无机砷暴露对人脐带间充质干细胞的增殖及分化的影响

目的 探究无机砷(iAs)暴露对人脐带间充质干细胞的增殖及分化的影响，为iAs的发育毒性研究提供实验依据。方法 以具有多向分化潜能的人脐带间充质干细胞(hUCMSCs)为细胞模型，用不同浓度的亚砷酸盐(NaAsO₂)染毒hUCMSCs 24 h,检测细胞活力；用5μmol/L的NaAsO₂染毒hUCMSCs 24 h,做细胞生长情况检测、多能性标志蛋白CD45、CD105及多能性标志基因Oct4、Nanog的检测，彗星实验检测DNA损伤情况、细胞分化实验检测；染毒后hUCMSCs的向成脂、成骨和成软骨分化及其特异性基因PPARγ、ALP、COMP表达量的检测。采用独立样本t检验进行两组间均数差异的比较，采用单因素方差分析进行多组间均数的比较。结果 随着NaAsO₂浓度的升高，hUCMSCs存活率逐渐降低(F=13.650,P<0.001);5μmol/L的NaAsO₂染毒hUCMSCs,对其细胞增殖的没有显著影响(t=0.507,P=0.615);多能性标志蛋白CD45、CD105仍有表达，多...

Effects of inorganic arsenic exposure on the proliferating and differentiation of human umbilical cord mesenchymal stem cell

Objective To investigate the effects of inorganic arsenic(iAs)exposure on the proliferation and differentiation of human umbilical cord mesenchymal stem cells, and to provide experimental evidence for the study of developmental toxicity of iAs. Methods Human umbilical cord mesenchymal stem cells(hUCMSCs)with multidirectional differentiation potential were treated with different concentrations of NaAsO₂ for 24h to detect cell viability. HUCMSCs were exposed to 5 μmol/L NaAsO₂ for 24 h. The cell growth detection test, pluripotency marker proteins CD45 and CD105 detection test, pluripotency marker genes Oct4 and Nanog detection test were carried out, and DNA damage were detected by comet assay. Adipogenic, osteogenic and chondrogenic differentiation of hUCMSCs after exposure and the expression of specific genes PPARγ, ALP and COMP were detected. Independent sample t-test was used to compare the mean difference between the two groups, and one-way analysis of variance was used to compare the mean difference between the multiple groups. Results With the increase of NaAsO₂ concentration, the survival rate of hUCMSCs decreased gradually(F=13.650, P<0.001). 5 μmol/L NaAsO₂ exposure to hUCMSCs had no significant effect on cell proliferation(t=0.507, P=0.615), but the expression of pluripotency marker proteins CD45 and CD105 was still observed, and the expression of pluripotency marker genes Oct4 and Nanog significantly decreased(t=3.442, P=0.013; t=4.389, P<0.009), which resulted in the decrease of cell pluripotency. Comet assay showed that the DNA damage of hUCMSCs was enhanced after exposure(t=6.614, P=0.003). Cell differentiation assay showed that the adipogenic, osteogenic and chondrogenic differentiation rates of hUCMSCs decreased, and the expressions of corresponding specific genes PPARγ, ALP and COMP significantly decreased(t=15.390, P<0.001; t=31.854, P<0.001; t=11.050, P<0.001), indicating abnormal cell differentiation. Conclusion With the increase of iAs exposure concentration, the proliferation ability of hUCMSCs decreases. Even the low concentration of iAs exposure will affect the differentiation function of hUCMSCs, leading to abnormal differentiation.