1
|
Wakabayashi Y, Shimono A, Terauchi Y, Zeng C, Hamada M, Semba K, Watanabe S, Ishikawa K. Identification of a novel RNA transcript TISPL upregulated by stressors that stimulate ATF4. Gene 2024; 917:148464. [PMID: 38615981 DOI: 10.1016/j.gene.2024.148464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
Cells sense, respond, and adapt to environmental conditions that cause stress. In a previous study using HeLa cells, we isolated reporter cells responding to the endoplasmic reticulum (ER) stress inducers, thapsigargin and tunicamycin, using a highly sensitive promoter trap vector system. Splinkerette PCR and 5' rapid amplification of cDNA ends (5' RACE) identified a novel transcript that is upregulated by ER stress. Its endogenous expression increased approximately 10-fold in response to thapsigargin and tunicamycin within 1 h, but was down-regulated after 4 h. Because the transcript starts from an intron of a long noncoding RNA known as LINC-PINT, we designated the newly identified transcript TISPL (transcript induced by stressors from LINC-PINTlocus). TISPL was also expressed under several other stress conditions. It was particularly increased > 10-fold upon glucose starvation and 7-fold by arsenite exposure. Furthermore, in silico analyses, including a ChIP-atlas search, revealed that there is an ATF4-binding region with a c/ebp-Atf response element (CARE) downstream of the transcription start site of TISPL. Based on these results, we hypothesized that TISPL may be induced by the phospho-eIF2α and ATF4- axis of the integrated stress response pathway, which is known to be activated by the stress conditions listed above. As expected, knockout of ATF4 abolished the stress-induced upregulation of TISPL. Our results indicate that TISPL may be a useful biomarker for detecting stress conditions that activate ATF4. Our highly sensitive trap vector system proved beneficial in discovering new biomarkers.
Collapse
Affiliation(s)
- Yutaro Wakabayashi
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan; Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Aika Shimono
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Yuki Terauchi
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Chao Zeng
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan; Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Michiaki Hamada
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan; Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan; Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602, Japan
| | - Kentaro Semba
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan; Translational Research Center, Fukushima Medical University, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Shinya Watanabe
- Translational Research Center, Fukushima Medical University, 1 Hikarigaoka, Fukushima 960-1295, Japan
| | - Kosuke Ishikawa
- Japan Biological Informatics Consortium (JBiC), 2-4-32 Aomi, Koto-ku, Tokyo 135-8073, Japan.
| |
Collapse
|
2
|
Takahashi N, Terauchi Y, Tanaka T, Yoshimi A, Yabu H, Abe K. Involvement of ionic interactions in self-assembly and resultant rodlet formation of class I hydrophobin RolA from Aspergillus oryzae. Biosci Biotechnol Biochem 2023:7186926. [PMID: 37253619 DOI: 10.1093/bbb/zbad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Hydrophobins are small amphiphilic proteins that are conserved in filamentous fungi. They localized on the conidial surface to make it hydrophobic, which contributes to conidial dispersal in air, and help fungi to infect plants and mammals and to degrade polymers. Hydrophobins self-assemble and undergo structural transition from the amorphous state to the rodlet (rod-like multimeric structure) state. However, it remains unclear whether the amorphous or rodlet state is biologically functional and what external factors regulate state transition. In this study, we analyzed the self-assembly of hydrophobin RolA of Aspergillus oryzae in detail and identified factors regulating this process. Using atomic force microscopy, we observed RolA rodlet formation over time, and determined "rodlet elongation rate" and "rodlet formation frequency." Changes in these kinetic parameters in response to pH and salt concentration suggest that RolA rodlet formation is regulated by the strength of ionic interactions between RolA molecules.
Collapse
Affiliation(s)
- Nao Takahashi
- Laboratory of Applied Microbiology, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 980-8572, Japan
| | - Yuki Terauchi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Takumi Tanaka
- Laboratory of Breeding Engineering for Koji Mold, Graduate School of Engineering, Osaka University, Osaka, Osaka 565-0871, Japan
| | - Akira Yoshimi
- Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Hiroshi Yabu
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, Miyagi 980-8577, Japan
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 980-8572, Japan
| |
Collapse
|
3
|
Han J, Kawauchi M, Schiphof K, Terauchi Y, Yoshimi A, Tanaka C, Nakazawa T, Honda Y. Features of disruption mutants of genes encoding for hydrophobin Vmh2 and Vmh3 in mycelial formation and resistance to environmental stress in Pleurotus ostreatus. FEMS Microbiol Lett 2023; 370:7134070. [PMID: 37081785 DOI: 10.1093/femsle/fnad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 04/22/2023] Open
Abstract
Hydrophobins, which are small-secreted proteins with both hydrophobic and hydrophilic parts, can self-assemble into an amphiphilic film at the air-water interface, helping the fungus to form aerial hyphae. In the agaricomycete Pleurotus ostreatus, more than 20 putative hydrophobin genes have been predicted. Of these, two hydrophobin genes, vmh2 and vmh3, are predominantly expressed in the vegetative mycelium. In this study, we focused on the functions of Vmh2 and Vmh3 in vegetative mycelia. Based on the observation of the mycelial cross-section by transmission electron microscopy and the disappearance time of water droplets on the mycelial surface, Vmh2 and Vmh3 were considered essential for the maintenance of the surface hydrophobicity of the mycelium. The Δvmh3 and Δvmh2Δvmh3 strains exhibited relatively slower aerial mycelia formation on a liquid medium, and no significant alteration was observed in Δvmh2 strains. Only the Δvmh3 and Δvmh2Δvmh3 strains grew slower than the wild-type strain under stress conditions involving SDS and H2O2 on agar plates. This study revealed possible distinct roles for these hydrophobins in stress resistance. These results suggest that Agaricomycetes, including P. ostreatus, have evolved to possess multiple different hydrophobins as a means of adapting to various environments.
Collapse
Affiliation(s)
- Junxian Han
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Moriyuki Kawauchi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kim Schiphof
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yuki Terauchi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Akira Yoshimi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Chihiro Tanaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takehito Nakazawa
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yoichi Honda
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| |
Collapse
|
4
|
Han J, Kawauchi M, Terauchi Y, Yoshimi A, Tanaka C, Nakazawa T, Honda Y. Physiological function of hydrophobin Vmh3 in lignin degradation by white-rot fungus Pleurotus ostreatus. Lett Appl Microbiol 2023; 76:7120042. [PMID: 37061783 DOI: 10.1093/lambio/ovad048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/07/2023] [Accepted: 04/13/2023] [Indexed: 04/17/2023]
Abstract
Hydrophobins are small-secreted proteins comprising both hydrophobic and hydrophilic parts, that can self-assemble into an amphiphilic film at the air-liquid interface. More than 20 hydrophobin genes have been estimated in the white-rot fungus Pleurotus ostreatus. In our previous studies, three hydrophobin genes were shown to be predominantly expressed under ligninolytic conditions, and only vmh3 was downregulated in both the delignification-deficient mutant Δgat1 and Δhir1 strains. Here, we focused on the function of the hydrophobin Vmh3 to clarify its physiological role in lignin degradation. When the hyphae were observed by transmission electron microscopy, deletion of vmh3 resulted in the disappearance of black aggregates at the interface between the cell wall and outer environment. Deletion of vmh3 resulted in reduced hydrophobicity when 0.2% sodium dodecyl sulfate was dropped onto the mycelial surface. These results suggest that Vmh3 functions on the cell surface and plays a major role in mycelial hydrophobization. Furthermore, the Δvmh3 strain showed a marked delay in lignin degradation on beech wood sawdust medium, while the production of lignin-modifying enzymes was not reduced. This study demonstrated, for the first time, the possible effect of hydrophobin on lignin degradation by a white-rot fungus.
Collapse
Affiliation(s)
- Junxian Han
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Moriyuki Kawauchi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yuki Terauchi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Akira Yoshimi
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Chihiro Tanaka
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takehito Nakazawa
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yoichi Honda
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| |
Collapse
|
5
|
Terauchi Y, Tanaka T, Mitsuishi M, Yabu H, Yoshimi A, Nantani K, Abe K. Analysis of the self-assembly process of Aspergillus oryzae hydrophobin RolA by Langmuir-Blodgett method. Biosci Biotechnol Biochem 2019; 84:678-685. [PMID: 31876261 DOI: 10.1080/09168451.2019.1706443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hydrophobins are small, amphipathic proteins secreted by filamentous fungi. Hydrophobin RolA, which is produced by Aspergillus oryzae, attaches to solid surfaces, recruits the polyesterase CutL1, and consequently promotes hydrolysis of polyesters. Because this interaction requires the N-terminal, positively charged residue of RolA to be exposed on the solid surface, the orientation of RolA on the solid surface is important for recruitment. However, the process by which RolA forms the self-assembled structure at the interface remains unclear. Using the Langmuir-Blodgett technique, we analyzed the process by which RolA forms a self-assembled structure at the air-water interface and observed the structures on the hydrophobic or hydrophilic SiO2 substrates via atomic force microscopy. We found that RolA formed self-assembled films in two steps during phase transitions. We observed different assembled structures of RolA on hydrophilic and hydrophobic SiO2 substrates.
Collapse
Affiliation(s)
- Yuki Terauchi
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Takumi Tanaka
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Masaya Mitsuishi
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, Japan
| | - Hiroshi Yabu
- WPI-Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai, Japan
| | - Akira Yoshimi
- New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Japan
| | - Kei Nantani
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Keietsu Abe
- Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Japan.,Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| |
Collapse
|
6
|
Gonai M, Shigehisa A, Kigawa I, Kurasaki K, Chonan O, Matsuki T, Yoshida Y, Aida M, Hamano K, Terauchi Y. Galacto-oligosaccharides ameliorate dysbiotic Bifidobacteriaceae decline in Japanese patients with type 2 diabetes. Benef Microbes 2017; 8:705-716. [DOI: 10.3920/bm2016.0230] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Gut microbiota affects the host’s metabolism, and it is suggested that there are differences in gut microbiota composition between patients with type 2 diabetes and healthy individuals. Additionally, dysbiosis may increase the concentration of lipopolysaccharides (LPS), causing metabolic endotoxemia, which induces impaired glucose tolerance. Several studies have reported relationships between metabolic diseases and the gut microbiota; and prebiotics, such as oligosaccharides, are commonly consumed to regulate gut microbiotas in healthy individuals. Galacto-oligosaccharides (GOS) are a major prebiotic, which specifically increase Bifidobacteriaceae abundance. Recent studies have reported that Bifidobacteriaceae improved metabolic endotoxemia or impaired glucose tolerance. However, there are few studies reporting the effects of GOS on patients with type 2 diabetes. In the current study, we compared clinical parameters, faecal gut microbiota, their associated metabolic products and their components such as LPS, and LPS-binding protein (LBP) produced by the host, between patients with diabetes and healthy controls. We then assessed the effects of GOS on glycaemic control, and gut microbiotas and metabolites in patients with type 2 diabetes in a double-blind controlled manner. LBP levels were significantly higher in patients with diabetes than those of healthy subjects, which was consistent with previous reports. The abundance of Bifidobacteriaceae and the diversity of intestinal microbiota were significantly lower in patients with diabetes than in healthy subjects. Interestingly, Bifidobacteriaceae was markedly restored in patients with diabetes after consumption of GOS, whereas LBP and glucose tolerance did not improve during this short-term trial period. In the present study, we demonstrated that GOS can ameliorate dysbiosis in patients with diabetes, and continuous intake of GOS may be a promising method for managing type 2 diabetes.
Collapse
Affiliation(s)
- M. Gonai
- Department of Diabetes and Endocrinology, Kantoh Rosai Hospital, 1-1 Kizukisumiyoshi, Nakahara, Kawasaki, Kanagawa 211-8510, Japan
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa 236-0004, Japan
| | - A. Shigehisa
- Yakult Central Institute, Yakult Honsha Co., Ltd., 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
| | - I. Kigawa
- Department of Diabetes and Endocrinology, Kantoh Rosai Hospital, 1-1 Kizukisumiyoshi, Nakahara, Kawasaki, Kanagawa 211-8510, Japan
| | - K. Kurasaki
- Department of Diabetes and Endocrinology, Kantoh Rosai Hospital, 1-1 Kizukisumiyoshi, Nakahara, Kawasaki, Kanagawa 211-8510, Japan
| | - O. Chonan
- Yakult Central Institute, Yakult Honsha Co., Ltd., 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
| | - T. Matsuki
- Yakult Central Institute, Yakult Honsha Co., Ltd., 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
| | - Y. Yoshida
- Yakult Central Institute, Yakult Honsha Co., Ltd., 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
| | - M. Aida
- Yakult Central Institute, Yakult Honsha Co., Ltd., 5-11 Izumi, Kunitachi, Tokyo 186-8650, Japan
| | - K. Hamano
- Department of Diabetes and Endocrinology, Kantoh Rosai Hospital, 1-1 Kizukisumiyoshi, Nakahara, Kawasaki, Kanagawa 211-8510, Japan
| | - Y. Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa 236-0004, Japan
| |
Collapse
|
7
|
Terauchi Y, Kim YK, Tanaka T, Nanatani K, Takahashi T, Abe K. Asp30 of Aspergillus oryzae cutinase CutL1 is involved in the ionic interaction with fungal hydrophobin RolA. Biosci Biotechnol Biochem 2017; 81:1363-1368. [DOI: 10.1080/09168451.2017.1321952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Abstract
Aspergillus oryzae hydrophobin RolA adheres to the biodegradable polyester polybutylene succinate-co-adipate (PBSA) and promotes PBSA degradation by interacting with A. oryzae polyesterase CutL1 and recruiting it to the PBSA surface. In our previous studies, we found that positively charged amino acid residues (H32, K34) of RolA and negatively charged residues (E31, D142, D171) of CutL1 are important for the cooperative ionic interaction between RolA and CutL1, but some other charged residues in the triple mutant CutL1-E31S/D142S/D171S are also involved. In the present study, on the basis of the 3D-structure of CutL1, we hypothesized that D30 is also involved in the CutL1–RolA interaction. We substituted D30 with serine and performed kinetic analysis of the interaction between wild-type RolA and the single mutant CutL1-D30S or quadruple mutant CutL1-D30S/E31S/D142S/D171S by using quartz crystal microbalance. Our results indicate that D30 is a novel residue involved in the ionic interaction between RolA and CutL1.
Collapse
Affiliation(s)
- Yuki Terauchi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoon-Kyung Kim
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Takumi Tanaka
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kei Nanatani
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Toru Takahashi
- Microbial Genomics Laboratory, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Microbial Genomics Laboratory, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| |
Collapse
|
8
|
Terauchi Y, Koyama M, Cheng X, Sumi M, Riddle MC, Bolli GB, Hirose T. Glycaemic control and hypoglycaemia with insulin glargine 300 U/mL compared with glargine 100 U/mL in Japanese adults with type 2 diabetes using basal insulin plus oral anti-hyperglycaemic drugs (EDITION JP 2 randomised 12-month trial including 6-month extension). Diabetes Metab 2017; 43:446-452. [PMID: 28433560 DOI: 10.1016/j.diabet.2017.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/22/2017] [Accepted: 03/10/2017] [Indexed: 10/19/2022]
Abstract
AIMS To compare insulin glargine 300 U/mL (Gla-300) with glargine 100 U/mL (Gla-100) in Japanese adults with uncontrolled type 2 diabetes on basal insulin and oral anti-hyperglycaemic drugs over 12 months. METHODS EDITION JP 2 was a randomised, open-label, phase 3 study. Following a 6-month treatment period, participants continued receiving previously assigned once daily Gla-300 or Gla-100, plus oral anti-hyperglycaemic drugs, in a 6-month extension period. Glycaemic control, hypoglycaemia and adverse events were assessed. RESULTS The 12-month completion rate was 88% for Gla-300 and 96% for Gla-100, with comparable reasons for discontinuation. Mean HbA1c decrease from baseline to month 12 was 0.3% in both groups. Annualised rates of confirmed (≤3.9mmol/L [≤70mg/dL]) or severe hypoglycaemia were lower with Gla-300 than Gla-100 (nocturnal [00:00-05:59h]: rate ratio 0.41; 95% confidence interval: 0.18 to 0.92; anytime [24h]: rate ratio 0.64; 95% confidence interval: 0.44 to 0.94). Cumulative number of hypoglycaemic events was lower with Gla-300 than Gla-100. Adverse event profiles were comparable between treatments. CONCLUSION Over 12 months, Gla-300-treated participants achieved sustained glycaemic control and experienced less hypoglycaemia, particularly at night, versus Gla-100, supporting 6-month results.
Collapse
Affiliation(s)
- Y Terauchi
- Yokohama City University Graduate School of Medicine, Department of Endocrinology and Metabolism, 3-9 Fukuura, Kanazawa-ku, 236-0004 Yokohama, Japan.
| | - M Koyama
- Sanofi, 3-20-2 Nishi-Shinjuku, Shinjuku-ku, 163-1488 Tokyo, Japan.
| | - X Cheng
- Sanofi, 112 Jianguo Road, Chaoyang District, 100022 Beijing, China.
| | - M Sumi
- Sanofi, 3-20-2 Nishi-Shinjuku, Shinjuku-ku, 163-1488 Tokyo, Japan.
| | - M C Riddle
- Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, 97239 Portland, OR, USA.
| | - G B Bolli
- Perugia University School of Medicine, Ospedale Santa Maria della Misericordia, 06132 Perugia, Italy.
| | - T Hirose
- Toho University School of Medicine, 5 Chome-21-16 Omorinishi, Ota, 143-8540 Tokyo, Japan.
| | | |
Collapse
|
9
|
Nakamura A, Iwami D, Miyoshi H, Morita K, Taguri M, Terauchi Y, Shinohara N, Atsumi T. Impact of renal transplantation on glucose tolerance in Japanese recipients with impaired glucose tolerance. Diabet Med 2017; 34:569-576. [PMID: 27505857 DOI: 10.1111/dme.13199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/08/2016] [Indexed: 12/30/2022]
Abstract
AIMS To investigate changes in glucose tolerance, insulin secretion and insulin sensitivity in Japanese recipients before and 1 year after renal transplantation. METHODS We conducted a study of Japanese recipients without diabetes who underwent renal transplantation at Hokkaido University Hospital. A 75-g oral glucose tolerance test was performed before and 1 year after renal transplantation in these recipients. Insulin sensitivity was estimated using the Matsuda index and homeostasis model assessment of insulin resistance (HOMA-IR). Insulin secretion was evaluated based on the insulin secretion sensitivity index-2 (ISSI-2). RESULTS Of the 62 renal transplant recipients, 31 were diagnosed as having impaired glucose tolerance before transplantation. Among these 31 recipients, after 1 year, four had developed new-onset diabetes after transplantation, and nine had impaired glucose tolerance. Unexpectedly, 18 changed from impaired to normal glucose tolerance. When these recipients with impaired glucose tolerance were classified into a non-amelioration group and an amelioration group, the ISSI-2 was significantly reduced, with no significant changes in the Matsuda index or HOMA-IR, in the non-amelioration group 1 year after renal transplantation. By contrast, ISSI-2 and Matsuda index values were significantly increased, with no significant changes in HOMA-IR values in the amelioration group. CONCLUSIONS More than half of Japanese renal transplant recipients with impaired glucose tolerance had normal glucose tolerance 1 year after renal transplantation. These results suggest that an increase in insulin secretion and whole insulin sensitivity was associated with improvement in glucose tolerance in these recipients.
Collapse
Affiliation(s)
- A Nakamura
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo
| | - D Iwami
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, Sapporo
| | - H Miyoshi
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo
| | - K Morita
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, Sapporo
| | - M Taguri
- Department of Biostatistics, Yokohama City University, Yokohama
| | - Y Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - N Shinohara
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, Sapporo
| | - T Atsumi
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo
| |
Collapse
|
10
|
Terauchi Y, Koyama M, Cheng X, Takahashi Y, Riddle MC, Bolli GB, Hirose T. New insulin glargine 300 U/ml versus glargine 100 U/ml in Japanese people with type 2 diabetes using basal insulin and oral antihyperglycaemic drugs: glucose control and hypoglycaemia in a randomized controlled trial (EDITION JP 2). Diabetes Obes Metab 2016; 18:366-74. [PMID: 26662838 PMCID: PMC5066636 DOI: 10.1111/dom.12618] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/01/2015] [Accepted: 11/30/2015] [Indexed: 12/27/2022]
Abstract
AIMS To compare the efficacy and safety of insulin glargine 300 U/ml (Gla-300) with glargine 100 U/ml (Gla-100) in Japanese people with type 2 diabetes using basal insulin plus oral antihyperglycaemic drug(s) [OAD(s)]. METHODS The EDITION JP 2 study (NCT01689142) was a 6-month, multicentre, open-label, phase III study. Participants (n = 241, male 61%, mean diabetes duration 14 years, mean weight 67 kg, mean body mass index 25 kg/m(2), mean glycated haemoglobin (HbA1c) 8.02 %, mean basal insulin dose 0.24 U/kg/day) were randomized to Gla-300 or Gla-100, while continuing OAD(s). Basal insulin was titrated to target fasting self-monitored plasma glucose 4.4-5.6 mmol/l. The primary efficacy endpoint was HbA1c change over 6 months. Safety endpoints included hypoglycaemia and weight change. RESULTS Gla-300 was non-inferior to Gla-100 for HbA1c reduction [least squares (LS) mean difference 0.10 (95% confidence interval [CI] -0.08, 0.27) %]. The mean HbA1c at month 6 was 7.56 and 7.52 % with Gla-300 and Gla-100, respectively. Nocturnal confirmed (≤3.9 mmol/l) or severe hypoglycaemia risk was 38% lower with Gla-300 versus Gla-100 [relative risk 0.62 (95% CI 0.44, 0.88)]; annualized rates were 55% lower at night [rate ratio 0.45 (95% CI 0.21, 0.96)] and 36% lower at any time [24 h; rate ratio 0.64 (95% CI 0.43, 0.96)]. Severe hypoglycaemia was infrequent. A significant between-treatment difference in weight change favoured Gla-300 [LS mean difference -1.0 (95% CI -1.5, -0.5) kg; p = 0.0003]. Adverse event rates were comparable between groups. CONCLUSIONS Japanese people with type 2 diabetes using basal insulin plus OAD(s) experienced less hypoglycaemia with Gla-300 than with Gla-100, while glycaemic control did not differ.
Collapse
Affiliation(s)
- Y Terauchi
- Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | | | | | | | - M C Riddle
- Oregon Health & Science University, Portland, OR, USA
| | - G B Bolli
- Perugia University Medical School, Perugia, Italy
| | - T Hirose
- Toho University School of Medicine, Tokyo, Japan
| |
Collapse
|
11
|
Kaku K, Kadowaki T, Terauchi Y, Okamoto T, Sato A, Okuyama K, Arjona Ferreira JC, Goldstein BJ. Sitagliptin improves glycaemic excursion after a meal or after an oral glucose load in Japanese subjects with impaired glucose tolerance. Diabetes Obes Metab 2015; 17:1033-41. [PMID: 26094974 PMCID: PMC5034821 DOI: 10.1111/dom.12507] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 05/31/2015] [Accepted: 06/06/2015] [Indexed: 12/14/2022]
Abstract
AIMS To evaluate the efficacy and tolerability of sitagliptin in subjects with impaired glucose tolerance (IGT). METHODS In a double-blind, parallel-group study, 242 Japanese subjects with IGT, determined by a 75-g oral glucose tolerance test (OGTT) at week -1, were randomized (1 : 1 : 1) to placebo (n = 83), sitagliptin 25 mg (n = 82) or 50 mg (n = 77) once daily for 8 weeks. Glycaemic variables were assessed using another OGTT at week 7 and meal tolerance tests (MTTs) at weeks 0 and 8. Primary and secondary endpoints were percent change from baseline in glucose total area under the curve 0-2 h (AUC(0 -2 h)) during the MTT and OGTT, respectively. RESULTS Least squares mean percent change from baseline in glucose AUC(0 -2 h) during the MTT were -2.4, -9.5 and -11.5%, and during the OGTT were -3.7, -21.4 and -20.1% with placebo, sitagliptin 25 mg once daily, and 50 mg once daily, respectively (p < 0.001 for either sitagliptin dose vs placebo in both tests). Sitagliptin treatment enhanced early insulin response during the OGTT and decreased total insulin response, assessed as the total AUC(0 -2 h) during the MTT. Sitagliptin treatment also suppressed glucagon response during the MTT. The incidence of adverse events, including hypoglycaemia, was low and generally similar in all treatment groups. CONCLUSIONS Treatment with sitagliptin significantly reduced glucose excursions during both an MTT and an OGTT; this effect was associated with an increase in early insulin secretion after oral glucose loading as well as a blunted glucagon response during an MTT. Sitagliptin was generally well tolerated in subjects with IGT.
Collapse
Affiliation(s)
- K Kaku
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, Kurashiki, Japan
| | - T Kadowaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Y Terauchi
- Department of Endocrinology and Metabolism, Yokohama City University, Yokohama, Japan
| | | | | | | | | | | |
Collapse
|
12
|
Nakamura A, Hagiwara E, Hamai J, Taguri M, Terauchi Y. Impact of underlying diabetes and presence of lung cavities on treatment outcomes in patients with pulmonary tuberculosis. Diabet Med 2014; 31:707-13. [PMID: 24547904 DOI: 10.1111/dme.12414] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/19/2013] [Accepted: 12/17/2013] [Indexed: 01/02/2023]
Abstract
AIMS We investigated the effects of diabetes and the presence of lung cavities on treatment outcomes in patients with pulmonary tuberculosis. METHODS We conducted a retrospective review of the clinical records of all consecutive patients admitted to the Kanagawa Cardiovascular and Respiratory Centre with the diagnosis of pulmonary tuberculosis. The study outcomes examined were time to sputum culture conversion and percentage of patients with sputum culture conversion by the time 2 months of treatment, and these outcomes were compared between patients with and without diabetes. RESULTS Of the 260 patients enrolled in the study, 69 were diagnosed as having diabetes mellitus, while the remaining 191 did not have diabetes. The percentage of patients with cavities was higher in the patients with diabetes (71.0%) than in those without (45.5%; P = 0.0003). The time to sputum culture conversion was significantly longer in the patients with diabetes than in those without (P = 0.0005), and the percentage of patients with a positive sputum culture at 2 months was higher in the patients with diabetes (43.5%) than in those without (18.8%; P = 0.0001). Multivariate analyses revealed that the presence/absence of lung cavities was a more important determinant of treatment outcomes than the presence/absence of diabetes. CONCLUSIONS The presence of lung cavities was found to be a more important determinant of the treatment outcomes than that of diabetes per se in patients with pulmonary tuberculosis.
Collapse
Affiliation(s)
- A Nakamura
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | | | | | | | | |
Collapse
|
13
|
Tajima K, Nakamura A, Shirakawa J, Togashi Y, Orime K, Sato K, Inoue H, Kaji M, Sakamoto E, Ito Y, Aoki K, Nagashima Y, Atsumi T, Terauchi Y. Metformin prevents liver tumorigenesis induced by high-fat diet in C57Bl/6 mice. Am J Physiol Endocrinol Metab 2013; 305:E987-98. [PMID: 23964070 DOI: 10.1152/ajpendo.00133.2013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is increasing with the growing epidemics of obesity and diabetes. NAFLD encompasses a clinicopathologic spectrum of disease ranging from isolated hepatic steatosis to NASH, which is a more aggressive form of fatty liver disease, to cirrhosis and, finally, hepatocellular carcinoma (HCC). The exact mechanism behind the development of HCC in NASH remains unclear; however, it has been established that hepatic steatosis is the important risk factor in the development of HCC. Metformin has recently drawn attention because of its potential antitumor effect. Here, we investigated the effects of metformin on high-fat diet (HFD)-induced liver tumorigenesis, using a mouse model of NASH and liver tumor. Metformin prevented long-term HFD-induced liver tumorigenesis in C57Bl/6 mice. Of note, metformin failed to protect against liver tumorigenesis in mice that had already begun to develop NAFLD. Metformin improved short-term HFD-induced fat accumulation in the liver, associated with the suppression of adipose tissue inflammation. Collectively, these results suggest that metformin may prevent liver tumorigenesis via suppression of liver fat accumulation in the early stage, before the onset of NAFLD, which seems to be associated with a delay in the development of inflammation of the adipose tissue.
Collapse
Affiliation(s)
- K Tajima
- Department of Endocrinology and Metabolism
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Maeda H, Kubota A, Kanamori A, Tanaka Y, Terauchi Y, Matsuba I. Long-term efficacy and safety of sitagliptin in the treatment of Japanese Type 2 diabetes (ASSET-K1) to a target of HbA1c <7%. J Endocrinol Invest 2013; 36:568-73. [PMID: 23385888 DOI: 10.3275/8819] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Few studies have investigated the factors related to improvement and maintenance of glycemic control with sitagliptin in Type 2 diabetes (T2D) patients. AIM To identify factors contributing to reaching and maintaining glycated hemoglobin (HbA1c) <7% with sitagliptin in Japanese T2D patients. SUBJECTS AND METHODS This study included 1327 patients who were: taking sitagliptin as monotherapy; switched to sitagliptin; or taking sitagliptin in combination therapy. At baseline and 1, 3, 6, and 12 months after starting sitagliptin, weight, body mass index (BMI), HbA1c, fasting plasma glucose (FPG), and post-prandial plasma glucose (PPG) were measured. The subjects were divided into a group that achieved HbA1c<7% at 12 months, a poor control group (HbA1c≥8% at 12 months), and a discontinued group. Multiple regression analysis was performed to identify factors contributing to long-term control and maintenance with sitagliptin treatment. RESULTS HbA1c decreased significantly from 8.0% at baseline to 7.3%, but weight was unchanged. FPG and PPG improved significantly. The HbA1c<7% group had a significantly higher age and a signifi cant ly lower BMI at baseline than the HbA1c≥8% group and the discontinued group. On multivariate regression analysis, baseline HbA1c, baseline BMI, and Δbody weight after 12 months were significantly related to HbA1c reduction. The most common adverse event was hypoglycemia, and the most common adverse event responsible for discontinuation was constipation. CONCLUSIONS HbA1c<7.0% was achieved in 31% of T2D patients who had poor control with conventional treatment. Weight management is important for maintaining good long-term control with sitagliptin.
Collapse
Affiliation(s)
- H Maeda
- The Study Group of the Diabetes Committee, Kanagawa Physicians Association, Yokohama-city, Japan.
| | | | | | | | | | | |
Collapse
|
15
|
Takihata M, Nakamura A, Tajima K, Inazumi T, Komatsu Y, Tamura H, Yamazaki S, Kondo Y, Yamada M, Kimura M, Terauchi Y. Comparative study of sitagliptin with pioglitazone in Japanese type 2 diabetic patients: the COMPASS randomized controlled trial. Diabetes Obes Metab 2013; 15:455-62. [PMID: 23279373 DOI: 10.1111/dom.12055] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/12/2012] [Accepted: 12/15/2012] [Indexed: 11/30/2022]
Abstract
AIMS To compare the efficacy and safety of these two agents and the impact on surrogate markers related to diabetic complications in Japanese type 2 diabetic patients. METHODS In a multicenter, open-label trial, 130 patients whose diabetes had been inadequately controlled (HbA1c, 6.9-9.5%) with metformin and/or sulphonylurea were randomly assigned to a sitagliptin group (50 mg/day) or a pioglitazone group (15 mg/day) and were followed up for 24 weeks. At 16 weeks, if the patient's HbA1c level was ≥6.5%, the dose of sitagliptin or pioglitazone was increased up to 100 or 30 mg/day, respectively. Main outcome measure was the difference in the mean changes in the HbA1c level from baseline at 24 weeks between these two groups. RESULTS Of the 130 patients who were enrolled, 115 subjects (sitagliptin group: 58 patients, pioglitazone group: 57 patients) completed this trial. At 0 weeks, the mean HbA1c level was 7.47 ± 0.66% in the sitagliptin group and 7.40 ± 0.61% in the pioglitazone group. At 24 weeks, the mean changes in the HbA1c level from baseline were -0.86 ± 0.63% versus -0.58 ± 0.68% (p = 0.024). Hypoglycaemia (2 patients, 3.4% vs. 2 patients, 3.5%), gastrointestinal symptoms (3 patients, 5.2% vs. 1 patient, 1.8%) and pretibial oedema (0 patients, 0% vs. 39 patients, 68.4%, p < 0.001) were observed for 24 weeks. CONCLUSIONS Sitagliptin was not only more tolerable, but also more effective than pioglitazone in Japanese type 2 diabetic patients who had been treated with metformin and/or sulphonylurea.
Collapse
Affiliation(s)
- M Takihata
- Department of Endocrinology and Metabolism, Yokohama City University School of Medicine, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Nakamura A, Tajima K, Zolzaya K, Sato K, Inoue R, Yoneda M, Fujita K, Nozaki Y, Kubota KC, Haga H, Kubota N, Nagashima Y, Nakajima A, Maeda S, Kadowaki T, Terauchi Y. Protection from non-alcoholic steatohepatitis and liver tumourigenesis in high fat-fed insulin receptor substrate-1-knockout mice despite insulin resistance. Diabetologia 2012; 55:3382-91. [PMID: 22955994 DOI: 10.1007/s00125-012-2703-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 07/27/2012] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Epidemiological studies have revealed that obesity and diabetes mellitus are independent risk factors for the development of non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma. However, the debate continues on whether insulin resistance as such is directly associated with NASH and liver tumourigenesis. Here, we investigated the incidence of NASH and liver tumourigenesis in Irs1 ( -/- ) mice subjected to a long-term high-fat (HF) diet. Our hypothesis was that hepatic steatosis, rather than insulin resistance may be related to the pathophysiology of these conditions. METHODS Mice (8 weeks old, C57Bl/6J) were given free access to standard chow (SC) or an HF diet. The development of NASH and liver tumourigenesis was evaluated after mice had been on the above-mentioned diets for 60 weeks. Similarly, Irs1 ( -/- ) mice were also subjected to an HF diet for 60 weeks. RESULTS Long-term HF diet loading, which causes obesity and insulin resistance, was sufficient to induce NASH and liver tumourigenesis in the C57Bl/6J mice. Obesity and insulin resistance were reduced by switching mice from the HF diet to SC, which also protected these mice against the development of NASH and liver tumourigenesis. However, compared with wild-type mice fed the HF diet, Irs1 ( -/- ) mice fed the HF diet were dramatically protected against NASH and liver tumourigenesis despite the presence of severe insulin resistance and marked postprandial hyperglycaemia. CONCLUSIONS/INTERPRETATION IRS-1 inhibition might protect against HF diet-induced NASH and liver tumourigenesis, despite the presence of insulin resistance.
Collapse
Affiliation(s)
- A Nakamura
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Nakamura A, Togashi Y, Orime K, Sato K, Shirakawa J, Ohsugi M, Kubota N, Kadowaki T, Terauchi Y. Control of beta cell function and proliferation in mice stimulated by small-molecule glucokinase activator under various conditions. Diabetologia 2012; 55:1745-54. [PMID: 22456697 DOI: 10.1007/s00125-012-2521-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 02/20/2012] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS We investigated changes in the expression of genes involved in beta cell function and proliferation in mouse islets stimulated with glucokinase activator (GKA) in order to elucidate the mechanisms by which GKA stimulates beta cell function and proliferation. METHODS Islets isolated from mice were used to investigate changes in the expression of genes related to beta cell function and proliferation stimulated by GKA. In addition, Irs2 knockout (Irs2 (-/-)) mice on a high-fat diet or a high-fat diet containing GKA were used to investigate the effects of GKA on beta cell proliferation in vivo. RESULTS In wild-type mice, Irs2 and Pdx1 expression was increased by GKA. In Irs2 (-/-) mice, GKA administration increased the glucose-stimulated secretion of insulin and Pdx1 expression, but not beta cell proliferation. It was particularly noteworthy that oxidative stress inhibited the upregulation of the Irs2 and Pdx1 genes induced by GKA. Moreover, whereas neither GKA alone nor exendin-4 alone upregulated the expression of Irs2 and Pdx1 in the islets of db/db mice, prior administration of exendin-4 to the mice caused GKA to increase the expression of these genes. CONCLUSIONS/INTERPRETATION GKA-stimulated IRS2 production affected beta cell proliferation but not beta cell function. Oxidative stress diminished the effects of GKA on the changes in expression of genes involved in beta cell function and proliferation. A combination of GKA and an incretin-related agent might therefore be effective in therapy.
Collapse
Affiliation(s)
- A Nakamura
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Ikawa T, Nishiyama T, Shigeta T, Mohri S, Morita S, Takayanagi SI, Terauchi Y, Morikawa Y, Takagi A, Ishikawa Y, Fujii S, Kita Y, Akai S. ortho-Selective Nucleophilic Addition of Primary Amines to Silylbenzynes: Synthesis of 2-Silylanilines. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201100360] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
19
|
Ikawa T, Nishiyama T, Shigeta T, Mohri S, Morita S, Takayanagi SI, Terauchi Y, Morikawa Y, Takagi A, Ishikawa Y, Fujii S, Kita Y, Akai S. ortho-Selective Nucleophilic Addition of Primary Amines to Silylbenzynes: Synthesis of 2-Silylanilines. Angew Chem Int Ed Engl 2011; 50:5674-7. [DOI: 10.1002/anie.201100360] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 03/28/2011] [Indexed: 11/09/2022]
|
20
|
Mihara Y, Matsumura T, Terauchi Y, Akiba M, Arai S, Nishida A. Asymmetric Synthesis of Hydroisoquinoline Derivatives, a Key Intermediate for Manzamine Synthesis, by Diels–Alder Reaction Using 4-Amino-2-siloxybutadiene. BCSJ 2009. [DOI: 10.1246/bcsj.82.1520] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
21
|
Takamoto I, Terauchi Y, Kubota N, Ohsugi M, Ueki K, Kadowaki T. Crucial role of insulin receptor substrate-2 in compensatory beta-cell hyperplasia in response to high fat diet-induced insulin resistance. Diabetes Obes Metab 2008; 10 Suppl 4:147-56. [PMID: 18834442 DOI: 10.1111/j.1463-1326.2008.00951.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In type 2 diabetes, there is a defect in the regulation of functional beta-cell mass to overcome high-fat (HF) diet-induced insulin resistance. Many signals and pathways have been implicated in beta-cell function, proliferation and apoptosis. The co-ordinated regulation of functional beta-cell mass by insulin signalling and glucose metabolism under HF diet-induced insulin-resistant conditions is discussed in this article. Insulin receptor substrate (IRS)-2 is one of the two major substrates for the insulin signalling. Interestingly, IRS-2 is involved in the regulation of beta-cell proliferation, as has been demonstrated using knockout mice models. On the other hand, in an animal model for human type 2 diabetes with impaired insulin secretion because of insufficiency of glucose metabolism, decreased beta-cell proliferation was observed in mice with beta-cell-specific glucokinase haploinsufficiency (Gck(+/) (-)) fed a HF diet without upregulation of IRS-2 in beta-cells, which was reversed by overexpression of IRS-2 in beta-cells. As to the mechanism underlying the upregulation of IRS-2 in beta-cells, glucose metabolism plays an important role independently of insulin, and phosphorylation of cAMP response element-binding protein triggered by calcium-dependent signalling is the critical pathway. Downstream from insulin signalling via IRS-2 in beta-cells, a reduction in FoxO1 nuclear exclusion contributes to the insufficient proliferative response of beta-cells to insulin resistance. These findings suggest that IRS-2 is critical for beta-cell hyperplasia in response to HF diet-induced insulin resistance.
Collapse
Affiliation(s)
- I Takamoto
- Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
22
|
Abstract
AIM alpha-Glucosidase inhibitors (alphaGIs) primarily modify postprandial plasma glucose levels and should be taken just before meals. We previously demonstrated that a single administration of miglitol within 30 min after the start of a meal was equally effective as when administered just before a meal. We here compared pre- vs. postmeal administration of miglitol for 3 months in type 2 diabetic patients. METHODS Thirty-one type 2 diabetic outpatients who had never been treated with insulin injections or alphaGIs were randomized to two groups: patients in group A were asked to take miglitol just before meals, while patients in group B were asked to take miglitol after meals. We measured 1,5-anhydroglucitol (1,5-AG) and HbA(1C) levels in these patients. RESULTS The administration of miglitol after meals for a 3-month period decreased HbA(1C) and increased 1,5-AG levels to the same extent as when administered just before meals. The incidence of adverse effects seemed to be unrelated to the timing of the miglitol administration. CONCLUSIONS Our results suggest that if patients have difficulty remembering to take miglitol just before meal, they should be instructed to take the medicine together with other medicine(s) after the meal; this instruction may improve the treatment compliance of diabetic patients.
Collapse
|
23
|
Yoneda M, Saito S, Ikeda T, Fujita K, Mawatari H, Kirikoshi H, Inamori M, Nozaki Y, Akiyama T, Takahashi H, Abe Y, Kubota K, Iwasaki T, Terauchi Y, Togo S, Nakajima A. Hepatitis C virus directly associates with insulin resistance independent of the visceral fat area in nonobese and nondiabetic patients. J Viral Hepat 2007; 14:600-7. [PMID: 17697011 DOI: 10.1111/j.1365-2893.2006.00836.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Insulin resistance (IR) is known to be associated with the visceral adipose tissue area. Elucidation of the relationship between hepatitis C virus (HCV) and IR is of great clinical relevance, because IR promotes liver fibrosis. In this study, we tested the hypothesis that HCV infection by itself may promote IR. We prospectively evaluated 47 patients with chronic HCV infection who underwent liver biopsy. Patients with obesity, type 2 diabetes mellitus (DM), or a history of alcohol consumption were excluded. IR was estimated by calculation of the modified homeostasis model of insulin resistance (HOMA-IR) index. Abdominal fat distribution was determined by computed tomography. Fasting blood glucose levels were within normal range in all the patients. The results of univariate analysis revealed a significant correlation between the quantity of HCV-RNA and the HOMA-IR (r = 0.368, P = 0.0291). While a significant correlation between the visceral adipose tissue area and the HOMA-IR was also observed in the 97 control, nondiabetic, non-HCV-infected patients (r = 0.398, P < 0.0001), no such significant correlation between the visceral adipose tissue area and the HOMA-IR (r = 0.124, P = 0.496) was observed in the patients with HCV infection. Multiple regression analysis with adjustment for age, gender and visceral adipose tissue area revealed a significant correlation between the HCV-RNA and the HOMA-IR (P = 0.0446). HCV is directly associated with IR in a dose-dependent manner, independent of the visceral adipose tissue area. This is the first report to demonstrate the direct involvement of HCV and IR in patients with chronic HCV infection.
Collapse
Affiliation(s)
- M Yoneda
- Division of Gastroenterology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Kubota T, Moroi M, Kubota N, Terauchi Y, Kamata K, Yajima S, Ishikawa M, Namiki A, Kadowaki T. 3P-0712 Heterozygous PPAR γ deficient mice showed impaired endothelium-dependent vascular relaxation and increased neointima formation in response to cuff injury. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90931-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
25
|
Setoguchi K, Misaki Y, Terauchi Y, Yamauchi T, Kawahata K, Kadowaki T, Yamamoto K. Peroxisome proliferator-activated receptor-gamma haploinsufficiency enhances B cell proliferative responses and exacerbates experimentally induced arthritis. J Clin Invest 2001; 108:1667-75. [PMID: 11733562 PMCID: PMC200985 DOI: 10.1172/jci13202] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Peroxisome proliferator-activated receptor-gamma (PPAR gamma) controls adipogenesis and glucose metabolism. It was reported recently that PPAR gamma activation by its agonistic ligands modifies lymphocyte function. Since synthetic ligands are known to exert their effect via PPAR gamma-dependent and -independent pathways, we examined the physiological role of PPAR gamma in lymphocytes by using heterozygote mutant mice in which one allele of PPAR gamma is deleted (PPAR gamma(+/-)). In contrast to T cells, which did not exhibit a significant difference, B cells from PPAR gamma(+/-) showed an enhanced proliferative response to stimulation by either lipopolysaccharide or cross-linking of antigen receptors. Dysregulation of the NF-kappa B pathway in B cells from PPAR gamma(+/-) was indicated by spontaneous NF-kappa B activation, as well as increased I kappa B alpha phosphorylation and gel-shift activity following LPS stimulation. Mice primed with either ovalbumin or methylated BSA also showed enhanced antigen-specific immune response of both T and B cells, an immunological abnormality that exacerbated antigen-induced arthritis. These findings indicate that PPAR gamma plays a critical role in the control of B cell response and imply a role in diseases in which B cell hyperreactivity is involved, such as arthritis and autoimmunity.
Collapse
Affiliation(s)
- K Setoguchi
- Department of Allergy and Rheumatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
26
|
Yamauchi T, Kamon J, Waki H, Murakami K, Motojima K, Komeda K, Ide T, Kubota N, Terauchi Y, Tobe K, Miki H, Tsuchida A, Akanuma Y, Nagai R, Kimura S, Kadowaki T. The mechanisms by which both heterozygous peroxisome proliferator-activated receptor gamma (PPARgamma) deficiency and PPARgamma agonist improve insulin resistance. J Biol Chem 2001; 276:41245-54. [PMID: 11533050 DOI: 10.1074/jbc.m103241200] [Citation(s) in RCA: 490] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peroxisome proliferator-activated receptor (PPAR) gamma is a ligand-activated transcription factor and a member of the nuclear hormone receptor superfamily that is thought to be the master regulator of fat storage; however, the relationship between PPARgamma and insulin sensitivity is highly controversial. We show here that supraphysiological activation of PPARgamma by PPARgamma agonist thiazolidinediones (TZD) markedly increases triglyceride (TG) content of white adipose tissue (WAT), thereby decreasing TG content of liver and muscle, leading to amelioration of insulin resistance at the expense of obesity. Moderate reduction of PPARgamma activity by heterozygous PPARgamma deficiency decreases TG content of WAT, skeletal muscle, and liver due to increased leptin expression and increase in fatty acid combustion and decrease in lipogenesis, thereby ameliorating high fat diet-induced obesity and insulin resistance. Moreover, although heterozygous PPARgamma deficiency and TZD have opposite effects on total WAT mass, heterozygous PPARgamma deficiency decreases lipogenesis in WAT, whereas TZD stimulate adipocyte differentiation and apoptosis, thereby both preventing adipocyte hypertrophy, which is associated with alleviation of insulin resistance presumably due to decreases in free fatty acids, and tumor necrosis factor alpha, and up-regulation of adiponectin, at least in part. We conclude that, although by different mechanisms, both heterozygous PPARgamma deficiency and PPARgamma agonist improve insulin resistance, which is associated with decreased TG content of muscle/liver and prevention of adipocyte hypertrophy.
Collapse
Affiliation(s)
- T Yamauchi
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Tobe K, Suzuki R, Aoyama M, Yamauchi T, Kamon J, Kubota N, Terauchi Y, Matsui J, Akanuma Y, Kimura S, Tanaka J, Abe M, Ohsumi J, Nagai R, Kadowaki T. Increased expression of the sterol regulatory element-binding protein-1 gene in insulin receptor substrate-2(-/-) mouse liver. J Biol Chem 2001; 276:38337-40. [PMID: 11546755 DOI: 10.1074/jbc.c100160200] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin receptor substrate (IRS)-2(-/-) mice develop diabetes because of insulin resistance in the liver and failure to undergo beta-cell hyperplasia. Here we show by DNA chip microarray analysis that expression of the sterol regulatory element-binding protein (SREBP)-1 gene, a downstream target of insulin, was paradoxically increased in 16-week-old IRS-2(-/-) mouse liver, where insulin-mediated intracellular signaling events were substantially attenuated. The expression of SREBP-1 downstream genes, such as the spot 14, ATP citrate-lyase, and fatty acid synthase genes, was also increased. Increased liver triglyceride content in IRS-2(-/-) mice assures the physiological importance of SREBP-1 gene induction. IRS-2(-/-) mice showed leptin resistance; low dose leptin administration, enough to reduce food intake and body weight in wild-type mice, failed to do so in IRS-2(-/-) mice. Interestingly, high dose leptin administration reduced SREBP-1 expression in IRS-2(-/-) mouse liver. Thus, IRS-2 gene disruption results in leptin resistance, causing an SREBP-1 gene induction, obesity, fatty liver, and diabetes.
Collapse
Affiliation(s)
- K Tobe
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Yamauchi T, Waki H, Kamon J, Murakami K, Motojima K, Komeda K, Miki H, Kubota N, Terauchi Y, Tsuchida A, Tsuboyama-Kasaoka N, Yamauchi N, Ide T, Hori W, Kato S, Fukayama M, Akanuma Y, Ezaki O, Itai A, Nagai R, Kimura S, Tobe K, Kagechika H, Shudo K, Kadowaki T. Inhibition of RXR and PPARgamma ameliorates diet-induced obesity and type 2 diabetes. J Clin Invest 2001; 108:1001-13. [PMID: 11581301 PMCID: PMC200951 DOI: 10.1172/jci12864] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2001] [Accepted: 08/21/2001] [Indexed: 01/01/2023] Open
Abstract
PPARgamma is a ligand-activated transcription factor and functions as a heterodimer with a retinoid X receptor (RXR). Supraphysiological activation of PPARgamma by thiazolidinediones can reduce insulin resistance and hyperglycemia in type 2 diabetes, but these drugs can also cause weight gain. Quite unexpectedly, a moderate reduction of PPARgamma activity observed in heterozygous PPARgamma-deficient mice or the Pro12Ala polymorphism in human PPARgamma, has been shown to prevent insulin resistance and obesity induced by a high-fat diet. In this study, we investigated whether functional antagonism toward PPARgamma/RXR could be used to treat obesity and type 2 diabetes. We show herein that an RXR antagonist and a PPARgamma antagonist decrease triglyceride (TG) content in white adipose tissue, skeletal muscle, and liver. These inhibitors potentiated leptin's effects and increased fatty acid combustion and energy dissipation, thereby ameliorating HF diet-induced obesity and insulin resistance. Paradoxically, treatment of heterozygous PPARgamma-deficient mice with an RXR antagonist or a PPARgamma antagonist depletes white adipose tissue and markedly decreases leptin levels and energy dissipation, which increases TG content in skeletal muscle and the liver, thereby leading to the re-emergence of insulin resistance. Our data suggested that appropriate functional antagonism of PPARgamma/RXR may be a logical approach to protection against obesity and related diseases such as type 2 diabetes.
Collapse
MESH Headings
- 3T3 Cells
- Adipose Tissue/metabolism
- Animals
- Benzhydryl Compounds
- Benzoates/metabolism
- Benzoates/pharmacology
- Biphenyl Compounds/metabolism
- Biphenyl Compounds/pharmacology
- Diabetes Mellitus, Type 2/metabolism
- Epoxy Compounds/metabolism
- Epoxy Compounds/pharmacology
- Fatty Acids/metabolism
- Hyperglycemia/etiology
- Hyperglycemia/metabolism
- Hypoglycemic Agents/metabolism
- Hypoglycemic Agents/pharmacology
- Insulin Resistance
- Leptin/metabolism
- Mice
- Mice, Knockout
- Nicotinic Acids/metabolism
- Nicotinic Acids/pharmacology
- Obesity/metabolism
- Receptors, Adrenergic, beta-3/metabolism
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Retinoic Acid/agonists
- Receptors, Retinoic Acid/antagonists & inhibitors
- Receptors, Retinoic Acid/metabolism
- Retinoid X Receptors
- Rosiglitazone
- Tetrahydronaphthalenes/metabolism
- Tetrahydronaphthalenes/pharmacology
- Thiazoles/metabolism
- Thiazoles/pharmacology
- Thiazolidinediones
- Transcription Factors/agonists
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/metabolism
Collapse
Affiliation(s)
- T Yamauchi
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Yamauchi T, Kamon J, Waki H, Terauchi Y, Kubota N, Hara K, Mori Y, Ide T, Murakami K, Tsuboyama-Kasaoka N, Ezaki O, Akanuma Y, Gavrilova O, Vinson C, Reitman ML, Kagechika H, Shudo K, Yoda M, Nakano Y, Tobe K, Nagai R, Kimura S, Tomita M, Froguel P, Kadowaki T. The fat-derived hormone adiponectin reverses insulin resistance associated with both lipoatrophy and obesity. Nat Med 2001; 7:941-6. [PMID: 11479627 DOI: 10.1038/90984] [Citation(s) in RCA: 3418] [Impact Index Per Article: 148.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adiponectin is an adipocyte-derived hormone. Recent genome-wide scans have mapped a susceptibility locus for type 2 diabetes and metabolic syndrome to chromosome 3q27, where the gene encoding adiponectin is located. Here we show that decreased expression of adiponectin correlates with insulin resistance in mouse models of altered insulin sensitivity. Adiponectin decreases insulin resistance by decreasing triglyceride content in muscle and liver in obese mice. This effect results from increased expression of molecules involved in both fatty-acid combustion and energy dissipation in muscle. Moreover, insulin resistance in lipoatrophic mice was completely reversed by the combination of physiological doses of adiponectin and leptin, but only partially by either adiponectin or leptin alone. We conclude that decreased adiponectin is implicated in the development of insulin resistance in mouse models of both obesity and lipoatrophy. These data also indicate that the replenishment of adiponectin might provide a novel treatment modality for insulin resistance and type 2 diabetes.
Collapse
Affiliation(s)
- T Yamauchi
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Matsuda M, Mizuki Y, Terauchi Y. Simultaneous determination of the histamine H1-receptor antagonist ebastine and its two metabolites, carebastine and hydroxyebastine, in human plasma using high-performance liquid chromatography. J Chromatogr B Biomed Sci Appl 2001; 757:173-9. [PMID: 11419742 DOI: 10.1016/s0378-4347(00)00494-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ebastine (CAS 90729-43-4) is an antiallergic agent which selectively and potently blocks histamine H1-receptors in vivo. A simple and sensitive high-performance liquid chromatography (HPLC) method is described for the simultaneous determination of ebastine and its two oxidized metabolites, carebastine (CAS 90729-42-3) and hydroxyebastine (M-OH), in human plasma. After a pretreatment of plasma sample by solid-phase extraction, ebastine and its metabolites were analyzed on an HPLC system with ultraviolet detection at 254 nm. Chromatography was performed on a cyano column (250x4.0 mm I.D.) at 40 degrees C with the mobile phase of acetonitrile-methanol-0.012 M ammonium acetate buffer (20:30:48, v/v/v) at a flow rate of 1.2 ml/min. Accurate determinations were possible over the concentration range of 3-1000 ng/ml for the three compounds using 1 ml plasma samples. The intra- and inter-day assay accuracy of this method were within 100+/-15% of nominal values and the precision did not exceed 12.4% of relative standard deviation. The lower limits of quantitation were 3 ng/ml for ebastine and its metabolites in human plasma. This method was satisfactorily applied to the determination of ebastine and its two oxidized metabolites in human plasma after oral administration of ebastine.
Collapse
Affiliation(s)
- M Matsuda
- Department of Pharmacokinetics, Dainippon Pharmaceutical Co. Ltd., Osaka, Japan.
| | | | | |
Collapse
|
31
|
Hashizume T, Mise M, Matsumoto S, Terauchi Y, Fujii T, Imaoka S, Funae Y, Kamataki T, Miyazaki H. A novel cytochrome P450 enzyme responsible for the metabolism of ebastine in monkey small intestine. Drug Metab Dispos 2001; 29:798-805. [PMID: 11353747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
Small intestinal microsomes of cynomolgus monkeys were found to catalyze hydroxylation and dealkylation of an H(1)-antihistamine prodrug, ebastine. To identify the main enzyme responsible for ebastine hydroxylation, which has been hitherto unknown, we purified two cytochrome P450 isoforms, named P450 MI-2 and P450 MI-3, from the intestinal microsomes on the basis of the hydroxylation activity. P450 MI-2 and P450 MI-3 showed the respective apparent molecular weights of 56,000 and 53,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The internal amino acid sequence of P450 MI-2 had high similarity with those of human CYP4F2, CYP4F3, and CYP4F8. The first 27 amino acid residues of P450 MI-3 were highly homologous with those of monkey CYP3A8 and human CYP3A4/5/7. Furthermore, P450 MI-2 and P450 MI-3 were recognized by anti-CYP4F and anti-CYP3A antibodies, respectively, in immunoblot analysis and catalyzed leukotriene B(4) omega-hydroxylation and testosterone 6beta-hydroxylation, which are known to be mediated by CYP4F and CYP3A, respectively. Although both enzymes had ebastine hydroxylation activity, the V(max) value of P450 MI-2 was much higher than that of P450 MI-3 (37.0 versus 0.406 nmol/min/nmol of P450), and the former K(M) (5.1 microM) was smaller than the latter K(M) (10 microM). Anti-CYP4F antibody inhibited the hydroxylation in small intestinal microsomes strongly (70%), but anti-CYP3A antibody did not. These results indicate that P450 MI-2 belongs to the CYP4F subfamily and is mainly responsible for hydroxylation of ebastine in monkey small intestinal microsomes. This suggests that the small intestinal CYP4F enzyme, P450 MI-2, can play an important role in the metabolism of drugs given orally.
Collapse
Affiliation(s)
- T Hashizume
- Developmental Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Tsuji Y, Kaburagi Y, Terauchi Y, Satoh S, Kubota N, Tamemoto H, Kraemer FB, Sekihara H, Aizawa S, Akanuma Y, Tobe K, Kimura S, Kadowaki T. Subcellular localization of insulin receptor substrate family proteins associated with phosphatidylinositol 3-kinase activity and alterations in lipolysis in primary mouse adipocytes from IRS-1 null mice. Diabetes 2001; 50:1455-63. [PMID: 11375348 DOI: 10.2337/diabetes.50.6.1455] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To clarify the roles of insulin receptor substrate (IRS) family proteins in phosphatidylinositol (PI) 3-kinase activation and insulin actions in adipocytes, we investigated the intracellular localization of IRS family proteins and PI 3-kinase activation in response to insulin by fractionation of mouse adipocytes from wild-type and IRS-1 null mice. In adipocytes from wild-type mice, tyrosine-phosphorylated IRS-1 and IRS-2, which were found to associate with PI 3-kinase in response to insulin, were detected in the plasma membrane (PM) and low-density microsome (LDM) fractions. By contrast, tyrosine-phosphorylated IRS-3 (pp60), which was found to associate with PI 3-kinase, was predominantly localized in the PM fraction. In adipocytes from IRS-1-null mice, insulin-stimulated PI 3-kinase activity in anti-phosphotyrosine (alphaPY) immunoprecipitates in the LDM fraction was almost exclusively mediated via IRS-2 and was reduced to 25%; however, insulin-stimulated PI 3-kinase activity in the PM fraction was primarily mediated via IRS-3 and was reduced to 60%. To determine the potential functional impact of the distinct subcellular localization of IRSs and associating PI 3-kinase activity on adipocyte-specific metabolic actions, we examined lipolysis in IRS-1 null mice. The level of isoproterenol-induced lipolysis was increased 5.1-fold in adipocytes from IRS-1 null mice as compared with wild-type mice. Moreover, hormone-sensitive lipase (HSL) protein was increased 4.3-fold in adipocytes from IRS-1-null mice compared with wild-type mice, and HSL mRNA expression was also increased. The antilipolytic effect of insulin in IRS-1 null adipocytes, however, was comparable to that in wild-type mice. Thus, discordance between these two insulin actions as well as the transcriptional and translational effect (HSL mRNA and protein regulation) and the PM effect (antilipolysis) of insulin may be explained by distinct roles of both PI 3-kinase activity associated with IRS-1/IRS-2 and PI 3-kinase activity associated with IRS-3 in insulin actions related to their subcellular localization.
Collapse
Affiliation(s)
- Y Tsuji
- Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, 7-3-1. Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Miki H, Yamauchi T, Suzuki R, Komeda K, Tsuchida A, Kubota N, Terauchi Y, Kamon J, Kaburagi Y, Matsui J, Akanuma Y, Nagai R, Kimura S, Tobe K, Kadowaki T. Essential role of insulin receptor substrate 1 (IRS-1) and IRS-2 in adipocyte differentiation. Mol Cell Biol 2001; 21:2521-32. [PMID: 11259600 PMCID: PMC86884 DOI: 10.1128/mcb.21.7.2521-2532.2001] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
To investigate the role of insulin receptor substrate 1 (IRS-1) and IRS-2, the two ubiquitously expressed IRS proteins, in adipocyte differentiation, we established embryonic fibroblast cells with four different genotypes, i.e., wild-type, IRS-1 deficient (IRS-1(-/-)), IRS-2 deficient (IRS-2(-/-)), and IRS-1 IRS-2 double deficient (IRS-1(-/-) IRS-2(-/-)), from mouse embryos of the corresponding genotypes. The abilities of IRS-1(-/-) cells and IRS-2(-/-) cells to differentiate into adipocytes are approximately 60 and 15%, respectively, lower than that of wild-type cells, at day 8 after induction and, surprisingly, IRS-1(-/-) IRS-2(-/-) cells have no ability to differentiate into adipocytes. The expression of CCAAT/enhancer binding protein alpha (C/EBPalpha) and peroxisome proliferator-activated receptor gamma (PPARgamma) is severely decreased in IRS-1(-/-) IRS-2(-/-) cells at both the mRNA and the protein level, and the mRNAs of lipoprotein lipase and adipocyte fatty acid binding protein are severely decreased in IRS-1(-/-) IRS-2(-/-) cells. Phosphatidylinositol 3-kinase (PI 3-kinase) activity that increases during adipocyte differentiation is almost completely abolished in IRS-1(-/-) IRS-2(-/-) cells. Treatment of wild-type cells with a PI 3-kinase inhibitor, LY294002, markedly decreases the expression of C/EBPalpha and PPARgamma, a result which is associated with a complete block of adipocyte differentiation. Moreover, histologic analysis of IRS-1(-/-) IRS-2(-/-) double-knockout mice 8 h after birth reveals severe reduction in white adipose tissue mass. Our results suggest that IRS-1 and IRS-2 play a crucial role in the upregulation of the C/EBPalpha and PPARgamma expression and adipocyte differentiation.
Collapse
Affiliation(s)
- H Miki
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Hashizume T, Imaoka S, Hiroi T, Terauchi Y, Fujii T, Miyazaki H, Kamataki T, Funae Y. cDNA cloning and expression of a novel cytochrome p450 (cyp4f12) from human small intestine. Biochem Biophys Res Commun 2001; 280:1135-41. [PMID: 11162645 DOI: 10.1006/bbrc.2000.4238] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A cDNA encoding a novel human CYP4F enzyme (designated CYP4F12) was cloned by PCR from a human small intestine cDNA library. RT-PCR analysis demonstrated that CYP4F12 is expressed in human small intestine and liver. This cDNA contains an entire coding region of a 524-amino-acid protein that is 81.7, 78.3, and 78.2% identical to CYP4F2, CYP4F3, and CYP4F8, respectively. When expressed in Saccharomyces cerevisiae, the P450 catalyzes leukotriene B(4) omega-hydroxylation and arachidonic acid omega-hydroxylation, typical reactions of CYP4F isoforms. Their activity levels are, however, much lower than those of CYP4F2. Interestingly, CYP4F12 catalyzes the hydroxylation of the antihistamine ebastine with significantly higher catalytic activity relative to CYP4F2 (385 vs 5 pmol/min/nmol P450). These results indicate that CYP4F12 has a different profile of substrate specificity from other CYP4F isoforms, enzymes responsible for metabolizing endogenous autacoids, therefore suggesting that it may play an important role in xenobiotic biotransformation in the human small intestine.
Collapse
Affiliation(s)
- T Hashizume
- Developmental Research Laboratories, Dainippon Pharmaceutical Company, Ltd., 33-94 Enoki-cho, Suita, Osaka, 564-0053, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Nakajima A, Wada K, Miki H, Kubota N, Nakajima N, Terauchi Y, Ohnishi S, Saubermann LJ, Kadowaki T, Blumberg RS, Nagai R, Matsuhashi N. Endogenous PPAR gamma mediates anti-inflammatory activity in murine ischemia-reperfusion injury. Gastroenterology 2001; 120:460-9. [PMID: 11159886 DOI: 10.1053/gast.2001.21191] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a nuclear receptor whose activation has been linked to several physiologic pathways including those related to the regulation of intestinal inflammation. We sought to determine whether PPAR gamma could function as an endogenous anti-inflammatory pathway in a murine model of intestinal ischemia-reperfusion (I/R) injury. METHODS PPAR gamma-deficient and wild-type mice were examined for their response to I/R procedure. Treatment with a PPAR gamma-specific ligand was also performed. RESULTS In a murine model of intestinal I/R injury, we observed more severe injury in PPAR gamma-deficient mice and protection against local and remote tissue injury in mice treated with a PPAR gamma-activating ligand, BRL-49653. Activation of PPAR gamma resulted in down-regulation of intercellular adhesion molecule 1 expression by intestinal endothelium and tissue tumor necrosis factor alpha messenger RNA levels most likely by inhibition of the NF-kappa B pathway. CONCLUSIONS These data strongly suggest that an endogenous PPAR gamma pathway exists in tissues that may be amenable to therapeutic manipulation in I/R-related injuries.
Collapse
Affiliation(s)
- A Nakajima
- Gastroenterology Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Hara K, Kubota N, Tobe K, Terauchi Y, Miki H, Komeda K, Tamemoto H, Yamauchi T, Hagura R, Ito C, Akanuma Y, Kadowaki T. The role of PPARgamma as a thrifty gene both in mice and humans. Br J Nutr 2000; 84 Suppl 2:S235-9. [PMID: 11242476 DOI: 10.1079/096582197388608] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The biological role of peroxisome proliferator-activated receptor gamma (PPARgamma) was investigated by gene targeting and case-control study of the Pro12Ala PPARgamma2 polymorphism. Homozygous PPARgamma-deficient embryos died at 10.5-11.5 days post conception (dpc) due to placental dysfunction. Heterozygous PPARgamma-deficient mice were protected from the development of insulin resistance due to adipocyte hypertrophy under a high-fat diet, whose phenotypes were abrogated by PPARgamma agonist treatment. Heterozygous PPARgamma-deficient mice showed overexpression and hypersecretion of leptin despite the smaller size of adipocytes and decreased fat mass, which may explain these phenotypes at least in part. This study reveals a hitherto unpredicted role for PPARgamma in high-fat diet-induced obesity due to adipocyte hypertrophy and insulin resistance, which requires both alleles of PPARgamma. A Pro12Ala polymorphism has been detected in the human PPARgamma2 gene. Since this amino acid substitution may cause a reduction in the transcriptional activity of PPARgamma, this polymorphism may be associated with decreased insulin resistance and decreased risk of type 2 diabetes. To investigate this hypothesis, we performed a case-control study of the Pro12Ala PPARgamma2 polymorphism. In an obese group, subjects with Ala12 were more insulin sensitive than those without. The frequency of Ala12 was significantly lower in the diabetic group, suggesting that this polymorphism protects against type 2 diabetes. These results revealed that in both mice and humans, PPARgamma is a thrifty gene mediating type 2 diabetes.
Collapse
Affiliation(s)
- K Hara
- Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Andrikopoulos S, Verchere CB, Terauchi Y, Kadowaki T, Kahn SE. beta-cell glucokinase deficiency and hyperglycemia are associated with reduced islet amyloid deposition in a mouse model of type 2 diabetes. Diabetes 2000; 49:2056-62. [PMID: 11118007 DOI: 10.2337/diabetes.49.12.2056] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Type 2 diabetes is characterized by impaired beta-cell function, hyperglycemia, and islet amyloid deposition. The primary constituent of islet amyloid is the 37-amino acid beta-cell product called islet amyloid polypeptide (IAPP) or amylin. To study mechanisms of islet amyloid formation, we developed a transgenic mouse model that produces and secretes the amyloidogenic human IAPP (hIAPP) molecule and have shown that 81% of male transgenic mice develop islet amyloid after 14 months on a high-fat diet. To test whether impaired beta-cell function and hyperglycemia could enhance islet amyloid formation, we cross-bred our hIAPP transgenic mice with beta-cell glucokinase-knockout mice (GKKO) that have impaired glucose-mediated insulin secretion and fasting hyperglycemia. The resulting new (hIAPPxGKKO) line of mice had higher basal plasma glucose concentrations than the hIAPP transgenic mice at 3, 6, and 12 months of age (P < 0.05), as did GKKO mice compared with hIAPP transgenic mice at 6 and 12 months of age (P < 0.05). Basal plasma immunoreactive insulin (IRI) levels were lower in hIAPP x GKKO mice than in hIAPP transgenic mice at 6 months of age (P < 0.05). The area under the glucose curve in response to an intraperitoneal glucose challenge (1 g/kg body weight) was larger in hIAPPxGKKO mice than in hIAPP transgenic mice at 3, 6, and 12 months of age (P < 0.005) and in GKKO mice compared with hIAPP transgenic mice at 6 and 12 months of age (P < 0.005). The area under the IRI curve was lower in hIAPPxGKKO mice at 6 and 12 months of age (P < 0.05) than in hIAPP transgenic mice and in GKKO mice compared with hIAPP transgenic mice at 12 months of age (P < 0.05). Despite the presence of hyperglycemia, hIAPPxGKKO mice had a lower incidence (4 of 17 vs. 12 of 19, P < 0.05) and amount (0.40 +/- 0.24 vs. 1.2 +/- 0.3 arbitrary units, P < 0.05) of islet amyloid than hIAPP transgenic mice had. As expected, no islet amyloid was observed in GKKO mice lacking the hIAPP transgene (0 of 13). There was no difference in pancreatic content of IRI and hIAPP among the three groups of mice. Thus, despite the presence of impaired islet function and hyperglycemia, hIAPPxGKKO mice had a decreased incidence and quantity of islet amyloid. Therefore, our data suggest that impaired beta-cell glucose metabolism or hyperglycemia are not likely to contribute to islet amyloid formation in diabetes. Furthermore, this finding may explain the lack of progression of glycemia in patients with maturity-onset diabetes of the young.
Collapse
Affiliation(s)
- S Andrikopoulos
- Department of Medicine, University of Washington and the Veterans Affairs Puget Sound Health Care System, Seattle 98108, USA
| | | | | | | | | |
Collapse
|
38
|
Kubota N, Tobe K, Terauchi Y, Eto K, Yamauchi T, Suzuki R, Tsubamoto Y, Komeda K, Nakano R, Miki H, Satoh S, Sekihara H, Sciacchitano S, Lesniak M, Aizawa S, Nagai R, Kimura S, Akanuma Y, Taylor SI, Kadowaki T. Disruption of insulin receptor substrate 2 causes type 2 diabetes because of liver insulin resistance and lack of compensatory beta-cell hyperplasia. Diabetes 2000; 49:1880-9. [PMID: 11078455 DOI: 10.2337/diabetes.49.11.1880] [Citation(s) in RCA: 399] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To investigate the role of insulin receptor substrate (IRS)-2 in vivo, we generated IRS-2-deficient mice by gene targeting. Although homozygous IRS-2-deficient mice (IRS-2-/- mice) had a body weight similar to wild-type mice, they progressively developed type 2 diabetes at 10 weeks. IRS-2-/- mice showed insulin resistance and a defect in the insulin-stimulated signaling pathway in liver but not in skeletal muscle. Despite insulin resistance, the amount of beta-cells was reduced to 83% of that in wild-type mice, which was in marked contrast to the 85% increase in the amount of beta-cells in IRS-1-deficient mice (IRS-1-/- mice) to compensate for insulin resistance. Thus, IRS-2 plays a crucial role in the regulation of beta-cell mass. On the other hand, insulin secretion by the same number of cells in response to glucose measured ex vivo was significantly increased in IRS-2-/- mice compared with wild-type mice but was decreased in IRS-1-/- mice. These results suggest that IRS-1 and IRS-2 may play different roles in the regulation of beta-cell mass and the function of individual beta-cells.
Collapse
Affiliation(s)
- N Kubota
- Department of Metabolic Disease, Graduate School of Medicine, University of Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Terauchi Y, Tobe K, Kadowaki T. [Genetic factors and life styles related to diabetes mellitus--with special reference to multiple factor inheritance]. Nihon Naika Gakkai Zasshi 2000; 89:1500-6. [PMID: 11062895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
|
40
|
Ogata N, Chikazu D, Kubota N, Terauchi Y, Tobe K, Azuma Y, Ohta T, Kadowaki T, Nakamura K, Kawaguchi H. Insulin receptor substrate-1 in osteoblast is indispensable for maintaining bone turnover. J Clin Invest 2000; 105:935-43. [PMID: 10749573 PMCID: PMC377487 DOI: 10.1172/jci9017] [Citation(s) in RCA: 218] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Insulin receptor substrates (IRS-1 and -2) are essential for intracellular signaling by insulin and IGF-I, anabolic regulators of bone metabolism. Mice lacking the IRS-1 gene IRS-1(-/-) showed severe osteopenia with low bone turnover. IRS-1 was expressed in osteoblasts, but not in osteoclasts, of wild-type (WT) mice. IRS-1(-/-) osteoblasts treated with insulin or IGF-I failed to induce tyrosine phosphorylation of cellular proteins, and they showed reduced proliferation and differentiation. Osteoclastogenesis in the coculture of hemopoietic cells and osteoblasts depended on IRS-1 expression in osteoblasts and could not be rescued by IRS-1 expression in hemopoietic cells in the presence of not only IGF-I but also 1,25(OH)(2)D(3). In addition, osteoclast differentiation factor (RANKL/ODF) was not induced by these factors in IRS-1(-/-) osteoblasts. We conclude that IRS-1 deficiency in osteoblasts impairs osteoblast proliferation, differentiation, and support of osteoclastogenesis, resulting in low-turnover osteopenia. Osteoblastic IRS-1 is essential for maintaining bone turnover, because it mediates signaling by IGF-I and insulin and, we propose, also by other factors, such as 1,25(OH)(2)D(3).
Collapse
Affiliation(s)
- N Ogata
- Department of Orthopaedic Surgery, and. Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Hara K, Tobe K, Uchigata Y, Nakazono M, Yasuda K, Terauchi Y, Iwamoto Y, Akanuma Y, Kimura S, Kadowaki T. Antibody-mediated insulin resistance treated by cessation of insulin administration. Intern Med 2000; 39:143-5. [PMID: 10732832 DOI: 10.2169/internalmedicine.39.143] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A 45-year-old Japanese man was referred to our hospital because of hyperglycemia despite the administration of as much as 120 U/day of human insulin. He had no history of injecting animal insulin. Free insulin was below 5 microU/ml, but a high titer of total insulin (about 3,000 microU/ml) was observed, suggesting the presence of antibodies against human insulin. Scatchard analysis showed an increased insulin binding capacity in the plasma characterized by a higher affinity for insulin. He was successfully treated by cessation of insulin administration. A Scatchard analysis series showed that a reduction in the insulin binding capacity of antibodies paralleled the improvement in glycemic control.
Collapse
Affiliation(s)
- K Hara
- The Institute for Diabetes Care and Research, Asahi Life Foundation, Tokyo
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Terauchi Y, Kubota N, Tamemoto H, Sakura H, Nagai R, Akanuma Y, Kimura S, Kadowaki T. Insulin effect during embryogenesis determines fetal growth: a possible molecular link between birth weight and susceptibility to type 2 diabetes. Diabetes 2000; 49:82-6. [PMID: 10615953 DOI: 10.2337/diabetes.49.1.82] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Low birth weight has been reported to be associated with impaired insulin secretion and insulin resistance. It has been proposed that this association results from fetal programming in response to the intrauterine environment (the thrifty phenotype hypothesis). To elucidate the relationship between birth weight and genetically determined defects in insulin secretion, we measured the birth weights of neonates derived from crosses of male pancreatic beta-cell type glucokinase knockout (Gck+/-) mice and female wild-type (WT) or Gck+/- mice. In 135 offspring, birth weights were lower in the presence of a fetal heterozygous mutation and higher in the presence of a maternal heterozygous mutation. Moreover, Gck-/- neonates had significantly smaller birth weights than WT or Gck+/- neonates (means +/- SE 1.49+/-0.03 [n = 30] vs. 1.63+/-0.03 [n = 30] or 1.63+/-0.02 [n = 50] g, respectively; P<0.01). Thus, Gck mutations in beta-cells may impair insulin response to glucose and alter intrauterine growth as well as glucose metabolism after birth. This study has confirmed the results of a previous report that human subjects carrying mutations in Gck had reduced birth weights and has provided direct evidence for a link between insulin and fetal growth. Moreover, birth weights were reduced in insulin receptor substrate-1 knockout mice despite normal insulin levels. Taken together, these results suggest that a genetically programmed insulin effect during embryogenesis determines fetal growth and provides a possible molecular link between birth weight and susceptibility to type 2 diabetes.
Collapse
Affiliation(s)
- Y Terauchi
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Kubota N, Terauchi Y, Miki H, Tamemoto H, Yamauchi T, Komeda K, Satoh S, Nakano R, Ishii C, Sugiyama T, Eto K, Tsubamoto Y, Okuno A, Murakami K, Sekihara H, Hasegawa G, Naito M, Toyoshima Y, Tanaka S, Shiota K, Kitamura T, Fujita T, Ezaki O, Aizawa S, Kadowaki T. PPAR gamma mediates high-fat diet-induced adipocyte hypertrophy and insulin resistance. Mol Cell 1999; 4:597-609. [PMID: 10549291 DOI: 10.1016/s1097-2765(00)80210-5] [Citation(s) in RCA: 1014] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Agonist-induced activation of peroxisome proliferator-activated receptor gamma (PPAR gamma) is known to cause adipocyte differentiation and insulin sensitivity. The biological role of PPAR gamma was investigated by gene targeting. Homozygous PPAR gamma-deficient embryos died at 10.5-11.5 dpc due to placental dysfunction. Quite unexpectedly, heterozygous PPAR gamma-deficient mice were protected from the development of insulin resistance due to adipocyte hypertrophy under a high-fat diet. These phenotypes were abrogated by PPAR gamma agonist treatment. Heterozygous PPAR gamma-deficient mice showed overexpression and hypersecretion of leptin despite the smaller size of adipocytes and decreased fat mass, which may explain these phenotypes at least in part. This study reveals a hitherto unpredicted role for PPAR gamma in high-fat diet-induced obesity due to adipocyte hypertrophy and insulin resistance, which requires both alleles of PPAR gamma.
Collapse
Affiliation(s)
- N Kubota
- Department of Metabolic Diseases, University of Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Eto K, Suga S, Wakui M, Tsubamoto Y, Terauchi Y, Taka J, Aizawa S, Noda M, Kimura S, Kasai H, Kadowaki T. NADH shuttle system regulates K(ATP) channel-dependent pathway and steps distal to cytosolic Ca(2+) concentration elevation in glucose-induced insulin secretion. J Biol Chem 1999; 274:25386-92. [PMID: 10464266 DOI: 10.1074/jbc.274.36.25386] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The NADH shuttle system is composed of the glycerol phosphate and malate-aspartate shuttles. We generated mice that lack mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH), a rate-limiting enzyme of the glycerol phosphate shuttle. Application of aminooxyacetate, an inhibitor of the malate-aspartate shuttle, to mGPDH-deficient islets demonstrated that the NADH shuttle system was essential for coupling glycolysis with activation of mitochondrial ATP generation to trigger glucose-induced insulin secretion. The present study revealed that blocking the NADH shuttle system severely suppressed closure of the ATP-sensitive potassium (K(ATP)) channel and depolarization of the plasma membrane in response to glucose in beta cells, although properties of the K(ATP) channel on the excised beta cell membrane were unaffected. In mGPDH-deficient islets treated with aminooxyacetate, Ca(2+) influx through the plasma membrane induced by a depolarizing concentration of KCl in the presence of the K(ATP) channel opener diazoxide restored insulin secretion. However, the level of the secretion was only approximately 40% of wild-type controls. Thus, glucose metabolism through the NADH shuttle system leading to efficient ATP generation is pivotal to activation of both the K(ATP) channel-dependent pathway and steps distal to an elevation of cytosolic Ca(2+) concentration in glucose-induced insulin secretion.
Collapse
Affiliation(s)
- K Eto
- Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Eto K, Tsubamoto Y, Terauchi Y, Sugiyama T, Kishimoto T, Takahashi N, Yamauchi N, Kubota N, Murayama S, Aizawa T, Akanuma Y, Aizawa S, Kasai H, Yazaki Y, Kadowaki T. Role of NADH shuttle system in glucose-induced activation of mitochondrial metabolism and insulin secretion. Science 1999; 283:981-5. [PMID: 9974390 DOI: 10.1126/science.283.5404.981] [Citation(s) in RCA: 379] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Glucose metabolism in glycolysis and in mitochondria is pivotal to glucose-induced insulin secretion from pancreatic beta cells. One or more factors derived from glycolysis other than pyruvate appear to be required for the generation of mitochondrial signals that lead to insulin secretion. The electrons of the glycolysis-derived reduced form of nicotinamide adenine dinucleotide (NADH) are transferred to mitochondria through the NADH shuttle system. By abolishing the NADH shuttle function, glucose-induced increases in NADH autofluorescence, mitochondrial membrane potential, and adenosine triphosphate content were reduced and glucose-induced insulin secretion was abrogated. The NADH shuttle evidently couples glycolysis with activation of mitochondrial energy metabolism to trigger insulin secretion.
Collapse
Affiliation(s)
- K Eto
- Department of Internal Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan. Tokyo
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Terauchi Y, Tsuji Y, Satoh S, Minoura H, Murakami K, Okuno A, Inukai K, Asano T, Kaburagi Y, Ueki K, Nakajima H, Hanafusa T, Matsuzawa Y, Sekihara H, Yin Y, Barrett JC, Oda H, Ishikawa T, Akanuma Y, Komuro I, Suzuki M, Yamamura K, Kodama T, Suzuki H, Yamamura K, Kodama T, Suzuki H, Koyasu S, Aizawa S, Tobe K, Fukui Y, Yazaki Y, Kadowaki T. Increased insulin sensitivity and hypoglycaemia in mice lacking the p85 alpha subunit of phosphoinositide 3-kinase. Nat Genet 1999; 21:230-5. [PMID: 9988280 DOI: 10.1038/6023] [Citation(s) in RCA: 312] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The hallmark of type 2 diabetes, the most common metabolic disorder, is a defect in insulin-stimulated glucose transport in peripheral tissues. Although a role for phosphoinositide-3-kinase (PI3K) activity in insulin-stimulated glucose transport and glucose transporter isoform 4 (Glut4) translocation has been suggested in vitro, its role in vivo and the molecular link between activation of PI3K and translocation has not yet been elucidated. To determine the role of PI3K in glucose homeostasis, we generated mice with a targeted disruption of the gene encoding the p85alpha regulatory subunit of PI3K (Pik3r1; refs 3-5). Pik3r1-/- mice showed increased insulin sensitivity and hypoglycaemia due to increased glucose transport in skeletal muscle and adipocytes. Insulin-stimulated PI3K activity associated with insulin receptor substrates (IRSs) was mediated via full-length p85 alpha in wild-type mice, but via the p50 alpha alternative splicing isoform of the same gene in Pik3r1-/- mice. This isoform switch was associated with an increase in insulin-induced generation of phosphatidylinositol(3,4,5)triphosphate (PtdIns(3,4,5)P3) in Pik3r1-/- adipocytes and facilitation of Glut4 translocation from the low-density microsome (LDM) fraction to the plasma membrane (PM). This mechanism seems to be responsible for the phenotype of Pik3r1-/- mice, namely increased glucose transport and hypoglycaemia. Our work provides the first direct evidence that PI3K and its regulatory subunit have a role in glucose homeostasis in vivo.
Collapse
Affiliation(s)
- Y Terauchi
- Department of Internal Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Suzuki H, Terauchi Y, Fujiwara M, Aizawa S, Yazaki Y, Kadowaki T, Koyasu S. Xid-like immunodeficiency in mice with disruption of the p85alpha subunit of phosphoinositide 3-kinase. Science 1999; 283:390-2. [PMID: 9888854 DOI: 10.1126/science.283.5400.390] [Citation(s) in RCA: 361] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mice with a targeted gene disruption of p85alpha, a regulatory subunit of phosphoinositide 3-kinase, had impaired B cell development at the pro-B cell stage, reduced numbers of mature B cells and peritoneal CD5+ Ly-1 B cells, reduced B cell proliferative responses, and no T cell-independent antibody production. These phenotypes are nearly identical to those of Btk-/- or xid (X-linked immunodeficiency) mice. These results provide evidence that p85alpha is functionally linked to the Btk pathway in antigen receptor-mediated signal transduction and is pivotal in B cell development and functions.
Collapse
Affiliation(s)
- H Suzuki
- Department of Immunology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | | | | | | | | | | | | |
Collapse
|
48
|
Hayakawa T, Noda M, Yasuda K, Yorifuji H, Taniguchi S, Miwa I, Sakura H, Terauchi Y, Hayashi J, Sharp GW, Kanazawa Y, Akanuma Y, Yazaki Y, Kadowaki T. Ethidium bromide-induced inhibition of mitochondrial gene transcription suppresses glucose-stimulated insulin release in the mouse pancreatic beta-cell line betaHC9. J Biol Chem 1998; 273:20300-7. [PMID: 9685380 DOI: 10.1074/jbc.273.32.20300] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, a mitochondrial mutation was found to be associated with maternally inherited diabetes mellitus (Kadowaki, T., Kadowaki, H., Mori, Y., Tobe, K., Sakuta, R., Suzuki, Y., Tanabe, Y, Sakura, H., Awata, T., Goto, Y., Hayakawa, T., Matsuoka, K., Kawamori, R., Kamada, T., Horai, S., Nonaka, I., Hagura, R., Akanuma, Y., and Yazaki, Y. (1994) N. Engl. J. Med. 330, 962-968). In order to elucidate its etiology, we have investigated the involvement of mitochondrial function in insulin secretion. Culture of the pancreatic beta-cell line, betaHC9, with low dose ethidium bromide (EB) (0.4 microg/ml) for 2-6 days resulted in a substantial decrease in the transcription level of mitochondrial DNA (to 10-20% of the control cells) without changing its copy number, whereas the transcription of nuclear genes was grossly unaffected. Electron microscopic analysis revealed that treatment by EB caused morphological changes only in mitochondria and not in other organelles such as nuclei, endoplasmic reticula, Golgi bodies, or secretory granules. When the cells were treated with EB for 6 days, glucose (20 mM) could no longer stimulate insulin secretion, while glibenclamide (1 microM) still did. When EB was removed after 3- or 6-day treatment, mitochondrial gene transcription recovered within 2 days, and the profiles of insulin secretion returned to normal within 7 days. Studies with fura-2 indicated that in EB-treated cells, glucose (20 mM) failed to increase intracellular Ca2+, while the effect of glibenclamide (1 microM) was maintained. Our system provides a unique way to investigate the relationship between mitochondrial function and insulin secretion.
Collapse
Affiliation(s)
- T Hayakawa
- Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Sakura H, Ashcroft SJ, Terauchi Y, Kadowaki T, Ashcroft FM. Glucose modulation of ATP-sensitive K-currents in wild-type, homozygous and heterozygous glucokinase knock-out mice. Diabetologia 1998; 41:654-9. [PMID: 9662046 DOI: 10.1007/s001250050964] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One type of maturity-onset diabetes of the young (MODY2) is caused by mutations in the glucokinase gene, a key glycolytic enzyme in the beta cell and liver. Glucose fails to stimulate insulin secretion in mice in which the glucokinase gene has been selectively knocked out in the beta cell. We tested the hypothesis that this effect results from defective metabolic regulation of beta cell ATP-sensitive potassium (K(ATP)) channels. Glucose had little effect on K(ATP) currents in homozygous (-/-) mice but inhibited K(ATP) currents in wild-type (+/+) and heterozygous (+/-) mice with EC50 of 3.2 mM and 5.5 mM, respectively, in newborn animals, and of 4.7 mM and 9.9 mM, respectively, in 1.5-year-old mice. Glucose (20 mmol/l) did not affect the resting membrane potential of -/- beta cells but depolarised wild-type and + /- beta cells and induced electrical activity. In contrast, 20 mmol/l ketoisocaproic acid or 0.5 mmol/ l tolbutamide depolarised all three types of beta-cell. These results support the idea that defective glycolytic metabolism, produced by a loss (-/- mice) or reduction (+/- mice) of glucokinase activity, leads to defective K(ATP) channel regulation and thereby to the selective loss, or reduction, of glucose-induced insulin secretion.
Collapse
Affiliation(s)
- H Sakura
- University Laboratory of Physiology, Oxford, UK
| | | | | | | | | |
Collapse
|
50
|
Hashizume T, Mise M, Terauchi Y, O L, Fujii T, Miyazaki H, Inaba T. N-Dealkylation and hydroxylation of ebastine by human liver cytochrome P450. Drug Metab Dispos 1998; 26:566-71. [PMID: 9616193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Ebastine [4'-tert-butyl-4-[4-(diphenylmethoxy)piperidino]butyro phe- none] is a new-generation, nonsedative, H1 antihistamine. The present study was performed to characterize the cytochrome P450 (CYP) isoforms responsible for ebastine N-dealkylation and hydroxylation. Human liver microsomes metabolized ebastine to two major metabolites, i.e. a desbutyrophenone metabolite (des-BP) and hydroxyebastine (M-OH), and the ratio of Vmax values was 3:1. N-Dealkylation yielded des-BP, whereas M-OH, an hydroxylation product, could be further oxidized to the pharmacologically active carebastine. In a panel of 14 human liver microsomal preparations, the rate of dealkylation showed a highly significant correlation with CYP3A-mediated testosterone 6beta-hydroxylation but not with reactions of seven other CYP isoforms. However, there was no correlation between the two pathways for ebastine (dealkylation and hydroxylation). Differential chemical inhibition in liver microsomes, in which dealkylation was more sensitive than hydroxylation, was demonstrated with ketoconazole, troleandomycin, cyclosporin A, and midazolam. Anti-CYP3A antibodies markedly reduced the dealkylation rate (>95%) in liver microsomes but exhibited insignificant effects on hydroxylation (<5%). Among 12 cDNA-expressed human CYP isoforms, which account for up to 70% of the total CYP enzyme content in human liver, CYP3A4 alone metabolized ebastine; the ratio of des-BP to M-OH formation was 12:1. This ratio for metabolism by the pure enzyme was much larger than the ratio (3:1) observed for the microsomal reaction mixture. This change in ratio, which is attributed to a decrease in M-OH formation, indicates that, although ebastine is metabolized to two major metabolites, N-dealkylation to des-BP is mediated by CYP3A, whereas hydroxylation to M-OH appears to be mediated mainly by unidentified enzymes other than CYP3A.
Collapse
Affiliation(s)
- T Hashizume
- Developmental Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki, 33-94, Suita, Osaka, 564, Japan
| | | | | | | | | | | | | |
Collapse
|