Brown adipose tissue and regulation of human body weight

Abstract

Background Approximately 30% of the global population is affected by obesity. Traditional non‐surgical measures for weight loss have limited efficacy and tolerability. Therefore, there is a need for novel, effective therapies. Brown adipose tissue (BAT) has been implicated in physiological energy expenditure, indicating that it could be targeted to achieve weight loss in humans. The use of 18F‐fluorodeoxyglucose (18F‐FDG) positron emission tomography—computed tomography—(PET‐CT) imaging has enabled the discovery of functionally active BAT in the supraclavicular, subclavian, and thoracic spine regions of human adults. This review aims to discuss the reasons behind the renewed interest in BAT, assess whether it is metabolically important in humans, and evaluate its feasibility as a therapeutic target for treating obesity. Sources of material PubMed Central, Europe PMC, Medline. Findings In vivo studies have shown that BAT activity is regulated by thyroid hormones and the sympathetic nervous system. Furthermore, BAT uniquely contains uncoupling protein 1 (UCP1) that is largely responsible for non‐shivering thermogenesis. Cold exposure can increase BAT recruitment through the browning of white adipose tissue (WAT); however, this technique has practical limitations that may preclude its use. Currently available medicines for humans, such as the β3‐adrenergic receptor agonist mirabegron or the farnesoid X receptor agonist obeticholic acid, have generated excitement, although adverse effects are a concern. Capsinoids represent a tolerable alternative, which require further investigation. Conclusions The use of currently available BAT‐activating agents alone is unlikely to achieve significant weight loss in humans. A combination of BAT activation with physical exercise and modern, successful dietary strategies represents a more realistic option.

Theabrownin from Fu Brick tea ameliorates high-fat induced insulin resistance, hepatic steatosis, and inflammation in mice by altering the composition and metabolites of gut microbiota

“…Brown adipose tissue, on the other hand, has a larger number of mitochondria harboring uncoupling protein 1 (UCP1) and multi-chambered lipid droplets, serving as a heat-producing adipose tissue. [45][46][47] TB increases adipose browning via the AMPK-PGC1 signaling pathway and upregulates thermogenic gene expression of UCP-1, peroxisome proliferator-activated receptor-γ coactlvator-1α (PGC-1α), and PR domain zinc finger protein 16 (PRDM16). These genes serve as indicators of brown adipose tissue and regulate the molecular switch for browning of adipose tissue.…”

Main mechanisms and clinical implications of alterations in energy expenditure state among patients with pheochromocytoma and paraganglioma: A review

“…Therapeutically activating BAT to increase energy expenditure by stimulating fat utilization has gained attention. [123] Thus, PPGL may serve as a natural human model for inducing BAT activation.…”

Mirabegron, a Selective β3-Adrenergic Receptor Agonist, as a Potential Anti-Obesity Drug

“…WAT is responsible for storing energy in the form of triglycerides, releasing lipids and serving as an endocrine gland, secreting adipokines, such as adiponectin and leptin to promote metabolic homeostasis [9,12]. In obesity, white adipocytes become hypertrophied, followed by fibrosis, adipocyte necrosis, and immune cell infiltration, which leads to local and systemic inflammation, insulin resistance, and metabolic dysfunction [9].…”