Journal: EBioMedicine
Article Title: LRH1-driven transcription factor circuitry for hepatocyte identity: Super-enhancer cistromic analysis
doi: 10.1016/j.ebiom.2018.12.056
Figure Lengend Snippet: LRH1 as a driver gene for the core TF circuitry. (A) Hepatic super-enhancer-associated TF network with gene expression changes in mice treated with APAP alone or APAP+LRH1 overexpression vector. The node colors reflect log2 gene expression ratio in mice treated with APAP alone (left) or APAP+LRH1 overexpression (right) as compared to vehicle treatment (red, upregulation; blue, downregulation). Log2 fold changes of the core TFs are presented as an inset table. (B) The core TF mRNA levels from the APAP model. (C) The core TF mRNA levels from the CCl 4 model. (D) The effect of each core TF overexpression on other core TFs. qRT-PCR assays were done on AML12 cells transfected with pcDNA3.1, LRH1, HNF4α, PPARα or RXRα for 48 h. The first lane of each graph is transfection reagent-treated control. Heatmap presents averages of core TF mRNA levels. O/E, overexpression. (E) Super-enhancer (SE)-luciferase reporter assays. Luciferase assays were done on AML12 cells co-transfected with each SE-luciferase reporter, and pcDNA3.1, LRH1, HNF4α, PPARα or RXRα overexpression vector for 24 h. Relative luciferase activities represent arbitrary units of luminescence normalized to the pcDNA3.1 group. The schematic illustrations showing each SE-luciferase construct are presented in the upper panel. The ChIP-seq signal peaks in the scheme are also shown in F. Red bars indicate the peaks excised for cloning of each SE-luciferase reporter construct. O/E, overexpression. (F) A proposed scheme showing auto-regulatory loops for the core TFs. In healthy liver, the core TFs form an interconnected feedback loop for gene expression. Upon injury, the signal circuitry loses its integrity with decrease of hepatocyte identity. LRH1 serves a driver for reconstitution of the signal circuitry. Data information: For B, data represent the means ± SEM (Mock+Veh, n = 7; Mock+APAP, n = 8; and LRH1 + APAP, n = 13, significantly different as compared to vehicle control, ** P < .01; or APAP-treated control, # P < .05; ## P < .01). For C, data represent the means ± SEM (Mock+Veh, n = 6; Mock+CCl 4 , n = 14; and LRH1 + CCl 4 , n = 4; significantly different as compared to vehicle control, * P < .05; ** P < .01; or CCl 4 -treated control: # P < .05; ## P < .01). For D and E, data represent the means ± SEM ( n = 3 each, significantly different as compared to pcDNA3.1 group, * P < .05; ** P < .01). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Article Snippet: The plasmids encoding mouse LRH1 (#16342, RRID: Addgene_16,342) and mouse PPARα (#22751, RRID: Addgene_22,751) were supplied from Addgene (Cambridge, MA).
Techniques: Gene Expression, Over Expression, Plasmid Preparation, Quantitative RT-PCR, Transfection, Control, Luciferase, Construct, ChIP-sequencing, Cloning