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：
8620945
负责人：
JUNYING YUAN
金额：
$ 37.08万
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/8620945
关键词：
Age Animal Model Apoptosis Axon 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

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 TNF¿ 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 TNF¿ 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 TNF¿-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 TNF¿. 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 TNF¿. 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 TNF¿ mediated necroptosis. Specific Aim 2 is to investigate the role of S- nitrosylation in regulating the sensitivity of OGs to TNF¿ induced cell death. This is to test the hypothesis that elevated nitrosylation stress in TNF¿ 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.

该提案的目标是探索少突胶质细胞（OG）更喜欢的分子机制坏死性凋亡，一种受调节的坏死性细胞死亡途径，作为主要的细胞死亡机制及其贡献在动物模型中，这种途径导致进行性脱髓鞘、炎症和神经变性多发性硬化症 (MS) 是一种中枢神经系统 (CNS) 炎症性脱髓鞘疾病。年轻人在最有生产力的年龄段最常见的慢性神经退行性疾病。虽然人们主要研究了多发性硬化症的免疫学基础，但我们对多发性硬化症的免疫学基础仍然知之甚少。导致 OG 退化的机制，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可能能够抑制 OG 的死亡。脱髓鞘和轴突变性是患者不可逆神经功能障碍的主要原因进行性多发性硬化症。 TNF 激活 TNFR1？最近被证明可以介导两种替代的细胞死亡途径： caspase 依赖性细胞凋亡和 caspase 独立性 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，坏死性凋亡仅在激活时才被激活。半胱天冬酶受到化学抑制剂或基因突变的抑制。 TNF刺激后坏死性凋亡¿单独使用可被 Nec-1 或 RIP3 缺陷有效阻断。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，可保护对抗TNF?? -体外诱导少突胶质细胞死亡和两种体内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-/-小鼠也具有抵抗力。铜宗模型和 RIP3-/- OG 具有抗 TNF 的保护？我们建议调查 OG 的原因。更倾向于以程序性坏死作为主要的细胞死亡途径以及RIP1激酶在细胞凋亡中的作用和机制介导 OG 死亡的具体目标 1 是研究细胞死亡的作用和机制。代谢和氧化还原状态控制 OG 对 TNF 的敏感性¿ .这是为了检验细胞的假设- 细胞相互作用调节 OG 中的高代谢活性提供了控制氧化还原状态的关键机制以及 OG 对 TNF 的敏感性¿具体目标 2 是研究 S- 介导的坏死性凋亡。亚硝基化调节 OG 对 TNF 的敏感性¿这是为了检验以下假设： TNF 中亚硝基化应激升高¿受刺激的 OG 会导致半胱天冬酶的抑制和 OGs 到坏死性凋亡的具体目标 3 是检查 RIP1 激酶在介导坏死性凋亡中的作用。 OGs在体内和体外使用RIP1激酶死亡敲入突变小鼠的研究可能提供强有力的证据。开发 RIP1 激酶抑制剂作为治疗 MS 的 OG 保护策略的基本原理，以及一种口服、高度特异性且无毒的 RIP1 激酶抑制剂 7-Cl-O-Nec-1，作为先导化合物。