Expression profile of cytochrome P450s and effects of polycyclic aromatic hydrocarbons and antiepileptic drugs on CYP1 expression in MOG-G-CCM cells.

Aims: This study was performed to investigate the expression profile of cytochrome P450 (CYP) isoforms and effects of polycyclic aromatic hydrocarbons (PAHs) and antiepileptic drugs on CYP1 expression in human astrocytoma MOG-G-CCM cells.

Main Methods: CYP1A1 and CYP1B1 expression were determined by quantitative real-time polymerase chain reaction, Western blotting, and immunocytochemistry.

Key Findings: MOG-G-CCM cells expressed various CYP isoforms.

In Vitro Inhibitory Effects of Sesamin on CYP4F2 Activity.

Sesamin is a major lignan in sesame seeds, and a recent meta-analysis of controlled trials indicated that sesamin intake decreases blood pressure. The antihypertensive effect of sesamin has been suggested to be due to sesamin-mediated suppression of 20-hydroxyeicosatetraenoic acid production catalyzed by CYP4F2. However, the detailed mechanism underlying inhibition of CYP4F2 function by sesamin remains unclear.

Evaluation of human embryonic stem cell-derived hepatocyte-like cells for detection of CYP1A inducers.

There is a great deal of interest in differentiation of human embryonic stem cells (hESCs) into hepatocyte-like cells for application in pharmaceutical screening. Cytochrome P450 (CYP) 1A is involved in the metabolic activation of procarcinogenic compounds as well as in detoxification of drugs. We differentiated hESCs into hepatocyte-like cells (hESC-derived hepatocyte-like cells) and examined whether CYP1A was induced in these cells by typical inducers of CYP1A.

Lower expression of HNF4α and PGC1α might impair rifampicin-mediated CYP3A4 induction under conditions where PXR is overexpressed in human fetal liver cells.

Pregnane X receptor (PXR) mRNA was detected in HepG2 cells by RT-PCR, but not in human fetal liver (HFL) cells. CYP3A4 was induced by rifampicin (RIF), mifepristone (RU486), clotrimazole (CTZ), and dexamethasone (DEX) in HepG2 cells, while these PXR ligands with the exception of DEX did not induce CYP3A4 mRNA expression in HFL cells. Ad-PXR infection increased mRNA levels of PXR and CYP3A4 in both cells despite the absence of PXR ligands.

Formation of large vacuoles induced by cooperative effects of oncostatin M and dexamethasone in human fetal liver cells.

The morphology of human fetal liver cells treated with both oncostatin M and dexamethasone was strikingly different from those of cells treated with either oncostatin M or dexamethasone alone. Cotreatment with oncostatin M and dexamethasone resulted in the appearance of numerous large vacuoles. The size of the vacuoles varied among individual cells, ranging from 0.