cell type, study type, assay type, strain, compound, dose, dose unit, dose duration, duration unit, dose frequency: primary human hepatocytes assay type: in vitro study type: single dose toxicity strain: Hu8119+Hu1591+Hu1540 dose: DMSO 0.5 % dose duration: 3 days
After quick thawing in a water bath at 37°C, viability of the cells was checked by a Trypan blue (CAS no. 72-57-1, Sigma–Aldrich) exclusion test as instructed in the supplier’s protocol (Invitrogen, 2012). All viability scores after thawing were in agreement with those listed by the supplier. Before CsA treatment, cells were allowed to acclimatize for 48 hours. This is needed for the hepatocytes to restore an in vivo like cellular configuration and enzyme expression levels as optimally as possible. PHH were treated with 30 µM CsA for 5 days daily followed by a washout-period (terminating CsA-treatment) of 3 days.
Cryopreserved primary human hepatocytes (PHH) were purchased from Life Technologies. Cells were cultured in pre-coated 24-well plates (2,100,000 cells/sample) in a 2-layer collagen sandwich (A11428-02, Gibco), according to the supplier’s protocol (Invitrogen, 2012). The following culture media were used: Hepatocyte Thawing Medium (HTM) for thawing (CM7500, Gibco), Williams’ Medium E (1x, no phenol red) (A1217601, Gibco) + Cell Maintenance supplement B kit (CM4000, Gibco) for plating and incubation.
Cells were cultured in triplicate in 24 wells in a collagen sandwich layer. Following 5 days of repetitive daily exposureand thereupon a washout of 3 days, cells lysates were harvested for total RNA isolation after 3, 5 and 8 days. Therefore, medium was removed and PHH were harvested in Qiazol (Qiagen). Total RNA was isolated using a miRNeasy Mini Kit (Qiagen) according to the manufacturer’s protocol and followed by DNase I (Qiagen) treatment. Upon purification, RNA concentrations were measured by means of a NanoDrop® ND-1000 spectrophotometer (Thermo Scientific) at 260 and 280 nm. RNA quality and integrity were assessed by using automated gel electrophoresis on an Agilent 2100 Bioanalyzer system (Agilent Technologies). Only RNA samples which showed clear 18S and 28S peaks and with an RNA integrity number (RIN) higher than 6, were used. Samples were stored at -80ºC until RNA hybridization.
High-density oligonucleotide GeneChips from Affymetrix were used to measure gene expression levels (Human Genome U133 Plus 2.0 array (604,258 probes)). Targets for these arrays were prepared, hybridized and scanned according to the Affymetrix protocol (Affymetrix).Normalization quality controls appeared to be within acceptable limits for almost all chips.
Amplified, biotinylated and fragmented targets were then hybridized on to the BrainArray custom CDF v15.1.0 array.
After hybridization, arrays were washed and stained using an Affymetrix fluidics station and scanned by use of an Affymetrix GeneArray scanner. A total of 60 RNA samples was prepared and analyzed on GeneChip arrays (treated and control samples from each time point were at least in triplicate). Normalization quality controls, including scaling factors, average intensities, present calls, background intensities, noise, and raw Q values, appeared to be within acceptable limits for all chips. Hybridization controls BioB, BioC, BioD, and CreX were called present on all chips and yielded the expected increases in intensities.
The Arrayanalysis.org web service was used for quality control (27) and all microarrays were of high quality. CEL files were imported into R v2.15.3 (http://www.r-project.org) using the “affy” library (28) within BioConductor (v2.9) (29). Probe re-annotation, normalization and data filtering was performed as previously described (30).