Role of LRRK2 in idiopathic Parkinson's disease

LRRK2基因突变导致家族性帕金森病(PD)，在某些人群中，可能占全部帕金森病的40% 案例3.LRRK2基因座也包含特发性帕金森病(IPD)的危险因素；然而，LRRK2在 典型的IPD尚不清楚。此外，LRRK2与其他与帕金森病相关的基因和蛋白的关系，如 α--突触核蛋白，也是相对未被开发的。而突变体LRRK2导致神经退行性变的机制(S) 都不是完全确定的，人们普遍认为致病突变可能与激酶的增加有关 活性，至少在完好的细胞中是原位的。然而，理解内源性、野生型的作用的一个关键障碍 在IPD中，LRRK2缺乏一种实用的、高分辨率的检测其激活状态的方法。 我们已经开发并验证了一对新的邻近结扎分析，具有出色的解剖分辨率，可以 快速提供有关LRRK2的激活状态、细胞定位和生理调节的信息。这个 实验基于(I)S1292的磷酸化和(Ii)14-3-3与LRRK2的解离。使用这个和其他的分析方法，我们 有初步证据表明(I)LRRK2在IPD的黑质纹状体神经元中被激活；(Ii)亚致死浓度 鱼藤酮激活LRRK2；(Iii)体内过表达α-突触核蛋白激活黑质纹状体神经元LRRK2； LRRK2的激活是由氧化机制介导的。我们现在建议研究LRRK2在IPD中的作用及其 与α-突触核蛋白和线粒体潜在的生理相互作用。我们将调查以下问题：(1) LRRK2在人IPD脑组织中的激活状态是什么？(2)内源性LRRK2在多大程度上可以激活 以鱼藤酮大鼠为模型？(3)α-突触核蛋白激活内源性WTLRRK2吗？(4)氧化应激激活吗？ LRRK2？

Mutations in LRRK2 cause familial Parkinson disease (PD) and, in some populations, may account for up to 40% of all cases3. The LRRK2 gene locus also contains a risk factor for `idiopathic' PD (iPD); however, the role of LRRK2 in typical iPD is not clear. Furthermore, the relationship of LRRK2 to other genes and proteins associated with PD, such as α-synuclein, is also relatively unexplored. While the mechanism(s) by which mutant LRRK2 causes neurodegeneration are not entirely certain, it is generally believed that disease-causing mutations may be associated with increased kinase activity, at least in situ in intact cells. However, a critical barrier to understanding the role of endogenous, wildtype LRRK2 in iPD is the absence of a practical, high-resolution assay for its activation state. We have developed and validated a pair of novel proximity ligation assays with excellent anatomical resolution that can rapidly provide information regarding activation state, cellular localization and physiological regulators of LRRK2. The assay is based on (i) S1292 phosphorylation and (ii) dissociation of 14-3-3 from LRRK2. Using this and other assays, we have preliminary evidence that (i) LRRK2 is activated in nigrostriatal neurons in iPD; (ii) sublethal concentrations of rotenone activate LRRK2; (iii) overexpression of α-synuclein in vivo activates LRRK2 in nigrostriatal neurons; (iv) LRRK2 activation is mediated by oxidative mechanisms. We now propose to examine the role of LRRK2 in iPD and its potential physiological interactions with α-synuclein and mitochondria. We will investigate the following questions: (1) What is the activation state of LRRK2 in human iPD brain tissue? (2) To what extent can endogenous LRRK2 activation be modeled in the rotenone rat? (3) Does!α-synuclein activate endogenous WT LRRK2? (4) Does oxidative stress activate LRRK2?