Co-infection Of Porphyromonas Gingivalis And Influenza Virus On Periodontal Inflammation In Rats And Its Mechanism

ObjectiveBy constructing a rat model of co-infection of Porphyromonas gingivalis(P.gingivalis)and influenza virus(influenza A,H1N1),the relationship between bacterial and viral infections was studied in depth,and the relationship between P.gingivalis and H1N1 was explored.Effect of infection on periodontal inflammation in rats and its mechanism.Provide a theoretical basis for the prevention and clinical treatment of periodontitis and respiratory diseases.Methods1.Fifty SD rats were randomly divided into 5 groups(control group,P.gingivalis group,H1N1 group,P.gingivalis+H1N1 group,P.gingivalis+H1N1+ TAK-242 group)according to the digital random method.The control group was purely ligated with tooth and neck silk thread;P.gingivalis group after dental ligature ligation,periodontal smear P.gingivalis;H1N1 group with dental ligature ligation and H1N1 nose drops;P.gingivalis +H1N1 group dental ligature ligation and periodontal application of P.gingivalis and H1N1 nose.In the P.gingivalis+H1N1+ TAK-242 group,after the dental ligature ligation and periodontal application of P.gingivalis and H1N1 nose,TAK-242(3 mg / kg)was injected into the tail vein.2.Rats in each group were observed for periodontal changes after 4 weeks of treatment.The peripheral blood and periodontal tissues of rats were collected,and the pathological changes of periodontal and lung tissues in each group were analyzed by HE staining.Periodontal exploration was used.Probing depth(PD),plaque index(PLI),sulcus bleeding index(SBI)to assess the extent of periodontal lesions;enzyme-linked immunosorbent assay(ELISA)and RT-PCR was used to detect the expression levels of TNF-α,IL-6,IL-1β and MMP-8 in peripheral blood and periodontal tissue;RT-PCR and Western blot were used to detect the expression of TLR4,NF-κB,My D88 m RNA and protein in periodontal tissue.3.After co-infection with P.gingivalis and H1N1 in rats,TAK-242 was used to block the TLR4 / NF-κB signaling pathway,and PD,PLI,SBI,and MOB values were used to evaluate the degree of periodontal disease;RT-PCR was used to detect periodontal tissue TNF-α,IL-6,IL-1β and MMP-8 expression levels;RTPCR and Western blot detection of TLR4,NF-κB,My D88 m RNA and protein expression in periodontal tissues.Results1.After the rats were infected with P.gingivalis or H1N1,the degree of gingival lesions was significantly higher than that of the control group.The rats in the P.gingivalis + H1N1 group had worse diet and drinking than the H1N1 and P.gingivalis groups.In the P.gingivalis + H1N1 group,there was obvious gingival inflammation.Deep periodontal pockets were seen,the probe was bleeding and raised above the gingival sulcus,and there was obvious loss of adhesion.2.Periodontal and lung tissue HE staining showed that periodontal and lung tissue damage was significantly higher in rats infected with P.gingivalis or H1N1 than in the control group.The inflammation and infiltration of periodontal and lung tissues in P.gingivalis + H1N1 rats were significantly higher than those in H1N1 and P.gingivalis group.3.The PD,PLI,SBI and MOB values in the P.gingivalis group and the H1N1 group were significantly higher than those in the control group(P <0.05).The PD,PLI,SBI and MOB values in the P.gingivalis + H1N1 group were higher than those in the P.gingivalis or H1N1 group(P <0.05).4.The expression levels of inflammatory factors TNF-α,IL-6,IL-1β and MMP-8 in peripheral blood and periodontal tissues in P.gingivalis group and H1N1 group were significantly higher than those in control group(P <0.05).The expression levels of TNF-α,IL-6,IL-1β and MMP-8 in peripheral blood in P.gingivalis + H1N1 group were higher than those in P.gingivalis group or H1N1 group(P <0.05).5.The expression levels of TLR4,NF-κB and My D88 m RNA and protein in periodontal tissues in the P.gingivalis group and the H1N1 group were significantly higher than those in the control group(P <0.05).The expression levels of TLR4,NF-κB and My D88 m RNA and protein in periodontal tissues in the P.gingivalis + H1N1 group were higher than those in the P.gingivalis group or the H1N1 group(P <0.05)6.TAK-242 blocks TLR4 / NF-κB signaling pathway and can reverse the effect of P.gingivalis and H1N1 co-infection on periodontal injury and inflammatory response(P >0.05).ConclusionsP.gingivalis and H1N1 co-infection can significantly increase the periodontal inflammation response and promote the production of inflammatory factors in rats.The mechanism may be related to the activation of the TLR4 / NF-κB signaling pathway.