Hydrogen peroxide enhances LPS-induced nitric oxide production via the expression of interferon beta in BV-2 microglial cells

Activated microglia produces inflammatory cytokines and nitric oxide (NO) that involved in neuronal injury and neurodegenerative diseases. We report herein, that H2O2 intensifies the LPS-triggered expression of iNOS in the microglia cell line, BV-2, resulting in an enhancement in the production of NO. The NO production induced by a combination of LPS and H2O2 was blocked by the addition of an anti-interferonβ (IFNβ) neutral antibody, suggesting that IFNβ levels are correlated with the LPS/H2O2-induced production of NO. However, although the expression of IFNβ was induced by H2O2 treatment alone, neither the expression of iNOS mRNA nor the production of NO were induced. In addition, the expression of IFN receptor (IFNR) was induced by LPS but not by H2O2. These data indicate that although H2O2 alone cannot induce iNOS expression because of the insufficient expression of IFNR, in the presence of LPS, H2O2 enhances iNOS expression via the expression of IFNβ. Our findings suggest that H2O2 produced by activated microglia further enhances NO production in various inflammatory states.

► H2O2 enhanced the LPS-induced NO production and iNOS expression in BV-2 cells.
► The expression of IFNβ by LPS and H2O2 was account for the NO production.
► LPS induced the IFN receptor expression.
► H2O2 and NO induced the IFNβ mRNA expression.