DC2421 - Investigating Cardioprotective Effects of the Adiponectin Mimetic Peptide, ALY688, on High Glucose-Induced Cell Death in Cardiomyoblasts

Blinded Abstract: Diabetic cardiomyopathy is (DCM) is a common complication of diabetes that can lead to heart failure. In this study, we investigated mechanisms through which cell death occurs in cultured H9c2 cardiomyoblasts treated with high glucose (25 mM). We examined the cardioprotective effects of the adiponectin receptor agonist, ALY688, and the mechanisms through which the protective effects are exerted, namely attenuation of inflammation and induction of autophagy. Western blot to detect caspase-3 showed a significant increase in cleaved caspase-3 levels following 24-hour treatment under high glucose conditions compared to normal glucose, indicating activation of apoptosis in H9c2 cells. This effect was significantly attenuated with ALY688 pre-treatment for 18 hours, followed by 24-hour co-treatment with high glucose. We investigated induction of autophagy as a potential mechanism through which ALY688 is exerting its protective effects. Western blot of LC3-II and p62 showed inhibition of autophagic flux after 24 hours high glucose conditions whereas pre-treatment with ALY688 led to increased autophagic flux. Furthermore, activation of the NF-kappaB pathway was also investigated via quantitative polymerase chain reaction (qPCR) to examine gene expression of various pro-inflammatory cytokines. We found a significant increase in IL-6, IFN-beta, iNOS, and TNF in cells treated with high glucose, all of which were reduced with ALY688. This study provides insight into the ability of ALY688 to attenuate high glucose induced cell death by stimulating autophagy and attenuating inflammation.