The role of TCF21 in coronary heart disease

TCF21在冠心病中的作用

• 批准号: 9122122
• 负责人: Robert Wirka
• 金额: $ 6.68万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9122122
• 关键词: Affect; Apolipoprotein E; Architecture; Arterial Fatty Streak; Atherosclerosis; BHLH Protein; Blood Pressure; Blood Vessels; Caucasians; Cell Count; Cell Differentiation process; Cells; Cessation of life; ChIP-seq; Characteristics; Chinese People; Coronary; Coronary artery; Coronary heart disease; Development; Diabetes Mellitus; Disease; Disease Progression; Embryo; Endothelium; Exhibits; Gene Expression; Genes; Genetic; Genetic Polymorphism; Genetic Variation; Genomics; Heart; Histology; Human; Immunohistochemistry; In Vitro; Knock-out; Label; Laboratories; Lead; Lesion; Light; Link; Location; Mediating; Molecular; Molecular Profiling; Mus; Myocardial Infarction; Pathway interactions; Phenotype; Plant Roots; Play; Population; Reporter; Reporter Genes; Risk; Risk Factors; Role; Rupture; Series; Shapes; Smoking; Smooth Muscle Myocytes; Staging; Stem cells; Structure; Time; Transgenic Organisms; Tunica Adventitia; United States; Vascular Smooth Muscle; blood lipid; cell type; cost; genetic variant; genome wide association study; genome-wide; heart disease risk; in vivo; knock-down; laser capture microdissection; migration; molecular phenotype; mouse model; novel; novel therapeutic intervention; programs; public health relevance; research study; response; therapeutic target; transcriptome sequencing; treatment strategy

 DESCRIPTION (provided by applicant): Although approximately 40% of the risk for coronary heart disease (CHD) can be attributed to genetic variation, we currently understand only a fraction of genetic variants that contribute to this risk. Recent genome wide association studies (GWAS) have pointed to CHD-associated loci that could be contributing to CHD pathobiology via completely unexpected mechanisms, raising the possibility of new therapeutic strategies. Our group has recently shown that one of these CHD-associated polymorphisms directly affects expression of the TCF21 gene, implicating it in CHD pathobiology. TCF21 is a basic helix-loop-helix transcription factor that is found in the developing coronary vasculature, where it plays a critical role in determining cell fate decisions in precursor smooth muscle cells (SMCs). Tcf21-expressing cells are present in the adventitia of human and murine coronary arteries and the aortic media. In response to atherosclerotic disease in the ApoE-/- mouse model, these Tcf21-expressing cells migrate into the developing lesion and align at the fibrous cap, where they show evidence of SMC differentiation. This is especially intriguing given that SMCs are thought to strengthen the fibrous cap structure, which protects against plaque rupture and myocardial infarction. However, the role of Tcf21 in these precursor SMCs is unknown. The series of experiments described herein aim to determine how Tcf21 modulates the phenotype of precursor SMCs and lesion composition in vivo, and to elucidate the molecular pathways by which these effects are mediated. Together, these studies will significantly expand our understanding of the role of SMCs in CHD pathobiology. In Aim 1, we will use conditional Tcf21 knockout and TCF21 transgenic over-expressing Apo E-/- mice to determine how changes in Tcf21 expression affect precursor SMC recruitment and phenotype within the atherosclerotic plaque, and how these changes affect plaque architecture. We will use classical histology and immunohistochemistry to examine plaque composition and structure, with a special focus on the protective fibrous cap. We will track Tcf21-expressing cells via an inducible fluorescent reporter gene. In Aim 2, we will use cells isolated from Tcf21 reporter mice to characterize the in vivo molecular phenotype of Tcf21 lineage-traced cells. A Tcf21-specific fluorescent reporter gene will permanently label Tcf21-expressing cells and allow their identification at various time points during disease progression. These Tcf21 lineage-traced cells will be isolated from aortic root lesions using laser capture microdissection and will undergo RNA sequencing, which will produce a readout of cellular gene expression at progressive stages during plaque development. This will allow molecular phenotyping of these cells and will shed light on important pathways that shape the developing vulnerable atherosclerotic plaque.

 描述(申请人提供)：虽然大约40%的冠心病风险可以归因于基因变异，但我们目前只了解到导致这种风险的基因变异的一小部分。最近的全基因组关联研究指出，CHD相关基因可能通过完全意想不到的机制对CHD病理生物学起作用，这增加了新治疗策略的可能性。我们的团队最近发现，这些与CHD相关的基因之一直接影响TCF21基因的表达，这可能与CHD的病理生物学有关。TCF21是一种基本的螺旋-环-螺旋转录因子，在发育中的冠状动脉血管系统中发现，在决定前体平滑肌细胞(SMCs)细胞命运的过程中发挥着关键作用。表达TCF21的细胞存在于人和小鼠冠状动脉外膜和主动脉中膜。在ApoE-/-小鼠模型中，为了应对动脉粥样硬化性疾病，这些表达TCF21的细胞迁移到发育中的病变中，并排列在纤维帽，在那里它们显示出SMC分化的证据。这一点特别耐人寻味，因为SMC被认为可以加强纤维帽结构，防止斑块破裂和心肌梗死。然而，TCF21在这些前体SMC中的作用尚不清楚。本文描述的一系列实验旨在确定TCF21如何调节体内前体SMC的表型和病变成分，并阐明这些影响的分子途径。总之，这些研究将极大地扩大我们对SMCs在冠心病病理生物学中的作用的理解。在目标1中，我们将使用条件性TCF21基因敲除和TCF21转基因过表达Apo E-/-小鼠来确定TCF21表达的变化如何影响动脉粥样硬化斑块中前体SMC的募集和表型，以及这些变化如何影响斑块结构。我们将使用经典的组织学和免疫组织化学来检查斑块的成分和结构，特别是保护纤维帽。我们将通过一个可诱导的荧光报告基因来跟踪TCF21表达的细胞。在目标2中，我们将使用从TCF21报告鼠分离的细胞来表征TCF21谱系追踪细胞的体内分子表型。TCF21特异的荧光报告基因将永久标记TCF21表达的细胞，并允许在不同的时间点识别它们 在疾病发展的过程中。这些TCF21谱系追踪细胞将使用激光捕获显微解剖从主动脉根部病变中分离出来，并将进行RNA测序，这将产生斑块发展过程中进行性阶段的细胞基因表达读数。这将允许这些细胞的分子表型，并将阐明形成发展中的脆弱动脉粥样硬化斑块的重要途径。