Regulation of Craniofacial Development by ALX Transcription Factors

ALX转录因子对颅面发育的调节

基本信息

批准号：
10461139
负责人：
RULANG JIANG
金额：
$ 65.66万
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：
2020
资助国家：
美国
起止时间：
2020-09-09 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10461139
关键词：
Animal Model Anterior Apoptosis Bioinformatics Biological Models Biology Cardiac Caring Cartilage Cell Differentiation process Cell physiology Cells Cephalic Cleft Palate Clinical Clustered Regularly Interspaced Short Palindromic Repeats Congenital Abnormality Connective Tissue Data Development Developmental Biology Ectoderm Embryo Etiology Exhibits Face Family First Pharyngeal Arch Frontal bone structure Frontonasal Prominence Frontonasal dysplasia Ganglia Gene Expression Gene Family Genes Genetic Genetic Counseling Genome Impairment Jaw Lateral Lead Life Maxilla Medial Mediating Microphthalmos Molecular Molecular Diagnosis Morphogenesis Multipotent Stem Cells Mus Mutant Strains Mice Mutation Neural Crest Neural Crest Cell Neuroglia Neuronal Differentiation Neurons Nose Operative Surgical Procedures Oral cavity Orbital separation excessive Pathogenicity Patients Pattern Phenotype Pigments Process Regulation Research Research Project Grants Role Syndrome TWIST1 gene Tissues bone cell fate specification craniofacial craniofacial bone craniofacial development craniofacial disorder craniofacial structure cranium face bone structure gene regulatory network genome editing homeodomain improved innovation loss of function mutation malformation migration mouse model mutant novel single-cell RNA sequencing skeletal tissue stem cells transcription factor transcriptome vertebrate embryos

项目摘要

Abstract Frontonasal dysplasia (FND), also known as median cleft face syndrome, is a major class of craniofacial birth defects that profoundly impact the form and function of the face. FND patients require multiple corrective surgeries and often suffer life-long impairment. Whilst most FND cases occur sporadically with unknown etiology, loss-of-function mutations in each of the three ALX family genes, ALX1, ALX3, and ALX4, have been identified as the genetic causes for autosomal recessive FND, with disruption of ALX1 associated with severe facial clefting and extreme microphthalmia in FND3 patients while mutations in ALX3 and ALX4 resulted in milder but clinically distinctive frontonasal malformations. Little is known about how ALX transcription factors regulate craniofacial development, and the overall molecular mechanism controlling frontonasal development is poorly understood. In preliminary studies, we have generated Alx1 mutant mice using CRISPR-mediated genome editing and found that they recapitulated the FND3 phenotypes, including reduced frontonasal bones and cartilages, cleft palate, and microphthalmia. We found that Alx1-/- embryos exhibited ectopic neuroglial differentiation and reduction in ectomesenchymal gene expression in the frontonasal prominence. Moreover, Alx1-/-Alx4-/- double mutant mouse embryos exhibited increased ectopic cranial ganglia and much severer frontonasal deficiency than Alx1-/- mutants. Previous studies in multiple animal model systems revealed that the Twist1 transcription factor, whose expression is activated in cranial neural crest cells at the onset of migration, is critical for ectomesenchyme specification. Remarkably, while the molecular mechanism acting downstream of Twist1 in promoting ectomesenchymal fate is still unclear, Twist1-/- mouse embryos failed to activate the expression of all three Alx genes in cranial neural crest cells. Our finding of ectopic neuroglial differentiation in the frontonasal regions of Alx1-/- and Alx1-/-Alx4-/- embryos suggests that Twist1 and the ALX transcription factors act in the same molecular network to regulate cranial neural crest fate determination between the ectomesenchymal and neuroglial lineages. The specific aims of this research project are to determine the cellular and molecular mechanisms mediating ALX transcription factor function in frontonasal development and to unravel and reconstruct the gene regulatory network consisting of Twist1 and ALX transcription factors regulating cranial neural crest differentiation. Results from these studies will fill a longstanding critical gap in craniofacial developmental biology and lead to new improvements in molecular diagnosis and treatment/care of a large number of craniofacial disorders.

抽象的额增发育不良（FND），也称为中值裂综合症，是一类主要的颅面。出生缺陷会对面部的形式和功能产生深远的影响。 FND患者需要多个纠正措施手术并经常遭受终身障碍。虽然大多数FND案件偶尔发生，但未知病因，三个ALX家族基因的功能丧失突变，ALX1，ALX3和ALX4已是被确定为常染色体隐性fnd的遗传原因，与严重相关的Alx1中断 FND3患者的面部裂口和极端的微观恐惧症，而ALX3和ALX4中的突变导致温和但临床上独特的额骨畸形。关于阿尔克斯转录因子的知识知之甚少调节颅面发育以及控制额骨发育的总体分子机制理解很差。在初步研究中，我们已经使用CRISPR介导的ALX1突变小鼠了基因组编辑并发现它们概括了FND3表型，包括减少额骨的骨骼和软骨，left裂和微观心脏。我们发现alx1 - / - 胚胎表现出异位神经乳头额骨突出中的外观基因表达的分化和降低。而且， ALX1 - / - ALX4 - / - 双突变小鼠胚胎表现出增加的异位颅神经节，并且更加较好额骨缺乏比Alx1 - / - 突变体。多个动物模型系统的先前研究表明 Twist1转录因子，其表达在开始时在颅神经rest细胞中激活迁移，对于过骨质规范至关重要。值得注意的是，而分子机制作用在促进外质命运中扭曲1的下游仍不清楚，扭曲1 - / - 小鼠胚胎未能激活颅神经rest细胞中所有三个ALX基因的表达。我们发现异位神经元的发现 Alx1 - / - 和Alx1 - / - Alx4 - / - 胚胎的额骨区域的分化表明Twist1和Alx 转录因子在同一分子网络中作用以调节颅神经冠命运的确定在典型和神经层谱系之间。该研究项目的具体目的是确定介导ALX转录因子功能功能的细胞和分子机制开发，解开和重建由Twist1和Alx组成的基因调节网络调节颅神经分化的转录因子。这些研究的结果将填补长期存在颅面发育生物学的临界差距，并导致分子的新改善大量颅面疾病的诊断和治疗/护理。