Inducing Arsenic -resistance Cells With Human Bone Marrow-derived Mesenchymal Stem Cells

Objective : To select the suitable cells ,we explored the difference of biological characteristics among the fetal, adult and old mesenchymal stem cells(MSCs) derived from bone marrow. To obtain stable arsenic-resistance cells, the fetal MSCs were exposed to low-level arsenite for 18 weeks. Methods: Cells from 6 months fetal, adult and old bone marrow were cultured in α-MEM medium to obtain MSCs. The growth curve , the adherent ability and the toxicity of NaAsO₂ were investigated. After 24h cytotoxicity test of the fetal MSCs, we chosed lumol/L NaAsO₂ to be the dose under which the cell death-rate was 5%-10% .The fetal MSCs were exposed to low-level arsenite. MTT was used to detect the survival rate and IC50 of arsenic-exposed cells and the control cells, which can reflect the change of arsenic tolerance. A hydride generation—atomic fluorescence spectrometry method was used to detect arsenic in the arsenic-resistance cells and the control cells. In order to study the mechanism of arsenic-resistance, we also examined the intracellular GSH and GST content in the arsenic-resistance cells and the control cells. Results: The fetal, adult and old MSCs were similar in cell morphology.The proliferation of the MSCs from the fetus was higher than that from the adult and the old . The fetal MSCs were continuously exposed to lumol/L NaAsO₂. Parallel cells were cultured in medium without arsenic provided passage-matched control. After the fetal MSCs were continuously exposed to low level NaAsO₂ for 18 weeks, cells exhibited dramatic resistance to acute arsenite toxicity. Compared to control cells, arsenic-resistance cells showed reduction in arsenic accumulation in cells. The GSH levels and GST activity of arsenic-resistance cells were higher than that of control cells.Clonclusion: The fetal MSCs had a big ability of proliferation. Acquisition of stable arsenic-resistance in MSCs was available by using cell culture and adding low-level arsenic. Our research established a solid basis for further study about the mechanisms of arsenic-resistance in human being.