Pin1-Catalyzed Protein Conformational Regulation in Alzheimer's Disease

Pin1 催化的阿尔茨海默氏病蛋白质构象调节

• 批准号: 8720649
• 负责人: Kun Ping Lu
• 金额: $ 35.67万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8720649
• 关键词: 19p13.2; Address; Affect; Alzheimer' s Disease; Amyloid beta-Protein; Antibodies; Biological Process; Brain; Cells; Deposition; Development; Disease; Down-Regulation; Early Diagnosis; Enzymes; Genes; Goals; Human; In Vitro; Incidence; Knock-out; Knockout Mice; Laboratories; Late Onset Alzheimer Disease; Lead; Life; Mediating; Memory Loss; Methods; Molecular; Molecular Conformation; Mus; Mutant Strains Mice; Nerve Degeneration; Neurofibrillary Tangles; Neurons; Outcome; Pathogenesis; Pathology; Phosphoproteins; Phosphorylation; Play; Proline; Property; Protein Conformation; Protein Dephosphorylation; Protein Isoforms; Proteins; Regulation; Resistance; Role; Sampling; Serine; Signal Transduction; Tauopathies; Testing; Threonine; Transgenic Mice; age related; amyloid precursor protein processing; cognitive function; design; effective therapy; hTau Mice; hyperphosphorylated tau; in vivo; mouse model; neurobehavior; neurofibrillary tangle formation; new technology; novel diagnostics; novel therapeutic intervention; overexpression; oxidation; prevent; research study; tau Proteins; tau conformation; tau function; tool

DESCRIPTION (provided by applicant): The neuropathological hallmarks of Alzheimer's disease (AD) are tangles made of hyperphosphorylated tau (p- tau) and plaques consisted of Abeta deposits. Tau hyperphosphorylation especially on Ser or Thr residues before Pro (pSer/Thr-Pro) precedes tangle formation. We have recently found that certain pSer/Thr-Pro motifs exist in two distinct cis and trans conformations and identified a unique enzyme, Pin1 that specifically catalyzes their isomerization in vitro. Importantly, Pin1 controls a subset of key regulators to help coordinate their functions and its deregulation can contribute to certain diseases, notably AD. Pin1 acts on the pThr231-Pro motif in p-tau to inhibit tau-related pathology (tauopathy) and on the pThr668-Pro motif in APP to reduce A?- pathology. Pin1 knockout mice develop age-dependent tau- and A?-pathologies, whereas Pin1 overexpression inhibits tauopathy in mice. These results are relevant to human AD because Pin1 is inhibited in MCI and AD neurons by various mechanisms, but preventing Pin1 inhibition is associated with delayed onset of AD. Human Pin1 gene is located to 19p13.2, a new locus associated with late-onset AD. We thus proposed that Pin1 might help protect against neurodegeneration in AD by regulating protein conformations. However, a major challenge is the lack of any tool available that is able to distinguish cis from trans pSer/Thr-Pro conformation in a native protein. Thus there is no direct evidence for the presence of these two p- tau conformations and their conformation-specific functions or regulation in tauopathy. Moreover, whether Pin1 and p-tau conformations play any role in cognitive function relevant to AD is also not known. To address these critical issues, we developed Pin1 conditional knockout mice and a novel technology to generate a first pair of antibodies able to detect specifically cis or trans pThr231-Pro motif in p-tau. Our preliminary results suggest that Pin1 increased cis to trans isomerization of pThr231-tau in vitro and in mice, and that cis, but not trans, pThr231-tau was significantly elevated in MCI brains, and further accumulated in AD. This proposal is designed to test our hypotheses that the pathological p-tau is conformation-specific and that modulating such conformation by Pin1 and others would affect tauopathy and cognitive function relevant to AD. Aim 1 is to determine which p-tau conformations are pathologicaly more relevant during tauopathy using AD mouse models and human AD samples. Aim 2 is to determine the impact of modulating p-tau conformations by Pin1 and other methods on tauopathy in mice, and the relationship between Pin1 and tau conformations in human AD, and the mechanisms underlying the Pin1 action in vitro and in cells. Aim 3 is to use neuron-specific Pin1 knockout or overexpression or other methods to determine the role of Pin1 and p-tau conformations in cognitive function relevant to AD. These experiments would further define the role of Pin1 and its catalyzed conformational changes in AD, and could lead to new strategies for treating tauopathy. These studies would offer the first in vivo approach to study post-phosphorylation conformational regulation.

描述（由申请人提供）：阿尔茨海默病（AD）的神经病理学标志是由过度磷酸化的tau（p-tau）构成的缠结和由Abeta沉积物构成的斑块. Tau过度磷酸化，特别是在Pro（pSer/Thr-Pro）之前的Ser或Thr残基上，先于缠结形成。我们最近发现，某些pSer/Thr-Pro基序存在两种不同的顺式和反式构象，并确定了一种独特的酶，Pin 1，专门催化其异构化在体外。重要的是，Pin 1控制着一组关键调节因子，以帮助协调它们的功能，而其失调可能导致某些疾病，特别是AD。Pin 1作用于p-tau中的pThr 231-Pro基序以抑制tau相关病理（tau病变），并作用于APP中的pThr 668-Pro基序以减少A？病理Pin 1基因敲除小鼠产生年龄依赖性tau蛋白和A？在小鼠中，Pin 1过表达抑制tau蛋白病。这些结果与人类AD相关，因为Pin 1在MCI和AD神经元中通过各种机制被抑制，但阻止Pin 1抑制与AD的延迟发作相关。人类Pin 1基因定位于19p13.2，是一个与晚发性AD相关的新位点。因此，我们提出Pin 1可能通过调节蛋白质构象来帮助预防AD中的神经变性。 然而，一个主要的挑战是缺乏任何可用的工具，能够区分顺式和反式pSer/Thr-Pro构象的天然蛋白质。因此，没有直接证据表明这两种p-tau构象的存在及其在tau蛋白病中的构象特异性功能或调节。此外，Pin 1和p-tau构象是否在与AD相关的认知功能中发挥任何作用也是未知的。为了解决这些关键问题，我们开发了Pin 1条件性敲除小鼠和一种新技术，以产生能够特异性检测p-tau中顺式或反式pThr 231-Pro基序的第一对抗体。我们的初步结果表明，Pin 1增加顺式到反式异构化的pThr 231-tau在体外和小鼠，顺式，但不是反式，pThr 231-tau在MCI脑显着升高，并进一步积累在AD。该提议旨在验证我们的假设，即病理性p-tau是构象特异性的，并且通过Pin 1和其他人调节这种构象将影响与AD相关的tau蛋白病和认知功能。 目的1是使用AD小鼠模型和人AD样品确定哪些p-tau构象在tau蛋白病期间在病理学上更相关。目的2是确定通过Pin 1和其他方法调节p-tau构象对小鼠tau病变的影响，以及Pin 1和人类AD中tau构象之间的关系，以及Pin 1在体外和细胞中作用的机制。目的三是利用神经元特异性Pin 1基因敲除或过表达等方法，研究Pin 1和p-tau蛋白构象在AD相关认知功能中的作用。这些实验将进一步确定Pin 1及其催化的构象变化在AD中的作用，并可能导致治疗tau蛋白病的新策略。这些研究将提供第一个在体内的方法来研究磷酸化后的构象调控。