p38-MAPK和STAT3信号分子靶点对微氧化应激下牙髓干细胞增殖、分化的影响

The effects of hypoxic stress on P38-MAPK and STAT3 signal molecular for the proliferation and differentiation of dental pulp stem cells

目的:研究微氧化应激下p38-MAPK信号通路和STAT3信号靶点对牙髓干细胞(DPSCs)增殖和分化的影响。方法:以混合气体(3%O_2,92%N_2,5%CO_2)建立体外微氧培养模型,以常氧(空气,含氧21%)为对照。CCK8法检测细胞增殖,流式细胞术检测细胞周期分布,Western blot检测DPSCs中PCNA表达,茜素红染色检测矿化结节形成,QRT-PCR检测DPSCs中ALP表达情况。结果:常氧组的细胞数量较密集,微氧组的相对数量较少,常氧组DPSCs的增殖明显,而微氧组DPSCs增殖不明显;在不同氧化应激下p38-MAPK通路抑制DPSCs的增殖,STAT3信号分子促进DPSCs的增殖;微氧组和微氧抑制STAT3组的细胞矿化结节较多,ALP表达更高,常氧组和常氧且抑制p38-MAPK组的细胞矿化结节较少,ALP表达更低,微氧组抑制STAT3组的ALP和PCNA相对比值高于其它组。结论:DPSCs在微氧环境下的增殖较差,但分化能力更强,p38-MAPK通路抑制DPSCs的增殖,但对DPSCs分化起到促进作用,STAT3信号分子促进DPSCs的增殖,对DPSCs分化起到抑制作用。

Objective:To study the effects of 38-MAPK pathway under hypoxic stress and the influences of STAT3 signal molecular on the proliferation and differentiation of dental pulp stem cells(DPSCs).Methods:Micro oxidative cultivation model was established in the mixed gas(3%O 2,92%N 2,5%CO 2)in vitro,the control cells were cultured with air(21%O 2).Cell proliferation was examined by CCK8 method and cell cycle distribution by flow cytometry,PCNA expression was detected by Westernblot and mineralized nodule formation by alizarin red staining,ALP expression was detected by QRT-PCR.Results:The DPSCs was dense in oxygen groups,but relatively fewer in hypoxic groups.The proliferation of DPSCs was significantly promoted in oxygen groups,but obvious less in hypoxic groups.p38-MAPK pathway repressed the proliferation of DPSCs under oxidative stress,STAT3 signaling molecules promoted the proliferation of DPSCs.The cells showed more mineralized nodules and higher expression of ALP in hypoxic group,the cells showed less mineralized nodules and lower expression of ALP in normal oxygen groups and normal oxygen with 38-MARK inhibition groups.The relative ratio of ALP and PCNA in STAT3 inhibited hypoxic groups was obviously higher than that of othet groups.Conclusion:DPSCs in hypoxic environment has poor proliferation but stronger differentiation ability.p38-MAPK pathway may inhibite the proliferation,but promote the differentiation of DPSCs,STAT3 signaling molecules may promote the proliferation but inhibite differentiation of DPSCs.