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

Purpose

To investigate the effect of mitochondria-targeted antioxidant peptide SS31 on prevention of high glucose-induced injury on human retinal endothelial cells (HRECs).

Methods

Cultured P3–P5 HRECs were divided into three groups: 5 mM glucose group, 30 mM glucose group and 30 mM glucose co-treated with 100 nM SS31 group. 24 and 48 h after treatment, Annexin V-FITC/PI staining was used to evaluate the survival of HRECs. Overproduction of ROS was assessed by MitoSOX staining under confocal microscope. Change of mitochondrial potential (ΔΨ_m) of HRECs was measured by flow cytometry after JC-1 fluorescent probe staining. Release of cytochrome c was assessed by confocal microscopy and western blot. Expression of caspase-3 and thioredoxin-2 (Trx-2) were measured by western blot and real-time PCR.

Results

Compared to the high glucose group, co-treatment with 100 nM SS31 significantly protected HRECs from high glucose-induced injury, reduced the production of ROS in mitochondria, stabilized ΔΨ_m, decreased the release of cytochrome c from mitochondria to cytoplasm, decreased the expression of caspase-3 and increased the expression of Trx-2 in high glucose-treated HRECs.

Conclusions

SS31 attenuates the high glucose-induced injuries on HRECs by stabilizing ΔΨ_m, decreasing ROS production, preventing the release of cytochrome c from mitochondria, decreasing the expression of caspase-3 and increasing the expression of Trx-2. Our study suggests that SS31 may be as a potential new treatment for diabetic retinopathy and other oxidative stress-related diseases.