Functional activity of cultured cells.

<p>In PHH activity of CYP3A4 was determined after stimulation with 25μM dexamethasone for 6-48h. In addition CYP3A4 was inhibited by treatment with 2% DMSO. Cells were treated with ETOH or DMSO as negative controls. Relative light units (RLU) are given as mean±SEM (n = 3). Furthermore, CYP3A4 and albumin fluorescence imaging revealed a heterogeneous pattern of cultured PHH (A). KC exhibited strong phagocytic activity by the uptake of 1μm fluorescent latex beads (green) in a time-dependent manner (B). LSEC exhibited efficient endocytic capability, shown by the efficient incorporation of AcLDL (green) after 1h of incubation which was metabolized after incubation for 6h (C). HSC, cultured for a short time, were visualized by retinol (vitamin A) autofluorescence signals. Brightness reinforcement (BrightR) detection mode was used to amplify dim structures and make them accessible. To distinguish HSC from myofibroblasts, CYGB (green) and α-SMA (red) were fluorescently stained in the HSC population. Nuclei were stained with DAPI (blue). Images were taken at 40× magnification. Scale bar, 50μm. Furthermore, RNA was extracted from freshly isolated (uncultured) HSC and HSC cultured for 10 days (n = 6). Gene expression of <i>ACTA2</i>, <i>COL1A1</i> and <i>LOXL2</i> was determined by RT-qPCR. Data represent mean of copy numbers (mean±SEM) normalized to the reference gene <i>ACTB</i> (D). Asterisks indicate significant results (* p<0.05; ** p<0.01; *** p<0.001).