GATA2 as a therapeutic target in Parkinson's disease

描述（由申请人提供）：帕金森病（PD）与黑质（SN）中铁和1-突触核蛋白（1-syn）的病理增加有关，这些特征是使用农药鱼藤酮再现PD的动物模型。1-syn和铁都在黑质多巴胺神经元中积累并具有细胞毒性；然而，其病理积累的机制尚不清楚。我们已经确定了转铁蛋白/转铁蛋白受体2 （TfR2）介导的铁在黑质多巴胺神经元中积累的机制，并发现鱼藤酮大鼠多巴胺神经元中TfR2水平升高。GATA转录因子在造血过程中的作用已经被很好地表征，最近在体外被证明可以正向调节1-syn的表达。GATA2异构体在人类SN中表达，初步研究发现GATA2定位于大鼠SN中的多巴胺神经元。初步数据表明，GATA2在体外正调控TfR2的转录。因此，在体内，GATA2可能正协调调节黑质多巴胺神经元中的1-syn和TfR2，并且治疗性抑制GATA2可能同时改善PD中1-syn和铁的有害作用。本研究拟在大鼠SN中采用体内病毒介导的基因沉默来验证以下假设：1)GATA2调节大鼠黑质多巴胺神经元中的1-syn和TfR2, 2)抑制GATA2在黑质多巴胺神经元中导致鱼tenone处理后1-syn和铁的积累减少，从而减轻黑质纹状体变性。这项工作将研究pd的两个明显不同的病理特征- 1-突触核蛋白的积累和铁在黑质多巴胺神经元内的积累-如何通过抑制转录因子GATA2，在体内使用病毒介导的基因沉默来协调减弱。这些目标的成功完成将确立GATA2作为一个潜在的治疗靶点，可以利用基因治疗来改善人类PD中与1-syn和铁积累相关的细胞毒性。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is associated with pathological increases in iron and 1-synuclein (1-syn) in the substantia nigra (SN), and these features are reproduced animal models of PD that use the pesticide rotenone. Both 1-syn and iron accumulate in nigral dopamine neurons and are cytotoxic; however, the mechanism underlying their pathological accumulation is unknown. We have identified a transferrin/transferrin receptor 2 (TfR2)-mediated mechanism for iron accumulation in nigral dopamine neurons, and have found that TfR2 levels are increased in dopamine neurons in the rotenone rat. GATA transcription factors, whose role has been well characterized in hematopoiesis, have recently been shown to positively regulate the expression of 1-syn in vitro. The isoform GATA2 is expressed in human SN, and preliminary studies have localized GATA2 to dopamine neurons in rat SN. Preliminary data indicate that GATA2 positively regulates TfR2 transcription in vitro. Thus it is possible that GATA2 positively and coordinately regulates both 1-syn and TfR2 in nigral dopamine neurons in vivo, and that therapeutic GATA2 inhibition may simultaneously ameliorate the deleterious effects of both 1-syn and iron in PD. This proposal will use in vivo viral-mediated gene silencing in rat SN to test the following hypotheses: 1) GATA2 regulates 1-syn and TfR2 in rat nigral dopamine neurons, and 2) inhibition of GATA2 in nigral dopamine neurons leads to decreased accumulation of 1-syn and iron following rotenone treatment, thereby attenuating nigrostriatal degeneration. This work will examine how two apparently disparate pathological features of PD-the accumulation of 1-synuclein and the accumulation of iron within nigral dopamine neurons-may be coordinately attenuated via inhibition of the transcription factor, GATA2, using in vivo viral-mediated gene silencing. Successful completion of these aims would establish GATA2 as a potential therapeutic target that could be exploited using gene therapy to ameliorate the cellular toxicity associated with both 1-syn and iron accumulation in human PD. PUBLIC HEALTH RELEVANCE: Parkinson's disease (PD) is a neurodegenerative disorder that affects over one million Americans and currently no therapies alter disease progression. This research will evaluate whether a specific gene therapy intervention prevents brain degeneration by simultaneously acting on two important pathological features of the disease. A novel therapeutic intervention for eventual clinical use in human PD may be identified through this work, thereby addressing a major public health burden.