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Development of Dissociation-Enhanced Lanthanide Fluoroimmunoassay for Measuring Leptin. J Fluoresc 2016; 26:1715-21. [PMID: 27343179 DOI: 10.1007/s10895-016-1862-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
Abstract
Development of a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) for measuring leptin, a satiety hormone of appetite control, was conducted in sandwich assay format exploiting a microplate immobilized with an anti-leptin antibody and another antibody raised against leptin and tagged with an europium chelate. In the leptin DELFIA of this study, amounts of antibody coated to the microplate and of the bioconjugate for the second immune reaction were optimized as 0.5 μg and 200 ng per well, respectively. When plotted in double-logarithmic scale, a linear relationship of y (log10 response signal) = 0.6023× (log10 leptin concentration) + 3.4084 (r(2) = 0.9646) was obtained at the leptin concentrations of 0.01─50 ng/mL with the limit of detection of 0.01 ng/mL. Individual leptin concentrations in various samples were well convergent to the calibration curve of the current assay. When applied to the measurement of leptin in a rat serum, the present assay was found quite effective and was competitive to a commercial sandwich-type ELISA.
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Méquinion M, Chauveau C, Viltart O. The use of animal models to decipher physiological and neurobiological alterations of anorexia nervosa patients. Front Endocrinol (Lausanne) 2015; 6:68. [PMID: 26042085 PMCID: PMC4436882 DOI: 10.3389/fendo.2015.00068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/15/2015] [Indexed: 12/18/2022] Open
Abstract
Extensive studies were performed to decipher the mechanisms regulating feeding due to the worldwide obesity pandemy and its complications. The data obtained might be adapted to another disorder related to alteration of food intake, the restrictive anorexia nervosa. This multifactorial disease with a complex and unknown etiology is considered as an awful eating disorder since the chronic refusal to eat leads to severe, and sometimes, irreversible complications for the whole organism, until death. There is an urgent need to better understand the different aspects of the disease to develop novel approaches complementary to the usual psychological therapies. For this purpose, the use of pertinent animal models becomes a necessity. We present here the various rodent models described in the literature that might be used to dissect central and peripheral mechanisms involved in the adaptation to deficient energy supplies and/or the maintenance of physiological alterations on the long term. Data obtained from the spontaneous or engineered genetic models permit to better apprehend the implication of one signaling system (hormone, neuropeptide, neurotransmitter) in the development of several symptoms observed in anorexia nervosa. As example, mutations in the ghrelin, serotonin, dopamine pathways lead to alterations that mimic the phenotype, but compensatory mechanisms often occur rendering necessary the use of more selective gene strategies. Until now, environmental animal models based on one or several inducing factors like diet restriction, stress, or physical activity mimicked more extensively central and peripheral alterations decribed in anorexia nervosa. They bring significant data on feeding behavior, energy expenditure, and central circuit alterations. Animal models are described and criticized on the basis of the criteria of validity for anorexia nervosa.
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Affiliation(s)
- Mathieu Méquinion
- INSERM UMR-S1172, Development and Plasticity of Postnatal Brain, Lille, France
| | - Christophe Chauveau
- Pathophysiology of Inflammatory Bone Diseases, EA 4490, University of the Littoral Opal Coast, Boulogne sur Mer, France
| | - Odile Viltart
- INSERM UMR-S1172, Early stages of Parkinson diseases, University Lille 1, Lille, France
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Glendinning JI, Elson AET, Kalik S, Sosa Y, Patterson CM, Myers MG, Munger SD. Taste responsiveness to sweeteners is resistant to elevations in plasma leptin. Chem Senses 2015; 40:223-31. [PMID: 25740302 DOI: 10.1093/chemse/bju075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
There is uncertainty about the relationship between plasma leptin and sweet taste in mice. Whereas 2 studies have reported that elevations in plasma leptin diminish responsiveness to sweeteners, another found that they enhanced responsiveness to sucrose. We evaluated the impact of plasma leptin on sweet taste in C57BL/6J (B6) and leptin-deficient ob/ob mice. Although mice expressed the long-form leptin receptor (LepRb) selectively in Type 2 taste cells, leptin failed to activate a critical leptin-signaling protein, STAT3, in taste cells. Similarly, we did not observe any impact of intraperitoneal (i.p.) leptin treatment on chorda tympani nerve responses to sweeteners in B6 or ob/ob mice. Finally, there was no effect of leptin treatment on initial licking responses to several sucrose concentrations in B6 mice. We confirmed that basal plasma leptin levels did not exceed 10ng/mL, regardless of time of day, physiological state, or body weight, suggesting that taste cell LepRb were not desensitized to leptin in our studies. Furthermore, i.p. leptin injections produced plasma leptin levels that exceeded those previously reported to exert taste effects. We conclude that any effect of plasma leptin on taste responsiveness to sweeteners is subtle and manifests itself only under specific experimental conditions.
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Affiliation(s)
- John I Glendinning
- Department of Biology, Barnard College, Columbia University, 3009 Broadway New York, NY 10027, USA,
| | - Amanda E T Elson
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 S. Penn St., Baltimore, MD 21201, USA
| | - Salina Kalik
- Department of Biology, Barnard College, Columbia University, 3009 Broadway New York, NY 10027, USA
| | - Yvett Sosa
- Department of Biology, Barnard College, Columbia University, 3009 Broadway New York, NY 10027, USA
| | - Christa M Patterson
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, MI 48109, USA and
| | - Martin G Myers
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, MI 48109, USA and
| | - Steven D Munger
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, 20 S. Penn St., Baltimore, MD 21201, USA, Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, HH-495, Baltimore, MD 21201, USA
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Méquinion M, Caron E, Zgheib S, Stievenard A, Zizzari P, Tolle V, Cortet B, Lucas S, Prévot V, Chauveau C, Viltart O. Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction? Am J Physiol Endocrinol Metab 2015; 308:E241-55. [PMID: 25465889 DOI: 10.1152/ajpendo.00340.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass.
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Affiliation(s)
- Mathieu Méquinion
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Emilie Caron
- Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France
| | - Sara Zgheib
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Aliçia Stievenard
- University Lille (ULCO, USTL, Lille2), Lille, France; Molecular Events Associated With Early stages of Parkinson's Disease UMR 837 INSERM, Lille, France
| | - Philippe Zizzari
- Psychiatry and Neurosciences Center, UMR 894 INSERM, Paris, France; and
| | - Virginie Tolle
- Psychiatry and Neurosciences Center, UMR 894 INSERM, Paris, France; and
| | - Bernard Cortet
- University Lille (ULCO, USTL, Lille2), Lille, France; Department of Rheumatology, Centre Hospitalier Universitaire Régional, Lille, France
| | - Stéphanie Lucas
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Vincent Prévot
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France
| | - Christophe Chauveau
- University Lille (ULCO, USTL, Lille2), Lille, France; Physiopathology of Inflammatory Bone diseases, EA4490, Boulogne sur Mer, France
| | - Odile Viltart
- University Lille (ULCO, USTL, Lille2), Lille, France; Development and Plasticity of Postnatal Brain, UMR 837 Institut National de la Sante et de la Recherche Medicale (INSERM), Lille, France;
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Zgheib S, Méquinion M, Lucas S, Leterme D, Ghali O, Tolle V, Zizzari P, Bellefontaine N, Legroux-Gérot I, Hardouin P, Broux O, Viltart O, Chauveau C. Long-term physiological alterations and recovery in a mouse model of separation associated with time-restricted feeding: a tool to study anorexia nervosa related consequences. PLoS One 2014; 9:e103775. [PMID: 25090643 PMCID: PMC4121212 DOI: 10.1371/journal.pone.0103775] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022] Open
Abstract
Background Anorexia nervosa is a primary psychiatric disorder, with non-negligible rates of mortality and morbidity. Some of the related alterations could participate in a vicious cycle limiting the recovery. Animal models mimicking various physiological alterations related to anorexia nervosa are necessary to provide better strategies of treatment. Aim To explore physiological alterations and recovery in a long-term mouse model mimicking numerous consequences of severe anorexia nervosa. Methods C57Bl/6 female mice were submitted to a separation-based anorexia protocol combining separation and time-restricted feeding for 10 weeks. Thereafter, mice were housed in standard conditions for 10 weeks. Body weight, food intake, body composition, plasma levels of leptin, adiponectin, IGF-1, blood levels of GH, reproductive function and glucose tolerance were followed. Gene expression of several markers of lipid and energy metabolism was assayed in adipose tissues. Results Mimicking what is observed in anorexia nervosa patients, and despite a food intake close to that of control mice, separation-based anorexia mice displayed marked alterations in body weight, fat mass, lean mass, bone mass acquisition, reproductive function, GH/IGF-1 axis, and leptinemia. mRNA levels of markers of lipogenesis, lipolysis, and the brown-like adipocyte lineage in subcutaneous adipose tissue were also changed. All these alterations were corrected during the recovery phase, except for the hypoleptinemia that persisted despite the full recovery of fat mass. Conclusion This study strongly supports the separation-based anorexia protocol as a valuable model of long-term negative energy balance state that closely mimics various symptoms observed in anorexia nervosa, including metabolic adaptations. Interestingly, during a recovery phase, mice showed a high capacity to normalize these parameters with the exception of plasma leptin levels. It will be interesting therefore to explore further the central and peripheral effects of the uncorrected hypoleptinemia during recovery from separation-based anorexia.
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Affiliation(s)
- Sara Zgheib
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Mathieu Méquinion
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
| | - Stéphanie Lucas
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Damien Leterme
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Olfa Ghali
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Virginie Tolle
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Philippe Zizzari
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nicole Bellefontaine
- Université Lille Nord de France, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
| | - Isabelle Legroux-Gérot
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- Service de Rhumatologie, Hôpital Roger Salengro, CHU Lille, France
| | - Pierre Hardouin
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Odile Broux
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
| | - Odile Viltart
- Université Lille Nord de France, Boulogne sur Mer, France
- UMR INSERM 837, Développement et Plasticité du Cerveau Post-natal, Lille, France
- Université de Lille1, Villeneuve d’Ascq, France
| | - Christophe Chauveau
- Université Lille Nord de France, Boulogne sur Mer, France
- Physiopathologie des Maladies Osseuses Inflammatoires, Boulogne sur Mer, France
- * E-mail:
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