Comparison of epigenetic modifier transcript levels between liver and brain.

<p>(<b>A</b>) Schematic diagram showing sample preparation and analysis of a set of 156 epigenetic modifier genes. (<b>B</b>) Human hepatocytes were stained 24 h after plating with antibodies specific for dipeptidyl peptidase (DPP4) or albumin (ALB). Nuclei were stained with the DNA dye H-33342 (blue). Data are representative for preparations from three different donors. Scale bars: 100 µm. (<b>C</b>) The mRNA was isolated from three preparations of freshly-isolated hepatocytes and analyzed by RT-qPCR for hepatic (ALB, CYP3A, CYP7A1, DPP4, HNF4, MET) and neuronal (TH, DCX, TUBB3) differentiation markers. Gene expression levels are indicated relative to hESC as reference cell line and a set of three reference genes (HPRT, RPL13A, GAPDH) was used for internal calibration. (<b>D</b>) Transcript levels of epigenetic modifiers were measured by RT-qPCR in human cortex (Ctx), liver (huHep) and embryonic stem cells (hESC). Data for Ctx and huHep are indicated as relative change compared to hESC (as reference cell). For comparative display, a scatter plot was constructed so that differentially expressed genes that show pos. association (between Ctx and huHep) are found in red fields, and those that differed in the sense of regulation fall into blue fields. Values of>10 were set to 10. For quadrant count ratio analysis (QCR) only expression values >2 or <−2 were included. (<b>E</b>) The data measured in D were plotted as heat map, sorted according to rel. Ctx expression levels. Transcripts that were >2-fold higher expressed in tissue than in hESC are marked in red, >2-fold lower expression is marked in blue. The color scale ranges from a fold regulation of −20 (dark blue) to +20 (dark red). Measures of variance and p-values are indicated in the supplemental material, genes not regulated significantly (vs. hESC) are displayed as “n.s.”. Specific examples of differential regulation between Ctx and huHep are emphazised by black boxes.