Project description:We address the function of HNF6 in the mouse liver metabolism and Rev-erba cistrome We performed Rev-erba ChIP-seq in mouse livers at 5pm of the day and compared between WT and HNF6-depleted livers.
Project description:We address the function of HNF6 in the mouse liver metabolism and Rev-erba cistrome We performed microarray in mouse livers at 5pm of the day and compared between WT and HNF6-depleted livers.
Project description:The circadian clock regulates behavioural and physiological processes in a 24-h cycle. The nuclear receptors REV-ERBa and REV-ERBb are involved in the cell-autonomous circadian transcriptional/translational feedback loops as transcriptional repressors. A number of studies have also demonstrated a pivotal role of REV-ERBs in regulation of metabolic, neuronal, and inflammatory functions including bile acid metabolism, lipid metabolism, and production of inflammatory cytokines. Given the multifunctional role of REV-ERBs, it is important to elucidate the mechanism through which REV-ERBs exert their functions. To this end, we established a Rev-erba/Rev-erbb double-knockout mouse embryonic stem (ES) cell model and analyzed the circadian clock and clock-controlled output gene expressions. A comprehensive mRNA-seq analysis revealed that the complete knockout of both Rev-erba and Rev-erbb does not abrogate expression rhythms of E-box-regulated core clock genes but drastically changes a diverse set of other rhythmically-expressed output genes. Of note, REV-ERBa/b deficiency does not compromise circadian expression rhythms of PER2, while REV-ERB target genes, Bmal1 and Npas2, are significantly upregulated. This study emphasizes REV-ERBs function to form an essential link between the circadian clock and a wide variety of cellular physiological functions.
Project description:RORγt is well recognized as the lineage defining transcription factor for TH17 cell development. However, the cell-intrinsic mechanisms that negatively regulate TH17 cell development and autoimmunity remain poorly understood. Here we demonstrate that the transcriptional repressor REV-ERBa is exclusively expressed in TH17 cells, competes with RORγt for their shared DNA consensus sequence, and negatively regulates TH17 cell development via repression of genes traditionally characterized as RORγt-dependent, including Il17a. Deletion of REV-ERBa enhanced TH17-mediated pro-inflammatory cytokine expression, exacerbating experimental autoimmune encephalomyelitis (EAE) and colitis. Treatment with REV-ERB-specific synthetic ligands, which have similar phenotypic properties as RORγ modulators, suppressed TH17 cell development, was effective in colitis intervention studies, and significantly decreased the onset, severity, and relapse rate in several models of EAE without affecting thymic cellularity. Our results establish that REV-ERBa negatively regulates pro-inflammatory TH17 responses in vivo and identifies the REV-ERBs as potential targets for the treatment of TH17-mediated autoimmune diseases.
Project description:Hepatocyte nuclear factor 6 (HNF6) is required for liver development, but its role in adult liver metabolism is not known. Here we show that deletion of HNF6 in livers of adult C57Bl/6 mice leads to hepatic steatosis in mice fed normal laboratory chow. Although HNF6 is known mainly as a transcriptional activator, hepatic loss of HNF6 up-regulated many lipogenic genes bound directly by HNF6. Many of these genes are targets of the circadian nuclear receptor Rev-erbα, and binding of Rev-erbα at these sites was lost when HNF6 was ablated in the liver. While HNF6 and Rev-erbα coordinately regulate hepatic lipid metabolism, each factor also affects additional gene sets independently. These findings highlight a novel mechanism of transcriptional repression by HNF6 and demonstrate how overlapping and distinct mechanisms of transcription factor function contribute to the integrated physiology of the liver.