ASTROCYTE DELIVERY OF GDNF IN PARKINSONS DISEASE

产品说明：胶质细胞系衍生的神经营养因子（GDNF）是最近鉴定的肽，其显示在帕金森病的啮齿动物和灵长类动物模型中引起显著的恢复/保护作用。 虽然治疗效果涉及其临床应用，但由于GDNF不穿过BBB，因此体内递送的问题仍然是一个问题。 使用离体基因治疗方法，申请人已经表明用复制缺陷型逆转录病毒载体转导的星形胶质细胞在培养物中和脑内移植后表达重组GDNF。 该提案中描述的初步研究表明，当在小鼠中6-OHDA损伤前几天植入黑质附近时，产生GDNF的星形胶质细胞几乎完全保护黑质多巴胺能胞体及其相关的纹状体纤维。所提出的研究旨在进一步表征移植星形胶质细胞表达重组GDNF，并研究潜在的体内机制，通过该机制，连续暴露于低量GDNF可降低成年黑质纹状体神经元对6-OHDA诱导的毒性的敏感性。 此外，实验提出，以确定是否GDNF通过转基因星形胶质细胞交付恢复功能，以前被6-OHDA损伤的萎缩神经元。 使用PD的鼠模型，本研究的目的是：1）研究脑内移植后转基因星形胶质细胞对GDNF的长期表达; 2）研究谷胱甘肽系统和磷脂酰肌醇3激酶（PI 3 K）调节的信号转导事件在GDNF介导的神经保护中的潜在作用; 3）以确定在6-OHDA诱导的变性开始后，产生GDNF的星形胶质细胞是否恢复受损黑质纹状体神经元的多巴胺能功能。 这些目标将在帕金森病的小鼠6-OHDA模型中使用分子、组织培养、行为和神经化学方法的组合来解决。

DESCRIPTION: (Verbatim from the Applicant's Abstract) Glial cell line derived neurotrophic factor (GDNF) is a recently identified peptide shown to elicit marked restorative/protective effects in both rodent and primate models of Parkinson's disease. Although the therapeutic effects implicate its clinical use, since GDNF does not cross the BBB the problem of in vivo delivery still remains an issue. Using an ex vivo gene therapy approach, the applicant has shown that astrocytes transduced with a replication defective retroviral vector express recombinant GDNF in culture and following intracerebral transplantation. Preliminary studies described in the proposal demonstrate that GDNF producing astrocytes provide nearly complete protection of both nigral dopaminergic perikarya and their associated striatal fibers, when implanted near the substantia nigra several days prior to a 6-OHDA lesion in the mouse. The proposed studies are designed to further characterize the expression of recombinant GDNF by grafted astrocytes and to investigate potential in vivo mechanisms by which continuous exposure to low amounts of GDNF confers decreased susceptibility of adult nigrostriatal neurons to 6-OHDA induced toxicity. In addition, experiments are proposed to determine whether GDNF delivered via transgenic astrocytes restores function to atrophic neurons previously damaged by 6-OHDA. Using a murine model of PD, the proposed studies are designed to address the following Specific aims 1) to characterize the long-term expression of GDNF by transgenic astrocytes following intracerebral transplantation 2) to investigate the potential role of the glutathione system and phosphatidylinositol 3 kinase (PI3K) regulated signaling events in GDNF mediated neuroprotection in vivo using transgenic astrocytes and 3) to determine whether GDNF producing astrocytes restore dopaminergic function to damaged nigrostriatal neurons following the onset of degeneration induced by 6-OHDA. These aims will be addressed using a combination of molecular, tissue culture, behavioral and neurochemical methods, in a mouse 6-OHDA model of Parkinson's disease.