Expression of Inflammatory Mediators in Periodontitis Over Established Diabetes: an Experimental Study in Rats

BACKGROUND: Diabetes mellitus is characterized by hyperglycemia ensuing from deficiencies in insulin action, secretion, or both. Hyperglycemia has wide-ranging molecular and cellular effects, leading to oxidative stress, up-regulation of pro-inflammatory responses, and vascular changes. OBJECTIVES: The aim of this study was to evaluate the expressions of inflammatory markers involved in periodontal destructive process occurring in diabetes, periodontitis (PD), and both coexisting conditions. METHODS: A rat model was carried out using streptozotocin (STZ) to induce diabetes and Lipopolysaccharides (LPS) with teeth ligature to mimic periodontitis. The animals were distributed randomly into seven groups (n=12) and treated for 10 weeks with alternation between diabetes and PD. The relative quantification analysis of inflammatory markers expression: CRP, MMP-2-14, TIMP-2, IL-4, IFN-γ, was performed at the end of the experiments using western blot after protein isolation from periodontal tissue surrounding the ligation. RESULTS: The data showed that CRP, MMP-2, MMP-14, TIMP-2, and IFN-γ are involved in the process of periodontal inflammation associated with diabetes. A significant increase (p<0.05) in the expression of inflammatory markers was detected when PD is associated with preexisting diabetes in comparison with diabetes superimposed on preexisting PD. CONCLUSION: This study demonstrated that already established diabetes worsens periodontitis more than diabetes upcoming on existing periodontitis.