PROJECT 2: MEF2 AS A SENSOR OF MITOCHONDRIAL OXIDATIVE STRESS

帕金森病（PD）涉及神经元的病理性损失。长期目标是 我们实验室的研究是了解环境和遗传神经毒性剂如何相互作用， 信号和调节PD发病机制中的存活/凋亡机制。线粒体功能障碍 被认为是介导PD中多巴胺能神经元死亡的关键机制。但 PD相关环境毒物影响线粒体的详细分子机制！ 转录和活性仍然未知。我们最近发表的研究结果强调了核武器的关键作用。 转录因子肌细胞增强因子2（MEF 2）在神经元存活。我们未发表的研究 揭示了线粒体中MEF 2的意外存在和功能。在此基础上，我们提出探索 线粒体MEF 2在介导和整合PD相关环境毒性信号中的作用 多巴胺神经元退化中的有毒物质。我们建议：确定线粒体的作用 MEF 2在多巴胺能神经元线粒体基因组转录调控中的作用; II.研究 PD相关环境毒物对线粒体MEF 2的调节作用 细胞模型中的功能障碍和神经元死亡;和III.建立规则和功能 线粒体MEF 2在毒物诱导的PD动物模型中的作用。为了实现目标l-lll，我们将建立 MEF 2在多巴胺能神经元细胞系SN 4741线粒体基因转录中作用 原代神经元和测试一组模型毒物，包括MPP+（MPTP的代谢产物）和鱼藤酮， 细胞和啮齿类动物模型来研究线粒体MEF 2的失调是否介导了毒性 这些毒素的影响。我们将尝试将我们的发现扩展到PD患者， 线粒体MEF 2活性与疾病的关系。我们将结合形态学，生物化学， 功能和遗传方法在拟议的研究。这些研究将使我们能够评估 靶向线粒体MEF 2是环境毒物诱导的多巴胺神经元凋亡的基础。 从这项研究中获得的新见解将证明环境毒物如何破坏 线粒体功能，为多巴胺神经元的丧失提供了分子解释， 与散发性和家族性PD以及潜在的治疗靶点相关。

Parkinson's disease (PD) involves pathological loss of neurons. The long-term objective of this research in our laboratory is to understand how environmental and genetic neurotoxic agents interact to signal and regulate the survival/apoptosis machinery in PD pathogenesis. Mitochondrial dysfunction has been propsoed as a key mechanism that mediates demise of dopamingergic neurons in PD. However, the detailed molecular mechanisms by which PD relevant environmental toxicants affect mitochondria! transcription and activity remain unknown. Our recently published findings highlight the key role.of nuclear transcription factor myocyte enhancer factor 2 (MEF2) in neuronal survival. Our unpublished studies have revealed unexpected presence and function of MEF2 in mitochondria. Based on this, we propose to explore the role of mitochondrial MEF2 in mediating and integrating the toxic signals of PD relevant environmental toxicants in the degeneration of dopamine neurons. We propose to: I. Determine the role of mitochondrial MEF2 in regulating transcription of mitochondrial genome in dopaminergic neurons; II. Study the regulation of mitochondrial MEF2 by PD relevant environmental toxicants in mitochondrial dysfunction and neuronal death in cellular models; and III. Establish the regulation and function of mitochondrial MEF2 in toxicant-induced animal models of PD. To accomplish aim l-lll, we will establish the role of MEF2 in mitochondrial gene transcription in dopaminergic neuronal cell line SN4741 cells and primary neurons and test a group of model toxicants including MPP+(metabolite of MPTP) and rotenone in cellular and rodent modeis to investigate whether de-regulation of mitochondrial MEF2 mediates the toxic effects of these toxins. We will attempt to extend our findings to PD patients by correlating the levels and activit of mitochondrial MEF2 with the disease. We will use a combination of morphological, biochemical, functional and genetic methods in the proposed study. These studies will allow us to assess whether targeting mitochondrial MEF2 underlies environmental toxicant-induced apoptosis of dopamine neurons. The novel insight gained from this study will demonstrate how environmental toxicants may disrupt mitochondrial function, providing a molecular explanation for the loss of dopamine neurons that may relevant to both sporadic and familial PD and a potential therapeutic target.