Induction of copper/zinc‐superoxide dismutase by CCL5/CCR5 activation causes tumour necrosis factor‐α and reactive oxygen species production in macrophages

Using two-dimensional sodium dodecyl sulphate–polyacrylamide gel electrophoresis, we found that copper/zinc superoxide dismutase (Cu/Zn-SOD, SOD-1) was induced in constructed CCR5 stably transfected HEK 293 cells, but not in mock cells, treated with CCL5. CCL5-induced SOD-1 expression was also confirmed in HEK 293-CCR5 cells and CCR5-positive granulocyte–macrophage colony-stimulating factor-induced human macrophages and murine macrophage RAW264.7 cells. CCL5 and CCR5 interaction induced SOD-1 expression mainly via MEK–ERK activation. In addition, we provided evidence that upregulation of SOD-1 by CCL5/CCR5 activation occurred in parallel with the increased release of tumour necrosis factor-α and nitric oxide and production of intracellular reactive oxygen species as well as enhanced nuclear factor-κB transcriptional activity in CCR5-positive RAW264.7 cells. Conversely, the MEK1/2 inhibitor PD98059 significantly inhibited SOD-1 expression with the decrease of these biological responses. More importantly, inhibition of SOD-1 activity by disulfiram also strongly inhibited the CCL5-induced biological effects. These data suggest that SOD-1 mediates CCR5 activation by CCL5 and that pharmacological modulation of SOD-1 may be beneficial to CCR5-associated diseases.