Mdivi‐1 Mitigates ROS and Mitophagy, Improves Healthy Mitochondrial Pool in Hyperglycemic Cardiomyocytes

Abstract

Cardiac function is contingent upon mitochondrial health and turn over. To test the hypothesis that Mdivi‐1 mitigates reactive oxygen species (ROS) and mitophagy, and improves healthy mitochondrial pool in hyperglycemic cardiomyocytes, we used four treatment groups of HL‐1 cardiomyocytes: low (LG‐5mM) and high (HG‐25mM) doses of D‐glucose, HG+Mdivi‐1, and HG+DMSO (di‐methyl sulfoxide). To evaluate ROS, mt‐ΔΨ, mitophagy and mitochondrial biogenesis, we determined the levels of DHE, MitoSox, JC1 (hypopolarized green vs hyperpolarized red color), Beclin1, LC3B, PGC‐1α, Mfn‐1, and ratio of mitochondrial to nuclear DNA in the four groups by qPCR, Western blotting and immunofluorescence. Our results revealed that DHE intensity, MitoSox intensity, Beclin1 and LC3B are up regulated by 3.54±0.08, 1.6±0.03, 1.4± 0.05 and 3.6±1.9 folds in HG but down regulated by 1.18±0.3, 1.1±0.03, 0.9±0.03 and 1.96±0.07 folds in HG+Mdivi‐1, respectively. The mt‐ΔΨ decreased in HG by 0.8± 0.06 folds but increased after treatment with Mdivi‐1 by 0.9±0.1 folds. The ratio of mitochondrial DNA (D‐loop, ND‐6) vs nuclear DNA (GAPDH, PGC‐1α) increased 1.01±0.08, 1.07±0.04 folds in HG. However, it was decreased by 0.95±0.02, 1.0±0.5 folds after treatment with Mdivi‐1. Further, Mdivi‐1 treatment decreased expression of PGC‐1α, Mfn‐1 by 0.92±0.7, 0.86±0.1 folds respectively. Based on these findings, we conclude that Mdivi‐1 mitigates glucose mediated induction of ROS, and depolarization of mitochondria, and restores healthy mitochondrial pool in cardiomyocytes.