Mechanisms of motor superperformance

运动超性能的机制

• 批准号: 10701427
• 负责人: Juan M. Pascual
• 金额: $ 53.97万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-21 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10701427
• 关键词: Adenoviruses; Animals; Behavioral; Binding; Biological Assay; Brain; Cells; Cerebellum; Chemicals; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; DNA; DNA Folding; DNA Repair; Data; Dependence; Dependovirus; Disease; Embryo; Ethylnitrosourea; Fibroblasts; Future; G-Quartets; GDF8 gene; Gait; Gene Expression; Genes; Genetic; Genetic Transcription; Genomics; Goals; Health; Hippocampus (Brain); Human; Impairment; Injections; Investigation; Laboratory mice; Locomotion; Mediating; Mediation; Mediator of activation protein; Messenger RNA; Methods; Mission; Motor; Movement; Mus; Muscular Dystrophies; Mutant Strains Mice; Mutate; Mutation; Neocortex; Nervous system structure; Neurologic; Organism; Outcome; Output; Performance; Persons; Pharmaceutical Preparations; Pharmacology; Phenotype; Population; Predisposition; Prosencephalon; Purkinje Cells; Radiation; Radiation Induced DNA Damage; Regulation; Resistance; Spinal Cord; Spinal Muscular Atrophy; Stroke; Synapses; Synaptic Transmission; System; Testing; Therapeutic; Transcript; Transcriptional Regulation; United States National Institutes of Health; Up-Regulation; Video Recording; Work; antagonist; base; behavior test; cancer type; disability; drug development; experience; functional gain; gene product; loss of function; loss of function mutation; malignant breast neoplasm; man; motor disorder; motor impairment; motor learning; motor recovery; mutant; nervous system disorder; neurophysiology; novel; overexpression; protein expression; screening; stem; stroke recovery; synaptic function; transcriptome; transcriptomics; treadmill

MECHANISMS OF MOTOR SUPERPERFORMANCE: ABSTRACT Clinical experience and world population-level data indicate that most neurological disability stems from motor dysfunction. Yet, spontaneous superperformer mutations occur in a variety of species including man, illustrating that the intrinsic motor capacity of the organism can be augmented. We set out to identify similar mutations by rotarod screening of 33,806 laboratory mice harboring chemically induced random mutations with the goal of mechanistically explaining and, eventually, pharmacologically enabling the phenomenon of motor superperformance. In this context, we have discovered that a mutation in an unsuspected gene, Rif1 (Replication Timing Regulatory Factor 1), confers supernormal motor ability. Using clustered regularly interspaced short palindromic repeats (CRISPR) Rif1-mutant mice, we have determined that: 1) mutant superperformance is a selective phenotype, with distinct changes in motor features quantifiable by our novel analysis method, but no other effects upon rigorous behavioral testing, and 2) the mutation also leads to accelerated motor recovery from stroke. The superperformance mechanism, however, is unknown: although Rif1 participates in DNA repair and in transcriptional regulation via G4 folded DNA structural stabilization, little is known about its function in the nervous system. There is precedent that DNA repair may be associated to synaptic transmission strength, while DNA G4 regulation could enhance the transcription of genes active in the motor system. We have refined this hypothetical framework by identifying several consequences of the Rif1 mutation: a) Increased cerebellar Purkinje cell firing regularity and local field potential changes in the non- moving mouse, which can influence movement precision, with change of these neurophysiological parameters upon locomotion on a treadmill; b) Increased resistance to DNA-damaging radiation; c) Increased resistance to G4 stabilization; d) Overexpression of a fraction of the cerebellar (but not forebrain or spinal cord) synaptic transcriptome including potential Rif1 mutation mediators such as Kcnma1, Kif5c and Nab2; e) These transcripts may be relevant to the phenotype because we show that loss of function mutations in them degrade motor performance, whereas f) Cerebellar injection of adenovirus-containing Nab2 induces superperformance. This proposal unifies this body of work by postulating that the Rif1 mutation modifies DNA repair and/or G4 DNA folding resulting in upregulation of synaptic transcripts, with either one or both mechanisms augmenting the precision of cerebellar synapse activity relevant to movement control. To this effect, we will conduct neurophysiological studies, determine the transcriptome in single cells, alter Kcnma1, Kif5c and Nab2 expression, and investigate DNA repair and DNA G4 regulation to test which of these mechanisms enable the superperformance phenotype. Our goal is to initiate and steer the mechanistic investigation (by us or any others) of Rif1 in the brain for ultimate therapeutic gain if appropriate.

运动超表现的机制：摘要 临床经验和世界人口水平的数据表明，大多数神经疾病来自运动 功能障碍。然而，自发超级表现突变发生在包括人在内的多种物种中， 说明可以增强生物体的内在运动能力。我们着手确定类似的 通过对33,806只具有化学诱导随机突变的实验室小鼠的旋风筛查突变 机械学解释并最终在药理学上实现了电动机现象的目的 超级性能。在这种情况下，我们发现一个未使用的基因RIF1中的突变 （复制正时调节因子1），赋予超级运动能力。定期使用聚类 间隔短的短文重复序列（CRISPR）RIF1突变小鼠，我们确定：1）突变体 超级性能是一种选择性表型，我们的小说可量化电动机特征的明显变化 分析方法，但对严格的行为测试没有其他影响，2）突变也导致 从中风加速了运动恢复。但是，超性能机制尚不清楚：尽管 RIF1通过G4折叠的DNA结构稳定参与DNA修复和转录调节，很少 知道其在神经系统中的功能。先例，DNA修复可能与 突触传递强度，而DNA G4调节可以增强活性基因的转录 电机系统。我们通过确定RIF1的几个后果来完善了这个假设的框架 突变：a）小脑Purkinje细胞发射规律性和非局部场的潜在变化增加 移动的小鼠会随着这些神经生理参数的改变而影响运动精度 在跑步机上运动时； b）增加对DNA伤害辐射的阻力； c）增加对 G4稳定； d）小脑（但不是前脑或脊髓）突触的过表达 转录组，包括潜在的RIF1突变介质，例如KCNMA1，KIF5C和NAB2； e）这些 成绩单可能与表型有关，因为我们表明其功能突变损失降低 运动性能，而f）小脑注射含有腺病毒的NAB2的运动诱导超级表现。 该提案通过假设RIF1突变修改DNA修复和/或G4来统一这项工作 DNA折叠导致突触转录物上调，一种或两种机制增加 小脑突触活动的精度与运动控制有关。为此，我们将进行 神经生理研究，确定单细胞中的转录组，改变KCNMA1，KIF5C和NAB2 表达并研究DNA修复和DNA G4调节以测试这些机制中的哪种 超表现表型。我们的目标是启动和引导机械调查（我们或任何人 其他）RIF1在大脑中，如果适当的话，可以实现最终的治疗收益。

项目成果

Genetic influences on motor learning and superperformance mutants revealed by random mutational survey of mouse locomotion.

通过对小鼠运动的随机突变调查揭示了遗传对运动学习和超性能突变体的影响。

• DOI: 10.1101/2023.06.28.546756
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Jakkamsetti,Vikram;Ma,Qian;Angulo,Gustavo;Scudder,William;Beutler,Bruce;Pascual,JuanM
• 通讯作者: Pascual,JuanM