed DNA region flanking the transcription initiation site confer transcriptional regulation in response to viruses, serum, phorbol esters, transforming growth factor-␤ and interleukin-6/oncostatin M. [23][24][25][26][27][28][29][30] Responsiveness to this diverse range of epigenetic factors appears to be dependent on an almost perfectly conserved (1 bp mismatch between human, mouse, and rat genes) 22-bp Serum Response Element (SRE) that contains binding sites for the AP-1, STAT-3, and Pea3 transcription factors. [23][24][25][26][27][28][29][30] Of these binding sites, the AP-1 sequence seems to be crucial for the ability of the TIMP-1 promoter to respond to extracellular stimuli.…”

“…Evolutionary conserved sequences in the 5Ј untranscribed DNA region flanking the transcription initiation site confer transcriptional regulation in response to viruses, serum, phorbol esters, transforming growth factor-␤ and interleukin-6/oncostatin M. [23][24][25][26][27][28][29][30] Responsiveness to this diverse range of epigenetic factors appears to be dependent on an almost perfectly conserved (1 bp mismatch between human, mouse, and rat genes) 22-bp Serum Response Element (SRE) that contains binding sites for the AP-1, STAT-3, and Pea3 transcription factors. [23][24][25][26][27][28][29][30] Of these binding sites, the AP-1 sequence seems to be crucial for the ability of the TIMP-1 promoter to respond to extracellular stimuli. [23][24][25][26][27][28][29][30] We show in the present study that culture activation of HSCs is associated with a dramatic induction of TIMP-1 promoter activity, map the minimal region of the promoter required for this response, and describe regulatory DNA sequences that may play a key role in regulation of TIMP-1 promoter activity.…”

“…[23][24][25][26][27][28][29][30] Of these binding sites, the AP-1 sequence seems to be crucial for the ability of the TIMP-1 promoter to respond to extracellular stimuli. [23][24][25][26][27][28][29][30] We show in the present study that culture activation of HSCs is associated with a dramatic induction of TIMP-1 promoter activity, map the minimal region of the promoter required for this response, and describe regulatory DNA sequences that may play a key role in regulation of TIMP-1 promoter activity. As an AP-1 binding site appears to be a critical regulatory element in the TIMP-1 promoter, we also examine the regulation of AP-1 proteins during the culture activation of rat HSCs.…”