Effect of chromium and cobalt ions on the expression of antioxidant enzymes in human U937 macrophage-like cells.

The main concern associated with metal-on-metal (MM) hip prosthesis is the presence of metal ions, mainly chromium (Cr) and cobalt (Co), which are found both systemically and locally in the organism of patients. Previous studies revealed that Cr(III) and Co(II) ions could induce damages to proteins in macrophage-like cells in vitro, probably through the formation of reactive oxygen species (ROS). We then hypothesized that these ions can modify the expression of antioxidant enzymes in these cells. Results showed that Cr(VI) induced the protein expression of Mn-superoxide dismutase, Cu/Zn-superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase-1 (HO-1) but had no effect of the expression of their mRNA. Cr(III) have no effect on the expression of all these antioxidant enzymes. Co(II) induced the expression of both protein and mRNA of HO-1 only. In conclusion, results showed that Cr(VI), Cr(III), and Co(II) had differential effects on the expression of antioxidant enzymes in macrophage-like cells in vitro. (c) 2010 Wiley Periodicals, Inc.