Mitochondrial calcium uptake in Alzheimer’s disease

摘要： 阿尔茨海默病（AD）的特征在于伴随神经元细胞死亡的记忆丧失， 代谢功能障碍许多研究报道了神经元细胞内钙离子的失调 (1Ca2+）信号传导作为AD发病机制中的早期事件。据认为，神经元1Ca 2+的长期升高 促进过多的线粒体钙（mCa 2+）摄取，但迄今为止还没有研究探讨了这种贡献 mCa 2+摄取与疾病进展的关系。由于mCa 2+通量是细胞呼吸的重要调节因子， 细胞死亡，这两者都参与了AD的发病机制，我们假设mCa 2+超载是一个关键， AD病理学的贡献者，并可能有助于代谢缺陷和神经元死亡。定义的作用 我们已经产生了3xTg-AD突变小鼠，其具有神经元特异性缺失， 线粒体钙单向转运蛋白（MCU），这是mCa 2+摄取所必需的。此外，我们还生成了一个 表达最近鉴定的线粒体钙单向转运体β亚基的功能获得性突变小鼠 （MCUb）。最近有报道称MCUB是mCa 2+摄取的负调节剂，我们观察到 在AD中的表达有显著变化。这些模型将允许进行因果关系实验，以测试mCa 2 + 摄取驱动AD进展。将检查小鼠的记忆、淀粉样变性、tau病理学的改变， 氧化应激、突触和代谢功能。初步数据表明，mCa 2+摄取过载损害 清除错误折叠的蛋白质和功能失调的线粒体。因此，我们将机械地检查 mCa 2+交换与自噬和线粒体吞噬途径之间的联系。最理想的情况是，拟议的研究 将发现AD和相关线粒体功能障碍的新治疗靶点， 和研究平台，促进了Pis的独立研究事业。

Abstract: Alzheimer's disease (AD) is characterized by the loss of memory accompanied by neuronal cell death and metabolic dysfunction. Numerous studies have reported a dysregulation in neuronal intracellular calcium (1Ca2+) signaling as an early event in AD pathogenesis. It is thought that a prolonged elevation in neuronal 1Ca2+ promotes excessive mitochondrial calcium (mCa2+) uptake, yet to date no study has examined the contribution of mCa2+ uptake to disease progression. Since mCa2+ flux is an important regulator of cellular respiration and cell death, both of which are involved in AD pathogenesis, we hypothesize that mCa2+ overload is a key contributor to AD pathology and may contribute to metabolic deficits and neuronal demise. To define the role of mCa2+ exchange in AD we have generated 3xTg-AD mutant mice with neuronal-specific deletion of Mitochondrial Calcium Uniporter (MCU), which is required for mCa2+ uptake. In addition, we have generated a gain-of-function mutant mouse expressing the recently identified mitochondrial calcium uniporter beta subunit (MCUb). MCUb was recently reported as a negative regulator of mCa2+ uptake and we have observed substantial changes in its expression in AD. These models will allow causative experimentation to test if mCa2+ uptake drives AD progression. Mice will be examined for alterations in memory, amyloidosis, tau-pathology, oxidative stress, synaptic and metabolic function. Preliminary data suggest that mCa2+ uptake overload impairs the clearance of misfolded proteins and dysfunctional mitochondria. Therefore, we will mechanistically examine the link between mCa2+ exchange and autophagic and mitophagic pathways. Optimally, the proposed studies will discover new therapeutic targets for AD and associated mitochondrial dysfunction and provide a training and research platform to promote the Pis independent research career.