RLIP, Mitochondrial Dysfunction in Alzheimer’s Disease

项目总结 阿尔茨海默病(AD)是一种神经退行性疾病，影响很大一部分人的衰老 人口。尽管这种疾病很普遍，但没有一种特定的治疗方法可以预防或治疗这种疾病。关于网络信息技术的研究 这种疾病的病理生理学和新药的测试仅限于携带有 AD相关基因的突变版本，包括APP、PSEN1、APOEɛ4和ob(瘦素)。由于氧化 脑内应激(OS)被认为与AD的发病有关，OS的标志物如蛋白质 氧化、脂质氧化、DNA氧化、糖氧化和线粒体功能障碍也可能有助于 AD的标志物。RalBP1(Rlip)是一种应激激活蛋白，在OS防御中发挥关键作用，因为 测定谷胱甘肽结合的氧化代谢产物外排中的酶。虽然我们有广泛的 以Rlip作为中枢重要的氧化应激防御机制在糖尿病的病因中的作用为特征 除了癌症、代谢综合征和糖尿病，我们最近才开始研究它在神经元中的功能。我们的 初步数据和出版表明，Rlip基因敲除在神经细胞和Rlip小鼠中发展起来 阿尔茨海默病与氧化应激/线粒体功能障碍和突触损伤有很强的机制联系。此外， Rlip缺陷小鼠和神经元增加了大脑中的OS，下调了NRF2，哪个OS 正常情况下会上调。这种失调的NRF2反应可能会进一步加剧氧化 在这些小鼠中，压力、异物代谢受损和线粒体功能失调。我们提供 耐人寻味的初步证据表明人类死后阿尔茨海默病的大脑中存在Rlip缺陷和 培养的Rlip缺陷小鼠和Rlip缺陷神经元的线粒体结构、功能和蛋白质。 我们的初步研究表明，Rlip耗竭在表观上调节着几个与AD相关的基因，包括 CREBBP，一种与神经认知有关的基因。Rlip/-模型将允许我们形成氧化应激 阿尔茨海默病的动物模型，这反过来将有助于开发治疗AD的药物和 进行将导致AD生物学的新发现的研究。根据我们的初步调查结果，我们 假设Rlip缺乏会导致氧化应激，氧化应激会加剧神经变性和 神经认知功能失调；因此，通过Rlip减少氧化应激信号 上调可能会改善线粒体和突触功能以及认知行为。根据建议的 目的1)我们将研究Rlip基因敲除小鼠是否有神经认知、组织病理学、生化和 类似于人源化Aβ基因敲入(HAβ-Ki)小鼠的神经元缺陷，以及2)Rlip 上调可改善HAβ-KI模型的表型严重性。这些研究将提供新的见解 对阿尔茨海默病氧化应激防御的调节，并可能导致治疗阿尔茨海默病的新方法。

PROJECT SUMMARY Alzheimer's disease (AD) is a neurodegenerative disorder that affects a large proportion of the aging population. Despite its prevalence, no specific treatments can prevent or treat this disease. Research on the pathophysiology of the disease and the testing of new drugs is limited to transgenic mouse models harboring mutated versions of AD-related genes, including APP, PSEN1, APOEɛ4, and ob (leptin). Since oxidative stress (OS) in the brain is believed to be involved in AD pathogenesis, markers of OS such as protein oxidation, lipid oxidation, DNA oxidation, glycoxidation, and mitochondrial dysfunction may also have utility as markers for AD. RalBP1 (Rlip) is a stress-activated protein that plays a crucial role in OS defense as the rate- determining enzyme in the efflux of the GSH-conjugated oxidative metabolites. While we have extensively characterized the role of Rlip as a centrally important oxidative stress-defense mechanism in the etiologies of cancer, metabolic syndrome, and diabetes, we have only recently begun to study its function in neurons. Our preliminary data and published suggests that the Rlip knockout in neuronal cells and Rlip mice developed strong mechanistic links with oxidative stress/mitochondrial dysfunction and synaptic damage in AD. Further, Rlip deficient mice and neurons have increased OS in the brain and downregulation of NRF2, which OS normally up-regulates. This dysregulated NRF2 response likely contributes to further exacerbated oxidative stress, impaired xenobiotic metabolism, and dysregulated mitochondrial functions in these mice. We provide intriguing preliminary evidence of Rlip deficiency in human postmortem AD brains and abnormalities of mitochondrial structure, function, and proteins in Rlip deficient mice and in Rlip deficient neurons in culture. Our preliminary studies show that Rlip depletion epigenetically regulates several AD-linked genes, including CREBBP, a gene implicated in neurocognition. The Rlip+/- model will allow us to develop an oxidative stress animal model of AD, which in turn will be helpful in the development of drugs for the treatment of AD and in conducting studies that will lead to novel findings on AD biology. Based on our preliminary findings, we hypothesize that Rlip deficiency causes oxidative stress, which exacerbates neurodegeneration and dysregulation of neurocognitive functions; therefore, reducing oxidative stress signaling through Rlip upregulation may improve mitochondrial and synaptic functions and cognitive behavior. Under the proposed Aims 1) we will study whether Rlip knockout mice have neurocognitive, histopathological, biochemical, and neuronal deficits resembling those seen in humanized Aβ knock-in (hAβ-KI) mice, and 2) whether Rlip upregulation ameliorates the phenotypic severity of the hAβ-KI model. These studies will offer novel insights into the regulation of oxidative stress defenses in AD and may lead to new treatments for AD.