Publications by authors named "Takafumi Akabane"

The first microfluidic microphysiological systems (MPS) entered the academic scene more than 15 years ago and were considered an enabling technology to human (patho)biology in vitro and, therefore, provide alternative approaches to laboratory animals in pharmaceutical drug development and academic research. Nowadays, the field generates more than a thousand scientific publications per year. Despite the MPS hype in academia and by platform providers, which says this technology is about to reshape the entire in vitro culture landscape in basic and applied research, MPS approaches have neither been widely adopted by the pharmaceutical industry yet nor reached regulated drug authorization processes at all.

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A limited understanding of intersubject and intrasubject variability hampers effective biomarker translation from in vitro/in vivo studies to clinical trials and clinical decision support. Specifically, variability of biomolecule concentration can play an important role in interpretation, power analysis, and sampling time designation. In the present study, a wide range of 749 plasma metabolites, 62 urine biogenic amines, and 1,263 plasma proteins were analyzed in 10 healthy male volunteers measured repeatedly during 12 hours under tightly controlled conditions.

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Vascular Adhesion Protein-1 (VAP-1) is a promising therapeutic target for the treatment of several inflammatory-related diseases including diabetic microvascular complication. We identified glycine amide derivative 3 as a novel structure with moderate VAP-1 inhibitory activity. Structure-activity relationship studies of glycine amide derivatives revealed that the tertiary amide moiety is important for stability in rat blood and that the position of substituents on the left phenyl ring plays an important role in VAP-1 inhibitory activity.

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Triple-negative breast cancer (TNBC) has a poor prognosis compared to other subtypes, and effective treatment options are limited to cytotoxic agents, including microtubule-targeting agents, due to the lack of molecular targets. Here, we examined the combined effect of sepantronium bromide (YM155) and microtubule-targeting agents in TNBC models. The combination of YM155 with docetaxel showed synergistic antiproliferative and caspase 3/7-inducing effects in MRK-nu-1 and MDA-MB-453 human TNBC cell lines in vitro.

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We describe the usability of human pooled hepatocytes for non-CYP metabolism evaluation and an in vivo-in vitro correlation analysis for aldehyde oxidase (AO) substrate compounds using pooled hepatocytes. By comparing intrinsic clearance values of 18 compounds primarily metabolized by AO, UDP-glucuronosyltransferase, carbonyl/aldo-keto reductase, flavin-containing monooxygenase, and monoamineoxidase in individual hepatocytes and pooled hepatocytes from the same individual donors, intrinsic clearance in the pooled hepatocytes was ± 30% of the average clearance value in individuals for 15 of 18 compounds, suggesting that pooled hepatocytes maintained the average activity of the individual hepatocytes. Although the results of an in vivo-in vitro correlation analysis for AO substrate compounds showed a trend toward under-prediction, the underestimation ratios for all AO substrates were nevertheless comparable (7.

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Human hepatocytes are a physiologically relevant tool useful in evaluating liver-related pharmacokinetics, including non-cytochrome P-450 (CYP) metabolism, due to their broad spectrum of metabolic enzyme activity. To verify the usefulness of human hepatocytes in evaluating non-CYP metabolism for drug discovery, we compared intrinsic clearance values (CL(int)) in freshly isolated and cryopreserved hepatocytes using 14 compounds primarily metabolized by non-CYP enzymes, including UDP-glucuronosyltransferase, carbonyl/aldo-keto reductase, aldehyde oxidase, flavin-containing monooxygenase, and monoamineoxidase. Cryopreservation resulted in a >20% reduction (maximum: 50%) in CL(int) in 7/14 compounds (statistically significant for 5 compounds) on comparing CL(int) values in freshly isolated and cryopreserved hepatocytes from the same donors (n = 4).

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We describe the preclinical and clinical pharmacokinetic profiles of FK3453 [6-(2-amino-4-phenylpyrimidin-5-yl)-2-isopropylpyridazin-3(2H)-one] and the mechanism responsible for poor oral exposure of FK3453 in humans. FK3453 showed favourable profiles in preclinical pharmacokinetic studies, including satisfactory absolute bioavailability and total body clearance in animals (30.5%-41.

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This study aimed to establish a practical and convenient method of predicting intestinal availability (F(g)) in humans for highly permeable compounds at the drug discovery stage, with a focus on CYP3A4-mediated metabolism. We constructed a "simplified F(g) model," described using only metabolic parameters, assuming that passive diffusion is dominant when permeability is high and that the effect of transporters in epithelial cells is negligible. Five substrates for CYP3A4 (alprazolam, amlodipine, clonazepam, midazolam, and nifedipine) and four for both CYP3A4 and P-glycoprotein (P-gp) (nicardipine, quinidine, tacrolimus, and verapamil) were used as model compounds.

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To verify the availability of pharmacokinetic parameters in cynomolgus monkeys, hepatic availability (Fh) and the fraction absorbed multiplied by intestinal availability (FaFg) were evaluated to determine their contributions to absolute bioavailability (F) after intravenous and oral administrations. These results were compared with those for humans using 13 commercial drugs for which human pharmacokinetic parameters have been reported. In addition, in vitro studies of these drugs, including membrane permeability, intrinsic clearance, and p-glycoprotein affinity, were performed to classify the drugs on the basis of their pharmacokinetic properties.

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