An update on the secretory functions of brown, white, and beige adipose tissue: Towards therapeutic applications

Abstract

Adipose tissue, including white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, is vital in modulating whole-body energy metabolism. While WAT primarily stores energy, BAT dissipates energy as heat for thermoregulation. Beige adipose tissue is a hybrid form of adipose tissue that shares characteristics with WAT and BAT. Dysregulation of adipose tissue metabolism is linked to various disorders, including obesity, type 2 diabetes, cardiovascular diseases, cancer, and infertility. Both brown and beige adipocytes secrete multiple molecules, such as batokines, packaged in extracellular vesicles or as soluble signaling molecules that play autocrine, paracrine, and endocrine roles. A greater understanding of the adipocyte secretome is essential for identifying novel molecular targets in treating metabolic disorders. Additionally, microRNAs show crucial roles in regulating adipose tissue differentiation and function, highlighting their potential as biomarkers for metabolic disorders. The browning of WAT has emerged as a promising therapeutic approach in treating obesity and associated metabolic disorders. Many browning agents have been identified, and nanotechnology-based drug delivery systems have been developed to enhance their efficacy. This review scrutinizes the characteristics of and differences between white, brown, and beige adipose tissues, the molecular mechanisms involved in the development of the adipocytes, the significant roles of batokines, and regulatory microRNAs active in different adipose tissues. Finally, the potential of WAT browning in treating obesity and atherosclerosis, the relationship of BAT with cancer and fertility disorders, and the crosstalk between adipose tissue with circadian system and circadian disorders are also investigated.

Dynamic changes of immunocyte subpopulations in thermogenic activation of adipose tissues

“…The activation of BAT or SAT has emerged as a potential strategy for combating obesity and its related metabolic diseases ( 33 , 34 ). However, the immunomodulation of these adipose tissues, especially under cold exposure, is still not well understood.…”

Early Life Programming of Adipose Tissue Remodeling and Browning Capacity by Micronutrients and Bioactive Compounds as a Potential Anti-Obesity Strategy

“…WAT specializes in energy storage and release and is composed primarily of white adipocytes, while BAT specializes in regulated heat production (adaptive thermogenesis) and is composed primarily of brown adipocytes. WAT and BAT also have distinct endocrine functions [23]. The key to BAT thermogenic function is the high oxidative capacity, mitochondrial content, and characteristic expression of uncoupling protein 1 (UCP1) in brown adipocytes.…”

Conjugated linoleic acid (CLA) reduces HFD‐induced obesity by enhancing BAT thermogenesis and iWAT browning via the CD36–AMPK pathway

“…has not yet been established. Different from the excessive deposition of white adipose tissue (WAT) which causes obesity, brown adipose tissue (BAT) plays a role in enhancing energy metabolism 9 and antiobesity. [10][11][12] Based on that, we elucidated the mechanism of CLA alleviating obesity from the aspects of BAT thermogenesis and inguinal subcutaneous white adipose tissue (iWAT) browning.…”