IADR Abstract Archives
JAK Inhibition Prevents Periodontitis in Vivo and Modulates Bone Turnover in Vitro
Objectives: Many cytokines with biologically functions in inflammatory diseases perform their biological functions through the JAK-STAT signal transduction pathway. Considering the inflammatory nature of periodontal disease, this study evaluated the effects of JAK inhibition on the destruction of periodontal tissues during the progression of periodontitis in vivo, as well as its effects on osteoclasts and osteoblasts in vitro.
Methods: Rats (n= 8 per group) with periodontal disease received the JAK1-3 or JAK-3 inhibitor for 7 days (6.2mg/kg, orally, once a day). Control group animals, with or without ligatures, received the same volume of distilled water. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Il-6 (qPCR). For in vitro analysis, MC3T3-ETC1 cells were treated with different concentrations of JAK-3 and JAK 1-3 inhibitor for 7, 14 and 21 days in order to evaluate mineralization nodule formation through alizarin red staining. To evaluate the effect of JAK inhibition on osteoclastogenesis, RAW 264.7 cells were also plated and treated with different concentrations of inhibitors in the presence of RANKL, and the number of osteoclasts identified by fluorescence microscopy. Data were analyzed using GraphPad Prism 6.0 (GraphPad Software Inc.). ANOVA with Tukey's post-hoc test for paired comparisons. The significance level was set at 95% (p < 0.05) in all analyses.
Results: JAK1-3 and -3 inhibition significantly reduced bone resorption in rats, as well as the amount of inflammatory infiltrate in gingival tissues. Il-6 expression was prevented only by administration of JAK-3 (p<0.05). In vitro, both inhibitors stimulated mineralized matrix formation and inhibited osteoclast differentiation (p<0.05).
Conclusions: These results suggest that the modulation of this signaling pathway may be a promising therapeutic strategy for periodontitis and other osteolytic diseases.
Methods: Rats (n= 8 per group) with periodontal disease received the JAK1-3 or JAK-3 inhibitor for 7 days (6.2mg/kg, orally, once a day). Control group animals, with or without ligatures, received the same volume of distilled water. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Il-6 (qPCR). For in vitro analysis, MC3T3-ETC1 cells were treated with different concentrations of JAK-3 and JAK 1-3 inhibitor for 7, 14 and 21 days in order to evaluate mineralization nodule formation through alizarin red staining. To evaluate the effect of JAK inhibition on osteoclastogenesis, RAW 264.7 cells were also plated and treated with different concentrations of inhibitors in the presence of RANKL, and the number of osteoclasts identified by fluorescence microscopy. Data were analyzed using GraphPad Prism 6.0 (GraphPad Software Inc.). ANOVA with Tukey's post-hoc test for paired comparisons. The significance level was set at 95% (p < 0.05) in all analyses.
Results: JAK1-3 and -3 inhibition significantly reduced bone resorption in rats, as well as the amount of inflammatory infiltrate in gingival tissues. Il-6 expression was prevented only by administration of JAK-3 (p<0.05). In vitro, both inhibitors stimulated mineralized matrix formation and inhibited osteoclast differentiation (p<0.05).
Conclusions: These results suggest that the modulation of this signaling pathway may be a promising therapeutic strategy for periodontitis and other osteolytic diseases.