| Objectives: Mesenchymal stem cells(MSCs)mediated periodontal tissue regeneration is considered a promising method for periodontitis treatment and the key to the functional reconstruction of peri-implant supportive tissue.The moleclar mechanism of MSCs functional regulation remains unclear,thus limiting the application.Our previous study discovered Periostin(POSTN)promoted the migration and osteogenic differentiation of periodontal ligament mesenchymal stem cells(PDLSCs),but it is still unclear whether POSTN could restore the regenerative potential of PDLSCs under inflammatory conditions.In this study,we investigated the effects and mechanism of POSTN on PDLSCs under inflammatory conditions.Materials and Methods: PDLSCs were isolated from periodontal ligament tissue.10 ng/m L TNF-α was used to mimic inflammatory condition.Lentivirus POSTN sh RNA was used to knockdown POSTN.Recombinant Human POSTN(rh POSTN)was used to stimulate PDLSCs.Scratch assay was used to analyze cell migration.Alkaline phosphatase(ALP)activity,Alizarin Red staining and the expressions of osteogenesis related genes were used to investigate osteogenic differentiation potentials.Western blot analysis was used to detect the MAPK and AKT signaling pathways.Results: After 10 ng/m L TNF-α treatment,knockdown of POSTN impeded scratch closure,inhibited ALP activity and mineralization in vitro,and decreased the expressions of RUNX2,OSX,OPN,and OCN in PDLSCs,while 75 ng/m L rh POSTN significantly accelerated scratch closure,enhanced ALP activity and mineralization in vitro,and increased the expressions of RUNX2,OSX,OPN,and OCN.In addition,knockdown of POSTN inhibited the expression of phosphorylated c-Jun N-terminal kinase(p-JNK),while 75 ng/m L rh POSTN increased the expression of p-JNK in PDLSCs with TNF-α treatment.Furthermore,inhibition of JNK by its inhibitor,SP600125,dramatically blocked POSTN-enhanced scratch closure,ALP activity and mineralization in PDLSCs.Conclusions: Our results discovered that POSTN might promote the migration and osteogenic differentiation potentials of PDLSCs via JNK pathway,and provided insight into the mechanism underlying the MSCs biology under inflammatory conditions,and identified a potential target for improving periodontal tissue regeneration and the functional reconstruction of peri-implant supportive tissue. |
