Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
Nat Commun. 2020 Mar 23;11(1):1517. doi: 10.1038/s41467-020-15328-3.
Leptin stimulates the sympathetic nervous system (SNS), energy expenditure, and weight loss; however, the underlying molecular mechanism remains elusive. Here, we uncover Sh2b1 in leptin receptor (LepR) neurons as a critical component of a SNS/brown adipose tissue (BAT)/thermogenesis axis. LepR neuron-specific deletion of Sh2b1 abrogates leptin-stimulated sympathetic nerve activation and impairs BAT thermogenic programs, leading to reduced core body temperature and cold intolerance. The adipose SNS degenerates progressively in mutant mice after 8 weeks of age. Adult-onset ablation of Sh2b1 in the mediobasal hypothalamus also impairs the SNS/BAT/thermogenesis axis; conversely, hypothalamic overexpression of human SH2B1 has the opposite effects. Mice with either LepR neuron-specific or adult-onset, hypothalamus-specific ablation of Sh2b1 develop obesity, insulin resistance, and liver steatosis. In contrast, hypothalamic overexpression of SH2B1 protects against high fat diet-induced obesity and metabolic syndromes. Our results unravel an unrecognized LepR neuron Sh2b1/SNS/BAT/thermogenesis axis that combats obesity and metabolic disease.
瘦素刺激交感神经系统(SNS)、能量消耗和体重减轻;然而,潜在的分子机制仍不清楚。在这里,我们发现瘦素受体(LepR)神经元中的 Sh2b1 是 SNS/棕色脂肪组织(BAT)/产热轴的关键组成部分。LepR 神经元特异性缺失 Sh2b1 会阻断瘦素刺激的交感神经激活,并损害 BAT 的产热程序,导致核心体温降低和对寒冷的不耐受。脂肪组织中的 SNS 在突变小鼠中会在 8 周龄后逐渐退化。成年后中脑下丘脑 Sh2b1 的消融也会损害 SNS/BAT/产热轴;相反,下丘脑过表达人类 SH2B1 则会产生相反的效果。LepR 神经元特异性或成年后、下丘脑特异性 Sh2b1 消融的小鼠会发展为肥胖、胰岛素抵抗和肝脂肪变性。相比之下,下丘脑过表达 SH2B1 可预防高脂肪饮食诱导的肥胖和代谢综合征。我们的研究结果揭示了一个以前未被识别的瘦素受体神经元 Sh2b1/SNS/BAT/产热轴,它可以对抗肥胖和代谢疾病。