ビタミンB12はオスマウスの骨格筋の酸化リン酸化能力をサポートする
bioRxiv : the preprint server for biology
|September 5, 2025
まとめ
ビタミンB12欠乏はミトコンドリアDNAにウラシールが蓄積され,骨格筋の機能を損なう. ビタミンB12を強調した老いたマウスのエネルギー生成を補充
科学分野:
- ミトコンドリア生物学
- 栄養学的生化学
- 分子遺伝学
背景:
- ビタミンB12は,核酸媒介による1炭素代謝 (FOCM) に不可欠であり,核酸合成に影響を与える.
- FOCMの障害は,特にミトコンドリアDNA (mtDNA) に敏感なDNAにウラシルの蓄積につながる.
- ユーラシルのmtDNAにおける機能的影響とB12欠乏が骨格筋に及ぼす影響は十分に理解されていません.
研究 の 目的:
- 機能的および食事的ビタミンB12欠乏が,骨格筋におけるmtDNAの完全性およびミトコンドリア機能にどのように影響するか調査する.
- B12欠乏がウラシール含有量と筋肉組織における酸化リン酸化に与える影響を決定する.
主な方法:
- Mtr+/- マウス (機能的B12欠乏症) とマウスにおけるB12欠乏症の食事を使用した.
- ビタミンB12を老いたマウスに投与
- 評価された筋肉の重量,mtDNAウラシル含量,mtDNA含量,酸化リン酸化複合体容量.
主要な成果:
- Mtr+/- マウスは前筋の最大呼吸能力が低下した.
- B12不足の食事によりmtDNAウラシル濃度 (約10倍) が増加し,赤い骨格筋の複合体I能力が低下した.
- ビタミンB12のサプリメントは老いたマウスの胃内膜の複合体活性を増強した.
結論:
- 食中のビタミンB12欠乏はmtDNAにウラシルの蓄積を誘導し,骨格筋の酸化能力を損なう.
- B12欠乏は,エネルギー密集した組織におけるミトコンドリア機能に影響します.
- ビタミンB12のサプリメントは,特定の筋肉のミトコンドリア機能を回復させることができます.
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