OPG And RANKL Expressions And Reciprocity In Alveolar Bone Of Rats Periodontitis With Type 2 Diabetetic

Objective:Rats experimental periodontitis, type 2 diabetes, periodontitis with type 2 diabetes model were established respectively. Immunohistochemistry was used to detect the expression level of OPG and RANKL in alveolar bone(maxillary second molar) of each group. After injecting recombinant human osteoprotegerin (rhOPG) into the periodontal lesions of rats experimental periodontitis, the expression level of the two cytokines were detected again by immunohistochemistry. The aim of the research is to clear whether OPG and RANKL may play a role in periodontitis and type 2 diabetes pathogenesis or not, so as to provide the foundation of appling rhOPG in the treatment of periodontitis.Methods:Rats were randomly divided into four groups(A,B,C and D), rats from group A were given wire around the cervix of the second maxillary molars and provided with drinking water containing 10% glucose for 8 weeks. Rats of group B were fed with high sucrose-fat diet for 6 weeks, then low-dose STZ were injected to establish rat model of type 2 diabetic. Method A and B were used together to establish the type 2 diabetic with periodontitis model for rats of group C. Group D were health group (no treatment). Rats were killed after models established successfully. Take the ipsilateral maxillary alveolar bones from rats and soak them in 4% paraformaldehyde solution for 24 hours, and then decalcificate them in 10% EDTA solution for 2 months. Immunohistochemistry was used to detect the expression of OPG and RANKL in alveolar bone(second maxillary molar) of each group. Taking 10 rats from group A separately, removing the ligature wire around the cervix of the second maxillary molars and performing subgingival curettage.These 10 rats were randomly divided into 2 groups(rhOPG and control group), rats from group of rhOPG were injected by rhOPG into lesions periodontium 2 times/week, while control group were not treatment. Kill the rats and take the ipsilateral maxillary alveolar bone to detect the change of expression of OPG and RANKL in alveolar bone..Results:1. The expression of OPG in healthy alveolar bone of rats were the highest and were reduced in type 2 diabetic group, simple periodontitis group and type 2 diabetic periodontitis group in turn. There was no difference between simple periodontitis group and type 2 diabetic periodontitis group(P>0.05), while there were significent differences among the others(P<0.05). Expression of RANKL in alveolar bone of type 2 diabetic periodontitis rats were the highest and were reduced in simple periodontitis group, type 2 diabetes group and the healthy group in turn. There was no difference between simple periodontitis group and type 2 diabetic periodontitis group(P>0.05), while there were significent differences among the others(P<0.05).2. The periodontal initial therapy together with local injection of rhOPG can not only decrease the RANKL expression but also can increase the OPG expression in alveolar bone of periodontitis, and the differences were statistically significant(P<0.05). While periodontal initial therapy can only play a role for decreasing the RANKL expression in alveolar bone(P<0.05), but do nothing for the expression of OPG.(P>0.05).Conclusion:1. These results showed that the imbanlance of OPG and RANKL in alveolar bone may be main reason resulting in periodontitis, RANKL/OPG and the severity of periodontitis were positive correlation. Type 2 diabetic as the general factor may cause the host high susceptibility to periodontitis and accelerate the imbalance of OPG and RANKL, Therefore, it may promote the occurrence and development of periodontitis.2. Periodontal initial therapy may play a important role only for decreasing the RANKL expression in alveolar bone.The periodontal initial therapy together with local injection of rhOPG can not only decrease the RANKL expression in alveolar bone of periodontitis but also can increase the OPG expression. It suggests that the studies will provide the experimental basis for understanding the reason of periodontitis with type 2 diabetic and improving the therapy of periodontitis.