PERK-p38 MAPK軸は,Fuchs内皮角膜縮症における内プラズマ網膜ストレス誘発性アポトーシスを誘発する
Takako Onishi1, Taichi Yuasa1, Naoyuki Ueda1
1Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan.
Investigative ophthalmology & visual science
|August 26, 2025
まとめ
p38 MAPKは,エンドプラズマ網膜 (ER) ストレスによるフックス内皮角膜縮症 (FECD) の細胞死の主な媒介である. P38 MAPKを阻害すると,細胞死亡を減少させることで,FECDの治療の可能性を示します.
科学分野:
- 眼科について
- 細胞生物学
- 分子生物学
背景:
- フックス内皮角膜縮症 (FECD) は,角膜内皮細胞死亡を伴う.
- エンドプラズマ網膜 (ER) のストレスが,FECDの病原性に関与している.
- FECDにおけるERストレス誘発細胞死におけるp38ミトゲン活性化タンパク質キナーゼ (MAPK) の役割は完全に理解されていません.
研究 の 目的:
- FECDにおけるERストレス誘発の角膜内皮細胞死におけるp38 MAPKの役割を調査する.
- FECDの潜在的な治療標的としてp38 MAPKを評価する.
主な方法:
- 3つのERストレスモデル:TGF-βを持つFECD患者由来細胞 (iFECD),thapsigarginを持つ正常な角膜内皮細胞 (iHCEC) およびMG-132を持つiHCECを使用した.
- 特定の阻害剤 (SB203580,PH-797804,VX-702) を使ってp38 MAPKの活性を調節した.
- PERK- eIF2α- ATF4- CHOP経路の活性化,p38 MAPKのリン酸化,ミトコンドリア機能,および西側ブロッティング,免疫光,およびフロー細胞測定によるアポトーシスを評価した.
主要な成果:
- すべてのモデルでは,PERK- eIF2αのリン酸化の下流とATF4- CHOP誘導の上流でMAPK活性化が行われた.
- iFECD/ TGF-βおよび他のERストレスモデルにおけるp38 MAPK阻害は,CHOPのアップレギュレーションを防止し,ミトコンドリア機能を保存し,アポトーシスを減少させた.
- 機械的に,PERKのノックダウンはp38 MAPKの活性化を抑制したが,p38 MAPKの抑制はPERKの活性化に影響を与えず,階層的な関係を確立した.
結論:
- p38 MAPKは角膜内皮細胞におけるERストレス誘発アポトーシスの重要な媒介体である.
- p38 MAPKは,適応的およびプロアポプトティック展開タンパク質応答 (UPR) 信号の間の分子スイッチとして作用します.
- p38 MAPK阻害剤は細胞保護効果を示し,FECDの治療の可能性を示唆しています.
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