分支链氨基酸代谢缺陷通过激活mTOR信号来促进α细胞的增殖
Yulin Yang1, Shushu Wang1, Chunxiang Sheng1
1Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
在胰腺α细胞中缺陷的分支链氨基酸 (BCAA) 分解通过mTOR信号增加了它们的增殖. 这不会影响葡萄糖分泌或整体葡萄糖平衡.
科学领域:
- 代谢调节 代谢调节 代谢调节
- 内分泌学 在内分泌学.
- 细胞生物学 细胞生物学
背景情况:
- 循环中分支链氨基酸 (BCAA) 的升高与2型糖尿病有关.
- 在葡萄糖平衡中BCAA代谢的功能尚未完全理解.
- 胰腺α细胞作为关键的氨基酸传感器.
研究的目的:
- 为了研究胰腺α细胞内BCAA代谢对全身能量代谢的影响.
- 阐明BCAA催化作用影响α细胞功能和增殖的机制.
主要方法:
- 产生特定于α细胞的分支链α-酸脱酶E1α子单元 (BCKDHA) 淘汰赛 (BCKDHA-αKO) 小鼠.
- 评估体重,脂肪,能量消耗,血葡萄糖和葡萄糖代谢.
- 在体外研究中,使用aTC1-6细胞治疗了BCAA,BT2和Rapamycin.
- 对细胞增殖和mTOR信号通路激活 (S6酸化) 的分析.
主要成果:
- BCKDHA-αKO小鼠表现出正常的体重,脂肪,能量消耗,葡萄糖水平和葡萄糖代谢.
- 阿尔法细胞中BCKDHA的删除导致了阿尔法细胞的增多,特别是在新生小鼠中.
- 氨酸在体外促进了aTC1-6细胞的增殖,这种效应被BT2和Rapamycin抑制.
- 在aTC1-6细胞中BT2和拉帕素减弱的白素刺激的S6酸化,反映了BCKDHA-αKO小鼠的观察.
结论:
- 胰腺α细胞中BCAA代谢受损导致白蛋白的积累,通过mTOR信号通路促进α细胞的增殖.
- 尽管阿尔法细胞增多,但葡萄糖分和全身葡萄糖平衡仍然不受影响.
- 阿尔法细胞的BCAA代谢在调节阿尔法细胞质量方面起作用,但不是急性葡萄糖控制.
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