LXR inhibits reactive nitrogen species production in cultured microglia. Primary murine microglia were pretreated with the LXR agonist GW3965 (5 μM) with or without RXR agonist fluorobexarotene (0.1 μM) for 1 h then stimulated with LPS (10 ng/ml) or interferon-γ (10 ng/ml) for 48 h. Real-time RT-PCR was used to measure RNA expression (relative expression). Nitrite was measured by Griess assay as an indicator of nitric oxide production. IL-1β and TNF were measured by ELISA. A The effect of GW3965 (GW) or vehicle (VC, 0.05% DMSO) on LPS-induced RNA expression of Nos2, IL1b and Tnf compared to unstimulated (unstim) cells. B The effect of GW3965 (GW) with or without fluorobexarotene (FB) on LPS-induced nitrite, IL-1β and TNF production/release. C The effect of GW3965 (GW) with or without fluorobexarotene (FB) on interferon-γ-induced nitrite and TNF production/release. Data are mean + SD. N = 6 independent experiments, except column A (N = 5). Kruskal-Wallis test: *< 0.05, **< 0.001.