Functional Studies of Variants of the Bipolar Risk Gene CACNA1C in Human Neurons

人类神经元中双向情感障碍风险基因 CACNA1C 变体的功能研究

基本信息

批准号：
8430108
负责人：
Jen Qian Pan
金额：
$ 25.95万
依托单位：
BROAD INSTITUTE, INC.
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-25 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8430108
关键词：
12p13 Address Adoption Adverse effects Affect Alleles Animals Behavioral Biochemical Biological Models Bipolar Disorder Brain Brain Diseases Brain imaging Calcium Calcium Channel Cell Line Cell Survival Cell membrane Cell physiology Cells Chemicals Chromosomes, Human, Pair 12 Chronic Code Complex Data Disease Drug Delivery Systems Ectopic Expression Engineering Exons Exploratory/Developmental Grant Family Fibroblasts Functional RNA Functional disorder Future Gene Expression Genes Genetic Genetic Polymorphism Genetic Risk Genetic Variation Genome Genomics Genotype Haplotypes Heart Hereditary Disease Human Hypertension Impaired cognition In Vitro Individual Introns L-Type Calcium Channels L-type calcium channel alpha(1C)Lead Life Link Lithium Major Depressive Disorder Manic Mental Depression Mental disorders Meta-Analysis Modeling Molecular Mood Disorders Mus Muscle Contraction Mutation Neurons Organ Patch-Clamp Techniques Patients Phenotype Play Population Predisposition Prevalence Process Recurrence Research Personnel Risk Role Sampling Schizophrenia Second Messenger Systems Signal Transduction Single Nucleotide Polymorphism Site Susceptibility Gene Synapses Techniques Technology Testing Time Timothy syndrome Transcription Coactivator Twin Multiple Birth United States Variant Wit Work base cell growth cohort density disorder risk gain of function genome wide association study genome-wide high risk human ASCL1 protein human disease insight neurotransmitter release novel novel therapeutics nuclease painful neuropathy psychogenetics second messenger severe mental illness tool transcription factor valproate voltage

项目摘要

DESCRIPTION (provided by applicant): This is a new R21 application to study in live human neurons the function of a bipolar disorder susceptibility gene encoding a neuronal calcium channel. Calcium ion channels are expressed in all excitable and many non-excitable cells to transduce electric signals at the cell membrane into chemical potentials of calcium influx. Calcium is a second messenger whose intracellular concentration controls many cellular functions including muscle contraction, neurotransmitter release, cell survival and growth. Calcium ion channels are important drug targets for hypertension and neuropathic pain. Coding mutations in the CACNA1C calcium ion channel gene cause a rare hereditary disorder called Timothy Syndrome, affecting the heart, the brain, and other organs. Bipolar disorder is a chronic and severe mental illness with 1-2% lifetime prevalence in population of the United States. Individuals with bipolar disorder suffer from recurrent episodes of mania and depression, and current bipolar treatments, such as lithium, are often ineffective in many patients. Treatment options for bipolar disorder are unlikely to advance substantially until the underlying molecular processes in pathogenic risk are better understood. There is a clear heritable risk in bipolar disorder, but it has been difficult to establish clear risk associations in any particular gene wit bipolar disorder. Large-scale genome-wide association studies in three independent cohorts and a large meta-analysis have revealed a strong and consistent association between bipolar disorder susceptibility and a genomic locus on chromosome 12 in the CACNA1C gene. Interestingly, the same genomic region was found to be associated with schizophrenia and major depression susceptibility last year, making it one of the most replicable and consistent associations in psychiatric genetics. These exciting genetic discoveries present unique opportunities to study how genomic variations in the CACNA1C gene may influence neuronal calcium channel activity. Recently, mouse and human fibroblasts have been directly converted to functional neuronal cells through ectopic expression of three transcription factors (ASCL1, MYT1L, BRN2). This technological breakthrough makes human-specific in vitro neuronal models possible. Transcription activator-like effector nuclease (TALEN) technology is a molecular engineering tool that recognizes unique sequences in a genomic locus, introduces site-specific changes in the native genome, and helps elucidate genotype-phenotype relationships in an isogenic background. We will use genome editing, together with a combination of gene expression, biochemical, and electrophysiological analyses, to reveal the functional role of intronic single nucleotide polymorphism (SNP) variations of CACNA1C in controlling L-type calcium channel activity in human induced neurons. Our work has the potential to provide novel insights into the molecular mechanism of a genetic risk locus for psychiatric illness and to validate a systematic approach to study the functional consequences of genetic variations in complex brain disorders. PUBLIC HEALTH RELEVANCE: This R21 proposal will test the hypothesis that the CACNA1C gene peak SNP associated haplotype, implicated in susceptibility to bipolar disorder, regulates Cav1.2 calcium channel function in human induced neurons. We will use reprogramming and genome editing, together with a combination of gene expression, biochemical, and electrophysiological analyses, to reveal the functional role of intronic variations of CACNA1C in controlling L- type calcium channel activity in human induced neurons.

描述（由申请人提供）：这是一个新的 R21 应用，用于在活体人类神经元中研究编码神经元钙通道的双相情感障碍易感基因的功能。钙离子通道在所有可兴奋和许多非兴奋细胞中表达，将细胞膜上的电信号转换为钙流入的化学势。钙是第二信使，其细胞内浓度控制许多细胞功能，包括肌肉收缩、神经递质释放、细胞存活和生长。钙离子通道是高血压和神经性疼痛的重要药物靶点。 CACNA1C 钙离子通道基因的编码突变会导致一种罕见的遗传性疾病，称为蒂莫西综合症，影响心脏、大脑和其他器官。双相情感障碍是一种慢性且严重的精神疾病，在美国人口中一生患病率为 1-2%。双相情感障碍患者会反复发作躁狂症和抑郁症，目前的双相情感障碍治疗方法（例如锂盐）对许多患者往往无效。在更好地了解致病风险的潜在分子过程之前，双相情感障碍的治疗方案不太可能取得实质性进展。双相情感障碍存在明显的遗传风险，但很难在任何特定基因与双相情感障碍之间建立明确的风险关联。三个独立队列的大规模全基因组关联研究和大型荟萃分析揭示了双相情感障碍易感性与 CACNA1C 基因 12 号染色体上的基因组位点之间存在强烈且一致的关联。有趣的是，去年发现同一基因组区域与精神分裂症和重度抑郁症易感性相关，使其成为精神遗传学中最可复制和一致的关联之一。这些令人兴奋的基因发现为研究 CACNA1C 基因的基因组变异如何影响神经元钙通道活性提供了独特的机会。最近，小鼠和人类成纤维细胞通过三种转录因子（ASCL1、MYT1L、BRN2）的异位表达直接转化为功能性神经元细胞。这一技术突破使得人类特异性体外神经元模型成为可能。类转录激活因子效应核酸酶 (TALEN) 技术是一种分子工程工具，可识别基因组位点中的独特序列，在天然基因组中引入位点特异性变化，并有助于阐明等基因背景中的基因型-表型关系。我们将利用基因组编辑，结合基因表达、生化和电生理学分析，揭示 CACNA1C 内含子单核苷酸多态性 (SNP) 变异在控制人类诱导神经元中 L 型钙通道活性中的功能作用。我们的工作有可能为精神疾病遗传风险位点的分子机制提供新的见解，并验证一种系统方法来研究复杂脑部疾病中遗传变异的功能后果。公共健康相关性：该 R21 提案将检验以下假设：CACNA1C 基因峰值 SNP 相关单倍型（与双相情感障碍的易感性有关）调节人类诱导神经元中的 Cav1.2 钙通道功能。我们将利用重编程和基因组编辑，结合基因表达、生化和电生理学分析，揭示 CACNA1C 内含子变异在控制人类诱导神经元中 L 型钙通道活性中的功能作用。