Figure 3.

Effect of age and inflammation on NO and ROS production induced by LPS in adult microglial cells in culture. A. Cell identity and purity of microglial cell cultures derived from 2 and 12 months old mice were assessed by immunofluorescence against GFP in glial cultures obtained from Mafia transgenic mice expressing EGFP under the specific c-fms promoter. Arrowheads show elongated cells, characteristic of surveillance microglia, whereas arrows show round shaped cell bodies consistent with an activated phenotype. Bar = 50 μm. Young and adult mice received a single i.p. injection of vehicle (PBS) or LPS (0.5 mg/Kg animal). Microglia cultures were established 48 h post injection, and production of B) NO and C) ROS induced by LPS were evaluated by the Griess assay and NBT assay, respectively, after cultures were exposed or not to 1 μg / mL LPS for 48 h. Data correspond to the mean ± SEM of 5 independent experiments in duplicate, * P <0.05, ** P <0.01, ANOVA with Tukey's post hoc). Whereas basal levels of NO and ROS were similar at both ages, inflammatory activation of cultures predominantly induced NO production in young animals and ROS production in microglia obtained from aged mice.