Exploring biomarkers of intestinal ischemia reperfusion injury based on bioinformatics

Abstract

Background: Intestinal ischemia reperfusion injury (IIRI) is relevant to crucial clinical manifestations. Hence, it was vital to screen the important biomarkers for the diagnosis and treatment of IIRI. Methods: The transcript sequence data was yielded to screen out differentially expressed genes (DEGs) in IIRI. WGCNA was conducted to select key module genes related to IIRI vs normal groups. Venn Diagram was utilized to identify candidate genes. Further, PPI network of candidate genes was established to show the interaction relationship. LASSO and SVM-RFE analysis were implemented to screen biomarker of IRI. We finally performed immune infiltration and functional enrichment analysis based on biomarkers. Finally, the vital biomarkers ofin IIRI were verified by quantitative PCRand immunohistochemical. Results: We identified 2919 DEGs and 1040 key module genes. Then, 483 candidate genes were obtained via venn diagram. Subsequently, 5 biomarkers (Ccl7, Cd14, Cxcl1, Hmox1 and Nfkbia) were identified via machine learning. Moreover, we found that these biomarkers was mainly enriched in the ‘reactome activation of NF -kappa-B in B cells’ pathway. We also found that 5 biomarkers were significantly positively correlated with actived DC, M2 Macrophage and Th2 cells, whereas all biomarkers was negatively correlated with immature DC, gammadelta T cells. For expression validation of the biomarkers, we observed higher expression of Ccl7,Cd14, Cxcl1, Hmox1 and Nfkbia in IIRI group in the sequencing data. we validated the expression in mouse tissue by RT-qPCR and immunohistochemical, which all tested and verified the conclusion of sequencing data analysis. Conclusion: Overall, we obtained 5 biomarkers (Ccl7, Cd14, Cxcl1, Hmox1 and Nfkbia), which laid a theoretical foundation for the mechanism and clinical research of IIRI.