Abstract
To investigate the role of death-associated protein kinase 1 (DAPK1) in cardiac ischemia reperfusion (I/R) in vivo, and to determine whether the process is regulated by nuclear factor E2-associated factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (keap1). Western blot analysis was used to analyze the expression level of DAPK1 at different time points. The hemodynamic parameters and apoptosis of cardiac I/R injury in vivo were observed using DAPK1 knockdown lentivirus. The oxidative stress of I/R in vivo was observed. Nrf2-IN-1 was applied to determine whether the role of DAPK was regulated by Nrf2/keap1. Results show that the DAPK1 expression increased to a peak after 12 h of I/R. Moreover, the level of DAPK1 expression decreased, as determined by Western blot, after DAPK1 knockdown lentivirus administration. In addition, the hemodynamic parameters of the DAPK1-shRNA group were improved. The apoptosis level (Bax, Bcl-2, cleaved caspase-3, and TUNEL staining) increased in the I/R group, and the DAPK1 knockdown lentivirus could reverse the injury. The oxidative stress indices (CK, cTn-1, CAT, LDH, GSH-PX, MDA, and SOD) also improved in the DAPK1-shRNA group. Finally, Nrf2-IN-1 inhibited tNrf2, nNrf2, and Bcl-2 expression and boosted keap1, Bax, and cleaved caspase-3 expression after DAPK1 lentivirus administration. These findings suggest that DAPK1 may regulate the oxidative stress in cardiac I/R, and Nrf2/keap1 may be the downstream target factor of DAPK1.