Generating Blood-based Diagnosis for Alzheimer Disease

描述（由申请人提供）：目前缺乏基于血液的诊断要求AD患者接受侵入性脊髓液（CSF）穿刺，昂贵的MRI或PET成像或艰巨的心理测试，这些都不适合我们的老年人并且费用高昂。从战略上讲，我们将通过生成可在外周血单核细胞（PBMC）和血清/血浆中检测到的系统生物标志物来解决这一未满足的需求，重点关注两类分子，微RNA及其靶基因，它们通常表现出反比关系，因为前者非编码RNA的功能是部分抑制后者的表达，作为“调光开关”，通过结合在信息的编码区，从而降解它，或者在3 ' -非翻译区。抑制翻译。因此，关键microrna及其靶点可以作为疾病生物标志物，在“跷跷板”平衡中，适用于新的诊断和/或治疗。我们对16名AD患者和16名年龄匹配的正常老年人（NEC）进行的小规模队列研究显示：1。AD PBMC在信息水平上主要下调基因表达；和2。同一个体PBMC中microRNA （miR）表达的相关上调。在本提案中，我们关注的是一个特定的上调microRNA miR-34a，其已知的靶点是SIRT1， cdk4, cdk6, cyclin E2， bcl2等。SIRT1是由7个成员组成的沉默信息调节蛋白家族的一员。热量限制通过触发SIRT1的表达来延长寿命，这也可以被白藜芦醇（一种红葡萄酒多酚）模仿。SIRT1的减少与Tau的积累和A242的产生有关，这是AD发病的两个标志。因此，我们认为阿尔茨海默病在PBMC和血清/血浆中存在可检测到的全身效应；miR-34a上调可诱导SIRT1下调，并伴有相应的病理生理结果。在本提案中，我们计划生成miR-34a/SIRT1靶对比（TPR）指数的“跷跷板”变化，以量化疾病的存在和进展；这些指标还应提供前所未有的药物疗效评价。该快速通道计划分为两个阶段，以我们现有的小队列研究作为更大队列研究的路线图：第一阶段，为期6个月，我们现有的16个AD和16个NEC样本队列：目标1。研究miR-34a已知靶点可能的下调；和Aim 2。开展试点miR-34a/SIRT1 tpr指数的可行性研究；第二阶段为期两年，有200名AD和200名NEC参与者。建立PBMC-DNA、-RNA和蛋白质标本以及血清/血浆样本的生物库，用于目标2和3的检测；目标2。生成基于pbmc的miR34a/SIRT1（及其他靶标）TPR指数；和Aim 3。开展基于血清/血浆miR- 34a/SIRT1-TPR指数的可行性研究。该项目的成功将使我们能够生成基于PBMC和血清的miR-TPR指数，作为AD患者的个性化诊断，满足医疗保健的迫切需求，为疾病患者、他们的护理者和整个社会带来巨大的收益。

DESCRIPTION (provided by applicant): The present lack of blood-based diagnosis requires AD patients to be subjected to either invasive spinal fluid (CSF) tapping, expensive MRI or PET imaging, or arduous psychological testing, all unsuitable and costly for our elderly. Strategically, we shall address this unmet need by generating systemic biomarkers detectable in peripheral mononuclear cells (PBMC) and serum/plasma, focusing on two classes of molecules, micro- RNAs and their target genes, which generally exhibit an inverse relationship because the former noncoding RNA functions by partially repressing the latter"s expression as a "dimmer switch", via binding either at the co- ding region of the message, thus degrading it, or at the 3"-untranslated region, to inhibit translation. Thus, key microRNAs and their targets can serve as disease biomarkers, in "see-saw" balance, applicable for new diagnostics and/or therapy. Our pilot study with a small cohort of 16 AD and 16 age-matched normal elderly controls (NEC) revealed: 1. Predominant down-regulation of gene expression at the message level in AD PBMC; and 2. Correlated up-regulation of microRNA (miR) expression in PBMC of the same individuals. In this proposal, we focus on a specific up-regulated microRNA, miR-34a, whose known targets are SIRT1, cdk4, cdk6, cyclin E2, bcl2, etc. SIRT1 is a member of the 7-member Silent Information Regulator protein family. Caloric restriction extends longevity through triggering expression of SIRT1, which can also be mimicked by resveratrol, a red wine polyphenol. SIRT1 reduction is linked to accumulation of Tau and A242 production, two hallmarks of AD etiopathogenesis. Thus, we suggest that in AD there is a systemic effect detectable in PBMC and serum/plasma; up-regulated miR-34a may induce down-regulation of SIRT1, with attendant pathophysiologic results. In this proposal, we plan to generate for this "see-saw" of changes miR-34a/SIRT1 Target Pair Ratio (TPR) indices, to quantify both disease presence as well as progress; the indices should also provide an unprecedented evaluation of drug efficacy. This Fast-track proposal of two phases is planned with our existing small cohort study as the roadmap for the larger cohort investigation: Phase I of six months with our existing small 16 AD and 16 NEC sample cohorts to: Aim 1. study possible down-regulation of miR-34a"s known targets; and Aim 2. develop a feasibility study of pilot miR-34a/SIRT1 TPR-indices; and Phase II of two years with larger cohorts of 200 AD and 200 NEC participants: Aim 1.Establish a Bio-Repository of PBMC-DNA, -RNA & -protein specimens, and serum/plasma samples for assays in Aims 2 & 3; Aim 2. Generate PBMC-based miR34a/SIRT1 (& other targets) TPR indices; and Aim 3. Perform feasibility study to develop serum/plasma-based miR- 34a/SIRT1-TPR indices. Success of this project will allow us to generate PBMC- and serum-based miR-TPR indices as personalized diagnostics for AD victims, meeting an urgent need in health care, a huge gain for disease victims, their caregivers, and our society at large. PUBLIC HEALTH RELEVANCE: At present, the absence of any blood-based diagnosis for Alzheimer"s disease (AD) requires patients to enduring arduous neuropsychological testing, invasive cerebrospinal fluid tapping, and/or expensive MRI or PET imaging, with definitive diagnosis deferred until brain autopsy. Our preliminary findings, based on new science concerning a novel molecular species, microRNAs (miR) and their "see-saw" partial repression of the expression of their target gene(s), suggest that potential disease biomarkers for AD are detectable systemical- ly in peripheral blood mononuclear cells and/or serum/plasma, and may be quantified as miR-Target Pair Ra- tios (TPR). Our plan is to define AD-specific TPR indices, initially focusing on miR-34a and its target, SIRT1, whose reduction is known to be associated with increased Tau and A242, two hallmarks of AD etiopathogene- sis; our ultimate goal is a "Tool-Box" of TPR indices, miR-34a/SIRT1-TPR being the first such AD diagnostic, indicating not only disease presence, but also its progress (and even drug efficacy monitoring), a huge strate- gic gain for the victims of this costly disease, and our society at large!