MiR-302a Regenerates Human Corneal Endothelial Cells against IFN-gamma-Induced Cell Death

Damage to human corneal endothelial cells (hCECs) leads to bullous keratopathy because these cells cannot be regenerated in vivo. In this study, we investigated the protective role of microRNA (miR)-302a against interferon-gamma (IFN-gamma)-induced senescence and cell death of hCECs. Cultured hCECs were transfected with miR-302a and treated with IFN-gamma (20 ng/mL) to evaluate the protective effect of miR-302a on IFN-gamma-induced cell death. Senescence was evaluated by the senescence-associated beta-galactosidase (SA-beta-gal) assay, and the secretion of senescence-associated secretory phenotype (SASP) factors was analyzed. Mitochondrial function and endoplasmic reticulum (ER) stress were assessed. We revealed that miR-302a enhanced the cell viability and proliferation of hCECs and that IFN-gamma increased the cell size, the number of SA-beta-gal-positive cells, and SASP factors, and arrested the cell cycle, which was eliminated by miR-302a. miR-302a ameliorated mitochondrial oxidative stress and ER stress levels which were induced by IFN-gamma. IFN-gamma decreased the mitochondrial membrane potential and promoted autophagy, which was eliminated by miR-302a. The in vivo study showed that regeneration of rat CECs was promoted in the miR-302a group by inhibiting IFN-gamma and enhancing mitochondrial function. In conclusion, miR-302a eliminated IFN-gamma-induced senescence and cellular damage by regulating the oxidative and ER stress, and promoting the proliferation of CECs. Therefore, miR-302a may be a therapeutic option to protect hCECs against IFN-gamma-induced stress.