Mutational and functional analysis for Familial Parkinson's disease

帕金森病（PD）是第二大最常见的神经退行性疾病，65岁以上人群的患病率为1%。虽然大多数PD病例是散发的，但现在很清楚遗传因素有助于PD的发病机制。在本研究中，我们在负责PARK6的PINK1中发现了几个突变。在隐性遗传模式的患者中约<9%。此外，另一个致病基因DJ-1已被确定为PARK7的致病基因。然而，我们没有发现DJ-1突变。结合帕金基因突变分析，我们研究的大约40%的患者在报告的基因中没有突变。因此，我们认为可能存在未知基因的新突变。现在我们继续进行连锁研究，以鉴定一个新的基因。而基因产物的功能分析不仅可以为阐明单基因帕金森病的发病机制，也可以为阐明散发性帕金森病的发病机制提供有益的信息。在本研究中，我们发现了a-synuclein和parkin之间的共同途径，如多巴胺代谢。利用反义parkin链建立了体外敲除parkin的实验方法。parkin基因敲除诱导多巴胺醌衍生的多巴胺铬增加。有趣的是，这种增加被a-synuclein的表达所抑制。另外，作为帕金相互作用分子之一的14-3-3η抑制了帕金连接酶的活性。该系统通过a-synuclein的表达得以恢复。总之，PARK1和PARK2的基因产物具有共同的通路。研究结果还表明，所有基因产物在黑质变性的发病机制中具有共同的途径。

Parkinson's disease (PD) is the second most common neurodegenerative disorder with a prevalence of 1% in individuals older than 65 years of age. Although the majority of PD cases are sporadic, it is now clear that genetic factors contribute to the pathogenesis of PD. In the present study, we found several mutations in PINK1, responsible for PARK6. Approximately <9% among the patients with recessive mode of inheritance. Furthermore, another causative gene, DJ-1 has been identified as a causative gene for PARK7. However, we did not find out DJ-1 mutations. Taken together with parkin gene mutations analysis, approximately 40% of the patients we studied had no mutations in the reported genes. Thus, we believed that a novel mutation in unknown genes could be present. Now we continue to perform the linkage study for identification of a novel gene. In contrast, functional analysis for the gene products could provide us good information for elucidating the mechanism of not only monogenic PD but also sporadic PD. In the present study, we found a common pathway between a-synuclein and parkin such as dopamine metabolisms. We could establish the in vitro assay knock-down parkin using antisense parkin strand. Knock-down parkin induced the increasing of dopamine chrome derived from dopamine quinone. Interestingly, the increasing was inhibited by expression of a-synuclein. In addition, 14-3-3ηthat is one of parkin interaqctive molecules inhibited parkin ligase activities. This system was recovered by expression of a-synuclein. In conclusions, gene products for PARK1 and PARK2 shared common pathways. The findings also indicate that all the gene products share common pathways in the pathogenesis of nigral degeneration.