Tissue Culture Models of Lesch-Nyhan Disease

描述（由申请人提供）：虽然Lesch-Nyhan病（LND）的潜在基因缺陷是已知的，并且基底节区功能的改变与神经和行为异常的表现密切相关，但缺乏次黄嘌呤-鸟嘌呤磷酸核糖基转移酶（HPRT）活性和选择性多巴胺丢失之间的机制联系尚不清楚。hprt缺乏的细胞模型为理解重要的分子扰动和快速评估潜在的治疗药物提供了一个强大而有效的方法。在体内观察到，在啮齿动物多巴胺能细胞系中选择HPRT突变导致细胞多巴胺含量持续下降。这不能通过随后的HPRT功能恢复而逆转。我们建议利用现有的细胞模型以及干细胞技术的最新进展，在体外产生多巴胺能神经元，以研究HPRT缺乏对多巴胺能规范和分化的影响。了解嘌呤打捞和多巴胺稳态之间的联系是揭示LND病理基础的关键，而确定正常多巴胺能张力所需HPRT的时间窗口为开发有效的治疗方法，特别是基因替代策略提供了有意义的基础。

DESCRIPTION (provided by applicant): Although the underlying gene defect in Lesch-Nyhan Disease (LND) is known and altered basal ganglia function strongly implicated in the manifestation of neurological and behavioral abnormalities, the mechanistic connection between the lack of hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity and selective dopamine loss remains unclear. Cell models of HPRT-deficiency provide a powerful and efficient approach to understanding the important molecular perturbations and rapid evaluation of potential therapeutic agents. As observed in vivo, selection for HPRT mutations in rodent dopaminergic cell lines has resulted in a consistent decrease in cellular dopamine content. This has not been reversible by subsequent restoration of HPRT function. We propose to utilize existing cell models as well as recent advancements in stem cell technology that generate dopaminergic neurons in vitro to investigate alterations in dopaminergic specification and differentiation conferred by HPRT deficiency. Understanding the link between purine salvage and dopamine homeostasis is key to unraveling the pathological basis of LND, while identifying the temporal window wherein HPRT is required for normal dopaminergic tone provides a meaningful basis for the development of effective therapeutics, especially gene replacement strategies.