Datasheet3_Single-cell RNA sequencing and ATAC sequencing identify novel biomarkers for bicuspid aortic valve-associated thoracic aortic aneurysm.pdf

IntroductionBicuspid aortic valve (BAV) is the most prevalent congenital cardiovascular defect and known to cause thoracic aortic aneurysms (TAAs). To improve our understanding of BAV pathogenesis, we characterized the cellular composition of BAV tissues and identified molecular changes in each cell population.
MethodsTissue samples from two patients with BAV and two heart transplant donors were analyzed using single-cell RNA sequencing, assay for transposase-accessible chromatin using sequencing, and weighted gene coexpression network analysis for differential gene analysis. TAA-related changes were evaluated by comparing the proportion of each cell type and gene expression profiles between TAA and control tissues. Further, by combining our single-cell RNA sequencing data with publicly available data from genome-wide association studies, we determined critical genes for BAV.
ResultsWe found 20 cell subpopulations in TAA tissues, including multiple subtypes of smooth muscle cells, fibroblasts, macrophages, and T lymphocytes. This result suggested that these cells play multiple functional roles in BAV development. Several differentially expressed genes, including CD9, FHL1y, HSP90AA1, GAS6, PALLD, and ACTA2, were identified.
DiscussionWe believe that this comprehensive assessment of the cellular composition of TAA tissues and the insights into altered gene expression patterns can facilitate identification of novel diagnostic biomarkers and therapeutic targets for BAV-associated TAA.

引言
二叶主动脉瓣（bicuspid aortic valve, BAV）是最常见的先天性心血管畸形，且已被证实可引发胸主动脉瘤（thoracic aortic aneurysms, TAAs）。为加深对二叶主动脉瓣发病机制的理解，本研究对二叶主动脉瓣病变组织的细胞构成进行了表征，并鉴定了各细胞群体的分子变化。

方法
本研究对2例二叶主动脉瓣患者的组织样本与2例心脏移植供体的组织样本开展分析，所用技术包括单细胞RNA测序（single-cell RNA sequencing）、转座酶可及性染色质测序分析（assay for transposase-accessible chromatin using sequencing）以及用于差异基因分析的加权基因共表达网络分析（weighted gene coexpression network analysis）。通过对比胸主动脉瘤组织与对照组织的各细胞类型占比及基因表达谱，评估与胸主动脉瘤相关的分子变化。此外，本研究将本团队的单细胞RNA测序数据与公开的全基因组关联研究（genome-wide association studies）数据相结合，确定了与二叶主动脉瓣相关的关键基因。

结果
本研究在胸主动脉瘤组织中鉴定出20个细胞亚群，涵盖平滑肌细胞、成纤维细胞、巨噬细胞及T淋巴细胞的多种亚型。该结果提示，上述细胞在二叶主动脉瓣的发生发展过程中发挥了多重功能作用。研究团队同时鉴定出多个差异表达基因，包括CD9、FHL1y、HSP90AA1、GAS6、PALLD及ACTA2。

讨论
本研究认为，对胸主动脉瘤组织细胞构成的全面解析，以及对基因表达模式改变的深入洞察，将有助于筛选与二叶主动脉瓣相关胸主动脉瘤的新型诊断生物标志物与治疗靶点。