Curcumin Inhibits Autophagy of Periodontal Ligament During Orthodontic Tooth Movement by Activating GSK-3β/β-catenin Pathway
Objective To observe the effect of curcumin on orthodontic tooth movement(OTM)and its potential mechanism.Methods Thirty rats were randomly divided into 5 groups:normal group,model group,curcumin 40,80,160 mg/kg groups,with 6 rats in each group.In addition to the normal group,the other groups of rats were constructed OTM model.After intervention,the displacement of maxilla was observed by micro-CT tomography.The pathological morphology of maxillary tissue was observed by hematoxylin-eosin(HE)staining.The apoptosis of periodontal ligament cells was observed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)staining.The level of reactive oxygen species(ROS)in periodontal ligament was determined by flow cytometry.The content of malondialdehyde(MDA)and the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in periodontal ligament tissue were measured by microplate reader.Immunofluorescence staining and Western Blot were used to detect the expressions of glycogen synthase kinase 3β(GSK-3β)/β-catenin pathway-related proteins and autophagy levels in periodontal ligament tissues.Results Compared with the model group,the number of OTM-induced periodontal ligament fibroblasts was increased,the levels of MDA and ROS in periodontal ligament were decreased,the activities of SOD and GSH-Px were increased,the protein expressions of autophagic indexes including Beclin1,Lamp and LC3B in periodontal ligament were decreased,and the expressions of p-GSK-3β/GSK-3β and β-catenin in periodontal ligament was decreased in curcumin groups(all P<0.05).Conclusion Curcumin may inhibit oxidative stress by blocking the GSK-3β/β-catenin pathway,thereby inhibiting periodontal membrane autophagy during orthodontic tooth movement.