An in vitro coculture system of human peripheral blood mononuclear cells with hepatocellular carcinoma-derived cells for predicting drug-induced liver injury.

Preventing clinical drug-induced liver injury (DILI) remains a major challenge, because DILI develops via multifactorial mechanisms. Immune and inflammatory reactions are considered important mechanisms of DILI; however, biomarkers from in vitro systems using immune cells have not been comprehensively studied. The aims of this study were (1) to identify promising biomarker genes for predicting DILI in an in vitro coculture model of peripheral blood mononuclear cells (PBMCs) with a human liver cell line, and (2) to evaluate these genes as predictors of DILI using a panel of drugs with different clinical DILI risk. Transcriptome-wide analysis of PBMCs cocultured with HepG2 or differentiated HepaRG cells that were treated with several drugs revealed an appropriate separation of DILI-positive and DILI-negative drugs, from which 12 putative biomarker genes were selected. To evaluate the predictive performance of these genes, PBMCs cocultured with HepG2 cells were exposed to 77 different drugs, and gene expression levels in PBMCs were determined. The MET proto-oncogene receptor tyrosine kinase (MET) showed the highest area under the receiver-operating characteristic curve (AUC) value of 0.81 among the 12 genes with a high sensitivity/specificity (85/66%). However, a stepwise logistic regression model using the 12 identified genes showed the highest AUC value of 0.94 with a high sensitivity/specificity (93/86%). Taken together, we established a coculture system using PBMCs and HepG2 cells and selected biomarkers that can predict DILI risk. The established model would be useful in detecting the DILI potential of compounds, in particular those that involve an immune mechanism.

Effects of combined treatment with fesoterodine and mirabegron in a pelvic congestion rat model: Results from in vitro and in vivo functional studies.

OBJECTIVES: To examine the effect of combining a nonselective muscarinic receptor antagonist, 5-hydroxymethyl tolterodine (an active metabolite of fesoterodine), with a ß3 adrenoceptor agonist, mirabegron, in a rat model of pelvic congestion. METHODS: The rat pelvic congestion model used female Sprague-Dawley rats with their bilateral common iliac and uterine veins ligated. Expressions of M2 and M3 receptor subtypes in the urothelium and detrusor were detected by real-time polymerase chain reaction assays. The effects of both drugs were investigated on isolated bladder strips contracted by electrical field stimulation. in vivo single cystometry was used to assess the effects of 5-hydroxymethyl tolterodine and mirabegron independently or in combination on bladder capacity, micturition pressure, and threshold pressure. RESULTS: Pelvic congestion rats showed decreased bladder capacity compared with controls, but micturition pressure and threshold pressure were unchanged. Pelvic congestion model rats also demonstrated an approximately two-fold increase in expression of both M2 and M3 receptor subtypes in the urothelium. Additive relaxant effects of 5-hydroxymethyl tolterodine and mirabegron were observed in vitro in the electrical field stimulation-induced contractions of bladder strips from pelvic congestion rats. In vivo, bladder capacity was increased significantly by a combination of 5-hydroxymethyl tolterodine and mirabegron, with the combined effect exceeding the sum of the effects of monotherapies. Micturition pressure and threshold pressure did not significantly differ between groups. CONCLUSIONS: The combination of 5-hydroxymethyl tolterodine with mirabegron suggests the potential of synergistic effects in a rat pelvic congestion model.

Potentials and limitations of nonclinical safety assessment for predicting clinical adverse drug reactions: correlation analysis of 142 approved drugs in Japan.

The objective of this study was to elucidate the range of abilities of nonclinical safety assessment for predicting adverse drug reactions (ADRs) in humans. The dataset included 1256 ADRs with an incidence rate of 5% or more collected from 142 drugs approved in Japan from 2001 to 2010 (excluding anticancer agents and vaccines). Gastrointestinal, neurological and hepatobiliary ADRs were relatively common, followed by hematological, cutaneous, systemic and cardiovascular ADRs in the dataset. The analysis revealed that 48% of ADRs were predictable based on a comprehensive nonclinical safety assessment considering animal toxicity. Hematological and ocular ADRs, infection, and application site reactions showed a correlation of more than 70%, while musculoskeletal, respiratory and neurological ADRs showed a correlation of less than 30%. In addition to subjective patient perceptions, several laboratory parameters routinely monitored both in animals and humans showed a lower correlation, e.g., abnormalities in hepatobiliary and metabolic parameters, and blood pressure increase. Large molecule drugs showed lower correlation than small molecule drugs; ADRs were observed in various organs and consideration of pharmacological action did not significantly contribute to the prediction. It was also confirmed that the current standard of toxicology testing regarding dosing duration and dose level is adequate to detect concordant animal toxicity. This study collectively demonstrated a significant value of nonclinical safety assessment in predicting ADRs in humans. It also identified the subset of ADRs with poor predictability, highlighting the need for advanced testing that enables successful translation of animal toxicity to clinical settings with better accuracy and sensitivity.

Discovery of (-)-6-[2-[4-(3-fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone--a potent NR2B-selective N-methyl D-aspartate (NMDA) antagonist for the treatment of pain.

(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone was identified as an orally active NR2B-subunit selective N-methyl-d-aspartate (NMDA) receptor antagonist. It has very high selectivity for NR2B subunits containing NMDA receptors versus the HERG-channel inhibition (therapeutic index=4200 vs NR2B binding IC(50)). This compound has improved pharmacokinetic properties compared to the prototype CP-101,606.