Key regulatory differentially expressed genes in atrial septal defect children treated with occlusion devices

Atrial septal defects (ASDs) is the most common types of cardiac septal defects in congenital heart defects. In addition to traditional therapy, interventional closure has become the main treatment methods. However, the molecular events and mechanisms underlying the repair progress by occlusion device remain unknown. In this study, we aimed to characterize differentially expressed genes (DEGs) in the blood of patients treated with occlusion devices (metal or poly-L-lactic acid devices) using RNA-sequencing, and further validated them by qRT-PCR analysis to finally determine the expression of key mediating genes after closure of ASD treatment. The result showed that total 1045 genes and 1523 genes were expressed differently with significance in metal and poly-L-lactic acid devices treatment, respectively. The 115 overlap genes from the different sub-analyses are illustrated. The similarities and differences in gene expression reflect that the body response process involved after interventional therapy for ASDs has both different parts that do not overlap and the same part that crosses. The same portion of body response regulatory genes are key regulatory genes expressed in the blood of patients with ASDs treated with closure devices. The gene ontology enrichment analysis showed that biological processes affected in metal devices therapy are immunity response with CXCR4 genes and poly-L-lactic acid devices treatment key pathway is nuclear-transcribed mRNA catabolic process and proteins targeting to endoplasmic reticulum process with ribosomal proteins (such as RPS26). We confirmed CXCR4, TOB1 and DDIT4 gene expression are both significantly down regulated toward the pre-therapy level after the post treatment in both therapy groups by qRT-PCR. Our study suggests the potential role of CXCR4, DDIT4 and TOB1 may be key regulatory genes in the process of endothelialization in the repair progress of ASDs, providing molecular insights in this progress for the future study.

房间隔缺损（Atrial septal defects, ASDs）是先天性心脏病中最为常见的心脏间隔缺损类型。除传统治疗方案外，介入封堵术已成为其主流治疗手段。然而，封堵器修复过程背后的分子事件与调控机制仍未明确。本研究旨在通过RNA测序（RNA-sequencing）技术，分析接受金属或聚-L-乳酸（poly-L-lactic acid）封堵器治疗的患者血液样本中的差异表达基因（differentially expressed genes, DEGs），并通过实时荧光定量聚合酶链反应（quantitative real-time polymerase chain reaction, qRT-PCR）对筛选得到的差异基因进行验证，最终明确房间隔缺损封堵治疗后关键介导基因的表达特征。结果显示，分别接受金属封堵器与聚-L-乳酸封堵器治疗的患者中，共鉴定出1045个与1523个显著性差异表达基因。本研究还展示了亚组分析得到的115个重叠差异表达基因。基因表达谱的异同表明，房间隔缺损介入治疗后机体所触发的应答过程既存在非重叠的差异通路，也存在交叉共通的调控模块。其中，共通的机体应答调控基因即为两类封堵器治疗后房间隔缺损患者血液中表达的关键调控基因。基因本体（Gene Ontology, GO）富集分析结果显示，金属封堵器治疗所影响的生物学过程为以CXCR4基因为核心的免疫应答通路；而聚-L-乳酸封堵器治疗的关键调控通路则为核转录mRNA分解代谢过程，以及核糖体蛋白（如RPS26）参与的内质网靶向蛋白转运过程。通过qRT-PCR验证，我们确认在两组治疗方案中，CXCR4、TOB1与DDIT4基因的表达均在术后显著下调至接近治疗前水平。本研究提示CXCR4、DDIT4与TOB1可能在房间隔缺损修复过程的内皮化进程中发挥关键调控作用，为该修复过程的后续分子机制研究提供了新的理论依据。