Mitochondria-Targeted Antioxidant Peptide SS31 Protects Cultured Human Lens Epithelial Cells against Oxidative Stress.

PURPOSE: To investigate the effects of the mitochondria-targeted peptide, SS31, on cultured human lens epithelial cells (HLECs) under conditions of oxidative stress.

METHODS: Optimal concentrations of SS31 were determined by MTT assay. HLEB-3 cells were first treated with SS31 for 2 h and then with 500 µM t-BHP for 6 h. Cell apoptosis was revealed by Annexin V/PI staining. Morphological changes in nuclei were observed by fluorescence microscopy after Hoechest 33258 fluorescent staining. Reactive oxygen species (ROS) were measured by MitoSOX staining. Changes in mitochondrial membrane potential (ΔΨm) were detected using the JC-1 fluorescent dye. Activation of p38 and c-Jun N-terminal kinases (JNKs) were quantified by Western Blot analysis.

RESULTS: SS31 protected HLEB-3 cells against t-BHP-induced cell apoptosis, reduced ROS, maintained ΔΨms, and inhibited activation of JNK and p38 pathways.

CONCLUSIONS: SS31 was able to protect HLEB-3 cells against oxidative damage and, thus, represents a potential new treatment modality for preventing the formation of cataracts and other age-related disorders.