Transcription Factor SP1 Drives Myocardial Ischemia/reperfusion Injury By Transcription Activation-mediated GADD45G Upregulation.

Myocardial ischemia-reperfusion injury (MIRI) is an unresolved clinically fatal complication in the management of acute myocardial infarction (AMI). Growth arrest and DNA damage-inducible gene 45 Gamma (GADD45G) plays a vital role in the regulation of MIRI. However, the underlying mechanisms remain unclear. GADD45G and SP1 expression were upregulated in hypoxia/reoxygenation (H/R)-treated H9C2 cells. H/R treatment repressed H9C2 cell viability, and induced apoptosis, oxidative stress, and inflammatory response. Moreover, GADD45G deficiency could relieve H/R-triggered H9C2 cell injury. In mechanism, SP1 was a transcription factor of GADD45G and activated the transcription of GADD45G via binding to its promoter region. Besides, SP1 knockdown alleviated MI/R-induced pathological damage in the myocardial tissue of rats by regulating GADD45G. In conclusion, SP1 could promote H/R-induced cardiomyocyte injury and MI/R-caused rat myocardial tissue pathological injury by increasing GADD45G, providing a promising therapeutic target for MIRI treatment.