固有のアポトーシス経路は,C. elegansにおけるミトコンドリアのROSに対するプロロングライフ応答を媒介する
Callista Yee1, Wen Yang1, Siegfried Hekimi1
1Department of Biology, McGill University, Montreal, QC H3A 1B1, Canada.
Cell
|May 13, 2014
まとめ
ミトコンドリアのROSシグナル伝達は,アポトーシス経路を活性化することによって,C. elegansの寿命を延ばし,細胞死を誘発するのではなく,保護性遺伝子発現を誘発し,ストレス下での生存を促進します.
科学分野:
- 細胞生物学 細胞生物学
- 老化に関する研究.
- ミトコンドリアの機能
背景:
- C. elegansの電子伝送連鎖変異体における長寿の増加は,ミトコンドリアの活性酸素種 (mtROS) 信号伝達と関連している.
- 本質的なアポトーシス経路は,ストレスや損傷に対する細胞の反応に関与する保存されたメカニズムです.
研究 の 目的:
- C. elegansの電子輸送鎖変異体の長寿を媒介するシグナル伝達経路を解明する.
- 増加したmtROSに対する反応として,内在的なアポトーシス経路の役割を調査する.
- アポトーシス経路を通じたmtROSシグナル伝達が,アポトーシスとは独立して生存を促進できるかどうかを判断する.
主な方法:
- 長寿とmtROSシグナル伝達を研究するために,C.elegans電子輸送鎖変異体 (isp-1とnuo-6) を利用しました.
- 本質的なアポトーシス経路のコンポーネント (CED-9/Bcl2,CED-4/Apaf1,CED-3/Casp9) とCED-13の関与を調査した.
- 遺伝子の発現パターンを分析し,mtROSの上昇に反応した.
主要な成果:
- 長生きしたC. elegans変異体におけるmtROS信号は,CED-13を含む固有アポトーシス経路によって伝達される.
- mtROSによるこの経路の活性化は,アポトーシスを誘発するのではなく,ユニークな遺伝子発現パターンを誘発します.
- この遺伝子発現の調節は,ストレス耐性を高め,生物の生存を促進し,長寿につながります.
結論:
- アポプトシス経路によるmtROSの検知は,アポプトシスとは独立して保護メカニズムを誘発することができます.
- このアポプトシス経路の非アポプトシス機能は,mtROSが上昇した条件下での長寿に寄与する.
- ミトコンドリア,ROS,アポトーシス,そして老化との複雑な関係を明らかにした.
関連する概念動画
The Intrinsic Apoptotic Pathway
6.2K
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...
6.2K
The Extrinsic Apoptotic Pathway
6.2K
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...
6.2K
Apoptosis
12.0K
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...
12.0K
Caspases
8.7K
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...
8.7K
Mitochondria
13.4K
Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
13.4K
Electron Transport Chain: Complex I and II
11.9K
The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
ROS generation is regulated and maintained at moderate levels necessary...
11.9K


