Investigating the mechanism of TNFalpha mediated cell death in oligodendrocytes

研究 TNFα 介导的少突胶质细胞死亡机制

基本信息

批准号：
8729514
负责人：
JUNYING YUAN
金额：
$ 36.71万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-15 至 2018-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8729514
关键词：
Age Animal Model Apoptosis Axon B-Cell Activation Biochemical Caspase Cell Communication Cell Death Cells Cessation of life Chemicals Chronic Complex Cuprizone Death Domain Demyelinations Development Experimental Autoimmune Encephalomyelitis Family Figs - dietary Gene Mutation Genetic Genetic Models Goals In Vitro Inflammation Inflammatory Lead MAP3K7 gene MAP3K7IP1 gene Maintenance Manuscripts Mediating Mediator of activation protein Metabolic Metabolism Modeling Molecular Multiple Sclerosis Mus Mutant Strains Mice Myelin Nature Necrosis Nerve Degeneration Neurodegenerative Disorders Neurologic Neurons Oligodendroglia Oxidation-Reduction Pathway interactions Patients Phosphotransferases Play Protein Kinase RIPK3 gene Recruitment Activity Resistance Role Signal Transduction Stress TNF gene TNFRSF1A gene TRADD gene TRAF2 gene Testing Tryptophan 2,3 Dioxygenase Ubiquitination axonal degeneration base caspase-8 cell type central nervous system demyelinating disorder disability in vivo inhibitor/antagonist kinase inhibitor mouse model prevent programs public health relevance treatment strategy young adult

项目摘要

DESCRIPTION (provided by applicant): The goal of this proposal is to explore the molecular mechanism as to why oligodendrocytes (OGs) prefer necroptosis, a regulated necrotic cell death pathway, as the primary cell death mechanism and the contribution of this pathway to progressive demyelination, inflammation and neurodegeneration in animal models of multiple sclerosis (MS). MS, an inflammatory demyelinating disease of the central nervous system (CNS), is the most common chronic neurodegenerative disease for young adults during their most productive ages. While the immunological basis of MS has been studied extensively, we still know very little about the mechanism that leads to the degeneration of OGs, the myelin producing cells that play a critical role in the maintenance of activity and integrity of neuronal axons. Preventing the death of OGs might be able to inhibit demyelination and axonal degeneration, the major cause of irreversible neurological disability in patients with progressive MS. Activation of TNFR1 by TNFalpha has recently been shown to mediate two alternative cell death pathways: caspase-dependent apoptosis and caspase-independent RIP1 kinase-dependent necroptosis (programmed necrosis). However, for most cell types analyzed so far, necroptosis is only activated when the activation of caspases is inhibited by chemical inhibitors or by genetic mutation. Interestingly, we found that OGs undergo necroptosis upon stimulation by TNFalpha alone which can be effectively blocked by Nec-1 or by RIP3 deficiency. We have shown that 7-Cl-O-necrostatin-1 (7-Cl-O-Nec-1), a highly specific inhibitor of RIP1 kinase, protects against TNFalpha-induced oligodendrocyte death in vitro and two mouse models of MS in vivo [cuprizone model and experimental autoimmune encephalomyelitis model (EAE)]. In addition, RIP3-/- mice are also resistant to cuprizone model and RIP3-/- OGs are protected against TNFalpha. We propose to investigate as to why OGs prefer to use necroptosis as the primary cell death pathway and the role and mechanism of RIP1 kinase in mediating the death of OGs. Specific Aim 1 is to investigate the role and mechanism by which cellular metabolism and redox state control the sensitivity of OGs to TNFalpha. This is to test the hypothesis that the cell- cell interaction regulated high metabolic activity in OGs provides a critical mechanism that controls redox state and the sensitivity of OGs to TNFalpha mediated necroptosis. Specific Aim 2 is to investigate the role of S-nitrosylation in regulating the sensitivity of OGs to TNFalpha induced cell death. This is to test the hypothesis that elevated nitrosylation stress in TNFalpha stimulated OGs leads to the inhibition of caspases and sensitization of OGs to necroptosis. Specific Aim 3 is to examine the involvement of RIP1 kinase in mediating necroptosis of OGs in vivo and in vitro using RIP1 kinase dead knockin mutant mice. Our study may provide a strong rationale for the development of RIP1 kinase inhibitors as an OG protective strategy for the treatment of MS, and an orally available, highly specific and nontoxic RIP1 kinase inhibitor, 7-Cl-O-Nec-1, as a lead compound.

描述（由申请人提供）：本提案的目的是探索为什么少突胶质细胞（OG）更喜欢坏死性凋亡（一种受调节的坏死性细胞死亡途径）作为主要细胞死亡机制的分子机制，以及该途径对进行性脱髓鞘的贡献多发性硬化症 (MS) 动物模型中的炎症和神经退行性变。 MS 是一种中枢神经系统 (CNS) 炎症性脱髓鞘疾病，是年轻人最常见的慢性神经退行性疾病。虽然多发性硬化症的免疫学基础已得到广泛研究，但我们对导致 OG 变性的机制仍然知之甚少，OG 是产生髓磷脂的细胞，在维持神经元轴突的活性和完整性中发挥着关键作用。预防 OG 死亡可能能够抑制脱髓鞘和轴突变性，这是进展性多发性硬化症患者不可逆神经功能障碍的主要原因。最近显示 TNFα 激活 TNFR1 可介导两种替代细胞死亡途径：半胱天冬酶依赖性细胞凋亡和不依赖半胱天冬酶的 RIP1 激酶依赖性坏死性凋亡（程序性坏死）。然而，对于迄今为止分析的大多数细胞类型来说，只有当半胱天冬酶的激活被化学抑制剂或基因突变抑制时，坏死性凋亡才会被激活。有趣的是，我们发现OGs在单独接受TNFα刺激后会发生坏死性凋亡，而Nec-1或RIP3缺陷可以有效阻断这种坏死性凋亡。我们已经证明，7-Cl-O-necrostatin-1 (7-Cl-O-Nec-1) 是一种高度特异性的 RIP1 激酶抑制剂，可在体外防止 TNFα 诱导的少突胶质细胞死亡，并在体内防止两种 MS 小鼠模型[铜宗模型和实验性自身免疫性脑脊髓炎模型(EAE)]。此外，RIP3-/-小鼠也对铜宗模型具有抵抗力，并且RIP3-/- OGs受到TNFα的保护。我们建议研究为什么OGs更喜欢使用坏死性凋亡作为主要的细胞死亡途径，以及RIP1激酶在介导OGs死亡中的作用和机制。具体目标1是研究细胞代谢和氧化还原状态控制OGs对TNFα敏感性的作用和机制。这是为了检验以下假设：细胞间相互作用调节 OG 中的高代谢活性，提供了控制氧化还原状态和 OG 对 TNFα 介导的坏死性凋亡敏感性的关键机制。具体目标 2 是研究 S-亚硝基化在调节 OG 对 TNFα 诱导的细胞死亡的敏感性中的作用。这是为了检验以下假设：TNFα 刺激的 OG 中亚硝基化应激升高会导致半胱天冬酶的抑制以及 OG 对坏死性凋亡的敏感性。具体目标 3 是使用 RIP1 激酶死亡敲入突变小鼠在体内和体外检查 RIP1 激酶在介导 OG 坏死性凋亡中的作用。我们的研究可能为开发 RIP1 激酶抑制剂作为治疗多发性硬化症的 OG 保护策略以及口服、高度特异性和无毒的 RIP1 激酶抑制剂 7-Cl-O-Nec-1 提供强有力的理由。铅化合物。