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

• 批准号: 9084667
• 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
• 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/9084667
• 关键词: Age; Animal Model; Apoptosis; Axon; B-Cell Activation; Biochemical; CASP8 gene; Caspase; Cell Communication; Cell Death; Cells; Cessation of life; Chemicals; Chronic; Complex; Cuprizone; DNA Sequence Alteration; Death Domain; Demyelinations; Development; Experimental Autoimmune Encephalomyelitis; Family; Figs - dietary; Genetic; Genetic Models; Goals; Health; In Vitro; Inflammation; Inflammatory; Knock-in; 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; RIPK1 gene; 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; cell type; central nervous system demyelinating disorder; disability; in vivo; inhibitor/antagonist; kinase inhibitor; mouse model; multiple sclerosis treatment; prevent; programs; young adult

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）：该提案的目的是探讨为什么少突胶质细胞（OGS）更喜欢坏死性的分子机制，这是一种受调控的坏死细胞死亡途径，作为主要细胞死亡机制，以及该途径对渐进型脱虫，炎症，炎症，炎症和神经脱发的贡献，在动物模型中（多种模型）。 MS是一种中枢神经系统（CNS）的炎症性脱髓鞘疾病，是最常见的慢性神经退行性疾病，对年轻人最有生产力。尽管已经对MS的免疫学基础进行了广泛的研究，但我们仍然对导致OGS变性的机制知之甚少，OGS（髓磷脂产生细胞在维持神经元轴突的活性和完整性中起着至关重要的作用）。防止OGS死亡可能能够抑制脱髓鞘和轴突变性，这是进行性MS患者不可逆性神经疾病的主要原因。 TNFalphA对TNFR1的激活最近已显示出介导两个替代细胞死亡途径：caspase依赖性细胞凋亡和caspase非依赖性RIP1激酶依赖性坏死病（程序性坏死）。但是，对于到目前为止分析的大多数细胞类型，仅当化学抑制剂或遗传突变抑制胱天蛋白酶的激活时才激活坏死性。有趣的是，我们发现单独使用TNFALPHA刺激后，OGS可以通过NEC-1或RIP3缺乏症有效地阻断坏死。我们已经表明，RIP1激酶的高度特异性抑制剂（7-CL-O-NECROSTATIN-1（7-CL-O-NEC-1）可以防止TNFALPHA诱导的体外少突胶质细胞死亡和两种MS In Vivo的小鼠模型[Cuprizone模型和实验性自动免疫层状层状型模型（Eaeeeephalymyelisian）]。另外，RIP3 - / - 小鼠对库酮模型具有抗性，RIP3 - / - OGS受到TNFALPHA的保护。我们建议研究为什么OGS更喜欢将坏死作用用作主要细胞死亡途径以及RIP1激酶在介导OGS死亡中的作用和机制。具体目的1是研究细胞代谢和氧化还原状态控制OGS对TNFALPHA的敏感性的作用和机制。这是为了检验以下假设 细胞细胞相互作用调节OGS中的高代谢活性提供了一种关键机制，该机制控制了氧化还原状态和OGS对TNFALPHA介导的坏死性的敏感性。具体目的2是研究S-亚硝基化在调节OGS对TNFALPHA诱导细胞死亡的敏感性中的作用。这是为了检验以下假设：TNFALPHA刺激OGS的亚硝基化应激会导致抑制caspase的抑制和OGS对坏死性的敏化。具体目的3是检查RIP1激酶在体内介导OGS坏死的参与和使用RIP1激酶死敲门蛋白突变小鼠的体外参与。我们的研究可能为RIP1激酶抑制剂的开发提供了有力的理由，作为治疗MS的OG保护策略，以及一种口服，高度特异性和无毒的RIP1激酶抑制剂，7-CL-O-NEC-1作为铅化合物。