腫瘍死滅因子アルファ誘発性心不全におけるミトコンドリアの異常は,DNA修復活動の障害と関連しています
1Cardiovascular Institute, Center for Biological Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Circulation
|November 14, 2001
まとめ
ミトコンドリアDNA修復活動の低下は,TNF-alpha.を過剰に発現するマウスの心不全に寄与する. これは,TNF-αがミトコンドリア機能障害とDNA変異を通して心臓損傷を媒介する可能性があることを示唆しています.
科学分野:
- 心血管生物学 心血管生物学
- ミトコンドリア医学とは
- 分子心臓病学 分子心臓病学
背景:
- 心臓のミトコンドリアDNA (mtDNA) 変異は,拡張性心筋症候群に関連しています.
- 心臓のmtDNA変異を調節するメカニズムはほとんど不明です.
- 腫瘍死滅因子アルファ (TNF-alpha) の過剰発現がマウスで心不全を引き起こす.
研究 の 目的:
- 心臓のmtDNA修復メカニズム,損傷,ミトコンドリアの構造/機能を調査する.
- 心臓のミトコンドリアの変異におけるTNF-αの役割を明らかにする.
- TNF-α,mtDNA変異,心不全の病原性との関連を明らかにする.
主な方法:
- 評価されたmtDNA修復活動 (mtUDG,塩基切除修復).
- Fpgタンパク質消化とサザンブロットを使用して量化されたmtDNA損傷.
- 電子顕微鏡でミトコンドリアの超構造を調べた.
- 測定されたミトコンドリア機能 (シトクロームc酸化酵素,サッキナート脱水酸化酵素) とATP含有量.
主要な成果:
- TNF1.6マウスハートにおけるmtUDGおよび塩基切除修復活動が大幅に減少した.
- 心臓のmtDNAのFpg敏感部位が増加し,mtDNAの損傷が増加していることを示します.
- 心臓のシトクロームc酸化酵素の活性が著しく低下し,ミトコンドリアの形態が変化した.
- 酸化性リン酸化から糖分解へのシフトが観察された (LDH,ALT,乳酸/ピルバ酸比の増加).
結論:
- 減少したmtDNA修復活動は,mtDNA変異と,TNF-α誘発の心不全におけるミトコンドリア機能障害に関連しています.
- 心臓に対するTNF-αの有害な影響には,ミトコンドリアの構造的および機能的な変化が含まれる可能性があります.
- mtDNA修復欠陥は,TNF-α媒介の心臓病変の重要な要因である可能性があります.
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