UCP1 Dependent and Independent Thermogenesis in Brown and Beige Adipocytes.

Kenji Ikeda,Tetsuya Yamada

doi:10.3389/fendo.2020.00498

Abstract

Mammals have two types of thermogenic adipocytes: brown adipocytes and beige adipocytes. Thermogenic adipocytes express high levels of uncoupling protein 1 (UCP1) to dissipates energy in the form of heat by uncoupling the mitochondrial proton gradient from mitochondrial respiration. There is much evidence that UCP1 is the center of BAT thermogenesis and systemic energy homeostasis. Recently, UCP1 independent thermogenic pathway identified in thermogenic adipocytes. Importantly, the thermogenic pathways are different in brown and beige adipocytes. Ca2+-ATPase 2b calcium cycling mechanism is selective to beige adipocytes. It remains unknown how the multiple thermogenic mechanisms are coordinately regulated. The discovery of UCP1-independent thermogenic mechanisms potential offer new opportunities for improving obesity and type 2 diabetes particularly in groups such as elderly and obese populations who do not possess UCP1 positive adipocytes.

Highlights

Reviewed by: Vibha Singhal, Massachusetts General Hospital, United States Marco Infante, University of Miami, United States
Our study showed that beige fat dramatically contributes to whole-body energy and glucose homeostasis via uncoupling protein 1 (UCP1)-independent metabolic mechanisms
fibroblast growth factor 21 (FGF21) and UCP1 are not required for cold environment acclimation in mice [71]. These findings suggest that at least some of the metabolic actions of FGF21 are mediated via UCP1-independent thermogenesis in adipose tissue

Summary

Introduction

Reviewed by: Vibha Singhal, Massachusetts General Hospital, United States Marco Infante, University of Miami, United States. Mammals have brown and beige thermogenic adipocytes, which are both rich in mitochondria and express uncoupling protein 1 (UCP1). UCP1-DEPENDENT THERMOGENESIS IN THERMOGENIC FAT: BROWN AND BEIGE ADIPOCYTES Ucp1 KO mice fed a high-fat diet (HFD) were resistant to the development of obesity at room temperature, suggesting the activation of a UCP1-independent thermogenic pathway [18, 32].

Results

Conclusion