Identification of Key Immune Infiltration Related Genes Involved in Aortic Dissection Using Bioinformatic Analyses and Experimental Verification

Abstract

Lin Zheng,1,* Yusi Yang,2,* Jie Liu,3 Tianliang Zhao,3 Xin Zhang,3 Lihua Chen3 1Department of Vascular Surgery, the Second Hospital, Shanxi Medical University, Taiyuan, 030001, People’s Republic of China; 2Department of Cardiology, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences Tongji Shanxi Hospital, Taiyuan, 030032, People’s Republic of China; 3Department of Cardiac Surgery, the Second Hospital of Hebei Medical University, Shijiazhuang, People’s Republic of China*These authors contributed equally to this workCorrespondence: Lihua Chen, The Second Hospital of Hebei Medical University, 215 Hepingxi Street, Shijiazhuang, 050000, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected]: Immune microenvironment plays an important role in aortic dissection (AD). Therefore, novel immune biomarkers may facilitate AD prevention, diagnosis, and treatment. This study aimed at mining key immune-related genes and relevant mechanisms involved in AD pathogenesis.Patients and Methods: Key immune cells in AD were identified by ssGESA algorithm. Next, genes associated with key immune cells were screened by weighted gene coexpression network analysis (WGCNA). Then hub immune genes were picked from protein-protein interaction network of overlapped genes from differential expression and WGCNA analyses by cytohubba plug-in. Their diagnostic potential was evaluated in two independent cohorts from GEO database. In addition, the expressions of hub immune genes were determined by quantitative RT-PCR, immunohistochemistry, and Western blotting in dissected and normal aortic tissues.Results: Activated B cells, CD56dim natural killer cells, eosinophils, gamma delta T cells, immature B cells, natural killer cells and type 17 T helper cells were identified as key immune cells in AD. Thereafter, a gene module significantly correlated with key immune cells were found by WGCNA method. Subsequently, KDR, IGF1, NOS3, PECAM1, GAPDH, FLT1, DLL4, CDH5, VWF, and TEK were identified as hub immune cell related genes by PPI network analysis, which may be potential diagnostic markers for AD, as evidenced by ROC curves. Moreover, the decreased expression of VWF in AD was validated at both mRNA and protein levels, and its expression was significantly positive correlated with the marker of smooth muscle cells, ACTA2, in AD. Further immunofluorescent results showed that VWF was colocalized with ACTA2 in aortic tissues.Conclusion: We identified key immune cells and hub immune cell-related genes involved in AD. Moreover, we found that VWF was co-expressed with the smooth muscle cell marker ACTA2, indicating the important role of VWF in smooth muscle cell loss in AD pathogenesis.Keywords: aortic dissection, infiltrating immune cells, diagnosis, smooth muscle cells

Keywords

• aortic dissection
• infiltrating immune cells
• diagnosis
• smooth muscle cells