Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States.
Vanderbilt University School of Medicine, Nashville, TN, United States.
Mol Metab. 2014 Feb 19;3(4):394-407. doi: 10.1016/j.molmet.2014.01.014. eCollection 2014 Jul.
Insulin signaling in the central nervous system (CNS) regulates energy balance and peripheral glucose homeostasis. Rictor is a key regulatory/structural subunit of the mTORC2 complex and is required for hydrophobic motif site phosphorylation of Akt at serine 473. To examine the contribution of neuronal Rictor/mTORC2 signaling to CNS regulation of energy and glucose homeostasis, we utilized Cre-LoxP technology to generate mice lacking Rictor in all neurons, or in either POMC or AgRP expressing neurons. Rictor deletion in all neurons led to increased fat mass and adiposity, glucose intolerance and behavioral leptin resistance. Disrupting Rictor in POMC neurons also caused obesity and hyperphagia, fasting hyperglycemia and pronounced glucose intolerance. AgRP neuron specific deletion did not impact energy balance but led to mild glucose intolerance. Collectively, we show that Rictor/mTORC2 signaling, especially in POMC-expressing neurons, is important for central regulation of energy and glucose homeostasis.
中枢神经系统 (CNS) 中的胰岛素信号调节能量平衡和外周葡萄糖稳态。Rictor 是 mTORC2 复合物的关键调节/结构亚基,是 Akt 丝氨酸 473 位点磷酸化所必需的。为了研究神经元 Rictor/mTORC2 信号对 CNS 能量和葡萄糖稳态的调节作用,我们利用 Cre-LoxP 技术生成了所有神经元中缺乏 Rictor 的小鼠,或在 POMC 或 AgRP 表达神经元中缺乏 Rictor 的小鼠。所有神经元中 Rictor 的缺失导致脂肪量和肥胖增加、葡萄糖耐量受损和行为性瘦素抵抗。破坏 POMC 神经元中的 Rictor 也会导致肥胖和过度进食、空腹高血糖和明显的葡萄糖耐量受损。AgRP 神经元特异性缺失不会影响能量平衡,但会导致轻度葡萄糖耐量受损。总之,我们表明 Rictor/mTORC2 信号,特别是在 POMC 表达神经元中,对于中枢神经系统对能量和葡萄糖稳态的调节非常重要。