AP-1 mediated transcriptional repression of matrix metalloproteinase-9 by recruitment of histone deacetylase 1 in response to interferon ?.

ABSTRACT: Matrix metalloproteinase-9 (MMP-9) is a 92 kDa zinc-dependant endopeptidase that degrades components of the extracellular matrix. Increased expression of MMP-9 is implicated in many pathological conditions including metastatic cancer, multiple sclerosis, and atherosclerosis. Although it has been widely noted that interferon-? (IFN?) downregulates both the basal and phorbol 12-myristate 13-acetate (PMA)-induced MMP-9 expression at the transcriptional level, the molecular mechanism of this repression is poorly understood. In the present study we identify a novel mechanism for repression of MMP-9 transcription by IFN? in HT1080 fibrosarcoma cells. Using reporter assays with promoter deletion constructs we show that IFN?'s inhibitory effects require a region of the promoter between -154 and -72, which contains an AP-1 binding site. Chromatin immunoprecipitation (ChIP) studies indicate that IFN? increases histone deacetylase (HDAC)-1 recruitment to the MMP-9 promoter and reduces histone H3 acetylation, in addition to reduced NF-?B recruitment. ChIP analysis shows that IFN? induced HDAC1 recruitment to the MMP-9 promoter and IFN? mediated transcriptional repression is lost when the AP-1 binding site is inactivated by a point mutation. Altogether, our results establish that the repression of MMP-9 transcription in response to IFN? occurs by the recruitment of HDAC1 via the proximal AP-1 binding site.

SUBMITTER: Mittelstadt ML 

PROVIDER: S-EPMC3412826 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature