Glutamate Receptors Editing Figure 9. KA-induced editing of AMPA editing site glutamate receptor subunits in the hippocampus of COX-2+/+ and COX-22/2 mice. Evaluation of RNA editing levels of the AMPA glutamate receptors in the hippocampus of mice injected with KA. (A) GluR3 R/G site flip- flop- variant and (B) GluR4 R/G flip- flop-variant, editing site. Data are presented as mean 6 SEM (n = 6). Statistical analysis was performed with Student’s t test (*P,0.05, **P,0.01, ***P,0.001). doi:10.1371/journal.pone.0019398.g009 mRNA expression of genes involved in the neuroinflammatory response is increased in COX-22/2 mice after KA Gene expression of cytokines was determined using real time PCR in hippocampus and cortex. In the hippocampus, no changes were observed in the mRNA expression of all inflammatory markers analyzed when we compared vehicle-injected COX-22/2 with vehicle-injected WT mice (Fig. 11A–C). These data indicate that COX-2 deletion per se does not alter the transcription rate of inflammatory markers. KA-injection significantly increased the expression of TNF-a, IL-1b and IL-6 in both COX-22/2 and WT mice, however, the increase was significantly higher in the COX- 22/2 mice (P,0.001; Fig. 11A–C). In the cortex, no changes was observed in the mRNA expression of TNF-a, IL-1b and IL-6 genes when we compared vehicle-injected COX-22/2 with vehicle-injected WT mice (Fig. 12A–C). KA-injection increased the expression of TNF-a (3.0560.41, p,0.001), IL-1b (1.4860.09, p,0.01) and IL-6 genes (1.8360.39, p,0.01) in COX-22/2 mice and the expression of TNF-a (1.8960.17, p,0.05) in WT mice (Fig. 12A–C). The increase in the gene expression of TNF-a was significantly higher in KA-injected COX-22/2 than in KA-injected WT mice (1.6160.29, p,0.05; Fig. 12A). To determine glial cell response, we examined the gene expression of GFAP, a specific marker for astrocytes, and CD11b, a specific marker for microglia. No changes were observed in either brain areas analyzed in the mRNA expression of GFAP and CD11b when we compared vehicle-injected COX-22/2 with vehicle- injected WT mice (Fig. 11E–F, Fig. 12E–F). In the hippocampus, KA increased the expression of GFAP and CD11b, with a more significant effect in COX-22/2 (GFAP: 3.8360.16, p,0.001; CD11b: 2.4660.20, p,0.01) than in WT mice (GFAP: 2.1460.24, p,0.001; CD11b: 1.9160.19, p,0.01) (Fig. 11E–F). Moreover, KA-injected COX-22/2 mice showed a higher increase in the expression of GFAP (1.8860.13, p,0.01) and CD11b (1.2660.11, p,0.05) when compared with KA- injected WT mice (Fig. 11E–F). In the cortex, KA-injected COX- 22/2 showed an increase in the expression of GFAP (1.8960.17, PLoS ONE | www.plosone.org 13 May 2011 | Volume 6 | Issue 5 | e19398