Anti-IRF8 polyclonal antibody

Introduction: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Currently, numerous genetic loci of SLE have been confirmed. Here we try to further explore additional genes contributing to SLE susceptibility in this study. Methods: Forty nine single nucleotide polymorphisms (SNPs) with moderate-risk for SLE in previous study were genotyped in a large-scale replication study with a total of 3,522 cases and 8,252 controls using the Sequenom Massarray system. Association analyses were performed using logistic regression with gender or sample cohorts as a covariate through PLINK 1.07 software. Results: This replication effort confirmed five reported SLE susceptibility loci reaching genome-wide levels of significance (P-meta < 5.00 x 10(-08)): TNFSF4 (rs1418190, odds ratio (OR) = 0.81, P-meta = 1.08 x 10(-08); rs4916219, OR = 0.80, P-meta = 7.77x 10(-09)), IRF8 (rs2934498, OR = 1.25, P-meta = 4.97 x 10(-09)), miR-146a (rs2431697, OR = 0.69, P-meta = 1.15 x 10(-22)), CD44 (rs2732547, OR = 0.82, P-meta = 1.55 x 10(-11)), and TMEM39A (rs12494314, OR = 0.84, P-meta= 1.01x 10(-09)). Further logistic regression analysis indicated that the genetic effects within TNFSF4 detected in this study are independent from our previously reported signals. Conclusions: This study increases the number of established susceptibility loci for SLE in Han Chinese population and highlights the contribution of multiple variants of modest effect. Although further studies will be required to identify the causal alleles within these loci, the findings make a significant step forward in our understanding of the genetic contribution to SLE in Chinese population.

Receptor activator of nuclear factor kappa B ligand (RANKL) induces osteoclast (OC) differentiation from bone marrow-derived macrophages (BMMs). The transcription factors nuclear factor of activated T cells 1 (NFATc1) and interferon regulatory factor (IRF) 8 play positive and negative roles, respectively, in this process. However, genomewide mapping of the active cis-regulatory elements regulating OC differentiation has not been performed, and little is known about the global landscape of OC-specific gene regulation. We used chromatin immunoprecipitation and formaldehyde-assisted isolation of regulatory elements followed by sequencing to show that PU.1 transcription factor binding motifs were overrepresented at active cis-regulatory regions in both murine BMMs and OCs, while IRF and NFAT binding motifs were selectively enriched at these regions in BMMs and OCs, respectively. We also found that RANKL induced the downregulation of Irf8 and upregulation of Nfatc1 expression, which was associated with dramatic alterations in histone modification. BMM-specific PU.1 binding sites were observed to overlap with IRF8 binding sites in BMMs, and this also occurred for OC-specific PU.1 binding sites and NFATc1 binding sites in OCs. The expression of genes with IRF8 peaks within BMM-specific PU.1 binding sites was significantly higher in BMMs than in OCs, while that of genes with NFATc1 peaks within OC-specific PU.1 binding sites was significantly higher in OCs than in BMMs. Our results suggest that PU.1 switches its transcription partner from IRF8 to NFATc1 and alters the binding regions during RANKL-induced osteoclastogenesis, which is associated with changes in epigenetic profiles and the control of cell type-specific gene expression. (c) 2019 American Society for Bone and Mineral Research.