在缺乏BCKDKDK的小鼠中,运动缺陷的代谢基础
Lingyi Zhu1, Isha Kinjawadekar1, Caleb Prempeh1
1Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
The Journal of nutritional biochemistry
|January 26, 2026
概括
分支链α-氨基酸代谢是由BCKDK调节的. 由于氨基酸运输和信号的改变,Bckdk淘汰赛小鼠在营养压力期间表现出大脑功能受损.
科学领域:
- 生物化学 生物化学
- 神经科学是一个神经科学.
- 代谢调节 代谢调节 代谢调节
背景情况:
- 分支链α-氨基酸 (BCAA) 对于蛋白质合成至关重要.
- 分支链α-基托酸脱酶激酶 (BCKDK) 抑制了BCAA的氧化.
- 之前对Bckdk淘汰赛 (KO) 小鼠的研究表明,大脑中的氨基酸样本发生了变化.
研究的目的:
- 为了调查Bckdk KO小鼠大脑氨基酸概况变化的原因.
- 为了比较营养压力对骨肌肉和大脑的影响,Bckdk KO与野生型 (WT) 小鼠.
- 为了评估BCAA衍生的输送到大脑.
主要方法:
- 对WT和Bckdk KO小鼠骨肌肉和大脑中的运动行为,蛋白质合成和营养信号的比较分析.
- 稳定同位素追踪和质谱成像,以追踪从BCAA到大脑的气输送.
- 评估综合应激反应 (ISR) 激活和特定基因表达 (Atf4,Slc7a5).
主要成果:
- 在蛋白质限制期间,Bckdk KO小鼠表现出正常的抓地力,但运动行为受损 (光束穿越,轮子运行).
- 骨肌肉mTORC1信号对两种基因型的食和禁食都有类似的反应.
- Bckdk KO大脑显示ISR激活,在禁食期间增加Atf4和Slc7a5mRNA,与减少BCAA衍生的融入大脑谷氨酸.
- 尽管总脑谷氨酸没有变化,但Bckdk KO小鼠的血清 [15N]-BCAA丰富度较低.
结论:
- 成年小鼠的构成性BCKDH激活在营养稀缺的情况下限制了BCAA衍生的向大脑的输送.
- 这种限制在大脑中触发了适应性ISR,改变了氨基酸载体.
- 在营养压力期间在Bckdk KO小鼠中观察到的大脑脆弱性为它们的运动表现不佳提供了代谢基础.
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