母親のX染色体は,雌マウスの認知能力と脳の老化に影響する
Samira Abdulai-Saiku1, Shweta Gupta1, Dan Wang1
1Department of Neurology, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA.
Nature
|January 22, 2025
まとめ
母親のX染色体 (Xm) が活性化すると,認知機能が低下し,雌マウスの脳の老化が加速する. 静止されたXm遺伝子の活性化により 認知機能が改善され 老齢期の女性における認知機能低下の治療目標が示唆された.
科学分野:
- 神経科学
- 遺伝学
- 老化に関する研究
背景:
- 雌性哺乳類は2つのX染色体 (Xm,Xp) を有し,そのうちの1つが発達中に不活性化され,X染色体の可変性が生じます.
- X染色体の起源による表遺伝的変異は,健康と病気に影響を与えるが,機能的な影響は不明である.
- X染色体モザイク主義を理解することは,女性の認知の多様性を説明する上で極めて重要です.
研究 の 目的:
- X染色体の歪み,特に母性X染色体 (Xm) が脳機能と老化に及ぼす機能的影響を調査する.
- 活性Xmと活性父性X染色体 (Xp) に関連したユニークな神経特性を特定する.
主な方法:
- X染色体不活性化度が異なる雌マウスの比較分析 (Xm対Xp活性).
- 生涯を通じて認知機能と海馬の老化マーカーの評価
- DNAメチル化と遺伝子インプリントを含む,海馬の神経細胞の表遺伝子分析.
- CRISPR媒介の遺伝子活性化により 特定のインプリントされた遺伝子が 認知に与える影響を検証します
主要な成果:
- 活性Xm染色体は 生涯にわたって雌マウスの認知機能を損なっており,年齢とともに悪化する.
- Xmバイアスがヒポカンプスの生物学的および表遺伝的老化を加速した.
- いくつかの認知に関連する遺伝子は,海馬の神経細胞のXm染色体にインプリントされていることが判明しました.
- このインプリントされたXm遺伝子を活性化することで 老齢のメスのマウスの認知機能が改善されました
結論:
- 母親のX染色体 (Xm) は認知機能に悪影響を及ぼし,女性の脳の老化を加速させる可能性があります.
- Xm染色体への遺伝子インプリントは 認知に関連した遺伝子を沈黙させ 年齢に伴う認知の衰退に寄与します
- Xmインプリントされた遺伝子をターゲットにすることで 女性の認知機能の欠陥や 脳老化を緩和する 治療戦略が生まれます
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