Cadmium affects viability of bone marrow mesenchymal stem cells through membrane impairment, intracellular calcium elevation and DNA breakage.

ABSTRACT

Background: Cadmium is an important heavy metal with occupational and environmental hazard. Cadmium toxicity results mainly in bone-related complication such as itai-itai disease. Mesenchymal stem cells of the bone marrow have the ability to differentiate to osteoblasts which ensure the well-being of the bone tissue. Thus the aim was to investigate the effect of cadmium on viability of rat bone marrow mesenchymal stem cells. Materials and Methods: The rat bone marrow mesenchymal stem cells were grown to confluency in DMEM medium supplemented with 15% fetal bovine serum and penicillin-streptomycin up to third passage. Then the cells were treated with 0, 5, 15, 25, 35, and 45 of CdCl 2 at 12, 24, 36, and 48 h, and their viability was investigated using trypan blue staining. In addition, after treatment with selected dose (15 and 45 μM) and time (24 and 48 h) the cell morphology, DNA damage and calcium content of the cells were evaluated. Data was analyzed using one and two-way ANOVA (Tukey test) and the P<0.05 was taken as the level of significant. Results: Cadmium chloride caused significant dose and time-dependent reduction of viability. In addition, morphological changes such as nuclear breakage and chromatin condensation, as well as cytoplasm shrinkage, were observed. The Comet assay showed a significant dose-dependent increase in DNA damage and also a significant increase in the intracellular levels of Ca 2+ was observed. Conclusion: Cadmium chloride is a toxic compound which might affect the well-being of bone tissue through affecting the mesenchymal stem cells.