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Wulff BS, Kuhre RE, Selvaraj M, Rehfeld JF, Niss K, Fels JJ, Anna S, Raun K, Gerstenberg MK. Improved leptin sensitivity and increased soluble leptin receptor concentrations may underlie the additive effects of combining PYY [, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ] and exendin-4 on body weight lowering in diet-induced obese mice. Heliyon 2024; 10:e32009. [PMID: 39183855 PMCID: PMC11341243 DOI: 10.1016/j.heliyon.2024.e32009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 08/27/2024] Open
Abstract
Objective Co-treatment with long acting PYY and the GLP-1 receptor agonists has potential as an efficient obesity treatment. This study investigates whether the mechanisms behind additive reduction of food intake and weight loss depends on complementary effects in brain areas regulating food intake and if restoration of leptin sensitivity is involved. Methods Diet-induced obese (DIO) mice were co-treated with PYY(3-36) and exendin-4 (Ex4, GLP-1R agonist) for 14 days using minipumps. Leptin responsiveness was evaluated by measuring food intake and body weight after leptin injection, and gene expression profile was investigated in various of brain regions and liver. Results We show that weight loss associated with co-treatment of PYY(3-36) and Ex4 and Ex4 mono-treatment in DIO mice increased expression of several genes in area postrema (AP) known to be involved in appetite regulation and Cart, Pdyn, Bdnf and Klb were synergistically upregulated by the co-treatment. The upregulations were independent of weight loss, as shown by inclusion of a weight matched control. Moreover, PYY(3-36) and Ex4 co-treatment resulted in synergistically upregulated plasma concentrations of soluble leptin receptor (SLR) and improved sensitivity to exogenous leptin demonstrated by food intake lowering. Conclusion The study results suggest that synergistic upregulation of appetite-regulating genes in AP and improved leptin sensitivity are important mediators for the additive weight loss resulting from PYY and Ex4 co-treatment.
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Affiliation(s)
| | | | - Madhan Selvaraj
- Translational Research, Global Translation, Novo Nordisk A/S, 2760 Måløv, Denmark
| | - Jens F. Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Kristoffer Niss
- Biomarker Discovery, R&ED Digital Science and Innovation, Novo Nordisk A/S, 2760 Måløv, Denmark
| | - Johannes J. Fels
- Research Bioanalysis, Global Research Technologies, Novo Nordisk A/S, 2760 Måløv, Denmark
| | - Secher Anna
- Global Drug Discovery, Novo Nordisk A/S, 2760, Måløv, Denmark
| | - Kirsten Raun
- Global Drug Discovery, Novo Nordisk A/S, 2760, Måløv, Denmark
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LA Padula D, Zavaglia L, Hamad T, Nocito MC, Aquila S, Avena P, Rago V. Leptin effects: focusing on the relationship between obesity and male infertility. Minerva Endocrinol (Torino) 2024; 49:100-110. [PMID: 36251021 DOI: 10.23736/s2724-6507.22.03901-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The human male infertility has several causes interconnected to improper lifestyles such as smoking, sedentarism, environmental factors, toxins accumulation and energy imbalances. All these factors contribute to the obesity accompanied metabolic syndrome and hormonal alterations in the leptin-ghrelin axis. The leptin (Lep) has many pleiotropic effects in several biological systems, directly on the peripheral tissues or through the central nervous system. Many studies suggest that Lep is a key player in gonadal functions beside its documented role in reproductive regulation; however, further investigations are still necessary to elucidate all the molecular pathways involved in these mechanisms. Keeping into account that increased Lep levels in obese men are positively correlated with altered sperm parameters and testicular oxidative stress, evidence refers to Lep as a potential link between obesity and male infertility. This review represents an updated version on the concept of the Lep roles in mediating the male reproductive functions in obese patients.
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Affiliation(s)
- Davide LA Padula
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Lucia Zavaglia
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Tarig Hamad
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Marta C Nocito
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Saveria Aquila
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Paola Avena
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Vittoria Rago
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy -
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3
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Tsirigotaki A, Dansercoer A, Verschueren KHG, Marković I, Pollmann C, Hafer M, Felix J, Birck C, Van Putte W, Catteeuw D, Tavernier J, Fernando Bazan J, Piehler J, Savvides SN, Verstraete K. Mechanism of receptor assembly via the pleiotropic adipokine Leptin. Nat Struct Mol Biol 2023; 30:551-563. [PMID: 36959263 DOI: 10.1038/s41594-023-00941-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/06/2023] [Indexed: 03/25/2023]
Abstract
The adipokine Leptin activates its receptor LEP-R in the hypothalamus to regulate body weight and exerts additional pleiotropic functions in immunity, fertility and cancer. However, the structure and mechanism of Leptin-mediated LEP-R assemblies has remained unclear. Intriguingly, the signaling-competent isoform of LEP-R is only lowly abundant amid several inactive short LEP-R isoforms contributing to a mechanistic conundrum. Here we show by X-ray crystallography and cryo-EM that, in contrast to long-standing paradigms, Leptin induces type I cytokine receptor assemblies featuring 3:3 stoichiometry and demonstrate such Leptin-induced trimerization of LEP-R on living cells via single-molecule microscopy. In mediating these assemblies, Leptin undergoes drastic restructuring that activates its site III for binding to the Ig domain of an adjacent LEP-R. These interactions are abolished by mutations linked to obesity. Collectively, our study provides the structural and mechanistic framework for how evolutionarily conserved Leptin:LEP-R assemblies with 3:3 stoichiometry can engage distinct LEP-R isoforms to achieve signaling.
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Affiliation(s)
- Alexandra Tsirigotaki
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Ann Dansercoer
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Koen H G Verschueren
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Iva Marković
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Christoph Pollmann
- Department of Biology/Chemistry and Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany
| | - Maximillian Hafer
- Department of Biology/Chemistry and Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany
| | - Jan Felix
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Catherine Birck
- Integrated Structural Biology Platform, Centre for Integrative Biology (CBI), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U1258, University of Strasbourg, Illkirch, France
| | | | - Dominiek Catteeuw
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Jan Tavernier
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Orionis Biosciences, Ghent, Belgium
| | - J Fernando Bazan
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
- ħ Bioconsulting llc, Stillwater, MN, USA
| | - Jacob Piehler
- Department of Biology/Chemistry and Center for Cellular Nanoanalytics, Osnabrück University, Osnabrück, Germany
| | - Savvas N Savvides
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium.
| | - Kenneth Verstraete
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium.
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Babaei P, Hoseini R. Exercise training modulates adipokine dysregulations in metabolic syndrome. SPORTS MEDICINE AND HEALTH SCIENCE 2022; 4:18-28. [PMID: 35782776 PMCID: PMC9219261 DOI: 10.1016/j.smhs.2022.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/01/2022] [Accepted: 01/07/2022] [Indexed: 12/16/2022] Open
Abstract
Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.
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Affiliation(s)
- Parvin Babaei
- Cellular & Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Rastegar Hoseini
- Department of Sports Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
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5
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The role of leptin and low testosterone in obesity. Int J Impot Res 2022; 34:704-713. [DOI: 10.1038/s41443-022-00534-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 01/21/2022] [Indexed: 12/29/2022]
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Berger C, Heyne HO, Heiland T, Dommel S, Höfling C, Guiu-Jurado E, Roßner S, Dannemann M, Kelso J, Kovacs P, Blüher M, Klöting N. A novel compound heterozygous leptin receptor mutation causes more severe obesity than in Lepr db/db mice. J Lipid Res 2021; 62:100105. [PMID: 34390703 PMCID: PMC8450258 DOI: 10.1016/j.jlr.2021.100105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/04/2023] Open
Abstract
The leptin receptor (Lepr) pathway is important for food intake regulation, energy expenditure, and body weight. Mutations in leptin and the Lepr have been shown to cause early-onset severe obesity in mice and humans. In studies with C57BL/6NCrl mice, we found a mouse with extreme obesity. To identify a putative spontaneous new form of monogenic obesity, we performed backcross studies with this mouse followed by a quantitative trait locus (QTL) analysis and sequencing of the selected chromosomal QTL region. We thereby identified a novel Lepr mutation (C57BL/6N-LeprL536Hfs*6-1NKB), which is located at chromosome 4, exon 11 within the CRH2-leptin-binding site. Compared with C57BL/6N mice, LeprL536Hfs*6 develop early onset obesity and their body weight exceeds that of Leprdb/db mice at an age of 30 weeks. Similar to Leprdb/db mice, the LeprL536Hfs*6 model is characterized by hyperphagia, obesity, lower energy expenditure and activity, hyperglycemia, and hyperinsulinemia compared with C57BL/6N mice. Crossing Leprdb/wt with LeprL536Hfs*6/wt mice results in compound heterozygous LeprL536Hfs*6/db mice, which develop even higher body weight and fat mass than both homozygous Leprdb/db and LeprL536Hfs*6 mice. Compound heterozygous Lepr deficiency affecting functionally different regions of the Lepr causes more severe obesity than the parental homozygous mutations.
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Affiliation(s)
- Claudia Berger
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Henrike O Heyne
- Medical Department, Institute for Human Genetics, University of Leipzig Medical Center, Leipzig, Germany; Institute for Molecular Medicine Finland: FIMM, Helsinki, Finland; Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Tina Heiland
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Sebastian Dommel
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Corinna Höfling
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Esther Guiu-Jurado
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany
| | - Steffen Roßner
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Michael Dannemann
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Peter Kovacs
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany
| | - Matthias Blüher
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany
| | - Nora Klöting
- Medical Department III, Endocrinology, Nephrology, Rheumatology, CRC1052, University of Leipzig Medical Center, Leipzig, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, Leipzig, Germany.
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7
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Bakshi A, Singh R, Rai U. Trajectory of leptin and leptin receptor in vertebrates: Structure, function and their regulation. Comp Biochem Physiol B Biochem Mol Biol 2021; 257:110652. [PMID: 34343670 DOI: 10.1016/j.cbpb.2021.110652] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 06/23/2021] [Accepted: 07/29/2021] [Indexed: 12/11/2022]
Abstract
The present review provides a comparative insight into structure, function and control of leptin system in fishes, herptiles, birds and mammals. In general, leptin acts as an anorexigenic hormone since its administration results in decrease of food intake in vertebrates. Nonetheless, functional paradox arises in fishes from contradictory observations on level of leptin during fasting and re-feeding. In addition, leptin is shown to modulate metabolic functions in fishes, reptiles, birds and mammals. Leptin also regulates reproductive and immune functions though more studies are warranted in non-mammalian vertebrates. The expression of leptin and its receptor is influenced by numerous factors including sex steroids, stress and stress-induced catecholamines and glucocorticoids though their effect in non-mammalian vertebrates is hard to be generalized due to limited studies.
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Affiliation(s)
- Amrita Bakshi
- Department of Zoology, University of Delhi, Delhi 110007, India
| | - Rajeev Singh
- Satyawati College, University of Delhi, Delhi 110052, India
| | - Umesh Rai
- Department of Zoology, University of Delhi, Delhi 110007, India.
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8
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Pereira S, Cline DL, Glavas MM, Covey SD, Kieffer TJ. Tissue-Specific Effects of Leptin on Glucose and Lipid Metabolism. Endocr Rev 2021; 42:1-28. [PMID: 33150398 PMCID: PMC7846142 DOI: 10.1210/endrev/bnaa027] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 12/18/2022]
Abstract
The discovery of leptin was intrinsically associated with its ability to regulate body weight. However, the effects of leptin are more far-reaching and include profound glucose-lowering and anti-lipogenic effects, independent of leptin's regulation of body weight. Regulation of glucose metabolism by leptin is mediated both centrally and via peripheral tissues and is influenced by the activation status of insulin signaling pathways. Ectopic fat accumulation is diminished by both central and peripheral leptin, an effect that is beneficial in obesity-associated disorders. The magnitude of leptin action depends upon the tissue, sex, and context being examined. Peripheral tissues that are of particular relevance include the endocrine pancreas, liver, skeletal muscle, adipose tissues, immune cells, and the cardiovascular system. As a result of its potent metabolic activity, leptin is used to control hyperglycemia in patients with lipodystrophy and is being explored as an adjunct to insulin in patients with type 1 diabetes. To fully understand the role of leptin in physiology and to maximize its therapeutic potential, the mechanisms of leptin action in these tissues needs to be further explored.
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Affiliation(s)
- Sandra Pereira
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Daemon L Cline
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Maria M Glavas
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Scott D Covey
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada.,Department of Surgery, University of British Columbia, Vancouver, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
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9
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Quantile-specific heritability of sibling leptin concentrations and its implications for gene-environment interactions. Sci Rep 2020; 10:22152. [PMID: 33335207 PMCID: PMC7747738 DOI: 10.1038/s41598-020-79116-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022] Open
Abstract
"Quantile-dependent expressivity" occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., leptin) is high or low relative to its distribution. Leptin concentrations are strongly related to adiposity, whose heritability is quantile dependent. Whether inheritance of leptin concentrations is quantile dependent, and whether this explains the greater heritability in women than men in accordance with their greater adiposity, and explains other gene-environment interactions, remains to be determined. Therefore, leptin and leptin receptor concentrations from 3068 siblings in 1133 sibships from the Framingham Heart Study Third Generation Cohort were analyzed. Free leptin index (FLI) was calculated as the ratio of leptin to soluble leptin receptor concentrations. Full-sib (βFS) regression slopes were robustly estimated by quantile regression with nonparametric significance assigned from 1000 bootstrap samples. The analyses showed βFS increased significantly with increasing percentiles of the offspring's age- and sex-adjusted leptin distribution (Plinear = 0.0001), which was accelerated at the higher concentrations (Pquadratic = 0.0003). βFS at the 90th percentile (0.418 ± 0.066) was 4.7-fold greater than at the 10th percentile (0.089 ± 0.032, Pdifference = 3.6 × 10-6). Consistent with quantile-dependent expressivity, the βFS was greater in female sibs, which was attributable to their higher leptin concentrations. Reported gene-environment interactions involving adiposity and LEP, LEPR, MnSOD, PPARγ, PPARγ2, and IRS-1 polymorphisms were consistent with quantile-dependent expressivity of leptin concentrations. βFS for leptin receptor concentrations and free leptin index also increased significantly with increasing percentiles of their distributions (Plinear = 0.04 and Plinear = 8.5 × 10-6, respectively). In conclusion, inherited genetic and shared environmental effects on leptin concentrations were quantile dependent, which likely explains male-female differences in heritability and some gene-environment interactions.
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10
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Drori A, Gammal A, Azar S, Hinden L, Hadar R, Wesley D, Nemirovski A, Szanda G, Salton M, Tirosh B, Tam J. CB 1R regulates soluble leptin receptor levels via CHOP, contributing to hepatic leptin resistance. eLife 2020; 9:60771. [PMID: 33210603 PMCID: PMC7728447 DOI: 10.7554/elife.60771] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022] Open
Abstract
The soluble isoform of leptin receptor (sOb-R), secreted by the liver, regulates leptin bioavailability and bioactivity. Its reduced levels in diet-induced obesity (DIO) contribute to hyperleptinemia and leptin resistance, effects that are regulated by the endocannabinoid (eCB)/CB1R system. Here we show that pharmacological activation/blockade and genetic overexpression/deletion of hepatic CB1R modulates sOb-R levels and hepatic leptin resistance. Interestingly, peripheral CB1R blockade failed to reverse DIO-induced reduction of sOb-R levels, increased fat mass and dyslipidemia, and hepatic steatosis in mice lacking C/EBP homologous protein (CHOP), whereas direct activation of CB1R in wild-type hepatocytes reduced sOb-R levels in a CHOP-dependent manner. Moreover, CHOP stimulation increased sOb-R expression and release via a direct regulation of its promoter, while CHOP deletion reduced leptin sensitivity. Our findings highlight a novel molecular aspect by which the hepatic eCB/CB1R system is involved in the development of hepatic leptin resistance and in the regulation of sOb-R levels via CHOP. When the human body has stored enough energy from food, it releases a hormone called leptin that travels to the brain and stops feelings of hunger. This hormone moves through the bloodstream and can affect other organs, such as the liver, which also help control our body’s energy levels. Most people with obesity have very high levels of leptin in their blood, but are resistant to its effects and will therefore continue to feel hungry despite having stored enough energy. One of the proteins that controls the levels of leptin is a receptor called sOb-R, which is released by the liver and binds to leptin as it travels in the blood. Individuals with high levels of this receptor often have less free leptin in their bloodstream and a lower body weight. Another protein that helps the body to regulate its energy levels is the cannabinoid-1 receptor, or CB1R for short. In people with obesity, this receptor is overactive and has been shown to contribute to leptin resistance, which is when the brain becomes less receptive to leptin. Previous work in mice showed that blocking CB1R reduced the levels of leptin and allowed mice to react to this hormone normally again, but it remained unclear whether CB1R affects how other organs, such as the liver, respond to leptin. To answer this question, Drori et al. blocked the CB1R receptor in the liver of mice eating a high-fat diet, either by using a drug or by deleting the gene that codes for this protein. This caused mice to have higher levels of sOb-R circulating in their bloodstream. Further experiments showed that this change in sOb-R was caused by the levels of a protein called CHOP increasing in the liver when CB1R was blocked. Drori et al. found that inhibiting CB1R caused these obese mice to lose weight and have healthier, less fatty livers as a result of their livers no longer being resistant to the effects of leptin. Scientists, doctors and pharmaceutical companies are trying to develop new strategies to combat obesity. The results from these experiments suggest that blocking CB1R in the liver could allow this organ to react to leptin appropriately again. Drugs blocking CB1R, including the one used in this study, will be tested in clinical trials and could provide a new approach for treating obesity.
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Affiliation(s)
- Adi Drori
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Asaad Gammal
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shahar Azar
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Liad Hinden
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rivka Hadar
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daniel Wesley
- Laboratory of Physiological Studies, National Institute on Alcohol Abuse & Alcoholism, Bethesda, United States
| | - Alina Nemirovski
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gergő Szanda
- MTA-SE Laboratory of Molecular Physiology, Department of Physiology, Semmelweis University, Budapest, Hungary
| | - Maayan Salton
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Boaz Tirosh
- The Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Joseph Tam
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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11
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Sergi D, Williams LM. Potential relationship between dietary long-chain saturated fatty acids and hypothalamic dysfunction in obesity. Nutr Rev 2020; 78:261-277. [PMID: 31532491 DOI: 10.1093/nutrit/nuz056] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Diet-induced hypothalamic inflammation, which leads to hypothalamic dysfunction and a loss of regulation of energy balance, is emerging as a potential driver of obesity. Excessive intake of long-chain saturated fatty acids is held to be the causative dietary component in hypothalamic inflammation. This review summarizes current evidence on the role of long-chain saturated fatty acids in promoting hypothalamic inflammation and the related induction of central insulin and leptin insensitivity. Particularly, the present review focuses on the molecular mechanisms linking long-chain saturated fatty acids and hypothalamic inflammation, emphasizing the metabolic fate of fatty acids and the resulting lipotoxicity, which is a key driver of hypothalamic dysfunction. In conclusion, long-chain saturated fatty acids are key nutrients that promote hypothalamic inflammation and dysfunction by fostering the build-up of lipotoxic lipid species, such as ceramide. Furthermore, when long-chain saturated fatty acids are consumed in combination with high levels of refined carbohydrates, the proinflammatory effects are exacerbated via a mechanism that relies on the formation of advanced glycation end products.
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Affiliation(s)
- Domenico Sergi
- Nutrition and Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, South Australia, Australia
| | - Lynda M Williams
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
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12
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Keinicke H, Sun G, Mentzel CMJ, Fredholm M, John LM, Andersen B, Raun K, Kjaergaard M. FGF21 regulates hepatic metabolic pathways to improve steatosis and inflammation. Endocr Connect 2020; 9:755-768. [PMID: 32688339 PMCID: PMC7424338 DOI: 10.1530/ec-20-0152] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 07/19/2020] [Indexed: 12/11/2022]
Abstract
The prevalence of non-alcoholic fatty liver disease (NAFLD) has increased dramatically worldwide and, subsequently, also the risk of developing non-alcoholic steatohepatitis (NASH), hepatic fibrosis, cirrhosis and cancer. Today, weight loss is the only available treatment, but administration of fibroblast growth factor 21 (FGF21) analogues have, in addition to weight loss, shown improvements on liver metabolic health but the mechanisms behind are not entirely clear. The aim of this study was to investigate the hepatic metabolic profile in response to FGF21 treatment. Diet-induced obese (DIO) mice were treated with s.c. administration of FGF21 or subjected to caloric restriction by switching from high fat diet (HFD) to chow to induce 20% weight loss and changes were compared to vehicle dosed DIO mice. Cumulative caloric intake was reduced by chow, while no differences were observed between FGF21 and vehicle dosed mice. The body weight loss in both treatment groups was associated with reduced body fat mass and hepatic triglycerides (TG), while hepatic cholesterol was slightly decreased by chow. Liver glycogen was decreased by FGF21 and increased by chow. The hepatic gene expression profiles suggest that FGF21 increased uptake of fatty acids and lipoproteins, channeled TGs toward the production of cholesterol and bile acid, reduced lipogenesis and increased hepatic glucose output. Furthermore, FGF21 appeared to reduce inflammation and regulate hepatic leptin receptor-a expression. In conclusion, FGF21 affected several metabolic pathways to reduce hepatic steatosis and improve hepatic health and markedly more genes than diet restriction (61 vs 16 out of 89 investigated genes).
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Affiliation(s)
- Helle Keinicke
- Insulin and Device Trial Operations, Novo Nordisk A/S, Søborg, Denmark
| | - Gao Sun
- Pharmacology and Histopathology, Novo Nordisk A/S, China
| | - Caroline M Junker Mentzel
- Department of Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Merete Fredholm
- Department of Veterinary Clinical and Animal Science, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Linu Mary John
- Global Obesity and Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
| | - Birgitte Andersen
- Global Obesity and Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
| | - Kirsten Raun
- Global Obesity and Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
| | - Marina Kjaergaard
- Global Obesity and Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
- Correspondence should be addressed to M Kjaergaard:
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The association of anthropometric parameters with markers of insulin and leptin secretion and resistance in type 2 diabetes mellitus. REV ROMANA MED LAB 2020. [DOI: 10.2478/rrlm-2020-0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Abstract
Aim: We evaluated the association between anthropometric parameters and markers of insulin and leptin secretion/resistance in patients with type 2 diabetes mellitus (T2DM).
Material and methods: This post-hoc data analysis from a cross-sectional study included 176 T2DM patients. Laboratory tests (serum leptin, soluble form of leptin receptor (sObR), C peptide, glycemic and lipid parameters) and anthropometric parameters were obtained, adiposity indexes (including body adiposity index (BAI), visceral adiposity index (VAI)), indicators of insulin resistance, β-cell function, and leptin resistance (Free Leptin Index, FLI) were calculated.
Results: The body mass index (BMI), diabetes duration, VAI and leptin correlated independently with HOMA-IR, while BMI, diabetes duration and HbA1c with HOMA-B. The total body fat mass (TBFM), C peptide, diabetes duration, BMI and BAI correlated with leptin concentrations, while the first three with FLI. VAI was an indicator of insulin resistance (β=0.166, p=0.003), while BAI of leptin secretion (β=0.260, p=0.010). TBFM strongly associated with leptin resistance and secretion (β=0.037, r=0.688, p<0.0001, and β=0.521, r=0.667, p<0.0001), and BMI correlated weakly with insulin secretion and resistance. While insulin and leptin secretion increased progressively with BMI, leptin and insulin resistance became significant only in case of obesity. The sObR was significantly associated with C peptide concentrations (β=-0.032; p=0.044), but not with HOMA-B or -IR. A strong positive correlation between the C peptide/leptin ratio and non-fat mass /TBFM ratio was noted (r=0.62 [0.52, 0.71], p<0.0001).
Conclusions: Parameters of peripheral adiposity correlated better with markers of leptin system, and those of visceral adiposity with markers of insulin secretion/resistance. The sObR correlated independently and negatively with C peptide.
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Poetsch MS, Strano A, Guan K. Role of Leptin in Cardiovascular Diseases. Front Endocrinol (Lausanne) 2020; 11:354. [PMID: 32655492 PMCID: PMC7325922 DOI: 10.3389/fendo.2020.00354] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/06/2020] [Indexed: 01/01/2023] Open
Abstract
The adipocyte-derived adipokine leptin exerts pleiotropic effects, which are essential for the regulation of energy balance and cell metabolism, for controlling inflammatory and immune responses, and for the maintenance of homeostasis of the cardiovascular system. Leptin resistance in obese or type 2 diabetes mellitus (T2DM) patients is defined as a decrease in tissue response to leptin. In the cardiovascular system, leptin resistance exhibits the adverse effect on the heart's response to stress conditions and promoting cardiac remodeling due to impaired cardiac metabolism, increased fibrosis, vascular dysfunction, and enhanced inflammation. Leptin resistance or leptin signaling deficiency results in the risk increase of cardiac dysfunction and heart failure, which is a leading cause of obesity- and T2DM-related morbidity and mortality. Animal studies using leptin- and leptin receptor- (Lepr) deficient rodents have provided many useful insights into the underlying molecular and pathophysiological mechanisms of obese- and T2DM-associated metabolic and cardiovascular diseases. However, none of the animal models used so far can fully recapitulate the phenotypes of patients with obese or T2DM. Therefore, the role of leptin in the human cardiovascular system, and whether leptin affects cardiac function directly or acts through a leptin-regulated neurohumoral pathway, remain elusive. As the prevalence of obesity and diabetes is continuously increasing, strategies are needed to develop and apply human cell-based models to better understand the precise role of leptin directly in different cardiac cell types and to overcome the existing translational barriers. The purpose of this review is to discuss the mechanisms associated with leptin signaling deficiency or leptin resistance in the development of metabolic and cardiovascular diseases. We analyzed and comprehensively addressed substantial findings in pathophysiological mechanisms in commonly used leptin- or Lepr-deficient rodent models and highlighted the differences between rodents and humans. This may open up new strategies to develop directly and reliably applicable models, which resemble the human pathophysiology in order to advance health care management of obesity- and T2DM-related cardiovascular complications.
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16
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Xu L, Li H, Zhou G, Lu W, Yang R, Liu H, Yang G. DNA-binding activity of STAT3 increased in hypothalamus of DIO mice; the reduction of STAT3 phosphorylation may facilitate leptin signaling. Biochem Biophys Res Commun 2018; 505:229-235. [PMID: 30243722 DOI: 10.1016/j.bbrc.2018.09.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 09/09/2018] [Indexed: 11/30/2022]
Abstract
Leptin-mediated DNA-binding activity of STAT3 in hypothalamus plays crucial roles in the maintenance of energy homeostasis in lean mice; however its effects still remains unclear in case of leptin resistance in mice with diet induced obesity (DIO). In this study significant elevation of both basal and exogenously leptin-treated DNA-binding activity of STAT3 was detected using EMSA in the hypothalamus of male C57BL/6J mice fed high-fat diet for 10 wks, in concomitant with hyperleptinemia, high body weight, high fat mass, and hyperphagia as well as decreased POMC expression. The studies in vitro showed that both DNA binding activity and the proximal SBE of POMC promoter was essential to leptin-mediated POMC expression. However, the diminution of STAT3 phosphorylation, achieved by S3I-201 or a FoxO1 mutant, facilitated leptin-mediated POMC expression. The findings here demonstrated excess STAT3 activity negatively regulated POMC expression in hypothalamus of DIO mice, and suggested the limitation of STAT3 activity may promote leptin signaling.
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Affiliation(s)
- Liang Xu
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Hao Li
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Guoli Zhou
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Wanping Lu
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Ran Yang
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Huimin Liu
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China
| | - Guoqing Yang
- Laboratory of Animal Gene Engineering, College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002, People's Republic of China; Touchstone Center for Diabetes Research, Department of Physiology, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, 75390-8854, USA.
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17
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Mazor R, Friedmann-Morvinski D, Alsaigh T, Kleifeld O, Kistler EB, Rousso-Noori L, Huang C, Li JB, Verma IM, Schmid-Schönbein GW. Cleavage of the leptin receptor by matrix metalloproteinase-2 promotes leptin resistance and obesity in mice. Sci Transl Med 2018; 10:eaah6324. [PMID: 30135249 PMCID: PMC9678493 DOI: 10.1126/scitranslmed.aah6324] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 05/01/2017] [Accepted: 03/22/2018] [Indexed: 08/08/2023]
Abstract
Obesity and related morbidities pose a major health threat. Obesity is associated with increased blood concentrations of the anorexigenic hormone leptin; however, obese individuals are resistant to its anorexigenic effects. We examined the phenomenon of reduced leptin signaling in a high-fat diet-induced obesity model in mice. Obesity promoted matrix metalloproteinase-2 (Mmp-2) activation in the hypothalamus, which cleaved the leptin receptor's extracellular domain and impaired leptin-mediated signaling. Deletion of Mmp-2 restored leptin receptor expression and reduced circulating leptin concentrations in obese mice. Lentiviral delivery of short hairpin RNA to silence Mmp-2 in the hypothalamus of wild-type mice prevented leptin receptor cleavage and reduced fat accumulation. In contrast, lentiviral delivery of Mmp-2 in the hypothalamus of Mmp-2-/- mice promoted leptin receptor cleavage and higher body weight. In a genetic mouse model of obesity, transduction of cleavage-resistant leptin receptor in the hypothalamus reduced the rate of weight gain compared to uninfected mice or mice infected with the wild-type receptor. Immunofluorescence analysis showed that astrocytes and agouti-related peptide neurons were responsible for Mmp-2 secretion in mice fed a high-fat diet. These results suggest a mechanism for leptin resistance through activation of Mmp-2 and subsequent cleavage of the extracellular domain of the leptin receptor.
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Affiliation(s)
- Rafi Mazor
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Dinorah Friedmann-Morvinski
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tom Alsaigh
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Oded Kleifeld
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Erik B Kistler
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA 92093, USA
- Department of Anesthesiology and Critical Care, University of California, San Diego, La Jolla, CA 92093, USA
| | - Liat Rousso-Noori
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Cheng Huang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Joyce B Li
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Inder M Verma
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Geert W Schmid-Schönbein
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA
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18
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Wauman J, Tavernier J. The intracellular domain of the leptin receptor prevents mitochondrial depolarization and mitophagy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1312-1325. [PMID: 29932990 DOI: 10.1016/j.bbamcr.2018.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/31/2018] [Accepted: 06/17/2018] [Indexed: 11/27/2022]
Abstract
Hypothalamic leptin receptor (LR) signaling regulates body weight by balancing food intake and energy expenditure. It is well established that the human LR undergoes ectodomain shedding, but little is known about the fate of the remaining cytosolic domain. This study demonstrates that regulated intramembrane proteolysis (RIP) releases the LR intracellular domain (LR ICD), which translocates to the mitochondria where it binds to SOCS6. This LR ICD-SOCS6 interaction stabilizes both proteins on the mitochondrial outer membrane and requires a functional BC box in SOCS6 for mitochondrial association and a central motif in the LR ICD for SOCS6 binding. The LR ICD prevents CCCP-induced mitochondrial depolarization and mitophagy as shown by lowered Parkin translocation and p62 accumulation. Strict regulation of mitochondrial dynamics in the hypothalamus is known to be essential for body weight homeostasis. This is the first study showing that the LR can directly modulate mitochondrial biology.
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Affiliation(s)
- Joris Wauman
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Jan Tavernier
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium..
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19
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Sudhakar M, Silambanan S, Chandran AS, Prabhakaran AA, Ramakrishnan R. C-Reactive Protein (CRP) and Leptin Receptor in Obesity: Binding of Monomeric CRP to Leptin Receptor. Front Immunol 2018; 9:1167. [PMID: 29910808 PMCID: PMC5992430 DOI: 10.3389/fimmu.2018.01167] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 05/09/2018] [Indexed: 02/04/2023] Open
Abstract
While leptin deficiency or dysfunction leads to morbid obesity, obese subjects are characterized paradoxically by hyperleptinemia indicating lack of response to leptin. C-reactive protein (CRP) has been suggested to be a key plasma protein that could bind to leptin. To examine whether CRP interferes with leptin action, mediated through its cell surface receptor, docking studies of CRP with the extracellular domain of the leptin receptor were done employing bioinformatics tools. Monomeric CRP docked with better Z-rank score and more non-bond interactions than pentameric CRP at the CRH2–FNIII domain proximal to the cell membrane, distinct from the leptin-docking site. Interaction of CRP with leptin receptor was validated by solid phase binding assay and co-immunoprecipitation of CRP and soluble leptin receptor (sOb R) from human plasma. Analysis of the serum levels of leptin, CRP, and sOb R by ELISA showed that CRP levels were significantly elevated (p < 0.0001) in non-morbid obese subjects (n = 42) compared to lean subjects (n = 32) and correlated positively with body mass index (BMI) (r = 0.74, p < 0.0001) and leptin (r = 0.8, p < 0.0001); levels of sOb R were significantly low in obese subjects (p < 0.001) and showed a negative correlation with BMI (r = −0.26, p < 0.05) and leptin (r = −0.23, p < 0.05) indicating a minimal role for sOb R in sequestering leptin.
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Affiliation(s)
- Manu Sudhakar
- Department of Biochemistry, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India
| | - Santhi Silambanan
- Department of Biochemistry, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India
| | - Abhinand S Chandran
- Department of Computational Biology and Bioinformatics, University of Kerala, Thiruvananthapuram, Kerala, India
| | - Athira A Prabhakaran
- Department of Computational Biology and Bioinformatics, University of Kerala, Thiruvananthapuram, Kerala, India
| | - Ramya Ramakrishnan
- Department of Surgery, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India
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20
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Sommer C, Lee S, Gulseth HL, Jensen J, Drevon CA, Birkeland KI. Soluble Leptin Receptor Predicts Insulin Sensitivity and Correlates With Upregulation of Metabolic Pathways in Men. J Clin Endocrinol Metab 2018; 103:1024-1032. [PMID: 29300960 DOI: 10.1210/jc.2017-02126] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
CONTEXT Plasma soluble leptin receptor (sOb-R) seems protective of gestational and type 2 diabetes in observational studies, but the mechanisms are unknown. sOb-R is formed by ectodomain shedding of membrane-bound leptin receptors (Ob-Rs), but its associations with messenger RNA (mRNA) expression are scarcely explored. OBJECTIVE To explore associations between plasma levels of sOb-R and (1) insulin sensitivity, (2) mRNA pathways in adipose tissue and skeletal muscle, and (3) mRNA of candidate genes for sOb-R generation in adipose tissue and skeletal muscle. DESIGN AND PARTICIPANTS The MyoGlu study included 26 sedentary, middle-aged men who underwent a 12-week intensive exercise intervention. We measured plasma sOb-R with enzyme-linked immunosorbent assay, insulin sensitivity with a hyperinsulinemic euglycemic clamp, and mRNA in skeletal muscle and adipose tissue with high-throughput sequencing. RESULTS Baseline plasma sOb-R was strongly associated with baseline glucose infusion rate (GIR) [β (95% confidence interval), 1.19 (0.57 to 1.82) mg/kg/min, P = 0.0006] and GIR improvement after the exercise intervention [0.58 (0.03 to 1.12) mg/kg/min, P = 0.039], also independently of covariates, including plasma leptin. In pathway analyses, high plasma sOb-R correlated with upregulation of metabolic pathways and downregulation of inflammatory pathways in both adipose tissue and skeletal muscle. In skeletal muscle, mRNA of LEPROT and LEPROTL1 (involved in Ob-R cell surface expression) and ADAM10 and ADAM17 (involved sOb-R-shedding) increased after the exercise intervention. CONCLUSIONS Higher plasma sOb-R was associated with improved GIR, upregulation of metabolic pathways, and downregulation of inflammatory pathways, which may be possible mechanisms for the seemingly protective effect of plasma sOb-R on subsequent risk of gestational and type 2 diabetes found in observational studies.
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Affiliation(s)
- Christine Sommer
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway
| | - Sindre Lee
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Hanne Løvdal Gulseth
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway
- Department of Noncommunicable Diseases, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Christian A Drevon
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Kåre Inge Birkeland
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway
- Department of Transplantation Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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21
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Zhang J, Gong M. Review of the role of leptin in the regulation of male reproductive function. Andrologia 2018; 50:e12965. [PMID: 29460468 DOI: 10.1111/and.12965] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2017] [Indexed: 12/13/2022] Open
Abstract
Since discovered in 1994, leptin has been thought to be a pleiotropic hormone that regulates food intake, controls energy balance in the body and influences multiple tissues in the body. Leptin plays an important mediating role in the regulation of neuroendocrine and can transmit the nutritional status signals to the reproductive-related central nervous system. Many studies have shown that leptin may play an important role in the control of reproductive function. Leptin can act on all levels of the hypothalamus-pituitary-gonadal (HPG) axis and may have local effects on the function of testis and spermatogenesis. Leptin is critical for puberty initiation and can also modulate testosterone synthesis by downregulating cAMP-dependent activation of steroidogenic genes expressions. Leptin is found to be higher in infertile men than in normal subjects. Yet, the exact role of leptin in the regulation of male reproductive function remains incomplete. The purpose of this review was to summarise the recent research about the biological effects of leptin on male reproductive system. In-depth study of leptin in reproductive system will help to reveal the pathogenesis of infertility and provide new treatment ideas for human assisted reproductive technology.
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Affiliation(s)
- J Zhang
- Department of Urology, Shanghai Pudong Hospital, Fudan University, Shanghai, China
| | - M Gong
- Department of Urology, Shanghai Pudong Hospital, Fudan University, Shanghai, China
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22
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Hubert A, Bochenek ML, Schütz E, Gogiraju R, Münzel T, Schäfer K. Selective Deletion of Leptin Signaling in Endothelial Cells Enhances Neointima Formation and Phenocopies the Vascular Effects of Diet-Induced Obesity in Mice. Arterioscler Thromb Vasc Biol 2017; 37:1683-1697. [DOI: 10.1161/atvbaha.117.309798] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 07/03/2017] [Indexed: 11/16/2022]
Affiliation(s)
- Astrid Hubert
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
| | - Magdalena L. Bochenek
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
| | - Eva Schütz
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
| | - Rajinikanth Gogiraju
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
| | - Thomas Münzel
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
| | - Katrin Schäfer
- From the Center for Cardiology, Cardiology I (A.H., M.L.B., E.S., R.G., T.M., K.S.) and Center for Thrombosis and Hemostasis (M.L.B.), University Medical Center Mainz, Germany
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Morioka T, Emoto M, Yamazaki Y, Kurajoh M, Motoyama K, Mori K, Fukumoto S, Shioi A, Shoji T, Inaba M. Plasma soluble leptin receptor levels are associated with pancreatic β-cell dysfunction in patients with type 2 diabetes. J Diabetes Investig 2017; 9:55-62. [PMID: 28294581 PMCID: PMC5754521 DOI: 10.1111/jdi.12657] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/06/2017] [Accepted: 03/08/2017] [Indexed: 12/20/2022] Open
Abstract
Aims/Introduction A soluble form of the leptin receptor (soluble Ob‐R) in the circulation regulates leptin's bioactivity, and is inversely associated with body adiposity and circulating leptin levels. However, no study has examined the clinical impact of soluble Ob‐R on glucose metabolism in diabetes. The present study aimed to investigate the association of plasma soluble Ob‐R levels with insulin resistance and pancreatic β‐cell function in patients with type 2 diabetes. Materials and Methods A total of 289 Japanese patients with type 2 diabetes were included in the present study. Fasting plasma soluble Ob‐R levels and plasma leptin levels were measured by enzyme‐linked immunosorbent assay. Insulin resistance and pancreatic β‐cell function were estimated by homeostasis model assessment of insulin resistance, homeostasis model assessment of β‐cell function and fasting C‐peptide index. Results The median plasma soluble Ob‐R level and plasma leptin level were 3.4 ng/mL and 23.6 ng/mL, respectively. Plasma soluble Ob‐R levels were negatively correlated with homeostasis model assessment of insulin resistance, homeostasis model assessment of β‐cell function and the C‐peptide index, whereas plasma leptin levels were positively correlated with each index in univariate analyses. Multivariate analyses including plasma soluble Ob‐R levels, plasma leptin levels and use of sulfonylureas, along with age, sex, body mass index and other covariates, showed that soluble Ob‐R levels were independently and negatively associated with homeostasis model assessment of β‐cell function and the C‐peptide index, but not significantly associated with homeostasis model assessment of insulin resistance. Conclusions Plasma soluble Ob‐R levels are independently associated with pancreatic β‐cell function, but not with insulin resistance, in patients with type 2 diabetes. The present study implicates the role of soluble Ob‐R in pancreatic β‐cell dysfunction in type 2 diabetes.
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Affiliation(s)
- Tomoaki Morioka
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masanori Emoto
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yuko Yamazaki
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masafumi Kurajoh
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Koka Motoyama
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Katsuhito Mori
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Shinya Fukumoto
- Premier Preventive Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Atsushi Shioi
- Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Tetsuo Shoji
- Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masaaki Inaba
- Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
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Wauman J, Zabeau L, Tavernier J. The Leptin Receptor Complex: Heavier Than Expected? Front Endocrinol (Lausanne) 2017; 8:30. [PMID: 28270795 PMCID: PMC5318964 DOI: 10.3389/fendo.2017.00030] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/01/2017] [Indexed: 12/31/2022] Open
Abstract
Under normal physiological conditions, leptin and the leptin receptor (ObR) regulate the body weight by balancing food intake and energy expenditure. However, this adipocyte-derived hormone also directs peripheral processes, including immunity, reproduction, and bone metabolism. Leptin, therefore, can act as a metabolic switch connecting the body's nutritional status to high energy consuming processes. We provide an extensive overview of current structural insights on the leptin-ObR interface and ObR activation, coupling to signaling pathways and their negative regulation, and leptin functioning under normal and pathophysiological conditions (obesity, autoimmunity, cancer, … ). We also discuss possible cross-talk with other receptor systems on the receptor (extracellular) and signaling cascade (intracellular) levels.
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Affiliation(s)
- Joris Wauman
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Lennart Zabeau
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Jan Tavernier
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
- *Correspondence: Jan Tavernier,
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Thon M, Hosoi T, Ozawa K. Possible Integrative Actions of Leptin and Insulin Signaling in the Hypothalamus Targeting Energy Homeostasis. Front Endocrinol (Lausanne) 2016; 7:138. [PMID: 27812350 PMCID: PMC5071376 DOI: 10.3389/fendo.2016.00138] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/07/2016] [Indexed: 12/17/2022] Open
Abstract
Obesity has emerged as one of the most burdensome conditions in modern society. In this context, understanding the mechanisms controlling food intake is critical. At present, the adipocyte-derived hormone leptin and the pancreatic β-cell-derived hormone insulin are considered the principal anorexigenic hormones. Although leptin and insulin signal transduction pathways are distinct, their regulation of body weight maintenance is concerted. Resistance to the central actions of leptin or insulin is linked to the emergence of obesity and diabetes mellitus. A growing body of evidence suggests a convergence of leptin and insulin intracellular signaling at the insulin-receptor-substrate-phosphatidylinositol-3-kinase level. Moreover, numerous factors mediating the pathophysiology of leptin resistance, a hallmark of obesity, such as endoplasmic reticulum stress, protein tyrosine phosphatase 1B, and suppressor of cytokine signaling 3 also contribute to insulin resistance. Recent studies have also indicated that insulin potentiates leptin-induced signaling. Thus, a greater understanding of the overlapping functions of leptin and insulin in the central nervous system is vital to understand the associated physiological and pathophysiological states. This mini-review focuses on the cross talk and integrative signaling of leptin and insulin in the regulation of energy homeostasis in the brain.
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Affiliation(s)
- Mina Thon
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Toru Hosoi
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Koichiro Ozawa
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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Tang X, Li J, Xiang W, Cui Y, Xie B, Wang X, Xu Z, Gan L. Metformin increases hepatic leptin receptor and decreases steatosis in mice. J Endocrinol 2016; 230:227-37. [PMID: 27288055 DOI: 10.1530/joe-16-0142] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 06/08/2016] [Indexed: 01/01/2023]
Abstract
In addition to the ascertained efficacy as antidiabetic drug, metformin is increasingly being used as weight-loss agent in obesity, and as insulin sensitizer in nonalcoholic fatty liver disease (NAFLD). However, the mechanisms underlying these effects are still incompletely understood. Emerging evidence suggest metformin as leptin sensitizer to mediate the weight-loss effect in the brain. In this study, we investigated effects of metformin on expression of leptin receptors in liver and kidney in mice. C57BL/6 mice were fed with chow diet (CD) or high-fat diet (HF) for 5months. Afterward, mice were treated with metformin (50mg/kg or 200mg/kg) for 15days. Metabolic parameters and hepatic gene expression were analyzed at the end of the treatment. We also tested the effects of metformin on plasma-soluble leptin receptor (sOB-R) levels in newly diagnosed type 2 diabetes mellitus (T2DM) patients, and assessed its effect on hepatosteatosis in mice. Results showed that metformin upregulates the expression of leptin receptors (OB-Ra, -Rb, -Rc, and -Rd) in liver but not kidney. The stimulation effect is dose-dependent in both chow and HF mice. Upregulation of OB-Rb, long signaling isoform, needs a relatively higher dose of metformin. This effect was paralleled by increased sOBR levels in mice and T2DM patients, and decreased hepatic triglyceride (TG) content and lipogenic gene expression, including sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthase (FAS) and acetyl-CoA carboxylase-1 (ACC-1). Taken together, these data identify hepatic leptin receptor as target gene being upregulated by metformin which may enhance leptin sensitivity in liver to alleviate steatosis.
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Affiliation(s)
- Xuemei Tang
- Department of Biochemistry and Molecular BiologyThird Military Medical University, Chongqing, China Department of Integrated MedicineXinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Jingwen Li
- Department of Biochemistry and Molecular BiologyThird Military Medical University, Chongqing, China Department of Integrated MedicineXinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Wei Xiang
- Department of Biochemistry and Molecular BiologyThird Military Medical University, Chongqing, China
| | - Ye Cui
- Department of Integrated MedicineXinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Bin Xie
- Department of Hepatobiliary SurgeryDaping Hospital & Institute of Surgery Research, Third Military Medical University, Chongqing, China
| | - Xiaodong Wang
- Institute of PathologySouthwest Hospital, Third Military Medical University, Chongqing, China
| | - Zihui Xu
- Department of Integrated MedicineXinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Lixia Gan
- Department of Biochemistry and Molecular BiologyThird Military Medical University, Chongqing, China
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Gómez-Bañuelos E, Navarro-Hernández RE, Corona-Meraz F, Madrigal-Ruíz PM, Martín-Marquez BT, Pizano-Martinez OE, Aguilar-Arreola J, Perez-Cruz PJ, Macias-Reyes H, Gonzalez-Lopez L, Gamez-Nava JI, Salazar-Páramo M, Vazquez-del Mercado M. Serum leptin and serum leptin/serum leptin receptor ratio imbalance in obese rheumatoid arthritis patients positive for anti-cyclic citrullinated peptide antibodies. Arthritis Res Ther 2015; 17:335. [PMID: 26589684 PMCID: PMC4654826 DOI: 10.1186/s13075-015-0850-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/04/2015] [Indexed: 01/23/2023] Open
Abstract
Introduction Leptin has a prominent role in the development and maintenance of acute and chronic inflammatory states such as rheumatoid arthritis (RA) and obesity. Nevertheless, the association of serum leptin (sLep) and soluble leptin receptor (sLepR) in RA pathogenesis has not been clarified. The purpose of this study was to evaluate the association of sLep, sLepR and leptin production indexes such as sLep/fat mass ratio with clinical activity and biomarkers and anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA compared with body mass index (BMI) matched control subjects. Methods We included 64 RA patients and 66 controls matched for age, gender and BMI. Subjects were evaluated for BMI, fat mass distribution, sLep, sLepR, sLep/fat mass ratio and sLepR/fat mass ratio. Patients were evaluated for clinical activity and anti-CCP antibodies. Results We found two or three fold increased sLep levels, sLep/sLepR ratio and sLep/fat mass ratio in obese anti-CCP positive RA patients vs. controls. Partial correlations showed that anti-CCP antibodies were correlated with sLep/fat mass ratio (partial r = 0.347, P = 0.033) after adjustment for age, subcutaneous adipose tissue and fat mass. Conclusions In preobese and obese RA patients there is and increased production of sLep according to anti-CCP positivity. This phenomenon suggests there is an additive effect of chronic inflammation resulting from RA and obesity in which leptin favors the humoral response against citrullinated proteins. In summary, the data observed in our study suggests sLep could be a surrogate marker of chronicity and humoral immunity in RA in the presence of obesity.
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Affiliation(s)
- Eduardo Gómez-Bañuelos
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Rosa Elena Navarro-Hernández
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Fernanda Corona-Meraz
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Perla Monserrat Madrigal-Ruíz
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Beatríz Teresita Martín-Marquez
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Oscar Enrique Pizano-Martinez
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Jorge Aguilar-Arreola
- Servicio de Reumatología, División de Medicina Interna, OPD Hospital Civil de Guadalajara, "Dr. Juan I. Menchaca", Salvador de Quevedo y Zubieta No. 750, Zip code 44100, Guadalajara, Jalisco, >México.
| | - Paul Jacob Perez-Cruz
- Servicio de Reumatología, División de Medicina Interna, OPD Hospital Civil de Guadalajara, "Dr. Juan I. Menchaca", Salvador de Quevedo y Zubieta No. 750, Zip code 44100, Guadalajara, Jalisco, >México.
| | - Hector Macias-Reyes
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México.
| | - Laura Gonzalez-Lopez
- Departamento de Medicina Interna-Reumatología, Hospital General Regional no.110, Instituto Mexicano del Seguro Social, Circunvalación Oblatos No. 2212, Colonia Oblatos, Zip code 44700, Guadalajara, Jalisco, México.
| | - Jorge Ivan Gamez-Nava
- Unidad Médica de Alta Especialidad, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Belisario Domínguez No. 1000, Independencia Oriente, Zip code 44340, Guadalajara, Jalisco, México.
| | - Mario Salazar-Páramo
- Unidad Médica de Alta Especialidad, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Belisario Domínguez No. 1000, Independencia Oriente, Zip code 44340, Guadalajara, Jalisco, México.
| | - Monica Vazquez-del Mercado
- Instituto de Investigación en Reumatología y del Sistema Musculoesquelético, CUCS, Universidad de Guadalajara, Sierra Mojada No. 950, Colonia Independencia, Zip code 44340, Guadalajara, Jalisco, México. .,Servicio de Reumatología, División de Medicina Interna, OPD Hospital Civil de Guadalajara, "Dr. Juan I. Menchaca", Salvador de Quevedo y Zubieta No. 750, Zip code 44100, Guadalajara, Jalisco, >México.
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Polymorphism of rs2767485 in Leptin Receptor Gene is Associated With the Occurrence of Adolescent Idiopathic Scoliosis. Spine (Phila Pa 1976) 2015; 40:1593-8. [PMID: 26731704 DOI: 10.1097/brs.0000000000001095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A genetic association study of leptin receptor (LEPR) gene with adolescent idiopathic scoliosis (AIS) in the Chinese Han population. OBJECTIVE To determine whether LEPR gene polymorphisms are associated with the predisposition and/or disease severity of AIS. SUMMARY OF BACKGROUND DATA Patients with AIS were reported to have lower body mass index (BMI), abnormal leptin bioavailability, and systemic lower bone mass, which implied that leptin/LEPR signaling pathway may be implicated in the etiology of AIS. Previous association study of the polymorphisms in leptin gene did not show significant differences between AIS cases and controls. However, no study has been done to investigate the relationship between genetic polymorphisms of the LEPR gene and susceptibility to AIS. METHODS 570 patients with AIS aged 10 to 18 years were enrolled, and 570 age-matched healthy subjects were recruited as controls. 6 single nucleotide polymorphisms (SNPs) (rs1137101, rs1137100, rs4655555, rs2767485, rs1751492, and rs8179183) of LEPR gene were selected. The polymorphisms were genotyped using the polymerase chain reaction (PCR)-based Invader assay. Case-control study was performed to define the contribution of the 6 SNPs to predisposition of AIS. 1-way analysis of variance (ANOVA) test was used to compare the mean Cobb angles and BMI among patients with different genotypes in case-only analyses. Statistical significance was set at P < 0.05. RESULTS Both the genotype and allele frequencies of SNP rs2767485 were significantly different between the patient with AIS and the control groups. No significant difference of allele frequency was noted in other 5 SNPs between the patients with AIS and the normal controls. Both the mean maximum Cobb angles and BMI of different genotype AIS groups were similar to each other for all the 6 SNPs (P > 0.05). CONCLUSION Polymorphism of rs2767485 in LEPR gene is associated with the occurrence of AIS, suggesting LEPR is a predisposition gene.
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Abstract
The adipokine leptin realizes signal transduction via four different leptin receptor (OB-R) isoforms. The amount of functionally active OB-R, however, is affected by constitutive shedding of the extracellular domain. The product of the cleavage process, the so-called soluble leptin receptor (sOB-R), is the main binding protein for leptin in human blood and modulates its bioavailability. Concentrations of sOB-R are differentially regulated in metabolic disorders, such as type 1 diabetes mellitus or obesity, and can, therefore, enhance or reduce leptin sensitivity. Lipotoxicity and apoptosis increase OB-R cleavage via ADAM10-dependent mechanisms. In contrast, although increased sOB-R concentrations seem to directly inhibit leptin effects, reduced amounts of sOB-R may reflect decreased membrane expression of OB-R. These findings, in part, explain alterations of leptin sensitivity that are associated with changes in serum sOB-R concentrations seen in metabolic disorders.
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Affiliation(s)
- Michael Schaab
- Institute of Laboratory Medicine Clinical Chemistry and Molecular Diagnostics, Leipzig, Germany.
| | - Juergen Kratzsch
- Institute of Laboratory Medicine Clinical Chemistry and Molecular Diagnostics, Leipzig, Germany
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Page-Wilson G, Meece K, White A, Rosenbaum M, Leibel RL, Smiley R, Wardlaw SL. Proopiomelanocortin, agouti-related protein, and leptin in human cerebrospinal fluid: correlations with body weight and adiposity. Am J Physiol Endocrinol Metab 2015; 309:E458-65. [PMID: 26152765 PMCID: PMC4556883 DOI: 10.1152/ajpendo.00206.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/01/2015] [Indexed: 11/22/2022]
Abstract
Leptin and its neuronal targets, which produce proopiomelanocortin (POMC) and agouti-related protein (AgRP), regulate energy balance. This study characterized leptin, POMC, and AgRP in the cerebrospinal fluid (CSF) of 47 healthy human subjects, 23 lean and 24 overweight/obese (OW/OB), as related to BMI, adiposity, plasma leptin, soluble leptin receptor (s-OB-R), and insulin. POMC was measured since the POMC prohormone is the predominant POMC peptide in CSF and correlates with hypothalamic POMC in rodents. Plasma AgRP was similarly characterized. CSF leptin was 83-fold lower than in plasma and correlated strongly with BMI, body fat, and insulin. The relative amount of leptin transported into CSF declined with increasing BMI, ranging from 4.5 to 0.52%, consistent with a saturable transport mechanism. CSF sOB-R was 78-fold lower than in plasma and correlated negatively with plasma and CSF leptin. CSF POMC was higher in lean vs. OW/OB subjects (P < 0.001) and correlated negatively with CSF leptin (r = -0.60, P < 0.001) and with plasma leptin, insulin, BMI, and adiposity. CSF AgRP was not different in lean vs. OW/OB; however, plasma AgRP was higher in lean subjects (P = 0.001) and correlated negatively with BMI, adiposity, leptin, insulin, and HOMA (P < 0.005). Thus, CSF measurements may provide useful biomarkers for brain leptin and POMC activity. The striking negative correlation between CSF leptin and POMC could be secondary to leptin resistance and/or neuronal changes associated with obesity but may also indicate that POMC plays a primary role in regulating body weight and adiposity. The role of plasma AgRP as a neuroendocrine biomarker deserves further study.
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Affiliation(s)
- Gabrielle Page-Wilson
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York
| | - Anne White
- Faculties of Life Sciences and Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Michael Rosenbaum
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Rudolph L Leibel
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Richard Smiley
- Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Sharon L Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York;
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Leptin: From structural insights to the design of antagonists. Life Sci 2015; 140:49-56. [PMID: 25998027 DOI: 10.1016/j.lfs.2015.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 12/20/2022]
Abstract
After its discovery in 1994, it soon became clear that leptin acts as an adipocyte-derived hormone with a central role in the control of body weight and energy homeostasis. However, a growing body of evidence has revealed that leptin is a pleiotropic cytokine with activities on many peripheral cell types. Inappropriate leptin signaling can promote autoimmunity, certain cardiovascular diseases, elevated blood pressure and cancer, which makes leptin and the leptin receptor interesting targets for antagonism. Profound insights in the leptin receptor (LR) activation mechanisms are a prerequisite for the rational design of these antagonists. In this review, we focus on the molecular mechanisms underlying leptin receptor activation and signaling. We also discuss the current strategies to interfere with leptin signaling and their therapeutic potential.
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Briffa JF, McAinch AJ, Romano T, Wlodek ME, Hryciw DH. Leptin in pregnancy and development: a contributor to adulthood disease? Am J Physiol Endocrinol Metab 2015; 308:E335-50. [PMID: 25516549 DOI: 10.1152/ajpendo.00312.2014] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Emerging research has highlighted the importance of leptin in fetal growth and development independent of its essential role in the maintenance of hunger and satiety through the modulation of neuropeptide Y and proopiomelanocortin neurons. Alterations in maternal-placental-fetal leptin exchange may modify the development of the fetus and contribute to the increased risk of developing disease in adulthood. In addition, leptin also plays an important role in reproductive functions, with plasma leptin concentrations rising in pregnant women, peaking during the third trimester. Elevated plasma leptin concentrations occur at the completion of organogenesis, and research in animal models has demonstrated that leptin is involved in the development and maturation of a number of organs, including the heart, brain, kidneys, and pancreas. Elevated maternal plasma leptin is associated with maternal obesity, and reduced fetal plasma leptin is correlated with intrauterine growth restriction. Alterations in plasma leptin during development may be associated with an increased risk of developing a number of adulthood diseases, including cardiovascular, metabolic, and renal diseases via altered fetal development and organogenesis. Importantly, research has shown that leptin antagonism after birth significantly reduces maturation of numerous organs. Conversely, restoration of the leptin deficiency after birth in growth-restricted animals restores the offspring's body weight and improves organogenesis. Therefore, leptin appears to play a major role in organogenesis, which may adversely affect the risk of developing a number of diseases in adulthood. Therefore, greater understanding of the role of leptin during development may assist in the prevention and treatment of a number of disease states that occur in adulthood.
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Affiliation(s)
- Jessica F Briffa
- Department of Physiology, University of Melbourne, Parkville, Australia
| | - Andrew J McAinch
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University, St. Albans, Australia; and
| | - Tania Romano
- Department of Human Biosciences, Latrobe University, Bundoora, Australia
| | - Mary E Wlodek
- Department of Physiology, University of Melbourne, Parkville, Australia
| | - Deanne H Hryciw
- Department of Physiology, University of Melbourne, Parkville, Australia;
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Tennekoon KH, Poopalapillai J, Karunanayake AG, Jayasinghe HD, Kumarasiri JM, De S Wijesundera AP, Karunanayake EH. Association of cord blood leptin, soluble leptin receptor, insulin-like growth factor-I and insulin-like growth factor-binding protein-1 on birth indices in healthy full-term newborns. Horm Res Paediatr 2015; 81:232-8. [PMID: 24557066 DOI: 10.1159/000356919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 10/14/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Leptin and insulin-like growth factor-I (IGF-I) promote fetal growth. Their availability is modulated by soluble leptin receptor (SLR) and insulin-like growth factor-binding proteins (IGFBP). Studies that accounted for SLR levels when investigating the association of leptin, IGF-I and IGFBPs on birth indices are scarce. METHODS Cord blood leptin, SLR, IGF-I, IGFBP-1 and their association with birth indices were studied in term newborns (n = 110; males = 60). Data were compared between males and females using the Mann-Whitney U test/unpaired Student's t test as appropriate. Univariate correlations and multiple regression analyses were performed to identify variables significantly influencing birth indices. RESULTS Birth indices were comparable between male and female newborns. Females had a significantly lower SLR (p = 0.0142), a higher leptin/Ponderal index (p = 0.033) and a higher free leptin index (leptin/SLR) (p = 0.0081). Leptin and male gender positively and IGFBP-1 negatively influenced birth weight (p = 0.0005, p = 0.02, and p = 0.005, respectively) and head circumference (p = 0.0052, p = 0.0098, and p = 0.0183, respectively) when accounted for other variables. When tested in a different multiple regression model, the free leptin index positively influenced crown-heel length (p = 0.0016) in addition to birth weight (p < 0.0001) and head circumference (p = 0.0016). CONCLUSIONS In healthy full-term pregnancies, cord blood leptin and IGFBP-1 exert independent and opposing effects on fetal growth.
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Affiliation(s)
- Kamani H Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka
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Ghantous CM, Azrak Z, Hanache S, Abou-Kheir W, Zeidan A. Differential Role of Leptin and Adiponectin in Cardiovascular System. Int J Endocrinol 2015; 2015:534320. [PMID: 26064110 PMCID: PMC4433709 DOI: 10.1155/2015/534320] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 04/23/2015] [Indexed: 02/07/2023] Open
Abstract
Leptin and adiponectin are differentially expressed adipokines in obesity and cardiovascular diseases. Leptin levels are directly associated with adipose tissue mass, while adiponectin levels are downregulated in obesity. Although significantly produced by adipocytes, leptin is also produced by vascular smooth muscle cells and cardiomyocytes. Plasma leptin concentrations are elevated in cases of cardiovascular diseases, such as hypertension, congestive heart failure, and myocardial infarction. As for the event of left ventricular hypertrophy, researchers have been stirring controversy about the role of leptin in this form of cardiac remodeling. In this review, we discuss how leptin has been shown to play an antihypertrophic role in the development of left ventricular hypertrophy through in vitro experiments, population-based cross-sectional studies, and longitudinal cohort studies. Conversely, we also examine how leptin may actually promote left ventricular hypertrophy using in vitro analysis and human-based univariate and multiple linear stepwise regression analysis. On the other hand, as opposed to leptin's generally detrimental effects on the cardiovascular system, adiponectin is a cardioprotective hormone that reduces left ventricular and vascular hypertrophy, oxidative stress, and inflammation. In this review, we also highlight adiponectin signaling and its protective actions on the cardiovascular system.
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Affiliation(s)
- C. M. Ghantous
- Department of Anatomy, Cell biology and Physiology, American University of Beirut, DTS-255, P.O. Box 11-0236, Beirut 1107-2020, Lebanon
| | - Z. Azrak
- Department of Pharmacology and Toxicology, American University of Beirut, DTS-255, P.O. Box 11-0236, Beirut 1107-2020, Lebanon
| | - S. Hanache
- Department of Anatomy, Cell biology and Physiology, American University of Beirut, DTS-255, P.O. Box 11-0236, Beirut 1107-2020, Lebanon
| | - W. Abou-Kheir
- Department of Anatomy, Cell biology and Physiology, American University of Beirut, DTS-255, P.O. Box 11-0236, Beirut 1107-2020, Lebanon
| | - A. Zeidan
- Department of Anatomy, Cell biology and Physiology, American University of Beirut, DTS-255, P.O. Box 11-0236, Beirut 1107-2020, Lebanon
- *A. Zeidan:
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Zemanová M, Staňková B, Ušiaková Z, Tvrzická E, Pazdro A, Petruželka L, Zeman M. Serum adiponectin relates to shortened overall survival in men with squamous cell esophageal cancer treated with preoperative concurrent chemoradiotherapy: a pilot study. Med Sci Monit 2014; 20:2351-7. [PMID: 25408239 PMCID: PMC4247235 DOI: 10.12659/msm.891088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 07/10/2014] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The convergence of nutritional, genetic, and inflammatory factors plays a significant role in the pathophysiology of squamous cell esophageal cancer (SCEC). The parameters of inflammation, indices of nutritional status, and adipocyte-derived hormones such as leptin, adiponectin, and resistin have been shown to be prognostic factors in some gastrointestinal and pancreatic cancers. MATERIAL/METHODS Forty-two patients with SCEC were subjected to a multimodal regimen of concurrent neoadjuvant chemoradiotherapy (CRT) followed by surgery. We retrospectively analyzed the impact of pretreatment values of serum leptin, adiponectin, resistin, soluble leptin receptor, C-reactive protein, TNF alpha, leukocytes, and indices of nutritional status (BMI, plasma total protein, albumin, cholesterol, and triacylglycerols) on overall survival (OS). RESULTS Univariate analysis revealed significant a negative correlation between OS and serum adiponectin (p=0.027), and a positive relationship was found between serum albumin (p=0.002), cholesterol (p=0.049) level, and OS. In multivariate analysis, only the trend (p=0.086) for negative serum adiponectin association with the OS was observed. CONCLUSIONS In men with SCEC treated by neoadjuvant concurrent CRT and esophagectomy, high pretreatment level of serum adiponectin was associated with shorter OS while the serum albumin and cholesterol were associated with longer OS.
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Affiliation(s)
- Milada Zemanová
- Clinic of Oncology, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
| | - Barbora Staňková
- 4 Department of Internal Medicine, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
| | - Zuzana Ušiaková
- Clinic of Oncology, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
| | - Eva Tvrzická
- 4 Department of Internal Medicine, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
| | - Alexandr Pazdro
- 3 Clinic of Surgery, 1 Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Luboš Petruželka
- Clinic of Oncology, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
| | - Miroslav Zeman
- 4 Department of Internal Medicine, 1 Faculty of Medicine of Charles University in Prague and General University Hospital, Prague, Czech Republic
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Peelman F, Zabeau L, Moharana K, Savvides SN, Tavernier J. 20 years of leptin: insights into signaling assemblies of the leptin receptor. J Endocrinol 2014; 223:T9-23. [PMID: 25063754 DOI: 10.1530/joe-14-0264] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Leptin plays a central role in the control of body weight and energy homeostasis, but is a pleiotropic cytokine with activities on many peripheral cell types. In this review, we discuss the interaction of leptin with its receptor, and focus on the structural and mechanistic aspects of the extracellular aspects of leptin receptor (LR) activation. We provide an extensive overview of all structural information that has been obtained for leptin and its receptor via X-ray crystallography, electron microscopy, small-angle X-ray scattering, homology modeling, and mutagenesis studies. The available knowledge is integrated into putative models toward a recapitulation of the LR activation mechanism.
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Affiliation(s)
- Frank Peelman
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Lennart Zabeau
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kedar Moharana
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Savvas N Savvides
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Jan Tavernier
- Department of Medical Protein ResearchFaculty of Medicine and Health Sciences, Flanders Institute for Biotechnology (VIB), Ghent University, A. Baertsoenkaai 3, 9000 Ghent, BelgiumUnit for Structural BiologyLaboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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Gong N, Björnsson BT. Leptin signaling in the rainbow trout central nervous system is modulated by a truncated leptin receptor isoform. Endocrinology 2014; 155:2445-55. [PMID: 24797628 DOI: 10.1210/en.2013-2131] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Central leptin (Lep) signaling is important in control of appetite and energy balance in mammals, but information on Lep signaling and physiological roles in early vertebrates is still lacking. To elucidate fish Lep signaling activation and modulation, a long-form Lep receptor (LepRL) and a truncated LepR (LepRT) are functionally characterized from rainbow trout. The receptors generated in alternatively splicing events have identical extracellular and transmembrane domains but differ in the intracellular sequence, both in length and identity. Gene transfection experiments show that LepRL is expressed as a 125-kDa protein in rainbow trout hepatoma cell line RTH-149, whereas LepRT is 100 kDa; both receptors specifically bind Lep. Homogenous Lep induces tyrosine phosphorylation of Janus kinase 2 and signal transducer and activation of transcription 3 in LepRL-expressing RTH-149 cells. This response is diminished in cells coexpressing LepRL and LepRT, suggesting that the LepRT which lacks these kinase-associated motifs competes with the LepRL for Lep availability, thus attenuating the Lep signal. Both receptor genes are highly expressed in the central nervous system. The mRNA levels of LepRT in hypothalamus, but not LepRL, change postprandially, with decreased transcription at 2 hours postfeeding and then elevated at 8 hours, concomitant with changes in proopiomelanocortin-A1 transcription. However, both receptors have no change in mRNA levels during 3 weeks of fasting. These data indicate that LepRT transcription is more likely a mechanism for modulating Lep effects on short-term feed intake than in regulating energy balance in the long term. In vitro and physiological characterization of LepR isoforms indicates divergent Lep signaling modulation patterns among vertebrates with different life histories and metabolic profiles.
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Affiliation(s)
- Ningping Gong
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, S-40590 Gothenburg, Sweden
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39
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Meharwade VV, Gayathri GV, Mehta DS. Effects of scaling and root planing with or without a local drug delivery system on the gingival crevicular fluid leptin level in chronic periodontitis patients: a clinico-biochemical study. J Periodontal Implant Sci 2014; 44:118-25. [PMID: 24921055 PMCID: PMC4050228 DOI: 10.5051/jpis.2014.44.3.118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 03/31/2014] [Indexed: 12/04/2022] Open
Affiliation(s)
| | | | - Dhoom Singh Mehta
- Department of Periodontics, Bapuji Dental College and Hospital, Davangere, India
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40
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McMurphy T, Xiao R, Magee D, Slater A, Zabeau L, Tavernier J, Cao L. The anti-tumor activity of a neutralizing nanobody targeting leptin receptor in a mouse model of melanoma. PLoS One 2014; 9:e89895. [PMID: 24587106 PMCID: PMC3938505 DOI: 10.1371/journal.pone.0089895] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 01/23/2014] [Indexed: 12/18/2022] Open
Abstract
Environmental and genetic activation of a brain-adipocyte axis inhibits cancer progression. Leptin is the primary peripheral mediator of this anticancer effect in a mouse model of melanoma. In this study we assessed the effect of a leptin receptor antagonist on melanoma progression. Local administration of a neutralizing nanobody targeting the leptin receptor at low dose adjacent to tumor decreased tumor mass with no effects on body weight or food intake. In contrast, systemic administration of the nanobody failed to suppress tumor growth. Daily intraperitoneal injection of high-dose nanobody led to weight gain, hyperphagia, increased adiposity, hyperleptinemia, and hyperinsulinemia, and central effects mimicking leptin deficiency. The blockade of central actions of leptin by systemic delivery of nanobody may compromise its anticancer effect, underscoring the need to develop peripherally acting leptin antagonists coupled with efficient cancer-targeting delivery.
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Affiliation(s)
- Travis McMurphy
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Run Xiao
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Daniel Magee
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Andrew Slater
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Lennart Zabeau
- Flanders Institute for Biotechnology, Department of Medical Protein Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Jan Tavernier
- Flanders Institute for Biotechnology, Department of Medical Protein Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Lei Cao
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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41
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Gill R, Cheung YH, Shen Y, Lanzano P, Mirza NM, Ten S, Maclaren NK, Motaghedi R, Han JC, Yanovski JA, Leibel RL, Chung WK. Whole-exome sequencing identifies novel LEPR mutations in individuals with severe early onset obesity. Obesity (Silver Spring) 2014; 22:576-84. [PMID: 23616257 PMCID: PMC3791145 DOI: 10.1002/oby.20492] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/02/2013] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Obesity is a major public health problem that increases the risk for a broad spectrum of co-morbid conditions. Despite evidence for a strong genetic contribution to susceptibility to obesity, previous efforts to discover the relevant genes using positional cloning have failed to account for most of the apparent genetic risk variance. DESIGN AND METHODS Deploying a strategy combining analysis of exome sequencing data in extremely obese members of four consanguineous families with segregation analysis, we screened for causal genetic variants. Filter-based analysis and homozygosity mapping were used to identify and prioritize putative functional variants. RESULTS Two novel frameshift mutations in the leptin receptor in two of the families were identified. CONCLUSIONS These results provide proof-of-principle that whole-exome sequencing of families segregating for extreme obesity can identify causal pathogenic mutations. The methods described here can be extended to additional families segregating for extreme obesity and should enable the identification of mutations in novel genes that predispose to obesity.
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Affiliation(s)
- Richard Gill
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
- Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY, USA
| | - Yee Him Cheung
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
| | - Yufeng Shen
- Department of Biomedical Informatics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
| | - Patricia Lanzano
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
| | - Nazrat M. Mirza
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD, USA
- Children’s National Medical Center, Washington, DC, USA
| | - Svetlana Ten
- Division of Pediatric Endocrinology at Maimonides Infants and Children’s Hospital of Brooklyn and SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Noel K. Maclaren
- Department of Pediatrics, Weill Medical College of Cornell University, New York, NY, USA
| | - Roja Motaghedi
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
| | - Joan C. Han
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD, USA
| | - Jack A. Yanovski
- Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD, USA
| | - Rudolph L. Leibel
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
| | - Wendy K. Chung
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, NY, USA
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42
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Golbidi S, Laher I. Exercise induced adipokine changes and the metabolic syndrome. J Diabetes Res 2014; 2014:726861. [PMID: 24563869 PMCID: PMC3915640 DOI: 10.1155/2014/726861] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 10/18/2013] [Indexed: 12/25/2022] Open
Abstract
The lack of adequate physical activity and obesity created a worldwide pandemic. Obesity is characterized by the deposition of adipose tissue in various parts of the body; it is now evident that adipose tissue also acts as an endocrine organ capable of secreting many cytokines that are though to be involved in the pathophysiology of obesity, insulin resistance, and metabolic syndrome. Adipokines, or adipose tissue-derived proteins, play a pivotal role in this scenario. Increased secretion of proinflammatory adipokines leads to a chronic inflammatory state that is accompanied by insulin resistance and glucose intolerance. Lifestyle change in terms of increased physical activity and exercise is the best nonpharmacological treatment for obesity since these can reduce insulin resistance, counteract the inflammatory state, and improve the lipid profile. There is growing evidence that exercise exerts its beneficial effects partly through alterations in the adipokine profile; that is, exercise increases secretion of anti-inflammatory adipokines and reduces proinflammatory cytokines. In this paper we briefly describe the pathophysiologic role of four important adipokines (adiponectin, leptin, TNF-α, and IL-6) in the metabolic syndrome and review some of the clinical trials that monitored these adipokines as a clinical outcome before and after exercise.
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Affiliation(s)
- Saeid Golbidi
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Ismail Laher
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
- *Ismail Laher:
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43
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Hsuchou H, Jayaram B, Kastin AJ, Wang Y, Ouyang S, Pan W. Endothelial cell leptin receptor mutant mice have hyperleptinemia and reduced tissue uptake. J Cell Physiol 2013; 228:1610-6. [PMID: 23359322 DOI: 10.1002/jcp.24325] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 01/14/2013] [Indexed: 11/10/2022]
Abstract
Hyperleptinemia is usually associated with obesity and leptin resistance. Endothelial cell leptin receptor knockout (ELKO) mice without a signaling membrane-bound leptin receptor in endothelia, however, have profound hyperleptinemia without signs of leptin resistance. Leptin mRNA in adipose tissue was unchanged. To test the hypothesis that the ELKO mutation results in delayed degradation and slowed excretion, we determined the kinetics of leptin transfer in groups of ELKO and wildtype mice after intravenous bolus injection of (125) I-leptin and the reference substance (131) I-albumin. The degradation pattern of (125) I-leptin in serum and brain homogenates at different time points between 10 and 60 min was measured by HPLC and acid precipitation. Although ELKO mice had reduced uptake of (125) I-leptin uptake by the brain and several peripheral organs, leptin was more stable in blood and tissue. There was no change in the rate of renal excretion. ELISA showed that serum soluble leptin receptor, known to antagonize leptin transport, had a 400-fold increase, probably contributing to the hyperleptinemia and reduced tissue uptake. Thus, the ELKO mutation unexpectedly increased the stability of leptin but suppressed its tissue uptake. These changes probably contribute to the known partial resistance of the ELKO mice to diet-induced obesity.
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Affiliation(s)
- Hung Hsuchou
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA
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44
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Karmazyn M, Gan XT, Rajapurohitam V. The potential contribution of circulating and locally produced leptin to cardiac hypertrophy and failure. Can J Physiol Pharmacol 2013; 91:883-8. [DOI: 10.1139/cjpp-2013-0057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Leptin is a 16 kDa peptide that was first identified in 1994 through positional cloning of the mouse obesity gene. Although the primary function of leptin is to act a satiety factor through its actions on the hypothalamus, it is now widely recognized that leptin can exert effects on many other organs through activation of its receptors, which are ubiquitously expressed. Leptin is secreted primarily by white adipocytes, but it is also produced by other tissues including the heart where it can exert effects in an autocrine or paracrine manner. One of these effects involves the induction of cardiomyocyte hypertrophy, which appears to occur via multiple cell signalling mechanisms. As adipocytes are the primary site of leptin production, plasma leptin concentrations are generally positively related with body mass index and the degree of adiposity. However, hyperleptinemia is also associated with cardiovascular disease, including heart failure, in the absence of obesity. Here we review the potential role of leptin in heart disease, particularly pertaining to its potential contribution to myocardial remodelling and heart failure, as well as the underlying mechanisms. We further discuss potential interactions between leptin and another adipokine, adiponectin, and the potential implications of this interaction in terms of fully understanding leptin’s effects.
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Affiliation(s)
- Morris Karmazyn
- Department of Physiology and Pharmacology, University of Western Ontario, Schulich School of Medicine and Dentistry, London, ON N6A 5C1, Canada
| | - Xiaohong Tracey Gan
- Department of Physiology and Pharmacology, University of Western Ontario, Schulich School of Medicine and Dentistry, London, ON N6A 5C1, Canada
| | - Venkatesh Rajapurohitam
- Department of Physiology and Pharmacology, University of Western Ontario, Schulich School of Medicine and Dentistry, London, ON N6A 5C1, Canada
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45
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Song M, Zhang X, Wu K, Ogino S, Fuchs CS, Giovannucci EL, Chan AT. Plasma adiponectin and soluble leptin receptor and risk of colorectal cancer: a prospective study. Cancer Prev Res (Phila) 2013; 6:875-85. [PMID: 23872505 DOI: 10.1158/1940-6207.capr-13-0169] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Adipokines are adipocyte-secreted hormones that may mediate the etiologic link between obesity and colorectal cancer; however, the evidence from large prospective studies is limited. We prospectively evaluated the association of plasma adiponectin and soluble leptin receptor (sOB-R) with colorectal cancer risk within the Nurses' Health Study (1990-2008) and the Health Professionals Follow-up Study (1994-2008) among 616 incident colorectal cancer cases and 1,205 controls selected using risk-set sampling and matched on age and date of blood draw. In unconditional logistic regression with adjustment for matching factors and multiple risk factors, plasma adiponectin was significantly associated with reduced risk of colorectal cancer among men, but not among women. Compared with men in the lowest quartile of adiponectin, men in the highest quartile had a relative risk (RR) for colorectal cancer of 0.55 [95% confidence interval (CI), 0.35-0.86; Ptrend = 0.02]. The corresponding RR in women was 0.96 (95% CI, 0.67-1.39; Ptrend = 0.74). Plasma sOB-R was not associated with overall colorectal cancer risk in either men or women. A significant heterogeneity was noted in the association between sOB-R and colorectal cancer by subsite in women (Pheterogeneity = 0.004); sOB-R was significantly associated with increased risk of rectal cancer but not colon cancer. These findings support a role for adiponectin in colorectal carcinogenesis in men. Further studies are warranted to confirm these associations and elucidate potential underlying mechanisms.
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Affiliation(s)
- Mingyang Song
- Division of Nutrition, Harvard Medical School, Boston, MA 02114, USA
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46
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Gong N, Einarsdottir IE, Johansson M, Björnsson BT. Alternative splice variants of the rainbow trout leptin receptor encode multiple circulating leptin-binding proteins. Endocrinology 2013; 154:2331-40. [PMID: 23645152 DOI: 10.1210/en.2012-2082] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In mammals, leptin (Lep) binding proteins (LepBPs) derived from Lep receptor (LepR) gene or protein bind most of the circulating Lep, but to date, information on LepBPs in nonmammalian vertebrate classes is lacking. This study details the characterization of multiple LepBPs in rainbow trout (Oncorhynchus mykiss), an early poikilothermic vertebrate, and presents the complete coding sequences for 3 of them. Size-exclusion chromatography and cross-linking assay identified plasma proteins bound to Lep ranging from 70 to 100 kDa. LepBPs were isolated from plasma by affinity chromatography, and their binding specificity was assessed by a competitive binding assay. A RIA for LepBPs indicates that plasma LepBP levels decline after fasting for 3 weeks. Immunoblotting of LepBPs using antibodies against different LepR epitopes shows that the LepBPs are indeed LepR isoforms. The alternatively spliced LepR transcripts (LepR(S1-3)) that include only the extracellular segment transcribe the 90-kDa LepBP1, the 80-kDa LepBP2, and the 70-kDa LepBP3, respectively. LepR(S1) generally has lower expression than the long-form LepR in most tissues. LepR(S2) is primarily expressed in adipose tissue, whereas LepR(S3) is expressed abundantly in brain and spleen, and moderately in liver and gills. The mRNA levels of hepatic LepR(S3) increase after 2 weeks of fasting. This study demonstrates a mechanism in fish for the generation of LepBPs that differs from that seen in mammals and indicates that the physiologic action of Lep in these poikilothermic vertebrates can be modulated, both centrally and peripherally, by the differentiated, tissue-specific expression of multiple LepBPs.
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Affiliation(s)
- Ningping Gong
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, S-40590 Gothenburg, Sweden.
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47
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Harris RBS. Direct and indirect effects of leptin on adipocyte metabolism. Biochim Biophys Acta Mol Basis Dis 2013; 1842:414-23. [PMID: 23685313 DOI: 10.1016/j.bbadis.2013.05.009] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 04/18/2013] [Accepted: 05/06/2013] [Indexed: 12/22/2022]
Abstract
Leptin is hypothesized to function as a negative feedback signal in the regulation of energy balance. It is produced primarily by adipose tissue and circulating concentrations correlate with the size of body fat stores. Administration of exogenous leptin to normal weight, leptin responsive animals inhibits food intake and reduces the size of body fat stores whereas mice that are deficient in either leptin or functional leptin receptors are hyperphagic and obese, consistent with a role for leptin in the control of body weight. This review discusses the effect of leptin on adipocyte metabolism. Because adipocytes express leptin receptors there is the potential for leptin to influence adipocyte metabolism directly. Adipocytes also are insulin responsive and receive sympathetic innervation, therefore leptin can also modify adipocyte metabolism indirectly. Studies published to date suggest that direct activation of adipocyte leptin receptors has little effect on cell metabolism in vivo, but that leptin modifies adipocyte sensitivity to insulin to inhibit lipid accumulation. In vivo administration of leptin leads to a suppression of lipogenesis, an increase in triglyceride hydrolysis and an increase in fatty acid and glucose oxidation. Activation of central leptin receptors also contributes to the development of a catabolic state in adipocytes, but this may vary between different fat depots. Leptin reduces the size of white fat depots by inhibiting cell proliferation both through induction of inhibitory circulating factors and by contributing to sympathetic tone which suppresses adipocyte proliferation. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Georgia Regents University, USA.
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48
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Golbidi S, Laher I. Potential mechanisms of exercise in gestational diabetes. J Nutr Metab 2013; 2013:285948. [PMID: 23691290 PMCID: PMC3649306 DOI: 10.1155/2013/285948] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/31/2013] [Accepted: 02/10/2013] [Indexed: 02/07/2023] Open
Abstract
Gestational diabetes mellitus (GDM) is defined as glucose intolerance first diagnosed during pregnancy. This condition shares same array of underlying abnormalities as occurs in diabetes outside of pregnancy, for example, genetic and environmental causes. However, the role of a sedentary lifestyle and/or excess energy intake is more prominent in GDM. Physically active women are less likely to develop GDM and other pregnancy-related diseases. Weight gain in pregnancy causes increased release of adipokines from adipose tissue; many adipokines increase oxidative stress and insulin resistance. Increased intramyocellular lipids also increase cellular oxidative stress with subsequent generation of reactive oxygen species. A well-planned program of exercise is an important component of a healthy lifestyle and, in spite of old myths, is also recommended during pregnancy. This paper briefly reviews the role of adipokines in gestational diabetes and attempts to shed some light on the mechanisms by which exercise can be beneficial as an adjuvant therapy in GDM. In this regard, we discuss the mechanisms by which exercise increases insulin sensitivity, changes adipokine profile levels, and boosts antioxidant mechanisms.
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Affiliation(s)
- Saeid Golbidi
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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49
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Shi X, Wang X, Li Q, Su M, Chew E, Wong ET, Lacza Z, Radda GK, Tergaonkar V, Han W. Nuclear factor κB (NF-κB) suppresses food intake and energy expenditure in mice by directly activating the Pomc promoter. Diabetologia 2013; 56:925-36. [PMID: 23370526 DOI: 10.1007/s00125-013-2831-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 12/28/2012] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS While chronic low-grade inflammation is associated with obesity, acute inflammation reduces food intake and leads to negative energy balance. Although both types of inflammation activate nuclear factor κB (NF-κB) signalling, it remains unclear how NF-κB activation results in opposite physiological responses in the two types of inflammation. The goal of this study was to address this question, and to understand the link between inflammation and leptin signalling. METHODS We studied the ability of NF-κB to modulate Pomc transcription, and how it impinges on signal transducer and activator of transcription 3 (STAT3)-mediated leptin signalling by using a combination of animal models, biochemical assays and molecular biology. RESULTS We report that suppression of food intake and physical movement with acute inflammation is not dependent on STAT3 activation in pro-opiomelanocortin (POMC) neurons. Under these conditions, activated NF-κB independently leads to increased Pomc transcription. Electrophoretic mobility shift assay and chromatin immunoprecipitation (ChIP) experiments reveal that NF-κB v-rel reticuloendotheliosis viral oncogene homologue A (avian) (RELA [also known as p65]) binds to the Pomc promoter region between -138 and -88 bp, which also harbours the trans-acting transcription factor 1 (SP1) binding site. We found significant changes in the methylation pattern at this region and reduced Pomc activation under chronic inflammation induced by a high-fat diet. Furthermore, RELA is unable to bind and activate transcription when the Pomc promoter is methylated. Finally, RELA binds to STAT3 and inhibits STAT3-mediated promoter activity, suggesting that RELA, possibly together with forkhead box-containing protein 1 (FOXO1), may prevent STAT3-mediated leptin activation of the Pomc promoter. CONCLUSIONS/INTERPRETATION Our study provides a mechanism for the involvement of RELA in the divergent regulation of energy homeostasis in acute and chronic inflammation.
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Affiliation(s)
- X Shi
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, #02-02 Helios, 11 Biopolis Way, Singapore 138667, Republic of Singapore
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Tessier D, Ferraro Z, Gruslin A. Role of leptin in pregnancy: Consequences of maternal obesity. Placenta 2013; 34:205-11. [DOI: 10.1016/j.placenta.2012.11.035] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 11/23/2012] [Accepted: 11/29/2012] [Indexed: 10/27/2022]
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