New concepts in white adipose tissue physiology

Abstract

Numerous studies address the physiology of adipose tissue (AT). The interest surrounding the physiology of AT is primarily the result of the epidemic outburst of obesity in various contemporary societies. Briefly, the two primary metabolic activities of white AT include lipogenesis and lipolysis. Throughout the last two decades, a new model of AT physiology has emerged. Although AT was considered to be primarily an abundant energy source, it is currently considered to be a prolific producer of biologically active substances, and, consequently, is now recognized as an endocrine organ. In addition to leptin, other biologically active substances secreted by AT, generally classified as cytokines, include adiponectin, interleukin-6, tumor necrosis factor-alpha, resistin, vaspin, visfatin, and many others now collectively referred to as adipokines. The secretion of such biologically active substances by AT indicates its importance as a metabolic regulator. Cell turnover of AT has also recently been investigated in terms of its biological role in adipogenesis. Consequently, the objective of this review is to provide a comprehensive critical review of the current literature concerning the metabolic (lipolysis, lipogenesis) and endocrine actions of AT.

Adipose Tissue as an Endocrine Organ: An Update on Pro-inflammatory and Anti-inflammatory Microenvironment

“…PGRN may function as a potential link between chronic inflammation and insulin resistance (Li et al, 2014). Also, omentin is a novel depot-specific adipokine in human AT with insulin-sensitizing effects and anti-inflammatory properties (Yang et al, 2006;Proença et al, 2014).…”

Circulating and peritoneal fluid interleukin-6 levels and gene expression in pelvic endometriosis

“…Eutopic and ectopic endometrial samples, as well as subcutaneous and visceral AT samples, were collected from the pelvic region before the end of the laparoscopy procedure: A single sample of superficial peritoneal endometriotic tissue was obtained from the largest lesion; subcutaneous and visceral AT samples (~1 cm 3 ) were harvested at the end of the procedure; and eutopic endometrial samples were harvested via curettage. Samples were immediately frozen in liquid nitrogen and stored at -80˚C until RNA isolation.…”

Cold Exposure as A Natural Tool to Treat Obesity in Humans

“…Overall, majority of the adipokines from WAT affect insulin functions, glucose metabolism and lipid metabolism negatively resulting in the development of metabolic syndrome features such as higher adiposity, hypertension, diabetes mellitus, cardiovascular effects and inflammatory process with other manifestations [8].…”

“…Some of these secretions act through autocrine, paracrine and endocrine routes. Many functions such as the metabolic, immunologic, energy balance, cardiovascular, inflammatory and hormonal signaling have been ascribed to these adipokines [8]. Major physiological roles of a few important adipokines are given in Table 1.…”