65 results on '"Iwatani, M."'
Search Results
2. T/B scaling without quasiparticle mass divergence: YbCo2Ge4
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Sakai, A., Kitagawa, K., Matsubayashi, K., Iwatani, M., and Gegenwart, P.
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Condensed Matter - Strongly Correlated Electrons - Abstract
YbCo$_2$Ge$_4$ is a clean paramagnetic Kondo lattice which displays non-Fermi liquid behavior. We report a detailed investigation of the specific heat, magnetic Gr\"uneisen parameter ($\Gamma_{\rm mag}$) and temperature derivative of the magnetization ($M$) on a high-quality single crystal at temperatures down to $0.1$~K and magnetic fields up to 7~T. $\Gamma_{\rm mag}$ and $dM/dT$ display a divergence upon cooling and obey $T/B$ scaling. Similar behavior has previously been found in several other Yb-based Kondo lattices and related to a zero-field quantum critical point without fine tuning of pressure or composition. However, in the approach of $B\rightarrow 0$ the electronic heat capacity coefficient of YbCo$_2$Ge$_4$ saturates at low $T$, excluding ferromagnetic quantum criticality. This indicates that $T/B$ scaling is insufficient to prove a zero-field quantum critical point., Comment: 6 pages, 6 figures (including supplemental material)
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- 2016
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3. Quantum Criticality Based on Large Ising Spins: YbCo$_2$Ge$_4$ with New 1-2-4 Structure Type
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Kitagawa, K., Kishimoto, Y., Iwatani, M., Nishioka, T., Matsumura, M., Matsubayashi, K., Uwatoko, Y., Maki, S., Yamaura, J-I., Hattori, T., and Ishida, K.
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Condensed Matter - Strongly Correlated Electrons - Abstract
We present a new type of quantum critical material YbCo$_2$Ge$_4$, having the largest quantum-critical pseudospin size ever. The YbCo$_2$Ge$_4$-type structure is new, forms in the orthorhombic $Cmcm$ system, and is related to the well-known ThCr$_2$Si$_2$ structure. Heavy rare earth (Tm,Yb,Lu, or Y) members are also possible to be grown. YbCo$_2$Ge$_4$ possesses the Ising-type ground-state doublet, namely the simplest ones of uniaxially up or down, $|\pm \sim 7/2\rangle$. It is clearly manifested through comprehensive resistivity, magnetization, specific heat, and NQR/NMR experiments. Large pseudospin state usually tends to order in simple magnetisms, or hard to be screened by Kondo effect. Therefore, the discovery of the quantum criticality of the fluctuating large spins opens a new door to new-material search and theoretical studies., Comment: 8 pages, 5 figures, 1 table, including supplementary material
- Published
- 2014
4. Superconducting properties of [Nb.sub.3]Sn wire fabricated by diffusion reaction between Ag-Sn-Mg alloy and Nb
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Iwatani, M., Inoue, K., Takeuchi, T., and Kiyoshi, T.
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Magnesium -- Electric properties ,Magnesium -- Magnetic properties ,Niobium alloys -- Magnetic properties ,Niobium alloys -- Electric properties ,Silver alloys -- Magnetic properties ,Silver alloys -- Electric properties ,Tin alloys -- Magnetic properties ,Tin alloys -- Electric properties ,Business ,Electronics ,Electronics and electrical industries - Published
- 2009
5. Crystallographic analysis of amorphization caused by ion irradiation
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Nakagawa, S.T., Iwatani, M., Ono, T., Hada, Y., and Betz, G.
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- 2003
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6. Development of a Thermographic Skin Blood Flowmetry System
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Miyake, H., Fujimasa, I., Iwatani, M., Atsumi, K., Ring, E. Francis J., editor, and Phillips, Barbara, editor
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- 1984
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7. Structure of Focal Adhesion Kinase catalytic domain in complex with novel allosteric inhibitor
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Iwatani, M., primary, Iwata, H., additional, Okabe, A., additional, Skene, R.J., additional, Tomita, N., additional, Hayashi, Y., additional, Aramaki, Y., additional, Hosfield, D.J., additional, Hori, A., additional, Baba, A., additional, and Miki, H., additional
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- 2012
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8. SUPERCONDUCTIVITY AND MICROSTRUCTURE OF V-TI ALLOY MULTIFILAMENT PREPARED BY DIFFUSION REACTION BETWEEN CONSTITUENT PURE-METAL SUBELEMENTS
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Takeuchi, T., primary, Takigawa, H., additional, Banno, N., additional, Nakagawa, M., additional, Iwatani, M., additional, Inoue, K., additional, Hishinuma, Y., additional, Nishimura, A., additional, and Balachandran, U. (Balu), additional
- Published
- 2010
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9. Superconducting Properties of ${\rm Nb}_{3}{\rm Sn}$ Wire Fabricated by Diffusion Reaction Between Ag-Sn-Mg Alloy and Nb
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Iwatani, M., primary, Inoue, K., additional, Takeuchi, T., additional, and Kiyoshi, T., additional
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- 2009
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10. Photoinduced self-assembly to tube, chain, and other aggregate of molybdenum-blue nano-rings
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Yamase, T., primary, Prokop, P., additional, Iwatani, M., additional, and Ishikawa, E., additional
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- 2008
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11. Troglitazone decreases serum uric acid concentrations in Type II diabetic patients and non-diabetics
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Watanabe-Takahashi C, Yasuhiko Iwamoto, Katsumori K, Wasada T, Iwatani M, and Naoyuki Kamatani
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medicine.medical_specialty ,Text mining ,Endocrinology ,business.industry ,Endocrinology, Diabetes and Metabolism ,Internal medicine ,Serum uric acid ,Internal Medicine ,medicine ,Troglitazone ,business ,medicine.drug - Published
- 2000
12. SUPERCONDUCTIVITY AND MICROSTRUCTURE OF V-TI ALLOY MULTIFILAMENT PREPARED BY DIFFUSION REACTION BETWEEN CONSTITUENT PURE-METAL SUBELEMENTS.
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Takeuchi, T., Takigawa, H., Banno, N., Nakagawa, M., Iwatani, M., Inoue, K., Hishinuma, Y., and Nishimura, A.
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WIRE ,SUPERCONDUCTIVITY ,MICROSTRUCTURE ,ELECTRIC conductivity ,ELECTRIC currents - Abstract
We have succeeded in making a superconducting V—Ti alloy multifilament wire using the diffusion reaction between constituent pure-metal subelements, which can omit the melt-and-casting step and may reduce the fabrication cost. A monofilament billet prepared by restacking hexagonal Ti/V composites in a Cu/V tube and a multifilament billet by re-stacking such Cu/V/(Ti/V) composites in a Cu tube were hydrostatically extruded and drawn down to wires. Four kinds of heat treatment were investigated, with respect to mi-crostructure and superconducting properties; (1) an alloying heat treatment (HT
alloy ) which is carried out at the final size (‘fs-HTalloy ’), (2) HTalloy is followed by cold-working (W) down to the final size (‘HTalloy +W1 ’), (3) an precipitation heat treatment (HTprec ) is carried out after the W stage (‘HTalloy +W1 +HTprec ’) and (4) an intermediate HTprec is carried out during the W stage coming after the HTalloy stage (‘HTalloy +W1 +HTprec +W2 ’). The ‘HTalloy +W1 +HTprec +W2 ’ treatment was found to be most effective in enhancing the critical current densities (Jc ), despite the HTprec treatment having slightly degraded the critical temperature (Tc ) and critical magnetic field (Bc2 ). The highest Bc2 was obtained using the ‘HTalloy +W1 ’ treatment, irrespective of the HTalloy temperatures. [ABSTRACT FROM AUTHOR]- Published
- 2010
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13. Troglitazone decreases serum uric acid concentration in type 2 diabetic patients
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Iwatani, M., primary, Wasada, T., additional, Katsumori, K., additional, Watanabe, C., additional, Kamatani, N., additional, and Iwamoto, Y., additional
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- 2000
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14. Tarsal tunnel syndrome caused by tophaceous gout a case report.
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Wakabayashi, Toshiyuki, Irie, Kazunori, Yamanaka, Hisashi, Iwatani, Masako, Inoue, Kazuhiko, Wakabayashi, T, Irie, K, Yamanaka, H, Iwatani, M, and Inoue, K
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- 1998
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15. Plasma amino acid levels in hyperosmolar nonketotic diabetic coma
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Marumo K, Hirata Y, Tasaka Y, Inoue S, and Iwatani M
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medicine.medical_specialty ,Taurine ,Arginine ,Diabetic ketoacidosis ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Phenylalanine ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,medicine ,Humans ,Tyrosine ,Amino Acids ,Glucocorticoids ,Diabetic Coma ,Biochemistry (medical) ,General Medicine ,Ornithine ,Middle Aged ,medicine.disease ,chemistry ,Lactic acidosis ,Hyperglycemic Hyperosmolar Nonketotic Coma ,Diabetic coma - Abstract
The plasma amino acid levels in five patients with hyperosmolar nonketotic diabetic coma and in seven normal subjects were analysed. In the patients with hyperosmolar nonketotic diabetic coma, total amino acids were generally low, especially, the concentrations and the molar ratios of arginine, taurine and serine were significantly low, and ornithine decreased only at the concentration. The level of phenylalanine increased both at the concentration and the molar ratio, and tyrosine did only at the molar ratio. The significance of such changes in the plasma is discussed in relation to diabetic ketoacidosis or lactic acidosis.
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- 1983
16. Plasma Amino Acid Levels in Hyperosmolar Nonketotic Diabetic Coma.
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Tasaka, Y., Iwatani, M., Inoue, S., Marumo, K., and Hirata, Y.
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- 1983
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17. Behavior of water droplets on silicone rubber sheet under AC voltage application
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Mizuno, Y., primary, Iwatani, M., additional, Nagata, M., additional, Naito, K., additional, Kondo, K., additional, and Ito, S., additional
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18. Troglitazone decreases serum uric acid concentrations in Type II diabetic patients and non-diabetics.
- Author
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Iwatani, M., Wasada, T., Katsumori, K., Watanabe-Takahashi, C., Kamatani, N., and Iwamoto, Y.
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DIABETES ,LETTERS to the editor - Abstract
Presents a letter to the editor about a study reporting on the antihyperuricaemic effect of troglitazone in Type II diabetic patients and non-diabetics.
- Published
- 2000
19. Behavior of water droplets on silicone rubber sheet under AC voltage application.
- Author
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Mizuno, Y., Iwatani, M., Nagata, M., Naito, K., Kondo, K., and Ito, S.
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- 1998
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20. The Rubicon-WIPI axis regulates exosome biogenesis during ageing.
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Yanagawa K, Kuma A, Hamasaki M, Kita S, Yamamuro T, Nishino K, Nakamura S, Omori H, Kaminishi T, Oikawa S, Kato Y, Edahiro R, Kawagoe R, Taniguchi T, Tanaka Y, Shima T, Tabata K, Iwatani M, Bekku N, Hanayama R, Okada Y, Akimoto T, Kosako H, Takahashi A, Shimomura I, Sakata Y, and Yoshimori T
- Abstract
Cells release intraluminal vesicles in multivesicular bodies as exosomes to communicate with other cells. Although recent studies suggest an intimate link between exosome biogenesis and autophagy, the detailed mechanism is not fully understood. Here we employed comprehensive RNA interference screening for autophagy-related factors and discovered that Rubicon, a negative regulator of autophagy, is essential for exosome release. Rubicon recruits WIPI2d to endosomes to promote exosome biogenesis. Interactome analysis of WIPI2d identified the ESCRT components that are required for intraluminal vesicle formation. Notably, we found that Rubicon is required for an age-dependent increase of exosome release in mice. In addition, small RNA sequencing of serum exosomes revealed that Rubicon determines the fate of exosomal microRNAs associated with cellular senescence and longevity pathways. Taken together, our current results suggest that the Rubicon-WIPI axis functions as a key regulator of exosome biogenesis and is responsible for age-dependent changes in exosome quantity and quality., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
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- 2024
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21. Design, synthesis, and structure-activity relationship of TAK-418 and its derivatives as a novel series of LSD1 inhibitors with lowered risk of hematological side effects.
- Author
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Hattori Y, Matsumoto S, Morimoto S, Daini M, Toyofuku M, Matsuda S, Baba R, Murakami K, Iwatani M, Oki H, Iwasaki S, Matsumiya K, Tominari Y, Kimura H, and Ito M
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- Animals, Enzyme Inhibitors chemistry, Mice, RNA, Messenger, Structure-Activity Relationship, Histone Demethylases, Lysine metabolism
- Abstract
Lysine-specific demethylase 1 (LSD1) is an enzyme that demethylates methylated histone H3 lysine 4 (H3K4). Inhibition of LSD1 enzyme activity could increase H3K4 methylation levels and treat diseases associated with epigenetic dysregulation. However, known LSD1 inhibitors disrupt the interaction between LSD1 and cofactors such as GFI1B, causing the risk of hematological toxicity, including thrombocytopenia. Starting from a known LSD1 inhibitor (±)1 as a lead compound, a novel series of LSD1 inhibitors that do not induce the expression of GFI1 mRNA, an in vitro surrogate marker of LSD1-GFI1B dissociation, has been designed and synthesized. Initial structure-activity relationship (SAR) studies revealed the structural features key to avoiding GFI1 mRNA induction. Such SAR information enables optimization of LSD1 inhibitors with lowered risk of hematological side effects; TAK-418 ((1R,2R)-2n), the clinical candidate compound found through this optimization, has a hematological safety profile in rodents and humans. We further confirmed that oral administration of TAK-418 at 0.3 and 1 mg/kg for 2 weeks ameliorated memory deficits in mice with NMDA receptor hypofunction, suggesting potential of efficacy in neurodevelopmental disorders. TAK-418 warrants further investigation as a novel class of LSD1 inhibitors with a superior safety profile for the treatment of CNS disorders., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2022
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22. A Flare of Hepatitis C Virus-Associated Cryoglobulinemic Vasculitis After COVID-19.
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Hamazaki K, Umemoto D, Asada T, Iwatani M, Tsuboi K, Oh K, and Konishi H
- Abstract
While undergoing treatment for hepatitis C virus (HCV)-associated cryoglobulinemic vasculitis (CV), a 53-year-old male contracted coronavirus disease 2019 (COVID-19), resulting in a disease flare. Although HCV became negative due to the use of glecaprevir/pibrentasvir, CV remained uncontrolled, and the patient was treated with prednisolone, azathioprine, colchicine, and rituximab. He had not been vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He was infected with SARS-CoV-2, likely the omicron variant, and developed a severe illness. However, mechanical ventilation and the administration of remdesivir, dexamethasone, unfractionated heparin, and tocilizumab improved his respiratory failure. Despite improvement in respiratory failure, the patient's skin lesions and peripheral neuropathy rapidly worsened, followed by the development of intestinal ischemia, which led to death. To the best of our knowledge, this is the first case of acute exacerbation immediately after SARS-CoV-2 infection of HCV-associated CV on immunosuppressive therapy., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Hamazaki et al.)
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- 2022
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23. Age-associated decline of MondoA drives cellular senescence through impaired autophagy and mitochondrial homeostasis.
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Yamamoto-Imoto H, Minami S, Shioda T, Yamashita Y, Sakai S, Maeda S, Yamamoto T, Oki S, Takashima M, Yamamuro T, Yanagawa K, Edahiro R, Iwatani M, So M, Tokumura A, Abe T, Imamura R, Nonomura N, Okada Y, Ayer DE, Ogawa H, Hara E, Takabatake Y, Isaka Y, Nakamura S, and Yoshimori T
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- Animals, Autophagy physiology, Basic Helix-Loop-Helix Leucine Zipper Transcription Factors, Homeostasis, Mice, Mitochondria, Acute Kidney Injury, Cellular Senescence
- Abstract
Accumulation of senescent cells affects organismal aging and the prevalence of age-associated disease. Emerging evidence suggests that activation of autophagy protects against age-associated diseases and promotes longevity, but the roles and regulatory mechanisms of autophagy in cellular senescence are not well understood. Here, we identify the transcription factor, MondoA, as a regulator of cellular senescence, autophagy, and mitochondrial homeostasis. MondoA protects against cellular senescence by activating autophagy partly through the suppression of an autophagy-negative regulator, Rubicon. In addition, we identify peroxiredoxin 3 (Prdx3) as another downstream regulator of MondoA essential for mitochondrial homeostasis and autophagy. Rubicon and Prdx3 work independently to regulate senescence. Furthermore, we find that MondoA knockout mice have exacerbated senescence during ischemic acute kidney injury (AKI), and a decrease of MondoA in the nucleus is correlated with human aging and ischemic AKI. Our results suggest that decline of MondoA worsens senescence and age-associated disease., Competing Interests: Declaration of interests T.Y. is a founder of AutoPhagyGO., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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24. Identification of a selective DDX3X inhibitor with newly developed quantitative high-throughput RNA helicase assays.
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Nakao S, Nogami M, Iwatani M, Imaeda T, Ito M, Tanaka T, Tawada M, Endo S, Cary DR, Ohori M, Imaeda Y, Kawamoto T, Aparicio S, Nakanishi A, and Araki S
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- DEAD-box RNA Helicases metabolism, Drug Discovery methods, Drug Evaluation, Preclinical methods, Enzyme Assays methods, Eukaryotic Initiation Factor-4A metabolism, High-Throughput Screening Assays, Humans, Small Molecule Libraries chemistry, DEAD-box RNA Helicases antagonists & inhibitors, Eukaryotic Initiation Factor-4A antagonists & inhibitors, Small Molecule Libraries pharmacology
- Abstract
The DEAD-box family of RNA helicases plays essential roles in both transcriptional and translational mRNA degradation; they unwind short double-stranded RNA by breaking the RNA-RNA interactions. Two DEAD-box RNA helicases, eukaryotic translation initiation factor 4A3 (eIF4A3) and DEAD-box helicase 3 (DDX3X), show high homology in the ATP-binding region and are considered key molecules for cancer progression. Several small molecules that target eIF4A3 and DDX3X have been reported to inhibit cancer cell growth; however, more potent compounds are required for cancer therapeutics, and there is a critical need for high-throughput assays to screen for RNA helicase inhibitors. In this study, we developed novel fluorescence resonance energy transfer-based high-throughput RNA helicase assays for eIF4A3 and DDX3X. Using these assays, we identified several eIF4A3 allosteric inhibitors whose inhibitory effect on eIF4A3 ATPase showed a strong correlation with inhibitory effect on helicase activity. From 102 compounds that exhibited eIF4A3 ATPase inhibition, we identified a selective DDX3X inhibitor, C1, which showed stronger inhibition of DDX3X than of eIF4A3. Small-molecule helicase inhibitors can be valuable for clarifying the molecular machinery of DEAD-box RNA helicases. The high-throughput quantitative assays established here should facilitate the evaluation of the helicase inhibitory activity of compounds., Competing Interests: Declaration of competing interest In accordance with the journal’s policy regarding conflicts of interest: SN, MN, MI, TI, MIto, TT, MT, SE, DC, MO, YI, TK, AN, and SAr are/were employees of Takeda Pharmaceutical Co. Ltd., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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25. T-448, a specific inhibitor of LSD1 enzyme activity, improves learning function without causing thrombocytopenia in mice.
- Author
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Matsuda S, Baba R, Oki H, Morimoto S, Toyofuku M, Igaki S, Kamada Y, Iwasaki S, Matsumiya K, Hibino R, Kamada H, Hirakawa T, Iwatani M, Tsuchida K, Hara R, Ito M, and Kimura H
- Subjects
- Animals, Benzamides adverse effects, Brain metabolism, Cells, Cultured, Enzyme Inhibitors pharmacology, Histone Demethylases metabolism, Histones metabolism, Humans, Male, Methylation drug effects, Mice, Neurons metabolism, Primary Cell Culture, Proto-Oncogene Proteins metabolism, Rats, Repressor Proteins metabolism, Benzamides pharmacology, Histone Demethylases antagonists & inhibitors, Maze Learning drug effects, Thrombocytopenia chemically induced
- Abstract
Dysregulation of histone H3 lysine 4 (H3K4) methylation has been implicated in the pathogenesis of several neurodevelopmental disorders. Targeting lysine-specific demethylase 1 (LSD1), an H3K4 demethylase, is therefore a promising approach to treat these disorders. However, LSD1 forms complexes with cofactors including growth factor independent 1B (GFI1B), a critical regulator of hematopoietic differentiation. Known tranylcypromine-based irreversible LSD1 inhibitors bind to coenzyme flavin adenine dinucleotide (FAD) and disrupt the LSD1-GFI1B complex, which is associated with hematotoxicity such as thrombocytopenia, representing a major hurdle in the development of LSD1 inhibitors as therapeutic agents. To discover LSD1 inhibitors with potent epigenetic modulation and lower risk of hematotoxicity, we screened small molecules that enhance H3K4 methylation by the inhibition of LSD1 enzyme activity in primary cultured rat neurons but have little impact on LSD1-GFI1B complex in human TF-1a erythroblasts. Here we report the discovery of a specific inhibitor of LSD1 enzyme activity, T-448 (3-((1S,2R)-2-(cyclobutylamino)cyclopropyl)-N-(5-methyl-1,3,4-thiadiazol-2-yl)benzamide fumarate). T-448 has minimal impact on the LSD1-GFI1B complex and a superior hematological safety profile in mice via the generation of a compact formyl-FAD adduct. T-448 increased brain H3K4 methylation and partially restored learning function in mice with NMDA receptor hypofunction. T-448-type LSD1 inhibitors with improved safety profiles may provide unique therapeutic approaches for central nervous system disorders associated with epigenetic dysregulation.
- Published
- 2019
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26. Anti-tumor efficacy of a novel CLK inhibitor via targeting RNA splicing and MYC-dependent vulnerability.
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Iwai K, Yaguchi M, Nishimura K, Yamamoto Y, Tamura T, Nakata D, Dairiki R, Kawakita Y, Mizojiri R, Ito Y, Asano M, Maezaki H, Nakayama Y, Kaishima M, Hayashi K, Teratani M, Miyakawa S, Iwatani M, Miyamoto M, Klein MG, Lane W, Snell G, Tjhen R, He X, Pulukuri S, and Nomura T
- Subjects
- Animals, Cell Line, Tumor, Diamines chemistry, Genes, myc, Humans, Mice, Mice, Transgenic, Phosphorylation, Protein Kinase Inhibitors chemistry, Protein Serine-Threonine Kinases metabolism, Protein-Tyrosine Kinases metabolism, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, Proto-Oncogene Proteins c-myc physiology, Pyrimidines chemistry, Quinolines chemistry, RNA Splicing genetics, Diamines pharmacology, Protein Kinase Inhibitors pharmacology, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases antagonists & inhibitors, Pyrimidines pharmacology, Quinolines pharmacology, RNA Splicing drug effects
- Abstract
The modulation of pre-mRNA splicing is proposed as an attractive anti-neoplastic strategy, especially for the cancers that exhibit aberrant pre-mRNA splicing. Here, we discovered that T-025 functions as an orally available and potent inhibitor of Cdc2-like kinases (CLKs), evolutionally conserved kinases that facilitate exon recognition in the splicing machinery. Treatment with T-025 reduced CLK-dependent phosphorylation, resulting in the induction of skipped exons, cell death, and growth suppression in vitro and in vivo Further, through growth inhibitory characterization, we identified high CLK2 expression or MYC amplification as a sensitive-associated biomarker of T-025. Mechanistically, the level of CLK2 expression correlated with the magnitude of global skipped exons in response to T-025 treatment. MYC activation, which altered pre-mRNA splicing without the transcriptional regulation of CLKs, rendered cancer cells vulnerable to CLK inhibitors with synergistic cell death. Finally, we demonstrated in vivo anti-tumor efficacy of T-025 in an allograft model of spontaneous, MYC-driven breast cancer, at well-tolerated dosage. Collectively, our results suggest that the novel CLK inhibitor could have therapeutic benefits, especially for MYC-driven cancer patients., (© 2018 Takeda Pharmaceutical Company Published under the terms of the CC BY 4.0 license.)
- Published
- 2018
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27. Discovery of spiro[indole-3,2'-pyrrolidin]-2(1H)-one based inhibitors targeting Brr2, a core component of the U5 snRNP.
- Author
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Ito M, Iwatani M, Yamamoto T, Tanaka T, Kawamoto T, Morishita D, Nakanishi A, and Maezaki H
- Subjects
- Humans, Indoles chemistry, Inhibitory Concentration 50, Protein Binding, RNA Helicases antagonists & inhibitors, RNA Helicases metabolism, Recombinant Proteins biosynthesis, Recombinant Proteins chemistry, Recombinant Proteins isolation & purification, Ribonucleoproteins, Small Nuclear genetics, Ribonucleoproteins, Small Nuclear metabolism, Spiro Compounds metabolism, Structure-Activity Relationship, Ribonucleoproteins, Small Nuclear antagonists & inhibitors, Spiro Compounds chemistry
- Abstract
Bad response to refrigeration 2 (Brr2) is a member of the Ski2-like RNA helicases, and an essential component of the U5 small nuclear ribonucleoprotein (snRNP). A particularly important role of Brr2 is the ATP-dependent unwinding of the U4/U6 RNA duplex, which is a critical step in spliceosomal activation. Despite its biological importance, selective inhibitor for Brr2 had not been reported until our recent report. Here, we describe novel and structurally distinct spiro[indole-3,2'-pyrrolidin]-2(1H)-one based Brr2 inhibitors with superior activity to the previously reported 4,6-dihydropyrido[4,3-d]pyrimidine-2,7(1H,3H)-dione series. Using an RNA dependent ATPase assay as a guide, high-throughput screening, hit validation by structure-activity relationship (SAR) study, and subsequent chemical optimization to increase the ATPase inhibitory activity were performed. Thereafter, selectivity and helicase inhibitory activity of optimized compounds were confirmed. In the course of the study, compounds were synthesized using a three-component reaction, which accelerated the optimization process. All these efforts finally culminated in the discovery of the potent and selective Brr2 inhibitors (32a and 33a) exhibiting helicase inhibitory activity at submicromolar concentrations. Thus, compounds 32a and 33a could be valuable molecular probes to study the functions of Brr2 and molecular machinery of RNA splicing., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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28. Prolyl-tRNA synthetase inhibition promotes cell death in SK-MEL-2 cells through GCN2-ATF4 pathway activation.
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Arita T, Morimoto M, Yamamoto Y, Miyashita H, Kitazawa S, Hirayama T, Sakamoto S, Miyamoto K, Adachi R, Iwatani M, and Hara T
- Subjects
- Amino Acyl-tRNA Synthetases metabolism, Animals, Antineoplastic Agents chemistry, Cell Death drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Enzyme Inhibitors chemistry, Humans, Mice, Mice, Inbred BALB C, Mice, Nude, Molecular Structure, Neoplasms, Experimental drug therapy, Neoplasms, Experimental pathology, Picolinic Acids chemistry, Pyrrolidinones chemistry, Structure-Activity Relationship, Activating Transcription Factor 4 metabolism, Amino Acyl-tRNA Synthetases antagonists & inhibitors, Antineoplastic Agents pharmacology, Enzyme Inhibitors pharmacology, Picolinic Acids pharmacology, Protein Serine-Threonine Kinases metabolism, Pyrrolidinones pharmacology
- Abstract
Protein translation is highly activated in cancer tissues through oncogenic mutations and amplifications, and this can support survival and aberrant proliferation. Therefore, blocking translation could be a promising way to block cancer progression. The process of charging a cognate amino acid to tRNA, a crucial step in protein synthesis, is mediated by tRNA synthetases such as prolyl tRNA synthetase (PRS). Interestingly, unlike pan-translation inhibitors, we demonstrated that a novel small molecule PRS inhibitor (T-3861174) induced cell death in several tumor cell lines including SK-MEL-2 without complete suppression of translation. Additionally, our findings indicated that T-3861174-induced cell death was caused by activation of the GCN2-ATF4 pathway. Furthermore, the PRS inhibitor exhibited significant anti-tumor activity in several xenograft models without severe body weight losses. These results indicate that PRS is a druggable target, and suggest that T-3861174 is a potential therapeutic agent for cancer therapy., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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29. Discovery of selective ATP-competitive eIF4A3 inhibitors.
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Ito M, Iwatani M, Kamada Y, Sogabe S, Nakao S, Tanaka T, Kawamoto T, Aparicio S, Nakanishi A, and Imaeda Y
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- Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Drug Discovery, Enzyme Inhibitors chemistry, High-Throughput Screening Assays, History, Medieval, Proton Magnetic Resonance Spectroscopy, Spectrometry, Mass, Electrospray Ionization, Adenosine Triphosphate metabolism, DEAD-box RNA Helicases antagonists & inhibitors, Enzyme Inhibitors pharmacology, Eukaryotic Initiation Factor-4A antagonists & inhibitors
- Abstract
Eukaryotic initiation factor 4A3 (eIF4A3), an ATP-dependent RNA helicase, is a core component of exon junction complex (EJC). EJC has a variety of roles in RNA metabolism such as translation, surveillance, and localization of spliced RNA. It is worthwhile to identify selective eIF4A3 inhibitors with a view to investigating the functions of eIF4A3 and EJC further to clarify the roles of the ATPase and helicase activities in cells. Our chemical optimization of hit compound 2 culminated in the discovery of ATP-competitive eIF4A3 inhibitor 18 with submicromolar ATPase inhibitory activity and excellent selectivity over other helicases. Hence, compound 18 could be a valuable chemical probe to elucidate the detailed functions of eIF4A3 and EJC., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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30. CLK-dependent exon recognition and conjoined gene formation revealed with a novel small molecule inhibitor.
- Author
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Funnell T, Tasaki S, Oloumi A, Araki S, Kong E, Yap D, Nakayama Y, Hughes CS, Cheng SG, Tozaki H, Iwatani M, Sasaki S, Ohashi T, Miyazaki T, Morishita N, Morishita D, Ogasawara-Shimizu M, Ohori M, Nakao S, Karashima M, Sano M, Murai A, Nomura T, Uchiyama N, Kawamoto T, Hara R, Nakanishi O, Shumansky K, Rosner J, Wan A, McKinney S, Morin GB, Nakanishi A, Shah S, Toyoshiba H, and Aparicio S
- Subjects
- Exons, Gene Expression Profiling, Genome, Human, HCT116 Cells, Humans, Imidazoles chemical synthesis, Phosphorylation drug effects, Protein Kinase Inhibitors chemical synthesis, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Serine-Threonine Kinases metabolism, Protein-Tyrosine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases metabolism, Pyrimidines chemical synthesis, RNA, Messenger antagonists & inhibitors, RNA, Messenger metabolism, RNA, Small Interfering genetics, RNA, Small Interfering metabolism, RNA-Binding Proteins antagonists & inhibitors, RNA-Binding Proteins metabolism, Structure-Activity Relationship, Transcription, Genetic, Alternative Splicing drug effects, Imidazoles pharmacology, Protein Kinase Inhibitors pharmacology, Protein Serine-Threonine Kinases genetics, Protein-Tyrosine Kinases genetics, Pyrimidines pharmacology, RNA, Messenger genetics, RNA-Binding Proteins genetics
- Abstract
CDC-like kinase phosphorylation of serine/arginine-rich proteins is central to RNA splicing reactions. Yet, the genomic network of CDC-like kinase-dependent RNA processing events remains poorly defined. Here, we explore the connectivity of genomic CDC-like kinase splicing functions by applying graduated, short-exposure, pharmacological CDC-like kinase inhibition using a novel small molecule (T3) with very high potency, selectivity, and cell-based stability. Using RNA-Seq, we define CDC-like kinase-responsive alternative splicing events, the large majority of which monotonically increase or decrease with increasing CDC-like kinase inhibition. We show that distinct RNA-binding motifs are associated with T3 response in skipped exons. Unexpectedly, we observe dose-dependent conjoined gene transcription, which is associated with motif enrichment in the last and second exons of upstream and downstream partners, respectively. siRNA knockdown of CLK2-associated genes significantly increases conjoined gene formation. Collectively, our results reveal an unexpected role for CDC-like kinase in conjoined gene formation, via regulation of 3'-end processing and associated splicing factors.The phosphorylation of serine/arginine-rich proteins by CDC-like kinase is a central regulatory mechanism for RNA splicing reactions. Here, the authors synthesize a novel small molecule CLK inhibitor and map CLK-responsive alternative splicing events and discover an effect on conjoined gene transcription.
- Published
- 2017
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31. A Novel LSD1 Inhibitor T-3775440 Disrupts GFI1B-Containing Complex Leading to Transdifferentiation and Impaired Growth of AML Cells.
- Author
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Ishikawa Y, Gamo K, Yabuki M, Takagi S, Toyoshima K, Nakayama K, Nakayama A, Morimoto M, Miyashita H, Dairiki R, Hikichi Y, Tomita N, Tomita D, Imamura S, Iwatani M, Kamada Y, Matsumoto S, Hara R, Nomura T, Tsuchida K, and Nakamura K
- Subjects
- Animals, Antineoplastic Agents chemistry, Cell Line, Tumor, Cell Proliferation drug effects, Cluster Analysis, Computational Biology methods, Disease Models, Animal, Drug Resistance, Neoplasm, Female, Gene Expression Profiling, Gene Knockdown Techniques, Hematopoiesis genetics, Histone Demethylases genetics, Histone Demethylases metabolism, Humans, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute genetics, Mice, Molecular Targeted Therapy, Protein Binding, Proto-Oncogene Proteins genetics, Repressor Proteins genetics, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Cell Transdifferentiation drug effects, Histone Demethylases antagonists & inhibitors, Leukemia, Myeloid, Acute metabolism, Leukemia, Myeloid, Acute pathology, Multiprotein Complexes metabolism, Proto-Oncogene Proteins metabolism, Repressor Proteins metabolism
- Abstract
Dysregulation of lysine (K)-specific demethylase 1A (LSD1), also known as KDM1A, has been implicated in the development of various cancers, including leukemia. Here, we describe the antileukemic activity and mechanism of action of T-3775440, a novel irreversible LSD1 inhibitor. Cell growth analysis of leukemia cell lines revealed that acute erythroid leukemia (AEL) and acute megakaryoblastic leukemia cells (AMKL) were highly sensitive to this compound. T-3775440 treatment enforced transdifferentiation of erythroid/megakaryocytic lineages into granulomonocytic-like lineage cells. Mechanistically, T-3775440 disrupted the interaction between LSD1 and growth factor-independent 1B (GFI1B), a transcription factor critical for the differentiation processes of erythroid and megakaryocytic lineage cells. Knockdown of LSD1 and GFI1B recapitulated T-3775440-induced transdifferentiation and cell growth suppression, highlighting the significance of LSD1-GFI1B axis inhibition with regard to the anti-AML effects of T-3775440. Moreover, T-3775440 exhibited significant antitumor efficacy in AEL and AMKL xenograft models. Our findings provide a rationale for evaluating LSD1 inhibitors as potential treatments and indicate a novel mechanism of action against AML, particularly AEL and AMKL. Mol Cancer Ther; 16(2); 273-84. ©2016 AACR., (©2016 American Association for Cancer Research.)
- Published
- 2017
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32. Mechanism of sonochemical reduction of permanganate to manganese dioxide in aqueous alcohol solutions: Reactivities of reducing species formed by alcohol sonolysis.
- Author
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Okitsu K, Iwatani M, Okano K, Uddin MH, and Nishimura R
- Abstract
The sonochemical reduction of MnO4(-) to MnO2 in aqueous solutions was investigated as a function of alcohol concentration under Ar. The rate of MnO4(-) reduction initially decreased with increasing alcohol concentration, and then increased when the alcohol concentration was increased further. The concentrations at which the reduction rates were minimum depended on the hydrophobic properties of the added alcohols under ultrasonic irradiation. At low concentrations, the alcohols acted as OH radical scavengers; at high concentrations, they acted as reductant precursors: Rab, formed by abstraction reactions of the alcohols with sonochemically formed OH radicals or H atoms, and Rpy, formed by alcohol pyrolysis under ultrasonic irradiation. The results suggest that the reactivity order of the sonochemically formed reducing species with MnO4(-) at pH 7-9 is the sum of H2O2 and H>Rpy>Rab. The peak wavelengths of MnO2 colloidal solutions formed at high 1-butanol concentrations shifted to shorter wavelengths, suggesting the formation of small particles at high 1-butanol concentrations. The rates of sonochemical reduction of MnO2 to Mn(2+) in the presence of 1-butanol were slower than that in the absence of 1-butanol, because the sonochemical formation of H2O2 and H, which act as reductants, was suppressed by 1-butanol in aqueous solutions., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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33. Inhibitors of CLK protein kinases suppress cell growth and induce apoptosis by modulating pre-mRNA splicing.
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Araki S, Dairiki R, Nakayama Y, Murai A, Miyashita R, Iwatani M, Nomura T, and Nakanishi O
- Subjects
- Apoptosis genetics, Arginine antagonists & inhibitors, Arginine metabolism, Cell Line, Tumor, Cell Proliferation genetics, HCT116 Cells, Humans, Nuclear Proteins antagonists & inhibitors, Nuclear Proteins metabolism, Phosphorylation drug effects, Phosphorylation genetics, Protein Isoforms antagonists & inhibitors, Protein Isoforms metabolism, Protein Serine-Threonine Kinases metabolism, Protein-Tyrosine Kinases metabolism, RNA Precursors genetics, RNA Precursors metabolism, RNA Splicing genetics, RNA-Binding Proteins metabolism, Apoptosis drug effects, Cell Proliferation drug effects, Protein Kinase Inhibitors pharmacology, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases antagonists & inhibitors, RNA Splicing drug effects, RNA, Messenger genetics, Small Molecule Libraries pharmacology
- Abstract
Accumulating evidence has demonstrated the importance of alternative splicing in various physiological processes, including the development of different diseases. CDC-like kinases (CLKs) and serine-arginine protein kinases (SRPKs) are components of the splicing machinery that are crucial for exon selection. The discovery of small molecule inhibitors against these kinases is of significant value, not only to delineate the molecular mechanisms of splicing, but also to identify potential therapeutic opportunities. Here we describe a series of small molecules that inhibit CLKs and SRPKs and thereby modulate pre-mRNA splicing. Treatment with these small molecules (Cpd-1, Cpd-2, or Cpd-3) significantly reduced the levels of endogenous phosphorylated SR proteins and caused enlargement of nuclear speckles in MDA-MB-468 cells. Additionally, the compounds resulted in splicing alterations of RPS6KB1 (S6K), and subsequent depletion of S6K protein. Interestingly, the activity of compounds selective for CLKs was well correlated with the activity for modulating S6K splicing as well as growth inhibition of cancer cells. A comprehensive mRNA sequencing approach revealed that the inhibitors induced splicing alterations and protein depletion for multiple genes, including those involved in growth and survival pathways such as S6K, EGFR, EIF3D, and PARP. Fluorescence pulse-chase labeling analyses demonstrated that isoforms with premature termination codons generated after treatment with the CLK inhibitors were degraded much faster than canonical mRNAs. Taken together, these results suggest that CLK inhibitors exhibit growth suppression and apoptosis induction through splicing alterations in genes involved in growth and survival. These small molecule inhibitors may be valuable tools for elucidating the molecular machinery of splicing and for the potential development of a novel class of antitumor agents.
- Published
- 2015
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34. In vitro characterization of the RS motif in N-terminal head domain of goldfish germinal vesicle lamin B3 necessary for phosphorylation of the p34cdc2 target serine by SRPK1.
- Author
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Yamaguchi A, Iwatani M, Ogawa M, Kitano H, and Matsuyama M
- Abstract
The nuclear envelopes surrounding the oocyte germinal vesicles of lower vertebrates (fish and frog) are supported by the lamina, which consists of the protein lamin B3 encoded by a gene found also in birds but lost in the lineage leading to mammals. Like other members of the lamin family, goldfish lamin B3 (gfLB3) contains two putative consensus phosphoacceptor p34cdc2 sites (Ser-28 and Ser-398) for the M-phase kinase to regulate lamin polymerization on the N- and C-terminal regions flanking a central rod domain. Partial phosphorylation of gfLB3 occurs on Ser-28 in the N-terminal head domain in immature oocytes prior to germinal vesicle breakdown, which suggests continual rearrangement of lamins by a novel lamin kinase in fish oocytes. We applied the expression-screening method to isolate lamin kinases by using phosphorylation site Ser-28-specific monoclonal antibody and a vector encoding substrate peptides from a goldfish ovarian cDNA library. As a result, SRPK1 was screened as a prominent lamin kinase candidate. The gfLB3 has a short stretch of the RS repeats (9-SRASTVRSSRRS-20) upstream of the Ser-28, within the N-terminal head. This stretch of repeats is conserved among fish lamin B3 but is not found in other lamins. In vitro phosphorylation studies and GST-pull down assay revealed that SRPK1 bound to the region of sequential RS repeats (9-20) with affinity and recruited serine into the active site by a grab-and-pull manner. These results indicate SRPK1 may phosphorylate the p34cdc2 site in the N-terminal head of GV-lamin B3 at the RS motifs, which have the general property of aggregation.
- Published
- 2013
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35. Structure-based discovery of cellular-active allosteric inhibitors of FAK.
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Tomita N, Hayashi Y, Suzuki S, Oomori Y, Aramaki Y, Matsushita Y, Iwatani M, Iwata H, Okabe A, Awazu Y, Isono O, Skene RJ, Hosfield DJ, Miki H, Kawamoto T, Hori A, and Baba A
- Subjects
- Allosteric Site, Antineoplastic Agents chemical synthesis, Antineoplastic Agents metabolism, Binding Sites, Crystallography, X-Ray, Cyclic S-Oxides chemical synthesis, Cyclic S-Oxides metabolism, Drug Evaluation, Preclinical, Focal Adhesion Protein-Tyrosine Kinases metabolism, Heterocyclic Compounds, 3-Ring chemical synthesis, Heterocyclic Compounds, 3-Ring metabolism, Molecular Docking Simulation, Protein Binding, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors metabolism, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Serine-Threonine Kinases metabolism, Protein Structure, Tertiary, Protein-Tyrosine Kinases antagonists & inhibitors, Protein-Tyrosine Kinases metabolism, Structure-Activity Relationship, Thiazines chemical synthesis, Thiazines metabolism, Antineoplastic Agents chemistry, Cyclic S-Oxides chemistry, Focal Adhesion Protein-Tyrosine Kinases antagonists & inhibitors, Heterocyclic Compounds, 3-Ring chemistry, Protein Kinase Inhibitors chemistry, Thiazines chemistry
- Abstract
In order to develop potent and selective focal adhesion kinase (FAK) inhibitors, synthetic studies on pyrazolo[4,3-c][2,1]benzothiazines targeted for the FAK allosteric site were carried out. Based on the X-ray structural analysis of the co-crystal of the lead compound, 8-(4-ethylphenyl)-5-methyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazine 4,4-dioxide 1 with FAK, we designed and prepared 1,5-dimethyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazin derivatives which selectively inhibited kinase activity of FAK without affecting seven other kinases. The optimized compound, N-(4-tert-butylbenzyl)-1,5-dimethyl-1,5-dihydropyrazolo[4,3-c][2,1]benzothiazin-8-amine 4,4-dioxide 30 possessed significant FAK kinase inhibitory activities both in cell-free (IC50=0.64μM) and in cellular assays (IC50=7.1μM). These results clearly demonstrated a potential of FAK allosteric inhibitors as antitumor agents., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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36. Discovery and characterization of novel allosteric FAK inhibitors.
- Author
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Iwatani M, Iwata H, Okabe A, Skene RJ, Tomita N, Hayashi Y, Aramaki Y, Hosfield DJ, Hori A, Baba A, and Miki H
- Subjects
- Allosteric Regulation drug effects, Dose-Response Relationship, Drug, Humans, Models, Molecular, Molecular Structure, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors chemistry, Pyrazoles chemical synthesis, Pyrazoles chemistry, Structure-Activity Relationship, Thiazines chemical synthesis, Thiazines chemistry, Drug Discovery, Focal Adhesion Protein-Tyrosine Kinases antagonists & inhibitors, Protein Kinase Inhibitors pharmacology, Pyrazoles pharmacology, Thiazines pharmacology
- Abstract
Focal adhesion kinase (FAK) regulates cell survival and proliferation pathways. Here we report the discovery of a highly selective series of 1,5-dihydropyrazolo[4,3-c][2,1]benzothiazines that demonstrate a novel mode of allosteric inhibition of FAK. These compounds showed slow dissociation from unphosphorylated FAK and were noncompetitive with ATP after long preincubation. Co-crystal structural analysis revealed that the compounds target a novel allosteric site within the C-lobe of the kinase domain, which induces disruption of ATP pocket formation leading to the inhibition of kinase activity. The potency of allosteric inhibition was reduced by phosphorylation of FAK. Coupled SAR analysis revealed that N-substitution of the fused pyrazole is critical to achieve allosteric binding and high selectivity among kinases., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)
- Published
- 2013
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37. Genome-wide DNA methylation profile of tissue-dependent and differentially methylated regions (T-DMRs) residing in mouse pluripotent stem cells.
- Author
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Sato S, Yagi S, Arai Y, Hirabayashi K, Hattori N, Iwatani M, Okita K, Ohgane J, Tanaka S, Wakayama T, Yamanaka S, and Shiota K
- Subjects
- Animals, Cluster Analysis, CpG Islands genetics, Embryonic Stem Cells cytology, Mice, Models, Genetic, Oligonucleotide Array Sequence Analysis, Polymerase Chain Reaction, DNA Methylation, Gene Expression Profiling methods, Genome genetics, Pluripotent Stem Cells metabolism
- Abstract
DNA methylation profile, consisting of tissue-dependent and differentially methylated regions (T-DMRs), has elucidated tissue-specific gene function in mouse tissues. Here, we identified and profiled thousands of T-DMRs in embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs). T-DMRs of ESCs compared with somatic tissues well illustrated gene function of ESCs, by hypomethylation at genes associated with CpG islands and nuclear events including transcriptional regulation network of ESCs, and by hypermethylation at genes for tissue-specific function. These T-DMRs in EGCs and iPSCs showed DNA methylation similar to ESCs. iPSCs, however, showed hypomethylation at a considerable number of T-DMRs that were hypermethylated in ESCs, suggesting existence of traceable progenitor epigenetic information. Thus, DNA methylation profile of T-DMRs contributes to the mechanism of pluripotency, and can be a feasible solution for identification and evaluation of the pluripotent cells.
- Published
- 2010
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38. Resistance to 5-aza-2'-deoxycytidine in genic regions compared to non-genic repetitive sequences.
- Author
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Lim HW, Iwatani M, Hattori N, Tanaka S, Yagi S, and Shiota K
- Subjects
- 3T3 Cells, Animals, Azacitidine pharmacology, Clusterin genetics, Clusterin metabolism, CpG Islands drug effects, Decitabine, Dipeptidases genetics, Dipeptidases metabolism, Epigenesis, Genetic drug effects, GPI-Linked Proteins, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Mice, Octamer Transcription Factor-3 genetics, Octamer Transcription Factor-3 metabolism, Period Circadian Proteins genetics, Period Circadian Proteins metabolism, Repetitive Sequences, Nucleic Acid drug effects, Transcription Factors genetics, Transcription Factors metabolism, Azacitidine analogs & derivatives, DNA Methylation drug effects, DNA Modification Methylases antagonists & inhibitors, Enzyme Inhibitors pharmacology
- Abstract
The DNA methyltransferase (Dnmt) inhibitor and demethylating agent 5-aza-2'-deoxycytidine (5azadC) has been used to induce cellular differentiation and gene activation. It has been approved for treating several kinds of malignancies due to its ability to reactivate silenced tumor suppressor genes. Considering the potential effect of 5azadC on non-targeted genomic regions in normal cells, we investigated its effect on repetitive sequences and selected gene loci, Oct-4, Sall3, Per1, Clu, Dpep1 and Igf2r, including tissue-dependent and differentially methylated regions, by treating mouse NIH/3T3 fibroblast cells with concentrations of 5azadC ranging from 0.001 to 5 microM. Demethylation of minor satellite repeats and endogenous viruses was concentration dependent, and the demethylation was strong at 1 and 5 microM. In genic regions, the methylation level decreased only at 0.1 microM, but was minimally altered at concentrations lower or higher, regardless of the abundance of CpG sites. Thus, repeats are strongly demethylated, but genic regions are only demethylated at effective doses. Genes were activated by 5azadC treatment and were accompanied by a unique combination of histone modifications in genic regions, including an increased level of H3K9me3 and a decreased level of AcH3. Increase of H3K9me3 in genic regions was not observed in Dnmt knock out cells. We identified differential effects of 5azadC on repetitive sequences and genic regions and revealed the importance of choosing appropriate 5azadC doses to achieve targeted gene recovery.
- Published
- 2010
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39. Establishment of trophoblast stem cell lines from somatic cell nuclear-transferred embryos.
- Author
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Oda M, Tanaka S, Yamazaki Y, Ohta H, Iwatani M, Suzuki M, Ohgane J, Hattori N, Yanagimachi R, Wakayama T, and Shiota K
- Subjects
- Animals, Blastocyst cytology, Blastocyst metabolism, Blotting, Northern, Cell Differentiation, Cell Line, Cell Lineage, Cellular Reprogramming, Embryo, Mammalian metabolism, Female, Gene Expression Profiling, Mice, Oligonucleotide Array Sequence Analysis, Spectral Karyotyping, Stem Cells metabolism, Trophoblasts metabolism, Embryo, Mammalian cytology, Nuclear Transfer Techniques, Stem Cells cytology, Trophoblasts cytology
- Abstract
Placental abnormalities occur frequently in cloned animals. Here, we attempted to isolate trophoblast stem (TS) cells from mouse blastocysts produced by somatic cell nuclear transfer (NT) at the blastocyst stage (NT blastocysts). Despite the predicted deficiency of the trophoblast cell lineage, we succeeded in isolating cell colonies with typical morphology of TS cells and cell lines from the NT blastocysts (ntTS cell lines) with efficiency as high as that from native blastocysts. The established 10 ntTS cell lines could be maintained in the undifferentiated state and induced to differentiate into several trophoblast subtypes in vitro. A comprehensive analysis of the transcriptional and epigenetic traits demonstrated that ntTS cells were indistinguishable from control TS cells. In addition, ntTS cells contributed exclusively to the placenta and survived until term in chimeras, indicating that ntTS cells have developmental potential as stem cells. Taken together, our data show that NT blastocysts contain cells that can produce TS cells in culture, suggesting that proper commitment to the trophoblast cell lineage in NT embryos occurs by the blastocyst stage.
- Published
- 2009
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40. Sonochemical reduction of permanganate to manganese dioxide: the effects of H2O2 formed in the sonolysis of water on the rates of reduction.
- Author
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Okitsu K, Iwatani M, Nanzai B, Nishimura R, and Maeda Y
- Subjects
- 1-Propanol chemistry, Oxidation-Reduction, Time Factors, Water chemistry, Hydrogen Peroxide chemical synthesis, Hydrogen Peroxide chemistry, Manganese Compounds chemical synthesis, Manganese Compounds chemistry, Oxides chemical synthesis, Oxides chemistry, Sonication
- Abstract
Chemical effects of ultrasound have been actively researched in the field of the synthesis of various metal nanoparticles and nanostructured materials. It is very important to understand the reduction mechanism of metal ions, because the reduction processes can be often applied to the synthesis of various materials. In this study, the sonochemical reduction of MnO4- to MnO2 in water under Ar atmosphere was investigated to discuss the reduction mechanism. It has been reported that H, OH, H2 and H2O2 are formed from the sonolysis of water. To understand the roles of H2O2 on the reduction, the reaction of MnO4- with H2O2 without ultrasonic irradiation was investigated. The obtained results suggested the progress of the following reaction: 2MnO4-+3H2O2-->2MnO2+3O2+2OH-+2H2O. In addition, the rates of the sonochemical reduction of MnO4- were investigated in the presence of 1-propanol, where 1-propanol acted as an OH radical scavenger so that the amounts of the sonochemically formed H2O2 molecules were able to be controlled. The results clearly indicated that the sonochemically formed H2O2 molecules as well as H2 molecules and H atoms play an important role for MnO4- reduction. This mechanism was also supported by the analysis of pH changes during ultrasonic irradiation: the pH value increased as the sonochemical reduction of MnO4- proceeded.
- Published
- 2009
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41. Radiographic repair in three Japanese patients with rheumatoid arthritis treated with bucillamine.
- Author
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Nanke Y, Iwatani M, Kobashigawa T, Yago T, Yamanaka H, and Kotake S
- Subjects
- Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Arthritis, Rheumatoid pathology, Arthrography, Cysteine therapeutic use, Disease Progression, Female, Humans, Joints pathology, Male, Middle Aged, Recovery of Function, Severity of Illness Index, Treatment Outcome, Arthritis, Rheumatoid diagnostic imaging, Arthritis, Rheumatoid drug therapy, Bone and Bones diagnostic imaging, Bone and Bones pathology, Cysteine analogs & derivatives
- Abstract
Bucillamine (Bc) is a cysteine derivative with two SH groups, and a homolog of D-penicillamine, a disease-modifying antirheumatic drug (DMARD) widely used in Japan. However, it remains unclear whether Bc repairs bone erosion in patients with RA. Here, we treated three RA patients with Bc who subsequently showed radiographic repair of erosions and cysts.
- Published
- 2009
- Full Text
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42. Genome-wide and locus-specific DNA hypomethylation in G9a deficient mouse embryonic stem cells.
- Author
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Ikegami K, Iwatani M, Suzuki M, Tachibana M, Shinkai Y, Tanaka S, Greally JM, Yagi S, Hattori N, and Shiota K
- Subjects
- Animals, Chromatin Immunoprecipitation, CpG Islands, Cysteine metabolism, DNA metabolism, Euchromatin enzymology, Euchromatin metabolism, Gene Deletion, Histone Methyltransferases, Histone-Lysine N-Methyltransferase genetics, Histones metabolism, Mice, Models, Genetic, Nucleosomes metabolism, Polymerase Chain Reaction, Protein Methyltransferases, DNA Methylation, Embryonic Stem Cells enzymology, Genome, Histone-Lysine N-Methyltransferase metabolism
- Abstract
In the mammalian genome, numerous CpG-rich loci define tissue-dependent and differentially methylated regions (T-DMRs). Euchromatin from different cell types differs in terms of its tissue-specific DNA methylation profile as defined by these T-DMRs. G9a is a euchromatin-localized histone methyltransferase (HMT) and catalyzes methylation of histone H3 at lysines 9 and 27 (H3-K9 and -K27). To test whether HMT activity influences euchromatic cytosine methylation, we analyzed the DNA methylation status of approximately 2000 CpG-rich loci, which are predicted in silico, in G9a(-/-) embryonic stem cells by restriction landmark genomic scanning (RLGS). While the RLGS profile of wild-type cells contained about 1300 spots, 32 new spots indicating DNA demethylation were seen in the profile of G9a(-/-) cells. Virtual-image RLGS (Vi-RLGS) allowed us to identify the genomic source of ten of these spots. These were confirmed to be cytosine demethylated, not just at the Not I site detected by the RLGS but extending over several kilobase pairs in cis. Chromatin immunoprecipitation (ChIP) confirmed these loci to be targets of G9a, with decreased H3-K9 and/or -K27 dimethylation in the G9a(-/-) cells. These data indicate that G9a site-selectively contributes to DNA methylation.
- Published
- 2007
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43. Dimethyl sulfoxide has an impact on epigenetic profile in mouse embryoid body.
- Author
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Iwatani M, Ikegami K, Kremenska Y, Hattori N, Tanaka S, Yagi S, and Shiota K
- Subjects
- Animals, Blotting, Southern, Blotting, Western, Cell Differentiation drug effects, Cell Line, Cryoprotective Agents pharmacology, DNA (Cytosine-5-)-Methyltransferases genetics, DNA Methylation drug effects, DNA Methyltransferase 3A, Dose-Response Relationship, Drug, Homeodomain Proteins metabolism, Mice, Mice, Inbred C57BL, RNA, Messenger metabolism, Repetitive Sequences, Nucleic Acid drug effects, Reverse Transcriptase Polymerase Chain Reaction, Solvents pharmacology, Transcription Factors metabolism, DNA (Cytosine-5-)-Methyltransferases metabolism, Dimethyl Sulfoxide pharmacology, Embryonic Stem Cells drug effects, Epigenesis, Genetic drug effects, Gene Expression Regulation, Developmental drug effects
- Abstract
Dimethyl sulfoxide (DMSO), an amphipathic molecule, is widely used not only as a solvent for water-insoluble substances but also as a cryopreservant for various types of cells. Exposure to DMSO sometimes causes unexpected changes in cell fates. Because mammalian development and cellular differentiation are controlled epigenetically by DNA methylation and histone modifications, DMSO likely affects the epigenetic system. The effects of DMSO on transcription of three major DNA methyltransferases (Dnmts) and five well-studied histone modification enzymes were examined in mouse embryonic stem cells and embryoid bodies (EBs) by reverse transcription-polymerase chain reaction. Addition of DMSO (0.02%-1.0%) to EBs in culture induced an increase in Dnmt3a mRNA levels with increasing dosage. Increased expression of two subtypes of Dnmt3a in protein levels was confirmed by Western blotting. Southern blot analysis revealed that DMSO caused hypermethylation of two kinds of repetitive sequences in EBs. Furthermore, restriction landmark genomic scanning, by which DNA methylation status can be analyzed on thousands of loci in genic regions, revealed that DMSO affected DNA methylation status at multiple loci, inducing hypomethylation as well as hypermethylation depending on the genomic loci. In conclusion, DMSO has an impact on the epigenetic profile: upregulation of Dnmt3a expression and alteration of genome-wide DNA methylation profiles with phenotypic changes in EBs.
- Published
- 2006
- Full Text
- View/download PDF
44. Efficacy profile of bucillamine in rheumatoid arthritis patients in a large observational cohort study, IORRA.
- Author
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Iwatani M, Inoue E, Nakamura T, Nakajima A, Hara M, Tomatsu T, Kamatani N, and Yamanaka H
- Subjects
- Arthritis, Rheumatoid diagnosis, Arthritis, Rheumatoid physiopathology, Cohort Studies, Cysteine therapeutic use, Drug Therapy, Combination, Female, Health Status, Humans, Joints drug effects, Joints pathology, Male, Methotrexate therapeutic use, Middle Aged, Pain drug therapy, Pain pathology, Pain physiopathology, Prednisolone, Prospective Studies, Remission Induction, Severity of Illness Index, Sulfasalazine therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Arthritis, Rheumatoid drug therapy, Cysteine analogs & derivatives
- Abstract
Bucillamine (Buc) is a disease-modifying antirheumatic drug (DMARD) developed in Japan, which has been used as one of the first-line DMARDs for the treatment of rheumatoid arthritis (RA) in Japan. However, direct comparison of this drug with standard DMARDs including sulfasalazine (SASP) and methotrexate (MTX) has been scarcely reported. We therefore tried to evaluate the clinical efficacy of Buc by analyzing the database from the long-term observational cohort study IORRA (previously known as J-ARAMIS). The cross-sectional analysis revealed that responses to Buc treatment were better in males, patients with shorter duration of illness, and those who were rheumatoid factor-negative. In the longitudinal analysis, although there was no marked difference among the baseline variables of patients with Buc, SASP, and MTX, the percentage of patients exhibiting moderate or good response to treatment, as rated using the European League Against Rheumatism improvement criteria, was higher in the Buc group (41.0%) than in the MTX (32.6%) and SASP groups (25.6%). These data support Buc as a candidate for being a first-line drug for the treatment of patients with RA.
- Published
- 2006
- Full Text
- View/download PDF
45. [Diet therapy for management of hyperuricemia and gout].
- Author
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Iwatani M
- Subjects
- Adult, Alcoholic Beverages adverse effects, Alcoholic Beverages analysis, Gout etiology, Humans, Hyperuricemia etiology, Male, Obesity complications, Purines analysis, Purines metabolism, Uric Acid metabolism, Diet, Reducing, Gout diet therapy, Hyperuricemia diet therapy, Temperance
- Published
- 2003
46. [Uric acid metabolism and insulin resistance in type 2 diabetes].
- Author
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Wasada T and Iwatani M
- Subjects
- Cardiovascular Diseases etiology, Chromans pharmacology, Chromans therapeutic use, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 physiopathology, Humans, Hyperuricemia drug therapy, Hyperuricemia etiology, Thiazoles pharmacology, Thiazoles therapeutic use, Troglitazone, Diabetes Mellitus, Type 2 metabolism, Insulin Resistance, Thiazolidinediones, Uric Acid metabolism
- Published
- 2002
47. Influence of moderate drinking on purine and carbohydrate metabolism.
- Author
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Nishioka K, Sumida T, Iwatani M, Kusumoto A, Ishikura Y, Hatanaka H, Yomo H, Kohda H, Ashikari T, Shibano Y, and Suwa Y
- Subjects
- Adult, Beer, Humans, Male, Metabolic Clearance Rate physiology, Middle Aged, Purines administration & dosage, Alcohol Drinking metabolism, Alcoholic Beverages, Blood Glucose metabolism, Insulin blood, Purines blood, Uric Acid blood
- Abstract
Background: We examined the influences of a moderate intake level of three types of alcoholic beverages--beer, whisky, and Shochu (Japanese distilled liquor)--on purine and carbohydrate metabolism and excretion in healthy male volunteers, concerning (1) the extent of contribution of purine bodies contained in beer to uric acid metabolism and (2) a comparison between two types of distilled spirits with (whisky) and without (Shochu) aging in oak wood barrel storage., Methods: Three sets of studies were conducted in which 10 to 13 healthy adult men were instructed to drink three types of alcoholic beverages at a slightly higher level (0.8 ml of ethanol equivalent/kg body weight) than moderate drinking (approximately 30.4 ml or less for men). A low purine beer was test-manufactured by treating nucleosides that were contained in wort and remained in beer with purine nucleoside phosphorylase derived from Ochrobacterium anthropi, thereby converting them into corresponding purine bases that were easily assimilated by beer yeast., Results: Although beer intake enhanced the level of serum uric acid by 13.6%, blood glucose by 26.7%, and insulin level by 5.1-fold, drinking a moderate level of distilled liquor (whisky, Shochu) did not increase the serum uric acid level or the other two parameters. The serum uric acid level observed after drinking beer with a purine body concentration reduced by 28% (68% in nucleosides and purine bases) was almost identical to the level observed after drinking regular beer. Whisky has been found to have a property that decreases the serum uric acid level. Excretion of uric acid from blood is increased by 27% after drinking whisky., Conclusions: Moderate drinking of distilled liquors did not enhance serum uric acid level, blood glucose, or insulin level in healthy male subjects. Increased serum uric acid after beer intake could not be explained mostly with their purine body congeners. Whisky showed the eliminative property in serum uric acid through excretion of it from blood to urine. At a moderate drinking level, beer and whisky have different effects on purine metabolism or excretion.
- Published
- 2002
- Full Text
- View/download PDF
48. [Insulin sensitizer and urate metabolism].
- Author
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Iwatani M, Wasada T, Iwamoto Y, and Kamatani N
- Subjects
- Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 physiopathology, Female, Glucose metabolism, Humans, Hyperlipidemias, Hypertension, Male, Obesity, Syndrome, Troglitazone, Chromans therapeutic use, Gout drug therapy, Gout physiopathology, Hypoglycemic Agents therapeutic use, Insulin Resistance, Thiazoles therapeutic use, Thiazolidinediones, Uric Acid blood
- Abstract
Gout patients often have various characteristics of insulin resistance (IR) syndrome such as glucose intolerance, hyperlipidemia, hypertension and obesity. In addition, epidemiological data suggest that hyperuricemia is associated with higher rates of death due to cardiovascular and cerebrovascular disorders. However, it has not conclusively been shown whether the association between hyperuricemia and increased death rate is secondary to the association between IR and death or hyperuricemia itself is an independent risk of death. It is of interest to examine the effects of insulin sensitizer which was developed recently on serum urate concentration because it may provide a new idea as to the mechanism of the association between IR, hyperuricemia and vascular disorders. In the present paper, we discuss the relevance of IR to hyperuricemia and gout, and show the data of urate and glucose metabolism obtained from control subjects or the patients with hyperuricemia, gout or type 2 diabetes.
- Published
- 2000
49. Tarsal tunnel syndrome caused by tophaceous gout a case report.
- Author
-
Wakabayashi T, Irie K, Yamanaka H, Iwatani M, and Inoue K
- Published
- 1998
- Full Text
- View/download PDF
50. [Altered uric acid metabolism in diabetes mellitus].
- Author
-
Wasada T and Iwatani M
- Subjects
- Humans, Insulin Resistance physiology, Middle Aged, Diabetes Mellitus blood, Uric Acid blood
- Published
- 1997
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