MFN2 and Hyperglycemia: To assess the involvement of Mfn2 in hyperglycemia-induced cardiomyocyte injury, we transfected the cardiomyocytes with siRNA against Mfn2. Then, we measured the contraction and relaxation functions of single cardiomyocytes using Fura-2-acetoxymethyl ester (Fura-2AM).