The Heating Microenvironment: Intercellular Cross Talk Within Thermogenic Adipose Tissue

Abstract

Adipose tissue serves as the body’s primary energy storage site; however, findings in recent decades have transformed our understanding of the multifaceted roles of this adaptable organ. The ability of adipose tissue to undergo energy expenditure through heat generation is termed adaptive thermogenesis, a process carried out by thermogenic adipocytes. Adipocytes are the primary parenchymal cell type in adipose tissue, yet these cells are sustained within a rich stromal vascular microenvironment comprised of adipose stem cells and progenitors, immune cells, neuronal cells, fibroblasts, and endothelial cells. Intricate cross talk between these diverse cell types is essential in regulating the activation of thermogenic fat, and the past decade has shed significant light on how this intercellular communication functions. This review will draw upon recent findings and current perspectives on the sophisticated repertoire of cellular and molecular features that comprise the adipose thermogenic milieu.

Acetylcholine‐synthesizing macrophages in subcutaneous fat are regulated by β 2 ‐adrenergic signaling

“…A distinct functional niche for acetylcholine‐synthesizing cells is not unprecedented, given that ChAT‐expressing CD4 T cells have been described as a unique lymphocyte subset responsible for blood pressure regulation (Olofsson et al , 2016). Significant advances have been made in recent years regarding our understanding of functionally distinct macrophage subpopulations in fat—in particular within the obese and thermogenic adipose microenvironment (Pirzgalska et al , 2017; Hill et al , 2018; Chakarov et al , 2019; Jaitin et al , 2019; Knights et al , 2020a) (Fig EV2M–R). Given this inherent heterogeneity in tissue macrophages, future investigations will further reveal how cholinergic macrophages and other subsets fit into the functional milieu of resident immune cells—particularly in subcutaneous fat.…”

Vascularization of Microvascular Fragment Isolates from Visceral and Subcutaneous Adipose Tissue of Mice

“…Meanwhile it is well known that adipose tissue is not only a simple energy storage but a highly adaptive tissue with important endocrine and thermoregulatory functions as well as a complex composition of multiple cell types and extracellular matrix compounds [29,30]. Accordingly, it is not surprising that there are marked structural and functional differences between individual fat tissue types within the body [31][32][33].…”

Crosstalk between adipose tissue and the microbiota-gut-brain axis in metabolic diseases

“…Thermogenic adipose tissue, BAT and beige adipose tissue, is the core organ of non-shivering thermogenesis, the heating microenvironment homeostasis of which protects the body against cold and other extreme environments 109 , 110 . The thermogenic adipose tissue has abundant neural fibers, the efferent branches of which have been proven to possess sympathetic activity, constituting the sympathetic nervous system (SNS).…”