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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: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [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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Nomura H, Son C, Aotani D, Shimizu Y, Katsuura G, Noguchi M, Kusakabe T, Tanaka T, Miyazawa T, Hosoda K, Nakao K. Impaired leptin responsiveness in the nucleus accumbens of leptin-overexpressing transgenic mice with dysregulated sucrose and lipid preference independent of obesity. Neurosci Res 2021; 177:94-102. [PMID: 34971637 DOI: 10.1016/j.neures.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 12/06/2021] [Accepted: 12/26/2021] [Indexed: 11/19/2022]
Abstract
While hypothalamic leptin resistance can occur prior to establishment of obesity, clarification is needed as to whether the impaired response to leptin in the reward-related nuclei occurs independently of obesity. To answer this question, we attempted to dissociate the normally coexisting leptin resistance from obesity. We investigated phenotypes of leptin-overexpressing transgenic mice fed for 1 week with 60 % high-fat diet (HFD) (LepTg-HFD1W mice). After 1 week, we observed that LepTg-HFD1W mice weighed as same as wild type (WT) mice fed standard chow diet (CD) for 1 week (WT-CD1W mice). However, compared to WT-CD1W mice, LepTg-HFD1W mice exhibited attenuated leptin-induced anorexia, decreased leptin-induced c-fos immunostaining in nucleus accumbens (NAc), one of important site of reward system, decreased leptin-stimulated pSTAT3 immunostaining in hypothalamus. Furthermore, neither sucrose nor lipid preference was suppressed by leptin in LepTg-HFD1W mice. On the contrary, leptin significantly suppressed both preferences in WT mice fed HFD (WT-HFD1 W mice). These results indicate that leptin responsiveness decreases in NAc independently of obesity. Additionally, in this situation, suppressive effect of leptin on the hedonic feeding results in impaired regulation. Such findings suggest the impaired leptin responsiveness in NAc partially contributes to dysregulated hedonic feeding behavior independently of obesity.
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Affiliation(s)
- Hidenari Nomura
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Cheol Son
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan; Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Japan.
| | - Daisuke Aotani
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshiyuki Shimizu
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Human Health and Science, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Goro Katsuura
- Department of Social and Behavioral Medicine, Division of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Michio Noguchi
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toru Kusakabe
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomohiro Tanaka
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takashi Miyazawa
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Department of Human Health and Science, 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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Szpirer C. Rat models of human diseases and related phenotypes: a systematic inventory of the causative genes. J Biomed Sci 2020; 27:84. [PMID: 32741357 PMCID: PMC7395987 DOI: 10.1186/s12929-020-00673-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
The laboratory rat has been used for a long time as the model of choice in several biomedical disciplines. Numerous inbred strains have been isolated, displaying a wide range of phenotypes and providing many models of human traits and diseases. Rat genome mapping and genomics was considerably developed in the last decades. The availability of these resources has stimulated numerous studies aimed at discovering causal disease genes by positional identification. Numerous rat genes have now been identified that underlie monogenic or complex diseases and remarkably, these results have been translated to the human in a significant proportion of cases, leading to the identification of novel human disease susceptibility genes, helping in studying the mechanisms underlying the pathological abnormalities and also suggesting new therapeutic approaches. In addition, reverse genetic tools have been developed. Several genome-editing methods were introduced to generate targeted mutations in genes the function of which could be clarified in this manner [generally these are knockout mutations]. Furthermore, even when the human gene causing a disease had been identified without resorting to a rat model, mutated rat strains (in particular KO strains) were created to analyze the gene function and the disease pathogenesis. Today, over 350 rat genes have been identified as underlying diseases or playing a key role in critical biological processes that are altered in diseases, thereby providing a rich resource of disease models. This article is an update of the progress made in this research and provides the reader with an inventory of these disease genes, a significant number of which have similar effects in rat and humans.
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Affiliation(s)
- Claude Szpirer
- Université Libre de Bruxelles, B-6041, Gosselies, Belgium.
- , Waterloo, Belgium.
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Izumi R, Kusakabe T, Noguchi M, Iwakura H, Tanaka T, Miyazawa T, Aotani D, Hosoda K, Kangawa K, Nakao K. CRISPR/Cas9-mediated Angptl8 knockout suppresses plasma triglyceride concentrations and adiposity in rats. J Lipid Res 2018; 59:1575-1585. [PMID: 30042156 DOI: 10.1194/jlr.m082099] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 07/22/2018] [Indexed: 12/14/2022] Open
Abstract
Angiopoietin-like protein (ANGPTL)8 is a liver- and adipocyte-derived protein that controls plasma triglyceride (TG) levels. Most animal studies have used mouse models. Here, we generated an Angptl8 KO rat model using a clustered regulatory interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) system to clarify the roles of ANGPTL8 in glucose and lipid metabolism. Compared with WT rats, Angptl8 KO rats had lower body weight and fat content, associated with impaired lipogenesis in adipocytes; no differences existed between the groups in food intake or rectal temperature. Plasma TG levels in both the fasted and refed states were significantly lower in KO than in WT rats, and an oral fat tolerance test showed decreased plasma TG excursion in Angptl8 KO rats. Higher levels of lipase activity in the heart and greater expression of genes related to β-oxidation in heart and skeletal muscle were observed in Angptl8 KO rats. However, there were no significant differences between KO and WT rats in glucose metabolism or the histology of pancreatic β-cells on both standard and high-fat diets. In conclusion, we demonstrated that Angptl8 KO in rats resulted in lower body weight and plasma TG levels without affecting glucose metabolism. ANGPTL8 might be an important therapeutic target for obesity and dyslipidemia.
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Affiliation(s)
- Ryota Izumi
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Diabetes, Endocrinology, and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toru Kusakabe
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Endocrinology, Metabolism, and Hypertension, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
| | - Michio Noguchi
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Iwakura
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomohiro Tanaka
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takashi Miyazawa
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Aotani
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kiminori Hosoda
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan; Division of Endocrinology and Metabolism, Department of Lifestyle-Related Diseases, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Kenji Kangawa
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan; National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Kazuwa Nakao
- Medical Innovation Center Kyoto University Graduate School of Medicine, Kyoto, Japan
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Guan L, Xu K, Xu S, Li N, Wang X, Xia Y, Wu D. Profiles of metabolic gene expression in the white adipose tissue, liver and hypothalamus in leptin knockout (Lep ΔI14/ΔI14 ) rats. J Biomed Res 2017; 31:528. [PMID: 28866659 PMCID: PMC6307666 DOI: 10.7555/jbr.31.20170021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 03/30/2017] [Indexed: 12/28/2022] Open
Abstract
Leptin deficiency is principally linked to metabolic disorders. Leptin knockout (LepΔI14/ΔI14) Sprague Dawley rats created by CRISPR/Cas9 is a new model to study metabolic disorders. We used a whole rat genome oligonucleotide microarray to obtain tissue-specific gene expression profiles of the white adipose tissue, liver and hypothalamus in LepΔI14/ΔI14 and wild-type (WT) rats. We found 1,651 differentially expressed (enriched) genes in white adipose tissue, 916 in the liver, and 306 in the hypothalamus in the LepΔI14/ΔI14 rats compared to WT. Gene ontology category and KEGG pathway analysis of the relationships among differentially expressed genes showed that these genes were represented in a variety of functional categories, including fatty acid metabolism, molecular transducers and cellular processes. The reliability of the data obtained from microarray was verified by quantitative real-time PCR on 14 representative genes. These data will contribute to a greater understanding of different metabolic disorders, such as obesity and diabetes.
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Affiliation(s)
- Leijian Guan
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Kaixuan Xu
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
- . Xuzhou Central Hospital, The Affiliated Xuzhou Hospital of Medical College of Southeast University, Xuzhou, Jiangsu 221009, China
| | - Shuyang Xu
- . School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Ningning Li
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Xinru Wang
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Yankai Xia
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Di Wu
- . State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
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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] [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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D'souza AM, Johnson JD, Clee SM, Kieffer TJ. Suppressing hyperinsulinemia prevents obesity but causes rapid onset of diabetes in leptin-deficient Lepob/ob mice. Mol Metab 2016; 5:1103-1112. [PMID: 27818936 PMCID: PMC5081422 DOI: 10.1016/j.molmet.2016.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/11/2016] [Accepted: 09/14/2016] [Indexed: 12/27/2022] Open
Abstract
Objective Hyperinsulinemia is commonly associated with obesity. Mice deficient in the adipose-derived hormone leptin (Lepob/ob) develop hyperinsulinemia prior to onset of obesity and glucose intolerance. Whether the excess of circulating insulin is a major contributor to obesity and impaired glucose homeostasis in Lepob/ob mice is unclear. It has been reported previously that diet-induced obesity in mice can be prevented by reducing insulin gene dosage. In the present study, we examined the effects of genetic insulin reduction in Lepob/ob mice on circulating insulin, body composition, and glucose homeostasis. Methods Leptin expressing (Lepwt/wt) mice lacking 3 insulin alleles were crossed with Lepob/ob mice to generate Lepob/ob and Lepwt/wt littermates lacking 1 (Ins1+/+;Ins2+/−), 2 (Ins1+/+;Ins2−/−) or 3 (Ins1+/−;Ins2−/−) insulin alleles. Animals were assessed for body weight gain, body composition, glucose homeostasis, and islet morphology. Results We found that in young Lepob/ob mice, loss of 2 or 3 insulin alleles reduced plasma insulin levels by 75–95% and attenuated body weight gain by 50–90% compared to Ins1+/+;Ins2+/−;Lepob/ob mice. This corresponded with ∼30% and ∼50% reduced total body fat in Ins1+/+;Ins2−/−;Lepob/ob and Ins1+/−;Ins2−/−;Lepob/ob mice, respectively. Loss of 2 or 3 insulin alleles in young Lepob/ob mice resulted in onset of fasting hyperglycemia by 4 weeks of age, exacerbated glucose intolerance, and abnormal islet morphology. In contrast, loss of 1,2 or 3 insulin alleles in Lepwt/wt mice did not significantly alter plasma insulin levels, body weight, fat mass, fasting glycemia, or glucose tolerance. Conclusion Taken together, our findings indicate that hyperinsulinemia is required for excess adiposity in Lepob/ob mice and sufficient insulin production is necessary to maintain euglycemia in the absence of leptin. Loss of 2 or 3 insulin alleles results in a dose dependent decrease of circulating insulin levels and body fat in Lepob/ob mice. Loss of 2 or 3 insulin alleles produced a greater reduction in body weight in male as compared to female Lepob/ob mice. Attenuation of hyperinsulinemia accelerates onset of hyperglycemia in Lepob/ob mice.
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Affiliation(s)
- Anna M D'souza
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Susanne M Clee
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Surgery, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
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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] [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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D'souza AM, Asadi A, Johnson JD, Covey SD, Kieffer TJ. Leptin deficiency in rats results in hyperinsulinemia and impaired glucose homeostasis. Endocrinology 2014; 155:1268-79. [PMID: 24467741 DOI: 10.1210/en.2013-1523] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Leptin, an adipocyte-derived hormone, has well-established anorexigenic effects but is also able to regulate glucose homeostasis independent of body weight. Until recently, the ob/ob mouse was the only animal model of global leptin deficiency. Here we report the effects of leptin deficiency on glucose homeostasis in male and female leptin knockout (KO) rats. Leptin KO rats developed obesity by 6 to 7 weeks of age, and lipid mass was increased by more than 2-fold compared with that of wild-type (WT) littermates at 18 weeks of age. Hyperinsulinemia and insulin resistance were evident in both males and females and were sustained with aging. Male KO rats experienced transient mild fasting hyperglycemia between 14 and 25 weeks of age, but thereafter fasting glucose levels were comparable to those of WT littermates up to 36 weeks of age. Fasting glucose levels of female KO rats were similar to those of WT littermates. Male KO rats exhibited a 3-fold increase in the proportion of β-cell area relative to total pancreas at 36 weeks of age. Islets from 12-week-old KO rats secreted more insulin when stimulated than islets from WT littermates. Leptin replacement via miniosmotic pump (100 μg/d) reduced food intake, attenuated weight gain, normalized glucose tolerance, and improved glucose-stimulated insulin secretion and insulin sensitivity. Together, these data demonstrate that the absence of leptin in rats recapitulates some of the phenotype previously observed in ob/ob mice including development of hyperinsulinemia, obesity, and insulin resistance.
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Affiliation(s)
- Anna M D'souza
- Department of Cellular and Physiological Sciences (A.M.D., A.A., J.D.J., T.J.K.), Department of Biochemistry and Molecular Biology (S.D.C.), and Department of Surgery (J.D.J., T.J.K.), University of British Columbia, Vancouver British Columbia, Canada V5Z 4E3
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Ricketts T, McGoldrick P, Fratta P, de Oliveira HM, Kent R, Phatak V, Brandner S, Blanco G, Greensmith L, Acevedo-Arozena A, Fisher EMC. A nonsense mutation in mouse Tardbp affects TDP43 alternative splicing activity and causes limb-clasping and body tone defects. PLoS One 2014; 9:e85962. [PMID: 24465814 PMCID: PMC3897576 DOI: 10.1371/journal.pone.0085962] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 12/03/2013] [Indexed: 12/11/2022] Open
Abstract
Mutations in TARDBP, encoding Tar DNA binding protein-43 (TDP43), cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Attempts to model TDP43 dysfunction in mice have used knockouts or transgenic overexpressors, which have revealed the difficulties of manipulating TDP43, whose level is tightly controlled by auto-regulation. In a complementary approach, to create useful mouse models for the dissection of TDP43 function and pathology, we have identified a nonsense mutation in the endogenous mouse Tardbp gene through screening an N-ethyl-N-nitrosourea (ENU) mutant mouse archive. The mutation is predicted to cause a Q101X truncation in TDP43. We have characterised Tardbp(Q101X) mice to investigate this mutation in perturbing TDP43 biology at endogenous expression levels. We found the Tardbp(Q101X) mutation is homozygous embryonic lethal, highlighting the importance of TDP43 in early development. Heterozygotes (Tardbp(+/Q101X) ) have abnormal levels of mutant transcript, but we find no evidence of the truncated protein and mice have similar full-length TDP43 protein levels as wildtype littermates. Nevertheless, Tardbp(+/Q101X) mice have abnormal alternative splicing of downstream gene targets, and limb-clasp and body tone phenotypes. Thus the nonsense mutation in Tardbp causes a mild loss-of-function phenotype and behavioural assessment suggests underlying neurological abnormalities. Due to the role of TDP43 in ALS, we investigated potential interactions with another known causative gene, mutant superoxide dismutase 1 (SOD1). Tardbp(+/Q101X) mice were crossed with the SOD1(G93Adl) transgenic mouse model of ALS. Behavioural and physiological assessment did not reveal modifying effects on the progression of ALS-like symptoms in the double mutant progeny from this cross. In summary, the Tardbp(Q101X) mutant mice are a useful tool for the dissection of TDP43 protein regulation, effects on splicing, embryonic development and neuromuscular phenotypes. These mice are freely available to the community.
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Affiliation(s)
- Thomas Ricketts
- MRC Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
- Department of Neurodegenerative Diseases and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | - Philip McGoldrick
- Sobell Department of Motor Neuroscience and Movement Disorders and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | - Pietro Fratta
- Department of Neurodegenerative Diseases and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | | | - Rosie Kent
- MRC Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
| | - Vinaya Phatak
- MRC Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
| | - Sebastian Brandner
- Department of Neurodegenerative Diseases and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | - Gonzalo Blanco
- Biology Department, University of York, York, United Kingdom
| | - Linda Greensmith
- Sobell Department of Motor Neuroscience and Movement Disorders and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
- * E-mail: (LG); (AA-A); (EF)
| | - Abraham Acevedo-Arozena
- MRC Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
- * E-mail: (LG); (AA-A); (EF)
| | - Elizabeth M. C. Fisher
- MRC Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
- Department of Neurodegenerative Diseases and MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
- * E-mail: (LG); (AA-A); (EF)
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