Loss of the transcriptional repressor Rev-erbα upregulates metabolism and proliferation in cultured mouse embryonic fibroblasts.

The transcriptional repressor Rev-erbα is known to down-regulate fatty acid metabolism and gluconeogenesis gene expression. In animal models, disruption of Rev-erbα results in global changes in exercise performance, oxidative capacity, and blood glucose levels. However, the complete extent to which Rev-erbα-mediated transcriptional repression of metabolism impacts cell function remains unknown. We hypothesized that loss of Rev-erbα in a mouse embryonic fibroblast (MEF) model would result in global changes in metabolism. MEFs lacking Rev-erbα exhibited a hypermetabolic phenotype, demonstrating increased levels of glycolysis and oxidative phosphorylation. Rev-erbα deletion increased expression of hexokinase II, transketolase, and ribose-5-phosphate isomerase genes involved in glycolysis and the pentose phosphate pathway (PPP), and these effects were not mediated by the transcriptional activator BMAL1. Upregulation of oxidative phosphorylation was not accompanied by an increase in mitochondrial biogenesis or numbers. Rev-erbα repressed proliferation via glycolysis, but not the PPP. When treated with H