Fas (CD95)-induced regeneration of dopaminergic neurons

Fas (CD95) 诱导的多巴胺能神经元再生

• 批准号: 6479863
• 负责人: JULIE DESBARATS
• 金额: $ 13.5万
• 依托单位: MCGILL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6479863
• 关键词: CD95 molecule; Parkinson's disease; apoptosis; biological signal transduction; cell cycle; cell membrane; dopamine; embryo /fetus tissue /cell culture; flow cytometry; immunocytochemistry; laboratory mouse; methylphenyltetrahydropyridine; microscopy; motor neurons; nerve growth factors; nerve injury; nervous system regeneration; neural degeneration; neural growth associated protein; neurotoxicology; substantia nigra; tyrosine 3 monooxygenase

Parkinson's disease is characterized by the degeneration of dopamine- producing neurons in the substantial nigra of the brain. The resulting loss of dopamine leads to the cardinal symptoms of Parkinson's disease (PD), namely tremor, bradykinesia, postural instability, and rigidity. The disease is relentlessly progressive, ultimately resulting in a state of almost complete disability. Although PD can be slowed by current treatment protocols, it cannot be cured nor prevented at present. We have recently found that stimulating the cell surface molecule (Fas (CD95) on peripheral sensory neurons induces rapid, extensive neurite outgrowth in vitro, and can accelerate functional recovery in vivo after sciatic nerve crush injury. Contrary to the traditional view of Fas as a "death receptor", we propose that Fas engagement may induce regeneration of the dopaminergic neurons. In support of this notion, PD patients have elevated levels of soluble Fas in the substantial nigra. Soluble Fas acts as decoy receptor to prevent cell surface Fas from being engaged. Furthermore, mice with reduced Fas expression undergo progressive neural degeneration, and exhibit neurological and cognitive deficits. We propose to investigate the causal relationship between Fas expression and PD through the following specific aims: 1. To determine the physiological effects, and the signaling pathway(s) triggered, by Fas engagement on dopaminergic neurons. 2. To determine whether lack of Fas expression predisposes dopaminergic neurons to degeneration and/or MPTP toxicity (a model for PD). 3. To establish if anti-Fas antibody can stimulate dopaminergic neuron recovery in vivo. To accomplish these aims, we will use three models: tyrosine hydroxylase-positive (TH+) cell lines; in vitro cultures of embryonic mouse ventral mesencephalon cells enriched for TH+ neurons by flow cytometric sorting; and MPTP- induced nigrostriatal degeneration in the mouse as an in vivo model of PD. We will design our experiments to test the novel concept that Fas is able to induce regeneration in CNS neurons. The successful completion of these aims would yield a conceptually novel direction in the study of PD and neurodegenerative diseases in general, and a new target for innovative treatment strategies.

帕金森氏病的特征是大脑黑质中产生多巴胺的神经元变性。由此产生的多巴胺的损失导致帕金森病（PD）的主要症状，即震颤、运动迟缓、姿势不稳定和僵硬。这种疾病是无情的进展，最终导致几乎完全残疾的状态。虽然目前的治疗方案可以减缓PD，但目前无法治愈或预防。我们最近发现，刺激外周感觉神经元上的细胞表面分子（Fas（CD 95））在体外诱导快速、广泛的神经突生长，并且可以加速坐骨神经挤压损伤后在体内的功能恢复。与传统的Fas作为“死亡受体”的观点相反，我们认为Fas参与可能诱导多巴胺能神经元的再生。为了支持这一观点，PD患者的黑质中可溶性Fas水平升高。可溶性Fas作为诱饵受体，阻止细胞表面Fas的结合。此外，Fas表达降低的小鼠经历进行性神经变性，并表现出神经和认知缺陷。本研究拟通过以下几个方面探讨Fas表达与PD的因果关系：1.确定Fas参与多巴胺能神经元的生理效应和触发的信号通路。2.确定Fas表达缺乏是否使多巴胺能神经元易于变性和/或MPTP毒性（PD模型）。3.目的：研究抗Fas抗体是否能促进多巴胺能神经元的恢复。为了实现这些目标，我们将使用三种模型：酪氨酸羟化酶阳性（TH+）细胞系;体外培养的胚胎小鼠腹侧中脑细胞富集TH+神经元的流式细胞术分选;和MPTP诱导的黑质纹状体变性的小鼠作为体内模型的PD。我们将设计我们的实验来测试新的概念，Fas能够诱导CNS神经元再生。这些目标的成功完成将在PD和神经退行性疾病的研究中产生一个概念上的新方向，以及创新治疗策略的新目标。