Abstract
The study of epicardial adipose tissue (EAT) has been limited by its accessibility due to its proximity to the heart. Moreover, many common animal models do not have EAT, leaving its functional role underestimated and poorly elucidated. Recent advances in medicine and science have allowed for better studies that provide a more comprehensive understanding of its physiological role. One way to dissect its function is the study of its gene expression. In this chapter, we summarize transcriptomic and proteomic analyses which show that EAT expresses a unique set of genes setting it apart from other adipose tissues in the body. This distinctive set of genes modulates a feedback mechanism that has direct interaction with the myocardium. The EAT shares its blood supply with the coronary arteries and innervation with the cardiac muscle, provides physical protection, and regulates energetic metabolites needed by the myocardium. Transcriptomic and proteomic studies show that it is a local source of adipokines with paracrine influence on the myocardium due to the intimate microcirculation shared by both tissues. These analyses also show that it has a role in the immune and endocrine systems affecting the rest of the body. Furthermore, regulation of EAT gene expression is not monolithic and can be affected by multiple factors such as sex, age, underling disease, medication, etc. Gene expression studies can therefore provide great insight into the function of EAT and its role in health and disease.