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Hasebe M, Aizawa-Abe M, Shibue K, Hamasaki A. Successful Treatment of Postprandial Hyperinsulinemic Hypoglycemia After Billroth-II Gastrojejunostomy Using Octreotide. JCEM Case Rep 2023; 1:luad150. [PMID: 38045869 PMCID: PMC10690849 DOI: 10.1210/jcemcr/luad150] [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] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Indexed: 12/05/2023]
Abstract
Postprandial hyperinsulinemic hypoglycemia, although rare, is a well-documented complication that can manifest after upper gastrointestinal surgery. Despite its potential for severe morbidity, the underlying pathogenesis and optimal treatment strategies for this condition remain insufficiently understood. This report presents a compelling case of postprandial hypoglycemia following Billroth-II gastrojejunostomy, characterized by a marked increase in postprandial insulin levels, accompanied by the exaggerated response of incretin hormones. The incretin effect in this patient was found to be exceptionally high, measuring at approximately 90%. While nutritional interventions proved ineffective in alleviating the patient's symptoms, the administration of octreotide significantly attenuated the exaggerated postprandial insulin and incretin response, substantially ameliorating both the symptoms and postprandial hypoglycemia. Monthly subcutaneous injections of long-acting repeatable octreotide were initiated, resulting in the complete resolution of symptomatic postprandial hypoglycemia. Although the patient developed acalculous cholecystitis and gallstone cholangitis 2 years after commencing octreotide therapy, she has remained free from symptomatic postprandial hypoglycemia for more than 4 years. Our case underscores the efficacy of somatostatin analogs in the management of postprandial hyperinsulinemia after gastrointestinal surgery, shedding light on the potential involvement of incretin hormones in the pathophysiology of this condition.
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Affiliation(s)
- Masashi Hasebe
- Department of Diabetes and Endocrinology, Medical Research Institute Kitano Hospital, PIIF Tazuke-Kofukai, Kita-ku, Osaka 530-8480, Japan
| | - Megumi Aizawa-Abe
- Department of Diabetes and Endocrinology, Medical Research Institute Kitano Hospital, PIIF Tazuke-Kofukai, Kita-ku, Osaka 530-8480, Japan
- Division of Diabetes and Endocrinology, Osaka Saiseikai-Noe Hospital, Osaka 536-0001, Japan
| | - Kimitaka Shibue
- Department of Diabetes and Endocrinology, Medical Research Institute Kitano Hospital, PIIF Tazuke-Kofukai, Kita-ku, Osaka 530-8480, Japan
| | - Akihiro Hamasaki
- Department of Diabetes and Endocrinology, Medical Research Institute Kitano Hospital, PIIF Tazuke-Kofukai, Kita-ku, Osaka 530-8480, Japan
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Ebihara C, Aizawa-Abe M, Zhao M, Gumbilai V, Ebihara K. Different sites of actions make different responses to thiazolidinediones between mouse and rat models of fatty liver. Sci Rep 2022; 12:449. [PMID: 35013417 PMCID: PMC8748829 DOI: 10.1038/s41598-021-04036-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 11/30/2021] [Indexed: 02/06/2023] Open
Abstract
Therapeutic approach for NAFLD is limited and there are no approved drugs. Pioglitazone (PGZ), a thiazolidinedione (TZD) that acts via peroxisome proliferator activated receptor gamma (PPARγ) is the only agent that has shown consistent benefit and efficacy in clinical trials. However, the mechanism of its therapeutic effect on NAFLD remains unclear. The poor understanding may be due to problems with mouse, a species most used for animal experiments. TZDs exacerbate fatty liver in mouse models while they improve it in rat models like in human patients. Therefore, we compared the effects of TZDs including PGZ and rosiglitazone (RGZ) in ob/ob mice and Lepmkyo/Lepmkyo rats, models of leptin-deficient obesity, and A-ZIP/F-1 mice and seipin knockout (SKO) rats, models of generalized lipodystrophy. Pparg mRNA expression was markedly upregulated in fatty livers of mouse models while it was unchanged in rat models. TZDs exacerbated fatty liver in ob/ob and A-ZIP/F-1 mice, improved it in Lepmkyo/Lepmkyo rats and showed no effect in SKO rats. Gene expression analyses of Pparg and its target gene, Fsp27 revealed that PPARγ in the adipose tissue is the exclusive therapeutic target of TZDs in rats but PPARγ in the liver in addition to the adipose tissue is also a major site of actions for TZDs in mice. Although the response to TZDs in mice is the complete opposite of that in human patients, no report has pointed out the problem with TZD studies using mouse models so far. The present study might provide useful suggestions in research on TZDs.
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Affiliation(s)
- Chihiro Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Megumi Aizawa-Abe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan
| | - Mingming Zhao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Valentino Gumbilai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ken Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan.
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan.
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Yoshiji S, Horikawa Y, Kubota S, Enya M, Iwasaki Y, Keidai Y, Aizawa-Abe M, Iwasaki K, Honjo S, Hosomichi K, Yabe D, Hamasaki A. First Japanese Family With PDX1-MODY (MODY4): A Novel PDX1 Frameshift Mutation, Clinical Characteristics, and Implications. J Endocr Soc 2022; 6:bvab159. [PMID: 34988346 PMCID: PMC8714237 DOI: 10.1210/jendso/bvab159] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Indexed: 11/19/2022] Open
Abstract
CONTEXT The PDX1 gene encodes pancreatic and duodenal homeobox, a critical transcription factor for pancreatic β-cell differentiation and maintenance of mature β-cells. Heterozygous loss-of-function mutations cause PDX1-MODY (MODY4). CASE DESCRIPTION Our patient is an 18-year-old lean man who developed diabetes at 16 years of age. Given his early-onset age and leanness, we performed genetic testing. Targeted next-generation sequencing and subsequent Sanger sequencing detected a novel heterozygous frameshift mutation (NM_00209.4:c.218delT. NP_000200.1: p.Leu73Profs*50) in the PDX1 transactivation domain that resulted in loss-of-function and was validated by an in vitro functional study. The proband and his 56-year-old father, who had the same mutation, both showed markedly reduced insulin and gastric inhibitory polypeptide (GIP) secretion compared with the dizygotic twin sister, who was negative for the mutation and had normal glucose tolerance. The proband responded well to sitagliptin, suggesting its utility as a treatment option. Notably, the proband and his father showed intriguing phenotypic differences: the proband had been lean for his entire life but developed early-onset diabetes requiring an antihyperglycemic agent. In contrast, his father was overweight, developed diabetes much later in life, and did not require medication, suggesting the oligogenic nature of PDX1-MODY. A review of all reported cases of PDX1-MODY also showed heterogeneous phenotypes regarding onset age, obesity, and treatment, even in the presence of the same mutation. CONCLUSIONS We identified the first Japanese family with PDX1-MODY. The similarities and differences found among the cases highlight the wide phenotypic spectrum of PDX1-MODY.
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Affiliation(s)
- Satoshi Yoshiji
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- Department of Human Genetics, McGill University, Montréal, Québec H3A 0C7, Canada
- Kyoto-McGill International Collaborative Program in Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yukio Horikawa
- Department of Diabetes, Endocrinology and Metabolism, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan
- Clinical Genetics Center, Gifu University Hospital, Gifu 501-1194, Japan
| | - Sodai Kubota
- Department of Diabetes, Endocrinology and Metabolism, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan
| | - Mayumi Enya
- Department of Diabetes, Endocrinology and Metabolism, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan
| | - Yorihiro Iwasaki
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Yamato Keidai
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Megumi Aizawa-Abe
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
| | - Kanako Iwasaki
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
| | - Sachiko Honjo
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
| | - Kazuyoshi Hosomichi
- Department of Bioinformatics and Genomics, Kanazawa University, Kanazawa 920-8640, Japan
| | - Daisuke Yabe
- Department of Diabetes, Endocrinology and Metabolism, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan
| | - Akihiro Hamasaki
- Department of Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
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Tanaka T, Kusakabe T, Ebihara K, Aizawa-Abe M, Aotani D, Yorifuji T, Satoh M, Ogawa Y, Nakao K. Practice guideline for lipodystrophy syndromes-clinically important diseases of the Japan Endocrine Society (JES). Endocr J 2021; 68:1027-1042. [PMID: 34373417 DOI: 10.1507/endocrj.ej21-0110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Tomohiro Tanaka
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
- Department of Gastroenterology and Metabolism, Graduate School of Medical Sciences and Medical School, Nagoya City University, Nagoya 467-8601, Japan
| | - Toru Kusakabe
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
- National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Ken Ebihara
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Jichi Medical University, Tochigi 329-0431, Japan
| | - Megumi Aizawa-Abe
- Tazuke Kofukai, Medical Research Institute, Kitano Hospital, Osaka 530-8480, Japan
| | - Daisuke Aotani
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
- Department of Gastroenterology and Metabolism, Graduate School of Medical Sciences and Medical School, Nagoya City University, Nagoya 467-8601, Japan
| | - Tohru Yorifuji
- Pediatric Endocrinology and Metabolism, Osaka City General Hospital, Osaka 534-0021, Japan
| | - Mari Satoh
- Pediatrics Center, Toho University Omori Medical Center, Tokyo 143-8540, Japan
| | - Yoshihiro Ogawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 821-8582, Japan
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Kazuwa Nakao
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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5
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Seno Y, Iwasaki Y, Aizawa-Abe M, Iwasaki K, Yoshiji S, Honjo S, Hamasaki A. Facilitating screening of Klinefelter syndrome among patients with diabetes. J Diabetes Investig 2019; 11:506-507. [PMID: 31389187 PMCID: PMC7078131 DOI: 10.1111/jdi.13113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/25/2019] [Accepted: 07/07/2019] [Indexed: 12/03/2022] Open
Affiliation(s)
- Yohei Seno
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Yorihiro Iwasaki
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Megumi Aizawa-Abe
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Kanako Iwasaki
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Satoshi Yoshiji
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Sachiko Honjo
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Akihiro Hamasaki
- Center for Diabetes and Endocrinology, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
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Keidai Y, Iwasaki Y, Honjo S, Aizawa-Abe M, Iwasaki K, Hamasaki A. "Switched" metabolic acidosis in mitochondrial diabetes mellitus. J Diabetes Investig 2019; 10:1116-1117. [PMID: 30659759 PMCID: PMC6626961 DOI: 10.1111/jdi.12992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/26/2018] [Accepted: 12/13/2018] [Indexed: 11/27/2022] Open
Abstract
A patient with mitochondrial diabetes mellitus developed diabetic ketoacidosis. During insulin treatment, although diabetic ketoacidosis improved, lactic acidosis unexpectedly worsened. This clinical course, named “switched metabolic acidosis,” could reflect the unique pathophysiology of the mitochondrial disorder.![]()
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Affiliation(s)
- Yamato Keidai
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Yorihiro Iwasaki
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Sachiko Honjo
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Megumi Aizawa-Abe
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Kanako Iwasaki
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Akihiro Hamasaki
- Center for Diabetes and Endocrinology, The Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
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7
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Goto T, Hirata M, Aoki Y, Iwase M, Takahashi H, Kim M, Li Y, Jheng HF, Nomura W, Takahashi N, Kim CS, Yu R, Seno S, Matsuda H, Aizawa-Abe M, Ebihara K, Itoh N, Kawada T. The hepatokine FGF21 is crucial for peroxisome proliferator-activated receptor-α agonist-induced amelioration of metabolic disorders in obese mice. J Biol Chem 2017; 292:9175-9190. [PMID: 28404815 DOI: 10.1074/jbc.m116.767590] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [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: 11/13/2016] [Revised: 04/12/2017] [Indexed: 01/05/2023] Open
Abstract
Obesity causes excess fat accumulation in white adipose tissues (WAT) and also in other insulin-responsive organs such as the skeletal muscle, increasing the risk for insulin resistance, which can lead to obesity-related metabolic disorders. Peroxisome proliferator-activated receptor-α (PPARα) is a master regulator of fatty acid oxidation whose activator is known to improve hyperlipidemia. However, the molecular mechanisms underlying PPARα activator-mediated reduction in adiposity and improvement of metabolic disorders are largely unknown. In this study we investigated the effects of PPARα agonist (fenofibrate) on glucose metabolism dysfunction in obese mice. Fenofibrate treatment reduced adiposity and attenuated obesity-induced dysfunctions of glucose metabolism in obese mice fed a high-fat diet. However, fenofibrate treatment did not improve glucose metabolism in lipodystrophic A-Zip/F1 mice, suggesting that adipose tissue is important for the fenofibrate-mediated amelioration of glucose metabolism, although skeletal muscle actions could not be completely excluded. Moreover, we investigated the role of the hepatokine fibroblast growth factor 21 (FGF21), which regulates energy metabolism in adipose tissue. In WAT of WT mice, but not of FGF21-deficient mice, fenofibrate enhanced the expression of genes related to brown adipocyte functions, such as Ucp1, Pgc1a, and Cpt1b Fenofibrate increased energy expenditure and attenuated obesity, whole body insulin resistance, and adipocyte dysfunctions in WAT in high-fat-diet-fed WT mice but not in FGF21-deficient mice. These findings indicate that FGF21 is crucial for the fenofibrate-mediated improvement of whole body glucose metabolism in obese mice via the amelioration of WAT dysfunctions.
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Affiliation(s)
- Tsuyoshi Goto
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan, .,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8501 Japan
| | - Mariko Hirata
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Yumeko Aoki
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Mari Iwase
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Haruya Takahashi
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Minji Kim
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Yongjia Li
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Huei-Fen Jheng
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan
| | - Wataru Nomura
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan.,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8501 Japan
| | - Nobuyuki Takahashi
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan.,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8501 Japan
| | - Chu-Sook Kim
- Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749, South Korea
| | - Rina Yu
- Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749, South Korea
| | - Shigeto Seno
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita 565-0871, Japan
| | - Hideo Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita 565-0871, Japan
| | - Megumi Aizawa-Abe
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto 606-8507, Japan, and
| | - Ken Ebihara
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto 606-8507, Japan, and
| | - Nobuyuki Itoh
- Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto 606-8501, Japan
| | - Teruo Kawada
- From the Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011, Japan.,Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto 606-8501 Japan
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Gumbilai V, Ebihara K, Aizawa-Abe M, Ebihara C, Zhao M, Yamamoto Y, Mashimo T, Hosoda K, Serikawa T, Nakao K. Fat Mass Reduction With Adipocyte Hypertrophy and Insulin Resistance in Heterozygous PPARγ Mutant Rats. Diabetes 2016; 65:2954-65. [PMID: 27381370 DOI: 10.2337/db15-1422] [Citation(s) in RCA: 17] [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] [Received: 10/13/2015] [Accepted: 06/30/2016] [Indexed: 11/13/2022]
Abstract
Agonist-induced activation of peroxisome proliferator-activated receptor-γ (PPARγ) stimulates adipocyte differentiation and insulin sensitivity. Patients with heterozygous PPARγ dominant-negative mutation develop partial lipodystrophy and insulin resistance. Inconsistent with this evidence in humans, it was reported that heterozygous PPARγ knockout mice have increased insulin sensitivity and that mice with heterozygous PPARγ dominant-negative mutation have normal insulin sensitivity and improved glucose tolerance. In the context of the interspecies intranslatability of PPARγ-related findings, we generated a PPARγ mutant rat with a loss-of-function mutation (Pparg(mkyo)) without dominant-negative activity by using the ENU (N-ethyl-N-nitrosourea) mutagenesis method. Heterozygous Pparg(mkyo/+) rats showed reduced fat mass with adipocyte hypertrophy and insulin resistance, which were highly predictable from known actions of PPARγ agonists and phenotypes of patients with the PPARγ mutation. This report is the first in our knowledge to clearly demonstrate that both alleles of PPARγ are required for normal adipocyte development and insulin sensitivity in vivo. Furthermore, the study indicates that PPARγ regulates mainly adipocyte number rather than adipocyte size in vivo. The choice of appropriate species as experimental models is critical, especially for the study of PPARγ.
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Affiliation(s)
- Valentino Gumbilai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ken Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan Division of Endocrinology and Metabolism, Jichi Medical University, Tochigi, Japan
| | - Megumi Aizawa-Abe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan
| | - Chihiro Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan Division of Endocrinology and Metabolism, Jichi Medical University, Tochigi, Japan
| | - Mingming Zhao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuji Yamamoto
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomoji Mashimo
- Institute of Laboratory Animals, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan Department of Health and Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tadao Serikawa
- Institute of Laboratory Animals, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kazuwa Nakao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
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9
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Ebihara C, Ebihara K, Aizawa-Abe M, Mashimo T, Tomita T, Zhao M, Gumbilai V, Kusakabe T, Yamamoto Y, Aotani D, Yamamoto-Kataoka S, Sakai T, Hosoda K, Serikawa T, Nakao K. Seipin is necessary for normal brain development and spermatogenesis in addition to adipogenesis. Hum Mol Genet 2015; 24:4238-49. [PMID: 25934999 DOI: 10.1093/hmg/ddv156] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/27/2015] [Indexed: 12/31/2022] Open
Abstract
Seipin, encoded by BSCL2 gene, is a protein whose physiological functions remain unclear. Mutations of BSCL2 cause the most-severe form of congenital generalized lipodystrophy (CGL). BSCL2 mRNA is highly expressed in the brain and testis in addition to the adipose tissue in human, suggesting physiological roles of seipin in non-adipose tissues. Since we found BSCL2 mRNA expression pattern among organs in rat is similar to human while it is not highly expressed in mouse brain, we generated a Bscl2/seipin knockout (SKO) rat using the method with ENU (N-ethyl-N-nitrosourea) mutagenesis. SKO rats showed total lack of white adipose tissues including mechanical fat such as bone marrow and retro-orbital fats, while physiologically functional brown adipose tissue was preserved. Besides the lipodystrophic phenotypes, SKO rats showed impairment of spatial working memory with brain weight reduction and infertility with azoospermia. We confirmed reduction of brain volume and number of sperm in human patients with BSCL2 mutation. This is the first report demonstrating that seipin is necessary for normal brain development and spermatogenesis in addition to white adipose tissue development.
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Affiliation(s)
| | - Ken Ebihara
- Department of Medicine and Clinical Science, Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan
| | - Megumi Aizawa-Abe
- Department of Medicine and Clinical Science, Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan
| | | | | | | | | | - Toru Kusakabe
- Department of Medicine and Clinical Science, Medical Innovation Center
| | | | - Daisuke Aotani
- Department of Medicine and Clinical Science, Medical Innovation Center
| | | | | | - Kiminori Hosoda
- Department of Medicine and Clinical Science, Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan Department of Health and Science, Kyoto University Graduate School of Medicine, Kyoto 6068507, Japan and
| | | | - Kazuwa Nakao
- Department of Medicine and Clinical Science, Medical Innovation Center
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10
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Yamamoto-Kataoka S, Ebihara K, Aizawa-Abe M, Nishio M, Kusakabe T, Yamamoto Y, Aotani D, Sakai T, Zhao M, Ebihara C, Gumbilai VMJ, Hosoda K, Suzuki A, Nakao K. Leptin improves fatty liver independently of insulin sensitization and appetite suppression in hepatocyte-specific Pten-deficient mice with insulin hypersensitivity. Horm Metab Res 2015; 47:168-75. [PMID: 25415231 DOI: 10.1055/s-0034-1395531] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 10/24/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is recognized as the hepatic component of the metabolic syndrome. Although NAFLD is a major cause of cirrhosis and cancer of the liver of unknown cause, no established pharmacological treatment for NAFLD has been established yet. It has been reported that leptin treatment improved fatty liver dramatically as well as insulin resistance and hyperphagia in patients with lipodystrophy. However, it is unclear whether leptin improves fatty liver independently of these metabolic improvements. We investigated the liver effect of leptin independently of insulin sensitization and appetite suppression using hepatocyte-specific Pten-deficient (AlbCrePtenff) mouse, a model of severe fatty liver with insulin hypersensitivity. Male AlbCrePtenff mice were infused subcutaneously with leptin (20 ng/g/h) for 2 weeks using osmotic minipumps. Leptin infusion effectively reduced liver weight, liver triglyceride content, and glutamate pyruvate transaminase (GPT) concentrations as well as food intake and body weight without the change of plasma insulin concentration in AlbCrePtenff mice. Pair-feeding also reduced body weight but not liver triglyceride content. Pair feeding reduced α1 and α2 AMP-activated protein kinase (AMPK) activities and PGC1α gene expression in the liver, while leptin infusion unchanged them. The present study clearly demonstrated that leptin improve fatty liver independently of insulin sensitization and suppression of food intake. It was suggested that leptin improves fatty liver by stimulation of β-oxidation in the liver. The present study might provide a further understanding on the mechanism of metabolic effect of leptin.
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Affiliation(s)
- S Yamamoto-Kataoka
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - K Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - M Aizawa-Abe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - M Nishio
- Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - T Kusakabe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Y Yamamoto
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - D Aotani
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - T Sakai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - M Zhao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - C Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - V M J Gumbilai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - K Hosoda
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - A Suzuki
- Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - K Nakao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan
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11
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Sakai T, Kusakabe T, Ebihara K, Aotani D, Yamamoto-Kataoka S, Zhao M, Gumbilai VMJ, Ebihara C, Aizawa-Abe M, Yamamoto Y, Noguchi M, Fujikura J, Hosoda K, Inagaki N, Nakao K. Leptin restores the insulinotropic effect of exenatide in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet. Am J Physiol Endocrinol Metab 2014; 307:E712-9. [PMID: 25159327 DOI: 10.1152/ajpendo.00272.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 01/12/2023]
Abstract
Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair β-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired β-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 μg·kg⁻¹·day⁻¹) and/or exenatide (20 μg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.
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Affiliation(s)
- Takeru Sakai
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan; Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toru Kusakabe
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan;
| | - Ken Ebihara
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan; and
| | - Daisuke Aotani
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sachiko Yamamoto-Kataoka
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mingming Zhao
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | | | - Chihiro Ebihara
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Megumi Aizawa-Abe
- Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, Kyoto, Japan; and
| | - Yuji Yamamoto
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Michio Noguchi
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Junji Fujikura
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Human Health Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kazuwa Nakao
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
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12
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Aizawa-Abe M, Ebihara K, Ebihara C, Mashimo T, Takizawa A, Tomita T, Kusakabe T, Yamamoto Y, Aotani D, Yamamoto-Kataoka S, Sakai T, Hosoda K, Serikawa T, Nakao K. Generation of leptin-deficient Lepmkyo/Lepmkyo rats and identification of leptin-responsive genes in the liver. Physiol Genomics 2013; 45:786-93. [DOI: 10.1152/physiolgenomics.00040.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leptin is one of the key molecules in maintaining energy homeostasis. Although genetically leptin-deficient Lep ob /Lep ob mice have greatly contributed to elucidating leptin physiology, the use of more than one species can improve the accuracy of analysis results. Using the N-ethyl- N-nitrosourea mutagenesis method, we generated a leptin-deficient Lep mkyo /Lep mkyo rat that had a nonsense mutation (Q92X) in leptin gene. Lep mkyo /Lep mkyo rats showed obese phenotypes including severe fatty liver, which were comparable to Lep ob /Lep ob mice. To identify genes that respond to leptin in the liver, we performed microarray analysis with Lep mkyo /Lep mkyo rats and Lep ob /Lep ob mice. We sorted out genes whose expression levels in the liver of Lep mkyo /Lep mkyo rats were changed from wild-type (WT) rats and were reversed toward WT rats by leptin administration. In this analysis, livers were sampled for 6 h, a relatively short time after leptin administration to avoid the secondary effect of metabolic changes such as improvement of fatty liver. We did the same procedure in Lep ob /Lep ob mice and selected genes whose expression patterns were common in rat and mouse. We verified their gene expressions by real-time quantitative PCR. Finally, we identified eight genes that primarily respond to leptin in the liver commonly in rat and mouse. These genes might be important for the effect of leptin in the liver.
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Affiliation(s)
- Megumi Aizawa-Abe
- Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ken Ebihara
- Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Chihiro Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomoji Mashimo
- Institute of Laboratory Animals, Kyoto University Graduate School of Medicine, Kyoto, Japan; and
| | - Akiko Takizawa
- Institute of Laboratory Animals, Kyoto University Graduate School of Medicine, Kyoto, Japan; and
| | - Tsutomu Tomita
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toru Kusakabe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuji Yamamoto
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Aotani
- Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sachiko Yamamoto-Kataoka
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takeru Sakai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, Kyoto, Japan
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Health and Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tadao Serikawa
- Institute of Laboratory Animals, Kyoto University Graduate School of Medicine, Kyoto, Japan; and
| | - Kazuwa Nakao
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
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13
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Aotani D, Ebihara K, Sawamoto N, Kusakabe T, Aizawa-Abe M, Kataoka S, Sakai T, Iogawa H, Ebihara C, Fujikura J, Hosoda K, Fukuyama H, Nakao K. Functional magnetic resonance imaging analysis of food-related brain activity in patients with lipodystrophy undergoing leptin replacement therapy. J Clin Endocrinol Metab 2012; 97:3663-71. [PMID: 22872692 PMCID: PMC3462942 DOI: 10.1210/jc.2012-1872] [Citation(s) in RCA: 39] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CONTEXT Lipodystrophy is a disease characterized by a paucity of adipose tissue and low circulating concentrations of adipocyte-derived leptin. Leptin-replacement therapy improves eating and metabolic disorders in patients with lipodystrophy. OBJECTIVE The aim of the study was to clarify the pathogenic mechanism of eating disorders in lipodystrophic patients and the action mechanism of leptin on appetite regulation. SUBJECTS AND INTERVENTIONS We investigated food-related neural activity using functional magnetic resonance imaging in lipodystrophic patients with or without leptin replacement therapy and in healthy controls. We also measured the subjective feelings of appetite. RESULTS Although there was little difference in the enhancement of neural activity by food stimuli between patients and controls under fasting, postprandial suppression of neural activity was insufficient in many regions of interest including amygdala, insula, nucleus accumbens, caudate, putamen, and globus pallidus in patients when compared with controls. Leptin treatment effectively suppressed postprandial neural activity in many of these regions of interest, whereas it showed little effect under fasting in patients. Consistent with these results, postprandial formation of satiety feeling was insufficient in patients when compared with controls, which was effectively reinforced by leptin treatment. CONCLUSIONS This study demonstrated the insufficiency of postprandial suppression of food-related neural activity and formation of satiety feeling in lipodystrophic patients, which was effectively restored by leptin. The findings in this study emphasize the important pathological role of leptin in eating disorders in lipodystrophy and provide a clue to understanding the action mechanism of leptin in human, which may lead to development of novel strategies for prevention and treatment of obesity.
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Affiliation(s)
- Daisuke Aotani
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, and Department of Experimental Therapeutics, Translational Research Center, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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14
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Miyamoto L, Ebihara K, Kusakabe T, Aotani D, Yamamoto-Kataoka S, Sakai T, Aizawa-Abe M, Yamamoto Y, Fujikura J, Hayashi T, Hosoda K, Nakao K. Leptin activates hepatic 5'-AMP-activated protein kinase through sympathetic nervous system and α1-adrenergic receptor: a potential mechanism for improvement of fatty liver in lipodystrophy by leptin. J Biol Chem 2012; 287:40441-7. [PMID: 23024365 DOI: 10.1074/jbc.m112.384545] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND AMPK activation promotes glucose and lipid metabolism. RESULTS Hepatic AMPK activities were decreased in fatty liver from lipodystrophic mice, and leptin activated the hepatic AMPK via the α-adrenergic effect. CONCLUSION Leptin improved the fatty liver possibly by activating hepatic AMPK through the central and sympathetic nervous systems. SIGNIFICANCE Hepatic AMPK plays significant roles in the pathophysiology of lipodystrophy and metabolic action of leptin. Leptin is an adipocyte-derived hormone that regulates energy homeostasis. Leptin treatment strikingly ameliorates metabolic disorders of lipodystrophy, which exhibits ectopic fat accumulation and severe insulin-resistant diabetes due to a paucity of adipose tissue. Although leptin is shown to activate 5'-AMP-activated protein kinase (AMPK) in the skeletal muscle, the effect of leptin in the liver is still unclear. We investigated the effect of leptin on hepatic AMPK and its pathophysiological relevance in A-ZIP/F-1 mice, a model of generalized lipodystrophy. Here, we demonstrated that leptin activates hepatic AMPK through the central nervous system and α-adrenergic sympathetic nerves. AMPK activities were decreased in the fatty liver of A-ZIP/F-1 mice, and leptin administration increased AMPK activities in the liver as well as in skeletal muscle with significant reduction in triglyceride content. Activation of hepatic AMPK with A769662 also led to a decrease in hepatic triglyceride content and blood glucose levels in A-ZIP/F-1 mice. These results indicate that the down-regulation of hepatic AMPK activities plays a pathophysiological role in the metabolic disturbances of lipodystrophy, and the hepatic AMPK activation is involved in the therapeutic effects of leptin.
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Affiliation(s)
- Licht Miyamoto
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Kyoto 606-8507, Japan
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15
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Kusakabe T, Ebihara K, Sakai T, Miyamoto L, Aotani D, Yamamoto Y, Yamamoto-Kataoka S, Aizawa-Abe M, Fujikura J, Hosoda K, Nakao K. Amylin improves the effect of leptin on insulin sensitivity in leptin-resistant diet-induced obese mice. Am J Physiol Endocrinol Metab 2012; 302:E924-31. [PMID: 22275759 DOI: 10.1152/ajpendo.00198.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [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: 11/22/2022]
Abstract
Leptin enhances insulin sensitivity in addition to reducing food intake and body weight. Recently, amylin, a pancreatic β-cell-derived hormone, was shown to restore a weight-reducing effect of leptin in leptin-resistant diet-induced obesity. However, whether amylin improves the effect of leptin on insulin sensitivity in diet-induced obesity is unclear. Diet-induced obese (DIO) mice were infused with either saline (S), leptin (L; 500 μg·kg⁻¹·day⁻¹), amylin (A; 100 μg·kg⁻¹·day⁻¹), or leptin plus amylin (L/A) for 14 days using osmotic minipumps. Food intake, body weight, metabolic parameters, tissue triglyceride content, and AMP-activated protein kinase (AMPK) activity were examined. Pair-feeding and weight-matched calorie restriction experiments were performed to assess the influence of food intake and body weight reduction. Continuous L/A coadministration significantly reduced food intake, increased energy expenditure, and reduced body weight, whereas administration of L or A alone had no effects. L/A coadministration did not affect blood glucose levels during ad libitum feeding but decreased plasma insulin levels significantly (by 48%), suggesting the enhancement of insulin sensitivity. Insulin tolerance test actually showed the increased effect of insulin in L/A-treated mice. In addition, L/A coadministration significantly decreased tissue triglyceride content and increased AMPKα2 activity in skeletal muscle (by 67%). L/A coadministration enhanced insulin sensitivity more than pair-feeding and weight-matched calorie restriction. In conclusion, this study demonstrates the beneficial effect of L/A coadministration on glucose and lipid metabolism in DIO mice, indicating the possible clinical usefulness of L/A coadministration as a new antidiabetic treatment in obesity-associated diabetes.
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Affiliation(s)
- Toru Kusakabe
- Dept. of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
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16
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Aizawa-Abe M. [Role of hepatic insulin resistance in pathogenesis of metabolic syndrome]. Nihon Rinsho 2011; 69 Suppl 1:180-184. [PMID: 21766593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Megumi Aizawa-Abe
- Department of Experimental Medicine, Translational Research Center, Kyoto University Hospital
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17
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Satoh N, Shimatsu A, Yamada K, Aizawa-Abe M, Suganami T, Kuzuya H, Ogawa Y. An alpha-glucosidase inhibitor, voglibose, reduces oxidative stress markers and soluble intercellular adhesion molecule 1 in obese type 2 diabetic patients. Metabolism 2006; 55:786-93. [PMID: 16713439 DOI: 10.1016/j.metabol.2006.01.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [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] [Received: 10/05/2005] [Accepted: 01/08/2006] [Indexed: 11/26/2022]
Abstract
Postprandial hyperglycemia and hyperlipidemia are considered risk factors for cardiovascular disease. This study was designed to elucidate whether improving the postprandial state by voglibose, an alpha-glucosidase inhibitor, leads to the reduction of oxidative stress markers and soluble adhesion molecules in obese type 2 diabetic patients. A total of 30 Japanese obese type 2 diabetic patients were randomly assigned and treated for 3 weeks with either diet alone (the control group) or diet plus voglibose (0.9 mg daily) (the voglibose group) (n=15 each). Analysis of the diurnal metabolic profiles revealed a significant reduction of postprandial hyperglycemia and hyperlipidemia in the voglibose group relative to the control group (P<.05), despite the similar improvement in body mass index and hemoglobin A(1c) in both groups. Voglibose also decreased significantly the plasma levels of soluble intercellular adhesion molecule 1 and urinary excretion of 8-iso-prostaglandin F(2)alpha and 8-hydroxydeoxyguanosine (P<.01) and C-reactive protein (P<.05) relative to the control group. In conclusion, this study represents the first demonstration that voglibose reduces oxidative stress generation and soluble intercellular adhesion molecule 1 in parallel with the reduction of postprandial hyperglycemia and hyperlipidemia in obese type 2 diabetic patients.
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Affiliation(s)
- Noriko Satoh
- Clinical Research Institute for Endocrine Metabolic Disease, National Hospital Organization, Kyoto Medical Center, Fushimi-ku, Kyoto 612-8555, Japan
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18
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Masuzaki H, Ogawa Y, Aizawa-Abe M, Nakao K. Transgenic approach toward leptin biology: the clinical implications of leptin for the treatment of obesity-associated diabetes and obesity-related hypertension. Endocr J 2002; 49:109-19. [PMID: 12081228 DOI: 10.1507/endocrj.49.109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Hiroaki Masuzaki
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Sakyoku, Japan
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19
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Ogawa Y, Masuzaki H, Ebihara K, Shintani M, Aizawa-Abe M, Miyanaga F, Nakao K. Pathophysiogical role of leptin in lifestyle-related diseases. Studies with transgenic skinny mice overexpressing leptin. J Diabetes Complications 2002; 16:119-22. [PMID: 11872379 DOI: 10.1016/s1056-8727(01)00204-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [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: 11/25/2022]
Abstract
Leptin is a major adipocyte-derived hormone that is involved in the regulation of food intake and energy expenditure. Plasma leptin concentrations are elevated in obese subjects, suggesting its pathophysiological role in obesity-related lifestyle-related diseases. We have recently succeeded in the generation of transgenic skinny mice overexpressing leptin. They exhibit increased glucose metabolism and insulin sensitivity accompanied by a significant increase in insulin signaling for glucose utilization in the skeletal muscle and liver. They also show blood pressure elevation through the sympathetic activation. Introduction of the lethal yellow agouti (A(y)) allele into transgenic skinny mice results in late-onset obesity and diabetes with blood pressure elevation similar to those found in nontransgenic agouti mice (A(y)/+ mice). After caloric restriction, blood pressure elevation is reversed but insulin resistance still remains in A(y)/+ mice in parallel with a reduction of plasma leptin concentrations. By contrast, blood pressure elevation is sustained but insulin resistance is reversed in transgenic mice overexpressing leptin with the A(y) allele (Tg/+:A(y)/+ mice), which remain hyperleptinemic. Collectively, our data suggest the pathophysiologic and therapeutic implication of leptin in obesity-related insulin resistance and hypertension.
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Affiliation(s)
- Yoshihiro Ogawa
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin, Kawahara-cho, Sakyo-ku, 606-8507, Kyoto, Japan.
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20
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Ebihara K, Ogawa Y, Masuzaki H, Shintani M, Miyanaga F, Aizawa-Abe M, Hayashi T, Hosoda K, Inoue G, Yoshimasa Y, Gavrilova O, Reitman ML, Nakao K. Transgenic overexpression of leptin rescues insulin resistance and diabetes in a mouse model of lipoatrophic diabetes. Diabetes 2001; 50:1440-8. [PMID: 11375346 DOI: 10.2337/diabetes.50.6.1440] [Citation(s) in RCA: 167] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lipoatrophic diabetes is caused by a deficiency of adipose tissue and is characterized by severe insulin resistance, hypoleptinemia, and hyperphagia. The A-ZIP/F-1 mouse (A-ZIPTg/+) is a model of severe lipoatrophic diabetes and is insulin resistant, hypoleptinemic, hyperphagic, and shows severe hepatic steatosis. We have also produced transgenic "skinny" mice that have hepatic overexpression of leptin (LepTg/+) and no adipocyte triglyceride stores, and are hypophagic and show increased insulin sensitivity. To explore the pathophysiological and therapeutic roles of leptin in lipoatrophic diabetes, we crossed LepTg/+ and A-ZIPTg/+ mice, producing doubly transgenic mice (LepTg/+:A-ZIPTg/+) virtually lacking adipose tissue but having greatly elevated leptin levels. The LepTg/+:A-ZIPTg/+ mice were hypophagic and showed improved hepatic steatosis. Glucose and insulin tolerance tests revealed increased insulin sensitivity, comparable to LepTg/+ mice. These effects were stable over at least 6 months of age. Pair-feeding the A-ZIPTg/+ mice to the amount of food consumed by LepTg/+:A-ZIPTg/+ mice did not improve their insulin resistance, diabetes, or hepatic steatosis, demonstrating that the beneficial effects of leptin were not due to the decreased food intake. Continuous leptin administration that elevates plasma leptin concentrations to those of LepTg/+:A-ZIPTg/+ mice also effectively improved hepatic steatosis and the disorder of glucose and lipid metabolism in A-ZIP/F-1 mice. These data demonstrate that leptin can improve the insulin resistance and diabetes of a mouse model of severe lipoatrophic diabetes, suggesting that leptin may be therapeutically useful in the long-term treatment of lipoatrophic diabetes.
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Affiliation(s)
- K Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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21
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Shintani M, Ogawa Y, Ebihara K, Aizawa-Abe M, Miyanaga F, Takaya K, Hayashi T, Inoue G, Hosoda K, Kojima M, Kangawa K, Nakao K. Ghrelin, an endogenous growth hormone secretagogue, is a novel orexigenic peptide that antagonizes leptin action through the activation of hypothalamic neuropeptide Y/Y1 receptor pathway. Diabetes 2001; 50:227-32. [PMID: 11272130 DOI: 10.2337/diabetes.50.2.227] [Citation(s) in RCA: 626] [Impact Index Per Article: 27.2] [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: 01/11/2023]
Abstract
Ghrelin, an endogenous ligand for growth hormone secretagogue (GHS) receptor originally isolated from the stomach, occurs in the hypothalamic arcuate nucleus and may play a role in energy homeostasis. Synthetic GHSs have activated the hypothalamic arcuate neurons containing neuropeptide Y (NPY), suggesting the involvement of NPY in some of ghrelin actions. This study was designed to elucidate the role of ghrelin in the regulation of food intake. A single intracerebroventricular (ICV) injection of ghrelin (5-5,000 ng/rat) caused a significant and dose-related increase in cumulative food intake in rats. Ghrelin (500 ng/rat) was also effective in growth hormone-deficient spontaneous dwarf rats. Hypothalamic NPY mRNA expression was increased in rats that received a single ICV injection of ghrelin (500 ng/rat) (approximately 160% of that in vehicle-treated groups, P < 0.05). The ghrelin's orexigenic effect was abolished dose-dependently by ICV co-injection of NPY Y1 receptor antagonist (10-30 microg/rat). The leptin-induced inhibition of food intake was reversed by ICV co-injection of ghrelin in a dose-dependent manner (5-500 ng/rat). Leptin reduced hypothalamic NPY mRNA expression by 35% (P < 0.05), which was abolished by ICV co-injection of ghrelin (500 ng/rat). This study provides evidence that ghrelin is an orexigenic peptide that antagonizes leptin action through the activation of hypothalamic NPY/Y1 receptor pathway.
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Affiliation(s)
- M Shintani
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan
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Matsuoka N, Ogawa Y, Masuzaki H, Ebihara K, Aizawa-Abe M, Satoh N, Ishikawa E, Fujisawa Y, Kosaki A, Yamada K, Kuzuya H, Nakao K. Decreased triglyceride-rich lipoproteins in transgenic skinny mice overexpressing leptin. Am J Physiol Endocrinol Metab 2001; 280:E334-9. [PMID: 11158938 DOI: 10.1152/ajpendo.2001.280.2.e334] [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: 11/22/2022]
Abstract
Leptin is an adipocyte-derived circulating satiety factor with a variety of biological effects. Evidence has accumulated suggesting that leptin may modulate glucose and lipid metabolism. In the present study, we examined lipid metabolism in transgenic skinny mice with elevated plasma leptin concentrations. The plasma concentrations of triglycerides and free fatty acids in transgenic skinny mice were 71.5 (P < 0.01) and 89.1% (P < 0.05) of those in their nontransgenic littermates, respectively. Separation of plasma into lipoprotein classes by ultracentrifugation revealed that very low density lipoprotein-triglyceride concentrations were markedly reduced in transgenic skinny mice relative to the controls. The clearance of triglycerides estimated by a fat-loading test was enhanced in transgenic skinny mice; the triglyceride concentration in transgenic skinny mice 3 h after fat loading was 39.7% (P < 0.05) of that of their nontransgenic littermates. Postheparin plasma lipoprotein lipase activity increased 1.4-fold (P < 0.05) in transgenic skinny mice. Our data demonstrated a significant reduction in plasma triglyceride concentrations, accompanied by increased lipoprotein lipase activity in transgenic skinny mice overexpressing leptin, suggesting that leptin plays a role in long-term triglyceride metabolism.
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Affiliation(s)
- N Matsuoka
- Diabetes Center and Clinical Research Institute of Kyoto National Hospital, Kyoto 612-8555, Japan
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Aizawa-Abe M, Ogawa Y, Masuzaki H, Ebihara K, Satoh N, Iwai H, Matsuoka N, Hayashi T, Hosoda K, Inoue G, Yoshimasa Y, Nakao K. Pathophysiological role of leptin in obesity-related hypertension. J Clin Invest 2000; 105:1243-52. [PMID: 10791999 PMCID: PMC315441 DOI: 10.1172/jci8341] [Citation(s) in RCA: 364] [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: 11/17/2022] Open
Abstract
To explore the pathophysiological role of leptin in obesity-related hypertension, we examined cardiovascular phenotypes of transgenic skinny mice whose elevated plasma leptin concentrations are comparable to those seen in obese subjects. We also studied genetically obese KKA(y) mice with hyperleptinemia, in which hypothalamic melanocortin system is antagonized by ectopic expression of the agouti protein. Systolic blood pressure (BP) and urinary catecholamine excretion are elevated in transgenic skinny mice relative to nontransgenic littermates. The BP elevation in transgenic skinny mice is abolished by alpha(1)-adrenergic, beta-adrenergic, or ganglionic blockers at doses that do not affect BP in nontransgenic littermates. Central administration of an alpha-melanocyte-stimulating hormone antagonist causes a marked increase in cumulative food intake but no significant changes in BP. The obese KKA(y) mice develop BP elevation with increased urinary catecholamine excretion relative to control KK mice. After a 2-week caloric restriction, BP elevation is reversed in nontransgenic littermates with the A(y) allele, in parallel with a reduction in plasma leptin concentrations, but is sustained in transgenic mice overexpressing leptin with the A(y) allele, which remain hyperleptinemic. This study demonstrates BP elevation in transgenic skinny mice and obese KKA(y) mice that are both hyperleptinemic, thereby suggesting the pathophysiological role of leptin in some forms of obesity-related hypertension.
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Affiliation(s)
- M Aizawa-Abe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
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Yura S, Ogawa Y, Sagawa N, Masuzaki H, Itoh H, Ebihara K, Aizawa-Abe M, Fujii S, Nakao K. Accelerated puberty and late-onset hypothalamic hypogonadism in female transgenic skinny mice overexpressing leptin. J Clin Invest 2000; 105:749-55. [PMID: 10727443 PMCID: PMC377463 DOI: 10.1172/jci8353] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [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: 01/25/2023] Open
Abstract
Excess or loss of body fat can be associated with infertility, suggesting that adequate fat mass is essential for proper reproductive function. Leptin is an adipocyte-derived hormone that is involved in the regulation of food intake and energy expenditure, and its synthesis and secretion are markedly increased in obesity. Short-term administration of leptin accelerates the onset of puberty in normal mice and corrects the sterility of leptin-deficient ob/ob mice. These findings suggest a role for leptin as an endocrine signal between fat depots and the reproductive axis, but the effect of hyperleptinemia on the initiation and maintenance of reproductive function has not been elucidated. To address this issue, we examined the reproductive phenotypes of female transgenic skinny mice with elevated plasma leptin concentrations comparable to those in obese subjects. With no apparent adipose tissue, female transgenic skinny mice exhibit accelerated puberty and intact fertility at younger ages followed by successful delivery of healthy pups. However, at older ages, they develop hypothalamic hypogonadism characterized by prolonged menstrual cycles, atrophic ovary, reduced hypothalamic gonadotropin releasing hormone contents, and poor pituitary luteinizing hormone secretion. This study has demonstrated for the first time to our knowledge that accelerated puberty and late-onset hypothalamic hypogonadism are associated with chronic hyperleptinemia, thereby leading to a better understanding of the pathophysiological and therapeutic implication of leptin.
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Affiliation(s)
- S Yura
- Department of Gynecology and Obstetrics, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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25
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Aizawa-Abe M, Ogawa Y, Masuzaki H, Nakao K. [Ob gene]. Nihon Rinsho 2000; 58 Suppl 1:551-5. [PMID: 11026331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- M Aizawa-Abe
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine
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26
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Ebihara K, Ogawa Y, Katsuura G, Numata Y, Masuzaki H, Satoh N, Tamaki M, Yoshioka T, Hayase M, Matsuoka N, Aizawa-Abe M, Yoshimasa Y, Nakao K. Involvement of agouti-related protein, an endogenous antagonist of hypothalamic melanocortin receptor, in leptin action. Diabetes 1999; 48:2028-33. [PMID: 10512369 DOI: 10.2337/diabetes.48.10.2028] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [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] [Indexed: 11/13/2022]
Abstract
To understand the role of agouti-related protein (AGRP), an endogenous antagonist of hypothalamic melanocortin receptor, in leptin action, we produced a full-length recombinant AGRP and examined its effect on the satiety effect of leptin. We also studied leptin's regulation of hypothalamic AGRP mRNA expression. A single intracerebroventricular (i.c.v.) injection of AGRP significantly increased cumulative food intake and body weight in a dose-dependent manner in rats. The leptin-induced inhibition of food intake and body weight was reversed by co-injection of AGRP in a dose-dependent manner. Hypothalamic AGRP mRNA expression was upregulated in leptin-deficient ob/ob mice and leptin receptor-deficient db/db mice and downregulated in lethal yellow agouti mice (KKAy mice) with hyperleptinemia. A single i.c.v. injection of leptin reversed the increased AGRP mRNA levels in ob/ob mice but not in db/db mice. In control mice and KKAy mice, AGRP mRNA expression was upregulated during fasting, when plasma leptin concentrations were decreased. No significant increase in AGRP mRNA expression was noted during fasting in control mice and KKAy mice treated with leptin. This study provides the first direct evidence that AGRP is a negative regulator of leptin action, and leptin downregulates hypothalamic AGRP production. Because leptin is shown to increase hypothalamic alpha-melanocyte stimulating hormone (alpha-MSH) production, our data suggest that its action via the hypothalamic melanocortin system is determined by the balance between the levels of its agonist and antagonist, alpha-MSH and AGRP.
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MESH Headings
- Agouti-Related Protein
- Animals
- Chromatography, High Pressure Liquid
- Electrophoresis, Polyacrylamide Gel
- Hypothalamus/metabolism
- Injections, Intraventricular
- Intercellular Signaling Peptides and Proteins
- Leptin
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Obese
- Molecular Sequence Data
- Proteins/administration & dosage
- Proteins/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Corticotropin/metabolism
- Receptors, Leptin
- Receptors, Melanocortin
- Recombinant Proteins/metabolism
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Affiliation(s)
- K Ebihara
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan
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Ogawa Y, Masuzaki H, Hosoda K, Aizawa-Abe M, Suga J, Suda M, Ebihara K, Iwai H, Matsuoka N, Satoh N, Odaka H, Kasuga H, Fujisawa Y, Inoue G, Nishimura H, Yoshimasa Y, Nakao K. Increased glucose metabolism and insulin sensitivity in transgenic skinny mice overexpressing leptin. Diabetes 1999; 48:1822-9. [PMID: 10480614 DOI: 10.2337/diabetes.48.9.1822] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.4] [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] [Indexed: 12/16/2022]
Abstract
Excess of body fat, or obesity, is a major health problem and confers a higher risk of cardiovascular and metabolic disorders such as diabetes, hypertension, and coronary heart disease. Leptin is an adipocyte-derived satiety factor that plays an important role in the regulation of energy homeostasis, and its synthesis and secretion are markedly increased in obese subjects. To explore the metabolic consequences of an increased amount of leptin on a long-term basis in vivo, we generated transgenic skinny mice with elevated plasma leptin concentrations comparable to those in obese subjects. Overexpression of leptin in the liver has resulted in complete disappearance of white and brown adipose tissue for a long period of time in mice. Transgenic skinny mice exhibit increased glucose metabolism accompanied by the activation of insulin signaling in the skeletal muscle and liver. They also show small-sized livers with a marked decrease in glycogen and lipid storage. The phenotypes are in striking contrast to those of recently reported animal models of lipoatrophic diabetes and patients with lipoatrophic diabetes with reduced amount of leptin. The present study provides evidence that leptin is an adipocyte-derived antidiabetic hormone in vivo and suggests its pathophysiologic and therapeutic implications in diabetes.
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Affiliation(s)
- Y Ogawa
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan.
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28
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Masuzaki H, Ogawa Y, Aizawa-Abe M, Hosoda K, Suga J, Ebihara K, Satoh N, Iwai H, Inoue G, Nishimura H, Yoshimasa Y, Nakao K. Glucose metabolism and insulin sensitivity in transgenic mice overexpressing leptin with lethal yellow agouti mutation: usefulness of leptin for the treatment of obesity-associated diabetes. Diabetes 1999; 48:1615-22. [PMID: 10426381 DOI: 10.2337/diabetes.48.8.1615] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [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: 11/13/2022]
Abstract
Leptin acts as an adipocyte-derived blood-borne satiety factor that can increase glucose metabolism. To elucidate the therapeutic implications of leptin for obesity-associated diabetes, we crossed transgenic skinny mice overexpressing leptin (Tg/+), which we have developed recently, and lethal yellow KKAy mice (Ay/+), a genetic model for obesity-diabetes syndrome, and examined the metabolic phenotypes of F1 animals. At 6 weeks of age, plasma leptin concentrations in Tg/+ mice with the Ay allele (Tg/+:Ay/+) were significantly higher than those in Ay/+ mice. Although no significant differences in body weight were noted among Tg/+:Ay/+ mice, Ay/+ mice, and their wild-type lean littermates (+/+), glucose and insulin tolerance tests revealed increased glucose tolerance and insulin sensitivity in Tg/+:Ay/+ compared with Ay/+ mice. However, at 12 weeks of age, when plasma leptin concentrations in Ay/+ mice were comparable to those in Tg/+:Ay/+ mice, Tg/+:Ay/+ mice developed obesity-diabetes syndrome similar to that of Ay/+ mice. Body weights of 12-week-old Tg/+:Ay/+ and Ay/+ mice were reduced to those of +/+ mice by a 3-week food restriction; when plasma leptin concentrations remained high in Tg/+:Ay/+ mice but were markedly reduced in Ay/+ and +/+ mice, glucose tolerance and insulin sensitivity in Tg/+:Ay/+ mice were markedly improved as compared with Ay/+ and +/+ mice. The present study demonstrates that hyperleptinemia can delay the onset of impaired glucose metabolism and accelerate the recovery from diabetes during caloric restriction in Tg/+:Ay/+ mice, thereby suggesting the potential usefulness of leptin in combination with a long-term caloric restriction for the treatment of obesity-associated diabetes.
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Affiliation(s)
- H Masuzaki
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan
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