miR132 regulation of neuronal plasticity, learning, and memory

miR132 对神经元可塑性、学习和记忆的调节

• 批准号: 8335010
• 负责人: Katelin L.F. Hansen
• 金额: $ 3.57万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2014-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8335010
• 关键词: 3' Untranslated Regions; Adult; Affect; Alzheimer' s Disease; Behavioral; Behavioral Paradigm; Bioinformatics; Biological; CREB1 gene; Cell Culture Techniques; Cells; Code; Cognition; Cognitive; Cognitive deficits; Data; Dendrites; Development; Developmental Process; Disease; Doxycycline; Exposure to; Fluorescent in Situ Hybridization; Functional RNA; Gene Expression; Gene Expression Profile; Genetic Transcription; Genetic Translation; Hippocampus (Brain); Huntington Disease; Immunofluorescence Immunologic; Immunolabeling Technics; Impaired cognition; In Situ Hybridization; In Vitro; Label; Lead; Learning; Memory; Memory impairment; Mental disorders; Messenger RNA; MicroRNAs; Molecular; Molecular Target; Morphogenesis; Morphology; Mouse Strains; Mus; Nature; Nervous System Physiology; Nervous system structure; Neuronal Plasticity; Neurons; Nucleotides; Output; Pattern; Performance; Phenocopy; Phenotype; Plastics; Play; Population; Process; Prosencephalon; Publishing; RNA Binding; RNA-Induced Silencing Complex; Regulation; Research; Rett Syndrome; Role; Schizophrenia; Seeds; Signal Transduction; Signaling Molecule; Stem cells; Sum; Synaptic plasticity; Techniques; Testing; Tetanus Helper Peptide; Tetracycline Control; Tetracyclines; Tissues; Transcript; Transgenes; Transgenic Mice; Transgenic Model; Transgenic Organisms; Untranslated RNA; Vertebral column; Work; base; cognitive enhancement; density; dentate gyrus; drinking water; environmental enrichment for laboratory animals; gene induction; in vivo; interest; memory recognition; mouse model; novel therapeutics; promoter; research study; response; transgene expression; treatment strategy

Inducible gene expression plays a central role in neuronal plasticity, learning, and memory. Dysregulation of these processes can lead to severe neuronal disorders and cognitive impairment. In addition to coding transcripts (mRNAs), non-coding microRNA (miRNAs) appear to play a regulatory role in the neuronal plasticity. miRNAs are small, evolutionarily-conserved signaling molecules that act as silencing regulators of mRNA targets. Disruption of miRNA expression and signaling is associated with severe cognitive impairment. Thus, the functional role of miRNAs in nervous system physiology and cognition merits close examination. This proposal focuses on the CREB-regulated miRNA132 (miR132), which has been shown to be expressed in an activity-dependant manner in vitro and in vivo. Altered miR132 is associated with several psychiatric (schizophrenia) and degenerative (Huntington's disease) disorders of the nervous system. Recently, my published work using a miR132 transgenic mouse strain revealed that miR132 significantly regulates hippocampal dendrite spinogenesis in vivo, as well as recognition memory. However, the details of miR132's molecular regulation and its behavioral consequences remain unclear. I hypothesize that miR132 is expressed in mature and developing neurons throughout the hippocampus, and its inducible expression is required for normal memory formation. As an extension of this idea, I further propose that miR132 levels (both basal and inducible) must be tightly controlled, and that deviation from this range will result in cognitive deficits. Here, I propose a strategy to assess the hippocampal expression of miR132, to explore its behavioral/cognitive consequences and to profile a subset of its putative molecular (mRNA) targets. To this end, Aim 1 will utilize in situ hybridization and immunolabeling techniques to examine basal miR132 expression patterns within the hippocampus, as well as profile its inducible expression following environmental enrichment and learning paradigms. In Aim 2, I will employ the noted tetracycline-regulated transgenic mouse strain (tTA:miR132) that expresses miR132 in forebrain neurons to explore the contribution of miR132 to learning and memory. To this end, I will initially profile cognitive consequences of tonic transgenic miR132 expression. I will then examine whether the miR132 learning phenotype is plastic in nature, or whether it is fixed (i.e. a permanent cognitive deficit) by taking advantage of the tetracycline-controlled promoter to shut down transcription of the transgenic miR132. Finally, although I have shown that tonically high levels of transgenic miR132 impair learning, I hypothesize that there exists an optimized level of miR132 expression that facilitates cognitive performance. This idea will be tested in experiments which will titer transgenic miR132 (using doxycycline) to parallel the level observed following environmental enrichment, in an attempt to phenocopy cognitive enhancement resulting environmental enrichment. Finally, Aim 3 proposes to use the Solexa Deep Sequencing technique to profile downstream targets of miR132 in the tTA:miR132 mouse strain. Further, a small subset of these targets (5 in total) will be validated using molecular and histological approaches. In sum, a more complete understanding of miR132's role in neuronal signaling and cognition should further our efforts to develop novel therapeutic strategies for the treatment of a variety of mental disorders.

可诱导的基因表达在神经元的可塑性、学习和记忆中起着核心作用。这些过程的失调可能会导致严重的神经元紊乱和认知障碍。除了编码转录本(MRNAs)，非编码microRNA(MiRNAs)似乎在神经元可塑性中发挥调节作用。MiRNAs是一种进化上保守的小信号分子，可以作为mRNA靶标的沉默调节器。MiRNA表达和信号的中断与严重的认知障碍有关。因此，miRNAs在神经系统生理和认知中的功能作用值得仔细研究。这个建议集中在CREB调节的miRNA132(MiR132)，它已被证明在体外和体内以活性依赖的方式表达。改变的miR132与几种精神疾病(精神分裂症)和退行性神经系统疾病(亨廷顿病)有关。最近，我使用miR132转基因小鼠品系发表的工作显示，miR132在体内显著调节海马树突棘的发生，以及识别记忆。然而，miR132‘S的分子调控及其行为后果的细节仍不清楚。我假设miR132在整个海马区成熟和发育中的神经元中都有表达，它的诱导表达是正常记忆形成所必需的。作为这一想法的延伸，我进一步提出，miR132水平(基础和可诱导的)必须受到严格控制，偏离这个范围将导致认知缺陷。在这里，我提出了一种策略，以评估miR132在海马区的表达，探索其行为/认知后果，并描述其可能的分子(MRNA)靶点的子集。为此，AIM 1将利用原位杂交和免疫标记技术来检测海马区基本的miR132表达模式，并描述其在环境丰富和学习范式下的诱导表达。在目标2中，我将使用著名的四环素调控的转基因小鼠品系(TTA：miR132)，该品系在前脑神经元中表达miR132，以探索miR132对学习和记忆的贡献。为此，我将首先概述紧张性转基因miR132表达的认知后果。然后，我将检查miR132学习表型本质上是可塑性的，还是通过利用四环素控制的启动子关闭转基因miR132的转录来固定的(即永久性认知缺陷)。最后，虽然我已经证明了高水平的转基因miR132会损害学习，但我假设存在一个促进认知表现的miR132表达的优化水平。这一想法将在实验中得到验证，该实验将滴定转基因miR132(使用多西环素)，使其与环境浓缩后观察到的水平平行，以尝试通过环境浓缩来提高表观认知能力。最后，Aim 3建议使用Solexa深度测序技术来分析TTA：miR132小鼠品系中miR132的下游靶标。此外，这些靶点中的一小部分(总共5个)将使用分子和组织学方法进行验证。总之，更全面地了解miR132的S在神经元信号和认知中的作用将有助于我们努力开发治疗各种精神障碍的新治疗策略。