Mitochondria-targeted antioxidant peptide SS31 attenuates high glucose-induced injury on human retinal endothelial cells

► ROS and mitochondrial dysfunction have been described as the central part of the pathogenesis of diabetic retinopathy. ► SS31 is a novel class of mitochondria-targeted antioxidant peptide, and it can scavenge H2O2 and ONOO- and inhibit lipid peroxidation. ► In our study, we provided the first evidence that SS31 could attenuate the high glucose-induced injuries on HRECs by reducing ROS production, stabilize mitochondrial potential and decrease the release of cytochrome c from mitochondria to cytoplasm. ► In addition, SS31 also could decrease the expression of caspase-3 and increase the expression of Trx-2. ► Our study suggests that SS31 has excellent potential as a new therapeutic for the treatment of diabetic retinopathy and other oxidative stress related diseases.