IL-7 Maintain Periodontal Ligament Stem Cells Self-renewal And Osteogenetic Differentiation Potential Involving In JAK/STAT Signaling Pathway

Objective:Resently,periodontal disease is a common cause of periodontal tissue defecting,which eventually lead to teeth loss.However,The traditional treatment is difficult to obtain true regeneration of periodontal support tissues,so it is quite necessary to explore new treatment.The periodontal ligament stem cells(PDLSCs)are part of adult stem cells from the periodontal ligament,has the strong ability of self-renewal,and the capable of differentiating into a variety of cell types,is the most ideal and reliable seed cells for periodontal tissue regeneration?Periodontal ligament stem cells(PDLSCs)are mainly obtained from the extracted tooth for orthodontic treatment or third molar,so it is very difficult to obtain sufficient PDLSCs to regenerate injured periodontal tissue.Therefore,it is important to detect the self-renewal mechanism of PDLSCs.At present,there are a number of studies have demonstrated that the periodontal ligament stem cells express IL-7 receptor,and more express than bone marrow mesenchymal stem cells or dental pulp stem cells,its ligands IL-7 is a crucial cytokine involved in T-cell and B-cell proliferation,survival and development.however,As yet,the physiological significance of IL-7 about non-lymphoid cells has not been fully defined,especially about the periodontal ligament stem cells.The purpose of this study is to explore IL-7 effecting the periodontal ligament stem cell on self-renewal ability and osteogenesis ability of differentiation,and discusses the influence of IL-7 mechanism of the impact of the periodontal ligament stem cell self-renewal ability.Methods:Firstly,to detect the periodontal ligament stem cells to express IL-7 protein and mRNA by ELISA and RT-PCR method.Secondly,the periodontal ligament stem cells culture in the medium containing 100 ng/ml IL-7(test group1),the common culture medium(control group),and containing 5 ug/ml anti IL-7 antibodies(test group2).the cultures of P3?P6?P9 were compared between the clone formation ability,proliferation,percentage of mesenchymal stem cells and osteogenesis ability.Finally,Western bolt test the phosphorylation of STAT-5 and AKT of the periodontal ligament stem cells which culture in IL-7 or anti-IL-7Ab.and Western bolt test the antiapoptotic proteins Bcl-2,Mcl-2 and apoptosis protein Bim,Bax of the periodontal ligament stem cells which culture in IL-7 or anti-IL-7Ab.Results:1,the periodontal ligament stem cells express IL-7 protein.2,the test group 1 showed a highest CFU-F numbers than control group and test group2,And the test group2 showed a lowest CFU-F numbers than control group and test group1(p<0.05,there is statistical significance);the test group 1 showed a highest proliferation rate than the control group test group2,And the test group2 showed a lowest proliferation rate than the control group test group1(p<0.05,there is statistical significance);the test groupl showed a highest the percentage of stem cell than the control group test group2,And the test group2 showed a lowest the percentage of stem cell than the control group test group1(p<0.05,there is statistical significance).3,the test groupl showed a highest osteogenesis ability of differentiation of stem cells than the control group test group2,And the test group2 showed a lowest osteogenesis ability of differentiation of stem cells than the control group test group1(p<0.05,there is statistical significance).4,After IL-7 stimulation,stem cells express p-STAT-5 and antiapoptotic proteins the Bcl-2,Mcl-2 significantly enhanced,and Bim,Bax apoptosis protein significantly decreased.Conclusion:IL-7 through the JAK/STAT signaling pathway up-regulat antiapoptotic proteins and down-regulat apoptosis protein to remain self-renewal and differentiation ability of the periodontal ligament stem cell.