PGC-1α Is a Key Regulator of Glucose-Induced Proliferation and Migration in Vascular Smooth Muscle Cells

Background: Atherosclerosis is a complex pathological condition caused by a number of mechanisms including the accelerated proliferation of vascular smooth muscle cells (VSMCs). Diabetes is likely to be an important risk factor for atherosclerosis, as hyperglycemia induces vascular smooth muscle cell (VSMC) proliferation and migration and may thus contribute to the formation of atherosclerotic lesions. This study was performed to investigate whether PGC-1 alpha, a PPAR gamma coactivator and metabolic master regulator, plays a role in regulating VSMC proliferation and migration induced by high glucose. Methodology/Principal Findings: PGC-1 alpha mRNA levels are decreased in blood vessel media of STZ-treated diabetic rats. In cultured rat VSMCs, high glucose dose-dependently inhibits PGC-1 alpha mRNA expression. Overexpression of PGC-1 alpha either by infection with adenovirus, or by stimulation with palmitic acid, significantly reduces high glucose-induced VSMC proliferation and migration. In contrast, suppression of PGC-1 alpha by siRNA mimics the effects of glucose on VSMCs. Finally, mechanistic studies suggest that PGC-1 alpha-mediated inhibition of VSMC proliferation and migration is regulated through preventing ERK1/2 phosphorylation. Conclusions/Significance: These results indicate that PGC-1 alpha is a key regulator of high glucose-induced proliferation and migration in VSMCs, and suggest that elevation of PGC-1 alpha in VSMC could be a useful strategy in preventing the development of diabetic atherosclerosis.