Lu Wenzhao, Li Yao, Dai Yan, Chen Keping
State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Arrhythmia Center, Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Front Cardiovasc Med. 2022 Jun 29;9:900810. doi: 10.3389/fcvm.2022.900810. eCollection 2022.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable life-threatening myocardial disease characterized by ventricular arrhythmias and sudden cardiac death. Few studies used RNA-sequencing (RNA-seq) technology to analyze gene expression profiles, hub genes, dominant pathogenic processes, immune microenvironment in ARVC. This study aimed to explore these questions integrated bioinformatics analysis.
RNA-sequencing datasets of GSE107475, GSE107311, GSE107156, and GSE107125 were obtained from the Gene Expression Omnibus database, including right and left ventricular myocardium from ARVC patients and normal controls. Weighted gene co-expression network analysis identified the ARVC hub modules and genes. Functional enrichment and protein-protein interaction analysis were performed by Metascape and STRING. Single-sample gene-set enrichment analysis (ssGSEA) was applied to assess immune cell infiltration. Transcription regulator (TF) analysis was performed by TRRUST.
Three ARVC hub modules with 25 hub genes were identified. Functional enrichment analysis of the hub genes indicated that myocardial fibrosis was the dominant pathogenic process. Higher myocardial fibrosis activity existed in ARVC than in normal controls. A complex immune microenvironment was discovered that type 2 T helper cell, type 1 T helper cell, regulatory T cell, plasmacytoid dendritic cell, neutrophil, mast cell, central memory CD4 T cell, macrophage, CD56dim natural killer cell, myeloid-derived suppressor cell, memory B cell, natural killer T cell, and activated CD8 T cell were highly infiltrated in ARVC myocardium. The immune-related hub module was enriched in immune processes and inflammatory disease pathways, with hub genes including CD74, HLA-DRA, ITGAM, CTSS, CYBB, and IRF8. A positive linear correlation existed between immune cell infiltration and fibrosis activity in ARVC. NFKB1 and RELA were the shared TFs of ARVC hub genes and immune-related hub module genes, indicating the critical role of NFκB signaling in both mechanisms. Finally, the potential lncRNA-miRNA-mRNA interaction network for ARVC hub genes was constructed.
Myocardial fibrosis is the dominant pathogenic process in end-stage ARVC patients. A complex immune microenvironment exists in the diseased myocardium of ARVC, in which T cell subsets are the primary category. A tight relationship exists between myocardial fibrosis activity and immune cell infiltration. NFκB signaling pathway possibly contributes to both mechanisms.
致心律失常性右室心肌病（ARVC）是一种遗传性的危及生命的心肌疾病，其特征为室性心律失常和心源性猝死。很少有研究使用RNA测序（RNA-seq）技术来分析ARVC中的基因表达谱、枢纽基因、主要致病过程和免疫微环境。本研究旨在通过综合生物信息学分析来探索这些问题。
从基因表达综合数据库中获取GSE107475、GSE107311、GSE107156和GSE107125的RNA测序数据集，包括ARVC患者和正常对照的右心室和左心室心肌。加权基因共表达网络分析确定了ARVC枢纽模块和基因。通过Metascape和STRING进行功能富集和蛋白质-蛋白质相互作用分析。应用单样本基因集富集分析（ssGSEA）评估免疫细胞浸润。通过TRRUST进行转录调节因子（TF）分析。
鉴定出三个含有25个枢纽基因的ARVC枢纽模块。枢纽基因的功能富集分析表明心肌纤维化是主要的致病过程。ARVC中的心肌纤维化活性高于正常对照。发现了一个复杂的免疫微环境，其中2型辅助性T细胞、1型辅助性T细胞、调节性T细胞、浆细胞样树突状细胞、中性粒细胞、肥大细胞、中枢记忆CD4 T细胞、巨噬细胞、CD56dim自然杀伤细胞、骨髓来源的抑制细胞、记忆B细胞、自然杀伤T细胞和活化的CD8 T细胞在ARVC心肌中高度浸润。免疫相关枢纽模块在免疫过程和炎症性疾病途径中富集，枢纽基因包括CD74、HLA-DRA、ITGAM、CTSS、CYBB和IRF8。ARVC中免疫细胞浸润与纤维化活性之间存在正线性相关。NFKB1和RELA是ARVC枢纽基因和免疫相关枢纽模块基因的共同TF，表明NFκB信号在这两种机制中都起关键作用。最后，构建了ARVC枢纽基因的潜在lncRNA-miRNA-mRNA相互作用网络。
心肌纤维化是晚期ARVC患者的主要致病过程。ARVC病变心肌中存在复杂的免疫微环境，其中T细胞亚群是主要类别。心肌纤维化活性与免疫细胞浸润之间存在密切关系。NFκB信号通路可能在这两种机制中都起作用。
