| First Author | Straccia M | Year | 2011 |
| Journal | J Neuroinflammation | Volume | 8 |
| Pages | 156 | PubMed ID | 22074460 |
| Mgi Jnum | J:303028 | Mgi Id | MGI:6511563 |
| Doi | 10.1186/1742-2094-8-156 | Citation | Straccia M, et al. (2011) Pro-inflammatory gene expression and neurotoxic effects of activated microglia are attenuated by absence of CCAAT/enhancer binding protein beta. J Neuroinflammation 8:156 |
| abstractText | BACKGROUND: Microglia and astrocytes respond to homeostatic disturbances with profound changes of gene expression. This response, known as glial activation or neuroinflammation, can be detrimental to the surrounding tissue. The transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) is an important regulator of gene expression in inflammation but little is known about its involvement in glial activation. To explore the functional role of C/EBPbeta in glial activation we have analyzed pro-inflammatory gene expression and neurotoxicity in murine wild type and C/EBPbeta-null glial cultures. METHODS: Due to fertility and mortality problems associated with the C/EBPbeta-null genotype we developed a protocol to prepare mixed glial cultures from cerebral cortex of a single mouse embryo with high yield. Wild-type and C/EBPbeta-null glial cultures were compared in terms of total cell density by Hoechst-33258 staining; microglial content by CD11b immunocytochemistry; astroglial content by GFAP western blot; gene expression by quantitative real-time PCR, western blot, immunocytochemistry and Griess reaction; and microglial neurotoxicity by estimating MAP2 content in neuronal/microglial cocultures. C/EBPbeta DNA binding activity was evaluated by electrophoretic mobility shift assay and quantitative chromatin immunoprecipitation. RESULTS: C/EBPbeta mRNA and protein levels, as well as DNA binding, were increased in glial cultures by treatment with lipopolysaccharide (LPS) or LPS + interferon gamma (IFNgamma). Quantitative chromatin immunoprecipitation showed binding of C/EBPbeta to pro-inflammatory gene promoters in glial activation in a stimulus- and gene-dependent manner. In agreement with these results, LPS and LPS+IFNgamma induced different transcriptional patterns between pro-inflammatory cytokines and NO synthase-2 genes. Furthermore, the expressions of IL-1beta and NO synthase-2, and consequent NO production, were reduced in the absence of C/EBPbeta. In addition, neurotoxicity elicited by LPS+IFNgamma-treated microglia co-cultured with neurons was completely abolished by the absence of C/EBPbeta in microglia. CONCLUSIONS: These findings show involvement of C/EBPbeta in the regulation of pro-inflammatory gene expression in glial activation, and demonstrate for the first time a key role for C/EBPbeta in the induction of neurotoxic effects by activated microglia. |
