体外成牙环境对牙髓干细胞和外胚间充质干细胞分化的影响

Effects of tooth germ microenvironment in vitro on the differentiation of dental pulp stem cell and ectoblast mesenchyme stem cell

目的利用牙胚细胞(TGC)作为诱导成牙环境,将牙髓干细胞(DPSC)、外胚间充质干细胞(EMSC)分别与其共培养,观察DPSC和EMSC的分化能力。方法利用出生后4 d的大鼠TGC作为诱导成牙环境,将培养的DPSC、EMSC使用BrdU标记及鉴定后与其共培养,免疫荧光双标检测标记细胞表面抗原牙本质涎蛋白(DSP)的表达和碱性磷酸酶(ALP)活性的变化,免疫组化染色鉴定及图像分析DPSC、EMSC在成牙环境中的分化能力。结果共培养7 d后,EMSC共培养组DSP阳性细胞的转化率高于DPSC共培养组(P<0.05)。免疫组化染色图像分析结果表明共培养7 d后,共培养组与TGC单独培养组差异显著(P<0.05)。共培养组3、7 d后ALP活性明显增高,EMSC共培养组较DPSC共培养组ALP活性高。结论混合培养的TGC作为诱导细胞分化的微环境与DPSC、EMSC共培养后,能够诱导细胞向成牙本质细胞分化,EMSC分化能力高于DPSC。

Objective To observe the differential ability of dental pulp stem cell （DPSC） and ectoblast mesenchyme stem cell （EMSC） that were cultured with tooth germ cell （TGC） as the tooth germ microenvironment. Methods The TGC of 4-day old rat was used as the tooth germ microenvironment. The BrdU marked and determined DPSC and EMSC were cultured with the TGC respectively. The expression of cell surface antigen dentin sialoprotein （DSP） and alkaline phosphatase （ALP） activity were determined with double marker immunofluorescence. The differential ability of DPSC and EMSC were determined by the immunohistochemistry and image analysis in the tooth germ microenvi- ronment. Results The transformation efficiency of DSP positive cell in the EMSC co-culture group was higher than that in the DPSC co-culture group（P〈0.05）. The transformation efficiency in the co-cuhure groups was higher than that in the non co-culture group after 7 days by the image analysis of immunohistoehemistry （./）〈0.05）. The ALP activity in the co-culture groups increased after 3 and 7 days. The ALP activity in the EMSC co-culture group was higher than that in the DPSC co-culture group. Conclusion DPSC and EMSC cultured with TGC as the tooth germ microen- vironment can be induced to differentiate into odontoblast. The ability of EMSC is higher than that of DPSC.