Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Piazza Giulio Cesare, 11, 70124, Bari, Italy.
J Endocrinol Invest. 2021 May;44(5):921-941. doi: 10.1007/s40618-020-01446-8. Epub 2020 Nov 3.
The way by which subcutaneous adipose tissue (SAT) expands and undergoes remodeling by storing excess lipids through expansion of adipocytes (hypertrophy) or recruitment of new precursor cells (hyperplasia) impacts the risk of developing cardiometabolic and respiratory diseases. In unhealthy obese subjects, insulin resistance, type 2 diabetes, hypertension, and obstructive sleep apnoea are typically associated with pathologic SAT remodeling characterized by adipocyte hypertrophy, as well as chronic inflammation, hypoxia, increased visceral adipose tissue (VAT), and fatty liver. In contrast, metabolically healthy obese individuals are generally associated with SAT development characterized by the presence of smaller and numerous mature adipocytes, and a lower degree of VAT inflammation and ectopic fat accumulation. The remodeling of SAT and VAT is under genetic regulation and influenced by inherent depot-specific differences of adipose tissue-derived stem cells (ASCs). ASCs have multiple functions such as cell renewal, adipogenic capacity, and angiogenic properties, and secrete a variety of bioactive molecules involved in vascular and extracellular matrix remodeling. Understanding the mechanisms regulating the proliferative and adipogenic capacity of ASCs from SAT and VAT in response to excess calorie intake has become a focus of interest over recent decades. Here, we summarize current knowledge about the biological mechanisms able to foster or impair the recruitment and adipogenic differentiation of ASCs during SAT and VAT development, which regulate body fat distribution and favorable or unfavorable metabolic responses.
皮下脂肪组织(SAT)通过储存多余的脂肪来扩张和重塑的方式,通过脂肪细胞的扩张(肥大)或新前体细胞的募集(增生)来影响发生心脏代谢和呼吸疾病的风险。在不健康的肥胖人群中,胰岛素抵抗、2 型糖尿病、高血压和阻塞性睡眠呼吸暂停通常与病理性 SAT 重塑有关,其特征是脂肪细胞肥大,以及慢性炎症、缺氧、内脏脂肪组织(VAT)增加和脂肪肝。相比之下,代谢健康的肥胖个体通常与 SAT 发展有关,其特征是存在更小、更多成熟的脂肪细胞,以及较低程度的 VAT 炎症和异位脂肪堆积。SAT 和 VAT 的重塑受遗传调控,并受脂肪组织源性干细胞(ASCs)固有的库特异性差异的影响。ASCs 具有多种功能,如细胞更新、脂肪生成能力和血管生成特性,并分泌多种参与血管和细胞外基质重塑的生物活性分子。了解调节 SAT 和 VAT 中 ASC 对过量热量摄入的增殖和脂肪生成能力的机制,已成为近几十年来的研究重点。在这里,我们总结了目前关于能够促进或损害 SAT 和 VAT 发育过程中 ASC 募集和脂肪生成分化的生物学机制的知识,这些机制调节体脂肪分布和有利或不利的代谢反应。