Correlation Analysis Of PD-1/PD-L1 And RANKL/OPG In Chronic Periapical Inflammation

Objective: In this study,the expression characteristics of programmed cell death molecule-1(PD-1)and its major ligand PD-L1 in peripheral blood and periapical tissues of SD rats with chronic periapical periodontitis with alveolar bone resorption were detected to analyze the mechanism of the association between PD-1/PD-L1 and RANKL/OPG in the process of alveolar bone resorption.Methods: Six SD rats as a group,a group for the blank control group,Four chronic periapical periodontitis models were established.The pathological changes of periapical periodontitis were observed by RVG and HE staining at 1,2,3 and 4 weeks after modeling.Peripheral blood was extracted for flow cytometry analysis of PD-1/PD-L1 ratio changes.Immunohistochemistry and RT-PCR were used to detect the temporal and spatial differential expression patterns of PD-1 and PD-L1 RANKL OPG in the periapical tissues of normal teeth and chronic periapical teeth.One-way analysis of variance between groups was used for data analysis,and Spearman correlation analysis was used for correlation between RANKL/OPG and PD-1/PD-L1.After statistical analysis,the difference was significant(P<0.05).Results:The expression of PD-L1 was detected in lymphocytes of periapical disease,and the expression of PDL-1 was significantly higher than that of white cells in healthy tissues.The level of RANKL/OPG in the periapical tissue was significantly higher than that in the control group,and the expression of RANKL/OPG and PD-1/PD-L1 were positively correlated with time.Conclusion:In chronic periapical inflammation,PD-1/PD-L1 was expressed in peripheral blood and periapical tissues and increased with the development of the disease.RANKL/OPG was detected in periapical tissues and increased with the development of the disease,which was positively correlated with PD-1/PD-L1 in the process of alveolar bone resorption.PD-1/PD-L1 may promote alveolar bone resorption in chronic periapical inflammation...