Neuroprotective microRNA pathways

神经保护性 microRNA 通路

• 批准号: 8687778
• 负责人: Scott E Counts
• 金额: $ 21.76万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8687778
• 关键词: Address; Affect; Alzheimer' s Disease; Amyloid; Area; Autopsy; Behavior; Biochemical; Biological Markers; Brain; Brodmann' s area; Cell physiology; Cells; Cellular Stress; Cerebellum; Cognitive; Complex; Consultations; Data; Databases; Deacetylase; Dementia; Development; Disease; Disease Progression; Down-Regulation; Energy Metabolism; Enzymes; Family; Family member; Fluorescent in Situ Hybridization; Functional RNA; Gene Expression Regulation; Generations; Genes; Harvest; Human; Immunoblotting; Immunohistochemistry; Immunoprecipitation; Impaired cognition; In Vitro; Inferior; Knowledge; Mediating; Messenger RNA; MicroRNAs; Modeling; Modification; Molecular; Neurodegenerative Disorders; Neurologic; Neurons; Onset of illness; Pathogenesis; Pathway interactions; Physiological; Physiology; Pilot Projects; Process; Proteins; RNA; Regulation; Role; Sampling; Senile Plaques; Small Interfering RNA; Specificity; Staging; Synaptic plasticity; Temporal Lobe; Testing; Therapeutic; Tissue Harvesting; Tissues; Toxic effect; Transcript; Up-Regulation; amyloid pathology; base; beta-site APP cleaving enzyme 1; biological adaptation to stress; clinical Diagnosis; drug discovery; forkhead protein; frontal lobe; human tissue; in vitro Assay; infancy; inhibitor/antagonist; innovation; insight; internal control; knock-down; mRNA Stability; mild cognitive impairment; neurogenesis; neuroprotection; new therapeutic target; novel; protein expression; research study; response; secretase

DESCRIPTION (provided by applicant): The presence of small non-coding microRNAs (miRNAs) which regulate mRNA stability has become increasingly appreciated as a critical factor in fine-tuning specific neuronal protein levels to mediate diverse brain functions. This widespread influence of miRNA regulation on neuronal physiology suggests that perturbations in miRNA function are involved in the pathogenesis of complex neurodegenerative disorders such as Alzheimer's disease (AD). However, despite initial insights that miRNAs contribute to amyloid pathology during disease progression, the field remains in its infancy and must expand to focus on identifying key multifarious miRNA network changes occurring during the onset of AD which will drive novel therapeutic targets. In particular, whether miRNA networks are dysregulated in the brains of people in the prodromal stages of AD such as amnestic mild cognitive impairment (aMCI) and the extent to which these changes have physiologic consequences for AD progression remain underexplored. To this end, our preliminary microarray and quantitative PCR (qPCR) studies discovered two families of miRNAs, miR-212/132 and miR-23a/b, that were down-regulated in the frontal cortex of aMCI subjects compared to controls. Human miRNA databases revealed that the down-regulation of either miR-212/132 or miR-23a/b was predicted to up-regulate two targets that interact to mediate neuroprotective cell stress responses, the deacetylase sirtuin 1 (sirt1) and the forkhead transcription factor foxo3a; pilot qPCR studies using the same frontal cortex samples revealed that both sirt1 and foxo3a mRNA levels were higher in aMCI compared to controls. Given the relatively delayed involvement of frontal cortex in AD pathogenesis and the ability of this region to respond to the onset of dementia by neuronal reorganization, these data suggest that miRNA-mediated up-regulation of the sirt1/foxo3a pathway represents a compensatory neuroprotective response to mounting disease. In fact, qPCR analysis performed on temporal cortex, an area affected early in the progression of AD, showed no changes in miR-212, miR-23a, sirt1, or foxo3a transcripts in the aMCI subjects. Moreover, pilot in vitro mechanistic studies showed that the coordinated down-regulation of miR-212 and miR-23a increased Sirt1 and Foxo3a protein expression and provided neuroprotection from ¿-amyloid toxicity in human neuronal cells. Hence, our preliminary data suggest that we have uncovered a novel miRNA-mediated neuroprotective pathway activated during prodromal AD. This proposal will test this hypothesis using human tissue molecular, biochemical, and histochemical approaches as well as mechanistic pathway modeling in human neurons. These studies may reveal new insights into gene regulation pathways leading to innovative therapeutic avenues for modifying AD progression.

描述（由申请人提供）：调节mRNA稳定性的小非编码microrna （mirna）的存在越来越被认为是微调特定神经元蛋白水平以介导多种脑功能的关键因素。miRNA调控对神经元生理的广泛影响表明，miRNA功能的扰动参与了复杂神经退行性疾病（如阿尔茨海默病（AD））的发病机制。然而，尽管最初的见解认为miRNA在疾病进展过程中有助于淀粉样蛋白病理，但该领域仍处于起步阶段，必须扩展到专注于识别AD发病期间发生的关键多种miRNA网络变化，这将推动新的治疗靶点。特别是，在阿尔茨海默病的前驱阶段，如遗忘性轻度认知障碍（aMCI），人们的大脑中是否存在miRNA网络失调，以及这些变化在多大程度上对阿尔茨海默病的进展产生生理后果，这些问题仍未得到充分探讨。为此，我们的初步微阵列和定量PCR （qPCR）研究发现，与对照组相比，aMCI受试者额叶皮层中miR-212/132和miR-23a/b两个mirna家族下调。人类miRNA数据库显示，miR-212/132或miR-23a/b的下调预计会上调两个相互作用介导神经保护性细胞应激反应的靶标，即去乙酰化酶sirtuin 1 （sirt1）和叉头转录因子foxo3a；使用相同额叶皮层样本的先导qPCR研究显示，与对照组相比，aMCI中的sirt1和foxo3a mRNA水平更高。考虑到额叶皮层在AD发病中的相对延迟参与以及该区域通过神经元重组对痴呆发病的反应能力，这些数据表明，mirna介导的sirt1/foxo3a通路上调代表了对日益严重的疾病的代偿性神经保护反应。事实上，在AD进展早期受影响的颞叶皮层上进行的qPCR分析显示，aMCI受试者中miR-212、miR-23a、sirt1或foxo3a转录本没有变化。此外，前期体外机制研究表明，miR-212和miR-23a的协同下调增加了Sirt1和Foxo3a蛋白的表达，并在人类神经元细胞中提供了对¿-淀粉样蛋白毒性的神经保护。因此，我们的初步数据表明，我们已经发现了一种新的mirna介导的神经保护途径，该途径在AD前驱期被激活。本提案将使用人体组织分子、生化和组织化学方法以及人类神经元的机制通路建模来验证这一假设。这些研究可能揭示基因调控途径的新见解，从而导致改变AD进展的创新治疗途径。