Immunohistochemical Study Of HMGB1 In The Periodontal Tissue Occurred To Occlusal Traumatism In Ovariectomized Mice

Background High mobility group box protein-1(HMGB1)is seen as an important proinflammatory cytokine which bonding with periodontisis.Occlusal trauma(OT)is a kind of damage which resulted from unnormal or incoordinated occlusion,and play an core role in adjusting the development of periodontosis.Periodontosis is an inflammatory disease characterized by loss of connective tissue and alveolar bone.However,Postmenopausal osteoporosis will led to a high risk of periodontosis by lack of estrogen which causing decrease of bone.Occlusal trauma threaten the person who suffering osteoporosis seriously by effecting their periodontal tissue.Objective The aim of this research is to investigate the High mobility group box protein 1(HMGB1)expression in ovariectomized mice’s periodontal tissue during occlusal traumatism.Methods Twenty-four female Kunming mice were divided into four groups randomly:(1)control(CON);(2)occlusal traumatism(OT);(3)OVX(OVX);(4)OVX+occlusal traumatism(OVX+OT).The mice in OVX and OVX+OT group had ovariectomy at the beginning of the experiment,and then the OT and OVX+OT were subjected by occlusal traumatism at the 7th week after the surgery.All the mice were killed to make paraffin sections at the 8th week.Immunohistochemistry were applied to study the expression of HMGB1,computerized image analysis system was used to analyze the result.Results 1.The HE staining showed that mice which subjected by occlusal traumatism displayed disorder and tearing periodontal membrane fiber.2.More THAP-positive osteoclasts were found in OVX+OT group than other groups,OT and OVX group’s expression were a little more than CON group’s in TRAP staining,whereas there was no significant difference between the two groups.3.The expression of HMGB1 in OVX+OT group was highest.OT and OVX group’s expression were a little more than CON group’s in immunohistochemistry of HMGB1,whereas there was no significant difference between the two groups.Conclusions Occlusal trauma and defect of estrogen have a synergetic effect to the expression of HMGB1 in periodontal tissue,further more,there is a positive correlation between the expression of HMGB1 and positive osteoclasts.It gives us a hint that HMGB1 plays an important role in adjusting the restructuring of the periodontal tissue.The person who is suffering the osteoporosis will face a higher risk of periodontal tissue damage than normal people under the effect of the similar occlusal trauma.The research provided a theoretic foundation to study the pathogenesis and cell signaling pathway of the periodontosis for controlling the process of the disease.In additional,the result of this research is valuable to estimate the incidence of the peri-implantitis which is caused by tooth implant on osteoporosis patients.