牙本质细胞外基质蛋白对乳牙牙髓干细胞体外增殖、分化能力的影响

目的:提取牙本质细胞外基质蛋白(Dentinextracellularmatrixproteins,DEMPs)研究其对人脱落的乳牙牙髓干细胞(Stemcellfromhumanexfoliateddeciduousteeth,SHED)体外增殖分化能力的影响。方法:采用组织块联合酶消化法获得SHED并进行体外培养。成骨诱导液诱导细胞,鉴定其多向分化能力;拔取健康牛牙,用4mol/L盐酸胍和0.5mol/LEDTA提取DEMPs,四唑盐比色法(MTT)检测不同浓度DEMPs对SHED增殖能力的影响,同时测定DEMPs对SHED碱性磷酸酶(ALP)活性的影响;实时荧光定量PCR(RT-PCR)检测牙本质磷蛋白与牙本质基质蛋白1的mRNA表达情况。结果:DEMPs诱导细胞培养3d、5d可促进细胞增殖。细胞培养5、7d上调ALP活性,RT-PCR结果显示,DEMPs诱导后可促进DSPP与DMP-1基因的表达。结论:牙本质细胞外基质蛋白可以促进SHED的增殖与牙向分化能力。

Effect of DEMPs on Proliferation and Differentiation of SHED in Vitro.

Objective: To investigate the effect of DEMPs on proliferation and differentiation of SHED in vitro and to provide theoretical basis for the application of DEMPs in tooth reparation and regeneration. Methods: The stem cells were collected from human exfoliated deciduous teeth by enzyme digestion and tissue ex-plant method. We assessed the multi-differentiation potentials of the cells by inducement. Healthy teeth wereextracted from cattles, and prepared dentine matrix of the teeth was extracted by 4mol/L guanidine hydrochloride and 0.5mol/L EDTA. The effect of DEMPs on the proliferation activity of SHED was evaluated by MTT method and the effect ofDEMPs on the activity of ALP was also examined. The expression of DMP-1 and DSPPinduced by DEMPs observed by RT-PCR. Results: The proliferation of SHED was induced by DEMPs after three and five days, and increased activity of ALP was induced by DEMPs after five and seven days. The mRNA expression of DSPP and DMP-1 in SHED induced by DEMPs. Conclusion: DEMPs can promote the proliferation and the odontogenic differentiation of SHED.