1
|
Saga S, Sasaki N, Arai T. Molecular identification, characterization, and structure analysis of house musk shrew ( Suncus murinus) leptin. J Adv Vet Anim Res 2018; 6:1-8. [PMID: 31453164 PMCID: PMC6702923 DOI: 10.5455/javar.2019.f305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 11/28/2018] [Accepted: 12/01/2018] [Indexed: 11/24/2022] Open
Abstract
Objective: House musk shrew (Suncus murinus), a small experimental animal with low body fat, may be a possible model for human lipodystrophy. Leptin is an adipocyte-derived hormone thought to have an important role in the pathophysiology of lipodystrophy. The objectives of this study were to clarify the structure and distribution of suncus leptin. Materials and methods: To determine the primary structure of suncus leptin, we cloned the suncus Lep cDNA using the rapid amplification of cDNA ends method. The obtained amino acid (aa) sequence was compared with other mammals and the protein structure prediction was performed. Results: The suncus Lep cDNA encodes 170 aa. The putative suncus leptin precursor has a predicted signal peptide of 21 aa, and the mature leptin comprises 149 aa. The mature leptin is 75%–82% homologous to that of other species. Insertion of the three aa, VPQ, not seen in other mammals was found. This VPQ insertion is thought to be due to a nucleotide insertion of nine bases by slippage-like microindels. The predicted 3D structure of suncus leptin exhibited a typical four a-helix structure, however, the VPQ region protruded compared with human leptin. Lep mRNA expression was observed only in white and brown adipose tissues. Conclusion: This study revealed the structure and distribution of suncus leptin. Because the addition of VPQ, which is not found in other mammals, was observed, suncus leptin attracts attention to its physiological action, and to the possibility of being a model of human lipodystrophy.
Collapse
Affiliation(s)
- Sayaka Saga
- Laboratory of Veterinary Biochemistry, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo, Japan
| | - Noriyasu Sasaki
- Laboratory of Veterinary Biochemistry, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo, Japan
| | - Toshiro Arai
- Laboratory of Veterinary Biochemistry, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo, Japan
| |
Collapse
|
2
|
Mellouk N, Ramé C, Barbe A, Grandhaye J, Froment P, Dupont J. Chicken Is a Useful Model to Investigate the Role of Adipokines in Metabolic and Reproductive Diseases. Int J Endocrinol 2018; 2018:4579734. [PMID: 30018639 PMCID: PMC6029501 DOI: 10.1155/2018/4579734] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/16/2018] [Indexed: 01/04/2023] Open
Abstract
Reproduction is a complex and essential physiological process required by all species to produce a new generation. This process involves strict hormonal regulation, depending on a connection between the hypothalamus-pituitary-gonadal axis and peripheral organs. Metabolic homeostasis influences the reproductive functions, and its alteration leads to disturbances in the reproductive functions of humans as well as animals. For a long time, adipose tissue has been recognised as an endocrine organ but its ability to secrete and release hormones called adipokines is now emerging. Adipokines have been found to play a major role in the regulation of metabolic and reproductive processes at both central and peripheral levels. Leptin was initially the first adipokine that has been described to be the most involved in the metabolism/reproduction interrelation in mammals. In avian species, the role of leptin is still under debate. Recently, three novel adipokines have been discovered: adiponectin (ADIPOQ, ACRP30), visfatin (NAMPT, PBEF), and chemerin (RARRES2, TIG2). However, their mode of action between mammalian and nonmammalian species is different due to the different reproductive and metabolic systems. Herein, we will provide an overview of the structure and function related to metabolic and reproductive mechanisms of the latter three adipokines with emphasis on avian species.
Collapse
Affiliation(s)
- Namya Mellouk
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Christelle Ramé
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Alix Barbe
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Jérémy Grandhaye
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Pascal Froment
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| | - Joëlle Dupont
- INRA, UMR 85 Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France
| |
Collapse
|
3
|
de Godoy MRC, Swanson KS. COMPANION ANIMALS SYMPOSIUM: Nutrigenomics: Using gene expression and molecular biology data to understand pet obesity1. J Anim Sci 2013; 91:2949-64. [DOI: 10.2527/jas.2012-5860] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- M. R. C. de Godoy
- Department of Animal Sciences, University of Illinois, Urbana, IL 61801
| | - K. S. Swanson
- Department of Animal Sciences, University of Illinois, Urbana, IL 61801
- Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801
- Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL 61801
| |
Collapse
|
4
|
Natural selection and adaptive evolution of leptin. CHINESE SCIENCE BULLETIN-CHINESE 2013. [DOI: 10.1007/s11434-012-5635-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
5
|
Koch E, Hue-Beauvais C, Galio L, Solomon G, Gertler A, Révillon F, Lhotellier V, Aujean E, Devinoy E, Charlier M. Leptin gene in rabbit: cloning and expression in mammary epithelial cells during pregnancy and lactation. Physiol Genomics 2013; 45:645-52. [PMID: 23715260 DOI: 10.1152/physiolgenomics.00020.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leptin is known as a cytokine mostly produced by fat cells and implicated in regulation of energy metabolism and food intake but has also been shown to be involved in many physiological mechanisms such as tissue metabolism and cell differentiation and proliferation. In particular, leptin influences the development of mammary gland. Although leptin expression in mammary gland has been studied in several species, no data are available in the rabbit. Leptin transcripts in this species have been described as being encoded by only two exons rather than three as in other species. Our focus was to clone and sequence the rabbit leptin cDNA and to prepare the recombinant biologically active protein for validation of the proper sequence and then to describe leptin expression in rabbit mammary gland during different stages of pregnancy and lactation. The leptin sequence obtained was compared with those of other species, and genome alignment demonstrated that the rabbit leptin gene is also encoded by three exons. Additionally, we analyzed the expression of leptin during pregnancy and lactation. Leptin mRNA was weakly expressed throughout pregnancy, whereas mRNA levels were higher during lactation, with a significant increase between days 3 and 16. Leptin transcripts and protein were localized in luminal epithelial cells, thus indicating that leptin synthesis occurs in this compartment. Therefore, mammary synthesized leptin may constitute a major regulator of mammary gland development by acting locally as an autocrine and/or paracrine factor. Furthermore, our results support the possible physiological role of leptin in newborns through consumption of milk.
Collapse
Affiliation(s)
- Emmanuelle Koch
- INRA, UR1196, Génomique et Physiologie de la Lactation, Jouy-en-Josas, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Tao YX, Yuan ZH, Xie J. G Protein-Coupled Receptors as Regulators of Energy Homeostasis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:1-43. [DOI: 10.1016/b978-0-12-386933-3.00001-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
7
|
Preliminary report on the expression of leptin and leptin receptor (ObR) in normal, hyperplastic and neoplastic canine mammary tissues. Res Vet Sci 2012; 93:343-9. [DOI: 10.1016/j.rvsc.2011.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 07/18/2011] [Accepted: 07/22/2011] [Indexed: 12/23/2022]
|
8
|
Verkest KR, Rose FJ, Fleeman LM, Rand JS, Morton JM, Richards AA, Ishioka K, Whitehead JP. Adiposity and adiponectin in dogs: investigation of causes of discrepant results between two studies. Domest Anim Endocrinol 2011; 41:35-41. [PMID: 21645805 DOI: 10.1016/j.domaniend.2011.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 03/01/2011] [Accepted: 03/31/2011] [Indexed: 02/03/2023]
Abstract
Although one study showed lower adiponectin concentrations in obese dogs, other recent studies indicate that adiponectin might not be decreased in obese dogs, raising the possibility that the physiology of adiponectin is different in dogs than in humans. The aim of this study was to investigate possible causes of the discrepancy between the two largest studies to date that assessed the association between adiposity and adiponectin concentration in dogs, including the validity of the assay, laboratory error, and the effects of breed, sex, and neuter status on the relationship between adiposity and adiponectin concentrations. Adiponectin concentrations measured with a previously validated adiponectin ELISA were compared with those estimated by Western blotting analysis of reduced and denatured plasma samples. The possibility of laboratory error and the effect of EDTA anticoagulant and aprotinin were tested. Adiponectin concentration was measured by ELISA in 20 lean dogs (10 male and 10 female, 5 neutered in each sex). There was close correlation between adiponectin concentrations measured by ELISA and those estimated by Western blotting analysis (r = 0.90; P < 0.001). There was no substantial effect of EDTA, aprotinin, or laboratory error on the results. There was confounding by neuter status of the relationship between adiposity and adiponectin concentrations, but adiponectin concentrations were not significantly lower in male than in female lean dogs (females, 36 mg/L; males, 26 mg/L; P > 0.20) and were not significantly lower in intact than in neutered lean male dogs (intact, 28 mg/L; neutered, 23 mg/L; P = 0.49). We conclude that the adiponectin ELISA previously validated for use in dogs appears to be suitable for determination of canine adiponectin concentrations and that testosterone does not appear to have a strong effect on plasma adiponectin concentrations in dogs. Obesity might decrease adiponectin concentrations in intact but not in neutered dogs.
Collapse
Affiliation(s)
- K R Verkest
- Centre for Companion Animal Health, School of Veterinary Science, The University of Queensland, Brisbane, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Ricci R, Bevilacqua F. The potential role of leptin and adiponectin in obesity: a comparative review. Vet J 2011; 191:292-8. [PMID: 21592831 DOI: 10.1016/j.tvjl.2011.04.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 04/01/2011] [Accepted: 04/04/2011] [Indexed: 10/18/2022]
Abstract
Leptin and adiponectin are adipokines produced by the white adipose tissue. The adipokines have been shown to be valuable quantitative markers of adiposity in dogs. Leptin positively correlates with body condition score (BCS) in dogs, regardless of age, sex and breed, and is influenced by feeding state, pharmacological treatment and thyroid gland activity. Conversely, adiponectin negatively correlates with body fat mass and is therefore more abundant in lean animals. The implication of leptin and adiponectin in the pathogenesis of metabolic syndrome is well established in humans, but currently lacking in dogs. Additional studies are necessary to demonstrate their potential usefulness for monitoring the progression of obesity-related diseases and response to treatment. To date, measurement of canine leptin and adiponectin has been used in experimental studies only, whereas bodyweight and BCS are considered the first-approach parameters for the routine assessment of body fat content in obese dogs.
Collapse
Affiliation(s)
- Rebecca Ricci
- Department of Animal Science, University of Padua, Viale dell'Università 12 and 16, 35020 Legnaro (PD), Italy.
| | | |
Collapse
|
10
|
Zoran DL. Obesity in dogs and cats: a metabolic and endocrine disorder. Vet Clin North Am Small Anim Pract 2010; 40:221-39. [PMID: 20219485 DOI: 10.1016/j.cvsm.2009.10.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Obesity is defined as an accumulation of excessive amounts of adipose tissue in the body, and has been called the most common nutritional disease of dogs in Western countries. Most investigators agree that at least 33% of the dogs presented to veterinary clinics are obese, and that the incidence is increasing as human obesity increases in the overall population. Obesity is not just the accumulation of large amounts of adipose tissue, but is associated with important metabolic and hormonal changes in the body, which are the focus of this review. Obesity is associated with a variety of conditions, including osteoarthritis, respiratory distress, glucose intolerance and diabetes mellitus, hypertension, dystocia, decreased heat tolerance, some forms of cancer, and increased risk of anesthetic and surgical complications. Prevention and early recognition of obesity, as well as correcting obesity when it is present, are essential to appropriate health care, and increases both the quality and quantity of life for pets.
Collapse
Affiliation(s)
- Debra L Zoran
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA.
| |
Collapse
|
11
|
Xu Q, Zhang X, Han N, Shou J, Hou R, Zhang Z, Bian H, Zhu M. Characterization and expression of Ailuropoda melanoleuca leptin (ob gene). Zoolog Sci 2010; 27:41-6. [PMID: 20064007 DOI: 10.2108/zsj.27.41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Leptin, an adipocyte-derived hormone, plays important roles in metabolism and reproduction. In this article, we report the cloning, expression, and identification of the giant panda leptin (gLeptin) gene and its variants. The gLeptin cDNA was 504 bp long, encoding a precursor peptide of 167 amino acids including 21 residues of signal peptide. A short variant of gLeptin was 501 bp long, encoding a 166-aa peptide and also including a 21-aa signal peptide. Giant panda leptin was 99.4%, 94.6%, and 92.8% identical to that of black bear, dog, and cat, respectively, but was only 81.4% and 80.8% identical to that of human and rat. The cloned gLeptin gene was expressed in Escherichia coli, with expression confirmed by Western blotting and MALDI-TOF-TOF MS PMF. After purification, renaturation, and condensation, the gLeptin protein was injected into Kunming mice. The recombinant gLeptin significantly inhibited food intake by 41.8% and reduced body weight by 5.1% in the mice.
Collapse
Affiliation(s)
- Qinggang Xu
- The Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou, China
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Radin MJ, Sharkey LC, Holycross BJ. Adipokines: a review of biological and analytical principles and an update in dogs, cats, and horses. Vet Clin Pathol 2009; 38:136-56. [DOI: 10.1111/j.1939-165x.2009.00133.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
13
|
Schäfer-Somi S, Beceriklisoy HB, Budik S, Kanca H, Aksoy OA, Polat B, Cetin Y, Ay SS, Aslan S. Expression of Genes in the Canine Pre-implantation Uterus and Embryo: Implications for an Active Role of the Embryo Before and During Invasion. Reprod Domest Anim 2008; 43:656-63. [DOI: 10.1111/j.1439-0531.2007.00966.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
14
|
Girard I, Rezende EL, Garland T. Leptin levels and body composition of mice selectively bred for high voluntary locomotor activity. Physiol Biochem Zool 2007; 80:568-79. [PMID: 17909994 DOI: 10.1086/521086] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2007] [Indexed: 11/03/2022]
Abstract
Selective breeding produced four replicate lines of high-runner (HR) mice that run on wheels for approximately 2.7 times more revolutions per day than four unselected control lines. Previous studies found that HR mice of both sexes have lower body fat (isotope dilution at 15 wk of age) and that males (females not studied) have smaller retroperitoneal fat pads (17 wk). HR mice also exhibit elevated plasma corticosterone and insulin-stimulated glucose uptake by some hindlimb muscles but apparently do not differ in circulating insulin or glucose levels (males at 18 wk). Given their lower body fat and higher activity levels, we hypothesized that HR mice would have lower circulating leptin levels than controls. Female mice were given wheel access for 6 d at 7 wk of age, as part of the routine wheel testing for the selective breeding protocol, and then were killed after one additional week without wheels to reduce possible acute effects of activity on leptin. As hypothesized, serum leptin levels were significantly lower in HR mice. ANCOVA indicated that leptin was strongly positively correlated with both total body fat (measured by ether extraction) and body mass change from weaning, but HR mice still had significantly lower adjusted leptin levels (ANCOVA). Within HR lines but not within control lines, individual variation in leptin levels was negatively correlated with amount or speed of wheel running measured a week before being killed. Growth from weaning to euthanasia and body dry mass were lower in HR mice than in controls, but absolute dry masses of the ventricles, liver, gut, and uterus plus ovaries did not significantly differ, nor did percentage of the total dry mass as fat. HR mice offer a novel model for studying the causes and consequences of physiologically relevant variations in serum leptin.
Collapse
Affiliation(s)
- Isabelle Girard
- Department of Biology, University of Wisconsin, 800 Reserve Street, Stevens Point, Wisconsin 54481, USA
| | | | | |
Collapse
|
15
|
Analysis of Single Nucleotide Polymorphisms of Leptin Gene in Hanwoo(Korean Cattle). JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2007. [DOI: 10.5187/jast.2007.49.3.295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
16
|
Ishioka K, Hosoya K, Kitagawa H, Shibata H, Honjoh T, Kimura K, Saito M. Plasma leptin concentration in dogs: effects of body condition score, age, gender and breeds. Res Vet Sci 2006; 82:11-5. [PMID: 16919691 DOI: 10.1016/j.rvsc.2006.06.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 05/05/2006] [Accepted: 06/12/2006] [Indexed: 10/24/2022]
Abstract
Leptin is a cytokine produced by adipocytes, and plays a key role in the regulation of energy balance. In the present study, we measured plasma leptin concentrations of 166 normal and obese dogs visiting veterinary practices, and clarified the influence of age, gender and breed on plasma leptin levels in dogs. Leptin levels were higher in the dogs with higher body condition scores. There was no noticeable influence of age, gender and breed, but those in optimal puppies and obese Miniature Dachshund tended to be lower than those in corresponding groups. We conclude that plasma leptin is a reliable marker of adiposity in dogs regardless of age, gender and breed variations, and thereby useful as a blood biochemistry test for health examinations and treatment of obesity.
Collapse
Affiliation(s)
- K Ishioka
- Department of Veterinary Nursing, School of Veterinary Nursing and Technology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan.
| | | | | | | | | | | | | |
Collapse
|
17
|
Ishioka K, Omachi A, Sagawa M, Shibata H, Honjoh T, Kimura K, Saito M. Canine adiponectin: cDNA structure, mRNA expression in adipose tissues and reduced plasma levels in obesity. Res Vet Sci 2005; 80:127-32. [PMID: 16051287 DOI: 10.1016/j.rvsc.2005.05.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 03/29/2005] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
Adiponectin is a protein synthesized and secreted by adipocytes. Decreased adiponectin is responsible for insulin resistance and atherosclerosis associated with human obesity. We obtained a cDNA clone corresponding to canine adiponectin, whose nucleotide and deduced amino acid sequences were highly identical to those of other species. Adiponectin mRNA was detected in adipose tissues, but not in other tissues, of dogs. When 22 adult beagles were given a high-energy diet for 14 weeks, they became obese, showing heavier body weights, higher plasma leptin concentrations, but lower plasma adiponectin concentrations. The adiponectin concentrations of plasma samples collected from 71 dogs visiting veterinary practices were negatively correlated to plasma leptin concentrations, being lower in obese than non-obese dogs. These results are compatible with those reported in other species, and suggest that adiponectin is an index of adiposity and a target molecule for studies on diseases associated with obesity in dogs.
Collapse
Affiliation(s)
- K Ishioka
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
| | | | | | | | | | | | | |
Collapse
|
18
|
Ishioka K, Hatai H, Komabayashi K, Soliman MM, Shibata H, Honjoh T, Kimura K, Saito M. Diurnal variations of serum leptin in dogs: effects of fasting and re-feeding. Vet J 2005; 169:85-90. [PMID: 15683767 DOI: 10.1016/j.tvjl.2004.01.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/24/2003] [Indexed: 12/21/2022]
Abstract
Leptin is a protein synthesized and secreted primarily by adipocytes, and plays a key role in the regulation of energy balance. We have reported that serum leptin is elevated in obese dogs. In the present study, we examined diurnal variations of serum leptin in the dog, with special references to feeding and fasting cycles. Four male beagles were accustomed to feed once a day at 10:00 h, and blood samples were taken every 3 h for 24-36 h. Serum leptin concentration showed clear diurnal variations, being lowest before food intake (2.3+/-0.5 ng/mL) at 09:00 h, and highest (10.5+/-2.4 ng/mL) at 18:00 h. Such diurnal variations disappeared when the dogs were fasted. Serum insulin also showed diurnal variation with higher levels at 12:00-15:00 h. When insulin or glucose was injected in the fasted dogs to mimic the post-prandial insulin rise, serum leptin concentration was significantly increased in 4-8 h, but in both cases to a lesser extents than those after food intake. The results indicate that serum leptin concentrations change diurnally in association with feeding-fasting cycles in the dog, partially due to changes in insulin secretion.
Collapse
Affiliation(s)
- K Ishioka
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Shibata H, Akahane R, Honjoh T, Asano M, Mominoki K, Fujii K, Suzuki M, Ohtaishi N, Ishioka K, Ahmed M, Soliman M, Kimura K, Saito M. Seasonal changes in serum leptin of the feral raccoon (Procyon lotor) determined by canine-leptin-specific ELISA. ACTA ACUST UNITED AC 2005; 303:527-33. [PMID: 15945076 DOI: 10.1002/jez.a.185] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Several reports have been published on blood leptin concentrations in feral animals, including members of the Carnivora, using a commercially available multi-species radioimmunoassay (RIA) kit with anti-human leptin antibody. However, we observed weak immunoreactivity between recombinant canine leptin and anti-human leptin antibody, suggesting a limitation in the applicability of the RIA kit for leptin assays in Carnivora species. We tested the applicability of RIA and sandwich enzyme-linked immunosorbent assay (ELISA) with anti-canine leptin antibody to assay blood leptin in the dog (Canis familiaris) and the raccoon (Procyon lotor). When RIA was used for recombinant canine leptin and dog sera, values were much lower than those determined by ELISA at higher concentrations (>10 ng/ml), while rather higher at lower concentrations (<2 ng/ml). A similar discrepancy between the two methods was found for serum leptin concentrations in raccoons. Clear seasonal variations were observed by ELISA, but not by RIA, with high values in autumn (3.46+/-0.45 ng/ml) and low values in spring and summer (0.71+/-0.07 ng/ml). Serum leptin concentrations in raccoons correlated positively with their body weight (r=0.753) and body mass index (r=0.755), corroborating our previous findings of a strong positive correlation between serum leptin concentrations and body fat content in dogs. Thus, the canine leptin ELISA is useful for assays of dog and raccoon leptin, and blood leptin is a good marker of nutritional condition in the species of Carnivora assayed in this study.
Collapse
Affiliation(s)
- Haruki Shibata
- Morinaga Institute of Biological Science, Inc., Kanazawa, Yokohama 236-0003, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Tsunoda Y, Yao H, Park J, Owyang C. Cholecystokinin synthesizes and secretes leptin in isolated canine gastric chief cells. Biochem Biophys Res Commun 2003; 310:681-4. [PMID: 14550255 DOI: 10.1016/j.bbrc.2003.08.154] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It is well recognized that a product of obese (ob) locus and body weight control hormone, leptin, acts on both short-term satiety for meal-induced termination of food intake (gastric phase) and long-term satiety for energy expenditure via the hypothalamus. The considerable sources of leptin are chief cells for gastric phase and adipocytes for the long-term satiety. The objective of this study was to demonstrate if CCK enhances leptin synthesis and secretion in isolated canine gastric chief cells. Confocal immunofluorescence studies showed that the CCK-A receptor and leptin were colocalized in the endoplasm. Western blotting demonstrated that canine chief cells expressed the leptin peptide and its protein level was enhanced by CCK treatment. An ELISA further showed that CCK dose-dependently secreted leptin from isolated canine chief cells. This was reproduced by the high-affinity CCK-A receptor agonist, CCK-OPE. These results indicate that canine chief cells synthesize and secrete leptin in response to CCK via the high-affinity state of the CCK-A receptor.
Collapse
Affiliation(s)
- Yasuhiro Tsunoda
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
| | | | | | | |
Collapse
|
21
|
Shibata H, Sasaki N, Honjoh T, Ohishi I, Takiguchi M, Ishioka K, Ahmed M, Soliman M, Kimura K, Saito M. Feline Leptin: Immunogenic and Biological Activities of the Recombinant Protein, and Its Measurement by ELISA. J Vet Med Sci 2003; 65:1207-11. [PMID: 14665750 DOI: 10.1292/jvms.65.1207] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leptin is a protein synthesized and secreted primarily by adipose tissue. The blood leptin concentration is known to reflect body fat content in rodents, humans and dogs, and thereby is useful for quantitative assessment of obesity. In the present study, we produced recombinant feline leptin in Escherichia coli transfected with feline leptin cDNA we cloned previously. The recombinant feline leptin with a molecular weight of 16 kDa induced phosphorylation of the signal transducers and activators of transcription 3 (STAT3) protein in the cells expressing rat leptin receptor. The anti-feline leptin antibody raised in rabbits reacted well to feline and human leptin and less to rodents' leptin in Western blot analysis. Sandwich enzyme-linked immunosorbent assay (ELISA) was developed, using rabbit anti-feline leptin antibody and recombinant feline leptin as a standard. In this ELISA system, cross-reactivity to human, rat and mouse leptin was 30.7%, 69.5% and 66.6%, respectively. The plasma leptin levels of 24 healthy cats were in a range from 0.3 to 29.7 ng/ml with the mean +/- SEM of 4.5 +/- 1.3 ng/ml, being positively proportional to body fat content. These results indicate that our ELISA system may be useful for assessment of obesity in cats.
Collapse
Affiliation(s)
- Haruki Shibata
- Morinaga Institute of Biological Science, Tsurumi, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Ishioka K, Soliman MM, Honjoh T, Shibata H, Kimura K, Saito M. Dexamethasone increases serum leptin concentration in dogs. Vet J 2002; 164:295-7. [PMID: 12505408 DOI: 10.1053/tvjl.2002.0710] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- K Ishioka
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | | | | | | | | | | |
Collapse
|
23
|
Ishioka K, Soliman MM, Sagawa M, Nakadomo F, Shibata H, Honjoh T, Hashimoto A, Kitamura H, Kimura K, Saito M. Experimental and clinical studies on plasma leptin in obese dogs. J Vet Med Sci 2002; 64:349-53. [PMID: 12014581 DOI: 10.1292/jvms.64.349] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leptin is a protein synthesized and secreted primarily by adipocytes, and the circulating leptin concentration is elevated in obese humans and rodents. Recently, we have established a sandwich enzyme-linked immunosorbent assay for canine leptin. In the present study, plasma leptin concentrations were measured in experimentally developed obese beagles and in clinically obese dogs. When 5 male beagles were given a high-energy diet for 3 months, all of them became obese and the plasma leptin concentration significantly increased from 2.4+/-1.2 to 4.9+/-0.9 ng/ml, positively correlating with body fat content estimated by the deuterium oxide dilution method (r=0.87). The leptin concentrations of plasma samples collected from 59 dogs in veterinary practices were compared with their body condition scores (BCS). The plasma leptin concentrations of obese dogs were 9.7+/-0.7 and 12.3+/-1.5 ng/ml at BCS=4 and BCS=5, respectively, which were significantly higher than those of optimal (BCS=3) dogs (2.7+/-0.3 ng/ml). There was no significant effect of sex and breed. A weak positive correlation (r=0.37) was found between the plasma leptin concentration and age, probably due to the lesser content of visceral fat in puppies younger than 1 year old. These results indicate that plasma leptin is a good index of adiposity in dogs regardless of breed, age and sex, and may be useful for quantitative assessment of obesity in small animal practice.
Collapse
Affiliation(s)
- Katsumi Ishioka
- Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Sagawa MM, Nakadomo F, Honjoh T, Ishioka K, Saito M. Correlation between plasma leptin concentration and body fat content in dogs. Am J Vet Res 2002; 63:7-10. [PMID: 16206772 DOI: 10.2460/ajvr.2002.63.7] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the relationship between plasma leptin concentration and body fat content in dogs. ANIMALS 20 spayed female Beagles that were 10 months old at the start of the experiment. PROCEDURE Dogs were kept under regulated feeding and exercise conditions for 21 weeks, resulting in a wide range of body weights, body condition scores (BCS), and subcutaneous thicknesses. Plasma leptin concentration was measured by use of a canine leptin-specific ELISA test to evaluate its correlation to body fat content estimated by the deuterium oxide dilution method. Plasma concentrations of glucose, cholesterol, triglycerides (TG), and nonesterified fatty acids (NEFA) were also measured. RESULTS Body fat content (9 to 60% of body weight) was positively and closely correlated (r = 0.920; n = 20; P < 0.001) to plasma leptin concentration (0.67 to 8.06 ng/ml), compared with other variables (ie, glucose, cholesterol, TG, and NEFA; r = 0.142, 0.412, 0.074, and 0.182, respectively). CONCLUSIONS AND CLINICAL RELEVANCE The positive relationship between plasma leptin concentration and body fat content in dogs was similar to correlations reported for humans and rodents, suggesting that plasma leptin is a quantitative marker of adiposity in dogs.
Collapse
Affiliation(s)
- Mayumi M Sagawa
- Research Center, Nippon Pet Food Co, Ltd, 2020 Umeyama, Asaba, Shizuoka 437-1105, Japan
| | | | | | | | | |
Collapse
|
25
|
Sasaki N, Shibata H, Honjoh T, Kimura K, Saito M, Ohishi I. CDNA cloning of feline leptin and its mRNA expression in adipose tissue. J Vet Med Sci 2001; 63:1115-20. [PMID: 11714028 DOI: 10.1292/jvms.63.1115] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leptin, the product of the obese (ob) gene, is an adipocyte-derived hormone involved in regulating food intake and energy expenditure in humans and rodents. To determine the primary structure of feline leptin, we cloned the feline leptin cDNA using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of complementary DNA (cDNA) ends (RACE) methods. The full-length feline leptin cDNA was 2935 bp with a 501 bp open reading frame encoding the precursor peptide of 167 amino acids including 21 residues of signal peptide. The sequence of a 146-amino acid mature leptin was 81.5-91.8% homologous to those of other species. RT-PCR analysis revealed that the leptin mRNA was expressed in adipose tissues and not detected in liver, heart, kidney, lung, pancreas. brain and skeletal muscle. These data show that feline leptin is highly homologous to leptins of other species, and expressed in adipose tissues in cats.
Collapse
Affiliation(s)
- N Sasaki
- Department of Veterinary Science, Nippon Veterinary and Animal Science University, Musashino, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Park JH, Lee HH, Na SY, Ju SK, Lee YJ, Lee MK, Kim KL. Recombinant expression of biologically active rat leptin in Escherichia coli. Protein Expr Purif 2001; 22:60-9. [PMID: 11388800 DOI: 10.1006/prep.2001.1412] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptin is a 16-kDa nonglycosylated hormone that is produced in mature adipocytes and which acts primarily in the hypothalamus to reduce food intake and body weight. While the rat is a representative laboratory animal model in obesity research, so far recombinant rat leptin was not available. In the present study, rat leptin was recombinantly expressed in Escherichia coli and purified in a bioactive form to provide a further tool for the analysis of leptin functions in rats. Leptin cDNA was cloned by RT-PCR from total RNA of SD rat adipocytes, and overexpression was achieved by subcloning the leptin cDNA into the pET-29a vector, which enabled the recombinant expression of rat leptin as an S-peptide-tagged fusion protein. Since the fusion proteins were expressed in inclusion bodies, after purification of the insoluble fraction, leptin proteins were refolded by sequential dialysis into physiological buffers. The biological activity of this recombinant protein was confirmed in proliferation assays using leptin-sensitive rat insulinoma cells as well as a newly developed leptin-sensitive luciferase assay system. The specific binding of the S-tagged leptin to leptin-receptor-expressing cells was further shown by flow cytometry using fluorescence-conjugated S-proteins.
Collapse
Affiliation(s)
- J H Park
- Protein Engineering Laboratory, Korea Research Institute of Bioscience and Biotechnology, Yusong, Taejon 305-600, Korea
| | | | | | | | | | | | | |
Collapse
|