The Peroxisome Proliferator-activated Receptor γ Coactivator 1 α/β (PGC-1) Coactivators Repress the Transcriptional Activity of NF-κB in Skeletal Muscle Cells

A persistent, low-grade inflammation accompanies many chronic diseases that are promoted by physical inactivity and improved by exercise. The beneficial effects of exercise are mediated in large part by peroxisome proliferator-activated receptor gamma coactivator (PGC) 1 alpha, whereas its loss correlates with propagation of local and systemic inflammatory markers. We examined the influence of PGC-1 alpha and the related PGC-1 beta on inflammatory cytokines upon stimulation of muscle cells with TNF alpha, Toll-like receptor agonists, and free fatty acids. PGC-1s differentially repressed expression of proinflammatory cytokines by targeting NF-kappa B signaling. Interestingly, PGC-1 alpha and PGC-1 beta both reduced phoshorylation of the NF-kappa B family member p65 and thereby its transcriptional activation potential. Taken together, the data presented here show that the PGC-1 coactivators are able to constrain inflammatory events in muscle cells and provide a molecular link between metabolic and immune pathways. The PGC-1s therefore represent attractive targets to not only improve metabolic health in diseases like type 2 diabetes but also to limit the detrimental, low-grade inflammation in these patients.