Albert Verena, Svensson Kristoffer, Shimobayashi Mitsugu, Colombi Marco, Muñoz Sergio, Jimenez Veronica, Handschin Christoph, Bosch Fatima, Hall Michael N
Biozentrum, University of Basel, Basel, Switzerland.
Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain.
EMBO Mol Med. 2016 Mar 1;8(3):232-46. doi: 10.15252/emmm.201505610.
Activation of non-shivering thermogenesis (NST) in brown adipose tissue (BAT) has been proposed as an anti-obesity treatment. Moreover, cold-induced glucose uptake could normalize blood glucose levels in insulin-resistant patients. It is therefore important to identify novel regulators of NST and cold-induced glucose uptake. Mammalian target of rapamycin complex 2 (mTORC2) mediates insulin-stimulated glucose uptake in metabolic tissues, but its role in NST is unknown. We show that mTORC2 is activated in brown adipocytes upon β-adrenergic stimulation. Furthermore, mice lacking mTORC2 specifically in adipose tissue (AdRiKO mice) are hypothermic, display increased sensitivity to cold, and show impaired cold-induced glucose uptake and glycolysis. Restoration of glucose uptake in BAT by overexpression of hexokinase II or activated Akt2 was sufficient to increase body temperature and improve cold tolerance in AdRiKO mice. Thus, mTORC2 in BAT mediates temperature homeostasis via regulation of cold-induced glucose uptake. Our findings demonstrate the importance of glucose metabolism in temperature regulation.
褐色脂肪组织(BAT)中非颤抖性产热(NST)的激活已被提议作为一种抗肥胖治疗方法。此外,寒冷诱导的葡萄糖摄取可使胰岛素抵抗患者的血糖水平正常化。因此,识别NST和寒冷诱导的葡萄糖摄取的新型调节因子很重要。雷帕霉素复合物2(mTORC2)的哺乳动物靶点介导代谢组织中胰岛素刺激的葡萄糖摄取,但其在NST中的作用尚不清楚。我们发现,β-肾上腺素能刺激后,褐色脂肪细胞中的mTORC2被激活。此外,脂肪组织中特异性缺乏mTORC2的小鼠(AdRiKO小鼠)体温过低,对寒冷的敏感性增加,寒冷诱导的葡萄糖摄取和糖酵解受损。通过过表达己糖激酶II或激活的Akt2恢复BAT中的葡萄糖摄取足以提高AdRiKO小鼠的体温并改善其耐寒性。因此,BAT中的mTORC2通过调节寒冷诱导的葡萄糖摄取来介导体温稳态。我们的研究结果证明了葡萄糖代谢在体温调节中的重要性。