MicroRNAs: emerging roles in lipid and lipoprotein metabolism.

PURPOSE OF REVIEW MicroRNAs (miRNAs) regulate gene expression by binding to target mRNAs and control a wide range of biological functions. Recent reports have identified specific miRNAs as major regulators of fatty acid and cholesterol homeostasis. This review examines the biological function of various miRNAs and the emerging evidence linking specific miRNAs to critical pathways in lipid metabolism. RECENT FINDINGS Disruption of lipid balance can lead to metabolic disturbances and thus tight regulation is required to maintain lipid homeostasis. Recent studies have shown key roles for miR-33 and miR-122 in regulation of lipid metabolism, and further evidence implicates miR-370 in regulation of miR-122. In addition, miRNAs involved in adipogenesis (miR-378/378* and miR-27) as well as newly discovered miRNAs such as miR-613, miR-302a, and miR-168 have now been implicated in regulation of lipid metabolism. SUMMARY Growing evidence support key roles for miRNAs in regulating both cholesterol and fatty acid metabolism, leading to considerable interest in miRNAs as potential drug targets to modulate lipid and lipoprotein metabolism. MiRNA-based therapeutics hold considerable promise in the fight to curtail the growing epidemic of obesity and type 2 diabetes and the associated risk of atherosclerosis.