Role Of Hmgb1 In Macrophage Polarization In Smoking-Related Periodontitis

To investigate the role of HMGB1 in experimental passive smoking periodontitis mice in vivo and the effects of HMGB1 in macrophages polarization in vitro. 1. After 8 weeks of ligation and/or passive smoking, periodontal tissues were evaluated using histology,micro-CT,TRAP staining, and immunohistochemistry. 2. Immunofluorescence staining and ELISA were used to determine the translocation and release of HMGB1 in macrophages stimulated by CSE and Pg-LPS. 3.The mRNA expression of M1 markers (iNOS, TNF-α, IL-6) and M2 markers (ARG-1, RELM-α, MRC-1) in macrophages was measured using RT-PCR. 4. Western blot and flow cytometry were used to detect the expression of HMGB1-specific receptors in macrophage. 1. Periodontal inflammation,HMGB1 translocation and secretion,macrophage activation and polarization of Group Periodontitis+Smoking was significantly severe than Group Periodontitis; and less severe after antiHMGB1 injection. 2.CSE and Pg-LPS can significantly increase HMGB1 expression and translocated from the nucleus to the cytoplasm. 3.Compared to Group N, M1 markers were significantly increased in the Group Pg-LPS and Group CSE+Pg-LPS (P<0.01). There were no significant differences in the gene expression of M2 markers among all group except Group IL-4. 4.Compared to Group N, the expression of TLR4 were significantly increased in Group Pg-LPS and Group CSE+Pg-LPS, lower in Group CSE+Pg-LPS+antiHMGB1. HMGB1 might exacerbate periodontal inflammation and alveolar bone resorption in cigarette Smoking-related Periodontitis through macrophages polarization via TLR4.