The Role of Epicardial Adipose Tissue-Derived MicroRNAs in the Regulation of Cardiovascular Disease: A Narrative Review

SIMPLE SUMMARY: Cardiovascular diseases are the leading cause of death. Obesity has been associated with multiple pathologic cardiovascular-related conditions. Epicardial adipose tissue is likely the principal adipose tissue relevant to the development of cardiovascular disease due to its close location to the myocardium. Since miRNAs have been implicated in various diseases, including cardiovascular diseases, it is likely that the pathophysiology of epicardial adipose tissue in cardiovascular disease is also regulated by miRNAs. In the present review, we summarized miRNAs reported to be differentially expressed in human epicardial adipose tissue under pathologic conditions, focusing on their potential targets and their roles in the regulation of epicardial adipose tissue biology. As discussed in this review, it is clear that epicardial adipose tissue-derived miRNAs can make a vital contribution to the cardiovascular system both locally and systemically. However, much of the underlying mechanisms with which epicardial adipose tissue-derived miRNAs regulate both the physiology and pathophysiology of the cardiovascular system still largely remain speculative, requiring further studies. ABSTRACT: Cardiovascular diseases have been leading cause of death worldwide for many decades, and obesity has been acknowledged as a risk factor for cardiovascular diseases. In the present review, human epicardial adipose tissue-derived miRNAs reported to be differentially expressed under pathologic conditions are discussed and summarized. The results of the literature review indicate that some of the epicardial adipose tissue-derived miRNAs are believed to be cardioprotective, while some others show quite the opposite effects depending on the underlying pathologic conditions. Furthermore, they suggest that that the epicardial adipose tissue-derived miRNAs have great potential as both a diagnostic and therapeutic modality. Nevertheless, mainly due to highly limited availability of human samples, it is very difficult to make any generalized claims on a given miRNA in terms of its overall impact on the cardiovascular system. Therefore, further functional investigation of a given miRNA including, but not limited to, the study of its dose effect, off-target effects, and potential toxicity is required. We hope that this review can provide novel insights to transform our current knowledge on epicardial adipose tissue-derived miRNAs into clinically viable therapeutic strategies for preventing and treating cardiovascular diseases.