IRF2 contributes to myocardial infarction via regulation of GSDMD induced pyroptosis

Abstract

Interferon regulatory factor (IR F) 2 is a transcription factor belonging to the IR F family, which is essential for gasdermin D (GSDMD)-induced pyroptosis. Decreasing myocardial cell pyroptosis confers protection against heart damage and cardiac dysfunction caused by myocardial infarction (MI). The aim of the present study was to investigate the involvement of IR F2 in MI and the underlying mechanism of IR F2 in pyroptosis. To mimic MI, ligation of the left anterior descending coronary artery was performed to establish an in vivo mouse model and rat cardiomyocytes H9c2 cells were cultured under hypoxic conditions to establish an in vitro model. Transthoracic echocardiography was used to assess cardiac function. Hematoxylin and eosin staining was used to observe histopathological changes in the myocardial tissue. Immunohistochemistry and western blotting were performed to detect IR F2 expression levels. TUNEL staining and flow cytometry were used to detect apoptosis in myocardial tissue and cells. Chromatin immunoprecipitation and dual luciferase reporter assay were used to verify the effect of IR F2 on GSDMD transcription. IR F2 was upregulated in MI mice. MI induced pyroptosis, as evidenced by increased GSDMD, N-terminal GSDMD (GSDMD-N), and cleaved (c-) caspase-1 levels. MI increased IL -1β and IL -18 levels. These alterations were alleviated by IR F2 silencing. Furthermore, in hypoxia-treated H9c2 cells, IRF2 silencing significantly decreased the elevated levels of IL -1β and IL -18 and pyroptosis-associated proteins, including GSDMD, GSDMD-N and c-caspase1. Moreover, in hypoxia-treated H9c2 cells, IR F2 directly bound to the GSDMD promoter to drive GSDMD transcription and promote pyroptosis and IR F2 expression may be regulated via the hypoxia inducible factor 1 signaling pathway. In conclusion, the present results demonstrated that IR F2 is a key regulator of MI by mediating pyroptosis, which triggers GSDMD activation.