LPSによるTNF-α誘導は,TPL2/ERK依存の経路を通じて,ポストトランスクリプションで調節される
C D Dumitru1, J D Ceci, C Tsatsanis
1Kimmel Cancer Center, Department of Microbiology and Immunology, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107, USA.
Cell
|February 13, 2001
まとめ
Tpl2のノックアウトマウスは,腫瘍死滅因子アルファ (TNF-alpha) の産生が低下し,病理学に対する抵抗性を示した. Tpl2シグナリングは,特にTNF-α mRNA輸送を促進し,その誘導に影響を与えます.
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.
- 細胞シグナル伝達 細胞信号伝達
背景:
- 腫瘍死滅因子アルファ (TNF-alpha) は,免疫反応と炎症における重要なサイトカインです.
- Tpl2は,様々な細胞信号伝達経路に関与するキナーゼですが,TNF-αの調節における正確な役割は完全に理解されていません.
研究 の 目的:
- リポポリサッカリド (LPS) 誘発のTNF-α生成および関連するシグナル伝達経路におけるTPl2の役割を調査する.
- Tpl2がTNF-α mRNAの発現と局所化に影響を与える分子メカニズムを解明する.
主な方法:
- 比較分析のためにTpl2ノックアウトマウスと野生型の littermatesを使用しました.
- LPSでペリトネアルマクロファージを刺激し,サイトカインの産生とMAPK経路の活性化を評価した.
- TNF-α誘導におけるERK1/2の役割を調べるために,MEK阻害剤PD98059を使用しました.
- TNF-α mRNAにおけるAUに富んだ元素の消去の影響を調査した.
- TNF-α mRNAの局所化を追跡するためにサブセルラー分断を行いました.
主要な成果:
- Tpl2ノックアウトマウスは,LPS曝露時にTNF-α濃度が著しく低下し,LPS/D-ガラクトサミン誘発病理学に耐性を示した.
- Tpl2欠乏マクロファージにおけるLPS刺激は,MEK1,ERK1,ERK2を活性化することができなかったが,JNK,p38 MAPK,NF-kappaBは活性化していた.
- 正常なマクロファージにおけるMEK1/2の抑制は,TPL2ノックアウト細胞で観察されたTNF-α誘導欠陥を模倣した.
- TNF-α mRNAにおけるAU豊富なモチーフの変異により,Tpl2欠乏が誘導に与える影響が軽減された.
- Tpl2シグナリングは,TNF-α mRNAの核から細胞質への輸送を特異的に強化することが判明しました.
結論:
- Tpl2は,主にMEK/ERK経路の活性化を調節することによって,LPS誘発のTNF-α生成において重要な役割を果たします.
- Tpl2のキナーゼ活動は,TNF-α mRNAの核から細胞質への効率的な輸送に不可欠であり,それによってその翻訳と誘導を制御します.
- これらの発見は,TNF-α mRNAダイナミクスの調節を通じて,Tpl2を炎症反応の重要な調節体として強調しています.
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