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Updated: Jun 21, 2026

07:42
Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
Published on: June 29, 2011
XIAPは,タイプIとタイプIIのFAS誘発アポトシスを区別する
Philipp J Jost1, Stephanie Grabow, Daniel Gray
1The Walter and Eliza Hall Institute of Medical Research, Melbourne University, Parkville, Victoria 3050, Australia.
Nature
|July 24, 2009
まとめ
XIAP (X染色体関連アポトーシス阻害タンパク質) 機能の喪失により,肝臓とベータ細胞はBIDなしでアポトーシスを引き起こす. これは,XIAPがアポトーシスシグナル差異の鍵であることを明らかにし,肝臓患者のIAP阻害剤の使用に注意を促します.
科学分野:
- 細胞生物学 細胞生物学
- アポプトシスの分子メカニズム
- 免疫学 免疫学とは
背景:
- FAS (APO-1/CD95) とFASLは,望ましくない細胞を排除し,自己免疫と癌を予防するために不可欠です.
- アポプトーシス経路は細胞タイプによって異なります:タイプI細胞 (リンパ球など) は直接エフェクタカスペスを活性化しますが,タイプII細胞 (肝細胞など) はBID経由で増幅する必要があります.
- XIAP (X染色体関連アポトーシスタンパク質阻害剤) はアポトーシスの重要な調節剤である.
研究 の 目的:
- タイプIとタイプIIの細胞間のFAS誘発のアポトーシスを区別するXIAPの役割を調査する.
- XIAPの阻害によって,II型細胞のアポトーシスメカニズムが変化するかどうかを判断する.
主な方法:
- マウスの遺伝子ターゲティングにより,XIAPの機能が妨げられる.
- XIAPを阻害するSMAC (DIABLO) 模倣薬の投与.
- 肝細胞と臓のβ細胞におけるFAS誘発のアポトーシスの分析.
主要な成果:
- 遺伝子ターゲティングまたはSMAC模倣薬によるXIAP機能の喪失は,FAS誘発性アポトーシスのBIDから独立した肝細胞とベータ細胞 (タイプII) を生み出します.
- XIAPは,タイプIとタイプIIのアポトーシスシグナル伝達経路を区別する重要な要因として特定されました.
- ヘパトサイトとベータ細胞は,通常タイプIIで,XIAPの抑制によりタイプI型のアポトーシスを示した.
結論:
- XIAPは,タイプIとタイプIIのアポトーシスシグナリングの間の重要な差別因子です.
- IAPの阻害剤 (SMAC模倣剤など) は,アポトーシスを変化させ,特に肝臓疾患の癌患者の場合,注意を払う必要があります.
- XIAPの役割を理解することは,標的がん治療の開発と潜在的な副作用の管理に不可欠です.
関連する概念動画
The Extrinsic Apoptotic Pathway
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
The Intrinsic Apoptotic Pathway
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
Caspases
Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
Apoptosis
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.
Cellular Injury V: Apoptosis and Autophagy
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...

