Fig. 6

A simplified model depicting the mechanisms of PIAS1 involved in myocardial IRI. a PIAS1 expression is down-regulated in cardiomyocytes during ischemia/reperfusion (I/R), resulting in decreased SUMOylation of PPARγ, which directly inhibits NF-κB pathway. The activation of NF-κB can induce transcription of inflammatory cytokines and further lead to apoptosis and cell death. b Knockdown of PIAS1 by si-RNA can aggregate the inflammation and apoptosis of cardiomyocyte through PPARγ SUMOylation mediated NF-κB pathway during I/R. c Overexpression of PIAS1 alleviates injury of myocardial I/R by increasing SUMOylation of PPARγ and down-regulation of NF-κB pathway