Objective To explore the effect of Notch1 signal pathway on the osteogenic differentiation in human periodontal ligament stem cells(PDLSCs) under dynamic strain.Methods PDLSCs were separated from freshly extracted teeth then identified and prolifed.Notch1 signal pathway was regulated by chemicals.Dynamic strains were applied to PDLSCs with the tension plus system.Then Notch1 signal pathway key factor Notch intracellular domain(NICD),osteoblastic related indexes alkaline phosphatase(ALP) and bone morphogenetic proteins 2 (BMP2) were detected by western blot expression.The deformation rate of stress parameters was 0 to 12%,and the frequency was 0.1 Hz.The loading time was 0 h,6 h,12 h and 24 h.Results As Notch1 signal pathway was activated,the expression of osteogenic markers ALP and BMP2 both reduced (P<0.05).On the contrary, the expression of osteogenic markers ALP and BMP2 both increased obviously (P<0.05) as Notch1 signal pathway was inhibited.Conclusion The activated Notch1 signal pathway will inhibit osteogenic differentiation of PDLSCs under dynamic tensile.

Dentin ; Dentin-Bonding Agents ; Plant Extracts

Objective To investigate the expression of HLA-G in lymphocytes,CD3+ T cells,and CD14+ monocytes from patients with rheumatoid arthritis (RA) and their associations with disease activity,disease duration,medication used and clinical parameters.Methods We studied 68 RA patients as well as 63 healthy controls.HLA-G expression was analyzed by flow cytometry in peripheral blood mononuclear cells (PBMCs).Mann Whitney U tests and Spearman rank correlation coefficient test were used for statistical analysis.Results We found that lymphocytes as well as CD3+ T cells,and CD14+ monocytes in RA patients showed a diminished expression of HLA-G compared with healthy controls [1.98％(1.17％-3.66％) vs 2.93％ (1.70％-5.40％),U=1624.5,P＜0.05; 1.35％(0.57％-2.79％) vs 2.16％(1.15％-4.45％),U=1387,P=0.000; 22.65％ (10.59％-36.81％) vs 32.76％ (20.73％-44.62％),U=1526,P＜0.01].Spearman analysis showed that the levels of HLA-G+ lymphocytes as well as CD3+ HLA-G+ T cells was negatively associated with DAS28 score(r=-0.288,P=0.017; r=-0.373,P=0.001),but no significant correlation was detected between the levels of CD14+HLA-G+monocytes and DAS 28 score (P＞0.05).In addition,the levels of expression of HLA-G was not correlated to disease duration,medication used,ESR,CRP,RF,anti-CCP and ANA (P＞0.05).Conclusion Decreased expression of HLA-G are detected in lymphocytes,CD3+ T cells,and CD14+ monocytes from pa-tients with RA,and the abnormality of HLA-G may play an important role in the development of RA.

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