ミトコンドリアのNa+/Ca2+交換器は,Ca2+のホメオスタシスと生存に不可欠である
Timothy S Luongo1, Jonathan P Lambert1, Polina Gross2
1Center for Translational Medicine, Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
Nature
|April 27, 2017
まとめ
ミトコンドリアのカルシウムエクスポーターNCLX (Slc8b1) をマウスハートで削除すると,重度の心不全と突然死が起こりました. 心臓の損傷から保護されたNCLX機能を回復し,心臓の健康における重要な役割を強調します.
科学分野:
- 心血管生物学
- ミトコンドリア生理学
- 細胞 死 の 仕組み
背景:
- ミトコンドリアカルシウム (mCa2+) は細胞代謝と死亡シグナルに不可欠ですが,心臓の恒常性および疾患における正確な役割は議論の余地があります.
- Slc8b1によってコードされたミトコンドリアのナトリウム-カルシウム交換器 (NCLX) は,心臓細胞のミトコンドリアからカルシウムを挤出する主要な候補である.
研究 の 目的:
- 心臓機能の維持と心不全の予防におけるNCLXの重要な役割を調査する.
- 心血管疾患におけるミトコンドリアカルシウムレベルを調節する治療の可能性を調査する.
主な方法:
- 成人マウスの心臓におけるSlc8b1遺伝子のタモキシフェン誘発の消去.
- 条件付きの心臓特異的なNCLX過剰発現は,トランスジェニックマウスを使用しています.
- 心臓機能,細胞死経路,ミトコンドリアカルシウムレベルの評価
- 缺血再注射による損傷に対する保護の評価
主要な成果:
- Slc8b1の消去は14日以内にマウスの87%以上で突然死をもたらし,重度の心筋機能不全と心不全が特徴でした.
- 心臓病理はミトコンドリアのカルシウム過負荷,超酸化物産生の増加,死滅性細胞死によって引き起こされた.
- ミトコンドリアの透過性の 遺伝的抑制が 心臓病理を救った
- NCLXの過剰発現はミトコンドリアのカルシウムクリアランスを改善し,ミトコンドリアの透過性の移行を防止し,不血症による心不全から保護しました.
結論:
- NCLX経由のミトコンドリアカルシウム流出は,心臓の恒常性を維持し,心不全を予防するために不可欠です.
- NCLXを標的にしたり,ミトコンドリアのカルシウム流出を強めたりすることは,心血管疾患の治療戦略として有望です.
- ミトコンドリアのカルシウム過負荷は 衰弱した心臓の 病理学的プロセスの主要な原動力です
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