A bioinformatics approach revealed the transcription factors of Helicobacter pylori pathogenic genes and their regulatory network nodes

Abstract

Background: Helicobacter pylori is a chronic pathogenic bacteria that causes gastric mucosal damage through various host-related and pathogen-related factors. Thus, a single gene research cannot fully explain its pathogenicity. Purpose of the study: It is necessary to establish a Helicobacter pylori pathogenic gene transcription factor regulatory network (TFRN) and study its central nodes.

Results: The expression data of Helicobacter pylori pathogenic genes were obtained through GEO Datasets of NCBI. The genes were screened using linear model-empirical Bayesian statistics in R language Limma package combined with the conventional t-test; the results identified 1231 differentially expressed genes. The functional analysis (gene ontology-analysis) and signal pathway analysis (pathway-analysis) of differentially expressed genes were performed using the DAVID and KEGG databases, respectively. The pathogenic gene regulatory network was constructed by integrating transcriptional regulatory element database (TRED); the disease-related analysis of the pathogenic genes was conducted using the DAVID annotation tool. Five pathogenic genes (Nos2, Il5, Colla1, Tnf, and Nfkb1) and their transcription factors (Jun, Cebpa, Egrl, Ppara, and Il6) were found to suppress the host immune function and enhance the pathogenicity of Helicobacter pylori by regulating the host immune system.

Conclusions: This effect was largely mediated via three signaling pathways: Tnf pathway, PI3K Akt pathway, and Jak–STAT pathway. The pathogenicity of Helicobacter pylori is closely related to the body's immune and inflammatory system. A better understanding of the correlation of the pathogenic factors with the host immune and inflammatory factors may help to determine the precise pathogenic mechanism of H. pylori infection.