活性氧介导铁过载对正常及辐射损伤小鼠骨髓间充质干细胞的影响

The effect of iron overload on normal and irradiational injured bone marrow-derived murine mesenchymal stem cells in vivo

目的探讨铁过载对正常及病态骨髓间充质干细胞(MSCs)的损伤作用及其机制。方法将40只雄性C57BL/6小鼠随机分为对照组、铁剂组、照射组、及照射加铁剂组,给予铁剂4周。分离培养MSCs,普鲁士蓝铁染色检测MSCs内铁颗粒、流式细胞仪检测可变铁池(LIP)及活性氧(ROS)水平,CCK8检测MSCs增殖能力,油红-O染色检测MSCs成脂定向分化能力、茜素红染色检测成骨定向分化能力,实时定量-PCR(real-time PCR)检测成骨相关基因表达。结果与对照组及照射组相比,铁剂组及照射加铁剂组MSCs内明显存在铁颗粒,LIP水平明显增高(P<0.05);ROS水平明显增加(P<0.05);细胞增殖能力明显下降(P<0.05);成骨分化能力下降(P<0.05),向成脂细胞分化能力增强。结论铁过载可介导ROS升高影响正常及病态骨髓MSCs的增殖、定向分化能力,降低其造血支持作用,并间接引起骨损害。

Objective To establish both normal and irradiational injured（IR） bone marrow mesenchymal stem cells （MSCs） iron overload models, explore the effects of iron overload on routine bone marrow MSCs and the possible mechanism in this process. Methods Forty male mice（C57BL/6） were randomly divided into four groups：control, iron overload, IR and IR with iron treated groups, Iron dextran was intraperitoneally injected （i. p. ） at 25 mg/mL every 3 day to establish the iron overload model, while control and IR group received saline for 4 weeks. Isolation and culture of mesenchymal stem cells from mouse compact bone. The level of labile iron pool （LIP） and reactive oxygen species （ROS） were measured to define oxidative stress state. Cell prolifiration was measured through population double time （DT） and cck8 assay. The osteoblastic differentiation ability was assessed by Alkaline phosphatase （ALP） activity, alizarin red stain and the osteogenic gene expression. Results Compared with control and IR groups, iron deposite increased significently in Fe and IR ＋ Fe groups, The LIP level of MSCs was also increased by iron dextran treatment（ P 〈 0. 05 ）. The level of intracellular ROS with two iron overload groups was higher than that of the control and IR groups. The prolifiration of Fe and IR ＋ Fe groups was less than control and IR group （ P 〈 0. 05 ）. The osteoblastic differentation ability of experimental group was supressed by ROS-induced iron overload induced. Conclusions Iron overload may inhibit the proliferation and differentation of normal and IR injured bone marrow MSCs by enhancing the generation of ROS.