DUX4 is a multifunctional factor priming human embryonic genome activation

Double homeobox 4 (DUX4) is expressed at the early pre-implantation stage in human embryos. Here we show that induced human DUX4 expression substantially alters the chromatin accessibility of non-coding DNA and activates thousands of newly identified transcribed enhance-like regions, preferentially located within ERVL-MaLR repeat elements. CRISPR activation of transcribed enhancers by C-terminal DUX4 motifs results in the increased expression of target embryonic genome activation (EGA) genes ZSCAN4 and KHDC1P1. We show that DUX4 is markedly enriched in human zygotes, followed by intense nuclear DUX4 localization preceding and coinciding Kith minor EGA. DUX4 knockdown in human zygotes led to changes in the EGA transcriptome but did not terminate the embryos. We also show that the DUX4 protein interacts with the Mediator complex via the C-terminal KIX binding motif. Our findings contribute to the understanding of DUX4 as a regulator of the non-coding genome.Peer reviewe

Viral infection-related gene upregulation in monocytes in children with signs of β-cell autoimmunity

Abstract Objective: The pathogenesis of type 1 diabetes (T1D) is associated with genetic predisposition and immunological changes during presymptomatic disease. Differencesin immune cell subset numbers and phenotypes between T1D patients and healthy controls have been described; however, the role and function of these changes in the pathogenesis is still unclear. Here we aimed to analyze the transcriptomic landscapes of peripheral blood mononuclear cells (PBMCs) during presymptomatic disease. Methods: Transcriptomic differences in PBMCs were compared between cases positive for islet autoantibodies and autoantibody negative controls (9 case–control pairs)and further in monocytes and lymphocytes separately in autoantibody positive subjects and control subjects (25 case–control pairs). Results: No significant differential expression was found in either data set. However, when gene set enrichment analysis was performed, the gene sets “defence response to virus” (FDR <0.001, ranking 2), “response to virus” (FDR <0.001, ranking 3) and “response to type I interferon” (FDR=0.002, ranking 12) were enriched in the upregulated genes among PBMCs in cases. Upon further analysis, this was also seen in monocytes in cases (FDR=0.01, ranking 2; FDR=0.04, ranking 3 and FDR=0.02, ranking 1, respectively) but not in lymphocytes. Conclusion: Gene set enrichment analysis of children with T1D-associated autoimmunity revealed changes in pathways relevant for virus infection in PBMCs, particularly in monocytes. Virus infections have been repeatedly implicated in the pathogenesis of T1D. These results support the viral hypothesis by suggesting altered immune activation of viral immune pathways in monocytes during diabetes