Roles of Gsx factors in basal ganglia development

Gsx 因子在基底神经节发育中的作用

基本信息

批准号：
10339513
负责人：
KENNETH J CAMPBELL
金额：
$ 62.37万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-01 至 2026-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10339513
关键词：
Alleles Amino Acids Anatomic Models Anatomy Anterior Attention deficit hyperactivity disorder Basal Ganglia Behavioral Binding Binding Sites Biochemical Biochemistry Bioinformatics Biological Assay Brain Cell Culture Techniques Cell Nucleus Child Childhood Neurological Disorder Cognition Corpus striatum structure Coupled DNA DNA Binding DNA-Binding Proteins Data Data Set Development Disease Dorsal Dystonia Electrophoretic Mobility Shift Assay Elements Embryo Enhancers Exhibits Functional disorder Ganglia Gene Activation Gene Expression Gene Expression Profiling Gene Expression Regulation Genes Genetic Genetic Enhancer Element Genetic Transcription Genomic approach Genomics Gilles de la Tourette syndrome Goals Grant Histologic Human Image In Vitro Intellectual functioning disability Interneurons Lateral Magnetic Resonance Imaging Maps Mediating Modeling Molecular Morphology Movement Mus Neurologic Symptoms Neuronal Differentiation Neurons Nonsense Codon Obsessive-Compulsive Disorder Outcome Pathologic Patients Pattern Phenotype Play Process Prosencephalon Proteins Publishing Regulation Regulator Genes Regulatory Element Reporter Repression Research Resolution Role Site Specificity Symptoms System Telencephalon Testing Transcriptional Regulation Variant Work behavioral phenotyping cell type dimer functional genomics genetic variant homeodomain human embryonic stem cell in vivo insight monomer mouse genetics mouse model mutant nerve stem cell neural circuit neural patterning neurogenesis novel olfactory bulb postnatal progenitor transcription factor transcriptome sequencing

项目摘要

Normal brain function relies on the correct assembly of neural circuits during development. This process starts with the patterning of neural progenitors along the dorsal-ventral and anterior-posterior axes to give rise to distinct subtypes of neurons. A number of key transcription factors (TFs) control the process of neuronal subtype specification. Work in the mouse has shown that the homeodomain (HD) TF Gsx2 plays essential roles in the patterning and differentiation of neuronal cell types that arise from progenitors in the lateral ganglionic eminence (LGE) of the embryonic mouse telencephalon. These progenitors give rise to cell types that include the striatal projection neurons of the basal ganglia and interneurons in the olfactory bulb, both of which are severely reduced in mouse Gsx2 mutants. Accordingly, human patient studies identified 2 pathological GSX2 variant alleles in children with serious neurological symptoms, including dystonia and intellectual disabilities. Consistent with these symptoms, MRI imaging revealed severe basal ganglia agenesis. One GSX2 variant results in a null allele, however, the other is a missense variant (Q251R) that alters a key amino acid in the DNA binding HD. We generated a mouse model of this human variant and our initial studies suggest that the Q>R variant leads to a strong embryonic LGE and basal ganglia phenotype that is morphologically similar to embryos with Gsx2 null alleles. Furthermore, our preliminary data indicate that this human HD variant alters Gsx2 DNA binding specificity, and thereby may account for the observed phenotypes. Moreover, we recently determined that Gsx2 binds and regulates target genes via two mechanisms; as a monomer Gsx2 represses gene expression whereas on a subset of DNA sites cooperative Gsx2 binding to dimer sites appears to facilitate gene expression. Intriguingly, the Dlx HD TFs, which lie downstream of Gsx2 during LGE progenitor maturation, also bind monomer sites but instead of repressing they activate gene expression. In this application, we propose to determine how Gsx2 and the Dlx TFs regulate LGE gene expression during basal ganglia development. To achieve this goal, we will test the following hypotheses in 3 independent specific aims: 1) To test the hypothesis that Gsx2 controls basal ganglia development by mediating distinct gene regulatory outcomes in a DNA binding site dependent manner. 2) To test the hypotheses that Gsx2 and Dlx TFs regulate a common set of LGE genes though direct competition for shared enhancer elements. 3) To test the hypothesis that the GSX2Q251R human variant causes altered DNA binding specificity, and thereby results in the mis-regulation of LGE gene expression and ultimately basal ganglia agenesis. Our approach will combine the use of mouse genetics and human forebrain neural stem cell cultures with molecular, biochemical, and genomic approaches to study transcriptional control of neuronal specification in the developing basal ganglia. The unique expertise of our research team at CCHMC allows us to take this broad approach, and thus increases our chances to gain a deeper understanding of how Gsx factors control basal ganglia development as well as to uncover new gene regulatory mechanisms that underlie dysfunction in certain childhood neurological disorders.

正常的大脑功能取决于发育过程中神经回路的正确组装。这个过程以沿背腹侧和前后轴的神经祖细胞的图案化，从而产生不同的亚型神经元。许多关键转录因子（TFS）控制神经元亚型规范的过程。工作鼠标表明，同源域（HD）TF GSX2在模式和分化中扮演着重要的作用由胚胎小鼠外侧神经节隆起（LGE）中的祖细胞产生的神经元细胞类型脑脑。这些祖细胞引起细胞类型，包括基底神经节的纹状体投影神经元和嗅球中的中间神经元，它们在小鼠GSX2突变体中都大大降低。因此，人类患者研究确定了患有严重神经系统症状的儿童的2个病理GSX2变体等位基因，包括肌张力障碍和智力残疾。与这些症状一致，MRI成像显示严重的基底神经节发育不全。一个GSX2变体导致无效等位基因，但是，另一个是一个错义变体（Q251R），它改变了键 DNA结合HD中的氨基酸。我们生成了这种人类变体的鼠标模型，我们的初步研究表明 Q> r变体导致强烈的胚胎LGE和基底神经节表型在形态上与带有GSX2无效等位基因的胚胎。此外，我们的初步数据表明该人类高清变体改变了GSX2 DNA 结合特异性，因此可以解释观察到的表型。此外，我们最近确定了GSX2 通过两种机制结合和调节靶基因。作为单体GSX2抑制基因表达，而在子集上 DNA位点合作GSX2与二聚体位点结合似乎有助于基因表达。有趣的是，DLX HD LGE祖细胞成熟期间GSX2下游的TFS也结合了单体位点，而不是压抑它们激活基因表达。在此应用中，我们建议确定GSX2和DLX TFS如何调节LGE 基因神经节发育过程中的基因表达。为了实现这一目标，我们将在3中检验以下假设独立特定目的：1）检验以下假设：GSX2通过介导不同的不同基因调节结果以DNA结合位点依赖性方式。 2）测试GSX2和DLX TFS的假设通过直接竞争共享增强子元件的直接竞争，调节了一组通用的LGE基因。 3）检验假设 GSX2Q251R人类变体会导致DNA结合特异性改变，从而导致错误调节 LGE基因表达和最终基础神经节发育不全。我们的方法将结合鼠标的使用和人类前脑神经干细胞培养具有分子，生化和基因组方法的研究转录控制发展基底神经节中神经元规范。我们在CCHMC研究团队的独特专业知识允许我们采用这种广泛的方法，从而增加了我们对GSX因素如何更深入了解的机会控制基底神经节的发展以及发现基于功能障碍的新基因调节机制某些童年的神经系统疾病。