Abstract: Objective:To observe the expression of Beclin1, LC3 and P62 in periodontitis rat liver tissue, and to investigate the role of Beclin1-mediated autophagy in periodontitis related liver injury.Methods: Twelve eight-week-old male Wistar rats were randomly selected and divided into two groups: one group was control group, the other group was periodontitis group (n=6).In the periodontitis group, the periodontitis model was established by ligating orthodontic wire, while in the control group, no treatment was done. After 8 weeks, periodontal clinical indexes (SBI, PD, TM) of maxillary first molars of rats in each group were examined and recorded. Detect serum liver function indicators such as ALT and AST.HE staining and oil red O staining were used to detect periodontal histopathology, liver histopathology and fatty changes. qRT-PCR was used for gene determination of Beclin1, LC3 and P62 in liver tissue, and Western blot was used for protein determination of Beclin1, LC3 and P62. Results:Compared with the control group, the clinical indicators (SBI, PD, TM) and HE staining of periodontal tissue in the periodontitis group showed obvious inflammatory response.Liver function index ALT, AST and so on increasing. The results of HE staining and oil red O staining of liver tissue showed vascular steatosis in liver tissue.The mRNA and protein expression levels of Beclin1 and LC3 decreased, while the mRNA and protein expression levels of p62 increased. Conclusion:Beclin1 - mediated autophagy dysfunction may be part of the mechanisms of periodontitis - related liver injury.

Key words: Periodontitis, liver injury, autophagy, Beclin1