Fig. 4. Maturation of human iHeps.

Gene expression profiling of FPH1-treated (a) and FH1-treated (b) iHeps. Heat map displays of Luminex analysis for 83 liver-specific genes, shown separately for independent experiments. Columns of the heatmap are averaged values of replicate (n≥3) loadings of mRNA extracted from various populations of iPS cells (250ng total RNA per replicate). mRNA expression was determined relative to the average of control gene transferrin, and heat maps are row-normalized. Bar graphs are select gene sets comparing the relative mRNA expression of small molecule-treated hepatocytes (colored bars) to iPS (light gray), untreated iHeps (gray bars) and fetal human hepatocytes (dark gray), normalized to control (black) for nuclear receptors, phase I, phase II and phase III drug metabolism genes. Control refers to adult cryopreserved human primary hepatocytes stabilized by micropatterned co-culture (Adult Control, more details in Supplementary Note 1). Data represent the mean ± SEM of Luminex-loaded replicates. (c) ELISA assays for secreted albumin and AFP, and quantitative CYP3A4 and CYP2A6 activity assays. For all analyses, iHeps were cultured for 9 days post-differentiation, in 6-well plates (n=3). All data presented as mean ± SEM.