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Featured researches published by Tomokatsu Iwamura.


Journal of Pharmacology and Experimental Therapeutics | 2014

HIS-388, a Novel Orally Active and Long-Acting 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor, Ameliorates Insulin Sensitivity and Glucose Intolerance in Diet-Induced Obesity and Nongenetic Type 2 Diabetic Murine Models

Seiji Okazaki; Takehiro Takahashi; Tomokatsu Iwamura; Junko Nakaki; Yumiko Sekiya; Mai Yagi; Hiroki Kumagai; Mikiya Sato; Satoshi Sakami; Aiko Nitta; Koji Kawai; Mie Kainoh

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is considered a potential therapeutic target in the treatment of type 2 diabetes mellitus. In this study, we investigated the pharmacological properties of HIS-388 (N-[(1R,2s,3S,5s,7s)-5-hydroxyadamantan-2-yl]-3-(pyridin-2-yl) isoxazole-4-carboxamide), a newly synthesized 11β-HSD1 inhibitor, using several mouse models. In cortisone pellet–implanted mice in which hypercortisolism and hyperinsulinemia occur, single administration of HIS-388 exhibited potent and prolonged suppression of plasma cortisol and lowered plasma insulin levels. These effects were more potent than those achieved using the same dose of other 11β-HSD1 inhibitors (carbenoxolone and compound 544 [3-[(1s,3s)-adamantan-1-yl]-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepine]), indicating that HIS-388 potently and continuously suppresses 11β-HSD1 enzyme activity in vivo. In diet-induced obese mice, HIS-388 significantly decreased fasting blood glucose, plasma insulin concentration, and homeostasis model assessment–insulin resistance score, and ameliorated insulin sensitivity. In addition, HIS-388 significantly reduced body weight and suppressed the elevation of blood glucose during the pyruvate tolerance test. In nongenetic type 2 diabetic mice with disease induced by a high-fat diet and low-dose streptozotocin, HIS-388 also significantly decreased postprandial blood glucose and plasma insulin levels and improved glucose intolerance. The effects of HIS-388 on glucose metabolism were indistinguishable from those of an insulin sensitizer, pioglitazone. Our results suggest that HIS-388 is a potent agent against type 2 diabetes. Moreover, amelioration of diabetic symptoms by HIS-388 was at least in part attributable to an antiobesity effect or improvement of hepatic insulin resistance. Therefore, potent and long-lasting inhibition of 11β-HSD1 enzyme activity may be an effective approach for the treatment of type 2 diabetes and obesity-associated disease.


Journal of Pharmacology and Experimental Therapeutics | 2014

HIS-388, a novel orally active and long-acting 11β-HSD1 inhibitor, ameliorates insulin sensitivity and glucose intolerance in diet-induced obesity and non-genetic type 2 diabetic murine models

Seiji Okazaki; Takehiro Takahashi; Tomokatsu Iwamura; Junko Nakaki; Yumiko Sekiya; Mai Yagi; Hiroki Kumagai; Mikiya Sato; Satoshi Sakami; Aiko Nitta; Koji Kawai; Mie Kainoh

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is considered a potential therapeutic target in the treatment of type 2 diabetes mellitus. In this study, we investigated the pharmacological properties of HIS-388 (N-[(1R,2s,3S,5s,7s)-5-hydroxyadamantan-2-yl]-3-(pyridin-2-yl) isoxazole-4-carboxamide), a newly synthesized 11β-HSD1 inhibitor, using several mouse models. In cortisone pellet–implanted mice in which hypercortisolism and hyperinsulinemia occur, single administration of HIS-388 exhibited potent and prolonged suppression of plasma cortisol and lowered plasma insulin levels. These effects were more potent than those achieved using the same dose of other 11β-HSD1 inhibitors (carbenoxolone and compound 544 [3-[(1s,3s)-adamantan-1-yl]-6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepine]), indicating that HIS-388 potently and continuously suppresses 11β-HSD1 enzyme activity in vivo. In diet-induced obese mice, HIS-388 significantly decreased fasting blood glucose, plasma insulin concentration, and homeostasis model assessment–insulin resistance score, and ameliorated insulin sensitivity. In addition, HIS-388 significantly reduced body weight and suppressed the elevation of blood glucose during the pyruvate tolerance test. In nongenetic type 2 diabetic mice with disease induced by a high-fat diet and low-dose streptozotocin, HIS-388 also significantly decreased postprandial blood glucose and plasma insulin levels and improved glucose intolerance. The effects of HIS-388 on glucose metabolism were indistinguishable from those of an insulin sensitizer, pioglitazone. Our results suggest that HIS-388 is a potent agent against type 2 diabetes. Moreover, amelioration of diabetic symptoms by HIS-388 was at least in part attributable to an antiobesity effect or improvement of hepatic insulin resistance. Therefore, potent and long-lasting inhibition of 11β-HSD1 enzyme activity may be an effective approach for the treatment of type 2 diabetes and obesity-associated disease.


Cancer Science | 2017

Novel pegylated interferon-β as strong suppressor of the malignant ascites in a peritoneal metastasis model of human cancer

Tomokatsu Iwamura; Hideki Narumi; Tomohiko Suzuki; Hideyuki Yanai; Katsuyuki Mori; Koji Yamashita; Yoshiaki Tsushima; Tomomi Asano; Akiko Izawa; Shinobu Momen; Kazumi Nishimura; Hiromi Tsuchiyama; Masashi Uchida; Yuji Yamashita; Kiyoshi Okano; Tadatsugu Taniguchi

Malignant ascites manifests as an end‐stage event during the progression of a number of cancers and lacks a generally accepted standard therapy. Interferon‐β (IFN‐β) has been used to treat several cancer indications; however, little is known about the efficacy of IFN‐β on malignant ascites. In the present study, we report on the development of a novel, engineered form of human and murine IFN‐β, each conjugated with a polyethylene glycol molecule (PEG‐hIFN‐β and PEG‐mIFN‐β, respectively). We provide evidence that these IFN‐β molecules retain anti‐viral potency comparable to unmodified IFN‐β in vitro and manifested improved pharmacokinetics in vivo. Interestingly, PEG‐mIFN‐β significantly inhibited the accumulation of ascites fluid and vascular permeability of the peritoneal membrane in models of ovarian cancer and gastric cancer cell xenograft mice. We further show that PEG‐hIFN‐β directly suppresses VEGF165‐induced hyperpermeability in a monolayer of human vascular endothelial cells and that PEG‐mIFN‐β enhanced gene expression for a number of cell adhesion related molecules in mouse vascular endothelial cells. Taken together, these findings unveil a hitherto unrecognized potential of IFN‐β in maintaining vascular integrity, and provide proof‐of‐mechanism for a novel and long‐acting pegylated hIFN‐β for the therapeutic treatment of malignant ascites.


Bioorganic & Medicinal Chemistry Letters | 2013

Discovery of novel 7-membered cyclic amide derivatives that inhibit 11beta-hydroxysteroid dehydrogenase type 1

Shuji Udagawa; Satoshi Sakami; Takahiro Takemura; Mikiya Sato; Takahiro Arai; Aiko Nitta; Takumi Aoki; Koji Kawai; Tomokatsu Iwamura; Seiji Okazaki; Takehiro Takahashi; Mie Kaino

A series of novel 5-trans-hydroxyadamantan-2-yl-5,6,7,8-tetrahydropyrazolo[4,3-c]azepin-4(1H)-ones that inhibit 11beta-hydroxysteroid dehydrogenase type 1 are described. We discovered these 7-membered cyclic amide derivatives by introducing a distinctive linker through pharmacophore analysis of known ligands included in X-ray co-crystal structures. Further optimization using docking studies led to highly potent inhibitors 15b and 27, which furthermore showed the potent efficacy in in vivo studies.


Antimicrobial Agents and Chemotherapy | 2017

Development of a Novel Site-Specific Pegylated Interferon Beta for Antiviral Therapy of Chronic Hepatitis B Virus

Masataka Tsuge; Takuro Uchida; Nobuhiko Hiraga; Hiromi Kan; Grace Naswa Makokha; Hiromi Abe-Chayama; Daiki Miki; Michio Imamura; Hidenori Ochi; C. Nelson Hayes; Rieko Shimozono; Tomokatsu Iwamura; Hideki Narumi; Tomohiko Suzuki; Mie Kainoh; Tadatsugu Taniguchi; Kazuaki Chayama

ABSTRACT Although nucleot(s)ide analogues and pegylated interferon alpha 2a (PEG-IFN-α2a) can suppress hepatitis B virus (HBV) replication, it is difficult to achieve complete HBV elimination from hepatocytes. A novel site-specific pegylated recombinant human IFN-β (TRK-560) was recently developed. In the present study, we evaluated the antiviral effects of TRK-560 on HBV replication in vitro and in vivo. In vitro and in vivo HBV replication models were treated with antivirals including TRK-560, and changes in HBV markers were evaluated. To analyze antiviral mechanisms, cDNA microarray analysis and an enzyme-linked immunoassay (ELISA) were performed. TRK-560 significantly suppressed the production of intracellular HBV replication intermediates and extracellular HBV surface antigen (HBsAg) (P < 0.001 and P < 0.001, respectively), and the antiviral effects of TRK-560 were enhanced in combination with nucleot(s)ide analogues, such as entecavir and tenofovir disoproxil fumarate. The reduction in HBV DNA levels by TRK-560 treatment was significantly higher than that by PEG-IFN-α2a treatment both in vitro and in vivo (P = 0.004 and P = 0.046, respectively), and intracellular HBV covalently closed circular DNA (cccDNA) reduction by TRK-560 treatment was also significantly higher than that by PEG-IFN-α2a treatment in vivo (P = 0.0495). cDNA microarrays and ELISA for CXCL10 production revealed significant differences between TRK-560 and PEG-IFN-α2a in the induction potency of interferon-stimulated genes. TRK-560 shows a stronger antiviral potency via higher induction of interferon-stimulated genes and stronger stimulation of immune cell chemotaxis than PEG-IFN-α2a. As HBsAg loss and HBV cccDNA eradication are important clinical goals, these results suggest a potential role for TRK-560 in the development of more effective treatment for chronic hepatitis B infection.


Archive | 2007

IMMUNOSTIMULATORY OLIGONUCLEOTIDE AND PHARMACEUTICAL APPLICATION THEREOF

Tomokatsu Iwamura; Hideki Narumi; Hajime Masumoto; Akihito Kaneda; Akiko Soneda; Shizuo Akira


Archive | 2007

Immunostimulatory oligonucleotides and use thereof in pharmaceuticals

Tomokatsu Iwamura; Hideki Narumi; Hajime Masumoto; Akihito Kaneda; Akiko Soneda; Shizuo Akira


The Molecular Biology Society of Japan | 2016

Identification and characterization of human monoclonal anti-E2 antibodies cloned from chronic hepatitis C patient

Hiroshi Yokokawa; Midori Shinohara; Noriko Nakamura; Tomokatsu Iwamura; Tomohiko Suzuki; Takaji Wakita


Archive | 2007

Oligonucleotides immunostimulateurs et utilisation de ceux-ci dans des produits pharmaceutiques

Tomokatsu Iwamura; Hideki Narumi; Hajime Masumoto; Akihito Kaneda; Akiko Soneda; Shizuo Akira


Archive | 2007

Immunostimulatory oligonucleotide and pharmaceutical use thereof

Hajime Masumoto; Akihito Kaneda; Tomokatsu Iwamura; Hideki Narumi; Akiko Soneda; Shizuo Akira

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