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

描述（由申请人提供）：人微小RNA作为阿尔茨海默病的潜在治疗靶点阿尔茨海默病（AD）是老年痴呆症的最常见原因。目前的治疗仅提供适度的症状缓解，并且不能减缓疾病进展。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。AD的主要特征包括淀粉样蛋白斑块、神经元缠结、突触功能障碍和认知能力下降。这些畸变被认为部分是由于淀粉样β肽（A？）的过度产生，A？是A？前体蛋白（APP）的蛋白水解产物。参与A？生产的蛋白质的失调可能导致A？过量沉积。在这里，我们提出了一种新的方法，靶向microRNA（miRNA）的治疗干预。这些是短的非编码RNA，其通过与靶转录物的3 '-UTR中的特异性识别元件相互作用来抑制蛋白质表达。我们假设特定的miRNA种类调节APP基因产物的内源性水平，并且miRNA介导的调节的破坏将调节A？水平。Specific Aim（SA）1a将测试特异性miRNA在控制APP表达中的内源性作用。原理：我们最近发现特异性miRNA（miR-101和miR-153）在外源性递送时调节APP表达。为了证明这一途径的生理相关性，我们将通过使用miRNA抑制剂和“靶标保护剂”实验来证明这种相互作用是内源性的。影响：这种调控途径的存在将刺激对其疾病相关性的研究。它还将为限制APP/ A水平和预防AD和唐氏综合征的神经变性开辟治疗机会。SA 1b将评估miRNA与APP的调控相互作用的破坏如何影响A？稳态。基本原理：由于我们的重点是APP及其在AD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AD中涉及的下游分子途径。我们将分析APP加工的产物：APP和A？水平。影响：这些途径的调节表明这些miRNA可能具有内源性调节作用，这将使它们成为有吸引力的治疗靶点。SA 2将检查AD动物模型中miR-101和miR-153的体内过表达的作用。基本原理：上述实验将彻底评估这些miRNAs的治疗潜力。在该目的中概述的实验将直接测试miRNA在相关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靶点有望以有益的方式调节A？水平。影响：测试这将进一步验证它们作为治疗靶点的地位。重要性：拟议的实验将提供强有力的证据，无论是在外源性和内源性水平，以及在体外和体内的miRNA调节APP的表达。这些实验将解决操纵miRNA与APP转录物的相互作用是否对涉及AD的下游分子途径产生有益影响，以及这些新药物靶点用于更好的治疗剂的潜在用途。

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.