Tokushima Research Institute

Tokushima-shi, Japan

Tokushima Research Institute

Tokushima-shi, Japan
Time filter
Source Type

Horiuchi T.,Tohoku University | Sakata N.,Tohoku University | Narumi Y.,Tohoku University | Kimura T.,Tohoku University | And 9 more authors.
Journal of Biological Chemistry | Year: 2017

Metformin is the first-line drug in the treatment of type 2 diabetes. In addition to its hypoglycemic effect, metformin has an anti-inflammatory function, but the precise mechanism promoting this activity remains unclear. High mobility group box 1 (HMGB1) is an alarmin that is released from necrotic cells and induces inflammatory responses by its cytokine-like activity and is, therefore, a target of anti-inflammatory therapies. Here we identified HMGB1 as a novel metformin-binding protein by affinity purification using a biotinylated metformin analogue. Metformin directly bound to the C-terminal acidic tail of HMGB1. Both in vitro and in vivo, metformin inhibited inflammatory responses induced by full-length HMGB1 but not by HMGB1 lacking the acidic tail. In an acetaminophen-induced acute liver injury model in which HMGB1 released from injured cells exacerbates the initial injury, metformin effectively reduced liver injury and had no additional inhibitory effects when the extracellular HMGB1 was blocked by anti-HMGB1-neutralizing antibody. In summary, we report for the first time that metformin suppresses inflammation by inhibiting the extracellular activity of HMGB1. Because HMGB1 plays a major role in inflammation, our results suggest possible new ways to manage HMGB1-induced inflammation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Kobayashi S.,Nihon University | Ueda Y.,Kurashiki Central Hospital | Nannya Y.,University of Tokyo | Shibayama H.,Osaka University | And 17 more authors.
Cancer Biomarkers | Year: 2016

BACKGROUND: This present study was designed to follow up 82 patients among 115 MDS patients registered in study ODK- 0801 for 5 years, to analyze the relationship between the WT1 mRNA expression level and prognosis. OBJECTIVE: This study aimed to investigate the clinical utility of WT1 mRNA expression levels. METHODS: After study ODK-0801, we investigated the conditions of the same patients once a year, including any clinical and laboratory findings supporting the diagnosis, and treatment among the living patients. RESULTS: When we assessed the survival time of 82 MDS patients by WT1 mRNA expression level, there were significant differences between the < 500 and ≥ 104 copies/μg RNA groups and between the 500-104 and ≥ 104 copies/μg RNA groups for BM levels (p < 0.01). Examination of the time of freedom from acute myeloid leukemia (AML) transformation indicated that a high WT1 mRNA expression level (> 104 copies/μg RNA) was a strong prognostic factor for a short time to AML transformation. CONCLUSION: The results indicate that the tumorigenesis of MDS is likely to originate at the stem cell level, suggesting that the WT1 mRNA level measurement in the BM is an effective prognostic marker in patients with MDS. © 2016 - IOS Press and the authors.

Shimada Y.,Otsuka Pharmaceutical Factory Inc. | Yasuda S.,Otsuka Pharmaceutical Factory Inc. | Takahashi M.,Otsuka Pharmaceutical Factory Inc. | Hayashi T.,Otsuka Pharmaceutical Factory Inc. | And 5 more authors.
Applied and Environmental Microbiology | Year: 2010

Equol is a metabolite produced from daidzein by enteric microflora, and it has attracted a great deal of attention because of its protective or ameliorative ability against several sex hormone-dependent diseases (e.g., menopausal disorder and lower bone density), which is more potent than that of other isoflavonoids. We purified a novel NADP(H)-dependent daidzein reductase (L-DZNR) from Lactococcus strain 20-92 (Lactococcus 20-92; S. Uchiyama, T. Ueno, and T. Suzuki, international patent WO2005/000042) that is involved in the metabolism of soy isoflavones and equol production and converts daidzein to dihydrodaidzein. Partial amino acid sequences were determined from purified L-DZNR, and the gene encoding L-DZNR was cloned. The nucleotide sequence of this gene consists of an open reading frame of 1,935 nucleotides, and the deduced amino acid sequence consists of 644 amino acids. L-DZNR contains two cofactor binding motifs and an 4Fe-4S cluster. It was further suggested that L-DZNR was an NAD(H)/NADP(H): flavin oxidoreductase belonging to the old yellow enzyme (OYE) family. Recombinant histidine-tagged L-DZNR was expressed in Escherichia coli. The recombinant protein converted daidzein to (S)-dihydrodaidzein with enantioselectivity. This is the first report of the isolation of an enzyme related to daidzein metabolism and equol production in enteric bacteria. Copyright © 2010, American Society for Microbiology.

Shibamori M.,Otsuka Pharmaceutical Factory Inc. | Sato M.,Otsuka Pharmaceutical Factory Inc. | Uematsu N.,Otsuka Pharmaceutical Factory Inc. | Nakashima T.,Otsuka Pharmaceutical Factory Inc. | And 5 more authors.
Journal of Pharmacological Sciences | Year: 2015

Recent studies have shown that rebamipide, which suppresses reactive oxygen species, prevents chemoradiotherapy-induced oral mucositis in patients with head and neck cancers. However, anticancer action of radiotherapy and chemotherapy is believed to be partially associated with generation of reactive oxygen species. The aim of this study was to determine whether rebamipide interferes with the antitumor action of radiotherapy and chemotherapy. The effect of rebamipide on tumor cell growth was investigated using a human oral squamous carcinoma cell line, HSC-2, in vitro and in vivo. Rebamipide showed no significant effect on cell or tumor growth in HSC-2 tumor-bearing nude mice. Influences of rebamipide on the antitumor action of radiotherapy and of chemotherapy with cisplatin or docetaxel were investigated using the same animal model. In radiotherapy, the tumor was treated with 2.5 Gy of X-rays for 5 days, and rebamipide (300 mg/kg p.o.) was administered during irradiation periods. In chemotherapy, tumor-bearing mice were treated once with cisplatin (8 mg/kg, i.v.) or docetaxel (15 mg/kg i.v.) and rebamipide (300 mg/kg p.o.) was administered for 5 days following the antitumor drug treatment. Rebamipide did not interfere with the antitumor action of radiotherapy and chemotherapy. © 2015 The Authors.

Yamamura Y.,Tokushima Research Institute | Koyama N.,Tokushima Research Institute | Umehara K.,Tokushima Research Institute
Xenobiotica | Year: 2015

1. Chlorzoxazone (CLZ) is currently being used as a marker substrate in vitro/vivo studies to quantify cytochrome P450 2E1 (CYP2E1) activity in humans. Although in CLZ 6-hydroxylation several CYPs are responsible, previous studies have presented the monophasicity of the reaction in human liver microsomes (HLMs). Furthermore, the Km values of CYP2E1 for the 6-hydroxylation in HLMs were reported to be lower than those of its recombinant enzymes. 2. This study aimed to provide the comprehensive Km values for the CLZ 6-hydroxylation in HLMs using CYP antibodies. The Eadie-Hofstee plots revealed a biphasic profile and indicate that the reaction was mainly mediated by CYP1A2 as well as CYP2E1. The formation of 6-hydroxychlorzoxazone was more specific for CYP2E1 activity at higher substrate concentration in HLMs. 3. Moreover, KOH as a vehicle for substrate or sucrose included in HLMs preparation had some effect on the activity of CLZ 6-hydroxylase. These constituents seemed to be casually related to the apparent monophasic kinetics and variability in Km values for the CLZ 6-hydroxylation in HLMs. 4. The Km of CYP1A2 and CYP2E1 in HLMs was 3.8 μmol/L and 410 μmol/L, respectively, and the value of CYP2E1 was close to that of recombinant CYP2E1. © 2014 Informa UK Ltd.

Yoda N.,Tokushima Research Institute
Xenobiotica; the fate of foreign compounds in biological systems | Year: 2012

Cynomolgus monkeys are widely used to predict human pharmacokinetic and/or toxic profiles in the drug developmental stage. Characterization of cynomolgus monkey P450s such as the mRNA expression level, substrate specificity, and inhibitor selectivity were conducted to provide helpful information in designing monkey in vivo studies and monkey-to-human extrapolation. The expression levels of 12 monkey P450 mRNAs, which are considered to be important P450 subfamilies in drug metabolism, were investigated in the liver, small intestine (duodenum, jejunum, and ileum), and colon of individual monkeys. 3. In vitro activities and intrinsic clearance values were determined in monkey intestinal and liver microsomes (MIM and MLM, respectively) using nine typical oxidative reactions for human P450s. Paclitaxel 6α-hydroxylation, diclofenac 4′-hydroxylation, and S-mephenytoin 4′-hydroxylation showed low activities in MIM and MLM. IC50 values of eight selective inhibitors of human P450s were determined in MIM and MLM. Inhibitory effects of furafylline and sulfaphenazole were weak in monkeys on phenacetin O-deethylation and diclofenac 4′-hydroxylation, respectively. These results show profiles of monkey P450s in both the intestine and liver in detail and contribute to a better understanding of the species difference in substrate specificity and inhibitor selectivity between cynomolgus monkeys and humans.

Loading Tokushima Research Institute collaborators
Loading Tokushima Research Institute collaborators