Role of Macrophage CCAAT/Enhancer Binding Protein Delta in the Pathogenesis of Rheumatoid Arthritis in Collagen-Induced Arthritic Mice
PLOS ONE
Authors: Chang, Ling-Hua; Huang, Huei-Sheng; Wu, Po-Ting; Jou, I-Ming; Pan, Min-Hsiung; Chang, Wen-Chang; Wang, Dennis Ding Hwa; Wang, Ju-Ming
Abstract
Background: The up-regulation of CCAAT/enhancer binding protein delta (CEBPD) has frequently been observed in macrophages in age-associated disorders, including rheumatoid arthritis (RA). However, the role of macrophage CEBPD in the pathogenesis of RA is unclear. Methodology and Principal Findings: We found that the collagen-induced arthritis (CIA) score and the number of affected paws in Cebpd(-/-) mice were significantly decreased compared with the wild-type (WT) mice. The histological analysis revealed an attenuated CIA in Cebpd(-/-) mice, as shown by reduced pannus formation and greater integrity of joint architecture in affected paws of Cebpd(-/-) mice compared with WT mice. In addition, immunohistochemistry analysis revealed decreased pannus proliferation and angiogenesis in Cebpd(-/-) mice compared with WT mice. CEBPD activated in macrophages played a functional role in promoting the tube formation of endothelial cells and the migration and proliferation of synoviocytes. In vivo DNA binding assays and reporter assays showed that CEBPD up-regulated CCL20, CXCL1, IL23A and TNFAIP6 transcripts through direct binding to their promoter regions. CCL20, IL23A, CXCL1 and TNFAIP6 contributed to the migration and proliferation of synoviocytes, and the latter two proteins were involved in tube formation of endothelial cells. Finally, two anti-inflammatory chemicals, inotilone and rosmanol, reduced the expression of CEBPD and its downstream targets and mitigated the above phenomena. Conclusions and Significance: Collectively, our findings suggest that CEBPD and its downstream effectors could be biomarkers for the diagnosis of RA and potentially serve as therapeutic targets for RA therapy.
NFATc2 mediates epigenetic modification of dendritic cell cytokine and chemokine responses to dectin-1 stimulation
NUCLEIC ACIDS RESEARCH
Authors: Yu, Hong-Bing; Yurieva, Marina; Balachander, Akhila; Foo, Ivy; Leong, Xiangrong; Zelante, Teresa; Zolezzi, Francesca; Poidinger, Michael; Ricciardi-Castagnoli, Paola
Abstract
The transcription factor NFATc2 regulates dendritic cell (DC) responses to microbial stimulation through the C-type lectin receptor dectin-1. But the genetic targets of NFATc2 and their effects on DC function remain largely unknown. Therefore we used ChIP-seq to conduct genome-wide mapping of NFATc2 target sites in dectin-1-activated DCs. By combining binding-site data with a comprehensive gene expression profile, we found that NFATc2 occupancy regulates the expression of a subset of dectin-1-activated genes. Surprisingly, NFATc2 targeted an extensive range of DC-derived cytokines and chemokines, including regulatory cytokines such as IL2, IL23a and IL12b. Furthermore, we demonstrated that NFATc2 binding is required to induce the histone 3 lysine 4 trimethylation (H3K4me3) epigenetic mark, which is associated with enhanced gene expression. Together, these data show that the transcription factor NFATc2 mediates epigenetic modification of DC cytokine and chemokine genes leading to activation of their expression.