Katsume A.,Tokyo Metropolitan Institute of Medical Science |
Katsume A.,Chugai Pharmaceutical Co. |
Tokunaga Y.,Tokyo Metropolitan Institute of Medical Science |
Hirata Y.,Tokyo Metropolitan Institute of Medical Science |
And 14 more authors.
Gastroenterology | Year: 2013
Background & Aims Host cell lipid rafts form a scaffold required for replication of hepatitis C virus (HCV). Serine palmitoyltransferases (SPTs) produce sphingolipids, which are essential components of the lipid rafts that associate with HCV nonstructural proteins. Prevention of the de novo synthesis of sphingolipids by an SPT inhibitor disrupts the HCV replication complex and thereby inhibits HCV replication. We investigated the ability of the SPT inhibitor NA808 to prevent HCV replication in cells and mice. Methods We tested the ability of NA808 to inhibit SPT's enzymatic activity in FLR3-1 replicon cells. We used a replicon system to select for HCV variants that became resistant to NA808 at concentrations 4- to 6-fold the 50% inhibitory concentration, after 14 rounds of cell passage. We assessed the ability of NA808 or telaprevir to inhibit replication of HCV genotypes 1a, 1b, 2a, 3a, and 4a in mice with humanized livers (transplanted with human hepatocytes). NA808 was injected intravenously, with or without pegylated interferon alfa-2a and HCV polymerase and/or protease inhibitors. Results NA808 prevented HCV replication via noncompetitive inhibition of SPT; no resistance mutations developed. NA808 prevented replication of all HCV genotypes tested in mice with humanized livers. Intravenous NA808 significantly reduced viral load in the mice and had synergistic effects with pegylated interferon alfa-2a and HCV polymerase and protease inhibitors. Conclusions The SPT inhibitor NA808 prevents replication of HCV genotypes 1a, 1b, 2a, 3a, and 4a in cultured hepatocytes and in mice with humanized livers. It might be developed for treatment of HCV infection or used in combination with pegylated interferon alfa-2a or HCV polymerase or protease inhibitors. © 2013 by the AGA Institute.
Ogawa K.,Chugai Pharmaceuticals Co. |
Kato M.,Chugai Pharmaceuticals Co. |
Houjo T.,Chugai Research Institute for Medical Science Inc. |
Ishigai M.,Chugai Pharmaceuticals Co.
Xenobiotica | Year: 2013
1. Focusing on the genetic similarity of CYP3A subfamily enzymes (CYP3A4 and CYP3A5) between monkeys and humans, we have attempted to provide a single-species approach to predicting human hepatic clearance (CLh) of CYP3A4 substrates using pharmacokinetic parameters in cynomolgus monkeys following intravenous administrations. 2. Hepatic intrinsic clearance (CL int,h) of six CYP3A4 substrates (alprazolam, clonazepam, diltiazem, midazolam, nifedipine, and quinidine), covering a wide range of clearance, in monkeys correlated well with that cited in literature for humans (R = 0.90) with a simple equation of Y = 0.165X (Y: human CLint,h, X: monkey CL int,h, represented in mL/min/kg). 3. To verify the predictability of human CLint,h, monkey CLint,h of a test set of CYP3A4 substrates cited in literature (dexamethasone, nifedipine, midazolam, quinidine, tacrolimus, and verapamil) was applied to the equation and human CL int,h was calculated. The human CLint,h of all the substrates was predicted within 3-fold error (fold error: 0.35-2.77). 4. The predictability of human CLh by our method was superior to common in vivo prediction methods (allometry and liver blood flow method). These results suggest that human hepatic clearance of CYP3A4 substrates can be predicted by applying cynomolgus monkey CLint,h obtained following intravenous administrations in each laboratory to the simple equation. © 2013 Informa UK, Ltd.
Sakamoto H.,Chugai Pharmaceutical Co. |
Tsukaguchi T.,Chugai Pharmaceutical Co. |
Hiroshima S.,Chugai Research Institute for Medical Science Inc. |
Kodama T.,Chugai Pharmaceutical Co. |
And 6 more authors.
Cancer Cell | Year: 2011
Anaplastic lymphoma kinase (ALK) is a tyrosine kinase that is constitutively activated in certain cancers, following gene alterations such as chromosomal translocation, amplification, or point mutation. Here, we identified CH5424802, a potent, selective, and orally available ALK inhibitor with a unique chemical scaffold, showing preferential antitumor activity against cancers with gene alterations of ALK, such as nonsmall cell lung cancer (NSCLC) cells expressing EML4-ALK fusion and anaplastic large-cell lymphoma (ALCL) cells expressing NPM-ALK fusion in vitro and in vivo. CH5424802 inhibited ALK L1196M, which corresponds to the gatekeeper mutation conferring common resistance to kinase inhibitors, and blocked EML4-ALK L1196M-driven cell growth. Our results support the potential for clinical evaluation of CH5424802 for the treatment of patients with ALK-driven tumors. © 2011 Elsevier Inc.
Suzuki M.,Chugai Pharmaceutical Co. |
Honda K.,Chugai Pharmaceutical Co. |
Fukazawa M.,Chugai Pharmaceutical Co. |
Ozawa K.,Chugai Pharmaceutical Co. |
And 10 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2012
Sodium/glucose cotransporter 2 (SGLT2) is the predominant mediator of renal glucose reabsorption and is an emerging molecular target for the treatment of diabetes. We identified a novel potent and selective SGLT2 inhibitor, tofogliflozin (CSG452), and examined its efficacy and pharmacological properties as an antidiabetic drug. Tofogliflozin competitively inhibited SGLT2 in cells overexpressing SGLT2, and K i values for human, rat, and mouse SGLT2 inhibition were 2.9, 14.9, and 6.4 nM, respectively. The selectivity of tofogliflozin toward human SGLT2 versus human SGLT1, SGLT6, and sodium/myoinositol transporter 1 was the highest among the tested SGLT2 inhibitors under clinical development. Furthermore, no interaction with tofogliflozin was observed in any of a battery of tests examining glucose-related physiological processes, such as glucose uptake, glucose oxidation, glycogen synthesis, hepatic glucose production, glucose-stimulated insulin secretion, and glucosidase reactions. A single oral gavage of tofogliflozin increased renal glucose clearance and lowered the blood glucose level in Zucker diabetic fatty rats. Tofogliflozin also improved postprandial glucose excursion in a meal tolerance test with GK rats. In db/db mice, 4-week tofogliflozin treatment reduced glycated hemoglobin and improved glucose tolerance in the oral glucose tolerance test 4 days after the final administration. No blood glucose reduction was observed in normoglycemic SD rats treated with tofogliflozin. These findings demonstrate that tofogliflozin inhibits SGLT2 in a specific manner, lowers blood glucose levels by increasing renal glucose clearance, and improves pathological conditions of type 2 diabetes with a low hypoglycemic potential. Copyright © 2012 by The American Society for Pharmacology and Experimental Therapeutics.
Suzuki M.,Chugai Pharmaceutical Co. |
Hiramatsu M.,Chugai Research Institute for Medical Science Inc. |
Fukazawa M.,Chugai Pharmaceutical Co. |
Matsumoto M.,Chugai Research Institute for Medical Science Inc. |
And 3 more authors.
Diabetes, Obesity and Metabolism | Year: 2014
Aims: Urinary tract infection (UTI) is a common clinical problem in diabetic patients; however, the relationship between UTI and glucosuria remains uncertain. To investigate the relationship, we examined the effect of glucosuria induced by sodium glucose cotransporter 2 (SGLT2) inhibitors on the progression of UTI in mice. Methods: From 1day before transurethral inoculation with Candida albicans, female mice were treated orally once a day with an SGLT2 inhibitor in different treatment regimens: (i) dapagliflozin at 10mg/kg for 2, 3 or 7days, (ii) dapagliflozin at 0.1, 1 or 10mg/kg for 3days and (iii) dapagliflozin, canagliflozin or tofogliflozin at 10mg/kg for 3days. To evaluate the ascending UTI, the kidneys were removed 6days after the inoculation, and the number of viable C. albicans cells in kidney was measured as colony-forming units (CFU). Results: In mice treated with dapagliflozin, the number of C. albicans CFU in kidney increased in accordance with both treatment duration and dose. The number of CFU significantly increased when mice were treated with 10mg/kg dapagliflozin or canagliflozin but not tofogliflozin. With dapagliflozin and canagliflozin, urine glucose concentration (UGC) significantly increased up to 24h after drug administration; with tofogliflozin, UGC significantly increased only up to 12h after drug administration. Conclusions: Our data indicate that increased susceptibility to UTI is associated with a persistent increase in UGC. © 2014 John Wiley & Sons Ltd.
Yamaguchi K.,Chugai Pharmaceutical Co. |
Kato M.,Chugai Pharmaceutical Co. |
Suzuki M.,Chugai Pharmaceutical Co. |
Hagita H.,Chugai Research Institute for Medical Science Inc. |
And 5 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2013
To evaluate the relationship between the in vitro and in vivo potency of sodium-glucose cotransporter (SGLT) inhibitors, a pharmacokinetic and pharmacodynamic (PK-PD) study was performed using normal rats. A highly selective SGLT2 inhibitor, tofogliflozin, and four other inhibitors with different in vitro inhibition potency to SGLT2 and selectivity toward SGLT2, versus SGLT1 were used as test compounds, and the time courses for urinary glucose excretion (UGE) and the plasma glucose and compound concentrations were monitored after administration of the compounds. A PK-PD analysis of the UGE caused by SGLT inhibition was performed on the basis of a nonlinear parallel tube model that took into consideration the consecutive reabsorption by different glucose transport properties of SGLT2 and SGLT1. The model adequately captured the time course of cumulative UGE caused by SGLT inhibition; then, the in vivo inhibition constants (Ki) of inhibitors for both SGLT1 and SGLT2 were estimated. The in vivo selectivity toward SGLT2 showed a good correlation with the in vitro data (r 5 0.985; P < 0.05), with in vivo K i values for SGLT2 in the range of 0.3-3.4-fold the in vitro data. This suggests that in vitro inhibition potency to both SGLT2 and SGLT1 is reflected in vivo. Furthermore, the complementary role of SGLT1 to SGLT2 and how selectivity toward SGLT2 affects the inhibitory potency for renal glucose reabsorption were discussed using the PK-PD model. Copyright © 2013 by The American Society for Pharmacology and Experimental Therapeutics.
Saikusa K.,Yokohama City University |
Fuchigami S.,Yokohama City University |
Takahashi K.,Yokohama City University |
Takahashi K.,Chugai Research Institute for Medical Science Inc. |
And 8 more authors.
Analytical Chemistry | Year: 2013
The minimum structural unit of chromatin is the nucleosome core particle (NCP), consisting of 146 bp of DNA wrapped around a histone octamer, which itself contains two H2A/H2B dimers and one (H3/H4)2 tetramer. These multimers possess functionally important tail regions that are intrinsically disordered. In order to elucidate the mechanisms behind NCP assembly and disassembly processes, which are highly related to gene expression, structural characterization of the H2A/H2B dimer and (H3/H4)2 tetramer will be of importance. In the present study, human histone multimers with disordered tail regions were characterized by electrospray ionization (ESI) ion mobility-mass spectrometry (IM-MS) and molecular dynamics (MD) simulation. Experimentally obtained arrival times of these histone multimer ions showed rather wide distributions, implying that multiple conformers exist for each histone multimer in the gas phase. To examine their structures, MD simulations of the histone multimers were performed first in solution and then in vacuo at four temperatures, resulting in a variety of histone multimer structures. Theoretical collision cross-section (CCS) values calculated for the simulated structures revealed that structural models with smaller CCS values had more compact tail regions than those with larger CCS values. This implied that variation of the CCS values of the histone multimers were primarily due to the random behaviors of the tail regions in the gas phase. The combination of IM-MS and MD simulation enabled clear and comprehensive characterization of the gas-phase structures of histone multimers containing disordered tails. © 2013 American Chemical Society.
Kawase Y.,Chugai Research Institute for Medical Science Inc |
Suzuki H.,Obihiro University of Agriculture and Veterinary Medicine
Journal of Reproduction and Development | Year: 2011
This review describes the study of freeze-dried mouse sperm for practical application in preserving and transporting genetic resources. Freeze-dried sperm can be used to preserve and transport genetic resources; however, there still remain many areas which need to be studied. In particular, it is essential to assure long-term preservation over several decades or centuries. Recently, the theory of accelerated degradation kinetics to freeze-dried mouse sperm has been applied, and found that long-term preservation by conventional methods requires temperatures lower than -80 C. When the relationship between the pressure at primary drying and the preservation potential of freezedried mouse sperm was examined, a pressure of 0.37 mbar at primary drying significantly improved the developmental rate to the blastocyst stage. In addition, it has been shown that freeze-dried sperm stored at -80 C with and without transportation can retain their ability to generate viable offspring after storage for up to 2 years. Sperm chromatin structure assay (SCSA) was applied to mouse sperm freeze-dried under several conditions and compared the results with the embryonic developmental rates of freeze-dried sperm after intracytoplasmic sperm injection (ICSI) and with comet assay results. Furthermore, SCSA might be useful for estimation of developmental potential of fertilized eggs derived from ICSI using freeze-dried sperm in mice. © 2011 by the Society for Reproduction and Development.
Kato A.,Chugai Pharmaceutical Co. |
Fujii E.,Chugai Pharmaceutical Co. |
Watanabe T.,Chugai Research Institute for Medical Science Inc. |
Takashima Y.,Chugai Pharmaceutical Co. |
And 3 more authors.
Journal of Dermatological Science | Year: 2014
Background: To understand the clinical segments of IL-31 signaling blockade therapy in pruritus of atopic dermatitis (AD), direct detection of the target proteins in the diseased tissues will provide crucial information. There is a lack of direct evidence concerning the cellular origin of IL-31 in AD skins, and data on the expression of IL-31RA in AD are inconsistent. Also, there is no available information regarding IL-31RA protein expression in human dorsal root ganglia (DRG), which mediates the sensation of itch and is the long-suspected source of the protein. Objective: We sought to obtain direct evidence concerning the distribution of IL-31- and IL-31RA-protein expressing cells and their characteristics in AD skin samples and in human DRG. Methods: IL-31 was detected immunohistochemically in AD skins, and representative sections were double stained with IL-31 and several immune-markers. IL-31RA was stained immunohistochemically in AD skins and normal human DRG, and representative AD skins were double stained with IL-31RA and PGP9.5 (a nerve marker). Results: IL-31-positive cells were observed as mononuclear infiltrating cells and as CD11b co-expressing cells in severe AD samples. As for IL-31RA, positive reactions were detected in keratinocytes and nerve fibers in the dermis of AD and in the neurons of normal DRG. Conclusion: The detection of IL-31 in infiltrating cells of severe AD skin and of IL-31RA in nerve fibers of AD dermis and normal DRG indicates IL-31 signaling may be a contributing factor in the persistence and exacerbation of AD skin lesions. © 2014 Japanese Society for Investigative Dermatology.
PubMed | Chugai Research Institute for Medical Science Inc.
Type: Journal Article | Journal: The Journal of veterinary medical science | Year: 2016
Currently, from the viewpoint of animal welfare, anesthesia or analgesia is required during experimental procedures in animals that are likely to cause pain. A part of these anesthetics have been reported to influence a blood biochemical level. It is important for us to understand the effect of the anesthetic on blood biochemistry when we choose the anesthetic agent to be used in experiments. In this study, we examined the blood biochemical changes in mice after administration of a new mixture of three anesthetic agents -medetomidine / midazolam / butorphanol (MMB). We subcutaneously administered two dose combinations of MMB (0.45 / 6 / 7.5 and 0.9 / 12 / 15 mg/kg) in mice, followed by administration of atipamezole, for reversal of anesthetic effects, after 1 hr. Thereafter, blood biochemistry was assessed at 1, 4 and 24 hr after MMB administration. We observed that MMB administration caused a transient increase in blood sugar, inorganic phosphorus, potassium and creatine kinase levels. These, however, returned to the reference range 24 hr after MMB administration. In conclusion, MMB changes the levels of some blood biochemical parameters, but not to an extent that would threaten health. However, when using laboratory animals, this effect of MMB may influence the experimental results, depending on the experimental content. Hence, the choice of anesthetic agents used in laboratory animals should be based on detailed knowledge of their pharmacological effects.