The Role of Adenosine Signaling in Obesity-Driven Type 2 Diabetes: Revisiting Mechanisms and Implications for Metabolic Regulation

The global prevalence of obesity and type 2 diabetes has increased considerably in recent decades, primarily due to behavioral changes associated with societal progress, such as increased consumption of high-calorie foods and sedentary lifestyles. Obesity is a disease of the energy homeostasis system, not merely a passive accumulation of fat. The hypothalamus serves as the regulatory center for energy balance, and together with peripheral organs, such as liver, pancreas, muscle and adipose tissue, controls food intake, energy expenditure, and whole-body metabolism. Adenosine, a product of ATP catabolism, exerts its effects through various G-protein-coupled receptors: A1R, A2AR, A2BR, and A3R. It plays a key role in regulating peripheral metabolism, including glucose homeostasis, insulin sensitivity, fat beta-oxidation, and lipolysis in adipose tissue. Beyond its roles in the CNS, adenosine receptors are also crucial in metabolic tissues, where they regulate glucose and lipid homeostasis and contribute to overall metabolic function. Several studies have been analyzing the role of adenosine system, specifically the adenosine receptors in the regulation of whole-body metabolism, and the importance of adenosine receptors in context of metabolic diseases and obesity. In this review, we provide an overview of the adenosine signaling system, highlighting its role in metabolic regulation as well as the pathophysiological mechanisms underlying obesity and type 2 diabetes.