1
|
Chua D, Low ZS, Cheam GX, Ng AS, Tan NS. Utility of Human Relevant Preclinical Animal Models in Navigating NAFLD to MAFLD Paradigm. Int J Mol Sci 2022; 23:ijms232314762. [PMID: 36499091 PMCID: PMC9737809 DOI: 10.3390/ijms232314762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Fatty liver disease is an emerging contributor to disease burden worldwide. The past decades of work established the heterogeneous nature of non-alcoholic fatty liver disease (NAFLD) etiology and systemic contributions to the pathogenesis of the disease. This called for the proposal of a redefinition in 2020 to that of metabolic dysfunction-associated fatty liver disease (MAFLD) to better reflect the current understanding of the disease. To date, several clinical cohort studies comparing NAFLD and MAFLD hint at the relevancy of the new nomenclature in enriching for patients with more severe hepatic injury and extrahepatic comorbidities. However, the underlying systemic pathogenesis is still not fully understood. Preclinical animal models have been imperative in elucidating key biological mechanisms in various contexts, including intrahepatic disease progression, interorgan crosstalk and systemic dysregulation. Furthermore, they are integral in developing novel therapeutics against MAFLD. However, substantial contextual variabilities exist across different models due to the lack of standardization in several aspects. As such, it is crucial to understand the strengths and weaknesses of existing models to better align them to the human condition. In this review, we consolidate the implications arising from the change in nomenclature and summarize MAFLD pathogenesis. Subsequently, we provide an updated evaluation of existing MAFLD preclinical models in alignment with the new definitions and perspectives to improve their translational relevance.
Collapse
Affiliation(s)
- Damien Chua
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore
- Correspondence: (D.C.); (N.S.T.); Tel.: +65-63162941 (N.S.T.); Fax: +65-67913856 (N.S.T.)
| | - Zun Siong Low
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore
| | - Guo Xiang Cheam
- School of Biological Sciences, Nanyang Technological University Singapore, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Aik Seng Ng
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Nguan Soon Tan
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore
- School of Biological Sciences, Nanyang Technological University Singapore, 60 Nanyang Drive, Singapore 637551, Singapore
- Correspondence: (D.C.); (N.S.T.); Tel.: +65-63162941 (N.S.T.); Fax: +65-67913856 (N.S.T.)
| |
Collapse
|
2
|
Piper NBC, Whitfield EA, Stewart GD, Xu X, Furness SGB. Targeting appetite and satiety in diabetes and obesity, via G protein-coupled receptors. Biochem Pharmacol 2022; 202:115115. [PMID: 35671790 DOI: 10.1016/j.bcp.2022.115115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/17/2022]
Abstract
Type 2 diabetes and obesity have reached pandemic proportions throughout the world, so much so that the World Health Organisation coined the term "Globesity" to help encapsulate the magnitude of the problem. G protein-coupled receptors (GPCRs) are highly tractable drug targets due to their wide involvement in all aspects of physiology and pathophysiology, indeed, GPCRs are the targets of approximately 30% of the currently approved drugs. GPCRs are also broadly involved in key physiologies that underlie type 2 diabetes and obesity including feeding reward, appetite and satiety, regulation of blood glucose levels, energy homeostasis and adipose function. Despite this, only two GPCRs are the target of approved pharmaceuticals for treatment of type 2 diabetes and obesity. In this review we discuss the role of these, and select other candidate GPCRs, involved in various facets of type 2 diabetic or obese pathophysiology, how they might be targeted and the potential reasons why pharmaceuticals against these targets have not progressed to clinical use. Finally, we provide a perspective on the current development pipeline of anti-obesity drugs that target GPCRs.
Collapse
Affiliation(s)
- Noah B C Piper
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Emily A Whitfield
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Gregory D Stewart
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Sebastian G B Furness
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia; Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia.
| |
Collapse
|
3
|
Ochi R, Fujita N, Takaishi K, Oshima T, Nguyen ST, Nishijo H, Urakawa S. Voluntary exercise reverses social behavior deficits and the increases in the densities of cholecystokinin-positive neurons in specific corticolimbic regions of diabetic OLETF rats. Behav Brain Res 2022; 428:113886. [DOI: 10.1016/j.bbr.2022.113886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022]
|
4
|
Ochi R, Fujita N, Goto N, Takaishi K, Oshima T, Nguyen ST, Nishijo H, Urakawa S. Medial prefrontal area reductions, altered expressions of cholecystokinin, parvalbumin, and activating transcription factor 4 in the corticolimbic system, and altered emotional behavior in a progressive rat model of type 2 diabetes. PLoS One 2021; 16:e0256655. [PMID: 34506507 PMCID: PMC8432800 DOI: 10.1371/journal.pone.0256655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/11/2021] [Indexed: 12/14/2022] Open
Abstract
Metabolic disorders are associated with a higher risk of psychiatric disorders. We previously reported that 20-week-old Otsuka Long-Evans Tokushima fatty (OLETF) rats, a model of progressive type 2 diabetes, showed increased anxiety-like behavior and regional area reductions and increased cholecystokinin-positive neurons in the corticolimbic system. However, in which stages of diabetes these alterations in OLETF rats occur remains unclear. We aimed to investigate anxiety-like behavior and its possible mechanisms at different stages of type 2 diabetes in OLETF rats. Eight- and 30-week-old OLETF rats were used as diabetic animal models at the prediabetic and progressive stages of type 2 diabetes respectively, and age-matched Long-Evans Tokushima Otsuka rats served as non-diabetic controls. In the open-field test, OLETF rats showed less locomotion in the center zone and longer latency to leave the center zone at 8 and 30 weeks old, respectively. The areas of the medial prefrontal cortex were smaller in the OLETF rats, regardless of age. The densities of cholecystokinin-positive neurons in OLETF rats were higher in the lateral and basolateral amygdala only at 8 weeks old and in the anterior cingulate and infralimbic cortices and hippocampal cornu ammonis area 3 at both ages. The densities of parvalbumin-positive neurons of OLETF rats were lower in the cornu ammonis area 2 at 8 weeks old and in the prelimbic and infralimbic cortices at both ages. No apoptotic cell death was detected in OLETF rats, but the percentage of neurons co-expressing activating transcription factor 4 and cholecystokinin and parvalbumin was higher in OLETF rats at both ages in the anterior cingulate cortex and basolateral amygdala, respectively. These results suggest that altered emotional behavior and related neurological changes in the corticolimbic system are already present in the prediabetic stage of OLETF rats.
Collapse
Affiliation(s)
- Ryosuke Ochi
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Naoto Fujita
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Natsuki Goto
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Kaho Takaishi
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Takaya Oshima
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Son Tien Nguyen
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
| | - Hisao Nishijo
- System Emotional Science, Faculty of Medicine, University of Toyama, Sugitani, Toyama, Japan
| | - Susumu Urakawa
- Department of Musculoskeletal Functional Research and Regeneration, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan
- * E-mail:
| |
Collapse
|
5
|
Takada Y, Hanaoka T, Imagita H, Yasui T, Takeshita D, Abe M, Kawata S, Yamakami T, Okada K, Washio H, Okuda S, Minematsu A, Nakamura T, Terada S, Yamada T, Nakatani A, Sakata S. Long-term wheel-running prevents reduction of grip strength in type 2 diabetic rats. Physiol Rep 2021; 9:e15046. [PMID: 34558206 PMCID: PMC8461031 DOI: 10.14814/phy2.15046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/27/2021] [Accepted: 08/31/2021] [Indexed: 11/29/2022] Open
Abstract
Diabetic skeletal muscles show reduced contractile force and increased fatigability. Hands are a target for several diabetes-induced complications. Therefore, reduced handgrip strength often occurs as a consequence of diabetes. The aim of this study was to examine whether long-term exercise can prevent reduction of grip strength in type 2 diabetes mellitus (T2DM) model OLETF rats, and to explore the mechanisms underlying diabetes-induced grip strength reduction. Ten 5-week-old OLETF rats were used as experimental animals, and five non-diabetic LETO rats as controls of OLETF rats. Half OLETF rats performed daily voluntary wheel-running for 17 months (OLETF + EXE), and the rest of OLETF and LETO rats were sedentary. Grip strength was higher in OLETF + EXE and LETO groups than in OLETF group. OLETF group with hyperglycemia showed an increase in HbA1c, serum TNF-α, and muscle SERCA activity, but a decrease in circulating insulin. Each fiber area, total fiber area, and % total fiber area in type IIb fibers of extensor digitorum longus muscles were larger in OLETF + EXE and LETO groups than in OLETF group. There was a positive correlation between grip strength and the above three parameters concerning type IIb fiber area. Therefore, type IIb fiber atrophy may be the major direct cause of grip strength reduction in OLETF group, although there seems multiple etiological mechanisms. Long-term wheel-running may have blocked the diabetes-induced reduction of grip strength by preventing type IIb fiber atrophy. Regular exercise may be a potent modality for preventing not only the progression of diabetes but muscle dysfunction in T2DM patients.
Collapse
Affiliation(s)
- Yoshihiro Takada
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
- Department of Human DevelopmentGraduate School of Human Development and EnvironmentKobe UniversityKobeJapan
| | - Tomoko Hanaoka
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Hidetaka Imagita
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Toshihide Yasui
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
- Department of Health and SportsMukogawa Women's UniversityNishinomiyaJapan
| | - Daisuke Takeshita
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Masami Abe
- Graduate School of Health SciencesSapporo Medical UniversitySapporoJapan
| | - Shinnosuke Kawata
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Taku Yamakami
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Keisuke Okada
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Hiroe Washio
- Department of NursingSchool of Health SciencesKansai University of International StudiesMikiJapan
| | - Syunji Okuda
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Akira Minematsu
- Division of Health ScienceGraduate School of Health ScienceKio UniversityNaraJapan
| | - Tomohiro Nakamura
- Division of Human SciencesFaculty of EngineeringOsaka Institute of TechnologyOsakaJapan
| | - Shin Terada
- Department of Life SciencesGraduate School of Arts and SciencesUniversity of TokyoTokyoJapan
| | - Takashi Yamada
- Graduate School of Health SciencesSapporo Medical UniversitySapporoJapan
| | - Akira Nakatani
- Laboratory of Exercise PhysiologyDepartment of Health and Sports Science EducationNara University of EducationNaraJapan
| | - Susumu Sakata
- Department of Physiology 1Nara Medical University School of MedicineKashiharaJapan
| |
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Claude Szpirer
- Université Libre de Bruxelles, B-6041, Gosselies, Belgium.
- , Waterloo, Belgium.
| |
Collapse
|
7
|
Wanezaki S, Saito S, Inoue N, Tachibana N, Shirouchi B, Sato M, Yanagita T, Nagao K. Soy β-Conglycinin Peptide Attenuates Obesity and Lipid Abnormalities in Obese Model OLETF Rats. J Oleo Sci 2020; 69:495-502. [PMID: 32378551 DOI: 10.5650/jos.ess20010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We previously reported that soy β-conglycinin (βCG) improves obesity-induced metabolic abnormalities, but not obesity, in obese model Otsuka Long-Evans Tokushima fatty (OLETF) rats. In the present study, we aimed to investigate the effects of βCG-derived peptide consumption on obesity and lipid abnormality in OLETF rats. To this end, wild-type Long-Evans Tokushima Otsuka and OLETF rats were provided a normal diet containing 20% casein for four weeks as a control. In addition, we prepared βCG peptide by enzymatic hydrolysis, and OLETF rats were fed a diet in which half of the casein was replaced by βCG peptide (βCG peptide group). Consequently, rats in the βCG peptide group showed decreased abdominal white adipose tissue weight and lipid content (serum and liver triglycerides, and serum and liver cholesterol) compared to control OLETF rats. Further analysis demonstrated that βCG peptide consumption decreased lipogenic enzyme activity and increased lipolytic enzyme activity in the liver of OLETF rats. In addition, suppressive effects on both synthesis and absorption of cholesterol were observed in βCG peptide-fed OLETF rats. These findings suggest that peptidization of βCG enhanced the anti-obese and hypolipidemic effects of βCG.
Collapse
Affiliation(s)
| | - Shintaro Saito
- Department of Biological Resource Science, Saga University
| | - Nao Inoue
- Faculty of Agriculture, Yamagata University
| | | | - Bungo Shirouchi
- Department of Bioscience and Biotechnology, Graduate School, Kyushu University
| | - Masao Sato
- Department of Bioscience and Biotechnology, Graduate School, Kyushu University
| | | | - Koji Nagao
- Department of Biological Resource Science, Saga University
| |
Collapse
|
8
|
Effects of Propolis Extract and Propolis-Derived Compounds on Obesity and Diabetes: Knowledge from Cellular and Animal Models. Molecules 2019; 24:molecules24234394. [PMID: 31805752 PMCID: PMC6930477 DOI: 10.3390/molecules24234394] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 12/23/2022] Open
Abstract
Propolis is a natural product resulting from the mixing of bee secretions with botanical exudates. Since propolis is rich in flavonoids and cinnamic acid derivatives, the application of propolis extracts has been tried in therapies against cancer, inflammation, and metabolic diseases. As metabolic diseases develop relatively slowly in patients, the therapeutic effects of propolis in humans should be evaluated over long periods of time. Moreover, several factors such as medical history, genetic inheritance, and living environment should be taken into consideration in human studies. Animal models, especially mice and rats, have some advantages, as genetic and microbiological variables can be controlled. On the other hand, cellular models allow the investigation of detailed molecular events evoked by propolis and derivative compounds. Taking advantage of animal and cellular models, accumulating evidence suggests that propolis extracts have therapeutic effects on obesity by controlling adipogenesis, adipokine secretion, food intake, and energy expenditure. Studies in animal and cellular models have also indicated that propolis modulates oxidative stress, the accumulation of advanced glycation end products (AGEs), and adipose tissue inflammation, all of which contribute to insulin resistance or defects in insulin secretion. Consequently, propolis treatment may mitigate diabetic complications such as nephropathy, retinopathy, foot ulcers, and non-alcoholic fatty liver disease. This review describes the beneficial effects of propolis on metabolic disorders.
Collapse
|
9
|
Zhang N, Zhang HY, Bi SA, Moran TH, Bi S. Differential regulation of thyrotropin-releasing hormone mRNA expression in the paraventricular nucleus and dorsomedial hypothalamus in OLETF rats. Neurosci Lett 2019; 703:79-85. [PMID: 30902570 DOI: 10.1016/j.neulet.2019.03.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/17/2019] [Accepted: 03/18/2019] [Indexed: 02/05/2023]
Abstract
Thyrotropin-releasing hormone (TRH) plays an important role in the regulation of energy balance. While the regulation of TRH in the paraventricular nucleus (PVN) in response to changes of energy balance has been well studied, how TRH is regulated in the dorsomedial hypothalamus (DMH) in maintaining energy homeostasis remains unclear. Here, we assessed the effects of food restriction and exercise on hypothalamic Trh expression using Otsuka Long-Evens Tokushima Fatty (OLETF) rats. Sedentary ad lib fed OLETF rats (OLETF-SED) became hyperphagic and obese. These alterations were prevented in OLETF rats with running wheel access (OLETF-RW) or food restriction in which their food was pair-fed (OLETF-PF) to the intake of lean control rats (LETO-SED). Evaluation of hypothalamic gene expression revealed that Trh mRNA expression was increased in the PVN of OLETF-SED rats and normalized in OLETF-RW and OLETF-PF rats compared to LETO-SED rats. In contrast, the expression of Trh in the DMH was decreased in OLETF-SED rats relative to LETO-SED rats. This alteration was reversed in OLETF-RW rats as seen in LETO-SED rats, but food restriction resulted in a significant increase in DMH Trh expression in OLETF-PF rats compared to LETO-SED rats. Strikingly, while Trh mRNA expression was decreased in the PVN of intact rats in response to acute food deprivation, food deprivation resulted in increased expression of Trh in the DMH. Together, these results demonstrate the differential regulation of Trh expression in the PVN and DMH in OLETF rats and suggest that DMH TRH also contributes to hypothalamic regulation of energy balance.
Collapse
Affiliation(s)
- Ni Zhang
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Psychiatry, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hai-Ying Zhang
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sophia A Bi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Timothy H Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sheng Bi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
10
|
Zhang N, Bi S. Effects of physical exercise on food intake and body weight: Role of dorsomedial hypothalamic signaling. Physiol Behav 2018; 192:59-63. [DOI: 10.1016/j.physbeh.2018.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/10/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022]
|
11
|
Shimada R, Fujita M, Yuasa M, Sawamura H, Watanabe T, Nakashima A, Suzuki K. Oral administration of green algae, Euglena gracilis, inhibits hyperglycemia in OLETF rats, a model of spontaneous type 2 diabetes. Food Funct 2018; 7:4655-4659. [PMID: 27775129 DOI: 10.1039/c6fo00606j] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the present study, the effects of Euglena and paramylon on hyperglycemia were examined in Otsuka Long-Evans Tokushima fatty (OLETF; type 2 diabetes mellitus model) rats. OLETF rats were fed an AIN-93 M diet containing cellulose, Euglena, or paramylon for 10 weeks. Long-Evans Tokushima Otsuka (LETO) rats were used as nondiabetic controls. An oral glucose-tolerance test (OGTT) was performed at 0 and 10 weeks. OLETF control rats were obese because of bulimia and showed abdominal fat accumulation and hyperglycemia. Euglena supplementation improved hyperglycemia and decreased food intake, body weight gain, and abdominal fat. However, there were no changes in the paramylon-supplemented group compared to the OLETF control group. Triglyceride concentrations in the serum and liver were lower in Euglena-supplemented rats than in OLETF control rats. There was a correlation between hepatic triglyceride concentration and the area under the curve (AUC) of OGTT at 10 weeks. This suggests that the improvement in glycemic control in the Euglena-supplemented group may depend on substances other than paramylon present in Euglena.
Collapse
Affiliation(s)
- Ryoko Shimada
- Department of Dietary Environment Analysis, School of Human Science and Environment, University of Hyogo, 1-1-12 Sinzaike Honcho, Himeji 670-0092, Japan. and Department of Health and Nutrition, Faculty of Health Science, Osaka Aoyama University, 2-11-1 Niina, Minoh, Osaka 562-8580, Japan
| | - Miho Fujita
- Department of Dietary Environment Analysis, School of Human Science and Environment, University of Hyogo, 1-1-12 Sinzaike Honcho, Himeji 670-0092, Japan.
| | - Masahiro Yuasa
- Department of Dietary Environment Analysis, School of Human Science and Environment, University of Hyogo, 1-1-12 Sinzaike Honcho, Himeji 670-0092, Japan. and Department of Nutrition Science, Faculty of Nursing and Nutrition, University of Nagasaki, 1-1-1 Manabino, Nagayo-cho, Nishi-Sonogi-gun, Nagasaki 851-2195, Japan
| | - Hiromi Sawamura
- Department of Molecular Nutrition, School of Human Science and Environment, University of Hyogo, 1-1-12 Sinzaike Honcho, Himeji 670-0092, Japan
| | - Toshiaki Watanabe
- Department of Dietary Environment Analysis, School of Human Science and Environment, University of Hyogo, 1-1-12 Sinzaike Honcho, Himeji 670-0092, Japan. and Department of Health and Nutrition, Faculty of Health Science, Osaka Aoyama University, 2-11-1 Niina, Minoh, Osaka 562-8580, Japan
| | - Ayaka Nakashima
- Euglena Co., Ltd., 5-33-1 Shiba, Minato-ku, Tokyo 108-0014, Japan
| | - Kengo Suzuki
- Euglena Co., Ltd., 5-33-1 Shiba, Minato-ku, Tokyo 108-0014, Japan
| |
Collapse
|
12
|
Kim YJ, Schroeder M, Liang NC, Moran TH, Weller A, Bi S. Effects of early postnatal environment on hypothalamic gene expression in OLETF rats. PLoS One 2017; 12:e0178428. [PMID: 28575002 PMCID: PMC5456065 DOI: 10.1371/journal.pone.0178428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/12/2017] [Indexed: 11/22/2022] Open
Abstract
Previous reports have shown that the early postnatal environment has the ability to modify the obesity phenotype of Otsuka Long-Evans Tokushima Fatty (OLETF) rats. To determine whether this early postnatal environment affects hypothalamic signaling systems involved in energy balance, OLETF pups and lean Long-Evans Tokushima Otsuka (LETO) pups were cross-fostered to same or opposite strain Dams (designated as LdLp: LETO pups with LETO dams; LdOp: OLETF pups with LETO dams; OdLp: LETO pups with OLETF dams; and OdOp: OLETF pups with OLETF dams). Hypothalamic gene expression was examined at postnatal day 23 (PND 23) and PND 90 as OdOp rats started to gain more body weight at PND 23 and developed obesity at PND 90 relative to lean control LdLp rats. On PND 23, neuropeptide Y (Npy) gene expression was significantly increased in the dorsomedial hypothalamus (DMH) in both LdOp and OdOp pups compared to LdLp pups. Maternal environment did not affect DMH Npy expression in LETO weanlings. On PND 90, maternal environment during the cross-fostering period had a major effect on DMH Npy expression. Levels were significantly increased in both OdOp and OdLp rats relative to those in LdOp rats and LdLp controls. Reduced expression of Npy in the DMH of LdOp rats was consistent with their reduction of body weight compared to OdOp rats. In contrast to DMH Npy, gene expression for Npy and proopiomelanocortin in the arcuate nucleus appeared to appropriately respond to alterations in body weight and plasma leptin levels. Levels of oxytocin gene expression in the paraventricular nucleus were lower in offspring raised by LETO dams apparently responding to the higher DMH NPY levels. Together, our results demonstrate effects of both genotype and early postnatal environment on obesity of OLETF rats and further suggest an important role of DMH NPY in the development of obesity of OLETF rats.
Collapse
Affiliation(s)
- Yonwook J. Kim
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Mariana Schroeder
- Psychology Department and Gonda Brain Research Center, Bar Ilan University, Ramat-Gan, Israel
| | - Nu-Chu Liang
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Timothy H. Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Aron Weller
- Psychology Department and Gonda Brain Research Center, Bar Ilan University, Ramat-Gan, Israel
| | - Sheng Bi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
13
|
Nagao K, Jinnouchi T, Kai S, Yanagita T. Pterostilbene, a dimethylated analog of resveratrol, promotes energy metabolism in obese rats. J Nutr Biochem 2017; 43:151-155. [PMID: 28319852 DOI: 10.1016/j.jnutbio.2017.02.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/29/2016] [Accepted: 02/08/2017] [Indexed: 11/27/2022]
Abstract
Pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene) is a dimethylated analog of resveratrol and has been reported to exert various pharmacological effects. In this study, we evaluated the effect of pterostilbene on the pathogenesis of obesity and energy metabolism in obese rats. Pterostilbene significantly activates silent mating type information regulation 2 homolog-1 and peroxisome proliferator-activated receptor-alpha in vitro. At 4 weeks a 0.5% pterostilbene diet markedly suppressed the abdominal white adipose tissue (WAT) accumulation in obese rats. The oxygen consumption and energy expenditure were significantly higher in the pterostilbene group, and pterostilbene increased the fat metabolism rather than the carbohydrate metabolism in obese rats. The mRNA level of uncoupling protein, a thermogenic regulator, was increased and the mRNA levels of fatty acid synthase and leptin, which are involved in lipogenesis and fat storage, were markedly decreased in WAT after the pterostilbene feeding. These results suggest that pterostilbene prevents WAT accumulation through the enhancement of energy metabolism and partly the suppression of lipogenesis in obese OLETF rats.
Collapse
Affiliation(s)
- Koji Nagao
- Department of Applied Biochemistry and Food Science, Saga University, Saga 840-8502, Japan; The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan.
| | - Tomoyuki Jinnouchi
- Department of Applied Biochemistry and Food Science, Saga University, Saga 840-8502, Japan
| | - Shunichi Kai
- Department of Applied Biochemistry and Food Science, Saga University, Saga 840-8502, Japan
| | - Teruyoshi Yanagita
- Department of Health and Nutrition Sciences, Nishikyushu University, Kanzaki 842-8585, Japan
| |
Collapse
|
14
|
Yoon S, Kim J, Lee H, Lee H, Lim J, Yang H, Shin SS, Yoon M. The effects of herbal composition Gambigyeongsinhwan (4) on hepatic steatosis and inflammation in Otsuka Long-Evans Tokushima fatty rats and HepG2 cells. JOURNAL OF ETHNOPHARMACOLOGY 2017; 195:204-213. [PMID: 27845265 DOI: 10.1016/j.jep.2016.11.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 10/06/2016] [Accepted: 11/04/2016] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Hepatic steatosis has risen rapidly in parallel with a dramatic increase in obesity. The aim of this study was to determine whether the herbal composition Gambigyeongsinhwan (4) (GGH(4)), composed of Curcuma longa L. (Zingiberaceae), Alnus japonica (Thunb.) Steud. (Betulaceae), and the fermented traditional Korean medicine Massa Medicata Fermentata, regulates hepatic steatosis and inflammation. MATERIALS AND METHODS The effects of GGH(4) on hepatic steatosis and inflammation in Otsuka Long-Evans Tokushima fatty (OLETF) rats and HepG2 cells were examined using Oil red O, hematoxylin and eosin, and toluidine blue staining, immunohistochemistry, quantitative real-time polymerase chain reaction, and peroxisome proliferator-activated receptor α (PPARα) transactivation assay. RESULTS Administration of GGH(4) to OLETF rats improved hepatic steatosis and lowered serum levels of alanine transaminase, total cholesterol, triglycerides, and free fatty acids. GGH(4) increased mRNA levels of fatty acid oxidation enzymes (ACOX, HD, CPT-1, and MCAD) and decreased mRNA levels of lipogenesis genes (FAS, ACC1, C/EBPα, and SREBP-1c) in the liver of OLETF rats. In addition, infiltration of inflammatory cells and expression of inflammatory cytokines (CD68, TNFα, and MCP-1) in liver tissue were reduced by GGH(4). Treatment of HepG2 cells with a mixture of oleic acid and palmitoleic acid induced significant lipid accumulation, but GGH(4) inhibited lipid accumulation by regulating the expression of hepatic fatty acid oxidation and lipogenic genes. GGH(4) also increased PPARα reporter gene expression. These effects of GGH(4) were similar to those of the PPARα activator fenofibrate, whereas the PPARα antagonist GW6471 reversed the inhibitory effects of GGH(4) on lipid accumulation in HepG2 cells. CONCLUSIONS These results suggest that GGH(4) inhibits obesity-induced hepatic steatosis and that this process may be mediated by regulation of the expression of PPARα target genes and lipogenic genes. GGH(4) also suppressed obesity-related hepatic inflammation. Thus, GGH(4) may be a promising drug for the treatment of obesity-related liver diseases.
Collapse
Affiliation(s)
- Seolah Yoon
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea
| | - Jeongjun Kim
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea
| | - Hyunghee Lee
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea
| | - Haerim Lee
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea
| | - Jonghoon Lim
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea
| | - Heejeong Yang
- Laboratory of Natural Products Chemistry, College of Pharmacy, Kangwon National University, Chuncheon 24341, Korea
| | - Soon Shik Shin
- Formula Sciences, College of Oriental Medicine, Dongeui University, Busan 47340, Korea.
| | - Michung Yoon
- Department of Biomedical Engineering, Mokwon University, Daejeon 35349, Korea.
| |
Collapse
|
15
|
Abstract
Multiple physiologic and neural systems contribute to the controls over what and how much we eat. These systems include signaling involved in the detection and signaling of nutrient availability, signals arising from consumed nutrients that provide feedback information during a meal to induce satiation, and signals related to the rewarding properties of eating. Each of these has a separate neural representation, but important interactions among these systems are critical to the overall controls of food intake.
Collapse
Affiliation(s)
- Timothy H Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA; Global Obesity Prevention Center at Johns Hopkins, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Ellen E Ladenheim
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA
| |
Collapse
|
16
|
Gumbs MC, van den Heuvel JK, la Fleur SE. The effect of obesogenic diets on brain Neuropeptide Y. Physiol Behav 2016; 162:161-73. [DOI: 10.1016/j.physbeh.2016.04.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/18/2016] [Accepted: 04/26/2016] [Indexed: 12/18/2022]
|
17
|
Central transthyretin acts to decrease food intake and body weight. Sci Rep 2016; 6:24238. [PMID: 27053000 PMCID: PMC4823743 DOI: 10.1038/srep24238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/22/2016] [Indexed: 01/09/2023] Open
Abstract
Transthyretin (TTR) is a blood and cerebrospinal fluid transporter of thyroxine and retinol. Gene expression profiling revealed an elevation of Ttr expression in the dorsomedial hypothalamus (DMH) of rats with exercise-induced anorexia, implying that central TTR may also play a functional role in modulating food intake and energy balance. To test this hypothesis, we have examined the effects of brain TTR on food intake and body weight and have further determined hypothalamic signaling that may underlie its feeding effect in rats. We found that intracerebroventricular (icv) administration of TTR in normal growing rats decreased food intake and body weight. This effect was not due to sickness as icv TTR did not cause a conditioned taste aversion. ICV TTR decreased neuropeptide Y (NPY) levels in the DMH and the paraventricular nucleus (P < 0.05). Chronic icv infusion of TTR in Otsuka Long-Evans Tokushima Fatty rats reversed hyperphagia and obesity and reduced DMH NPY levels. Overall, these results demonstrate a previously unknown anorectic action of central TTR in the control of energy balance, providing a potential novel target for treating obesity and its comorbidities.
Collapse
|
18
|
Lee SK, Kwon OJ, Jeon HM, Kim SJ. Long-term effects of duodenojejunal bypass on diabetes in Otsuka Long-Evans Tokushima Fatty rats. Asian J Surg 2016; 40:262-269. [PMID: 26787497 DOI: 10.1016/j.asjsur.2015.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/20/2015] [Accepted: 11/16/2015] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Previous studies have shown that duodenojejunal bypass (DJB) resolves type 2 diabetes. However, this finding has been contradicted by several experimental and human trials and therefore needs to be clarified. METHODS Otsuka Long-Evans Tokushima Fatty (OLETF) rats randomly underwent a sham operation or DJB. Thereafter, we measured daily body weight, serum levels of glucose and gut hormones such as glucagon-like peptide-1, insulin, and leptin. RESULTS There was no significant difference in weight loss between rats in the DJB and sham-operated groups. There were also no differences in the area under the curve of glucose tolerance between the DJB and sham-operated groups (32466 ± 2261 mg/dL·min vs. 26319 ± 427 mg/dL·min; p = 0.35). Duodenojejunal bypass did not affect plasma concentrations of various gut hormones such as glucagon-like peptide-1, insulin, and leptin. CONCLUSIONS We have shown that DJB alone does not improve glucose tolerance in obese, diabetic OLETF rats. Therefore, it may be that DJB alone is insufficient for diabetic control in obese diabetic rats. The addition of a restrictive component such as sleeve gastrectomy, or a new drug may be necessary for achieving diabetes reversal.
Collapse
Affiliation(s)
- Sang Kuon Lee
- Department of Surgery, Daejeon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Daejeon, Republic of Korea
| | - Oh-Joo Kwon
- Department of Biochemistry, College of Medicine, Catholic University of Korea, Seoul, Republic of Korea
| | - Hae Myung Jeon
- Department of Surgery, Uijeongbu St. Mary's Hospital, College of Medicine, Catholic University of Korea, Uijeongbu, Republic of Korea
| | - Say-June Kim
- Department of Surgery, Daejeon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Daejeon, Republic of Korea.
| |
Collapse
|
19
|
Ning SL, Zheng WS, Su J, Liang N, Li H, Zhang DL, Liu CH, Dong JH, Zhang ZK, Cui M, Hu QX, Chen CC, Liu CH, Wang C, Pang Q, Chen YX, Yu X, Sun JP. Different downstream signalling of CCK1 receptors regulates distinct functions of CCK in pancreatic beta cells. Br J Pharmacol 2015; 172:5050-67. [PMID: 26248680 DOI: 10.1111/bph.13271] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 07/18/2015] [Accepted: 07/26/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. EXPERIMENTAL APPROACH Apoptosis in pancreatic beta cell apoptosis was evaluated using Hoechst-33342 staining, TUNEL assays and Annexin-V-FITC/PI staining. Insulin secretion and second messenger production were monitored using ELISAs. Protein and phospho-protein levels were determined by Western blotting. A glucose tolerance test was carried out to examine the functions of CCK-8s in streptozotocin-induced diabetic mice. KEY RESULTS The sulfated carboxy-terminal octapeptide CCK26-33 amide (CCK-8s) activated CCK1 receptors and induced accumulation of both IP3 and cAMP. Whereas Gq -PLC-IP3 signalling was required for the CCK-8s-induced insulin secretion under low-glucose conditions, Gs -PKA/Epac signalling contributed more strongly to the CCK-8s-mediated insulin secretion in high-glucose conditions. CCK-8s also promoted formation of the CCK1 receptor/β-arrestin-1 complex in pancreatic beta cells. Using β-arrestin-1 knockout mice, we demonstrated that β-arrestin-1 is a key mediator of both CCK-8s-mediated insulin secretion and of its the protective effect against apoptosis in pancreatic beta cells. The anti-apoptotic effects of β-arrestin-1 occurred through cytoplasmic late-phase ERK activation, which activates the 90-kDa ribosomal S6 kinase-phospho-Bcl-2-family protein pathway. CONCLUSIONS AND IMPLICATIONS Knowledge of different CCK1 receptor-activated downstream signalling pathways in the regulation of distinct functions of pancreatic beta cells could be used to identify biased CCK1 receptor ligands for the development of new anti-diabetic drugs.
Collapse
Affiliation(s)
- Shang-lei Ning
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Qilu Hospital, Shandong University, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Wen-shuai Zheng
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jing Su
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Nan Liang
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Hui Li
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Dao-lai Zhang
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China
| | - Chun-hua Liu
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jun-hong Dong
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Zheng-kui Zhang
- Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Min Cui
- Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Qiao-Xia Hu
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Chao-chao Chen
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Chang-hong Liu
- Shandong Provincial Qianfoshan, Shandong University, Jinan, Shandong, China
| | - Chuan Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Qi Pang
- Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| | - Yu-xin Chen
- Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Xiao Yu
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Qilu Hospital, Shandong University, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jin-peng Sun
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China.,Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| |
Collapse
|
20
|
Fujitani M, Mizushige T, Bhattarai K, Iwahara A, Aida R, Kishida T. The daidzein- and estradiol- induced anorectic action in CCK or leptin receptor deficiency rats. Biosci Biotechnol Biochem 2015; 79:1164-71. [DOI: 10.1080/09168451.2015.1018123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
We investigated the effect of daidzein feeding and estradiol treatment on food intake in cholecystokinin-1 receptor (CCK1R) deficiency, leptin receptor (ObRb) deficiency rats and their wild-type rats. These rats underwent an ovariectomy or a sham operation. For the 5 week experiment, each rat was divided in three groups: control, daidzein (150 mg/kg diet), and estradiol (4.2 μg/rat/day) groups. In both CCK1R+ and CCK1R− rats, daidzein feeding and estradiol treatment significantly decreased food intake. Daidzein feeding significantly reduced food intake in ovariectomized ObRb− rats, although not in ObRb+ rats. Estradiol treatment significantly lowered food intake in ovariectomized ObRb+ and ObRb− rats. In the ovariectomized rats, estradiol treatment significantly increases uterine weight, while daidzein feeding did not change it, suggesting that daidzein might have no or weak estrogenic effect in our experiment. These results suggest that CCK1R and ObRb signalings were not essential for the daidzein- and estradiol-induced anorectic action.
Collapse
Affiliation(s)
- Mina Fujitani
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
| | - Takafumi Mizushige
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
- Faculty of Agriculture, Department of Applied Biological Chemistry, Utsunomiya University, 350 Minemachi, Utsunomiya Tochigi 321–8505, Japan
| | - Keshab Bhattarai
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
| | - Asami Iwahara
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
| | - Ryojiro Aida
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
| | - Taro Kishida
- Laboratory of Nutrition Science, Faculty of Agriculture, Department of Biological Resources, Ehime University, Matsuyama, Japan
| |
Collapse
|
21
|
Moon KY, Park MK, Leikauf GD, Park CS, Jang AS. Diesel exhaust particle-induced airway responses are augmented in obese rats. Int J Toxicol 2014; 33:21-8. [PMID: 24536021 DOI: 10.1177/1091581813518355] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Air pollutants and obesity are important factors that contribute to asthma. The aim of this study was to assess the airway responsiveness and inflammation in Otsuka-Long Evans Tokushima Fatty (OLETF) obese rats and Long Evans Tokushima-Otsuka (LETO) nonobese rats exposed to diesel exhaust particles (DEPs). Otsuka Long Evans Tokushima fatty rats and LETO rats were exposed intranasally to DEP and then challenged with aerosolized DEP on days 6 to 8. Body plethysmography, bronchoalveolar lavage (BAL), and histology were performed. Enhanced pause (Penh) was measured as an indicator of airway resistance on day 9 and samples were collected on day 10. After exposure to DEP, the OLETF group exhibited a greater increase in Penh compared to that in the LETO group. Moreover, the BAL fluid in mice showed an increase in the total and differential cell counts in the DEP-exposed OLETF group compared to that in the DEP-exposed LETO group. Histological assessment of lung tissue from each group revealed that the DEP-exposed OLETF group tended to have increased inflammatory cell infiltrations in the prebronchial area. Increased peroxisome proliferator-activated receptor γ, coactivator 1β messenger RNA was observed in the lungs of obese rats compared to that in nonobese rats following DEP exposure. These data indicate that the DEP-exposed OLETF group had increased airway responses and inflammation compared to the DEP-exposed LETO group, indicating that diesel particulates and obesity may be co-contributors to asthma.
Collapse
Affiliation(s)
- Kuk-Young Moon
- Department of Internal Medicine, Division of Allergy and Respiratory Diseases, Soonchunhyang University Hospital, 170 Jomaru-ro, Wonmi-gu, Bucheon, Gyeonggi-Do, 420-767, Republic of Korea.
| | | | | | | | | |
Collapse
|
22
|
Effect ofVaccinium ashei readeLeaves on Lipid Metabolism in Otsuka Long-Evans Tokushima Fatty Rats. Biosci Biotechnol Biochem 2014; 72:1619-22. [DOI: 10.1271/bbb.80036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
23
|
Myer JR, Romach EH, Elangbam CS. Species- and Dose-Specific Pancreatic Responses and Progression in Single- and Repeat-Dose Studies with GI181771X. Toxicol Pathol 2013; 42:260-74. [DOI: 10.1177/0192623313506792] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Compound-induced pancreatic injury is a serious liability in preclinical toxicity studies. However, its relevance to humans should be cautiously evaluated because of interspecies variations. To highlight such variations, we evaluated the species- and dose-specific pancreatic responses and progression caused by GI181771X, a novel cholecystokinin 1 receptor agonist investigated by GlaxoSmithKline for the treatment of obesity. Acute (up to 2,000 mg/kg GI181771X, as single dose) and repeat-dose studies in mice and/or rats (0.25–250 mg/kg/day for 7 days to 26 weeks) showed wide-ranging morphological changes in the pancreas that were dose and duration dependent, including necrotizing pancreatitis, acinar cell hypertrophy/atrophy, zymogen degranulation, focal acinar cell hyperplasia, and interstitial inflammation. In contrast to rodents, pancreatic changes were not observed in cynomolgus monkeys given GI181771X (1–500 mg/kg/day with higher systemic exposure than rats) for up to 52 weeks. Similarly, no GI181771X treatment-associated abnormalities in pancreatic structure were noted in a 24-week clinical trial with obese patients (body mass index >30 or >27 kg/m2) as assessed by abdominal ultrasound or by magnetic resonance imaging. Mechanisms for interspecies variations in the pancreatic response to CCK among rodents, monkeys, and humans and their relevance to human risk are discussed.
Collapse
Affiliation(s)
- James R. Myer
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Elizabeth H. Romach
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | | |
Collapse
|
24
|
Hegedűs C, Kovács D, Drimba L, Sári R, Varga A, Németh J, Szilvássy Z, Peitl B. Investigation of the metabolic effects of chronic clozapine treatment on CCK-1 receptor deficient Otsuka Long Evans Tokushima Fatty (OLETF) rats. Eur J Pharmacol 2013; 718:188-96. [DOI: 10.1016/j.ejphar.2013.08.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 08/19/2013] [Accepted: 08/30/2013] [Indexed: 12/15/2022]
|
25
|
Asarian L, Geary N. Sex differences in the physiology of eating. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1215-67. [PMID: 23904103 DOI: 10.1152/ajpregu.00446.2012] [Citation(s) in RCA: 346] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating.
Collapse
Affiliation(s)
- Lori Asarian
- Institute of Veterinary Physiology and Center for Integrated Human Physiology, University of Zurich, Zurich, Switzerland; and
| | | |
Collapse
|
26
|
Time course of the development of nonalcoholic Fatty liver disease in the Otsuka long-evans Tokushima Fatty rat. Gastroenterol Res Pract 2013; 2013:342648. [PMID: 23737763 PMCID: PMC3666266 DOI: 10.1155/2013/342648] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/28/2013] [Accepted: 04/17/2013] [Indexed: 02/07/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is considered a hepatic manifestation of metabolic syndrome. In this study, we investigated histological and biochemical changes in NAFLD and the gene expression involving de novo lipogenesis in Otsuka Long-Evans Tokushima fatty (OLETF) rats. We used OLETF rats and Long-Evans Tokushima Otsuka (LETO) rats as animal models of NAFLD and as controls, respectively. Consistent observations were made at 4-week intervals up to 50 weeks of age, and all rats were fed ad libitum with standard food. Biochemical and histological changes were observed, and gene expression involved in de novo lipogenesis was measured using real-time polymerase chain reactions. As a results hepatic micro- and macrovesicular steatosis and hepatocyte ballooning were evident in the OLETF rats at 22-38 weeks of age but disappeared after 42 weeks; no fibrosis or collagen deposition was observed. Gene expression involved in de novo lipogenesis followed a pattern similar to that of the histological changes. In conclusion, in the absence of dietary manipulation, hepatic steatosis in OLETF rats is evident at 22-38 weeks and declines after 42 weeks. Therefore, OLETF rats at 22-38 weeks are recommended as animal models of hepatic steatosis.
Collapse
|
27
|
Cocaine- and amphetamine-regulated transcript (CART) peptide immunoreactivity in feeding- and reward-related brain areas of young OLETF rats. J Chem Neuroanat 2013; 50-51:75-84. [PMID: 23545074 DOI: 10.1016/j.jchemneu.2013.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/21/2013] [Accepted: 03/21/2013] [Indexed: 02/06/2023]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) peptide is expressed in brain areas involved in the control of appetite, drug reward and homeostatic regulation and it has an overall anorexigenic effect. Recently, we have shown that CART peptide immunoreactivity was significantly reduced in the rostral part of the nucleus accumbens and in the rostro-medial part of the nucleus of the solitary tract in adult CCK-1 receptor deficient obese diabetic Otsuka Long Evans Tokushima Fatty (OLETF) rats compared to Long Evans Tokushima Otsuka (LETO) lean controls. It is not clear, however, whether altered CART expression is caused primarily by the deficiency in CCK-1 signaling or whether is related to the obese and diabetic phenotype of the OLETF strain which develops at a later age. Therefore, in the present study, CART-immunoreaction in feeding-related areas of the brain was compared in young, age-matched (6-7 weeks old) non-obese, non-diabetic OLETF rats and in LETO controls. We found that, young, non-diabetic OLETF rats revealed unaltered distribution of CART-peptide expressing neurons and axons throughout the brain when compared to age-matched LETO rats. In contrast to previous results observed in the obese diabetic adult rats, intensity of CART immunoreaction did not differ in the areas related to control of food-intake and reward in the young OLETFs compared to young LETO rats. Our findings suggest that factors secondary to obesity and/or diabetes rather than impaired CCK-1 receptor signaling may contribute to altered CART expression in the OLETF strain.
Collapse
|
28
|
Panetta R, Meury L, Cao CQ, Puma C, Mennicken F, Cassar PA, Laird J, Groblewski T. Functional genomics of the rat neuromedin U receptor 1 reveals a naturally occurring deleterious allele. Physiol Genomics 2013; 45:89-97. [DOI: 10.1152/physiolgenomics.00070.2012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Neuromedin U (NMU) plays an important role in a number of physiological processes, but the relative contribution of its two known receptors, NMUR1 and NMUR2, is still poorly understood. Here we report the existence of a SNP T1022→A (Val341→Glu) in the third exon of the rat Nmur1 gene that leads to an inactive receptor. This SNP is present within the coding region of the highly conserved NPXXY motif found within all class A type G protein-coupled receptors and translates to an NMUR1 receptor that is not expressed on the cell surface. Genetic analysis of the Nmur1 gene in a population of Sprague-Dawley rats revealed that this strain is highly heterogeneous for the inactivating polymorphism. The loss of functional NMUR1 receptors in Sprague-Dawley rats homozygous for the inactive allele was confirmed by radioligand binding studies on native tissue expressing NMUR1. The physiological relevance of this functional genomics finding was examined in two nociceptive response models. The pronociceptive effects of NMU were abolished in rats lacking functional NMUR1 receptors. The existence of naturally occurring NMUR1-deficient rats provides a novel and powerful tool to investigate the physiological role of NMU and its receptors. Furthermore, it highlights the importance of verifying the NMUR1 single nucleotide polymorphism status for rats used in physiological, pharmacological or toxicological studies conducted with NMUR1 modulators.
Collapse
Affiliation(s)
- Rosemarie Panetta
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Luc Meury
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Chang Qing Cao
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Carole Puma
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Françoise Mennicken
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Paul A. Cassar
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| | - Jennifer Laird
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
- Department of Pharmacology & Experimental Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada
| | - Thierry Groblewski
- AstraZeneca Research and Development, CNS & Pain Innovative Medicines Science Unit, Montreal (Ville Saint-Laurent), Quebec, Canada; and
| |
Collapse
|
29
|
Ozaki T, Mohammad S, Morioka E, Takiguchi S, Ikeda M. Infant satiety depends on transient expression of cholecystokinin-1 receptors on ependymal cells lining the third ventricle in mice. J Physiol 2012; 591:1295-312. [PMID: 23266937 DOI: 10.1113/jphysiol.2012.247676] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Cholecystokinin (CCK) is a hypothetical controller for suckling and infancy body weight, although the underlying mechanisms remain unclear. Therefore, the present study analysed the mechanisms using mice lacking the CCK-1 receptor (CCK1R-/-). Although CCK1R-/- mice displayed normal weights at birth and adulthood, CCK1R-/- pups had enlarged adipocytes and were overweight from the first to second week after birth, regardless of maternal genotype. The lacZ reporter gene assay and/or calcium imaging analysis demonstrated that CCK-1 receptors were abundant in satiety-controlling regions such as the hypothalamus, brainstem, nodose ganglion and pylorus in adults, whereas these signals were few to lacking at pre-weanling stages. At postnatal day (PD) 6, the increase in cFos expression in the medullary nucleus tractus solitarius was similarly triggered by gastrointestinal milk- or saline filling in both genotypes, further indicating immature CCK-1 receptor function in an ascending satiety-controlling system during infancy. Conversely, third ventricle ependymal tanycyte-like cells expressed CCK-1 receptors with expression peaking at PD6. At PD6, wild-type but not CCK1R-/- mice had increased cFos immunoreactivity in ependymal cells following gastrointestinal milk filling whereas the response became negligible at PD12. In addition, ependymal cFos was not increased by saline filling, indicating that these responses are dependent on CCK-1 receptors, developmental stage and nutrients. Furthermore, body weights of wild-type pups were transiently increased by blocking ependymal CCK receptor function with microinjection of a CCK-1 antagonist, but not a CCK-2 antagonist. Hence, we demonstrate de novo functions of ependymal CCK-1 receptors and reveal a new aspect of infant satiety-controlling mechanisms.
Collapse
Affiliation(s)
- Tomoya Ozaki
- 1Graduate School of Innovative Life Science, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | | | | | | | | |
Collapse
|
30
|
Bi S, Kim YJ, Zheng F. Dorsomedial hypothalamic NPY and energy balance control. Neuropeptides 2012; 46:309-14. [PMID: 23083763 PMCID: PMC3508095 DOI: 10.1016/j.npep.2012.09.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/04/2012] [Accepted: 09/11/2012] [Indexed: 12/15/2022]
Abstract
Neuropeptide Y (NPY) is a potent hypothalamic orexigenic peptide. Within the hypothalamus, Npy is primarily expressed in the arcuate nucleus (ARC) and the dorsomedial hypothalamus (DMH). While the actions of ARC NPY in energy balance control have been well studied, a role for DMH NPY is still being unraveled. In contrast to ARC NPY that serves as one of downstream mediators of actions of leptin in maintaining energy homeostasis, DMH NPY is not under the control of leptin. Npy gene expression in the DMH is regulated by brain cholecystokinin (CCK) and other yet to be identified molecules. The findings of DMH NPY overexpression or induction in animals with increased energy demands and in certain rodent models of obesity implicate a role for DMH NPY in maintaining energy homeostasis. In support of this view, adeno-associated virus (AAV)-mediated overexpression of NPY in the DMH causes increases in food intake and body weight and exacerbates high-fat diet-induced hyperphagia and obesity. Knockdown of NPY in the DMH via AAV-mediated RNAi ameliorates hyperphagia, obesity and glucose intolerance of Otsuka Long-Evans Tokushima Fatty rats in which DMH NPY overexpression has been proposed to play a causal role. NPY knockdown in the DMH also prevents high-fat diet-induced hyperphagia, obesity and impaired glucose homeostasis. A detailed examination of actions of DMH NPY reveals that DMH NPY specifically affects nocturnal meal size and produces an inhibitory action on within meal satiety signals. In addition, DMH NPY modulates energy expenditure likely through affecting brown adipocyte formation and thermogenic activity. Overall, the recent findings provide clear evidence demonstrating critical roles for DMH NPY in energy balance control, and also imply a potential role for DMH NPY in maintaining glucose homeostasis.
Collapse
Affiliation(s)
- Sheng Bi
- Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | | | | |
Collapse
|
31
|
Fellmann L, Nascimento AR, Tibiriça E, Bousquet P. Murine models for pharmacological studies of the metabolic syndrome. Pharmacol Ther 2012. [PMID: 23178510 DOI: 10.1016/j.pharmthera.2012.11.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Metabolic syndrome has been described as the association of insulin resistance, hypertension, hyperlipidemia and obesity. Its prevalence increased dramatically, mainly in developed countries. Animal models are essential to understand the pathophysiology of this syndrome. This review presents the murine models of metabolic syndrome the most often used in pharmacological studies. The most common metabolic syndrome models exhibit a non-functional leptin pathway, or metabolic disorders induced by high fat diets. In a first part, and after a short introduction on leptin, its receptor and mechanism of action, we provide a detailed description of each model: SHROB, SHHF, JCR:LA-cp, Zucker, ZDF, Wistar Ottawa Karlsburg W, and Otsuka Long-Evans Tokushima Fatty rats, ob/ob, db/db, agouti yellow and Mc4R KO mice. The second part of this review is dedicated to metabolic syndrome models obtained by high fat feeding.
Collapse
Affiliation(s)
- Lyne Fellmann
- Laboratory of Neurobiology and Cardiovascular Pharmacology, EA4438, Faculty of Medicine, University of Strasbourg, France
| | | | | | | |
Collapse
|
32
|
Mohammad S, Ozaki T, Takeuchi K, Unno K, Yamoto K, Morioka E, Takiguchi S, Ikeda M. Functional compensation between cholecystokinin-1 and -2 receptors in murine paraventricular nucleus neurons. J Biol Chem 2012; 287:39391-401. [PMID: 23038256 PMCID: PMC3501058 DOI: 10.1074/jbc.m112.416214] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/02/2012] [Indexed: 01/11/2023] Open
Abstract
Cholecystokinin (CCK) and its receptor subtypes CCK-1 and -2 have diverse homeostatic functions. CCK-1 and -2 receptors share a common phosphatidylinositol signaling pathway, yet little is known regarding their possible functional coupling. We focused on CCK-mediated Ca(2+) signaling in parvocellular paraventricular nucleus (PVN) cells, which control satiety and other autonomic functions. Analysis of mouse hypothalamic slices demonstrated that the general CCK receptor agonist CCK-8s (10 nM) triggered Ca(2+) transients most significantly in the posterior subregion of the PVN (PaPo). This 10 nM CCK-8s-induced response was absent in CCK-1 receptor knock-out (CCK1R(-/-)) slices, showing that the response is mediated by CCK-1 receptors. CCK-8s concentrations higher than 30 nM triggered a Ca(2+) rise similarly in wild-type and CCK1R(-/-) slices. The large CCK-8s (100 nM)-induced Ca(2+) responses in CCK1R(-/-) slices were blocked by a CCK-2 receptor antagonist (CI-988), whereas those in wild-type slices required a mixture of CI-988 and lorglumide (a CCK-1 receptor antagonist) for complete antagonism. Therefore, CCK-1 and -2 receptors may function synergistically in single PaPo neurons and deletion of CCK-1 receptors may facilitate CCK-2 receptor signaling. This hypothesis was supported by results of real-time RT-PCR, immunofluorescence double labeling and Western blotting assays, which indicated CCK-2 receptor overexpression in PaPo neurons of CCK1R(-/-) mice. Furthermore, behavioral studies showed that intraperitoneal injections of lorglumide up-regulated food accesses in wild-type but not in CCK1R(-/-) mice, whereas CI-988 injections up-regulated food accesses in CCK1R(-/-) but not in wild-type mice. Compensatory CCK signaling via CCK-2 receptors in CCK1R(-/-) mice shed light on currently controversial satiety-controlling mechanisms.
Collapse
Affiliation(s)
| | - Tomoya Ozaki
- From the Graduate School of Innovative Life Science and
| | - Kouhei Takeuchi
- the Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama-city, Toyama 930-8555 and
| | - Katsuya Unno
- the Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama-city, Toyama 930-8555 and
| | - Kurumi Yamoto
- the Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama-city, Toyama 930-8555 and
| | - Eri Morioka
- From the Graduate School of Innovative Life Science and
| | - Soichi Takiguchi
- the Institute for Clinical Research, National Kyushu Cancer Center, 3-1-1 Notame, Minami-ku, Fukuoka 811-1395, Japan
| | - Masayuki Ikeda
- From the Graduate School of Innovative Life Science and
- the Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama-city, Toyama 930-8555 and
| |
Collapse
|
33
|
Genetic dissection of complex genetic factor involved in NIDDM of OLETF rat. EXPERIMENTAL DIABETES RESEARCH 2012; 2012:582546. [PMID: 23118743 PMCID: PMC3478749 DOI: 10.1155/2012/582546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 09/20/2012] [Indexed: 11/17/2022]
Abstract
The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type, noninsulin-dependent diabetes mellitus (NIDDM) in humans. NIDDM in this rat model was shown to be regulated by multiple genes. We have identified 14 quantitative trait loci (QTLs) responsible for NIDDM (Nidd1-14/of) on chromosomes 1, 5, 7, 8, 9, 11, 12, 14, 16, and 17 by a whole genome search in 160 F2 progenies obtained by mating the OLETF and the F344 rats. Among these loci, two QTLs, Nidd1 and 2/of, were declared significant loci at a genome-wide level. Nidd3, 8, 9, and 13/of exhibited heterosis: heterozygotes showing significantly higher glucose levels than OLETF or F344 homozygotes. We also found evidence for interaction (epistasis) between Nidd1/of and Nidd2/of, between Nidd1/of and Nidd10/of, between Nidd2/of and Nidd8/of, and between Nidd2/of and Nidd14/of. Furthermore, Nidd6 and 11/of showed linkage with body weight, and Nidd1, 2, 8, 9, 10, and 12/of had an interaction with body weight. These indicated that NIDDM in the OLETF would have a higher degree of genetic complexity. We suggest several interesting candidate genes located in rat genomic regions for Nidd1-14/of or the syntenic regions in human genome.
Collapse
|
34
|
Yuan Q, Fontenele-Neto JD, Fricker LD. Effect of Voluntary Exercise on Genetically ObeseCpefat/fatMice: Quantitative Proteomics of Serum. ACTA ACUST UNITED AC 2012; 12:1179-88. [PMID: 15292483 DOI: 10.1038/oby.2004.147] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To compare the effect of voluntary exercise on body weight, food consumption, and levels of serum proteins between wild-type and carboxypeptidase E-deficient (Cpefat/fat) mice. RESEARCH METHODS AND PROCEDURES Study 1 consisted of three groups of female mice: Cpefat/fat mice with continuous access to exercise wheels for 3 weeks (n = 4); wild-type C57BKS mice with access to exercise wheels for 3 weeks (n = 4); and sedentary Cpefat/fat mice (n = 3). Activity, body weight, and food consumption were monitored for this period and a subsequent 9-week period without exercise wheels. Study 2 consisted of four groups of male mice (n = 6 to 7 each): Cpefat/fat mice with exercise wheels, wild-type mice with exercise wheels, and Cpefat/fat and wild-type mice without exercise wheels. Body weight and food consumption were measured over 4 weeks. Sera were collected, and the protein profile was determined by 2-dimensional gel electrophoresis and mass spectrometry. RESULTS Cpefat/fat mice were moderately hyperphagic but lost weight during the initial exercise period because of greater energy expenditure. The effect of exercise was temporary, and the mice gained weight after the second week. Several serum proteins were found to be altered by exercise: haptoglobin was decreased by exercise in Cpefat/fat mice, and several kallikreins were increased by exercise in wild-type mice. DISCUSSION The access to exercise wheels provided an initial weight loss in Cpefat/fat mice, but this effect was offset by elevated food consumption. The serum proteomics results indicated that Cpefat/fat and wild-type mice differed in their response to exercise.
Collapse
Affiliation(s)
- Quan Yuan
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | | | |
Collapse
|
35
|
Duca FA, Swartz TD, Sakar Y, Covasa M. Decreased intestinal nutrient response in diet-induced obese rats: role of gut peptides and nutrient receptors. Int J Obes (Lond) 2012; 37:375-81. [PMID: 22546775 DOI: 10.1038/ijo.2012.45] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIMS Diet-induced obesity (DIO) is an excellent model for examining human obesity comprising both genotypic and environmental (diet) factors. Decreased responsiveness to peripheral satiety signaling may be responsible for the hyperphagia in this model. In this study, we investigated responses to nutrient-induced satiation in outbred DIO and DIO-resistant (DR) rats fed a high-energy/high-fat (HE/HF) diet as well as intestinal satiety peptide content, intestinal nutrient-responsive receptor abundance and vagal anorectic receptor expression. METHODS Outbred DIO and DR rats fed a HE/HF diet were tested for short-term feeding responses following nutrient (glucose and intralipid (IL)) gastric loads. Gene and protein expressions of intestinal satiety peptides and fatty acid-responsive receptors were examined from isolated proximal intestinal epithelial cells and cholecystokinin-1 receptor (CCK-1R) and leptin receptor (LepR) mRNA from the nodose ganglia of DIO and DR animals. RESULTS DIO rats were less responsive to IL- (P<0.05) but not glucose-induced suppression of food intake compared with DR rats. DIO rats exhibited decreased CCK, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1; P<0.05 for each) protein expression compared with DR rats. Also, DIO rats expressed more G-protein-coupled receptor 40 (GPR40; P<0.0001), GPR41 (P<0.001) and GPR120 (P<0.01) relative to DR rats. Finally, there were no differences in mRNA expression for CCK-1R and LepR in the nodose ganglia of DIO and DR rats. CONCLUSIONS Development of DIO may be partly due to decreased fat-induced satiation through low levels of endogenous satiety peptides, and changes in intestinal nutrient receptors.
Collapse
Affiliation(s)
- F A Duca
- INRA, Centre de Recherche de Jouy-en-Josas, UMR 1319, MICALIS, Neurobiology of Ingestive Behavior, Domaine de Vilvert, Jouy-en-Josas, France
| | | | | | | |
Collapse
|
36
|
Hafez E, Takahashi T, Ogawa H, Sato M, Nakai T, Takasu C, Uehara H, Izumi K. High susceptibility to zymbal gland and intestinal carcinogenesis in diabetic Otsuka long-evans Tokushima Fatty rats. J Toxicol Pathol 2012; 24:187-93. [PMID: 22319230 PMCID: PMC3266353 DOI: 10.1293/tox.24.187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 06/30/2011] [Indexed: 11/19/2022] Open
Abstract
Diabetes mellitus (DM) and obesity are believed to be risk factors for colorectal cancer
in humans. In experiment 1, male nondiabetic Long-Evans Tokushima Otsuka (LETO) rats and
Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model animal of type 2 DM, were
whole-body X-irradiated (4 Gy) at 6 and 8 weeks of age and euthanized at 78 weeks of age
(n=15, respectively). The incidences of small intestine adenocarcinoma in LETO and OLETF
rats were 0% and 30%, respectively. In experiment 2, male LETO and OLETF rats (n=24,
respectively) were given s.c. injections of 15 mg/kg azoxymethane (AOM) once weekly for 3
weeks and euthanized at 36 weeks of age. The incidences of Zymbal gland tumors in LETO and
OLETF rats were 0% and 67%, respectively (P<0.001), whereas those of
small intestine adenocarcinoma were 0% and 43% (P<0.001) and those of
cecum/colon adenocarcinoma were 46% and 79% (P<0.05), respectively.
Fatty change of hepatocytes was common in OLETF rats (63%) but not in LETO rats. Serum
triglyceride and free fatty acid levels in OLETF rats were significantly higher than in
LETO rats at sacrifice, whereas serum insulin levels in OLETF rats were very diverse.
These data suggest that hyperlipidemia plays a significant role in high susceptibility to
lower intestinal tract carcinogenesis in OLETF rats; this strain is susceptible to
AOM-induced Zymbal gland carcinogenesis.
Collapse
Affiliation(s)
- Ezar Hafez
- Department of Molecular and Environmental Pathology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Tarabra E, Pelengaris S, Khan M. A simple matter of life and death-the trials of postnatal Beta-cell mass regulation. Int J Endocrinol 2012; 2012:516718. [PMID: 22577380 PMCID: PMC3346985 DOI: 10.1155/2012/516718] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/31/2011] [Indexed: 12/17/2022] Open
Abstract
Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.
Collapse
Affiliation(s)
- Elena Tarabra
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
- *Elena Tarabra:
| | - Stella Pelengaris
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Michael Khan
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
| |
Collapse
|
38
|
Fukumura T, Kose H, Takeda C, Kurita Y, Ochiai K, Yamada T, Matsumoto K. Genetic interaction between hyperglycemic QTLs is manifested under a high calorie diet in OLETF-derived congenic rats. Exp Anim 2011; 60:125-32. [PMID: 21512267 DOI: 10.1538/expanim.60.125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The condition of hyperglycemia results from multiple genetic and environmental factors. In recent years much progress has been made with regards to the search for candidate genes involved in the expression of various common diseases including type 2 diabetes. However less is known about the specific genetic and environmental connections that are important for the development of the disease. In the present study, we used hyperglycemic congenic rats to address this issue. When given a normal diet, two hyperglycemic QTLs (quantitative trait locus), Nidd2/of and Nidd10/of, showed mild obesity and/or increased blood glucose in the oral glucose tolerance test. In a double congenic strain possessing both loci, these indices were not significantly different from those of either single congenic strain. In contrast, the double congenic strain fed a high-calorie diet showed significantly greater body weight than the single congenic strains or normoglycemic control rats. Although postprandial glucose levels of the double congenic rat were not further aggravated even on the high fat diet, it was notable that the postprandial insulin levels were drastically elevated. From these results, we constructed a novel model animal especially for the study of prediabetic hyperinsulemia, in which two QTLs and an additional dietary condition are involved. This may help to shed light on the genetic basis and gene-to-diet interaction during the early stage of type 2 diabetes.
Collapse
Affiliation(s)
- Tomoe Fukumura
- Division for Animal Research Resources, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
| | | | | | | | | | | | | |
Collapse
|
39
|
Zhu G, Yan J, Smith WW, Moran TH, Bi S. Roles of dorsomedial hypothalamic cholecystokinin signaling in the controls of meal patterns and glucose homeostasis. Physiol Behav 2011; 105:234-41. [PMID: 21871472 DOI: 10.1016/j.physbeh.2011.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/22/2011] [Accepted: 08/08/2011] [Indexed: 10/17/2022]
Abstract
A role for dorsomedial hypothalamus (DMH) cholecystokinin (CCK) signaling in feeding control has been proposed. Administration of CCK into the DMH reduces food intake and OLETF rats lacking CCK1 receptors (CCK1R) become hyperphagic and obese. We hypothesized that site specific replenishment of CCK1R in the DMH of OLETF rats would attenuate aspects of their feeding deficits. Recombinant vectors of adeno-associated viral (AAV)-mediated expression of CCK1R (AAVCCK1R) were bilaterally delivered into the DMH of OLETF. OLETF rats with AAVCCK1R injections demonstrated a 65% replenishment of Cck1r mRNA expression in the DMH relative to lean LETO control rats. Although this level of replenishment did not significantly affect overall food intake or body weight through 14 weeks following viral injections, meal patterns were partially normalized in OLETF rats receiving AAVCCK1R with a significant decrease in dark cycle meal size and a small but significant decrease in daily food intake in the meal analysis chambers. Importantly, the elevation in blood glucose level of OLETF rats was attenuated by the AAVCCK1R injections (p=0.03), suggesting a role for DMH CCK signaling in glucose homeostasis. In support of this role, administration of CCK into the DMH of intact rats enhanced glucose tolerance, as this occurred through activation of CCK1R but not CCK2R signaling. In conclusion, partial replenishment of CCK1R in the DMH of OLETF rats, although insufficient for altering overall food intake and body weight, normalizes meal pattern changes and reduces blood glucose levels. Our study also shows a novel role of DMH CCK signaling in glucose homeostasis.
Collapse
Affiliation(s)
- Guangjing Zhu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, 710061, China
| | | | | | | | | |
Collapse
|
40
|
Inoue N, Nagao K, Sakata K, Yamano N, Gunawardena PER, Han SY, Matsui T, Nakamori T, Furuta H, Takamatsu K, Yanagita T. Screening of soy protein-derived hypotriglyceridemic di-peptides in vitro and in vivo. Lipids Health Dis 2011; 10:85. [PMID: 21600040 PMCID: PMC3116501 DOI: 10.1186/1476-511x-10-85] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 05/22/2011] [Indexed: 11/17/2022] Open
Abstract
Background Soy protein and soy peptides have attracted considerable attention because of their potentially beneficial biological properties, including antihypertensive, anticarcinogenic, and hypolipidemic effects. Although soy protein isolate contains several bioactive peptides that have distinct physiological activities in lipid metabolism, it is not clear which peptide sequences are responsible for the triglyceride (TG)-lowering effects. In the present study, we investigated the effects of soy protein-derived peptides on lipid metabolism, especially TG metabolism, in HepG2 cells and obese Otsuka Long-Evans Tokushima fatty (OLETF) rats. Results In the first experiment, we found that soy crude peptide (SCP)-LD3, which was prepared by hydrolyze of soy protein isolate with endo-type protease, showed hypolipidemic effects in HepG2 cells and OLETF rats. In the second experiment, we found that hydrophilic fraction, separated from SCP-LD3 with hydrophobic synthetic absorbent, revealed lipid-lowering effects in HepG2 cells and OLETF rats. In the third experiment, we found that Fraction-C (Frc-C) peptides, fractionated from hydrophilic peptides by gel permeation chromatography-high performance liquid chromatography, significantly reduced TG synthesis and apolipoprotein B (apoB) secretion in HepG2 cells. In the fourth experiment, we found that the fraction with 0.1% trifluoroacetic acid, isolated from Frc-C peptides by octadecylsilyl column chromatography, showed hypolipidemic effects in HepG2 cells. In the final experiment, we found that 3 di-peptides, Lys-Ala, Val-Lys, and Ser-Tyr, reduced TG synthesis, and Ser-Tyr additionally reduced apoB secretion in HepG2 cells. Conclusion Novel active peptides with TG-lowering effects from soy protein have been isolated.
Collapse
Affiliation(s)
- Nao Inoue
- Department of Applied Biochemistry and Food Science, Saga University, Saga 840-8502, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Chao PT, Terrillion CE, Moran TH, Bi S. High-fat diet offsets the long-lasting effects of running-wheel access on food intake and body weight in OLETF rats. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1459-67. [PMID: 21368270 DOI: 10.1152/ajpregu.00517.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously demonstrated that running-wheel access normalizes the food intake and body weight of Otsuka Long-Evens Tokushima Fatty (OLETF) rats. Following 6 wk of running-wheel access beginning at 8 wk of age, the body weight of OLETF rats remains reduced, demonstrating a lasting effect on their phenotype. In contrast, access to a high-fat diet exacerbates the hyperphagia and obesity of OLETF rats. To determine whether diet modulates the long-term effects of exercise, we examined the effects of high-fat diet on food intake and body weight in OLETF rats that had prior access to running wheels for 4 wk. We found that 4 wk of running exercise significantly decreased food intake and body weight of OLETF rats. Consistent with prior results, 4 wk of exercise also produced long-lasting effects on food intake and body weight in OLETF rats fed a regular chow. When running wheels were relocked, OLETF rats stabilized at lower levels of body weight than sedentary OLETF rats. However, access to a high-fat diet offset these effects. When OLETF rats were switched to a high-fat diet following wheel relocking, they significantly increased food intake and body weight, so that they reached levels similar to those of sedentary OLETF rats fed a high-fat diet. Gene expression determination of hypothalamic neuropeptides revealed changes that appeared to be appropriate responses to the effects of diet and running exercise. Together, these results demonstrate that high-fat diet modulates the long-lasting effects of exercise on food intake and body weight in OLETF rats.
Collapse
Affiliation(s)
- Pei-Ting Chao
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | |
Collapse
|
42
|
Abstract
Type 2 diabetes occurs due to a relative deficit in β-cell mass or function. Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), and gastrin are gastrointestinal hormones that are secreted in response to nutrient intake, regulating digestion, insulin secretion, satiety, and β-cell mass. In this review, we focus upon β-cell mass regulation. β-cell mass expands through β-cell proliferation and islet neogenesis; β-cell mass is lost via apoptosis. GLP-1 and GIP are well-studied gastrointestinal hormones and influence β-cell proliferation, apoptosis, and islet neogenesis. CCK regulates β-cell apoptosis and mitogenesis, and gastrin stimulates islet neogenesis. GLP-1 and GIP bind to G protein-coupled receptors and regulate β-cell mass via multiple signaling pathways. The protein kinase A pathway is central to this process because it directly regulates proliferative and anti-apoptotic genes and transactivates several signaling cascades, including Akt and mitogen-activated protein kinases. However, the signaling pathways downstream of G protein-coupled CCK receptors that influence β-cell mass remain unidentified. Gastrointestinal hormones integrate nutrient signals from the gut to the β-cell, regulating insulin secretion and β-cell mass adaptation.
Collapse
Affiliation(s)
- Jeremy A Lavine
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | |
Collapse
|
43
|
Hajnal A, Kovacs P, Ahmed T, Meirelles K, Lynch CJ, Cooney RN. Gastric bypass surgery alters behavioral and neural taste functions for sweet taste in obese rats. Am J Physiol Gastrointest Liver Physiol 2010; 299:G967-79. [PMID: 20634436 PMCID: PMC2957340 DOI: 10.1152/ajpgi.00070.2010] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Roux-en-Y gastric bypass surgery (GBS) is the most effective treatment for morbid obesity. GBS is a restrictive malabsorptive procedure, but many patients also report altered taste preferences. This study investigated the effects of GBS or a sham operation (SH) on body weight, glucose tolerance, and behavioral and neuronal taste functions in the obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats lacking CCK-1 receptors and lean controls (LETO). OLETF-GBS rats lost body weight (-26%) and demonstrated improved glucose tolerance. They also expressed a reduction in 24-h two-bottle preference for sucrose (0.3 and 1.0 M) and decreased 10-s lick responses for sucrose (0.3 through 1.5 M) compared with OLETF-SH or LETO-GBS. A similar effect was noted for other sweet compounds but not for salty, sour, or bitter tastants. In lean rats, GBS did not alter responses to any stimulus tested. Extracellular recordings from 170 taste-responsive neurons of the pontine parabrachial nucleus revealed a rightward shift in concentration responses to oral sucrose in obese compared with lean rats (OLETF-SH vs. LETO-SH): overall increased response magnitudes (above 0.9 M), and maximum responses occurring at higher concentrations (+0.46 M). These effects were reversed by GBS, and neural responses in OLETF-GBS were statistically not different from those in any LETO groups. These findings confirm obesity-related alterations in taste functions and demonstrate the ability of GBS to alleviate these impairments. Furthermore, the beneficial effects of GBS appear to be independent of CCK-1 receptor signaling. An understanding of the underlying mechanisms for reduced preferences for sweet taste could help in developing less invasive treatments for obesity.
Collapse
Affiliation(s)
- Andras Hajnal
- Dept. of Neural and Behavioral Sciences, The Milton S. Hershey Medical Center, The Pennsylvania State Univ., Hershey, PA 17033, USA.
| | | | | | | | - Christopher J. Lynch
- 3Department of Cellular and Molecular Physiology, The Milton S. Hershey Medical Center, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | | |
Collapse
|
44
|
Peitl B, Döbrönte R, Drimba L, Sári R, Varga A, Németh J, Pázmány T, Szilvássy Z. Involvement of cholecystokinin in baseline and post-prandial whole body insulin sensitivity in rats. Eur J Pharmacol 2010; 644:251-6. [PMID: 20624386 DOI: 10.1016/j.ejphar.2010.06.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 06/06/2010] [Accepted: 06/24/2010] [Indexed: 10/19/2022]
|
45
|
Covasa M. Deficits in gastrointestinal responses controlling food intake and body weight. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1423-39. [PMID: 20861277 DOI: 10.1152/ajpregu.00126.2010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The gastrointestinal tract serves as a portal sensing incoming nutrients and relays mechanical and chemosensory signals of a meal to higher brain centers. Prolonged consumption of dietary fat causes adaptive changes within the alimentary, metabolic, and humoral systems that promote a more efficient process for energy metabolism from this rich source, leading to storage of energy in the form of adipose tissue. Furthermore, prolonged ingestion of dietary fats exerts profound effects on responses to signals involved in termination of a meal. This article reviews the effects of ingested fat on gastrointestinal motility, hormone release, and neuronal substrates. It focuses on changes in sensitivity to satiation signals resulting from chronic ingestion of high-fat diet, which may lead to disordered appetite and dysregulation of body weight.
Collapse
Affiliation(s)
- Mihai Covasa
- L'Institute National de la Recherche Agronomique, Centre de Recherche, Microbiologie de l'Alimentation au service de la Santé Humaine (MICALIS), Neurobiology of Ingestive Behavior, Jouy-en-Josas, France.
| |
Collapse
|
46
|
Nagao K, Yamano N, Shirouchi B, Inoue N, Murakami S, Sasaki T, Yanagita T. Effects of citrus auraptene (7-geranyloxycoumarin) on hepatic lipid metabolism in vitro and in vivo. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:9028-9032. [PMID: 20681532 DOI: 10.1021/jf1020329] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Recent reports have shown that citrus auraptene (7-geranyloxycoumarin) possesses valuable pharmacological properties, including anticarcinogenic, anti-inflammatory, antihelicobacter, antigenotoxic, and neuroprotective effects. In the present study, we investigated the effect of dietary auraptene on hepatic lipid metabolism both in vitro and in vivo. Results suggested that auraptene has the ability to normalize lipid abnormalities in HepG2 hepatocytes. After 4 weeks of auraptene feeding, abdominal white adipose tissue weight and hepatic triglyceride (TG) levels were dose-dependently lowered in Otsuka Long-Evans Tokushima fatty (OLETF) rats. The activities of carnitine palmitoyltransferase, a key enzyme in mitochondrial fatty acid β-oxidation, and peroxisomal β-oxidation were markedly and dose-dependently enhanced in OLETF rat livers by auraptene feeding. Additionally, hepatic expression of acyl-CoA oxidase, the initial enzyme of the peroxisomal β-oxidation system, was significantly and dose-dependently enhanced by auraptene administration. These results suggest that auraptene administration alleviates obesity and hepatic TG accumulation in part through lipolysis enhancement in the livers of obese OLETF rats.
Collapse
Affiliation(s)
- Koji Nagao
- Laboratory of Nutrition Biochemistry, Department of Applied Biochemistry and Food Science, Saga University, Saga 840-8502, Japan
| | | | | | | | | | | | | |
Collapse
|
47
|
Zamami Y, Fujiwara H, Hosoda M, Hino H, Hirai K, Okamoto K, Jin X, Takatori S, Doi-Takaki S, Kawasaki H. [Ameliorative effect of propolis on insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats]. YAKUGAKU ZASSHI 2010; 130:833-40. [PMID: 20519861 DOI: 10.1248/yakushi.130.833] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Propolis is known to have abundant bioactive constituents and a variety of biological activities. To investigate the effect of Brazilian propolis on insulin resistance, 10-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a non-insulin-dependent type 2 diabetic model, were treated for 4 weeks with propolis (100 and 300 mg/kg, p.o.) or vehicle (control). Propolis treatment significantly decreased the plasma levels of insulin and insulin resistance index (Homeostasis Model Assessment-Insulin Resistance; HOM-IR), without affecting blood glucose levels and tended to lower systolic blood pressure compared with the control. In isolated and perfused mesenteric vascular beds of OLETF rats, propolis treatment resulted in significant reduction of sympathetic nerve-mediated vasoconstrictor response to periarterial nerve stimulation (PNS) and tended to increase calcitonin gene-related peptide (CGRP) nerve-mediated vasodilator response to PNS compared with in vehicle-treated OLETF rats. However, propolis treatment did not significantly affect the vasoconstrictor and vasodilator response to noradrenaline, CGRP, acetylcholine, and sodium nitroprusside. These results suggest that propolis could be an effective and functional food to prevent development of insulin resistance.
Collapse
Affiliation(s)
- Yoshito Zamami
- Department of Clinical Pharmaceutical Science, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Lavine JA, Raess PW, Stapleton DS, Rabaglia ME, Suhonen JI, Schueler KL, Koltes JE, Dawson JA, Yandell BS, Samuelson LC, Beinfeld MC, Davis DB, Hellerstein MK, Keller MP, Attie AD. Cholecystokinin is up-regulated in obese mouse islets and expands beta-cell mass by increasing beta-cell survival. Endocrinology 2010; 151:3577-88. [PMID: 20534724 PMCID: PMC2940525 DOI: 10.1210/en.2010-0233] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
An absolute or functional deficit in beta-cell mass is a key factor in the pathogenesis of diabetes. We model obesity-driven beta-cell mass expansion by studying the diabetes-resistant C57BL/6-Leptin(ob/ob) mouse. We previously reported that cholecystokinin (Cck) was the most up-regulated gene in obese pancreatic islets. We now show that islet cholecystokinin (CCK) is up-regulated 500-fold by obesity and expressed in both alpha- and beta-cells. We bred a null Cck allele into the C57BL/6-Leptin(ob/ob) background and investigated beta-cell mass and metabolic parameters of Cck-deficient obese mice. Loss of CCK resulted in decreased islet size and reduced beta-cell mass through increased beta-cell death. CCK deficiency and decreased beta-cell mass exacerbated fasting hyperglycemia and reduced hyperinsulinemia. We further investigated whether CCK can directly affect beta-cell death in cell culture and isolated islets. CCK was able to directly reduce cytokine- and endoplasmic reticulum stress-induced cell death. In summary, CCK is up-regulated by islet cells during obesity and functions as a paracrine or autocrine factor to increase beta-cell survival and expand beta-cell mass to compensate for obesity-induced insulin resistance.
Collapse
Affiliation(s)
- Jeremy A Lavine
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Okamoto S, Shimizu M, Mizuno A, Higuchi T. Estrogens inhibit food intake in CCK-1 receptor-deficient rats. J Physiol Sci 2010; 60:267-71. [PMID: 20495898 PMCID: PMC10717953 DOI: 10.1007/s12576-010-0094-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 04/13/2010] [Indexed: 02/03/2023]
Abstract
In human and many other animals, estrogens inhibit food intake and increases spontaneous activity. Previous studies hypothesized that the anorexigenic effect of estrogens is mediated by the cholecystokinin (CCK)-induced satiety effect. In the present study, we investigated whether estrogens-induced anorexigenic and hyper-active effects are present in Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rat, which is deficient in the CCK1 receptor. In OLETF rats with a regular 4-day estrous cycle, food intake decreased and spontaneous activity increased significantly more during estrus than diestrus as compared to control Long-Evans-Tokushima-Otsuka (LETO) rats. Subcutaneous injection of estradiol benzoate into ovariectomized OLETF rats significantly decreased feeding and increased spontaneous activity to the same extent as in LETO rats. These results suggest that the anorexigenic and hyper-active effects of estrogen can be mediated via pathways other than CCK-CCK1 receptor signaling pathway in CCK1 receptor-deficient rats.
Collapse
Affiliation(s)
- Shuichi Okamoto
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Maki Shimizu
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Akiko Mizuno
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| | - Takashi Higuchi
- Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Matsuoka Fukui, 910-1193 Japan
| |
Collapse
|
50
|
Shirouchi B, Nagao K, Furuya K, Nagai T, Ichioka K, Tokairin S, Iida Y, Yanagita T. Physiological Functions of iso-type Short-Chain Fatty Acid and Omega 3 Polyunsaturated Fatty Acids Containing Oil in Obese OLETF Rats. J Oleo Sci 2010; 59:299-305. [DOI: 10.5650/jos.59.299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|