[Effects of Wnt3a on osteogenic differentiation of dental pulp stem cells].

Objective: To investigate the effect of Wnt3a on osteogenic differentiation of human dental pulp stem cells (DPSC). Methods: DPSCs were subjected to different concentrations of Wnt3a (0, 5, 20, 50 and 100 μg/L) and at seven days after culture the alkaline phosphatase (ALP) activity was tested. Mineralized nodule formation was examined by alizarin red staining. Osteogenic-related gene expression of bone sialoprotein (BSP), osteocalcin (OCN), collagen type Ⅰ (COL-Ⅰ), Runt-related transcription factor-2 (RUNX2) was examined by quantitative real-time PCR (qPCR). Results: After seven days of induction by DPSC, Wnt3a protein could inhibit the ALP activity (concentration 0: 1.076±0.203, 5 μg/L: 0.828±0.118, 20 μg/L: 0.505±0.044, 50 μg/L: 0.499±0.038, 100 μg/L: 0.483±0.060). The expression of OCN in 5 μg/L Wnt3a group (0.092±0.005) was lower than that in culture medium (0.858±0.190)(P<0.05). Alizarin red staining showed that 5 μg/L Wnt3a had no mineralization induction effect on DPSC. Conclusions: Wnt3a could inhibit osteogenic differentiation of dental pulp stem cells.目的： 探讨Wnt3a蛋白对牙髓干细胞（dental pulp stem cells，DPSC）成骨向分化的影响，进一步说明Wnt信号通路在DPSC分化中的作用。 方法： 将不同质量浓度[0（培养液组）、5、20、50及100 μg/L]的Wnt3a蛋白作用于DPSC，于诱导培养的第7天检测其碱性磷酸酶（alkaline phosphatase，ALP）活性，对检测结果进行单因素方差分析；茜素红染色检测矿化结节形成情况；通过实时荧光定量PCR（quantitative real-time PCR，qPCR）检测骨涎蛋白、Ⅰ型胶原、Runt相关转录因子2（Runt-related transcription factor-2，RUNX2）及骨钙蛋白4种骨源性基因的表达，对结果数据采用独立样本t检验进行统计学分析。 结果： DPSC诱导7 d后检测结果显示，Wnt3a蛋白可抑制ALP的活性，0、5、20、50及100 μg/L组ALP的活性分别为1.076±0.203、0.828±0.118、0.505±0.044、0.499±0.038及0.483±0.060，Wnt3a蛋白质量浓度越高对ALP活性的抑制作用越强；qPCR检测显示，5 μg/L Wnt3a蛋白组骨钙蛋白基因阳性表达水平（0.092±0.005）显著低于培养液组（0.858±0.190）（P<0.05）；28 d后茜素红染色结果显示，5 μg/L Wnt3a蛋白对DPSC无明显的诱导矿化现象。 结论： Wnt3a蛋白可抑制DPSC成骨向分化。.