Intronic Regulation of Matrix Metalloproteinase-2 Revealed by in vivo Transcriptional Analysis in Ischemia

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 102; no. 45; pp. 16345 - 16350
• Main Authors: Jackie G. Lee, Sia Dahi, Rajeev Mahimkar, Nathaniel L. Tulloch, Maria A. Alfonso-Jaume, Lovett, David H., Rajabrata Sarkar
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 08.11.2005; National Acad Sciences
• Subjects: Animals; Antibodies; Biological Sciences; Blood flow; Blood vessels; Chromatin; Chromatin immunoprecipitation; Enhancer Elements, Genetic; Enzymes; Gene expression; Genes; Hindlimb - blood supply; Introns; Ischemia; Ischemia - enzymology; Matrix Metalloproteinase 2 - genetics; Medical research; Messenger RNA; Mice; Mice, Inbred C57BL; Muscle, Skeletal - enzymology; NFATC Transcription Factors - metabolism; Promoter Regions, Genetic; Proteins; Rodents; Transcription Factor AP-1 - metabolism; Transcription factors; Transcription, Genetic; Transcriptional regulatory elements; Tumor Suppressor Protein p53 - metabolism
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0508085102

Matrix metalloproteinase-2 (MMP-2) plays an essential role in angiogenesis and arteriogenesis, two processes critical to restoration of tissue perfusion after ischemia. MMP-2 expression is increased in tissue ischemia, but the responsible mechanisms remain unknown. We studied the transcriptional activation of the MMP-2 gene in a model of hindlimb ischemia by using various MMP-2-lacZ reporter mice and chromatin immunoprecipitation. MMP-2 activity and mRNA were increased after hindlimb ischemia. Mice with targeted deletion of MMP-2 had impaired restoration of perfusion and a high incidence of limb gangrene, indicating that MMP-2 plays a critical role in ischemia-induced revascularization. Ischemia induced the expression and binding of c-Fos, c-Jun, JunB, FosB, and Fra2 to a noncanonical activating protein-1 (AP-1) site present in the MMP-2 promoter and decreased binding of the transcriptional repressor JunD. Ischemia also activated the expression and binding of p53 to an adjacent enhancer site (RE-1) and increased expression and binding of nuclear factor of activated T-cells-c2 to consensus sequences within the first intron. Deletion of either the 5' AP-1/ RE-1 region of the promoter or substitution of the first intron abolished ischemia-induced MMP-2 transcription in vivo. Thus, AP-1 transcription factors and intronic activation by nuclear factor of activated T-cells-c2 act in concert to drive ischemia-induced MMP-2 transcription. These findings define a critical role for MMP-2 in ischemia-induced revascularization and identify both previously uncharacterized regulatory elements within the MMP-2 gene and the cognate transcription factors required for MMP-2 activation in vivo after tissue ischemia.