The Role of Polyamines in the Neuropathology of Tuberous Sclerosis Complex

多胺在结节性硬化症神经病理学中的作用

基本信息

批准号：
9436149
负责人：
MICHAEL J GAMBELLO
金额：
$ 23.4万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-30 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9436149
关键词：
Address Adverse effects Affect Anabolism Attenuated Autistic Disorder Binding Proteins Biochemical Biological Assay Birth Brain Cations Cell Proliferation Cell Survival Clinical Trials Collaborations Communities Complex Control Animal DL-alpha-Difluoromethylornithine Data Development Developmental Disabilities Dimerization Disease Doctor of Philosophy Embryo Ensure Enzymes Epilepsy Event FRAP1 gene Foundations Future Gene Expression Genetic Half-Life Hereditary Disease Heterodimerization Hippocampus (Brain)Histologic Histology Immunosuppression Intraperitoneal Injections Knowledge Laboratories Metabolism Mitotic Cell Cycle Molecular Mus Mutation Neurologic Symptoms Neuropathogenesis Ornithine Decarboxylase Ornithine Decarboxylase Inhibitor Pathogenesis Pathology Pathway interactions Patients Pharmacology Phenotype Phosphotransferases Polyamines Protein Biosynthesis Proteins Publishing Putrescine Radial Reaction Research Role Signal Pathway Signal Transduction Signaling Protein Sirolimus Spermidine Spermine Subependymal Giant Cell Astrocytoma TSC1 gene TSC2 gene Testing Therapeutic Tissues Translating Translation Initiation Tuberous sclerosis protein complex Up-Regulation Weaning Weight Work activity marker dimer inhibitor/antagonist metabolomics mouse model mutant neurological pathology neuropathology neuropsychiatric disorder new therapeutic target novel novel therapeutics postnatal precursor cell prenatal response targeted treatment

项目摘要

Project Summary Tuberous sclerosis complex (TSC) is a genetic disorder that often causes neurologic pathology such as epilepsy, developmental disability, or neuropsychiatric disease. TSC is caused by heterozygous, inactivating mutations in the TSC1 or TSC2 genes that encode protein binding partners hamartin and tuberin. Dimerized hamartin and tuberin negatively regulate mTORC1, the mechanistic target of rapamycin complex 1. In response to anabolic signals, activated mTORC1 stimulates protein synthesis, cell growth and cell cycle progression. The pathogenesis of TSC is largely due to constitutive mTORC1 activation and consequent cellular anabolism. Despite advances in our knowledge about the molecular basis of TSC, the downstream events causing TSC pathology remain unclear. Using an unbiased, global metabolomic profiling approach, we assayed hippocampal tissue from a well-characterized mouse model of TSC in which the Tsc2 gene is conditionally disrupted in radial glial precursor cells (Tsc2-RG). These and subsequent data revealed an upregulation of the polyamine putrescine and increase in ornithine decarboxylase (ODC) activity, the rate limiting enzyme in polyamine synthesis, in Tsc2-RG mutants. Polyamines are essential for cell proliferation and survival and evidence suggests an interaction between polyamines and mTORC signaling. In this proposal, we will determine if directly reducing ODC activity ameliorates TSC-associated neuropathology and dampens mTORC signaling in mice. We will use complementary genetic and pharmacological approaches to reduce ODC activity and concomitant putrescine levels and polyamine flux. We propose to generate Tsc2-RG; Odc+/- compound mutants and determine if Odc haploinsufficiency affects (1) ODC activity and polyamine levels in brain lysates; (2) markers of neuropathology typical of TSC; and (3) levels of TSC/mTORC1 signaling proteins. Similarly, we will treat Tsc2-RG and control mice from postnatal days 1-21 with the ODC inhibitor difluoromethylornithine (DFMO) and determine its effects on these same phenotypic parameters. This project is expected to expand our understanding of the molecular basis of TSC by establishing a novel function for polyamines in determining TSC pathology. Additionally, these studies may define novel targets for TSC therapeutics.

项目概要结节性硬化症 (TSC) 是一种遗传性疾病，通常会导致神经系统疾病病理学，例如癫痫、发育障碍或神经精神疾病。 TSC 是由 TSC1 或 TSC2 基因的杂合失活突变引起的编码蛋白质结合伙伴hamartin和tuberin。二聚错构蛋白和马铃薯蛋白负调节雷帕霉素复合物 1 的机制靶标 mTORC1。对合成代谢信号的反应，激活的 mTORC1 刺激蛋白质合成，细胞生长和细胞周期进展。 TSC的发病机制很大程度上是由于 mTORC1 组成型激活和随后的细胞合成代谢。尽管取得了进步根据我们对 TSC 分子基础的了解，导致 TSC 的下游事件 TSC 病理学仍不清楚。使用公正的全球代谢组学分析方法，我们分析了来自良好表征的小鼠模型的海马组织 TSC，其中放射状胶质前体细胞中的 Tsc2 基因被条件性破坏 (Tsc2-RG)。这些和随后的数据揭示了多胺的上调腐胺和鸟氨酸脱羧酶 (ODC) 活性的增加，限速 Tsc2-RG 突变体中多胺合成中的酶。多胺对于细胞至关重要增殖和存活，有证据表明多胺和 mTORC 信号传导。在本提案中，我们将确定是否直接减少 ODC 活动改善 TSC 相关的神经病理学并抑制小鼠的 mTORC 信号传导。我们将使用互补的遗传和药理学方法来减少 ODC 活性和伴随的腐胺水平和多胺通量。我们建议生成 Tsc2-RG； Odc+/- 复合突变体并确定 Odc 单倍体不足是否影响 (1) 脑裂解液中 ODC 活性和多胺水平； (2)神经病理学标志物典型的 TSC； (3) TSC/mTORC1 信号蛋白的水平。同样，我们将对待 Tsc2-RG 和出生后 1-21 天使用 ODC 抑制剂的对照小鼠二氟甲基鸟氨酸 (DFMO) 并确定其对这些相同表型的影响参数。该项目有望扩大我们对分子的理解建立多胺测定 TSC 的新函数，为 TSC 奠定基础病理。此外，这些研究可能会确定 TSC 治疗的新靶点。