慢性多関節炎は,マクロファージの分解から脱出する哺乳類のDNAによって引き起こされる
Kohki Kawane1, Mayumi Ohtani, Keiko Miwa
1Department of Genetics, Osaka University, Osaka 565-0871, Japan.
Nature
|October 27, 2006
まとめ
DNase IIが欠けているマウスは,DNAが分解されていないために慢性多関節炎を発症します. これは腫瘍死滅因子アルファ (TNF-alpha) の生成を誘発し,関節炎やリウマチ性関節炎のような症状を引き起こす.
科学分野:
- 免疫学 免疫学とは
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- 染色体DNAの分解は,プログラム細胞死とエリトロポエシスにおいて不可欠である.
- DNase IIは,アポプトティック細胞とマクロファージに囲まれた赤色素原体前駆体内のDNAを消化する鍵となる酵素です.
研究 の 目的:
- 自己免疫疾患の予防におけるDNase IIの役割を調査する.
- DNase II欠乏が慢性多関節炎を引き起こすメカニズムを解明する.
主な方法:
- DNase IIノックアウト (DNase II-/-) と条件付きノックアウトマウスの生成と分析.
- 炎症マーカー,自己抗体,および影響を受けた関節におけるサイトカイン遺伝子発現の評価.
- 抗腫瘍死滅因子アルファ (TNF-alpha) 抗体治療の治療効果の評価.
主要な成果:
- DNase II-/- マウスは,ヒトのリウマチ性関節炎に類似した慢性多関節炎を発症した.
- 活性化されたサイトカイン遺伝子と,抗循環性シトルリン化ペプチド抗体,リウマトイド因子,マトリックスメタルプロテインアゼ-3のレベルの上昇は,関節および血清で観察されました.
- 骨髄におけるTNF-αのアップレギュレーションが関節炎発症に先行し,抗TNF-alpha抗体の投与が疾患を予防した.
結論:
- DNase II欠乏症によるマクロファージによるDNA分解の障害は,TNF-αの生成につながります.
- TNF-αはシノビア細胞を活性化し,サイトカインの産生を誘発し,慢性多関節炎を引き起こす.
- DNase IIは,自己免疫性関節炎を予防する上で重要な役割を果たします.
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