Role of Transglutaminase 2 in Synucleinopathies

转谷氨酰胺酶 2 在突触核蛋白病中的作用

• 批准号: 10285001
• 负责人: M. Maral Mouradian
• 金额: $ 43.18万
• 依托单位: RBHS-ROBERT WOOD JOHNSON MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10285001
• 关键词: Address; Affect; Amyloid Fibrils; Anatomy; Animal Model; Animals; Attenuated; Behavioral; Biological Models; Brain; Brain Diseases; Brain region; Cells; Cerebrospinal Fluid; Data; Dementia with Lewy Bodies; Disease; Disease Progression; Endopeptidase K; Exhibits; Genes; Genetic; Glutamine; Goals; Guanosine Triphosphate Phosphohydrolases; Human; In Vitro; Injections; Investigation; Knock-out; Knowledge; Lewy Bodies; Lewy neurites; Lysine; Mammalian Cell; Mediating; Modeling; Molecular; Molecular Conformation; Molecular Weight; Motor; Mus; Nature; Nerve Degeneration; Neurons; Outcome; Parkinson Disease; Parkinson' s Dementia; Pathogenicity; Pathologic; Pathologic Processes; Pathology; Patients; Performance; Phenotype; Play; Process; Protein Disulfide Isomerase; Protein-Serine-Threonine Kinases; Proteins; Proteolysis; Resistance; Role; Seeds; Severities; Stress; Study models; Substantia nigra structure; Testing; Therapeutic; Thioflavin S; Transgenic Mice; Transgenic Organisms; Transglutaminases; Wild Type Mouse; Yeasts; alpha synuclein; base; behavioral phenotyping; crosslink; design; dopaminergic neuron; inhibitor/antagonist; mRNA Expression; monomer; mutant; neuroinflammation; phenotypic biomarker; preservation; protein aggregation; protein expression; response; synucleinopathy; transglutaminase 2

Project Summary: α-Synuclein is a key pathogenic protein in Parkinson’s disease (PD) and Dementia with Lewy Bodies (DLB) based on genetic, neuropathologic, cell biologic and animal model studies. This intrinsically disordered protein can oligomerize, misfold, and form fibrils that propagate across neurons in the brain and accumulate in Lewy bodies and Lewy neurites. It is believed that the oligomeric forms of α-synuclein represent the toxic species, and these can nucleate monomers to perpetuate the pathologic process underlying the progressive nature of the disease. Thus, understanding the factors that trigger the initial steps of oligomerization is critical for designing disease modifying therapeutic strategies. A hitherto under-explored factor is molecular cross- linking of α-synuclein by transglutaminase 2 (TG2) between glutamine and lysine residues creating intermolecular isopeptide bonds that are highly resistant to proteolysis. Several lines of evidence indicate that TG2 cross-links α-synuclein leading to its aggregation in vitro, in cultured mammalian cells, in yeast cells, and in the brains of transgenic mice. We have found that the phenotype of α-synuclein transgenic mice is exacerbated by over-expressing TG2 and is mitigated by knocking it out. Studies in patients with α-synucleinopathy also corroborate the hypothesis that TG2 plays a pathogenetic role. TG2 expression is increased in the substantia nigra and cerebrospinal fluid of PD patients compared with control subjects, TG2 co-localizes with α-synuclein aggregates in stressed dopaminergic neurons in PD brains, and TG2-catalyzed cross-links co-localize with α-synuclein in Lewy bodies in PD and DLB affected brains. Despite this body of evidence, it remains unknown whether TG2-mediated cross-linking of α-synuclein promotes the propagation of these aggregates across the brain. We hypothesize that it does and propose to test this hypothesis through two specific aims: 1) Investigate if the presence of TG2 and its expression level influence the propagation of α-synuclein fibrils, and 2) Examine if the transglutaminase enzymatic activity of TG2 is responsible for this process. Knowledge gained from these studies will address a fundamental scientific question about the pathogenetic mechanism of TG2-mediated α-synuclein propagation and aid in developing targeted disease modifying therapeutic for synucleinopathies.

项目摘要： α-Synuclein是帕金森病（PD）和路易痴呆（Dementia with Lewy）的重要致病蛋白 基于遗传学、神经病理学、细胞生物学和动物模型研究的DLB。这 内在无序的蛋白质可以寡聚、错误折叠并形成纤维， 脑内的神经元，并积累在路易体和路易神经突。据信 α-突触核蛋白的寡聚体形式代表毒性物质，它们可以使单体成核 使疾病进行性的病理过程永久化。因此，在本发明中， 了解引发低聚反应初始步骤的因素对于设计 改变疾病的治疗策略。一个迄今为止未被探索的因素是分子交叉- 通过谷氨酰胺和赖氨酸残基之间的转氨酶2（TG 2）连接α-突触核蛋白 产生高度抗蛋白水解的分子间异肽键。几行 有证据表明，TG 2交联α-突触核蛋白，导致其在体外聚集，在培养的 哺乳动物细胞、酵母细胞和转基因小鼠的大脑中。我们发现 α-突触核蛋白转基因小鼠的表型因过度表达TG 2而恶化， 把它打晕就能减轻痛苦对α-突触核蛋白病患者的研究也证实了 假设TG 2起致病作用。TG 2在黑质中表达增加， 与对照受试者相比，PD患者的黑质和脑脊液中，TG 2与 PD脑中应激多巴胺能神经元中的α-突触核蛋白聚集体，以及TG 2催化的 交联与α-突触核蛋白共定位在PD和DLB影响的脑中的路易体中。尽管 这一证据体，它仍然是未知的，是否TG 2介导的交联的α-突触核蛋白 促进了这些聚集体在大脑中的传播。我们假设它是， 我建议通过两个具体目标来检验这一假设：1）调查TG 2的存在是否 和其表达水平影响α-突触核蛋白原纤维的增殖，和2）检查 TG 2的转氨酶酶活性负责该过程。获得的知识 从这些研究将解决一个基本的科学问题， TG 2介导的α-突触核蛋白增殖和辅助靶向疾病发展的机制 用于突触核蛋白病的改良治疗剂。