Mitochondria-Targeted Antioxidant (MitoQ) and Nontargeted Antioxidant (Idebenone) Mitigate Mitochondrial Dysfunction in Corneal Endothelial Cells.

PURPOSE: To investigate the effectiveness of mitochondrial-targeted antioxidant mitoquinone (MitoQ) and nontargeted antioxidant idebenone (Idb) in alleviating mitochondrial dysfunction in corneal endothelial cells (CEnCs). METHODS: In vitro experiments were conducted using immortalized normal human corneal endothelial cells (HCEnC-21T; SVN1-67F) and Fuchs endothelial corneal dystrophy (FECD) cells (SVF5-54F; SVF3-76M). Cells were pretreated with MitoQ or Idb and then exposed to menadione (MN) with simultaneous antioxidant treatment. Mitochondrial parameters were evaluated through adenosine triphosphate viability assays, JC-1 staining for mitochondrial membrane potential, and Tom-20 antibody staining for fragmentation, with analysis performed using ImageJ software. HCEnC-21T cells were additionally exposed to ultraviolet-A (25 J/cm 2 ) to assess drug effects under physiological stress. Mitochondrial fragmentation in FECD specimens was analyzed pre- and post-treatment with the drugs. Statistical analysis was conducted using 1-/2-way analysis of variance with post-hoc Tukey test. RESULTS: MitoQ and Idb enhanced cell viability and mitochondrial membrane potential in both normal and FECD cells under MN-induced stress. Idb reduced MN-induced mitochondrial fragmentation by 32% more than MitoQ in HCEnC-21T cells and by 13% more in SVF5-54F cells. Under ultraviolet-A stress, Idb and MitoQ improved mitochondrial function by 31% and 25%, respectively, with MitoQ increasing mitochondrial function by 42% in FECD specimens. CONCLUSIONS: Differential responses in mitochondrial dysfunction across cell lines highlight disease heterogeneity. MitoQ and Idb protected CEnCs from oxidative stress and improved mitochondrial bioenergetics, suggesting that mitochondrial-targeted antioxidants could be considered for mitochondrial dysfunction in CEnCs.