Aberrant Protein Kinase C Signaling in Alzheimer's Disease

摘要/摘要 我们提出的研究的总体愿景是了解分子，细胞和电生理 蛋白激酶C（PKC）异常信号传导促进阿尔茨海默病病理学的机制 疾病（AD）。这种与年龄相关的痴呆症的特征是信号失调，突触退化， 神经元死亡，并最终导致参与学习和记忆的大脑区域缩小。而 已经有大量的努力致力于了解细胞外淀粉样蛋白-β（Aβ）斑块的作用， 作为该疾病的标志，新出现的证据指出PKC同工酶的信号失调， 在疾病中的潜在致病作用。我们组建了一个团队， PKC机制和突触机制的专业知识，以了解异常PKC信号传导如何促进 与疾病表型的关系最近从全基因组中搜索与AD相关的罕见功能变体 来自迟发性AD家族的测序数据已经在这两种基因中鉴定出高度外显的变异， 与AD患病状态共分离的多个家族中的PKC β（PRKCA）和PKC β（PRKCH）。所有PKC抑制剂 变体显示增强的活性，我们对一种变体（PKC β M489 V）的详细分析已经确定， 它足以重新连接大脑磷酸化蛋白质组，驱动突触变性，并损害认知能力。 小鼠模型增强的PKC功能驱动AD病理学与无偏磷酸化蛋白质组学一致 分析已经确定升高的PKC信号传导是AD患病大脑中最早的事件之一。因此，在本发明中， 支持这一观点的假设是两种PKC同工酶，神经元中的PKC β和小胶质细胞中的PKC β， 在脑内稳态中的重要作用，并且任何一个的失调都有助于AD的病理学。我们的目标 结合联合收割机最先进的蛋白质组学、生物化学、成像和电生理学方法， 研究PKC β或PKC β的异常信号传导如何影响神经元或小胶质细胞功能的分子机制。 我们还将测试的假设，增加蛋白水平的任何PKC是一个生物标志物在AD。这个项目 应该在我们对神经变性和AD的理解方面取得重大进展， 针对这种毁灭性疾病的新治疗策略。

Summary/Abstract The overall vision of our proposed research is to understand the molecular, cellular and electrophysiological mechanisms by which aberrant signaling by protein kinase C (PKC) promotes the pathology of Alzheimer’s Disease (AD). This age-related dementia is characterized by deregulated signaling, degeneration of synapses, neuronal death and, ultimately, a reduction in the size of brain regions involved in learning and memory. While significant efforts have been devoted to understanding the role of extracellular amyloid-β (Aβ) plaques that are a hallmark of the disease, emerging evidence points to deregulated signaling by PKC isozymes playing a potentially causative role in the disease. We have assembled a team with extensive and complementary expertise in PKC mechanisms and synaptic mechanisms to understand how aberrant PKC signaling contributes to the disease phenotype. Recent searches for rare functional variants associated with AD from whole genome sequencing data from families with late-onset AD have identified highly penetrant variants in the genes for both PKC (PRKCA) and PKC (PRKCH) in multiple families that co-segregate with AD affection status. All PKC variants display enhanced activity, and our detailed analysis of one variant (PKC M489V) has established that it is sufficient to rewire the brain phosphoproteome, drive synaptic degeneration, and impair cognition in a mouse model. Enhanced PKC function driving AD pathology is consistent with unbiased phosphoproteomics analysis that have identified elevated PKC signaling as one of the earliest events in AD diseased brains. Thus, the hypothesis driving this proposal is that two PKC isozymes, PKC in neurons and PKC in microglia, play essential roles in brain homeostasis and that deregulation of either contributes to the pathology of AD. We aim to combine state-of-the-art proteomics, biochemical, imaging and electrophysiological approaches in order to study molecular mechanisms of how aberrant signaling by PKC or PKC impact neuronal or microglial function. We also will test the hypothesis that increased protein levels of either PKC is a biomarker in AD. This project should make significant strides in our understanding of neurodegeneration and AD as well as providing possible new therapeutic strategies against this devastating disease.