%0 Journal Article %J Invest Ophthalmol Vis Sci %D 2016 %T PGC-1α Induces Human RPE Oxidative Metabolism and Antioxidant Capacity. %A Iacovelli, Jared %A Rowe, Glenn C %A Khadka, Arogya %A Diaz-Aguilar, Daniel %A Spencer, Carrie %A Arany, Zoltan %A Saint-Geniez, Magali %X

PURPOSE: Oxidative stress and metabolic dysregulation of the RPE have been implicated in AMD; however, the molecular regulation of RPE metabolism remains unclear. The transcriptional coactivator, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) is a powerful mediator of mitochondrial function. This study examines the ability of PGC-1α to regulate RPE metabolic program and oxidative stress response. METHODS: Primary human fetal RPE (hfRPE) and ARPE-19 were matured in vitro using standard culture conditions. Mitochondrial mass of RPE was measured using MitoTracker staining and citrate synthase activity. Expression of PGC-1 isoforms, RPE-specific genes, oxidative metabolism proteins, and antioxidant enzymes was analyzed by quantitative PCR and Western blot. Mitochondrial respiration and fatty-acid oxidation were monitored using the Seahorse extracellular flux analyzer. Expression of PGC-1α was increased using adenoviral delivery. ARPE-19 were exposed to hydrogen peroxide to induce oxidative stress. Reactive oxygen species were measured by CM-H2DCFDA fluorescence. Cell death was analyzed by LDH release. RESULTS: Maturation of ARPE-19 and hfRPE was associated with significant increase in mitochondrial mass, expression of oxidative phosphorylation (OXPHOS) genes, and PGC-1α gene expression. Overexpression of PGC-1α increased expression of OXPHOS and fatty-acid β-oxidation genes, ultimately leading to the potent induction of mitochondrial respiration and fatty-acid oxidation. PGC-1α gain of function also strongly induced numerous antioxidant genes and, importantly, protected RPE from oxidant-mediated cell death without altering RPE functions. CONCLUSIONS: This study provides important insights into the metabolic changes associated with RPE functional maturation and identifies PGC-1α as a potent driver of RPE mitochondrial function and antioxidant capacity.

%B Invest Ophthalmol Vis Sci %V 57 %P 1038-51 %8 2016 Mar 1 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/26962700?dopt=Abstract %R 10.1167/iovs.15-17758