A Surgical Model for Graft of Brown Adipose Tissue on the Heart Surface in Mice

A mouse model for investigating the paracrine effects of browning epicardial adipose tissue (EAT) on coronary arteries and the myocardium should be developed. Due to its special anatomical location and direct connection to the heart surface, EAT is considered not only an energy storage organ but also an essential paracrine regulator involved in multiple cardiovascular diseases. Several studies have indicated that EAT browning holds promising therapeutic potential for cardiovascular diseases through anti-inflammatory phenotype transition, the release of cardioprotective factors, and extracellular vesicles, among other mechanisms. The congenital deficiency of EAT in rodent models limits experimental research on its function in cardiovascular diseases. Previous studies have utilized adipose tissue transplantation to investigate the endocrine and paracrine crosstalk between adipose tissue and other organs. This highlights the need to develop a surgical model for transplanting brown adipose tissue (BAT) onto the mouse heart surface to study its paracrine effects on cardiovascular diseases and explore the potential protective benefits of EAT browning. Herein, this study establishes a unique surgical procedure for grafting brown adipose tissue onto the heart surface in mice and evaluates graft survival and recipient viability four weeks after the operation. This model can be applied in future experiments to investigate EAT browning.