低剂量辐射对人骨髓间充质干细胞影响的研究

目的 探讨低剂量辐射(LDR)对人骨髓间充质干细胞(hBM-MSC)生物学特性的影响。方法 应用体外培养传代的第四代hBM-MSC,采用X射线照射,照射剂量分别为50 mGy、75mGy、100 mGv,剂量率为12.5 mGy/min,分别观察LDR后hBM-MSC生长曲线、细胞周期与凋亡的变化及细胞因子、干细胞因子(SCF)、白细胞介素6(IL-6)、巨噬细胞集落刺激因子(M-CSF)表达量的变化。结果 LDR后,hBM-MSC从72 h起生长明显加快;LDR照射hBM-MSC后,在G0-G1期百分率逐渐减少,S期百分率在照射后48 h、72 h逐渐明显增多,以75 mGy照射后72 h的S期百分率增多最明显,为68.88%,而细胞凋亡的变化结果是LDR后在24 h、48 h有增多趋势,照射后72 h,凋亡细胞百分率有减少趋势;LDR照射hBM。MSC后24 h、48 h SCF分泌量均有升高趋势;50mGv、75mgy、100mGyX射线照射hBM-MSC后在培养的24 h、48 h,IL-6分泌量均有升高趋势;LDR照射hBM-MSC后,除50mGy照射后72h外,M-CSF分泌量在不同剂量照射后24 h、48 h、72 h均持续升高。结论 LDR后hBM-MSC从生长曲线、细胞周期与凋亡的变化及细胞因子表达量的变化均表现出兴奋性效应。

Study on human mesenchymal stem cells from bone marrow pretreated with low dose radiation

Objective To study effects of human bone marrow mesenchymal stem ceHs(hBM-MSC)from bone marrow pretreated with low dose radiation(LDR).Methods The ceils were the hBM-MSC.They were exposed to X rays at the dose of 50 mGy,75 mGy、100 mGy(dose rate 12.5 mGy/min).The growth curve,cell cycle and apoptosis of hBM-MSC treated by LDR were investigated.The content changes of stem cell factor(SCF),interleukin-6(IL-6),macrophage colony stimulating factor(M-CSF)secreted by hBM-MSC after treated by LDR were determined by enzyme linked immunosorbont assay method.Results The growth rates of hBM-MSC treated by LDR obviously increase from 72 h.The cell cycle and apoptosis were examined with FORTRAN Atomatic Checkout Systom.The results show that the G0/G1 stage cells decrease after exposure to LDR,the percent of G0/G1 stage cells of 75 mGy at 72 h is the lowest(30.86%).However,the S stage cells percentage gradually increase at 48 h and 72 h.The most one is 75 mGy group at 72 h,which reaches to 68.88%.The apoptosis percentages have increased tendency at 24 h and 48h in all dose groups,especially in 100 mGy at 24 h(25.99%),while have decreased tendency at 72 h and the most decreased group is the 50 mGy(6.8%),transient enhancement of apoptosis ha the early stage and soon being decreased.The contents of SCF have increased tendency at 24 h,48 h.As for IL-6,the contents in different dose groups at 24 h and 48 h have up-regulation.These groups,50 mGy at 24 h,48 h,75 mGy at 24 h,48 h,100 mGy at 24 h have statistical difference compared with their control groups respectively.The content of IL-6 has greatest enhancement at dose of50 mGy.The contents of M-SCF in all the groups at 24 h,48 h and 72 h except for the 50 mGy dose at 72 h have also been found increased.The greatest increased content occur in the 75 mGy dose group at 72 h.Conclusion This conclusion show that LDR has hormesis effect on hBM-MSC in cell growth,cell cycle and content of hematopoietic factors.