Epigenetic regulation of lens fiber cell differentiation: The role of DNA methyla

晶状体纤维细胞分化的表观遗传调控：DNA甲基化的作用

• 批准号: 8229812
• 负责人: MICHAEL L ROBINSON
• 金额: $ 21.3万
• 依托单位: MIAMI UNIVERSITY OXFORD
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8229812
• 关键词: Address; Candidate Disease Gene; Cell Cycle; Cell Differentiation process; Cell division; Cells; CpG dinucleotide; Crystallins; Cytosine; DNA; DNA Maintenance; DNA Methylation; DNA Methyltransferase; DNA Modification Methylases; DNA Modification Process; Development; E-Cadherin; Enzymes; Epigenetic Process; Epithelial; Epithelial Cells; Epithelium; Equilibrium; Filament; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Generations; Genes; Genetic; Guanosine; Histones; Knock-out; Knowledge; Lens Fiber; Maintenance; Mammalian Cell; Mammals; Medicine; Methylation; Methyltransferase; Modification; Molecular Profiling; Mus; Mutation; Organism; Partner in relationship; Patients; Phenotype; Play; Pluripotent Stem Cells; Proteins; RNA; RNA Sequences; Regulation; Relative (related person); Reporting; Repression; Role; Stem cells; Tissue-Specific Gene Expression; Vertebrates; Zebrafish; cell type; demethylation; ds-DNA; fiber cell; filensin; gene repression; lens; mutant; next generation; preference; prevent; promoter; research study; transcription factor

DESCRIPTION (provided by applicant): Lens fiber cell differentiation involves a coordinated change in gene expression. A number of genes including Pax6, FoxE3 and E-cadherin are expressed in lens epithelial cells but down-regulated in lens fiber cells. Conversely many other genes including Aquaporin0, 2- and 3-crystallins and lens-specific beaded filament proteins CP49 and filensin are not expressed in lens epithelial cells but are turned on in lens fiber cells. In recent years it has become increasingly clear that epigenetic modification (reversible covalent modification of DNA or histone proteins) of chromosomal DNA plays a major role in gene regulation. Among the best studied epigenetic modifications is methylation of cytosine in CpG dinucleotides in DNA. Methylation of DNA in mammalian cells is accomplished by Dnmt1, which is responsible for maintaining epigenetic methylation through cell divisions, and Dnmt3a and Dnmt3b, which are responsible for creating de novo methylation changes during development. Promoter DNA methylation is associated with transcriptional repression of genes. Despite the wealth of knowledge of transcription factors involved in lens development, very little is known about the epigenetic regulation of lens fiber cell differentiation. Recent evidence suggests that Dnmt1 and Dnmt3 activity are specifically required for lens development in zebrafish. We hypothesize that the balance between promoter methylation and demethylation is required for proper lens fiber cell differentiation, and that this balance will require the activity of both maintenance and de novo methylation activity. We propose that maintenance methylation will be required to prevent the expression of genes associated with fiber cell differentiation in the lens epithelium and that de novo methylation will be required to repress the expression of lens epithelial genes during fiber cell differentiation. We will investigate the role of DNA methylation in fiber cell differentiation using both conditional genetic strategies in mice lacking maintenance or de novo methylases in the lens lineage. We will use histological, immunological and high throughput next generation sequencing strategies to comprehensively investigate how DNA methylation influences lens fiber cell differentiation. PUBLIC HEALTH RELEVANCE: Recent experiments demonstrating that epigenetic reprogramming can convert differentiated cell types into pluripotent stem cells makes clear the critical importance for understanding the epigenetic regulation of the differentiated phenotype. We propose that the lens represents a unique opportunity to understand how epigenetic DNA methylation regulates differentiation. This understanding will be important not only for lens development, but for a global understanding of how to manipulate differentiated states, which is critical for the generation of patient-specific stem cells in medicine.

描述（由申请人提供）：透镜纤维细胞分化涉及基因表达的协调变化。包括Pax 6、FoxE 3和E-cadherin在内的许多基因在透镜上皮细胞中表达，但在透镜纤维细胞中下调。相反，包括水通道蛋白0、2-和3-晶体蛋白和晶状体特异性珠状丝蛋白CP 49和filensin的许多其它基因在透镜上皮细胞中不表达，但在透镜纤维细胞中被开启。近年来，越来越清楚的是，染色体DNA的表观遗传修饰（DNA或组蛋白的可逆共价修饰）在基因调控中起着重要作用。其中研究最多的表观遗传修饰是DNA中CpG二核苷酸中胞嘧啶的甲基化。哺乳动物细胞中DNA的甲基化由Dnmt 1和Dnmt 3a和Dnmt 3b完成，Dnmt 1负责通过细胞分裂维持表观遗传甲基化，Dnmt 3a和Dnmt 3b负责在发育过程中产生从头甲基化变化。启动子DNA甲基化与基因的转录抑制有关。尽管对参与透镜发育的转录因子有丰富的了解，但对透镜纤维细胞分化的表观遗传调控知之甚少。最近的证据表明，Dnmt 1和Dnmt 3的活动是专门需要的透镜发展在斑马鱼。我们假设启动子甲基化和去甲基化之间的平衡是透镜纤维细胞分化所必需的，并且这种平衡将需要维持和从头甲基化活性两者的活性。我们提出，维持甲基化将需要防止与纤维细胞分化相关的基因在透镜上皮细胞的表达和从头甲基化将需要在纤维细胞分化过程中抑制透镜上皮细胞基因的表达。我们将在缺乏维持或透镜谱系中从头甲基化酶的小鼠中使用两种条件遗传策略来研究DNA甲基化在纤维细胞分化中的作用。我们将使用组织学，免疫学和高通量下一代测序策略，全面研究DNA甲基化如何影响透镜纤维细胞分化。 公共卫生相关性：最近的实验表明，表观遗传重编程可以将分化的细胞类型转化为多能干细胞，这清楚地表明了理解分化表型的表观遗传调控的至关重要性。我们认为，透镜代表了一个独特的机会，了解表观遗传DNA甲基化如何调节分化。这种理解不仅对透镜的开发很重要，而且对如何操纵分化状态的全球理解也很重要，这对于医学中患者特异性干细胞的产生至关重要。