Correlation Between Salivary Flora And TLRs/NF-?B P65 Signaling Pathway In Patients With Oral Lichen Planus

OBJECT: The diversity and community differences of oral salivary flora and the expression of Toll-like receptors/nuclear factor-?B p65(TLRs/NF-?B p65)signaling pathway-related inflammatory cytokines in patients with oral lichen planus(OLP)were detected and analyzed.And the correlation between flora and inflammatory factors was analyzed to study the molecular mechanism of the two in the process of OLP lesions.METHODS: Patients of non-erosive oral lichen planus(NEOLP group,n = 17)and erosive oral lichen planus(EOLP group,n = 17)were selected.The severity of the disease was scored by REU,saliva and tissue samples were collected,and 17 age-and sex-matched volunteers were selected as the healthy control group(HC group,n = 17).A part of saliva was used to extract DNA for polymerase chain reaction amplification,and the 16 S rRNA V3-4 hypervariable region was sequenced by using Miseq high-throughput sequencing platform.The characteristics of saliva flora structure and diversity from above three groups were compared based on microbial diversity analysis.The other part of saliva was used in enzyme-linked immunosorbent assay(ELISA)to determine the expression of IL-6 and TNF-?.Immunohistochemical staining(IHC)was used to detect the expression of TLR2,TLR4 and NF-?B p65 in tissues.Pearson correlation analysis was used to detect the correlation between salivary flora and TLR2,TLR4,NF-?B p65,IL-6,TNF-? and REU with IL-6,TNF-?.RESULTS: 1.The flora analysis found that the ? diversity of the NEOLP group was lower than that of the HC group(P < 0.05).And the microbial community structures in HC group were distinguished from those in NEOLP and EOLP group respectively(P < 0.05);while those were not significantly different between the NEOLP and EOLO group(P > 0.05).In addition,Saliva flora structure in HC group is more similar and conservative compared with the diseased groups(P < 0.05).And abnormal expression microorganisms in NEOLP and EOLP group were identified(P < 0.05).The results showed that compared with the HC group,the relative abundance of Rothia and Streptococcus was increased,and the relative abundance of Derxia,Haemophilus and Pseudomonas was reduced in the NEOLP group.However,compared to the HC group,only the relative abundance of Derxia,Haemophilus and Pseudomonas was reduced in the EOLP group.Furthermore,the relative abundance of Atopobium and Solobacterium in the NEOLP group was higher compared with the EOLP group.2.Immunohistochemical staining showed that the expression levels of TLR2,TLR4 and NF-?B p65 in the EOLP and NEOLP groups were significantly higher than those in the HC group(P < 0.05),while there was no statistically significant difference between EOLP group and NEOLP group(P > 0.05).ELISA showed that the concentration of IL-6 and TNF-? in the NEOLP and EOLP groups was significantly higher than that in the HC group(P < 0.05).Compared with the EOLP group,the expression levels of these 2 inflammatory cytokines were similar in the NEOLP group(P > 0.05).3.Pearson correlation analysis found that the salivary flora diversity in the NEOLP group was significantly negatively correlated with the expression level of NF-?B p65.And the relative abundance of streptococcus was positively correlated with the expression level of TLR2.In addition,the REU score of the EOLP group was positively correlated with the concentration of IL-6.CONCLUSION: 1.OLP patients' saliva flora diversity,flora structure,and species composition ratio changed,breaking the original flora balance state,and the phenomenon of flora imbalance occurred.2.The imbalance of non-erosive OLP patients' flora further activates the TLR2 / NF-?B p65 signaling pathway and promotes the occurrence of inflammatory reactions in oral lesions.Both of them play a role in the formation of OLP lesions.3.IL-6 may play a role in amplifying the inflammatory response of erosive OLP and promoting the progression of the lesion.