Identification of molecular mechanisms of ER stress-induced apoptosis

内质网应激诱导细胞凋亡的分子机制鉴定

• 批准号: 13671933
• 负责人: NISHITOH Hideki
• 金额: $ 1.98万
• 依托单位: Tokyo Medical and Dental University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671933/
• 关键词: Apoptosis; Cell death; Neurodegenerative disorders; MAP kinase; ASK1; ER stress

In this research project, we have shown the following three results.1) Apoptosis Signal-regulating Kinase (ASK) 1 is activated in response to various cytotoxic stresses including TNF, Fas and reactive oxygen species (ROS) such as H2O2 and activates c-Jun NH2-terminal Kinase (JNK) and p38. We have shown by deleting ASK1 in mice that TNF- and H2O2-induced sustained activations of JNK and p38 are lost in ASK1-/- embryonic fibroblasts, and that ASK1-/- cells are resistant to TNF- and H2O2-induced apoptosis. TNF-induced apoptosis requires ROS-dependent activation of ASK1-JNK/p38 pathways. Thus, ASK1 is selectively required for TNF- and oxidative stress-induced sustained activations of JNK/p38 and apoptosis. (EMBO Reports, Vol. 2, p222-228 2001)2) A yeast two-hybrid screening identified a serine/threonine protein phosphatase 5 (PP5) as a binding partner of ASK1. PP5 directly dephosphorylated an essential phospho-threonine residue within the kinase domain of ASK1 and thereby inactivated ASK1 … More activity in vitro and in vivo. The interaction between PP5 and ASK1 was induced by H2O2 treatment and was followed by the decrease in ASK1 activity. PP5 inhibited not only H2O2-induced sustained activation of ASK1 but also ASK1-dependent apoptosis. Thus, PP5 appears to act as a physiological inhibitor of ASK1-JNK/p38 pathways by negative feedback. (EMBO Journal, Vol. 20, p6028-6036, 2001)3) Accumulation of misfolded proteins within the ER lumen induces cellular stress and cell death, and ER stress has been implicated in human neurodegenerative disorders. However, the molecular mechanism of ER stress-induced cell death was controversial. We have shown the role of ASK1 in the ER stress signaling. Activated IRE1, ER-resident type I transmembrane serine/threonine protein kinase, recruits TRAF2 and ASK1. In untransfected cells, ASK1 is activated by the ER stressors. By using ASK1-/-cells, ASK1 was shown to be required for the ER stress-induced JNK activation and apoptosis. These results indicate that IRE1-TRAF2-ASK1 axis is essential for the ER stress-induced JNK activation and apoptosis. Furthermore, we have shown the evidence that this ER stress-induced cell death pathway plays a central role in the pathogenesis of neurodegenerative disorders. (Genes & Development Vol. 16, p1345-1355, 2002) Thus, ER stress-mediated ASK1 pathway may be one of the therapuitic targets for diseases. Less

在这个研究项目中，我们展示了以下三个结果。1)凋亡信号调节激酶（Apoptosis signal - regulated Kinase， ASK） 1在各种细胞毒性应激（包括TNF、Fas和活性氧（ROS）如H2O2）下被激活，并激活c-Jun nh2末端激酶（JNK）和p38。我们通过在小鼠中删除ASK1表明，TNF-和h2o2诱导的JNK和p38的持续激活在ASK1-/-胚胎成纤维细胞中丢失，并且ASK1-/-细胞对TNF-和h2o2诱导的凋亡具有抗性。tnf诱导的细胞凋亡需要ros依赖性的ASK1-JNK/p38通路激活。因此，ASK1在TNF-和氧化应激诱导的JNK/p38持续激活和细胞凋亡中是选择性必需的。（EMBO Reports, Vol. 2, p222-228 2001）2)酵母双杂交筛选鉴定出丝氨酸/苏氨酸蛋白磷酸酶5 （PP5）作为ASK1的结合伙伴。PP5直接使ASK1激酶结构域中必需的磷酸苏氨酸残基去磷酸化，从而使ASK1失活。H2O2处理诱导PP5与ASK1相互作用，随后ASK1活性降低。PP5不仅抑制h2o2诱导的ASK1持续激活，还抑制ASK1依赖性细胞凋亡。因此，PP5似乎通过负反馈作为ASK1-JNK/p38通路的生理抑制剂。（EMBO Journal, Vol. 20, p6028-6036, 2001）3)内质网管内错误折叠蛋白的积累诱导细胞应激和细胞死亡，内质网应激与人类神经退行性疾病有关。然而，内质网应激诱导细胞死亡的分子机制一直存在争议。我们已经证明了ASK1在内质网应激信号传导中的作用。激活IRE1， er -驻地I型跨膜丝氨酸/苏氨酸蛋白激酶，招募TRAF2和ASK1。在未转染的细胞中，ASK1被内质网应激源激活。通过使用ASK1-/-细胞，ASK1被证明是内质网应激诱导的JNK激活和凋亡所必需的。这些结果表明IRE1-TRAF2-ASK1轴对内质网应激诱导的JNK激活和凋亡至关重要。此外，我们已经证明这种内质网应激诱导的细胞死亡途径在神经退行性疾病的发病机制中起着核心作用。因此，内质网应激介导的ASK1通路可能是疾病的治疗靶点之一。少

项目成果

Matsuzawa, A. et al.: "Physiological roles of ASK1-mediated signal transduction in oxidative stress-and endo plasmic reticulum stress-induced apoptosis : advanced findings from ASK1 knockout mice"Antioxidants and Redox Signal. 4. 415-425 (2002)

Matsuzawa, A. 等人：“ASK1 介导的信号转导在氧化应激和内质网应激诱导的细胞凋亡中的生理作用：ASK1 敲除小鼠的最新发现”抗氧化剂和氧化还原信号。

Morita, K. et al.: "Negative feedback regulation of ASK1 by protein phophatase 5(PP5) in response to oxidative stress"EMBO J.. 20. 6028-6036 (2001)

Morita, K. 等人：“蛋白磷酸酶 5 (PP5) 响应氧化应激对 ASK1 的负反馈调节”EMBO J.. 20. 6028-6036 (2001)

Jibiki, I. et al: "Apoptosis signal-regulating kinase 1-mediated signaling pathway regulates nitric oxide-induced activator protein-1 activation in human bronchial epithelial cells"Am J Respir Cri Care Med. 167. 856-861 (2002)

Jibiki, I. 等人：“细胞凋亡信号调节激酶 1 介导的信号通路调节人支气管上皮细胞中一氧化氮诱导的激活蛋白 1 的激活”Am J Respir Cri Care Med。

Matsuura, H. et al.: "Phosphorylation-dependent scaffolding role of JSAP1/JIP3 in the ASK1-JNK signaling pathway : a new mode of regulation of the MAP kinase cascade"J. Biol. Chem.. 277. 40703-40709 (2002)

Matsuura, H. 等人：“ASK1-JNK 信号通路中 JSAP1/JIP3 的磷酸化依赖性支架作用：MAP 激酶级联调节的新模式”J.

Inoshita, S. et al.: "Phosphorylation and Inactivation of Mcl-1 by c-Jun N-terminal Kinase (JNK) in response to oxidative stress"J. Biol. Chem.. 277. 43730-43734 (2002)

Inoshita, S. 等人：“c-Jun N 末端激酶 (JNK) 响应氧化应激导致 Mcl-1 磷酸化和失活”J.