Reversing BDNF Impairments in Rett Mice with TRPC Channel Activators

使用 TRPC 通道激活剂逆转 Rett 小鼠的 BDNF 损伤

基本信息

批准号：
8458289
负责人：
Lucas D Pozzo-Miller
金额：
$ 25.64万
依托单位：
UNIVERSITY OF ALABAMA AT BIRMINGHAM
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-06-10 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8458289
关键词：
Acute Autistic Disorder Binding Biochemical Biological Assay Birth Brain Brain-Derived Neurotrophic Factor Breeding Cells Childhood Clinical Data Coupled DNA-Binding Proteins Dendritic Spines Development Electrophysiology (science)Epilepsy Equilibrium Evaluation Excitatory Amino Acid Antagonists Family Functional disorder GABA Receptor Genes Genetic Transcription Genotype Hippocampus (Brain)Hyperactive behavior Image Immunoglobulin G Impairment Individual Intellectual functioning disability Interneurons Intervention Link Measures Mediating Membrane Messenger RNA Methyl-CpG-Binding Protein 2 Molecular Monitor Mus Mutant Strains Mice Mutation Neurodevelopmental Disorder Neurons Neurotrophic Tyrosine Kinase Receptor Type 2 Pharmacological Treatment Phenotype Promoter Regions Proteins Pyramidal Cells Recombinants Research Rett Syndrome Signal Transduction Site Slice Societies Testing Therapeutic Therapeutic Agents Water analog autism spectrum disorder base design direct application disability granule cell hippocampal pyramidal neuron hyperforin inhibitor/antagonist loss of function loss of function mutation male member mossy fiber mouse model mutant neuropathology neurotrophic factor novel pre-clinical preclinical study presynaptic public health relevance receptor research study response small hairpin RNA therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Understanding the pathophysiological mechanisms of Rett syndrome (RTT) at the cellular and molecular levels, and establishing successful bioassays for evaluation of potential therapeutic strategies take priority in the path of research on this neurodevelopmental disorder. RTT, an autism spectrum disorder, is a devastating childhood disability due to its impact on individuals (1:10,000 births worldwide), their families and society RTT is caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2), a transcriptional regulator that binds to methylated CpG sites in promoter regions of several genes, including the neurotrophin Bdnf, and the Ca2+-permeable non-selective cationic channel subunits Trpc3 and Trpc6. The availability of endogenously expressed BDNF for its activity-dependent release can be monitored with membrane currents and dendritic Ca2+ signals mediated by TRPC channels. Preliminary Results demonstrate that TRPC currents and Ca2+ signals evoked in CA3 pyramidal neurons by stimulation of presynaptic mossy fiber (MF) are smaller in symptomatic Mecp2 mutant mice. Responses evoked by either recombinant BDNF or a non-hydrolyzable DAG analog (to activate TRPC channels) are also impaired in Mecp2 mutant neurons. Consistently, mRNA and protein levels of both BDNF and TRPC3 are lower in Mecp2 mutant hippocampus. Preliminary Results show that the TRPC6 channel activator hyperforin evokes membrane currents and Ca2+ signals, and promotes dendritic spine maturation in CA3 pyramidal neurons, resembling well-known actions of BDNF. Based on these Preliminary Results and since TRPC3 and TRPC6 form heteromultimers, our hypothesis is that impaired BDNF signaling through TRPC3/6 channels in Mecp2 mutant mice can be overcome by treatment with the selective TRPC6 activator hyperforin to reverse two RTT-like phenotypes: hippocampal network hyperactivity and immature dendritic spines. We propose two Specific Aims: 1. Test whether membrane currents and Ca2+ signals evoked by BDNF and mediated by TRPC channels in CA3 pyramidal neurons and GABAergic interneurons are impaired in Mecp2 mutant mice; and 2. Test whether treatment with hyperforin reverses hippocampal phenotypes in Mecp2 mutant mice, i.e. hippocampal network hyperactivity and immature dendritic spines. Identifying TRPC3/6 channels as novel targets for pharmacological intervention is necessary for pre-clinical trials leading to rational treatments for RTT and other neurodevelopmental disorders associated with MECP2 mutations and impaired BDNF signaling.

描述（由申请人提供）：了解RETT综合征（RTT）在细胞和分子水平上的病理生理机制，并建立成功的生物测定法以评估潜在的治疗策略，在研究这种神经发育障碍的研究中优先考虑。 RTT是一种自闭症谱系障碍，是一种毁灭性的儿童残疾，由于其对个体的影响（全球1：10,000个出生），其家庭和社会RTT是由编码甲基-CPG结合蛋白2（MECP2）的基因的功能丧失突变引起的BDNF和Ca2+可渗透的非选择性阳离子通道亚基TRPC3和TRPC6。可以用TRPC通道介导的膜电流和树突状CA2+信号来监测内源表达的BDNF的活性依赖性释放的可用性。初步结果表明，通过刺激突触前苔藓纤维（MF），在CA3锥体神经元中引起的TRPC电流和CA2+信号在有症状的MECP2突变小鼠中较小。在MECP2突变神经元中，重组BDNF或不可用的DAG类似物（激活TRPC通道）引起的响应也受损。始终如一，在MECP2突变体海马中，BDNF和TRPC3的mRNA和蛋白质水平都较低。初步结果表明，TRPC6通道激活剂Hyperforin唤起膜电流和Ca2+信号，并促进CA3锥体神经元中的树突状脊柱成熟，类似于BDNF的知名作用。 Based on these Preliminary Results and since TRPC3 and TRPC6 form heteromultimers, our hypothesis is that impaired BDNF signaling through TRPC3/6 channels in Mecp2 mutant mice can be overcome by treatment with the selective TRPC6 activator hyperforin to reverse two RTT-like phenotypes: hippocampal network hyperactivity and immature dendritic spines.我们提出了两个具体的目的：1。测试BDNF引起的膜电流和Ca2+信号是否在MECP2突变小鼠中受到了CA3锥体神经元和GABAergic INTRERORS中的TRPC通道和GABAergic INTRERORS介导的； 2。测试用超福林治疗是否逆转MECP2突变小鼠的海马表型，即海马网络过度活跃和未成熟的树突状棘。对于临床前试验，必须将TRPC3/6通道确定为药理学干预的新靶标，这是导致与MECP2突变和BDNF信号受损的RTT和其他神经发育障碍合理治疗的合理治疗。