Cellular FADD-like IL-1β-converting enzyme-inhibitory protein attenuates myocardial ischemia/reperfusion injury via suppressing apoptosis and autophagy simultaneously.

BACKGROUND AND AIMS: Myocardial ischemia/reperfusion injury (MI/RI) is a result of coronary revascularization, and often increases cell apoptosis and autophagy. Downregulated cellular FADD-like-IL-1β-converting enzyme-inhibitory protein (cFLIP) was associated with development of several myocardial diseases, whether overexpression of cFLIP can attenuate MI/RI remains unclear. This study aimed to determine the effects of cFLIP on apoptosis and autophagy in MI/RI.

METHODS AND RESULTS: Ischemia/reperfusion (I/R) rat model and hypoxia/reoxygenation (H/R) cardiomyocytes model were established. Both I/R injury and H/R injury down-regulated expression of two cFLIP isoforms (cFLIPL and cFLIPS), and instigated apoptosis and autophagy simultaneously. Overexpression of cFLIPL and/or cFLIPS led to a significant increase in cardiomyocytes viability in vitro, and also reduced the myocardial infarct volume in vivo, these changes were associated with suppressed apoptosis and autophagy. Mechanistically, overexpression of cFLIP significantly downregulated pro-apoptotic molecules (Caspase-3, -8, -9), and pro-autophagic molecules (Beclin-1 and LC3-II). Moreover, cFLIP significantly suppressed activity of NF-κB pathway to upregulate the expression of Bcl-2, which is the molecular of interplay of apoptosis and autophagy.

CONCLUSION: Overexpression of cFLIP significantly attenuated MI/RI both in vivo and vitro via suppression of apoptosis and lethal autophagy. cFLIP can suppress activity of NF-κB pathway, and further upregulated expression of Bcl-2.