脑内 Rheb1 的基因缺失可减少食物摄入,并导致外周代谢改变的低血糖症。
Genetic deletion of Rheb1 in the brain reduces food intake and causes hypoglycemia with altered peripheral metabolism.
机构信息
Laboratory of Molecular Neurobiology, State Key Laboratory of Biotherapy/West China Hospital, Sichuan University, Chengdu 610041, China.
West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
出版信息
Int J Mol Sci. 2014 Jan 21;15(1):1499-510. doi: 10.3390/ijms15011499.
Excessive food/energy intake is linked to obesity and metabolic disorders, such as diabetes. The hypothalamus in the brain plays a critical role in the control of food intake and peripheral metabolism. The signaling pathways in hypothalamic neurons that regulate food intake and peripheral metabolism need to be better understood for developing pharmacological interventions to manage eating behavior and obesity. Mammalian target of rapamycin (mTOR), a serine/threonine kinase, is a master regulator of cellular metabolism in different cell types. Pharmacological manipulations of mTOR complex 1 (mTORC1) activity in hypothalamic neurons alter food intake and body weight. Our previous study identified Rheb1 (Ras homolog enriched in brain 1) as an essential activator of mTORC1 activity in the brain. Here we examine whether central Rheb1 regulates food intake and peripheral metabolism through mTORC1 signaling. We find that genetic deletion of Rheb1 in the brain causes a reduction in mTORC1 activity and impairs normal food intake. As a result, Rheb1 knockout mice exhibit hypoglycemia and increased lipid mobilization in adipose tissue and ketogenesis in the liver. Our work highlights the importance of central Rheb1 signaling in euglycemia and energy homeostasis in animals.
过量的食物/能量摄入与肥胖和代谢紊乱有关,如糖尿病。大脑中的下丘脑在控制食物摄入和外周代谢方面起着关键作用。需要更好地了解调节食物摄入和外周代谢的下丘脑神经元中的信号通路,以便开发药理学干预措施来管理饮食行为和肥胖。哺乳动物雷帕霉素靶蛋白 (mTOR) 是一种丝氨酸/苏氨酸激酶,是不同细胞类型中细胞代谢的主要调节剂。在下丘脑神经元中对 mTOR 复合物 1 (mTORC1) 活性的药理学操作改变了食物摄入和体重。我们之前的研究确定 Rheb1(富含大脑的 Ras 同源物 1)是大脑中 mTORC1 活性的必需激活剂。在这里,我们研究中枢 Rheb1 是否通过 mTORC1 信号调节食物摄入和外周代谢。我们发现,大脑中 Rheb1 的基因缺失会导致 mTORC1 活性降低,并损害正常的食物摄入。结果,Rheb1 敲除小鼠表现出低血糖和脂肪组织中脂质动员增加以及肝脏中的酮生成增加。我们的工作强调了中枢 Rheb1 信号在动物体内的血糖和能量平衡中的重要性。