Wade Gina, McGahee Ayren, Ntambi James M, Simcox Judith
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States.
Front Physiol. 2021 Dec 23;12:787535. doi: 10.3389/fphys.2021.787535. eCollection 2021.
Non-shivering thermogenesis is an energy demanding process that primarily occurs in brown and beige adipose tissue. Beyond regulating body temperature, these thermogenic adipocytes regulate systemic glucose and lipid homeostasis. Historically, research on thermogenic adipocytes has focused on glycolytic metabolism due to the discovery of active brown adipose tissue in adult humans through glucose uptake imaging. The importance of lipids in non-shivering thermogenesis has more recently been appreciated. Uptake of circulating lipids into thermogenic adipocytes is necessary for body temperature regulation and whole-body lipid homeostasis. A wide array of circulating lipids contribute to thermogenic potential including free fatty acids, triglycerides, and acylcarnitines. This review will summarize the mechanisms and regulation of lipid uptake into brown adipose tissue including protein-mediated uptake, lipoprotein lipase activity, endocytosis, vesicle packaging, and lipid chaperones. We will also address existing gaps in knowledge for cold induced lipid uptake into thermogenic adipose tissue.
非颤抖性产热是一个消耗能量的过程，主要发生在棕色和米色脂肪组织中。除了调节体温外，这些产热脂肪细胞还调节全身的葡萄糖和脂质稳态。从历史上看，由于通过葡萄糖摄取成像在成年人体内发现了活跃的棕色脂肪组织，对产热脂肪细胞的研究一直集中在糖酵解代谢上。脂质在非颤抖性产热中的重要性最近才得到重视。循环脂质摄取到产热脂肪细胞中对于体温调节和全身脂质稳态是必要的。多种循环脂质有助于产热潜能，包括游离脂肪酸、甘油三酯和酰基肉碱。本综述将总结脂质摄取到棕色脂肪组织中的机制和调节，包括蛋白质介导的摄取、脂蛋白脂肪酶活性、内吞作用、囊泡包装和脂质伴侣。我们还将探讨在寒冷诱导脂质摄取到产热脂肪组织方面现有知识的空白。
