Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Various adaptive cellular stress response pathways are critical in the pathophysiology of liver disease and drug-induced liver injury. Human-induced pluripotent stem cell (hiPSC)-derived hepatocyte-like cells (HLCs) provide a promising tool to study cellular stress response pathways, but in this context there is limited insight on how HLCs compare to primary human hepatocytes (PHH). Here, we systematically compared the activation of four different stress pathways in PHH, HepG2 liver cancer cells, hiPSCs and different stages within the differentiation towards HLCs (definitive endoderm, hepatoblast, immature hepatocytes and HLCs). We exposed all different cell types in a concentration response to four different compounds that specifically activate the oxidative stress response (diethyl-maleate), unfolded protein response (tunicamycin), DNA damage response (cisplatin) and inflammatory signalling (TNF). We used targeted RNA-sequencing to map concentration response transcriptional similarities and differences using bench-mark concentration modelling for the various stress responses in the different test systems. We observed that HLCs are more sensitive to oxidative stress than PHH showing activation at ten-fold lower concentrations and induce a strong anti-oxidant response. Although similar UPR gene sets were activated in HLCs compared to PHH, PHH were about ten times more sensitive. Furthermore, HLCs were highly sensitive to inflammation conditions similar to HepG2 cells and in sharp contrast to hiPSC, which showed hardly any response. On the contrary, hiPSC and HepG2 were highly sensitive to DNA damage signalling while HLCs resisted a strong p53 DNA damage response upon exposure. Overall, the data indicate that despite limitation in full hepatocyte maturation, HLCs did gain specific adaptive cellular stress response networks that mimic those of PHHs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Primary human hepatocytes (PHHs) are a liver-specific cell subtype, and we have shown that these cells respond in a unique manner to the introduction of hepatitis C viral RNA (HCV vRNA) derived from different genotypes of the virus. We used microarray to analyze the transcriptional differences between the PHHs exposed to the different genotypes of HCV to further shed light on their differential effects on HCV innate immune responses in vitro HCV vRNA from either genotype 3a HCV or genotype 1a HCV was introduced into the PHH cells for 8 hours. Total RNA was then harvested to determine transcriptional differences.
Project description:Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is commonly used as a surrogate for human hepatocytes, but their use in ADME and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite their widespread use, the transcriptome of HepG2 cells compared to PHH is not well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the naïve HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin, which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. While TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH, and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity. Keywords: Cell Type Comparison