Martin Sally
Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
Horm Mol Biol Clin Investig. 2013 Sep;15(1):11-8. doi: 10.1515/hmbci-2013-0035.
Adipocytes are specialized cells that function to store energy in the form of lipids, predominantly triglycerides (TGs), and as a regulatory system contributing to metabolic homoeostasis through the production and secretion of hormones and cytokines. The regulation of lipid homeostasis by adipose tissue is an important aspect of whole-body metabolism. Owing to the central nature of adipose tissue in lipid metabolism, dysregulation has wide-ranging effects, contributing to disorders as diverse as diabetes, cardiovascular disease, cancer, and neurodegeneration. Excess lipids are stored in specialized organelles called lipid droplets (LDs). The surface of the lipid droplet can be considered a highly regulated membrane domain that both protects the contents of the LD from unregulated lipolysis and the cell from the cytotoxic effects of elevated free fatty acids. The surface of the LD is coated with a variety of regulatory proteins, either resident or transiently associated, including enzymes involved in the breakdown of TG, lipid transport proteins, and cofactors. Recent studies have begun to unravel the range of LD-associated proteins and to define their functional significance. Importantly, the involvement of LD proteins in pathophysiological disorders is beginning to be understood. This review will outline recent advances in defining the diversity of LD-associated proteins and their links to metabolic disorders including the integral membrane protein, caveolin-1 (CAV1). Analysis of the role of CAV1 in adipose tissue has highlighted the interconnectedness between the regulation of lipid storage and the function of the adipocyte plasma membrane.
脂肪细胞是一种特殊的细胞，其功能是以脂质（主要是甘油三酯，TGs）的形式储存能量，并作为一个调节系统，通过激素和细胞因子的产生与分泌来维持代谢稳态。脂肪组织对脂质稳态的调节是全身代谢的一个重要方面。由于脂肪组织在脂质代谢中处于核心地位，其调节异常会产生广泛影响，导致糖尿病、心血管疾病、癌症和神经退行性疾病等多种病症。多余的脂质储存在称为脂滴（LDs）的特殊细胞器中。脂滴表面可被视为一个高度受调控的膜结构域，它既能保护脂滴内容物免受不受控制的脂解作用影响，又能保护细胞免受游离脂肪酸升高带来的细胞毒性作用。脂滴表面覆盖着各种调节蛋白，包括常驻蛋白或瞬时相关蛋白，其中有参与甘油三酯分解的酶、脂质转运蛋白和辅助因子。最近的研究已开始揭示与脂滴相关的蛋白质种类，并确定它们的功能意义。重要的是，脂滴蛋白在病理生理紊乱中的作用也开始被人们所了解。本综述将概述在确定与脂滴相关的蛋白质多样性及其与代谢紊乱（包括整合膜蛋白小窝蛋白 -1，CAV1）的联系方面的最新进展。对CAV1在脂肪组织中的作用分析突出了脂质储存调节与脂肪细胞质膜功能之间的相互联系。
