Identifying tobacco-genetic interactions through study of the aryl hydrocarbon receptor pathway.

通过研究芳基碳氢化合物受体途径来识别烟草与遗传的相互作用。

• 批准号: 10591597
• 负责人: THOMAS QUERTERMOUS
• 金额: $ 66.76万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10591597
• 关键词: ARNT gene; ATAC-seq; Address; Affect; Alkaline Phosphatase; Anatomy; Animal Model; Aorta; Apolipoprotein E; Arterial Fatty Streak; Aryl Hydrocarbon Receptor; Atherosclerosis; Binding; Biological Assay; Biological Models; Cardiovascular Diseases; Cardiovascular system; Cell Lineage; Cell model; Cells; Cessation of life; Chondrocytes; Coronary Arteriosclerosis; Coronary artery; Data; Dioxins; Disease; Disease Progression; Disease model; Environmental Exposure; Environmental Risk Factor; Epigenetic Process; Exposure to; Functional disorder; Genes; Genetic; Genetic Transcription; Goals; Heterodimerization; Histology; Human; Human Genetics; Human Genome; Hydrocarbons; In Vitro; Individual; Knock-out; Knockout Mice; Lesion; Ligands; Link; Mediating; Modeling; Molecular; Morbidity - disease rate; Mus; Pathway interactions; Phenotype; Physiological; Population; Receptor Signaling; Research; Risk; Role; Smooth Muscle Myocytes; Tissues; Tobacco; Tobacco smoke; Toxic Environmental Substances; Toxin; United States; Vascular Diseases; Vascular calcification; Wild Type Mouse; Xenobiotics; aryl hydrocarbon receptor ligand; conditional knockout; disorder risk; epigenomics; exposed human population; gene environment interaction; genetic approach; genetic association; in vitro Model; in vivo; innovation; insight; loss of function; mortality; mouse model; novel; novel strategies; preventable death; promoter; protective effect; public health relevance; response; reverse genetics; single-cell RNA sequencing; transcription factor; transcriptomics

Human exposure to environmental toxins such as those in tobacco related products are the leading cause of preventable deaths in the United States, with the greatest effect on morbidity and mortality through promotion of coronary artery disease (CAD). However, the molecular mechanisms by which environmental exposures increase CAD risk are not well understood. Furthermore, genes that might participate in gene by environment interactions have been difficult to identify at the population level. Thus, our longterm goal is to use a reverse genetics approach to study the interaction of xenobiotic toxins with relevant known CAD-associated genes. One such gene is the aryl-hydrocarbon receptor (AHR). Well-known ligands of AHR are dioxins and poly-aryl hydrocarbons, which are major components of tobacco smoke and known promoters of atherosclerosis in animal models. Genes encoding AHR, its heterodimerization partner ARNT, and other factors in this pathway are all linked to CAD risk through human genetic association studies. Single cell RNA sequencing (scRNAseq) studies of smooth muscle cell (SMC)-specific Ahr knockout (KO) atherosclerotic mice showed a significant increase in the proportion of phenotypic transition SMC that express chondrocyte markers, identifying cells we term “chondromyocytes” (CMC). These findings were correlated with larger lesion size, increased lineage- traced SMC contribution to the plaque, decreased lineage-traced SMC in the fibrous cap, and increased lesion alkaline phosphatase activity in the Ahr KO mice. These findings reveal that Ahr expression in SMC inhibits their transition to CMC and ameliorates vascular disease pathophysiology. These data are in contrast with a number of studies showing that Ahr activation by xenobiotic ligands such as dioxin promote atherosclerosis, and suggest a unique hypothesis. We postulate that Ahr normally has a beneficial effect on SMC in the disease setting, inhibiting a harmful cell state transition to the CMC phenotype and disease progression, and that this protective effect is blocked by xenobiotic toxin activation. We thus propose to examine this hypothesis through the following Aims. In Aim 1, we will investigate how Ahr responds to xenobiotic ligand activation in the disease setting, with respect to SMC phenotype and cellular lesion anatomy. These studies will employ the Ahr SMC-specific conditional KO and SMC lineage traced ApoE KO atherosclerosis model. Aim 2 will focus on the transcriptomic and epigenomic effects of xenobiotic ligand in vivo activation with the same mouse disease model, with combined scRNAseq and single cell ATAC sequencing (scATACseq). Finally, in Aim 3 we propose to employ human coronary artery SMC as an in vitro model system to validate, and characterize the downstream pathways for, TFs identified in the previous Aim that interact with AHR to regulate the phenotypic transition of SMC to chondromyocytes. These studies investigate a highly innovative hypothesis, and will provide significant insights into cellular and molecular mechanisms by which tobacco and other environmental risk factors promote CAD risk.

人类接触环境毒素（例如与烟草相关产品的毒素）是主要原因 美国可预防的死亡，通过促进对发病率和死亡的影响最大 冠状动脉疾病（CAD）。但是，环境暴露的分子机制 增加CAD风险尚不清楚。此外，可能通过环境参与基因的基因 在人群一级很难识别互动。那就是我们的长期目标是使用反向 研究异种生物毒素与相关已知CAD相关基因的相互作用的遗传学方法。 一种这样的基因是芳基氢化碳受体（AHR）。众所周知的AHR配体是二恶英和poly-arryl 碳氢化合物是烟草烟雾的主要成分，也是已知的动脉粥样硬化促进剂 动物模型。编码AHR的基因，其异二聚体伴侣ARNT以及该途径中的其他因素 通过人类遗传关联研究与CAD风险有关。单细胞RNA测序（SCRNASEQ） 平滑肌细胞（SMC）特异性AHR敲除（KO）动脉粥样硬化小鼠的研究表明 增加表达软骨细胞标记的表型过渡SMC的比例增加，鉴定细胞 术语“软骨细胞”（CMC）。这些发现与较大的病变大小相关，谱系增加 - 追踪SMC对牙菌斑的贡献，纤维帽中谱系跟踪的SMC减少，并增加病变 AHR KO小鼠中的碱性磷酸酶活性。这些发现表明，SMC中的AHR表达抑制 它们向CMC的过渡并改善了血管疾病的病理生理学。这些数据与 研究数量表明，异种生物配体（例如二恶英）的AHR激活促进动脉粥样硬化， 并提出一个独特的假设。我们假设AHR通常对SMC具有有益的作用 疾病设置，抑制有害细胞状态向CMC表型和疾病的过渡 进展，这种保护作用被异种毒素激活阻止。因此，我们建议 通过以下目的检查这一假设。在AIM 1中，我们将调查AHR如何回应 关于SMC表型和细胞病变解剖结构，在疾病环境中的异种配体激活。 这些研究将采用AHR SMC特异性的有条件KO和SMC谱系追踪的APOE KO 动脉粥样硬化模型。 AIM 2将重点关注异种生物配体在 与同一小鼠疾病模型的体内激活，与scrnaseq和单细胞合并 测序（scatacseq）。最后，在AIM 3中，我们建议将人类冠状动脉SMC作为体外 验证和表征下游途径的模型系统，在上一个目标中确定的TFS 与AHR相互作用以调节SMC向软骨细胞的表型过渡。这些研究 研究高度创新的假设，并将为细胞和分子提供重要的见解 烟草和其他环境风险因素促进CAD风险的机制。