Zfp462遗传缺陷小鼠模型构建及其导致上睑下垂的机制研究

Ptosis is described as unilateral or bilateral involuntary abnormal drooping of the upper eyelids, with secondary narrowing of the vertical palpebral fissure, which is a common eye disease. It can occur in an isolation form or as a symptom of a disease or syndrome, leading to vision disorders such as amblyopia and vision loss, as well as significant cosmetic-related psychological and social disorders. Genetic and environmental factors are proposed to be associated with the disease development. Though two loci associated with hereditary congenital ptosis have been identified, most families with the disorder remain unknown. In our preliminary study, a de novo disease-causing ZNF462 mutation was identified in a pedigree with hereditary congenital ptosis, and the constructed znf462 knock-down zebrafish partially mimicked the disease phenotypes. In this study, more cases with congenital ptosis will be recruited. The association between the ZNF462 gene and ptosis will be further confirmed, and the gene mutation frequencies will be analyzed. New pathogenic genes will be identified by combination of exome sequencing and whole genome sequencing. The effect of the mutation will be evaluated by constructing plasmids with mutated gene. By construction of knock-in mouse model with mutant Zfp462, an ortholog of human ZNF462 gene, human disease will be mimicked to a greater extent. Study on the regulatory network in which mutated gene participated, will further reveal the pathogenic mechanism of the ZNF462 gene mutation responsible for ptosis.

上睑下垂为单侧或双侧上睑异常不自主下垂并继发垂直性睑裂缩窄，是一种常见眼病。既可单独出现，也可作为疾病或综合征体征之一，可引起弱视和视觉丧失等视觉障碍，造成外观美容相关的心理和社会障碍。目前认为其发生与遗传和环境因素相关，已鉴定两个遗传性先天性上睑下垂疾病基因位点，大部分家系致病原因不明。我们前期在一个先天性遗传性上睑下垂家系中发现ZNF462基因新生致病突变，并通过构建znf462基因敲减斑马鱼模型部分模拟疾病表型。本研究拟进一步收集先天性上睑下垂病例，验证ZNF462基因与上睑下垂关系，分析ZNF462基因突变频率；外显子组测序和全基因组测序相结合鉴定新的上睑下垂基因；构建突变质粒评估突变效应；通过构建人ZNF462的小鼠同源基因Zfp462突变敲入小鼠模型，更大程度模拟人类疾病。研究突变基因参与调控网络，解析ZNF462基因突变导致上睑下垂发生的机制。

上睑下垂为单侧或双侧上睑异常不自主下垂并继发垂直性睑裂缩窄，是一种常见眼病。既可单独出现，也可作为疾病或综合征体征之一，可引起弱视和视觉丧失等视觉障碍，造成外观美容相关的心理和社会障碍。目前认为其发生与遗传和环境因素相关，已鉴定两个遗传性先天性上睑下垂疾病基因位点，大部分家系致病原因不明。我们前期在一个先天性遗传性上睑下垂家系中发现ZNF462基因新生致病突变，并通过构建znf462基因敲减斑马鱼模型部分模拟疾病表型。本研究进一步收集了先天性上睑下垂病例，应用外显子组测序等技术鉴定了6个家系的致病基因和突变；构建了突变质粒转染细胞进行体外培养在细胞水平评估了ZNF462基因突变效应；通过构建人ZNF462的小鼠同源基因Zfp462遗传缺陷小鼠模型解析了ZNF462基因突变导致上睑下垂发生的可能机制。