Functional genomics investigation of pleiotropic vascular disease loci

项目总结 复杂的血管疾病，如冠状动脉疾病(CAD)、心肌梗死(MI)和冠状动脉 动脉钙化(CAC)在全球范围内造成相当大的公共健康负担，涉及遗传性和 终生的环境风险因素。鉴于血管疾病在人类中的发病率不断上升 人口，迫切需要新的治疗和预防措施，以初级 血管壁上的疾病过程。全基因组关联研究(GWAS)已经确定了数百个 与血管疾病风险相关的遗传基因座。大规模的功能基因组研究已经开始 解决了这些基因座上的许多致病基因、变异和途径，并展示了共同的遗传 病因学。然而，将这些基因发现转化为生物学和生物化学仍然是一个挑战。 与临床相关的见解。超过一半的CAD/MI基因座与经典风险无关 因素，并可能指向血管功能障碍。我们小组和其他人采用了一种基于系统的方法 冠状动脉平滑肌疾病危险基因改变的基因和机制研究进展 细胞(SMC)。SMC通常调节血管张力，但在动脉粥样硬化中起关键作用，因为它的收缩作用 基因程序在表型转换为免疫细胞、成纤维细胞样细胞和成骨细胞样细胞的过程中被劫持。 应用多组学和数量性状基因座定位技术对人冠状动脉SMC及组织的研究 确定了与CAD相关的血管功能障碍的候选致病基因和机制。单细胞分析 冠心病相关转录因子(如TCF21)在人类冠状动脉病变中的关键作用 在动脉粥样硬化中调节SMC表型转换。应用单细胞表观基因组图谱分析冠状动脉 动脉(n=41)，我们还发现了新的SMC特异性转录调节因子，与多个 血管疾病。综合精细映射分析将四个半LIM域5(FHL5)作为 冠心病/心肌梗塞和亚临床血管疾病的致病基因。有趣的是，FHL5过表达减少 SMC的收缩，以及增殖和钙化的增加，与CAC的遗传关联一致。 最后，SMC中的FHL5染色质和转录组图谱支持其作为转录辅助因子的作用，通过 改变SMC的收缩能力和细胞外基质的表达/调节。这些数据表明，阐明其 跨调控途径可能解决这些情况下多效性风险的机制。在此，我们计划 在体外进行人血管细胞和动脉中FHL5的功能基因组研究，以确定 它通过改变肌动蛋白细胞骨架和细胞外基质调节在血管功能障碍中的作用，以及 血管反应性。我们将进一步揭示其靶向结合区域、蛋白质相互作用，并构建多组体 确定FHL5调节组对亚临床和晚期疾病影响的基因调控网络 结果。这些研究将共同揭示多种血管的关键调控级联反应和生物标记物 为消除这些使人衰弱的疾病提供新的早期治疗或预防战略。

PROJECT SUMMARY Complex vascular diseases such as coronary artery disease (CAD), myocardial infarction (MI), and coronary artery calcification (CAC) pose considerable public health burden worldwide and involve both genetic and environmental risk factors over a lifetime. Given the rising prevalence of vascular diseases across human populations, there is an urgent need for new treatments and preventative measures that target the primary disease processes in the vessel wall. Genome-wide association studies (GWAS) have identified hundreds of genetic loci associated with vascular disease risk. Large-scale functional genomic studies have begun to resolve many of the causal genes, variants, and pathways at these loci and demonstrated shared genetic etiologies. However, it still remains a challenge to translate these genetic discoveries into biologically and clinically relevant insights. More than half of the CAD/MI loci are associated independently of classical risk factors and may point to vascular dysfunction. Our group and others have adopted a systems-based approach to prioritize the genes and mechanisms altered by disease risk loci in human coronary artery smooth muscle cells (SMC). SMC normally regulate vascular tone but play critical roles in atherosclerosis as their contractile gene program is hijacked during phenotypic switching to immune cell, fibroblast-like, and osteoblast-like cells. Using multi-omics and quantitative trait locus mapping in human coronary artery SMC and tissues we recently identified candidate causal genes and mechanisms for CAD-related vascular dysfunction. Single-cell analyses of human coronary lesions demonstrated a critical role for CAD-associated transcription factors (e.g. TCF21) in regulating SMC phenotypic switching during atherosclerosis. Using single-cell epigenomic profiling of coronary arteries (n=41) we also identified novel SMC specific transcriptional regulators that are associated with multiple vascular diseases. Integrative fine-mapping analyses prioritized Four-and-a-Half LIM domains 5 (FHL5) as a causal gene for CAD/MI and subclinical vascular diseases. Interestingly, FHL5 overexpression decreased SMC contractility, and increased proliferation and calcification, consistent with the genetic association for CAC. Finally, FHL5 chromatin and transcriptome profiling in SMC support its role as a transcriptional cofactor, by altering SMC contractility and extracellular matrix expression/regulation. These data suggest that elucidating its trans-regulatory pathways may resolve mechanisms of pleiotropic risk across these conditions. Herein, we plan to perform functional genomic studies of FHL5 in both human vascular cells and arteries ex vivo to determine its role in vascular dysfunction, through altered actin cytoskeleton and extracellular matrix regulation, and vasoreactivity. We will further reveal its target binding regions, protein interactomes, and construct multi-omic gene regulatory networks to determine the effects of the FHL5 regulome on subclinical and advanced disease outcomes. Together these studies will reveal key regulatory cascades and biomarkers for multiple vascular conditions and inform novel early treatment or prevention strategies to eradicate these debilitating diseases.