ABSTRACT
OBJECTIVES: Bone marrow mesenchymal stem cells (MSCs) play an important role in bone health. Cadmium causes osteoporosis, but the exact mechanisms of its effect on MSCs are not known. MATERIALS AND METHODS: Rats were treated with cadmium chloride (40 mg/l) in drinking water for six weeks, and then the biochemical and morphological studies on MSCs were carried out as a cellular backup for osteoblasts. Viability and proliferation properties of the cells were evaluated using MTT assay, trypan blue, population doubling number, and colony forming assay. Morphology of the cells and biochemical parameters including activity of metabolic (ALP, AST, and ALT) and antioxidant enzymes (SOD, CAT, and POX) as well as the MDA level (as an indication of lipid peroxidation) were investigated. In addition, intracellular calcium, potassium, and sodium content were estimated. Data was analyzed statistically and P<0.05 was taken as the level of significance. RESULTS: The results showed a significant reduction in viability and proliferation ability of extracted cells when compared to the controls. In addition, it was revealed that the cadmium treatment of rats caused a significant reduction in nuclear diameter and cytoplasm area. Also, there was significant increase in (ALT) and (AST) activity and intracellular calcium and potassium content but no change was observed with sodium content and ALP activity. The results showed [a] significant reduction in the antioxidant enzyme activity and increases in the MDA level. CONCLUSION: Based on the present study, reduction of viability and proliferation ability of MSCs might be a causative factor of osteoporosis in industrial areas.
ABSTRACT
OBJECTIVE(S): Arsenic compounds are potent human carcinogen and produce a variety of stress responses in mammalian cells. Recently sodium arsenite has been recommended to be used as anti malignancy drug by American food and drug administration (FDA). In this study, we aimed to determine the apoptosis inducing effect of sodium arsenite on rat bone marrow mesenchymal stem cells exposed in vitro. METHODOLOGY: Cell morphology was studied with the help of Hoechst and propidium iodide as well as with single cell gel electrophoresis(comet assay), TUNEL assay and caspase activity base on immunocytochemistry using commercial kit were considered to study the mechanism of cell death. RESULTS: Our result showed that the sodium arsenite with concentration of 0.1 µM in 36 hr induces caspase dependent apoptosis in rat bone marrow mesenchymal stem cells. This concentration is the lowest level of sodium arsenite to be reported with apoptosis induction ability in stem cells. CONCLUSION: Since sodium arsenite is used in therapy, more research should be carried out on the effect of this chemical on stem cells, especially MSCs.
ABSTRACT
OBJECTIVES: Para-Nonylphenol (p-NP) is used in many industries and our previous study showed that p-NP causes a reduction in rats bone marrow mesenchymal stem cells (MSCs) viability. The aim of this study was to investigate the effect of p-NP on osteogenic differentiation of MSCs. MATERIALS AND METHODS: MSCs were isolated and expanded to 3rd passage, then cultured in DMEM supplemented with osteogenic media as well as 0.5 or 2.5 µM of p-NP. After 5, 10, 15, and 21 days, the viability and the level of mineralization was determined using MTT assay and alizarin red, respectively. In addition, morphology and nuclear diameter of the cells were studied with the help of fluorescent dye. Furthermore, calcium content and alkalinphosphatase activity were also estimated using commercial kits. Data were statistically analyzed and the P<0.05 was taken as the level of significance. RESULTS: The viability and mineralization of the cells treated with 2.5 µM of p-NP reduced significantly after day 10 in comparison with the control group and administration of 0.5 µM. Moreover, chromatin condensation, reduction of nuclei diameter, and cytoplasm shrinkage was observed in the cell treated with 2.5 µM. The calcium concentration and alkalinphosphatase activity of the cells decreased significantly with 2.5 µM of p-NP when compared with 0.5 µM and control group. CONCLUSION: Adverse effect of p-NP was observed on osteogenic differentiation of MSCs at 2.5 µM due to disruption of mineralization. We strongly suggest more investigations on this chemical with respect to other stem cells, especially skin stem cells as p-NP is used in the formulation of cosmetics.
