The circadian gene Rev-erbα improves cellular bioenergetics and provides preconditioning for protection against oxidative stress

• Published in: Free radical biology & medicine Vol. 93; pp. 177 - 189
• Main Authors: Sengupta, Shaon, Yang, Guang, O’Donnell, John C, Hinson, Maurice D., McCormack, Shana E., Falk, Marni J., La, Ping, Robinson, Michael B, Williams, Monica L., Yohannes, Mekdes T., Polyak, Erzsebet, Nakamaru-Ogiso, Eiko, Dennery, Phyllis A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2016
• Subjects: Animals; Antioxidants - metabolism; Bioenergetics; Catalase - biosynthesis; Circadian; Energy metabolism; Energy Metabolism - genetics; Fibroblasts - metabolism; Heme Oxygenase-1 - biosynthesis; Hydrogen Peroxide - metabolism; Mice; Mice, Transgenic; Mitochondria; Mitochondria - genetics; Mitochondria - metabolism; NR1D1; Nuclear Receptor Subfamily 1, Group D, Member 1 - genetics; Nuclear Receptor Subfamily 1, Group D, Member 1 - metabolism; Oxidative stress; Oxidative Stress - genetics; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - biosynthesis; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - genetics; Peroxisome proliferator‐activated receptor gamma coactivator 1‐alpha (PGC‐1α)(PPARGC1A); Preconditioning; Superoxide Dismutase - biosynthesis; Oxidative stress; Mitochondria; Energy metabolism; Bioenergetics; Peroxisome proliferator‐activated receptor gamma coactivator 1‐alpha (PGC‐1α)(PPARGC1A); NR1D1; Circadian; Preconditioning
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2016.02.004

Diurnal oscillations in the expression of antioxidant genes imply that protection against oxidative stress is circadian-gated. We hypothesized that stabilization of the core circadian gene Rev-erbα (Nr1d1) improves cellular bioenergetics and protects against nutrient deprivation and oxidative stress. Compared to WT, mouse lung fibroblasts (MLG) stably transfected with a degradation resistant Rev-erbα (Ser55/59 to Asp; hence referred to as SD) had 40% higher protein content, 1.5-fold higher mitochondrial area (confocal microscopy), doubled oxidative phosphorylation by high-resolution respirometry (Oroboros) and were resistant to glucose deprivation for 24h. This resulted from a 4-fold reduction in mitophagy (L3CB co-localized with MitoTracker Red) versus WT. Although PGC1α protein expression was comparable between SD and WT MLG cells, the role of mitochondrial biogenesis in explaining increased mitochondrial mass in SD cells was less clear. Embryonic fibroblasts (MEF) from C57Bl/6-SD transgenic mice, had a 9-fold induction of FoxO1 mRNA and increased mRNA of downstream antioxidant targets heme oxygenase-1 (HO-1), Mn superoxide dismutase and catalase (1.5, 2 fold and 2 fold respectively) versus WT. This allowed the SD cells to survive 1h incubation with 500µM H2O2 as well as 24h of exposure to 95% O2 and remain attached whereas most WT cells did not. These observations establish a mechanistic link between the metabolic functions of Rev-erbα with mitochondrial homeostasis and protection against oxidative stress. [Display omitted] •Circadian gene Rev-erbα, preconditions and protects cells against oxidative damage.•Rev-erbα increases mitochondrial respiration via an increase in mitochondrial mass.•Rev-erbα induces FoxO1 and protects cells against nutrient deprivation.