维生素B12支持雄性小鼠的骨肌氧化酸化能力
Luisa F Castillo1, Katarina E Heyden1, Abigail R Williamson2
1Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
The Journal of nutrition
|January 22, 2026
概括
维生素B12缺乏会损害骨肌肉的线粒体功能,导致线粒体DNA中的 uracil 积累. 补充剂改善了老年小鼠的功能,这表明B12在打击与年龄相关的肌肉衰退方面发挥了作用.
科学领域:
- 线粒体生物学 线粒体生物学
- 营养生物化学 营养生物化学
- 骨肌肉生理学 骨肌肉生理学
背景情况:
- 维生素B12对于叶酸介导的单碳代谢至关重要,对于核酸合成至关重要.
- 维生素B12缺乏可以破坏DNA合成,可能影响线粒体DNA (mtDNA) 完整性.
- 骨肌肉的线粒体功能对于能量生产至关重要,并且可以受到营养的可用性影响.
研究的目的:
- 研究维生素B12可用性对线粒体DNA完整性和骨肌肉功能的影响.
- 在年轻成年小鼠中模拟维生素B12缺乏并评估其影响.
- 评估维生素B12补充剂在减轻与年龄相关的骨肌肉衰退中的作用.
主要方法:
- 年轻的成年小鼠与 metionin synthase knockdown 或野生类型的 littermates 被食控制或维生素B12 缺乏的饮食.
- 年老的小鼠接受了肌肉内注射维生素B12或盐水对照.
- 关键结果包括最大的氧气消耗率,mtDNA中的 uracil 含量,mtDNA拷贝数和线粒体质量.
主要成果:
- 维生素B12缺乏会降低骨肌肉线粒体中的最大呼吸能力和复合I活性.
- 在B12缺乏饮食的小鼠中观察到mtDNA中的 uracil 含量显著增加 ~ 10 倍.
- 在老年小鼠中,维生素B12补充剂增强了胃肌中复杂的IV活性.
结论:
- 维生素B12缺乏会影响骨肌肉的线粒体氧化能力和mtDNA完整性.
- 补充维生素B12对与年龄相关的骨肌肉线粒体功能下降有潜在的益处.
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