Toxic Effects of Sodium Arsenite on Liaoning Cashmere Goat Skin Fibroblasts

Liaoning cashmere goats were used as a new arsenic-infected animal model to explore the toxic  effects of sodium arsenite on its skin fibroblasts, providing a theoretical basis for the effects of arsenite on skin fibroblasts of cashmere goats and the mechanism of toxicological action. In the experiment, different concentrations of sodium arsenite (0-120 μmol/L) were used to infect skin fibroblasts of cashmere goats for 24, 48, 72, 96 h, respectively. The effects of sodium arsenite on cell proliferation and inhibition were detected by MTT assay. The changes of cytoskeleton, cytoplasm and organelle were observed by immunofluorescence and TEM (transmission electron microscopy). The comet assay was used to detect DNA damage. FCM (Flow cytometry) was used to detect the changes of cell apoptosis, lysosome and mitochondria. Based on all results, at 24 h and 48 h, the lower concentrations of sodium arsenite (0-5 μmol/L) were found to induce the proliferation of Liaoning cashmere goat skin fibroblasts, while higher concentrations (5-120 μmol/L) inhibited proliferation and could cause cytotoxicity and genotoxicity. Furthermore, at 72 h and 96 h, all concentrations of sodium arsenite always showed inhibitory effects on cell growth. When the treatment time was 24 h, sodium arsenite had shown obvious toxic excitatory effect on cells, so this study chosed 24 h as the best treatment time for sodium arsenite to infect cells. When treated with sodium arsenite (0-5 μmol/L) for 24 h, the cytoskeleton morphology was uniform and microtubule proteins in the cytoskeleton were polymerized; the organelles were complete; the number of living cells and lysosomes increased; as well as MMP (mitochondrial membrane potential) increased. Nevertheless, when the concentration of sodium arsenite was 5-120 μmol/L, there were significant differences in cytoskeleton morphology, and the microtubule protein fluorescence was significantly weakened; the number of organelle damage, DNA damage and apoptosis significantly increased; lysosomal activity and MMP (ΔΨm) were decreased. These results indicate that the mechanism of apoptosis induced by sodium arsenite may be associated with lysosomal and mitochondrial pathways. This study concludes that sodium arsenite on the toxic effects of cashmere goat skin cells show “dose-time-effect” relationship, that is, at 24 h, low concentrations of sodium arsenite can promote cell proliferation, and the optimal concentration for cell growth is 0.5 μmol/L. However, sodium arsenite (>5 μmol/L) can cause the cytotoxicity and genotoxicity.