SerpinA3 Promotes Myocardial Infarction in Rat and Cell-based Models

This study aimed to examine the role and molecular mechanism of the nuclear factor κB (NFκB)/serine protease inhibitor A3 (SerpinA3) interaction in myocardial ischemia-reperfusion (IR) injury. First, a rat model for myocardial ischemia-reperfusion injury was established, using 2,3,5-triphenyltetrazolium chloride to measure the size of the myocardial infarction. Pathological variations in myocardial tissue were detected using hematoxylin-eosin staining. Flow cytometry and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining were used to measure cell death in the rat model. The SerpinA3 mRNA and protein expressions in the myocardium of IR-model rats were remarkably higher than those in the control group. Furthermore, the oxidative, inflammatory, and apoptotic activities of the myocardial tissue of SerpinA3-knockdown (KD) rats were significantly improved compared to those in the WT group. SerpinA3-KD also contributed to the recovery of cardiac function in IR-model rats. Additionally, silencing of SerpinA3 inhibited p65 phosphorylation in myocardial tissues and reduced H₂O₂-induced inflammation, oxidative stress, and apoptosis in myocardial cells. The expression of SerpinA3 increased in myocardial tissue after IR stimulation. Knockdown of SerpinA3 can deactivate NF-κB and reduce inflammation, oxidative stress, and apoptosis in vivo and in vitro, thereby lessening myocardial injury caused by IR. In conclusion, SerpinA3 promotes myocardial infarction in rat and cell-based models by activating NF-κB. However, the mechanism by which increased Serpina3 expression causes downstream NF-κB activation to mediate the proposed, pathological effects in myocardial IR injury remain untested and worthy of future investigations.