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RIPK1のカスパース分裂を防ぐ変異は,自己炎症性疾患を引き起こす
Najoua Lalaoui1,2, Steven E Boyden3, Hirotsugu Oda4
1The Walter and Eliza Hall Institute, Parkville, Victoria, Australia. lalaoui@wehi.edu.au.
Nature
|December 13, 2019
まとめ
RIPK1 (受容体相互作用タンパク質キナーゼ1) のカスパース8分裂は,胚の発達と自己炎症症症候群の予防に不可欠です. この分裂を防ぐ突然変異は,ヒトでは重度の炎症性疾患,マウスでは胚性致死を引き起こす.
科学分野:
- 免疫学
- 分子生物学
- 遺伝学
背景:
- 受容体相互作用タンパク質キナーゼ1 (RIPK1) は,先天的な免疫シグナリングを調節する.
- RIPK1は,カスパース-8の割れによって,翻訳後に変化するが,その役割は不明である.
- カスパース8分裂はRIPK3の活性化と死滅を阻害すると考えられている.
研究 の 目的:
- カスパース媒介のRIPK1分裂の生理学的関連性を調査する.
- 分裂抵抗性RIPK1によって引き起こされる自己炎症症症候群のメカニズムを定義する.
- 胚の発達と炎症性ホメオスタシスにおける RIPK1の分裂の役割を決定する.
主な方法:
- ヒトの細胞系とRIPK1カスパース分裂 (Ripk1D325A) を阻害する変異を持つマウスモデルを生成した.
- 胚の死亡率,全身の炎症,免疫細胞の反応を ミュータントマウスで分析した.
- 変異したマウスの細胞におけるTNF誘発のアポプトーシスとネクロプトーシスに対する感受性の評価
主要な成果:
- RIPK1の分裂を防ぐヒトの変異は,早期発症の周期性発熱とリンパ腺病を引き起こす.
- 分裂に抵抗するRipk1D325A/D325Aマウスは,Casp8とRipk3の損失によって救出された胚の死亡率を示します.
- RIPK1キナーゼの活性低下は胚の死亡を防ぐが,致命的な炎症を引き起こす.
- Ripk1D325A/ D325AおよびRipk1D325A/ +細胞は,RIPK3依存アポトーシスおよびネクロプトーシスに対する過敏性を示しています.
- 異卵性Ripk1D325A/+マウスは炎症的刺激に対して過度に反応する.
結論:
- カスパース媒介のRIPK1分裂は胚の発達に不可欠である.
- RIPK1分裂は死滅と自己炎症症候群の両方を抑制する.
- この分裂は 炎症性ホメオスタシスの維持に不可欠です
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