Obesity-associated exosomal miRNAs modulate glucose and lipid metabolism in mice

Abstract

Obesity is frequently associated with metabolic disease. Here, we show that obesity changes the miRNA profile of plasma exosomes in mice, including increases in miR-122, miR-192, miR-27a-3p, and miR-27b-3p. Importantly, treatment of lean mice with exosomes isolated from obese mice induces glucose intolerance and insulin resistance. Moreover, administration of control exosomes transfected with obesity-associated miRNA mimics strongly induces glucose intolerance in lean mice and results in central obesity and hepatic steatosis. Expression of the candidate target gene Ppara is decreased in white adipose tissue but not in the liver of mimic-treated (MIMIC) mice, and this is accompanied by increased circulating free fatty acids and hypertriglyceridemia. Treatment with a specific siRNA targeting Ppara transfected into exosomes recapitulates the phenotype induced by obesity-associated miRNAs. Importantly, simultaneously reducing free fatty acid plasma levels in MIMIC mice with either the lipolysis inhibitor acipimox or the PPARα agonist fenofibrate partially protects against these metabolic alterations. Overall, our data highlight the central role of obesity-associated exosomal miRNAs in the etiopathogeny of glucose intolerance and dyslipidemia.