MicroRNAs in metabolic syndrome: Mechanisms, diagnosis, and therapy

Metabolic syndrome is a group of cardio-metabolic dysfunctions characterized by increased fasting blood glucose, blood pressure, waist circumference, triglycerides, and decreased high-density lipoprotein cholesterol. Globally, the prevalence of metabolic syndrome ranged from 12.5-31.4 %, among which 5-7 % were young adults. Environmental factors, nutrition, and genetic and epigenetic predispositions are thought to interact intricately to cause metabolic disease. MicroRNAs are short, small non-coding RNAs that attach to the target coding sequences and untranslated genomic regions in many cell types, thereby post-transcriptionally suppressing gene expression. The human genome contains around 2000 microRNAs many of which appear linked to a numerous biologic and pathophysiologic processes, such as inflammatory response, angiogenesis, and glucose homeostasis. Many human disorders, including obesity, type 2 diabetes mellitus, and cardiovascular disorders, have been linked to deregulated microRNA expression. More recently, the identification of extracellular microRNAs has highlighted their potential as markers of disease and endocrine signaling molecules. This review provides an overview of microRNA biogenesis and its function in insulin signaling, adipogenesis, biology of pancreatic β-cell, and metabolism. We review current research on microRNAs linked to vascular diabetic complications and metabolic diseases, with a focus on their diagnostic and therapeutic potential.