Human MicroRNA as a potential therapeutic target in Alzheimer's disease.

描述(申请人提供)：人类microRNA作为阿尔茨海默病的潜在治疗靶点阿尔茨海默病(AD)是老年人痴呆症最常见的原因。目前的治疗方法只能提供适度的症状缓解，并不能减缓疾病的进展。因此，需要新的治疗策略。我们建议识别和验证一类新的药物靶点的成员。阿尔茨海默病的主要特征包括淀粉样斑块、神经纤维缠结、突触功能障碍和认知能力下降。这些异常被认为在一定程度上是由于淀粉样β蛋白(A？)的过度产生，A？是A？前体蛋白(APP)的蛋白分解产物。参与A？产生的蛋白质的失调可能会导致A？的过度沉积。在这里，我们提出了一种新的靶向microRNA(MiRNA)的治疗干预方法。这些是短的、非编码的RNA，通过与TARGE转录本的3‘-UTR中的特定识别元件相互作用来抑制蛋白质的表达。我们假设特定的miRNA物种调节APP基因产物的内源性水平，并且miRNA介导的调节的中断将调节A？水平。特定目的(SA)1a将测试特定miRNAs在调控APP表达中的内源性作用。原理：我们最近发现，当外源递送时，特定的miRNA(miR-101和miR-153)调节APP的表达。为了证明这一途径的生理学相关性，我们将通过使用miRNA抑制剂和“靶标保护器”实验来证明这种相互作用是内源性发生的。影响：这种调控途径的存在将促进对其与疾病相关性的研究。它还将打开治疗机会，限制APP/A水平，防止AD和唐氏综合症的神经退行性变。SA1b将评估miRNA与APP调控相互作用的中断如何影响A？动态平衡。基本原理：由于我们的重点是APP及其在A？中的作用，我们将研究内源性miRNA-3‘-UTR调控相互作用的操纵如何影响与AD有关的下游分子通路。我们将对APP加工的产品进行检测：APP和A？级。影响：这些通路的调节将表明这些miRNAs可能具有内源性调节作用，使其成为有吸引力的治疗靶点。SA 2将在AD动物模型中检测体内过表达miR-101和miR-153的影响。基本原理：上面概述的实验将彻底评估这些miRNAs的治疗潜力。这一目标中概述的实验将直接测试这些miRNA在相关的AD体内模型中用于治疗调节的临床前适用性。一个合适的miRNA靶标有望以一种有益的方式调节A？水平。影响：检测这一点将进一步证实他们作为治疗靶点的地位。意义：拟议的实验应该为miRNA是否在外源和内源水平以及在体外和体内调节APP的表达提供强有力的证据。这些实验将研究操纵miRNA与APP转录本的相互作用是否对AD所涉及的下游分子通路产生有益的影响，以及这些新的药物靶点作为更好的治疗剂的潜在用途。 公共卫生相关性：阿尔茨海默病(AD)是导致老年人痴呆的最常见原因；然而，目前的治疗方法只能起到适度的症状缓解作用，并不能减缓疾病的进展。在这里，我们建议研究新的机制来调节由microRNA(MiRNA)介导的淀粉样前体蛋白(APP)，miRNA是一种短的、非编码的RNA，通常通过抑制消息RNA的翻译来调节蛋白质水平。这项提议的意义在于，miRNA对APP的调控代表了一种降低AD大脑中有毒A肽水平的新策略，拟议的工作将识别和验证一类新的药物靶点成员，这项工作的影响将是最终使用这些新的药物靶点来生产更好的治疗剂来减缓或逆转AD的疾病进展。

DESCRIPTION (provided by applicant): Human MicroRNA as a potential therapeutic target in Alzheimer's disease Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Current treatments provide only modest symptomatic relief and do not slow disease progression. Thus, new therapeutic strategies are needed. We propose to identify and validate members of a new class of drug targets. Major hallmarks of AD include amyloid plaques, neurofibrillary tangles, synaptic dysfunction and cognitive decline. These aberrations are believed to result, in part, from the overproduction of amyloid-beta peptide (A¿), a proteolytic product of the A¿ precursor protein (APP). Dysregulation of proteins involved in A¿ production may contribute to excess A¿ deposition. Here, we propose the novel approach of targeting microRNA (miRNA) for therapeutic intervention. These are short, non-coding RNAs that act to inhibit protein expression by interacting with specific recognition elements in the 3'-UTR of targe transcripts. We hypothesize that specific miRNA species regulate endogenous levels of APP gene products and that disruption of miRNA-mediated regulation will modulate A¿ levels. Specific Aim (SA) 1a will test the endogenous role of specific miRNAs in governing expression of APP. Rationale: We have recently discovered that specific miRNA (miR-101 and miR-153) regulate APP expression when delivered exogenously. To demonstrate the physiological relevance of this pathway, we will show that such interactions occur endogenously by using miRNA inhibitors and 'Target protector' experiments. Impact: Existence of such a regulatory pathway will stimulate research on its disease relevance. It will also open up therapeutic opportunities to limit APP/ A¿ levels and prevent neurodegeneration in AD and Down syndrome. SA1b will assess how disruption of miRNA regulatory interactions with APP affects A¿ homeostasis. Rationale: Since our focus is on APP and its role in A¿, we will examine how manipulation of endogenous miRNA-3'-UTR regulatory interactions affects downstream molecular pathways implicated in AD. We will assay the products of APP processing: APP and A¿ levels. Impact: Modulation of these pathways would indicate that these miRNAs likely have endogenous regulatory roles that would make them attractive therapeutic targets. SA 2 will examine the effects of in vivo overexpression of miR-101 and miR-153 in an AD animal model. Rationale: Experiments outlined above will thoroughly assess the therapeutic potential of these miRNAs. The experiments outlined in this aim will directly test the preclinical suitability of thes miRNA for therapeutic modulation in relevant AD in vivo models. A suitable miRNA target would be expected to modulate A¿ levels in a salutary fashion. Impact: Testing this will lend further validity to their status as therapeutic targets. Significance: The proposed experiments should provide strong evidence as to whether miRNA regulate APP expression at the exogenous and endogenous level, as well as in vitro and in vivo. These experiments will address whether manipulating the interactions of miRNA with the APP transcript produce salutary effects on downstream molecular pathways implicated in AD, and a potential use of these new drug targets for better therapeutic agents. PUBLIC HEALTH RELEVANCE: Alzheimer's disease (AD) is the most common cause of dementia in the elderly; however, current treatments provide only modest symptomatic relief and do not slow disease progression. Here, we propose to study novel mechanisms to regulate amyloid-¿ (A¿) precursor protein (APP) mediated by microRNA (miRNA), which are short, non-coding RNAs that typically regulate protein levels by inhibiting translation of message RNA. The significance of this proposal is that miRNA regulation of APP represents a novel strategy to reduce the toxic A¿ peptide levels in the AD brain, and the proposed work will identify and validate members of a new class of drug targets, and the impact of this work will be in the eventual use of these new drug targets to produce better therapeutic agents to slow or reverse disease progression in AD.