Department of Biology, Faculty of Sciences, Arak University, Arak, Iran.
Cell J. 2012 Fall;14(3):161-70. Epub 2012 Dec 12.
Although arsenite is toxic it is currently recommended for the treatment of malignancies. In this study the effects of sub-micromolar concentrations of sodium arsenite on the viability, morphology and mechanism of cell death of rat bone marrow mesenchymal stem cells (BMCs) over 21 days was investigated.
In this experimental study, BMCs were extracted in Dulbecco's Modified Eagles Medium (DMEM) containing 15% of fetal bovine serum (FBS) and expanded till the 3(rd) passage. The cells were treated with 1, 10, 25, 50, 75 and 100 nM of sodium arsenite for 21 days and the viability of the cells estimated using 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium (MTT) and trypan blue staining. Cells were then treated with the selected dose (25 nM) of sodium arsenite to determine their colony forming ability (CFA) and population doubling number (PDN). Morphology of the cells was studied using florescent dyes, and the integrity of the DNA was investigated using the comet assay and agarose gel electrophoresis. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the caspase 3 assay were then applied to understand the mechanism of cell death. Data was analyzed using one way ANOVA, Tukey test.
A significant reduction of viability, PDN and CFA was found following treatment of BMCs with 25 nM sodium arsenite (p<0.05). Cytoplasm shrinkage and a significant decrease in the diameter of the nuclei were also seen. Comet assay and agarose gel electrophoresis revealed DNA breakage, while positive TUNEL and activated caspase 3 confirmed the apoptosis.
A low concentration of sodium arsenite (25 nM) caused reduction of viability due to induction of apoptosis. Therefore, long term exposure to low dose of this chemical may have unwanted effects on BMCs.
尽管亚砷酸钠具有毒性，但目前仍推荐将其用于治疗恶性肿瘤。本研究旨在探讨亚砷酸钠在低于微摩尔浓度下对大鼠骨髓间充质干细胞（BMCs）活力、形态和细胞死亡机制的影响，为期 21 天。
在这项实验研究中，将 BMCs 在含有 15%胎牛血清（FBS）的 DMEM 中提取并扩增至第 3 代。将细胞用 1、10、25、50、75 和 100 nM 亚砷酸钠处理 21 天，并用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑（MTT）和台盼蓝染色法估计细胞活力。然后用选定剂量（25 nM）的亚砷酸钠处理细胞，以确定其集落形成能力（CFA）和群体倍增数（PDN）。用荧光染料研究细胞形态，用彗星试验和琼脂糖凝胶电泳研究 DNA 完整性。然后应用末端脱氧核苷酸转移酶 dUTP 缺口末端标记（TUNEL）和 caspase 3 测定法来了解细胞死亡的机制。采用单因素方差分析和 Tukey 检验进行数据分析。
用 25 nM 亚砷酸钠处理 BMCs 后，发现细胞活力、PDN 和 CFA 显著降低（p<0.05）。细胞质收缩和细胞核直径显著减小。彗星试验和琼脂糖凝胶电泳显示 DNA 断裂，而阳性 TUNEL 和激活的 caspase 3 证实了细胞凋亡。
低浓度的亚砷酸钠（25 nM）通过诱导细胞凋亡导致细胞活力降低。因此，长期暴露于这种化学物质的低剂量可能会对 BMCs 产生不良影响。
