| First Author | Pulido-Salgado M | Year | 2017 |
| Journal | J Neuroinflammation | Volume | 14 |
| Issue | 1 | Pages | 54 |
| PubMed ID | 28302135 | Mgi Jnum | J:360229 |
| Mgi Id | MGI:7797549 | Doi | 10.1186/s12974-017-0834-5 |
| Citation | Pulido-Salgado M, et al. (2017) Myeloid C/EBPbeta deficiency reshapes microglial gene expression and is protective in experimental autoimmune encephalomyelitis. J Neuroinflammation 14(1):54 |
| abstractText | BACKGROUND: CCAAT/enhancer binding protein beta (C/EBPbeta) is a transcription factor that regulates the expression of important pro-inflammatory genes in microglia. Mice deficient for C/EBPbeta show protection against excitotoxic and ischemic CNS damage, but the involvement in this neuroprotective effect of the various C/EBPbeta-expressing cell types is not solved. Since C/EBPbeta-deficient microglia show attenuated neurotoxicity in culture, we hypothesized that specific C/EBPbeta deficiency in microglia could be neuroprotective in vivo. In this study, we have tested this hypothesis by generating mice with myeloid C/EBPbeta deficiency. METHODS: Mice with myeloid C/EBPbeta deficiency were generated by crossing LysMCre and C/EBPbeta(fl/fl) mice. Primary microglial cultures from C/EBPbeta(fl/fl) and LysMCre-C/EBPbeta(fl/fl) mice were treated with lipopolysaccharide +/- interferon gamma (IFNgamma) for 6 h, and gene expression was analyzed by RNA sequencing. Gene expression and C/EBPbeta deletion were analyzed in vivo in microglia isolated from the brains of C/EBPbeta(fl/fl) and LysMCre-C/EBPbeta(fl/fl) mice treated systemically with lipolysaccharide or vehicle. Mice of LysMCre-C/EBPbeta(fl/fl) or control genotypes were subjected to experimental autoimmune encephalitis and analyzed for clinical signs for 52 days. One- or two-way ANOVA or Kruskal-Wallis with their appropriate post hoc tests were used. RESULTS: LysMCre-C/EBPbeta(fl/fl) mice showed an efficiency of C/EBPbeta deletion in microglia of 100 and 90% in vitro and in vivo, respectively. These mice were devoid of female infertility, perinatal mortality and reduced lifespan that are associated to full C/EBPbeta deficiency. Transcriptomic analysis of C/EBPbeta-deficient primary microglia revealed C/EBPbeta-dependent expression of 1068 genes, significantly enriched in inflammatory and innate immune responses GO terms. In vivo, microglial expression of the pro-inflammatory genes Cybb, Ptges, Il23a, Tnf and Csf3 induced by systemic lipopolysaccharide injection was also blunted by C/EBPbeta deletion. CNS expression of C/EBPbeta was upregulated in experimental autoimmune encephalitis and in multiple sclerosis samples. Finally, LysMCre-C/EBPbeta(fl/fl) mice showed robust attenuation of clinical signs in experimental autoimmune encephalitis. CONCLUSION: This study provides new data that support a central role for C/EBPbeta in the biology of activated microglia, and it offers proof of concept for the therapeutic potential of microglial C/EBPbeta inhibition in multiple sclerosis. |
