カルシウムセンサー受容体は,Ca2+とcAMPを通じてNLRP3炎症体を調節する
Geun-Shik Lee1, Naeha Subramanian, Andrew I Kim
1Inflammatory Disease Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Nature
|November 13, 2012
まとめ
カルシウム感知受容体 (CASR) は,カルシウム (Ca2+) と周期性AMP (cAMP) 信号伝達を介してNLRP3炎症体を活性化します. CASR機能障害は,CAPSのような自己炎症性疾患に寄与する.
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:
- クリオピリン関連周期性症候群 (CAPS) は,NLRP3遺伝子の変異によって引き起こされる自己炎症性疾患です.
- NLRP3炎症ゾームの活性化は,インタールイキン-1β (IL-1β) の成熟に不可欠ですが,その正確なメカニズムは不明です.
- NLRP3の活性化に関する既存のモデルには,K+流出,活性酸素種,およびリソソームの不安定化が含まれています.
研究 の 目的:
- NLRP3炎症体活性化の分子メカニズムを解明する.
- CAPSに関連した突然変異がNLRP3.3を活性化する方法を理解する.
- NLRP3炎症体活性化の主要な分子調節体を特定する.
主な方法:
- ネズミのモデルを使用してNLRP3炎症体の活性化におけるカルシウム感受受体 (CASR) の役割を調査しました.
- CASRのノックダウンを使用して,炎症体の活性化に必要性を評価しました.
- 細胞内Ca2+と循環型AMP (cAMP) のレベルがNLRP3炎症体集合と活性に及ぼす影響を調べました.
- 野生型および変異性NLRP3.3に対するcAMPの結合親和性を評価した.
主要な成果:
- CASRの活性化は,細胞内Ca2+の増加とcAMPの減少を通じてNLRP3炎症体の活性化につながります.
- CASRアゴニストは,外因的なATPとは独立してNLRP3炎症体を活性化させます.
- CASRのノックダウンは,既知のNLRP3活性化剤による炎症体の活性化を減少させます.
- 細胞質Ca2+の増加は炎症体の組み立てを促進し,CAPSに関連した自発的なNLRP3活性には必要である.
- 減少したcAMPレベルは,NLRP3への抑制結合を緩和することによって,NLRP3炎症体を独立して活性化します.
- CAPSに関連した変異性NLRP3は,cAMP結合親和性が低く,制御不能のIL-1β生成につながります.
結論:
- Ca2+とcAMPは,NLRP3炎症体の重要な分子調節体である.
- CASRシグナリングはNLRP3炎症ゾームの活性化に重要な役割を果たします.
- Ca2+とcAMPのシグナリングの調節不良は,CAPSの病原化に寄与する.
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