Inhibition of NADPH oxidase and gene deletion of gp91phox modulates microglial activation phenotypes. (a–d) Quantitative real-time PCR analysis showing expression of Ym1, MARCO, TNF-α, and CCL2 mRNA (relative to Pgk1) in WT mice pre-treated with apocynin. (e–h) The Ym1, MARCO, TNF-α, and CCR2 mRNA expression (relative to Pgk1) in WT and gp91phox−/− mice was measured by quantitative PCR. RNA samples were prepared from brains of WT and p47phox−/− mice at 24 h after LPS. Mean ± SEM (n = 5), *p < 0.05, **p < 0.01.