Identification And Analysis Of Necroptosis-related Genes In COPD By Bioinformatics And Experimental Verification

Objective: Chronic obstructive pulmonary disease(COPD)is a heterogeneous and complex progressive inflammatory disease.Necroptosis is a newly identified type of programmed cell death that contributes to the pathogenesis of COPD.However,the role and mechanism of necroptosis in COPD is unclear.This study aimed to identify necroptosis-related genes in COPD and explore the interaction of necroptosis and immune infiltration through bioinformatics.Methods: First,differentially expressed necroptosis-related genes in COPD were identified in the microarray dataset GSE38974 with R software.Gene Ontology enrichment,Kyoto Encyclopedia of Genes and Genomes pathway enrichment,and protein–protein interaction(PPI)analysis were applied for the necroptosis-related differentially expressed genes.The hub genes were screened with Cytoscape software.Then,the CIBERSORT algorithm was used to analyze immune cell infiltration in lung tissues.Spearman correlation analyses were conducted between hub genes and infiltrated immune cells.Finally,the hub genes were verified in the sequencing dataset GSE57148 and an experimental emphysema mouse model.The diagnostic efficacy was evaluated by ROC curve analysis.We also constructed a TF–miRNA coregulatory network using Network Analyst and explored candidate drugs with Enrichr.Results: Forty-nine differentially expressed necroptosis-related genes were detected that were primarily engaged in cell death and inflammatory immune response pathways.Infiltration of CD8+ T cells and M2 macrophages in COPD lung tissue was relatively reduced,while that of M0 macrophages was upregulated.We identified 10 necroptosisrelated hub genes,including CASP8,IL1 B,HSP90AA1,RIPK1,MLKL,IKBKB,XIAP,TNFRSF1 A,FADD and CFLAR,and the hub genes were significantly associated with infiltrated immune cells.Furthermore,7 hub genes,CASP8,IL1 B,RIPK1,MLKL,XIAP,TNFRSF1 A,and CFLAR,were validated.CFLAR(AUC=0.852)was considered to have the best COPD-diagnosing capability.TF and miRNA interactions with common hub genes were identified,which consist of 56 TFs and 105 miRNAs.Several related potentially therapeutic molecules were also identified for COPD,including dehydroxymethylepoxyquinomicin(DHMEQ),anacardic acid,1’-acetoxychavicol acetate,pregna-4,17(20)-diene-3,16-dione,and lonafarnib.Conclusion: Our analysis reveals that necroptosis occurs in COPD pathogenesis and the expression levels of necroptosis-related genes significantly differ between COPD and normal lung tissues.Necroptosis-related genes correlate with immune cell infiltration,which indicates that necroptosis may participate in the development of COPD by interacting with the immune response.CFLAR has the best capability to diagnose COPD with excellent specificity and sensitivity.Construction of a TF-miRNA coregulatory network and potential therapeutic drug prediction pave the way for future investigation of COPD pathogenic mechanisms and improvement of COPD therapeutic strategies.