碱性成纤维细胞生长因子通过激活Wnt/β-Catenin信号通路促进根尖牙乳头干细胞的增殖

Basic fibroblast growth factor promotes the proliferation of stem cells from the apical papilla through activation of Wnt/β-Catenin signaling pathway

背景:碱性成纤维细胞因子作用于成纤维细胞时,可以通过激活Wnt信号诱导其增殖,但在其作用于根尖牙乳头干细胞的研究中,是否也可以激活Wnt/β-Catenin信号通路,以及激活该通路后对根尖牙乳头干细胞的生物学活动有何影响尚不清楚。目的:探讨碱性成纤维细胞因子对根尖牙乳头干细胞增殖的调控作用。方法:通过酶消化法和有限稀释法克隆化培养人根尖牙乳头干细胞;以15μg/L碱性成纤维细胞因子作用根尖牙乳头干细胞2 d,采用RT-PCR、Western blot检测β-Catenin、TCF1、TCF3、LEF1 mRNA与蛋白的表达。然后进一步研究在Wnt/β-Catenin信号通路抑制的情况下碱性成纤维细胞因子对根尖牙乳头干细胞增殖的影响,设置碱性成纤维细胞因子(15μg/L)+Dkk-1组、碱性成纤维细胞因子(15μg/L)组和阴性对照组,采用MTT比色法和EdU法对比各组根尖牙乳头干细胞增殖情况。结果与结论:①15μg/L碱性成纤维细胞因子作用后上调了根尖牙乳头干细胞中β-Catenin、TCF1、TCF3、LEF1 mRNA和蛋白的表达(P<0.05);②碱性成纤维细胞因子(15μg/L)组根尖牙乳头干细胞增殖能力强于碱性成纤维细胞因子(15μg/L)+Dkk-1组和阴性对照组(P<0.05);③结果表明,碱性成纤维细胞因子作用根尖牙乳头干细胞后能促进Wnt/β-Catenin信号通路关键分子β-Catenin及下游分子TCF1、TCF3、LEF1的表达,Wnt/β-Catenin信号通路参与碱性成纤维细胞因子调控根尖牙乳头干细胞增殖的过程。

BACKGROUND:When basic fibroblast factors act on fibroblasts,they can induce their proliferation by activating Wnt signaling.However,in the study of its effect on apical dental papilla stem cells,whether it can activate the Wnt/β-Catenin signaling pathway and the effect of activating this pathway on the biological activities of apical dental papilla stem cells remains unclear.OBJECTIVE:To investigate the regulatory role of basic fibroblast growth factor on the proliferation of stem cells from apical papilla.METHODS:Human stem cells from apical papilla were cloned and cultured through enzymatic digestion and limiting dilution assay,and then treated with 15μg/L basic fibroblast growth factor for 2 days.RT-PCR and western blot assay were used to detect the expression ofβ-Catenin,TCF1,TCF3,and LEF1 mRNAs and proteins.The effect of basic fibroblast growth factor on the proliferation of stem cells from apical papilla was further studied in the case of Wnt/β-Catenin signaling pathway inhibition.The basic fibroblast growth factor(15μg/L)+Dkk-1 group,basic fibroblast growth factor(15μg/L)group,and negative control group were set.The proliferation of stem cells from apical papilla in each group was compared by MTT assay and EdU assay.RESULTS AND CONCLUSION:(1)The expression levels ofβ-Catenin,TCF1,TCF3,and LEF1 mRNAs and proteins were upregulated by 15μg/L basic fibroblast growth factor on stem cells from apical papilla(P<0.05).(2)The stem cells from apical papilla of the basic fibroblast growth factor(15μg/L)group showed stronger proliferation activity than that in the negative control group and basic fibroblast growth factor(15μg/L)+Dkk-1 group(P<0.05).(3)Results suggest that basic fibroblast growth factor can promote the expression of key moleculesβ-Catenin in Wnt/β-Catenin signaling pathway and downstream molecules TCF1,TCF3,and LEF1.Wnt/β-Catenin signaling pathway participates in the regulation of basic fibroblast growth factor on the proliferation of stem cells from apical papilla.