Adipose Tissue-Derived Extracellular Vesicle MicroRNAs: Diagnostic Biomarkers for the Pathophysiology Associated with Obesity.

Obesity is a global health problem that increases the risk of type 2 diabetes, cardiovascular diseases, fatty liver disease, and cancer. The pathological outcomes of obesity and the responses to weight loss interventions vary significantly among individuals. The use of noninvasive biomarkers is critical for the early risk prediction of diseases associated with obesity and monitoring disease progression. MicroRNAs (miRNAs) are small noncoding RNAs that play pivotal roles in biological processes of adipose development, inflammation, and function. Dysregulation of numerous miRNAs has been implicated in the pathogenesis of obesity and associated diseases. In addition to exerting their function in the cytoplasm, mature miRNAs can be packaged into vesicles, released into extracellular space and body fluids, and act as paracrine and endocrine factors mediating intercellular and interorgan crosstalk. Encapsulation of miRNAs in extracellular vesicles (EVs) protects them from degradation and enhances their stability in body fluids. Moreover, the unique EV-miRNA signature reflects the state of the origin cells and is functionally related to disease pathology, supporting their potential as sensitive and specific biomarkers for clinical diagnostics. Adipose tissue is the main source of circulating EV-miRNAs in Obesity. Here we highlight the implication of adipose tissue-derived EV-miRNAs in metabolic disorders associated with obesity. Current understanding of the molecular mechanisms governing the sorting of miRNAs into EVs and recent advancements in relevant techniques are reviewed. In addition, limitations and future perspectives in this field are discussed.