Adipose tissue is a complex organ containing mature adipocytes, preadipocytes, immune cells, sympathetic fibers, and endothelial cells, with profound effects on both physiology and pathophysiology. Traditionally, adipocytes are categorized into three types: white adipocytes, brown adipocytes, and beige adipocytes. In most mammals, white adipocytes are specialized for lipid storage and release, making up the bulk of adipose tissues in most animals. Excess calories are stored in white adipocytes in the form of triglycerides, and released via lipolysis during periods of fasting or thermoregulation. In contrast, brown adipocytes are specialized thermogenic cells able to dissipate nutritional energy in the form of heat. In addition to its role in energy storage and expenditure, adipose tissue is recognized as an indispensable endocrine organ responsible for the release of metabolites, lipids, and bioactive peptides, collectively referred to as adipokines.
In a review article published in Life Metabolism on 20 January, 2024, Dr. Qi-qun Tang's group at Fudan University, systematically reviewed the secretory function of adipose tissues in metabolic regulation (original link: https://doi.org/10.1093/lifemeta/loae003). They introduced the function of adipose-derived peptides, lipids, metabolites, and extracellular vesicles. These secretory factors, through autocrine and paracrine mechanisms, regulate various processes within adipose tissues, including adipogenesis, glucose and lipid metabolism, inflammation, and adaptive thermogenesis, all of which are essential for the maintenance of the balance and functionality of the adipose tissue micro-environment. A subset of these adipose-derived secretory factors can enter the circulation and target distant tissues to regulate appetite, cognitive function, energy expenditure, insulin secretion and sensitivity, gluconeogenesis, cardiovascular remodeling, and exercise capacity. In this review, they highlighted the role of adipose-derived secretory factors and their signaling pathways in modulating metabolic homeostasis. Furthermore, they delved into the alterations in both the content and secretion processes of these factors under various physiological and pathological conditions, shedding light on potential pharmacological treatment strategies for related diseases.
The role of adipokines in metabolic regulation (Created with BioRender.com)
Associate professor Yang Liu from the School of Basic Medical Sciences, Fudan University, is the first author of this review, and professor Qi-qun Tang is the corresponding author. This word was supported by National Key R&D Program of China and National Natural Science Foundation of China.