Differentially expressed genes in chronic periodontitis and the correlation with disease severity / 国际生物医学工程杂志

ABSTRACT

Objective:To study the differentially expressed genes in chronic periodontitis (CP) and to explore the correlation with disease severity.Methods:Gene expression profile data associated with CP were screened in the Gene Expression Omnibus (GEO) database and analyzed with GEO2R online software to create volcano maps. Kyoto Encyclopedia of Genes and Genomes (KEEG) and Gene Ontology (GO) analyses were performed on the screened CP-associated differentially expressed genes to predict their possible functions and signaling pathways. The protein-protein interaction database (STRING) was used to analyze the interaction relationships between the encoded proteins of the screened CP-related differentially expressed genes. Cytohubba software was used to identify key genes in the signaling pathway. One120 CP patients and 40 healthy controls were selected. The screened CP-related genes were validated by the real-time polymerase chain reaction (q-PCR) method.Results:A total of 1 151 CP differentially expressed genes that met the requirements were screened. These genes were mainly enriched in the GO pathway for positive regulation of granulocyte differentiation, helper T-cell differentiation, leukocyte aggregation, regulation of acute inflammatory response, chemokine-mediated and endoplasmic reticulum unfolded protein response, as well as in the KEGG pathway for NFB pathway, chemokine pathway, cytokine receptor interaction, leukocyte transendothelial migration pathway, B-cell receptor pathway, Toll-like receptor pathway, etc. The protein-protein interaction network was constructed using the screened CP-related differentially expressed genes, which included 78 nodes and 496 links, with a mean aggregation coefficient and mean connectivity of 0.69 and 12.7, respectively. Cytohubba analysis showed that Sell was a key gene in the signaling pathway, and its relative expression levels in the gingival fluids of the three CP groups with different degrees(1.14±0.46, 0.86±0.41, 0.52±0.46) was significantly lower than that of the control group (1.50±0.65) (all P<0.05). The area under the ROC curve (AUC) of subjects diagnosed with CP using Sell expression levels in gingival fluid was 0.79 (95% CI 0.71 to 0.86). The AUC values were greater than 0.65 at 95% CI when Sell was used as a biological marker to evaluate the severity of CP. Conclusions:CP-related differentially expressed genes are mainly enriched in the number of pathways associated with the inflammatory response of periodontitis. The expression levels of Sell genes were significantly reduced in the gingival sulcus fluid of CP patients and correlated with the severity of the disease. The Sell genes are expected to be a biomarker for CP grading.