The protective effects of simvastatin in Cadmium-Induced preosteoblast injury through Nox4

Cadmium (Cd) has a direct toxic effect on bones. Statins such as simvastatin have protective effects on various diseases, including on tissue injury. The current study revealed the efficacy of simvastatin on Cd-induced preosteoblast injury. Preosteoblast MC3T3-E1 cells were incubated with various doses of CdCl2 for 12 h, 24 h and 48 h, and then the cell cytotoxicity was assessed using MTT assay and flow cytometry, respectively. The expression level of Nox4 was assessed by Western blot and qRT-PCR. The morphological appearance of MC3T3-E1 cells was observed under a microscope. Cells exposed to CdCl2 (5 µM) were further treated by simvastatin at various doses, subsequently cell viability, apoptosis and the expression of Nox4 were measured. Furthermore, to confirm the protective effects of simvastatin on Cd-induced pre-osteoblast injury, functional rescue assays were performed after corresponding cell treatment by simvastatin (10-8 M), CdCl2 (5 µM), and overexpression of Nox4. Expressions of cell apoptosis-related markers were measured by Western blot and qRT-PCR. The results revealed that CdCl2 caused MC3T3-E1 cell injury because the cell viability was decreased and the apoptosis was increased. Nox4 expression was up-regulated with the increase of CdCl2 concentrations. Simvastatin increased the cell viability, relieved the cell apoptosis and Nox4 expression previously increased by CdCl2. The effects of CdCl2 on MC3T3-E1 cells and Nox4 expression could be attenuated by simvastatin, and promoted by Nox4 overexpression. The current study found that simvastatin protects Cd-induced preosteoblast injury via Nox4, thus, it can be used as a potential drug for treating cadmium-induced bone injury.