Adipose tissue: colors, depots and functions

Obesity is a chronic disease characterized by excessive accumulation of adipose tissue. The prevalence of obesity and associated diseases has prompted researchers to expand the study of the biology of adipose tissue. New technologies have significantly expanded the understanding of adipogenesis mechanisms, various aspects of lipid and glucose metabolism, as well as the paracrine and endocrine functions of adipose tissue. Adipose tissue is a complex, heterogeneous endocrine organ. The existence of several shades of adipocytes demonstrates their morphological and functional heterogeneity. The main function of white adipose tissue is to store energy. Brown and white adipocytes perform a predominantly thermogenic function. Bone marrow (yellow) adipose tissue regulates the processes of bone remodeling and hematopoiesis. Pink adipocytes are formed during pregnancy and satisfy the energy needs of the offspring. The study of the biology of adipose tissue is crucial to understanding the pathophysiology of obesity and determining its molecular relationships with type 2 diabetes as well as cardiovascular and oncological diseases. The review presents current literature data on the origin, adipogenesis, and functional properties of adipose tissue depending on its cellular composition and localization. It outlines the nature of changes in adipose tissue in obesity and the clinical significance and therapeutic potential of various adipose tissue depots.