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Swan P, Johnson B, le Roux CW, Miras AD. Harnessing the Melanocortin System in the control of food intake and glucose homeostasis. Peptides 2024:171255. [PMID: 38834138 DOI: 10.1016/j.peptides.2024.171255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/06/2024]
Abstract
The central and peripheral melanocortin system, comprising of five receptors and their endogenous ligands, is responsible for a wide array of physiological functions such as skin pigmentation, sexual function and development, and inflammation. A growing body of both clinical and pre-clinical research is demonstrating the relevance of this system in metabolic health. Disruption of hypothalamic melanocortin signalling is the most common cause of monogenic obesity in humans. Setmelanotide, an FDA-approved analogue of alpha-melanocyte stimulating hormone (α-MSH) that functions by restoring central melanocortin signalling, has proven to be a potent pharmacological tool in the treatment of syndromic obesity. As the first effective therapy targeting the melanocortin system to treat metabolic disorders, its approval has sparked research to further harness the links between these melanocortin receptors and metabolic processes. Here, we outline the structure of the central and peripheral melanocortin system, discuss its critical role in the regulation of food intake, and review promising targets that may hold potential to treat metabolic disorders in humans.
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Affiliation(s)
- Patrick Swan
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland; Diabetes Complications Research Centre, Conway Institute, University College Dublin, Dublin, Ireland
| | - Brett Johnson
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, United Kingdom
| | - Carel W le Roux
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland; Diabetes Complications Research Centre, Conway Institute, University College Dublin, Dublin, Ireland
| | - Alexander D Miras
- Diabetes Research Centre, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland; Division of Diabetes, Endocrinology and Metabolism, Imperial College London, United Kingdom
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2
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Volyanskaya AR, Akberdin IR, Kulyashov MA, Yevshin IS, Romanov MN, Shagimardanova EI, Gusev OA, Kolpakov FA. A bird's-eye overview of molecular mechanisms regulating feed intake in chickens-with mammalian comparisons. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2024; 17:61-74. [PMID: 38737579 PMCID: PMC11087724 DOI: 10.1016/j.aninu.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/29/2023] [Accepted: 01/10/2024] [Indexed: 05/14/2024]
Abstract
In recent decades, a lot of research has been conducted to explore poultry feeding behavior. However, up to now, the processes behind poultry feeding behavior remain poorly understood. The review generalizes modern expertise about the hormonal regulation of feeding behavior in chickens, focusing on signaling pathways mediated by insulin, leptin, and ghrelin and regulatory pathways with a cross-reference to mammals. This overview also summarizes state-of-the-art research devoted to hypothalamic neuropeptides that control feed intake and are prime candidates for predictors of feeding efficiency. Comparative analysis of the signaling pathways that mediate the feed intake regulation allowed us to conclude that there are major differences in the processes by which hormones influence specific neuropeptides and their contrasting roles in feed intake control between two vertebrate clades.
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Affiliation(s)
- Anastasiia R. Volyanskaya
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russia
- Biosoft.Ru, Ltd., Novosibirsk, Russia
| | - Ilya R. Akberdin
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russia
- Biosoft.Ru, Ltd., Novosibirsk, Russia
- Sirius University of Science and Technology, Sirius, Russia
| | - Mikhail A. Kulyashov
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russia
- Biosoft.Ru, Ltd., Novosibirsk, Russia
- Sirius University of Science and Technology, Sirius, Russia
| | - Ivan S. Yevshin
- Biosoft.Ru, Ltd., Novosibirsk, Russia
- Sirius University of Science and Technology, Sirius, Russia
| | - Michael N. Romanov
- School of Biosciences, University of Kent, Canterbury, UK
- L.K. Ernst Federal Research Centre for Animal Husbandry, Dubrovitsy, Podolsk, Russia
| | - Elena I. Shagimardanova
- Regulatory Genomics Research Center, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Oleg A. Gusev
- Regulatory Genomics Research Center, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
- Life Improvement By Future Technologies (LIFT) Center, Moscow, Russia
- Intractable Disease Research Center, Juntendo University, Tokyo, Japan
| | - Fedor A. Kolpakov
- Biosoft.Ru, Ltd., Novosibirsk, Russia
- Sirius University of Science and Technology, Sirius, Russia
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3
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Guan D, Men Y, Bartlett A, Hernández MAS, Xu J, Yi X, Li HS, Kong D, Mazitschek R, Ozcan U. Central inhibition of HDAC6 re-sensitizes leptin signaling during obesity to induce profound weight loss. Cell Metab 2024; 36:857-876.e10. [PMID: 38569472 DOI: 10.1016/j.cmet.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/02/2023] [Accepted: 02/13/2024] [Indexed: 04/05/2024]
Abstract
Leptin resistance during excess weight gain significantly contributes to the recidivism of obesity to leptin-based pharmacological therapies. The mechanisms underlying the inhibition of leptin receptor (LepR) signaling during obesity are still elusive. Here, we report that histone deacetylase 6 (HDAC6) interacts with LepR, reducing the latter's activity, and that pharmacological inhibition of HDAC6 activity disrupts this interaction and augments leptin signaling. Treatment of diet-induced obese mice with blood-brain barrier (BBB)-permeable HDAC6 inhibitors profoundly reduces food intake and leads to potent weight loss without affecting the muscle mass. Genetic depletion of Hdac6 in Agouti-related protein (AgRP)-expressing neurons or administration with BBB-impermeable HDAC6 inhibitors results in a lack of such anti-obesity effect. Together, these findings represent the first report describing a mechanistically validated and pharmaceutically tractable therapeutic approach to directly increase LepR activity as well as identifying centrally but not peripherally acting HDAC6 inhibitors as potent leptin sensitizers and anti-obesity agents.
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Affiliation(s)
- Dongxian Guan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yuqin Men
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexander Bartlett
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Jie Xu
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Xinchi Yi
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hu-Song Li
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Dong Kong
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ralph Mazitschek
- Massachusetts General Hospital, Center for Systems Biology, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Umut Ozcan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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4
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Liu S, Song S, Wang S, Cai T, Qin L, Wang X, Zhu G, Wang H, Yang W, Fang C, Wei Y, Zhou F, Yu Y, Lin S, Peng S, Li L. Hypothalamic FTO promotes high-fat diet-induced leptin resistance in mice through increasing CX3CL1 expression. J Nutr Biochem 2024; 123:109512. [PMID: 37907171 DOI: 10.1016/j.jnutbio.2023.109512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/02/2023]
Abstract
Long-term consumption of a high-fat diet (HFD) disrupts energy homeostasis and leads to weight gain. The fat mass and obesity-associated (FTO) gene has been consistently identified to be associated with HFD-induced obesity. The hypothalamus is crucial for regulating energy balance, and HFD-induced hypothalamic leptin resistance contributes to obesity. FTO, an N6-methyladenosine (m6A) RNA methylation regulator, may be a key mediator of leptin resistance. However, the exact mechanisms remain unclear. Therefore, the present study aims to investigate the association between FTO and leptin resistance. After HFD or standard diet (SD) feeding in male mice for 22 weeks, m6A-sequencing and western blotting assays were used to identify target genes and assess protein level, and molecular interaction changes. CRISPR/Cas9 gene knockout system was employed to investigate the potential function of FTO in leptin resistance and obesity. Our data showed that chemokine (C-X3-C motif) ligand 1 (CX3CL1) was a direct downstream target of FTO-mediated m6A modification. Furthermore, upregulation of FTO/CX3CL1 and suppressor of cytokine signaling 3 (SOCS3) in the hypothalamus impaired leptin-signal transducer and activator of transcription 3 signaling, resulting in leptin resistance and obesity. Compared to wild-type (WT) mice, FTO deficiency in leptin receptor-expressing neurons of the hypothalamus significantly inhibited the upregulation of CX3CL1 and SOCS3, and partially ameliorating leptin resistance under HFD conditions. Our findings reveal that FTO involved in the hypothalamic leptin resistance and provides novel insight into the function of FTO in the contribution to hypothalamic leptin resistance and obesity.
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Affiliation(s)
- Shujing Liu
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Shiyu Song
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Shuan Wang
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Tonghui Cai
- The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, P.R. China
| | - Lian Qin
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Xinzhuang Wang
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Guangming Zhu
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Haibo Wang
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Wenqi Yang
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Chunlu Fang
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Yuan Wei
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Fu Zhou
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China
| | - Yang Yu
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China; School of Sport and Health Sciences, Guangzhou Sport University, Guangzhou 510500, China
| | - Shaozhang Lin
- The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, P.R. China.
| | - Shuang Peng
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China; School of Sport and Health Sciences, Guangzhou Sport University, Guangzhou 510500, China.
| | - Liangming Li
- Key Laboratory of Sports Technique, Tactics and Physical Function of General Administration of Sport of China, Scientific Research Center, Guangzhou Sport University, Guangzhou 510500, P.R. China; School of Sport and Health Sciences, Guangzhou Sport University, Guangzhou 510500, China.
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5
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Oliveira LDC, Morais GP, de Oliveira FP, Mata MM, Vera ASC, da Rocha AL, Elias LLK, Teixeira GR, de Moraes C, Cintra DE, Ropelle ER, de Moura LP, Pauli JR, de Freitas EC, Rorato R, da Silva ASR. Intermittent fasting combined with exercise training reduces body mass and alleviates hypothalamic disorders induced by high-fat diet intake. J Nutr Biochem 2023:109372. [PMID: 37169229 DOI: 10.1016/j.jnutbio.2023.109372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 04/20/2023] [Accepted: 05/06/2023] [Indexed: 05/13/2023]
Abstract
High-fat diet consumption causes hypothalamic inflammation, dysregulating the leptin pathway, which, in turn, compromises the modulation of hypothalamic neuronal activities and predisposes obesity development. Intermittent fasting (IF) and exercise training (ET) have been demonstrated as efficient interventions to modulate hypothalamic inflammation and neuronal activity. However, no studies have evaluated whether combining these interventions could induce better results in reestablishing hypothalamic homeostasis disrupted by high-fat diet intake. The 8-week-old male C57BL/6 mice were randomly assigned into two groups: sedentary mice fed a standard diet (CT), and sedentary mice fed a high-fat diet (HF). After 8 weeks of an HF diet, part of the HF group (now 16 weeks old) was randomly subjected to different interventions for 6 weeks: HF-IF = HF diet mice submitted to IF; HF-T = HF diet mice submitted to ET; HF-IFT = HF diet mice submitted to IF and ET. All interventions decreased the body weight gain induced by high-fat diet intake, associated with reduced calorie consumption in week 14. Only the HF-IFT group presented improved serum insulin, leptin, resistin, and Tnf-alpha levels concomitantly with decreased hypothalamic inflammation. The HF-IFT group also demonstrated increased Pomc mRNA expression associated with enhanced pSTAT3 expression in the hypothalamic arcuate and ventromedial hypothalamic nuclei. Our data indicate that the beneficial effects of the combination of IF and ET on energy homeostasis are associated with increased leptin sensitivity in the hypothalamic arcuate nucleus and ventromedial hypothalamic nucleus, which is likely due to an improvement in hypothalamic inflammatory pathways in these nuclei.
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Affiliation(s)
- Luciana da Costa Oliveira
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Gustavo Paroschi Morais
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Franciane Pereira de Oliveira
- Laboratory of Stress Neuroendocrinology, Department of Biophysics, Paulista Medical School, Federal University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Milene Montavoni Mata
- Departament of Physiology, Ribeirão Preto Medical School, University of São Paulo, Brazil
| | - Allice Santos Cruz Vera
- Multicenter Graduate Program in Physiological Sciences, São Paulo State University (UNESP), Presidente Prudente, SP, Brazil
| | - Alisson Luiz da Rocha
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | | | - Giovana Rampazzo Teixeira
- Multicenter Graduate Program in Physiological Sciences, São Paulo State University (UNESP), Presidente Prudente, SP, Brazil
| | - Camila de Moraes
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Dennys E Cintra
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Eduardo R Ropelle
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Leandro P de Moura
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - José R Pauli
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Ellen C de Freitas
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rodrigo Rorato
- Laboratory of Stress Neuroendocrinology, Department of Biophysics, Paulista Medical School, Federal University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Adelino Sanchez R da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.; Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil..
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6
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Roy PK, Islam J, Lalhlenmawia H. Prospects of potential adipokines as therapeutic agents in obesity-linked atherogenic dyslipidemia and insulin resistance. Egypt Heart J 2023; 75:24. [PMID: 37014444 PMCID: PMC10073393 DOI: 10.1186/s43044-023-00352-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 03/28/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND In normal circumstances, AT secretes anti-inflammatory adipokines (AAKs) which regulates lipid metabolism, insulin sensitivity, vascular hemostasis, and angiogenesis. However, during obesity AT dysfunction occurs and leads to microvascular imbalance and secretes several pro-inflammatory adipokines (PAKs), thereby favoring atherogenic dyslipidemia and insulin resistance. Literature suggests decreased levels of circulating AAKs and increased levels of PAKs in obesity-linked disorders. Importantly, AAKs have been reported to play a vital role in obesity-linked metabolic disorders mainly insulin resistance, type-2 diabetes mellitus and coronary heart diseases. Interestingly, AAKs counteract the microvascular imbalance in AT and exert cardioprotection via several signaling pathways such as PI3-AKT/PKB pathway. Although literature reviews have presented a number of investigations detailing specific pathways involved in obesity-linked disorders, literature concerning AT dysfunction and AAKs remains sketchy. In view of the above, in the present contribution an effort has been made to provide an insight on the AT dysfunction and role of AAKs in modulating the obesity and obesity-linked atherogenesis and insulin resistance. MAIN BODY "Obesity-linked insulin resistance", "obesity-linked cardiometabolic disease", "anti-inflammatory adipokines", "pro-inflammatory adipokines", "adipose tissue dysfunction" and "obesity-linked microvascular dysfunction" are the keywords used for searching article. Google scholar, Google, Pubmed and Scopus were used as search engines for the articles. CONCLUSIONS This review offers an overview on the pathophysiology of obesity, management of obesity-linked disorders, and areas in need of attention such as novel therapeutic adipokines and their possible future perspectives as therapeutic agents.
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Affiliation(s)
- Probin Kr Roy
- Department of Pharmacy, Regional Institute of Paramedical and Nursing Sciences (RIPANS), Aizawl, Mizoram, 796017, India.
| | - Johirul Islam
- Coromandel International Limited, Hyderabad, Telangana, 500101, India
| | - Hauzel Lalhlenmawia
- Department of Pharmacy, Regional Institute of Paramedical and Nursing Sciences (RIPANS), Aizawl, Mizoram, 796017, India
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7
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Saxton RA, Caveney NA, Moya-Garzon MD, Householder KD, Rodriguez GE, Burdsall KA, Long JZ, Garcia KC. Structural insights into the mechanism of leptin receptor activation. Nat Commun 2023; 14:1797. [PMID: 37002197 PMCID: PMC10066393 DOI: 10.1038/s41467-023-37169-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/04/2023] [Indexed: 04/03/2023] Open
Abstract
Leptin is an adipocyte-derived protein hormone that promotes satiety and energy homeostasis by activating the leptin receptor (LepR)-STAT3 signaling axis in a subset of hypothalamic neurons. Leptin signaling is dysregulated in obesity, however, where appetite remains elevated despite high levels of circulating leptin. To gain insight into the mechanism of leptin receptor activation, here we determine the structure of a stabilized leptin-bound LepR signaling complex using single particle cryo-EM. The structure reveals an asymmetric architecture in which a single leptin induces LepR dimerization via two distinct receptor-binding sites. Analysis of the leptin-LepR binding interfaces reveals the molecular basis for human obesity-associated mutations. Structure-based design of leptin variants that destabilize the asymmetric LepR dimer yield both partial and biased agonists that partially suppress STAT3 activation in the presence of wild-type leptin and decouple activation of STAT3 from LepR negative regulators. Together, these results reveal the structural basis for LepR activation and provide insights into the differential plasticity of signaling pathways downstream of LepR.
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Affiliation(s)
- Robert A Saxton
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, 94720, USA.
| | - Nathanael A Caveney
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Maria Dolores Moya-Garzon
- Department of Pathology, Stanford University School of Medicine, Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Karsten D Householder
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Grayson E Rodriguez
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Program in Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Kylie A Burdsall
- Cancer Biology Program, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Jonathan Z Long
- Department of Pathology, Stanford University School of Medicine, Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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8
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Smooth Muscle Cells from a Rat Model of Obesity and Hyperleptinemia Are Partially Resistant to Leptin-Induced Reactive Oxygen Species Generation. Antioxidants (Basel) 2023; 12:antiox12030728. [PMID: 36978976 PMCID: PMC10045401 DOI: 10.3390/antiox12030728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/05/2023] [Accepted: 03/11/2023] [Indexed: 03/18/2023] Open
Abstract
The aim of this study was to evaluate the effect of leptin on reactive oxygen species’ (ROS) generation of smooth muscle cells (SMCs) from a rat model of obesity and hyperleptinemia. Obesity and hyperleptinemia were induced in rats by a sucrose-based diet for 24 weeks. ROS generation was detected by using dichloro-dihydrofluorescein (DCF), a fluorescent ROS probe in primary SMCs culture. An increase in plasma leptin and oxidative stress markers was observed in sucrose-fed (SF) rats. At baseline SMCs from SF rats showed a more than twofold increase in fluorescence intensity (FI) compared to that obtained in control (C) cells. When the C cells were treated with 20 ng leptin, the FI increased by about 200%, whereas the leptin-induced FI in the SF cells increased only by 60%. In addition, sucrose feeding increased the levels of p22phox and gp91phox, subunits of Nox as an O2•− source in SMCs. Treatment of cells with leptin significantly increased p22phox and gp91phox levels in C cells and did not affect SF cells. Regarding STAT3 phosphorylation and the content of PTP1B and SOCS3 as protein markers of leptin resistance, they were found to be significantly increased in SF cells. These results suggest that SF aortic SMCs are partially resistant to leptin-induced ROS generation.
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9
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Sharma Y, Galvão AM. Maternal obesity and ovarian failure: is leptin the culprit? Anim Reprod 2023; 19:e20230007. [PMID: 36855701 PMCID: PMC9968511 DOI: 10.1590/1984-3143-ar2023-0007] [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: 01/10/2023] [Accepted: 01/24/2023] [Indexed: 02/22/2023] Open
Abstract
At the time of its discovery and characterization in 1994, leptin was mostly considered a metabolic hormone able to regulate body weight and energy homeostasis. However, in recent years, a great deal of literature has revealed leptin's pleiotropic nature, through its involvement in numerous physiological contexts including the regulation of the female reproductive tract and ovarian function. Obesity has been largely associated with infertility, and leptin signalling is known to be dysregulated in the ovaries of obese females. Hence, the disruption of ovarian leptin signalling was shown to contribute to the pathophysiology of ovarian failure in obese females, affecting transcriptional programmes in the gamete and somatic cells. This review attempts to uncover the underlying mechanisms contributing to female infertility associated with obesity, as well as to shed light on the role of leptin in the metabolic dysregulation within the follicle, the effects on the oocyte epigenome, and the potential long-term consequence to embryo programming.
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Affiliation(s)
- Yashaswi Sharma
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland
| | - António Miguel Galvão
- Institute of Animal Reproduction and Food Research of PAS, Department of Reproductive Immunology and Pathology, Olsztyn, Poland,Babraham Institute, Epigenetics Programme, Cambridge, United Kingdom UK,Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom UK,Corresponding author: ;
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10
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Kim MH, Li Y, Zheng Q, Jiang L, Myers MG, Wu WS, Rui L. LepRb+ cell-specific deletion of Slug mitigates obesity and nonalcoholic fatty liver disease in mice. J Clin Invest 2023; 133:156722. [PMID: 36512408 PMCID: PMC9927931 DOI: 10.1172/jci156722] [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: 11/15/2021] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Leptin exerts its biological actions by activating the long-form leptin receptor (LepRb). LepRb signaling impairment and leptin resistance are believed to cause obesity. The transcription factor Slug - also known as Snai2 - recruits epigenetic modifiers and regulates gene expression by an epigenetic mechanism; however, its epigenetic action has not been explored in leptin resistance. Here, we uncover a proobesity function of neuronal Slug. Hypothalamic Slug was upregulated in obese mice. LepRb+ cell-specific Slug-knockout (SlugΔLepRb) mice were resistant to diet-induced obesity, type 2 diabetes, and liver steatosis and experienced decreased food intake and increased fat thermogenesis. Leptin stimulated hypothalamic Stat3 phosphorylation and weight loss to a markedly higher level in SlugΔLepRb than in Slugfl/fl mice, even before their body weight divergence. Conversely, hypothalamic LepRb+ neuron-specific overexpression of Slug, mediated by AAV-hSyn-DIO-Slug transduction, induced leptin resistance, obesity, and metabolic disorders in mice on a chow diet. At the genomic level, Slug bound to and repressed the LepRb promoter, thereby inhibiting LepRb transcription. Consistently, Slug deficiency decreased methylation of LepRb promoter H3K27, a repressive epigenetic mark, and increased LepRb mRNA levels in the hypothalamus. Collectively, these results unravel what we believe to be a previously unrecognized hypothalamic neuronal Slug/epigenetic reprogramming/leptin resistance axis that promotes energy imbalance, obesity, and metabolic disease.
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Affiliation(s)
- Min-Hyun Kim
- Department of Molecular & Integrative Physiology
| | - Yuan Li
- Department of Molecular & Integrative Physiology
| | | | - Lin Jiang
- Department of Molecular & Integrative Physiology
| | - Martin G Myers
- Department of Molecular & Integrative Physiology.,Division of Metabolism and Endocrinology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Wen-Shu Wu
- Division of Hematology/Oncology, Department of Medicine, University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Liangyou Rui
- Department of Molecular & Integrative Physiology.,Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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11
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Recent Advances in the Knowledge of the Mechanisms of Leptin Physiology and Actions in Neurological and Metabolic Pathologies. Int J Mol Sci 2023; 24:ijms24021422. [PMID: 36674935 PMCID: PMC9860943 DOI: 10.3390/ijms24021422] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
Excess body weight is frequently associated with low-grade inflammation. Evidence indicates a relationship between obesity and cancer, as well as with other diseases, such as diabetes and non-alcoholic fatty liver disease, in which inflammation and the actions of various adipokines play a role in the pathological mechanisms involved in these disorders. Leptin is mainly produced by adipose tissue in proportion to fat stores, but it is also synthesized in other organs, where leptin receptors are expressed. This hormone performs numerous actions in the brain, mainly related to the control of energy homeostasis. It is also involved in neurogenesis and neuroprotection, and central leptin resistance is related to some neurological disorders, e.g., Parkinson's and Alzheimer's diseases. In peripheral tissues, leptin is implicated in the regulation of metabolism, as well as of bone density and muscle mass. All these actions can be affected by changes in leptin levels and the mechanisms associated with resistance to this hormone. This review will present recent advances in the molecular mechanisms of leptin action and their underlying roles in pathological situations, which may be of interest for revealing new approaches for the treatment of diseases where the actions of this adipokine might be compromised.
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12
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Suh SB, Lee N, Kim J, Kim S, Jang S, Park JK, Lee K, Choi SY, Kwon HJ, Lee CH. Metformin ameliorates olanzapine-induced obesity and glucose intolerance by regulating hypothalamic inflammation and microglial activation in female mice. Front Pharmacol 2022; 13:906717. [PMID: 36313357 PMCID: PMC9596779 DOI: 10.3389/fphar.2022.906717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
Olanzapine (OLZ), a widely used second-generation antipsychotic drug, is known to cause metabolic side effects, including diabetes and obesity. Interestingly, OLZ-induced metabolic side effects have been demonstrated to be more profound in females in human studies and animal models. Metformin (MET) is often used as a medication for the metabolic side effects of OLZ. However, the mechanisms underlying OLZ-induced metabolic disturbances and their treatment remain unclear. Recent evidence has suggested that hypothalamic inflammation is a key component of the pathophysiology of metabolic disorders. On this background, we conducted this study with the following three objectives: 1) to investigate whether OLZ can independently induce hypothalamic microgliosis; 2) to examine whether there are sex-dependent differences in OLZ-induced hypothalamic microgliosis; and 3) to examine whether MET affects hypothalamic microgliosis. We found that administration of OLZ for 5 days induced systemic glucose intolerance and hypothalamic microgliosis and inflammation. Of note, both hypothalamic microglial activation and systemic glucose intolerance were far more evident in female mice than in male mice. The administration of MET attenuated hypothalamic microglial activation and prevented OLZ-induced systemic glucose intolerance and hypothalamic leptin resistance. Minocycline, a tetracycline derivative that prevents microgliosis, showed similar results when centrally injected. Our findings reveal that OLZ induces metabolic disorders by causing hypothalamic inflammation and that this inflammation is alleviated by MET administration.
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Affiliation(s)
- Sang Bum Suh
- University of Ulsan College of Medicine, Seoul, South Korea
| | - Nayoung Lee
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Jaedeok Kim
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Saeha Kim
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Sooyeon Jang
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Jong Kook Park
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Keunwook Lee
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Soo Young Choi
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Chan Hee Lee
- Department of Biomedical Science, Hallym University, Chuncheon, South Korea
- Program of Material Science for Medicine and Pharmaceutics, Hallym University, Chuncheon, South Korea
- *Correspondence: Chan Hee Lee,
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13
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Wee NKY, de Lima TFC, McGregor NE, Walker EC, Poulton IJ, Blank M, Sims NA. Leptin receptor in osteocytes promotes cortical bone consolidation in female mice. J Endocrinol 2022; 255:25-37. [PMID: 35938692 DOI: 10.1530/joe-22-0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/01/2022] [Indexed: 11/08/2022]
Abstract
Bone strength is partially determined during cortical bone consolidation, a process comprising coalescence of peripheral trabecular bone and its progressive mineralisation. Mice with genetic deletion of suppressor of cytokine signalling 3 (Socs3), an inhibitor of STAT3 signalling, exhibit delayed cortical bone consolidation, indicated by high cortical porosity, low mineral content, and low bone strength. Since leptin receptor (LepR) is expressed in the osteoblast lineage and is suppressed by SOCS3, we evaluated whether LepR deletion in osteocytes would rectify the Dmp1cre.Socs3fl/fl bone defect. First, we tested LepR deletion in osteocytes by generating Dmp1cre.LepRfl/fl mice and detected no significant bone phenotype. We then generated Dmp1cre.Socs3fl/fl.LepRfl/fl mice and compared them to Dmp1cre.Socs3fl/fl controls. Between 6 and 12 weeks of age, both Dmp1cre.Socs3fl/fl.LepRfl/fl and control (Dmp1cre.Socs3fl/fl) mice showed an increasing proportion of more heavily mineralised bone, indicating some cortical consolidation with time. However, at 12 weeks of age, rather than resolving the phenotype, delayed consolidation was extended in female Dmp1cre.Socs3fl/fl.LepRfl/fl mice. This was indicated in both metaphysis and diaphysis by greater proportions of low-density bone, lower proportions of high-density bone, and greater cortical porosity than Dmp1cre.Socs3fl/fl controls. There was also no change in the proportion of osteocytes staining positive for phospho-STAT3, suggesting the effect of LepR deletion in Dmp1cre.Socs3fl/fl mice is STAT3-independent. This identifies a new role for leptin signalling in bone which opposes our original hypothesis. Although LepR in osteocytes has no irreplaceable physiological role in normal bone maturation, when STAT3 is hyperactive, LepR in Dmp1Cre-expressing cells supports cortical consolidation.
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Affiliation(s)
- Natalie K Y Wee
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Thaísa F C de Lima
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Genetics and Molecular Biology, University of Campinas, São Paulo, Brazil
| | - Narelle E McGregor
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Emma C Walker
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Ingrid J Poulton
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Martha Blank
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
| | - Natalie A Sims
- Bone Cell Biology and Disease Unit, St Vincent's Institute of Medical Research, Fitzroy, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Melbourne, Australia
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14
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Amorim MR, Aung O, Mokhlesi B, Polotsky VY. Leptin-mediated neural targets in obesity hypoventilation syndrome. Sleep 2022; 45:zsac153. [PMID: 35778900 PMCID: PMC9453616 DOI: 10.1093/sleep/zsac153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/20/2022] [Indexed: 07/30/2023] Open
Abstract
Obesity hypoventilation syndrome (OHS) is defined as daytime hypercapnia in obese individuals in the absence of other underlying causes. In the United States, OHS is present in 10%-20% of obese patients with obstructive sleep apnea and is linked to hypoventilation during sleep. OHS leads to high cardiorespiratory morbidity and mortality, and there is no effective pharmacotherapy. The depressed hypercapnic ventilatory response plays a key role in OHS. The pathogenesis of OHS has been linked to resistance to an adipocyte-produced hormone, leptin, a major regulator of metabolism and control of breathing. Mechanisms by which leptin modulates the control of breathing are potential targets for novel therapeutic strategies in OHS. Recent advances shed light on the molecular pathways related to the central chemoreceptor function in health and disease. Leptin signaling in the nucleus of the solitary tract, retrotrapezoid nucleus, hypoglossal nucleus, and dorsomedial hypothalamus, and anatomical projections from these nuclei to the respiratory control centers, may contribute to OHS. In this review, we describe current views on leptin-mediated mechanisms that regulate breathing and CO2 homeostasis with a focus on potential therapeutics for the treatment of OHS.
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Affiliation(s)
- Mateus R Amorim
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - O Aung
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Babak Mokhlesi
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Vsevolod Y Polotsky
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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15
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Adipose Tissue Dysfunction and Obesity-Related Male Hypogonadism. Int J Mol Sci 2022; 23:ijms23158194. [PMID: 35897769 PMCID: PMC9330735 DOI: 10.3390/ijms23158194] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 12/12/2022] Open
Abstract
Obesity is a chronic illness associated with several metabolic derangements and comorbidities (i.e., insulin resistance, leptin resistance, diabetes, etc.) and often leads to impaired testicular function and male subfertility. Several mechanisms may indeed negatively affect the hypothalamic–pituitary–gonadal health, such as higher testosterone conversion to estradiol by aromatase activity in the adipose tissue, increased ROS production, and the release of several endocrine molecules affecting the hypothalamus–pituitary–testis axis by both direct and indirect mechanisms. In addition, androgen deficiency could further accelerate adipose tissue expansion and therefore exacerbate obesity, which in turn enhances hypogonadism, thus inducing a vicious cycle. Based on these considerations, we propose an overview on the relationship of adipose tissue dysfunction and male hypogonadism, highlighting the main biological pathways involved and the current therapeutic options to counteract this condition.
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16
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Early and Strong Leptin Reduction Is Predictive for Long-Term Weight Loss during High-Protein, Low-Glycaemic Meal Replacement-A Subanalysis of the Randomised-Controlled ACOORH Trial. Nutrients 2022; 14:nu14122537. [PMID: 35745267 PMCID: PMC9229506 DOI: 10.3390/nu14122537] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 02/01/2023] Open
Abstract
Lifestyle interventions including meal replacement are suitable for prevention and treatment of obesity and type-2-diabetes. Since leptin is involved in weight regulation, we hypothesised that a meal replacement-based lifestyle intervention would reduce leptin levels more effectively than lifestyle intervention alone. In the international, multicentre, randomised-controlled ACOORH-trial (Almased-Concept-against-Overweight-and-Obesity-and-Related- Health-Risk), overweight or obese participants with metabolic syndrome criteria (n = 463) were randomised into two groups and received telemonitoring devices and nutritional advice. The intervention group additionally used a protein-rich, low-glycaemic meal replacement. Data were collected at baseline, after 1, 3, 6, and 12 months. All datasets providing leptin data (n = 427) were included in this predefined subanalysis. Serum leptin levels significantly correlated with sex, body mass index, weight, and fat mass at baseline (p < 0.0001). Stronger leptin reduction has been observed in the intervention compared to the control group with the lowest levels after 1 month of intervention (estimated treatment difference −3.4 µg/L [1.4; 5.4] for females; −2.2 µg/L [1.2; 3.3] for males; p < 0.001 each) and was predictive for stronger reduction of body weight and fat mass (p < 0.001 each) over 12 months. Strongest weight loss was observed after 6 months (−5.9 ± 5.1 kg in females of the intervention group vs. −2.9 ± 4.9 kg in the control group (p < 0.0001); −6.8 ± 5.3 kg vs. −4.1 ± 4.4 kg (p = 0.003) in males) and in those participants with combined leptin and insulin decrease. A meal replacement-based lifestyle intervention effectively reduces leptin which is predictive for long-term weight loss.
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17
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The central nervous system control of energy homeostasis: high fat diet induced hypothalamic microinflammation and obesity. Brain Res Bull 2022; 185:99-106. [PMID: 35525336 DOI: 10.1016/j.brainresbull.2022.04.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 11/22/2022]
Abstract
Obesity is believed to arise through the imbalance of energy homeostasis controlled by the central nervous system, where the hypothalamus plays the fundamental role in energy metabolism. In this review, we will provide an overview regarding the functions of POMC neurons and AgRP neurons in acute nucleus of the hypothalamus which mediated the energy metabolism, highlighting their interactions with peripheral organs derived hormones in control of energy homeostasis. Furthermore, the role of high fat diet induced hypothalamic microinflammation in the pathogenesis of obesity will be discussed. We hope this review could help researchers to understand the mechanism of hypothalamus in control of energy metabolism, and design related drugs to block the pathways involving in the impaired metabolism in obese patients.
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18
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Naser W, Maymand S, Rivera LR, Connor T, Liongue C, Smith CM, Aston-Mourney K, McCulloch DR, McGee SL, Ward AC. Cytokine-inducible SH2 domain containing protein contributes to regulation of adiposity, food intake, and glucose metabolism. FASEB J 2022; 36:e22320. [PMID: 35470501 DOI: 10.1096/fj.202101882r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/24/2022] [Accepted: 04/06/2022] [Indexed: 01/03/2023]
Abstract
The cytokine-inducible SH2 domain containing protein (CISH) is the founding member of the suppressor of cytokine signaling (SOCS) family of negative feedback regulators and has been shown to be a physiological regulator of signaling in immune cells. This study sought to investigate novel functions for CISH outside of the immune system. Mice deficient in CISH were generated and analyzed using a range of metabolic and other parameters, including in response to a high fat diet and leptin administration. CISH knockout mice possessed decreased body fat and showed resistance to diet-induced obesity. This was associated with reduced food intake, but unaltered energy expenditure and microbiota composition. CISH ablation resulted in reduced basal expression of the orexigenic Agrp gene in the arcuate nucleus (ARC) region of the brain. Cish was basally expressed in the ARC, with evidence of co-expression with the leptin receptor (Lepr) gene in Agrp-positive neurons. CISH-deficient mice also showed enhanced leptin responsiveness, although Cish expression was not itself modulated by leptin. CISH-deficient mice additionally exhibited improved insulin sensitivity on a high-fat diet, but not glucose tolerance despite reduced body weight. These data identify CISH as an important regulator of homeostasis through impacts on appetite control, mediated at least in part by negative regulation of the anorexigenic effects of leptin, and impacts on glucose metabolism.
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Affiliation(s)
- Wasan Naser
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,College of Science, University of Baghdad, Baghdad, Iraq
| | - Saeed Maymand
- School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Leni R Rivera
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Timothy Connor
- School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Clifford Liongue
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Craig M Smith
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Kathryn Aston-Mourney
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Daniel R McCulloch
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Sean L McGee
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
| | - Alister C Ward
- School of Medicine, Deakin University, Geelong, Victoria, Australia.,IMPACT, Deakin University, Geelong, Victoria, Australia
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19
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Inamori KI. Regulation of Leptin Receptor Signaling by Gangliosides. TRENDS GLYCOSCI GLYC 2022. [DOI: 10.4052/tigg.2106.1j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Kei-ichiro Inamori
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University
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20
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Inamori KI. Regulation of Leptin Receptor Signaling by Gangliosides. TRENDS GLYCOSCI GLYC 2022. [DOI: 10.4052/tigg.2106.1e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Kei-ichiro Inamori
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University
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21
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Zieba DA, Szczesna M, Kirsz K, Biernat W. Effects of Leptin, Growth Hormone and Photoperiod on Pituitary SOCS-3 Expression in Sheep. Animals (Basel) 2022; 12:ani12030403. [PMID: 35158726 PMCID: PMC8833742 DOI: 10.3390/ani12030403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/06/2022] [Accepted: 02/02/2022] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Maintaining energy homeostasis requires numerous processes and interactions between many systems. This study investigated the relationships between leptin, growth hormone (GH), and factors involved in cell signaling, such as suppressors of cytokine signaling-3 (SOCS-3). Exogenous or endogenous factors affecting these relationships may have different origins, and their interactions are determined in this study. The finding that the length of day significantly influenced the concentrations of growth hormone as well as pituitary leptin- and GH-dependent SOCS-3 expressions suggests that photoperiod plays an important role in regulating the physiological processes underlying adaptive phenomena in response to changing seasons in sheep, which facilitates energy homeostasis despite changing external and internal conditions. Abstract This study examined how leptin affects growth hormone (GH) release and investigated the effects of leptin, GH, and day length on the suppressor of cytokine signaling-3 (SOCS-3) mRNA levels in the adenohypophyses of sheep. The study consisted of two experiments. The first experiment was conducted during long (LD) and short (SD) days. Within-season and replicate sheep were centrally infused with Ringer-Locke buffer or leptin three times at 60-min intervals at the beginning of experiments. The second experiment involved adenohypophyses collected from sheep that were euthanized in May or November. Pituitary explants were treated with medium alone (Control) or medium with leptin or GH at different concentrations and incubated for various times. The results of the first experiment indicated GH concentrations were seasonally dependent and that leptin had no effect on GH secretion. The results of the second experiment indicated a stronger influence of leptin on the expression of SOCS-3 during the SD season than the LD season. During SDs, significant effects of both GH doses on SOCS-3 expression were observed. These results indicate a strong association between leptin, GH, and SOCS-3, which may explain the disruption of SOCS-3 leptin and GH signaling and the dominant effect of photoperiod on the above relationships.
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22
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Abstract
Leptin is a hormone primarily produced by the adipose tissue in proportion to the size of fat stores, with a primary function in the control of lipid reserves. Besides adipose tissue, leptin is also produced by other tissues, such as the stomach, placenta, and mammary gland. Altogether, leptin exerts a broad spectrum of short, medium, and long-term regulatory actions at the central and peripheral levels, including metabolic programming effects that condition the proper development and function of the adipose organ, which are relevant for its main role in energy homeostasis. Comprehending how leptin regulates adipose tissue may provide important clues to understand the pathophysiology of obesity and related diseases, such as type 2 diabetes, as well as its prevention and treatment. This review focuses on the physiological and long-lasting regulatory effects of leptin on adipose tissue, the mechanisms and pathways involved, its main outcomes on whole-body physiological homeostasis, and its consequences on chronic diseases.
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Affiliation(s)
- Catalina Picó
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands. CIBER de Fisiopatología de La Obesidad Y Nutrición (CIBEROBN). Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Mariona Palou
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands. CIBER de Fisiopatología de La Obesidad Y Nutrición (CIBEROBN). Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Catalina Amadora Pomar
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands. CIBER de Fisiopatología de La Obesidad Y Nutrición (CIBEROBN). Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Ana María Rodríguez
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands. CIBER de Fisiopatología de La Obesidad Y Nutrición (CIBEROBN). Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain.
| | - Andreu Palou
- Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics, Biomarkers and Risk Evaluation), University of the Balearic Islands. CIBER de Fisiopatología de La Obesidad Y Nutrición (CIBEROBN). Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
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23
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Ciriello J, Moreau JM, Caverson MM, Moranis R. Leptin: A Potential Link Between Obstructive Sleep Apnea and Obesity. Front Physiol 2022; 12:767318. [PMID: 35153807 PMCID: PMC8829507 DOI: 10.3389/fphys.2021.767318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/17/2021] [Indexed: 12/02/2022] Open
Abstract
Chronic intermittent hypoxia (CIH), a pathophysiological manifestation of obstructive sleep apnea (OSA), is strongly correlated with obesity, as patients with the disease experience weight gain while exhibiting elevated plasma levels of leptin. This study was done to determine whether a relationship may exist between CIH and obesity, and body energy balance and leptin signaling during CIH. Sprague-Dawley rats were exposed to 96 days of CIH or normoxic control conditions, and were assessed for measures of body weight, food and water intake, and food conversion efficiency. At the completion of the study leptin sensitivity, locomotor activity, fat pad mass and plasma leptin levels were determined within each group. Additionally, the hypothalamic arcuate nucleus (ARC) was isolated and assessed for changes in the expression of proteins associated with leptin receptor signaling. CIH animals were found to have reduced locomotor activity and food conversion efficiency. Additionally, the CIH group had increased food and water intake over the study period and had a higher body weight compared to normoxic controls at the end of the study. Basal plasma concentrations of leptin were significantly elevated in CIH exposed animals. To test whether a resistance to leptin may have occurred in the CIH animals due to the elevated plasma levels of leptin, an acute exogenous (ip) leptin (0.04 mg/kg carrier-free recombinant rat leptin) injection was administered to the normoxic and CIH exposed animals. Leptin injections into the normoxic controls reduced their food intake, whereas CIH animals did not alter their food intake compared to vehicle injected CIH animals. Within ARC, CIH animals had reduced protein expression of the short form of the obese (leptin) receptor (isoform OBR100) and showed a trend toward an elevated protein expression of the long form of obese (leptin) receptor (OBRb). In addition, pro-opiomelanocortin (POMC) protein expression was reduced, but increased expression of the phosphorylated extracellular-signal-regulated kinase 1/2 (pERK1/2) and of the suppressor of cytokine signaling 3 (SOCS3) proteins was observed in the CIH group, with little change in phosphorylated signal transducer and activator of transcription 3 (pSTAT3). Taken together, these data suggest that long-term exposure to CIH, as seen in obstructive sleep apnea, may contribute to a state of leptin resistance promoting an increase in body weight.
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24
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Suriagandhi V, Nachiappan V. Protective Effects of Melatonin against Obesity-Induced by Leptin Resistance. Behav Brain Res 2022; 417:113598. [PMID: 34563600 DOI: 10.1016/j.bbr.2021.113598] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/01/2021] [Accepted: 09/21/2021] [Indexed: 12/20/2022]
Abstract
Consumption of an exceedingly high-fat diet with irregular eating and sleeping habits is typical in the current sedentary lifestyle, leading to chronic diseases like obesity and diabetes mellitus. Leptin is a primary appetite-regulating hormone that binds to its receptors in the hypothalamic cell membrane and regulates downstream appetite-regulating neurons NPY/AgRp and POMC in the hypothalamus. Based on the fat content of the adipose tissue, leptin is secreted, and excess accumulation of fat in adipose tissue stimulates the abnormal secretion of leptin. The secreted leptin circulating in the bloodstream uses its transporters to cross the blood-brain barrier (BBB) and reach the CSF. There is a saturation limit for leptin bound to its transporters to cross the BBB, and increased leptin secretion in adipose tissue has a defect in its transport across the BBB. Leptin resistance is due to excess leptin, a saturation of its transporters, and deficiency in either the receptor level or signalling in the hypothalamus. Leptin resistance leads to obesity due to excess food intake and less energy expenditure. Normal leptin secretion follows a rhythm, and alteration in the lifestyle leads to hormonal imbalances and increases ROS generation leading to oxidative stress. The sleep disturbance causes obesity with increased lipid accumulation in adipose tissue. Melatonin is the master regulator of the sleep-wake cycle secreted by the pineal gland during the night. It is a potent antioxidant with anti-inflammatory properties. Melatonin is secreted in a pattern called the circadian rhythm in humans as well. Research indicates that melatonin plays a vital role in hormonal regulation and energy metabolism, including leptin signalling and secretion. Studying the role of melatonin in leptin regulation will help us combat the pathologies of obesity caused by leptin resistance.
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Affiliation(s)
- Vennila Suriagandhi
- Biomembrane Lab, Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamilnadu, India
| | - Vasanthi Nachiappan
- Biomembrane Lab, Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamilnadu, India.
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25
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Vohra MS, Benchoula K, Serpell CJ, Hwa WE. AgRP/NPY and POMC neurons in the arcuate nucleus and their potential role in treatment of obesity. Eur J Pharmacol 2022; 915:174611. [PMID: 34798121 DOI: 10.1016/j.ejphar.2021.174611] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 02/08/2023]
Abstract
Obesity is a major health crisis affecting over a third of the global population. This multifactorial disease is regulated via interoceptive neural circuits in the brain, whose alteration results in excessive body weight. Certain central neuronal populations in the brain are recognised as crucial nodes in energy homeostasis; in particular, the hypothalamic arcuate nucleus (ARC) region contains two peptide microcircuits that control energy balance with antagonistic functions: agouti-related peptide/neuropeptide-Y (AgRP/NPY) signals hunger and stimulates food intake; and pro-opiomelanocortin (POMC) signals satiety and reduces food intake. These neuronal peptides levels react to energy status and integrate signals from peripheral ghrelin, leptin, and insulin to regulate feeding and energy expenditure. To manage obesity comprehensively, it is crucial to understand cellular and molecular mechanisms of information processing in ARC neurons, since these regulate energy homeostasis. Importantly, a specific strategy focusing on ARC circuits needs to be devised to assist in treating obese patients and maintaining weight loss with minimal or no side effects. The aim of this review is to elucidate the recent developments in the study of AgRP-, NPY- and POMC-producing neurons, specific to their role in controlling metabolism. The impact of ghrelin, leptin, and insulin signalling via action of these neurons is also surveyed, since they also impact energy balance through this route. Lastly, we present key proteins, targeted genes, compounds, drugs, and therapies that actively work via these neurons and could potentially be used as therapeutic targets for treating obesity conditions.
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Affiliation(s)
- Muhammad Sufyan Vohra
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Khaled Benchoula
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Christopher J Serpell
- School of Physical Sciences, Ingram Building, University of Kent, Canterbury, Kent, CT2 7NH, United Kingdom
| | - Wong Eng Hwa
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia.
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26
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Bhusal A, Rahman MH, Suk K. Hypothalamic inflammation in metabolic disorders and aging. Cell Mol Life Sci 2021; 79:32. [PMID: 34910246 PMCID: PMC11071926 DOI: 10.1007/s00018-021-04019-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/01/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022]
Abstract
The hypothalamus is a critical brain region for the regulation of energy homeostasis. Over the years, studies on energy metabolism primarily focused on the neuronal component of the hypothalamus. Studies have recently uncovered the vital role of glial cells as an additional player in energy balance regulation. However, their inflammatory activation under metabolic stress condition contributes to various metabolic diseases. The recruitment of monocytes and macrophages in the hypothalamus helps sustain such inflammation and worsens the disease state. Neurons were found to actively participate in hypothalamic inflammatory response by transmitting signals to the surrounding non-neuronal cells. This activation of different cell types in the hypothalamus leads to chronic, low-grade inflammation, impairing energy balance and contributing to defective feeding habits, thermogenesis, and insulin and leptin signaling, eventually leading to metabolic disorders (i.e., diabetes, obesity, and hypertension). The hypothalamus is also responsible for the causation of systemic aging under metabolic stress. A better understanding of the multiple factors contributing to hypothalamic inflammation, the role of the different hypothalamic cells, and their crosstalks may help identify new therapeutic targets. In this review, we focus on the role of glial cells in establishing a cause-effect relationship between hypothalamic inflammation and the development of metabolic diseases. We also cover the role of other cell types and discuss the possibilities and challenges of targeting hypothalamic inflammation as a valid therapeutic approach.
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Affiliation(s)
- Anup Bhusal
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
| | - Md Habibur Rahman
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea
- Division of Endocrinology, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08901, USA
| | - Kyoungho Suk
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Daegu, 41944, Republic of Korea.
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41944, Republic of Korea.
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Adlanmerini M, Nguyen HC, Krusen BM, Teng CW, Geisler CE, Peed LC, Carpenter BJ, Hayes MR, Lazar MA. Hypothalamic REV-ERB nuclear receptors control diurnal food intake and leptin sensitivity in diet-induced obese mice. J Clin Invest 2021; 131:140424. [PMID: 33021965 DOI: 10.1172/jci140424] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/29/2020] [Indexed: 12/15/2022] Open
Abstract
Obesity occurs when energy expenditure is outweighed by energy intake. Tuberal hypothalamic nuclei, including the arcuate nucleus (ARC), ventromedial nucleus (VMH), and dorsomedial nucleus (DMH), control food intake and energy expenditure. Here we report that, in contrast with females, male mice lacking circadian nuclear receptors REV-ERBα and -β in the tuberal hypothalamus (HDKO mice) gained excessive weight on an obesogenic high-fat diet due to both decreased energy expenditure and increased food intake during the light phase. Moreover, rebound food intake after fasting was markedly increased in HDKO mice. Integrative transcriptomic and cistromic analyses revealed that such disruption in feeding behavior was due to perturbed REV-ERB-dependent leptin signaling in the ARC. Indeed, in vivo leptin sensitivity was impaired in HDKO mice on an obesogenic diet in a diurnal manner. Thus, REV-ERBs play a crucial role in hypothalamic control of food intake and diurnal leptin sensitivity in diet-induced obesity.
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Affiliation(s)
- Marine Adlanmerini
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Hoang Cb Nguyen
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Brianna M Krusen
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Clare W Teng
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Caroline E Geisler
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lindsey C Peed
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Bryce J Carpenter
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Matthew R Hayes
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine.,Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
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28
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Mohamed AA, Ahmed HH, ElSadek SM, Mohamed RS, El-Amir RY, Salah W, Sultan E, El-Hassib DMA, Fouad HM. A study of leptin and its gene 2548 G/A Rs7799039 single-nucleotide polymorphisms in Egyptian children: A single-center experience. Clin Res Hepatol Gastroenterol 2021; 45:101724. [PMID: 34089918 DOI: 10.1016/j.clinre.2021.101724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/18/2021] [Accepted: 05/11/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND/OBJECTIVES The pathophysiology of obesity is multifactorial, including genetic and environmental factors. Previous studies had highlighted the association of the leptin gene/receptor with obesity. We aimed to study the leptin gene rs7799039 single nucleotide polymorphism (SNP) in children, and its association with the children's characteristics. METHODS A cross-sectional analytic study that included 143 children with obesity (cases) and a comparable group of 86 lean children as controls. The anthropometric measures, blood pressure, and biochemical testing were done for all participants. The real-time polymerase chain reaction was used to detect rs7799039 SNP variant alleles and ELISA for leptin level assessment. RESULTS The distribution of rs7799039 SNPs genotypes GG/GA/AA was comparable between both groups. Testing children regardless of their body mass index showed that the abnormalities in blood pressure, lipids values, insulin resistance, and hepatic insulin sensitivity were significantly associated with increased leptin levels. Among cases, the abnormal metabolic status was associated with higher leptin levels. CONCLUSIONS The genotype' distribution of leptin gene rs7799039 SNP was similar in both children with obesity and those with normal-weight. The high blood pressure, abnormal lipid profile, and metabolic disturbances, were significantly associated with higher leptin levels and not with leptin gene rs7799039 SNP.
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Affiliation(s)
- Amal Ahmed Mohamed
- Department of Biochemistry, National Hepatology & Tropical Medicine Research Institute, Cairo, Egypt
| | - Hoda H Ahmed
- Department of Pediatrics, The National Research Centre, Egypt
| | - Sanaa M ElSadek
- Department of Pediatrics, Faculty of Medicine for Grils, Al-Azhar University, Egypt
| | - Rasha S Mohamed
- Department of Internal Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Reham Y El-Amir
- Department of Public Health, Faculty of Medicine, Cairo University, Egypt
| | - Wafaa Salah
- Department of Internal Medicine, The National Institute for Diabetes and Endocrinology, Egypt
| | - Eman Sultan
- Department of Endocrinology, The National Nutrition Institute, Egypt
| | - Dalia M Abd El-Hassib
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Benha University, Egypt
| | - Hanan M Fouad
- Department of Pediatrics, Faculty of Medicine, Helwan University, Cairo, Egypt.
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Multiple Leptin Signalling Pathways in the Control of Metabolism and Fertility: A Means to Different Ends? Int J Mol Sci 2021; 22:ijms22179210. [PMID: 34502119 PMCID: PMC8430761 DOI: 10.3390/ijms22179210] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/13/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023] Open
Abstract
The adipocyte-derived ‘satiety promoting’ hormone, leptin, has been identified as a key central regulator of body weight and fertility, such that its absence leads to obesity and infertility. Plasma leptin levels reflect body adiposity, and therefore act as an ‘adipostat’, whereby low leptin levels reflect a state of low body adiposity (under-nutrition/starvation) and elevated leptin levels reflect a state of high body adiposity (over-nutrition/obesity). While genetic leptin deficiency is rare, obesity-related leptin resistance is becoming increasingly common. In the absence of adequate leptin sensitivity, leptin is unable to exert its ‘anti-obesity’ effects, thereby exacerbating obesity. Furthermore, extreme leptin resistance and consequent low or absent leptin signalling resembles a state of starvation and can thus lead to infertility. However, leptin resistance occurs on a spectrum, and it is possible to be resistant to leptin’s metabolic effects while retaining leptin’s permissive effects on fertility. This may be because leptin exerts its modulatory effects on energy homeostasis and reproductive function through discrete intracellular signalling pathways, and these pathways are differentially affected by the molecules that promote leptin resistance. This review discusses the potential mechanisms that enable leptin to exert differential control over metabolic and reproductive function in the contexts of healthy leptin signalling and of diet-induced leptin resistance.
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30
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Leptin-Activity Modulators and Their Potential Pharmaceutical Applications. Biomolecules 2021; 11:biom11071045. [PMID: 34356668 PMCID: PMC8301849 DOI: 10.3390/biom11071045] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022] Open
Abstract
Leptin, a multifunctional hormone primarily, but not exclusively, secreted in adipose tissue, is implicated in a wide range of biological functions that control different processes, such as the regulation of body weight and energy expenditure, reproductive function, immune response, and bone metabolism. In addition, leptin can exert angiogenic and mitogenic actions in peripheral organs. Leptin biological activities are greatly related to its interaction with the leptin receptor. Both leptin excess and leptin deficiency, as well as leptin resistance, are correlated with different human pathologies, such as autoimmune diseases and cancers, making leptin and leptin receptor important drug targets. The development of leptin signaling modulators represents a promising strategy for the treatment of cancers and other leptin-related diseases. In the present manuscript, we provide an update review about leptin-activity modulators, comprising leptin mutants, peptide-based leptin modulators, as well as leptin and leptin receptor specific monoclonal antibodies and nanobodies.
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31
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Inokuchi JI, Kanoh H, Inamori KI, Nagafuku M, Nitta T, Fukase K. Homeostatic and pathogenic roles of the GM3 ganglioside. FEBS J 2021; 289:5152-5165. [PMID: 34125497 DOI: 10.1111/febs.16076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/10/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022]
Abstract
Two decades ago, we achieved molecular cloning of ganglioside GM3 synthase (GM3S; ST3GAL5), the enzyme responsible for initiating biosynthesis of complex gangliosides. The efforts of our research group since then have been focused on clarifying the physiological and pathological roles of gangliosides, particularly GM3. This review summarizes our long-term studies on the roles of GM3 in insulin resistance and adipogenesis in adipose tissues, cholesterol uptake in intestine, and leptin resistance in hypothalamus. We hypothesized that GM3 plays a role in innate immune function of macrophages and demonstrated that molecular species of GM3 with differing acyl-chain structures and modifications functioned as pro- and anti-inflammatory endogenous Toll-like receptor 4 (TLR4) modulators in macrophages. Very-long-chain and α-hydroxy GM3 species enhanced TLR4 activation, whereas long-chain and unsaturated GM3 species counteracted this effect. Lipidomic analyses of serum and adipose tissues revealed that imbalances between such pro- and anti-inflammatory GM3 species promoted progression of metabolic disorders. GM3 thus functions as a physiological regulatory factor controlling the balance between homeostatic and pathological states. Ongoing studies based on these findings will clarify the mechanisms underlying ganglioside-dependent control of energy homeostasis and innate immune responses.
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Affiliation(s)
- Jin-Ichi Inokuchi
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan.,Core for Medicine and Science Collaborative Research and Education (MS-CORE), Project Research Center for Fundamental Sciences, Osaka University, Japan
| | - Hirotaka Kanoh
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Kei-Ichiro Inamori
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Masakazu Nagafuku
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Takahiro Nitta
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Koichi Fukase
- Core for Medicine and Science Collaborative Research and Education (MS-CORE), Project Research Center for Fundamental Sciences, Osaka University, Japan.,Department of Chemistry, Graduate School of Science, Osaka University, Japan
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32
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Birlutiu V, Boicean LC. Serum leptin level as a diagnostic and prognostic marker in infectious diseases and sepsis: A comprehensive literature review. Medicine (Baltimore) 2021; 100:e25720. [PMID: 33907162 PMCID: PMC8084034 DOI: 10.1097/md.0000000000025720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 02/27/2021] [Accepted: 04/11/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Infections and sepsis are common causes of morbidity and mortality, with an increasing incidence worldwide. Leptin is involved in the inflammatory process and may modulate the cytokine production, immune cell proliferation and endothelial function. There are conflicting results regarding alterations of leptin levels in infectious diseases and the outcome from sepsis.The aim of the current article is to provide an overview of the medical literature on the correlations between variations of leptin levels and infectious diseases and sepsis. METHODS We performed an extensive literature search in PubMed and Google Scholar databases, using keywords to identify articles related to leptin in infectious diseases and sepsis. Searches were referenced using medical subject headings that included "leptin," "adipokines," "sepsis," "infectious diseases," "leptin deficiency," "leptin resistance" or "hyperleptinemia." The language of publication, journal, or country were not included as limitation criteria.Articles or abstracts containing adequate information, such as age, sex, anthropometric indices, clinical presentation, comorbidities, and management were included in the study, whereas articles with insufficient clinical and demographic data were excluded. We assessed the quality of the studies selected.The final review of all databases was conducted on June 18, 2020. RESULTS We find the results from the current review to be of great importance due to the possible therapeutic role of leptin analogs in states of leptin deficiency associated with infectious diseases or sepsis.In hyperleptinemia, a therapeutic plan for obtaining leptin neutralization also needs further investigations. This could lead to the reduction of proinflammatory responses.There is a need for further studies to demonstrate the specificity and sensitivity of leptin in the early diagnosis of sepsis and the need to measure serum leptin levels in routine evaluation of the critical patient. CONCLUSION The multiple effects of leptin are of growing interest, but further studies are needed to elucidate the role of leptin signalling in infectious diseases and sepsis. Because very few human studies are reported, we recommend the need for further research.Better understanding of the pathophysiology of sepsis and the implication of circulating total leptin in this process could help physicians in managing this life-threatening condition.
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Affiliation(s)
- Victoria Birlutiu
- “Lucian Blaga” University of Sibiu, Faculty of Medicine
- Academic Emergency Hospital Sibiu—Infectious Diseases Clinic, Sibiu, Romania
| | - Loredana Camelia Boicean
- “Lucian Blaga” University of Sibiu, Faculty of Medicine
- Academic Emergency Hospital Sibiu—Infectious Diseases Clinic, Sibiu, Romania
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33
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Sarma RR, Crossland MR, Eyck HJF, DeVore JL, Edwards RJ, Cocomazzo M, Zhou J, Brown GP, Shine R, Rollins LA. Intergenerational effects of manipulating DNA methylation in the early life of an iconic invader. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200125. [PMID: 33866803 DOI: 10.1098/rstb.2020.0125] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In response to novel environments, invasive populations often evolve rapidly. Standing genetic variation is an important predictor of evolutionary response but epigenetic variation may also play a role. Here, we use an iconic invader, the cane toad (Rhinella marina), to investigate how manipulating epigenetic status affects phenotypic traits. We collected wild toads from across Australia, bred them, and experimentally manipulated DNA methylation of the subsequent two generations (G1, G2) through exposure to the DNA methylation inhibitor zebularine and/or conspecific tadpole alarm cues. Direct exposure to alarm cues (an indicator of predation risk) increased the potency of G2 tadpole chemical cues, but this was accompanied by reductions in survival. Exposure to alarm cues during G1 also increased the potency of G2 tadpole cues, indicating intergenerational plasticity in this inducible defence. In addition, the negative effects of alarm cues on tadpole viability (i.e. the costs of producing the inducible defence) were minimized in the second generation. Exposure to zebularine during G1 induced similar intergenerational effects, suggesting a role for alteration in DNA methylation. Accordingly, we identified intergenerational shifts in DNA methylation at some loci in response to alarm cue exposure. Substantial demethylation occurred within the sodium channel epithelial 1 subunit gamma gene (SCNN1G) in alarm cue exposed individuals and their offspring. This gene is a key to the regulation of sodium in epithelial cells and may help to maintain the protective epidermal barrier. These data suggest that early life experiences of tadpoles induce intergenerational effects through epigenetic mechanisms, which enhance larval fitness. This article is part of the theme issue 'How does epigenetics influence the course of evolution?'
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Affiliation(s)
- Roshmi R Sarma
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia
| | - Michael R Crossland
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia
| | - Harrison J F Eyck
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia
| | - Jayna L DeVore
- School of Life and Environmental Sciences, The University of Sydney, Sydney 2006, Australia
| | - Richard J Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia
| | - Michael Cocomazzo
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong 3216, Australia
| | - Jia Zhou
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia.,School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB 1 Glen Osmond, 5064, Australia
| | - Gregory P Brown
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
| | - Richard Shine
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
| | - Lee A Rollins
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia.,Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong 3216, Australia
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34
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Liu H, Du T, Li C, Yang G. STAT3 phosphorylation in central leptin resistance. Nutr Metab (Lond) 2021; 18:39. [PMID: 33849593 PMCID: PMC8045279 DOI: 10.1186/s12986-021-00569-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/03/2021] [Indexed: 12/20/2022] Open
Abstract
Mechanism exploitation of energy homeostasis is urgently required because of the worldwide prevailing of obesity-related metabolic disorders in human being. Although it is well known that leptin plays a central role in regulating energy balance by suppressing food intake and promoting energy expenditure, the existence of leptin resistance in majority of obese individuals hampers the utilization of leptin therapy against these disorders. However, the mechanism of leptin resistance is largely unknown in spite of the globally enormous endeavors. Current theories to interpret leptin resistance include the impairment of leptin transport, attenuation of leptin signaling, chronic inflammation, ER tress, deficiency of autophagy, as well as leptin itself. Leptin-activated leptin receptor (LepRb) signals in hypothalamus via several pathways, in which JAK2-STAT3 pathway, the most extensively investigated one, is considered to mediate the major action of leptin in energy regulation. Upon leptin stimulation the phosphorylation of STAT3 is one of the key events in JAK2-STAT3 pathway, followed by the dimerization and nuclear translocation of this molecule. Phosphorylated STAT3 (p-STAT3), as a transcription factor, binds to and regulates its target gene such as POMC gene, playing the physiological function of leptin. Regarding POMC gene in hypothalamus however little is known about the detail of its interaction with STAT3. Moreover the status of p-STAT3 and its significance in hypothalamus of DIO mice needs to be well elucidated. This review comprehends literatures on leptin and leptin resistance and especially discusses what STAT3 phosphorylation would contribute to central leptin resistance.
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Affiliation(s)
- Huimin Liu
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Tianxin Du
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Chen Li
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China
| | - Guoqing Yang
- College of Life Science, Henan Agricultural University, 95 Wen Hua Road, Zhengzhou, 450002, China.
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35
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Beddows CA, Dodd GT. Insulin on the brain: The role of central insulin signalling in energy and glucose homeostasis. J Neuroendocrinol 2021; 33:e12947. [PMID: 33687120 DOI: 10.1111/jne.12947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/26/2022]
Abstract
Insulin signals to the brain where it coordinates multiple physiological processes underlying energy and glucose homeostasis. This review explores where and how insulin interacts within the brain parenchyma, how brain insulin signalling functions to coordinate energy and glucose homeostasis and how this contributes to the pathogenesis of metabolic disease.
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Affiliation(s)
- Cait A Beddows
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Garron T Dodd
- Department of Anatomy and Physiology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
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36
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Perakakis N, Farr OM, Mantzoros CS. Leptin in Leanness and Obesity: JACC State-of-the-Art Review. J Am Coll Cardiol 2021; 77:745-760. [PMID: 33573745 DOI: 10.1016/j.jacc.2020.11.069] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Leptin has emerged over the past 2 decades as a key hormone secreted by adipose tissue that conveys information on energy stores. Leptin is considered an important regulator of both neuroendocrine function and energy homeostasis. Numerous studies (mainly preclinical and much less in humans) have investigated the mechanisms of leptin's actions both in the healthy state as well as in a wide range of metabolic diseases. In this review, the authors present leptin physiology and review the main findings from animal studies, observational and interventional studies, and clinical trials in humans that have investigated the role of leptin in metabolism and cardiometabolic diseases (energy deficiency, obesity, diabetes, cardiovascular diseases, nonalcoholic fatty liver disease). The authors discuss the similarities and discrepancies between animal and human biology and present clinical applications of leptin, directions for future research, and current approaches for the development of the next-generation leptin analogs.
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Affiliation(s)
- Nikolaos Perakakis
- Department of Medicine, Boston VA Healthcare System, Boston, Massachusetts, USA; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Olivia M Farr
- Department of Medicine, Boston VA Healthcare System, Boston, Massachusetts, USA; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Christos S Mantzoros
- Department of Medicine, Boston VA Healthcare System, Boston, Massachusetts, USA; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
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37
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Chen X, Ren C, Teng Y, Shen Y, Wu M, Xiao H, Wang H. Effects of temperature on growth, development and the leptin signaling pathway of Bufo gargarizans. J Therm Biol 2020; 96:102822. [PMID: 33627262 DOI: 10.1016/j.jtherbio.2020.102822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 11/27/2022]
Abstract
Climate change is one of the most important causes of the decline in amphibians. Changes in temperature have an important effect on the growth and development and energy metabolism of amphibians. The aim of this study is to unravel the effects of temperature on the leptin signaling pathway of Bufo gargarizans and its molecular mechanisms. Our results showed that high temperature accelerated the development rate of tadpoles, but reduced body size and mass, while low temperature deferred the development of tadpoles, but increased size and mass. Both high temperature and low temperature exposure caused pathological damage of the liver in B. gargarizans. The results of RT-qPCR revealed that the high temperature treatment significantly upregulated the transcript levels of genes related to thyroid hormone (DIO2 (D2), Thyroid Hormone Receptor-α (TRα)) and the leptin signaling pathway (Leptin Receptor (LepR), Janus kinase 1 (JAK1), Janus kinase 2 (JAK2), Tyrosine kinase 2 (TYK2), Signal Transducer And Activator Of Transcription 3 (STAT3), Signal Transducer And Activator Of Transcription 3.1 (STAT3.1), and Signal Transducer And Activator Of Transcription 6 (STAT6)), while there was a decrease of mRNA expression of these genes (TRα, Thyroid Hormone Receptor-Beta (TRβ), LepR, JAK1, and TYK2) in the liver of tadpoles exposed to high temperature compared with the intermediate temperature treatment. Therefore, our results suggested that temperature extremes might interfere with the thyroid and leptin signaling pathways and affect the growth and development of B. gargarizans. Furthermore, tissue injury of the liver could occur due to exposure to temperature extremes. This work promotes public awareness of environmental protection and species conservation needs, also provides valuable experimental data and a theoretical basis for the protection of amphibians.
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Affiliation(s)
- Xiaoyan Chen
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Chaolu Ren
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Yiran Teng
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Yujia Shen
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Minyao Wu
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Hui Xiao
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China
| | - Hongyuan Wang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, China.
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Endurance Exercise Mitigates Immunometabolic Adipose Tissue Disturbances in Cancer and Obesity. Int J Mol Sci 2020; 21:ijms21249745. [PMID: 33371214 PMCID: PMC7767095 DOI: 10.3390/ijms21249745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Adipose tissue is considered an endocrine organ whose complex biology can be explained by the diversity of cell types that compose this tissue. The immune cells found in the stromal portion of adipose tissue play an important role on the modulation of inflammation by adipocytokines secretion. The interactions between metabolic active tissues and immune cells, called immunometabolism, is an important field for discovering new pathways and approaches to treat immunometabolic diseases, such as obesity and cancer. Moreover, physical exercise is widely known as a tool for prevention and adjuvant treatment on metabolic diseases. More specifically, aerobic exercise training is able to increase the energy expenditure, reduce the nutrition overload and modify the profile of adipocytokines and myokines with paracrine and endocrine effects. Therefore, our aim in this review was to cover the effects of aerobic exercise training on the immunometabolism of adipose tissue in obesity and cancer, focusing on the exercise-related modification on adipose tissue or immune cells isolated as well as their interaction.
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Zheng R, Liu R, Wu M, Wang H, Xie L. Effects of sodium perchlorate and exogenous L-thyroxine on growth, development and leptin signaling pathway of Bufo gargarizans tadpoles during metamorphosis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 206:111410. [PMID: 33007540 DOI: 10.1016/j.ecoenv.2020.111410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
Sodium perchlorate (NaClO4) and exogenous L-thyroxine (T4), two kinds of endocrine-disrupting chemicals (EDCs), mainly affect the circulating thyroid hormones, which regulate the initiation and rate of metamorphosis in amphibian. The aim of this study is to evaluate the potential role of EDCs in regulating the development of tadpoles and leptin signaling pathway of liver during the metamorphosis of Bufo gargarizans. There was completely opposite result of average development stage of tadpoles and morphological parameters between the NaClO4 and T4 exposure groups. Histological analysis revealed that NaClO4 and T4 exposure both caused liver injury, such as the decreased size of hepatocytes, atrophy of nucleus, increased melanomacrophage centres and disappearance of hepatocyte membranes. In addition, the results of RT-qPCR revealed that NaClO4 treatment significantly inhibited the transcript levels of genes related to thyroid hormone (D2, TRα and TRβ) and leptin signaling pathway (LepR, JAK1, JAK2, and TYK2), while there was an increase of mRNA expression of these genes in the liver of tadpoles administrated with T4 compared with control. This work lays an important foundation for assessing the risk of EDCs in relation to amphibian development during metamorphosis.
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Affiliation(s)
- Rui Zheng
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Rong Liu
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Minyao Wu
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Hongyuan Wang
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China.
| | - Lei Xie
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, 325035, Wenzhou, China; College of Life and Environmental Science, Wenzhou University, 325035, Wenzhou, China.
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Ferrer B, Prince LM, Tinkov AA, Santamaria A, Farina M, Rocha JB, Bowman AB, Aschner M. Chronic exposure to methylmercury enhances the anorexigenic effects of leptin in C57BL/6J male mice. Food Chem Toxicol 2020; 147:111924. [PMID: 33338554 DOI: 10.1016/j.fct.2020.111924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 02/06/2023]
Abstract
Several studies have demonstrated that heavy metals disrupt energy homeostasis. Leptin inhibits food intake and decreases body weight through activation of its receptor in the hypothalamus. The impact of heavy metals on leptin signaling in the hypothalamus is unclear. Here, we show that the environmental pollutant, methylmercury (MeHg), favors an anorexigenic profile in wild-type males. C57BL/6J mice were exposed to MeHg via drinking water (5 ppm) up to 30 days. Our data shows that MeHg exposure was associated with changes in leptin induced activation of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the hypothalamus. In males, the activation of JAK2/STAT3 signaling pathway was sustained by an increase in SOCS3 protein levels. In females, MeHg-activated STAT3 was inhibited by a concomitant increase in PTP1B. Taken together, our data suggest that MeHg enhanced leptin effects in males, favoring an anorexigenic profile in males, which notably, have been shown to be more sensitive to the neurological effects of this organometal than females. A better understanding of MeHg-induced molecular mechanism alterations in the hypothalamus advances the understanding of its neurotoxicity and provides molecular sites for novel therapies.
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Affiliation(s)
- Beatriz Ferrer
- Department of Molecular Pharmacology, Neuroscience, and Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, 10461, Bronx, NY, USA.
| | - Lisa M Prince
- School of Health Sciences, Purdue University, West Lafayette, IN, United States.
| | - Alexey A Tinkov
- Yaroslavl State University, Yaroslavl, Russia; IM Sechenov First Moscow State Medical University, Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, Orenburg, Russia; Federal Research Centre of Biological Systems and Agro-technologies of the Russian Academy of Sciences, Orenburg, Russia.
| | - Abel Santamaria
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, 14269, Mexico City, Mexico.
| | - Marcelo Farina
- Department of Biochemistry, Biological Sciences Center, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
| | - João Batista Rocha
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN, United States.
| | - Michael Aschner
- Department of Molecular Pharmacology, Neuroscience, and Pediatrics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, 10461, Bronx, NY, USA; IM Sechenov First Moscow State Medical University, Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, Orenburg, Russia.
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Hu JCE, Bojarski C, Branchi F, Fromm M, Krug SM. Leptin Downregulates Angulin-1 in Active Crohn's Disease via STAT3. Int J Mol Sci 2020; 21:ijms21217824. [PMID: 33105684 PMCID: PMC7672602 DOI: 10.3390/ijms21217824] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022] Open
Abstract
Crohn’s disease (CD) has an altered intestinal barrier function, yet the underlying mechanisms remain to be disclosed. The tricellular tight junction protein tricellulin is involved in the maintenance of the paracellular macromolecule barrier and features an unchanged expression level in CD but a shifted localization. As angulins are known to regulate the localization of tricellulin, we hypothesized the involvement of angulins in CD. Using human biopsies, we found angulin-1 was downregulated in active CD compared with both controls and CD in remission. In T84 and Caco-2 monolayers, leptin, a cytokine secreted by fat tissue and affected in CD, decreased angulin-1 expression. This effect was completely blocked by STAT3 inhibitors, Stattic and WP1066, but only partially by JAK2 inhibitor AG490. The effect of leptin was also seen at a functional level as we observed in Caco-2 cells an increased permeability for FITC-dextran 4 kDa indicating an impaired barrier against macromolecule uptake. In conclusion, we were able to show that in active CD angulin-1 expression is downregulated, which leads to increased macromolecule permeability and is inducible by leptin via STAT3. This suggests that angulin-1 and leptin secretion are potential targets for intervention in CD to restore the impaired intestinal barrier.
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Affiliation(s)
- Jia-Chen E. Hu
- Institute of Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Christian Bojarski
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Federica Branchi
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
| | - Susanne M. Krug
- Institute of Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany
- Correspondence:
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Zieba DA, Biernat W, Barć J. Roles of leptin and resistin in metabolism, reproduction, and leptin resistance. Domest Anim Endocrinol 2020; 73:106472. [PMID: 32265081 DOI: 10.1016/j.domaniend.2020.106472] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 12/20/2022]
Abstract
Increased adipose mass can cause insulin resistance and type 2 diabetes mellitus. This phenomenon is related to adipocyte-secreted signaling molecules that affect glucose balance, such as fatty acids, adiponectin, leptin, interleukin-6, tumor necrosis factor-α, and resistin. Among these hormones, leptin and resistin play important roles in regulating weight and glucose metabolism. Leptin and resistin work in both similar and opposite ways, and they interact with each other. Circulating concentrations of leptin and resistin are elevated in models of obesity and rodents fed a high-fat diet. In addition, leptin and resistin are similarly regulated by nutritional status: they are reduced by fasting and increased by feeding. This effect is mediated partially through insulin receptors and glucose transporters. Our latest data provided the first indication that in sheep, intravenous infusion of resistin increases the mean circulating concentrations of leptin and decreases luteinizing hormone in a dose-dependent manner during both the long-day (LD) and short-day seasons. Furthermore, exogenous resistin increased suppressor of cytokine signaling (SOCS)-3 mRNA expression only during the LD season, when the leptin resistance/insensitivity phenomenon was observed in the arcuate nucleus, preoptic area, and anterior pituitary. We concluded that one factor contributing to central leptin resistance is autosuppression, via which leptin and resistin stimulate the expression of SOCS-3, which inhibits leptin signaling. The increased expression of SOCS-3 in response to leptin and resistin may be a pivotal cause of leptin resistance/insensitivity, a pathological situation in obese individuals and a physiological occurrence in sheep during the LD season.
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Affiliation(s)
- D A Zieba
- Department of Animal Nutrition and Biotechnology, and Fisheries, Agricultural University of Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland.
| | - W Biernat
- Department of Animal Nutrition and Biotechnology, and Fisheries, Agricultural University of Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland
| | - J Barć
- Department of Animal Nutrition and Biotechnology, and Fisheries, Agricultural University of Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland
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Yang Y, Xu Y. The central melanocortin system and human obesity. J Mol Cell Biol 2020; 12:785-797. [PMID: 32976556 PMCID: PMC7816681 DOI: 10.1093/jmcb/mjaa048] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/04/2020] [Accepted: 08/14/2020] [Indexed: 12/13/2022] Open
Abstract
The prevalence of obesity and the associated comorbidities highlight the importance of understanding the regulation of energy homeostasis. The central melanocortin system plays a critical role in controlling body weight balance. Melanocortin neurons sense and integrate the neuronal and hormonal signals, and then send regulatory projections, releasing anorexigenic or orexigenic melanocortin neuropeptides, to downstream neurons to regulate the food intake and energy expenditure. This review summarizes the latest progress in our understanding of the role of the melanocortin pathway in energy homeostasis. We also review the advances in the identification of human genetic variants that cause obesity via mechanisms that affect the central melanocortin system, which have provided rational targets for treatment of genetically susceptible patients.
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Affiliation(s)
- Yongjie Yang
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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Jafarpour S, Khosravi S, Janghorbani M, Mansourian M, Karimi R, Ghiasi MR, Miraghajani M, Symonds ME, Farajzadeghan Z, Salehi R. Association of serum and follicular fluid leptin and in vitro Fertilization/ ICSI outcome: A systematic review and meta-analysis. J Gynecol Obstet Hum Reprod 2020; 50:101924. [PMID: 33007525 DOI: 10.1016/j.jogoh.2020.101924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/09/2020] [Accepted: 09/23/2020] [Indexed: 10/23/2022]
Abstract
There are conflicting reports regarding circulating leptin and its relationship between pregnancy outcomes in infertile women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). We performed a systematic review and meta-analysis to assess the association between serum or follicular fluid (FF) leptin concentrations reported for infertile women and their IVF outcome. A systematic search was undertaken in available databases (PubMed, Scopus, Web of Science, The Cochrane Library and Embase) to find studies published up to Aug 2020 and the standardized mean difference with 95 % confidence interval was taken from 14 eligible studies. Both graphical (funnel plots) and test methods (Egger's regression test and the Begg) assessed the presence of publication bias. Subgroup analysis was used to investigate the source of heterogeneity. Pooled effect sizes based on the eligible papers indicated that of there is no statistically significant correlation between leptin levels in follicular fluid and serum on the day of ovum pick-up (OPU) and day of HCG (human chorionic gonadotrophin) administration in pregnant and non-pregnant women who underwent IVF/ICSI cycles. However, combination of leptin in serum and/or FF with other parameters may be a useful marker to predict IVF outcome.
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Affiliation(s)
- Sima Jafarpour
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Diseases Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sharifeh Khosravi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Diseases Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohsen Janghorbani
- Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Marjan Mansourian
- Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Raheleh Karimi
- Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Moosa Rahimi Ghiasi
- Laboratory of Basic Sciences, Mohammad Rasul Allah Research Tower, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maryam Miraghajani
- Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; The Early Life Research Unit, Academic Division of Child Health, Obstetrics and Gynaecology, and Nottingham Digestive Disease Centre and Biomedical Research Centre, The School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Michael E Symonds
- The Early Life Research Unit, Academic Division of Child Health, Obstetrics and Gynaecology, and Nottingham Digestive Disease Centre and Biomedical Research Centre, The School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Ziba Farajzadeghan
- Department of Community Medicine, Faculty Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Rasoul Salehi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Diseases Isfahan University of Medical Sciences, Isfahan, Iran.
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Seiffert P, Bugge K, Nygaard M, Haxholm GW, Martinsen JH, Pedersen MN, Arleth L, Boomsma W, Kragelund BB. Orchestration of signaling by structural disorder in class 1 cytokine receptors. Cell Commun Signal 2020; 18:132. [PMID: 32831102 PMCID: PMC7444064 DOI: 10.1186/s12964-020-00626-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/08/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Class 1 cytokine receptors (C1CRs) are single-pass transmembrane proteins responsible for transmitting signals between the outside and the inside of cells. Remarkably, they orchestrate key biological processes such as proliferation, differentiation, immunity and growth through long disordered intracellular domains (ICDs), but without having intrinsic kinase activity. Despite these key roles, their characteristics remain rudimentarily understood. METHODS The current paper asks the question of why disorder has evolved to govern signaling of C1CRs by reviewing the literature in combination with new sequence and biophysical analyses of chain properties across the family. RESULTS We uncover that the C1CR-ICDs are fully disordered and brimming with SLiMs. Many of these short linear motifs (SLiMs) are overlapping, jointly signifying a complex regulation of interactions, including network rewiring by isoforms. The C1CR-ICDs have unique properties that distinguish them from most IDPs and we forward the perception that the C1CR-ICDs are far from simple strings with constitutively bound kinases. Rather, they carry both organizational and operational features left uncovered within their disorder, including mechanisms and complexities of regulatory functions. CONCLUSIONS Critically, the understanding of the fascinating ability of these long, completely disordered chains to orchestrate complex cellular signaling pathways is still in its infancy, and we urge a perceptional shift away from the current simplistic view towards uncovering their full functionalities and potential. Video abstract.
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Affiliation(s)
- Pernille Seiffert
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Katrine Bugge
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Mads Nygaard
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Gitte W. Haxholm
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Jacob H. Martinsen
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Martin N. Pedersen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen Ø, Denmark
| | - Lise Arleth
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen Ø, Denmark
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100 Copenhagen Ø, Denmark
| | - Birthe B. Kragelund
- REPIN, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
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Roles of Gangliosides in Hypothalamic Control of Energy Balance: New Insights. Int J Mol Sci 2020; 21:ijms21155349. [PMID: 32731387 PMCID: PMC7432706 DOI: 10.3390/ijms21155349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 12/19/2022] Open
Abstract
Gangliosides are essential components of cell membranes and are involved in a variety of physiological processes, including cell growth, differentiation, and receptor-mediated signal transduction. They regulate functions of proteins in membrane microdomains, notably receptor tyrosine kinases such as insulin receptor (InsR) and epidermal growth factor receptor (EGFR), through lateral association. Studies during the past two decades using knockout (KO) or pharmacologically inhibited cells, or KO mouse models for glucosylceramide synthase (GCS; Ugcg), GM3 synthase (GM3S; St3gal5), and GD3 synthase (GD3S; St8sia1) have revealed essential roles of gangliosides in hypothalamic control of energy balance. The a-series gangliosides GM1 and GD1a interact with leptin receptor (LepR) and promote LepR signaling through activation of the JAK2/STAT3 pathway. Studies of GM3S KO cells have shown that the extracellular signal-regulated kinase (ERK) pathway, downstream of the LepR signaling pathway, is also modulated by gangliosides. Recent studies have revealed crosstalk between the LepR signaling pathway and other receptor signaling pathways (e.g., InsR and EGFR pathways). Gangliosides thus have the ability to modulate the effects of leptin by regulating functions of such receptors, and by direct interaction with LepR to control signaling.
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Kim JS, Kirkland RA, Lee SH, Cawthon CR, Rzepka KW, Minaya DM, de Lartigue G, Czaja K, de La Serre CB. Gut microbiota composition modulates inflammation and structure of the vagal afferent pathway. Physiol Behav 2020; 225:113082. [PMID: 32682966 DOI: 10.1016/j.physbeh.2020.113082] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 12/17/2022]
Abstract
Vagal afferent neurons (VAN), located in the nodose ganglion (NG) innervate the gut and terminate in the nucleus of solitary tract (NTS) in the brainstem. They are the primary sensory neurons integrating gut-derived signals to regulate meal size. Chronic high-fat diet (HFD) consumption impairs vagally mediated satiety, resulting in overfeeding. There is evidence that HFD consumption leads to alterations in both vagal nerve function and structural integrity. HFD also leads to marked gut microbiota dysbiosis; in rodent models, dysbiosis is sufficient to induce weight gain. In this study, we investigated the effect of microbiota dysbiosis on gut-brain vagal innervation independently of diet. To do so, we recolonized microbiota-depleted rats with gastrointestinal (GI) contents isolated from donor animals fed either a HFD (45 or 60% fat) or a low fat diet (LFD, 13% fat). We used two different depletion models while maintaining the animals on LFD: 1) conventionally raised Fischer and Wistar rats that underwent a depletion paradigm using an antibiotic cocktail and 2) germ free (GF) raised Fischer rats. Following recolonization, receiver animals were designated as ConvLF and ConvHF. Fecal samples were collected throughout these studies and analyzed via 16S Illumina sequencing. In both models, bacteria that were identified as characteristic of HFD were successfully transferred to recipient animals. Three weeks post-colonization, ConvHF rats showed significant increases in ionized calcium-binding adapter molecule-1 (Iba1) positive immune cells in the NG compared to ConvLF animals. Additionally, using isolectin B4 (IB4) staining to identify c-fibers, we found that, compared to ConvLF animals, ConvHF rats displayed decreased innervation at the level of the medial NTS; c-fibers at this level are believed to be primarily of vagal origin. This alteration in vagal structure was associated with a loss in satiety induced by the gut peptide cholecystokinin (CCK). Increased presence of immunocompetent Iba1+ cells along the gut-brain axis and alterations in NTS innervation were still evident in ConvHF rats compared to ConvLF animals 12 weeks post-colonization and were associated with increases in food intake and body weight (BW). We conclude from these data that microbiota dysbiosis can alter gut-brain vagal innervation, potentially via recruitment and/or activation of immune cells.
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Affiliation(s)
- J S Kim
- Dept. of Foods and Nutrition, USA
| | | | - S H Lee
- Dept. of Foods and Nutrition, USA
| | | | - K W Rzepka
- Dept. of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, GA, USA
| | - D M Minaya
- Dept. of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, GA, USA
| | - G de Lartigue
- Dept. of Pharmacodynamics, University of Florida, Gainesville, FL, USA
| | - K Czaja
- Dept. of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, GA, USA
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Sarma RR, Edwards RJ, Crino OL, Eyck HJF, Waters PD, Crossland MR, Shine R, Rollins LA. Do Epigenetic Changes Drive Corticosterone Responses to Alarm Cues in Larvae of an Invasive Amphibian? Integr Comp Biol 2020; 60:1481-1494. [PMID: 32544233 DOI: 10.1093/icb/icaa082] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The developmental environment can exert powerful effects on animal phenotype. Recently, epigenetic modifications have emerged as one mechanism that can modulate developmentally plastic responses to environmental variability. For example, the DNA methylation profile at promoters of hormone receptor genes can affect their expression and patterns of hormone release. Across taxonomic groups, epigenetic alterations have been linked to changes in glucocorticoid (GC) physiology. GCs are metabolic hormones that influence growth, development, transitions between life-history stages, and thus fitness. To date, relatively few studies have examined epigenetic effects on phenotypic traits in wild animals, especially in amphibians. Here, we examined the effects of exposure to predation threat (alarm cues) and experimentally manipulated DNA methylation on corticosterone (CORT) levels in tadpoles and metamorphs of the invasive cane toad (Rhinella marina). We included offspring of toads sampled from populations across the species' Australian range. In these animals, exposure to chemical cues from injured conspecifics induces shifts in developmental trajectories, putatively as an adaptive response that lessens vulnerability to predation. We exposed tadpoles to these alarm cues, and measured changes in DNA methylation and CORT levels, both of which are mechanisms that have been implicated in the control of phenotypically plastic responses in tadpoles. To test the idea that DNA methylation drives shifts in GC physiology, we also experimentally manipulated methylation levels with the drug zebularine. We found differentially methylated regions (DMRs) between control tadpoles and their full-siblings exposed to alarm cues, zebularine, or both treatments. However, the effects of these manipulations on methylation patterns were weaker than clutch (e.g., genetic, maternal, etc.) effects. CORT levels were higher in larval cane toads exposed to alarm cues and zebularine. We found little evidence of changes in DNA methylation across the GC receptor gene (NR3C1) promoter region in response to alarm cue or zebularine exposure. In both alarm cue and zebularine-exposed individuals, we found differentially methylated DNA in the suppressor of cytokine signaling 3 gene (SOCS3), which may be involved in predator avoidance behavior. In total, our data reveal that alarm cues have significant impacts on tadpole physiology, but show only weak links between DNA methylation and CORT levels. We also identify genes containing DMRs in tadpoles exposed to alarm cues and zebularine, particularly in range-edge populations, that warrant further investigation.
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Affiliation(s)
- Roshmi R Sarma
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Richard J Edwards
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ondi L Crino
- Centre for Integrative Ecology, School of Life and Environmental Sciences (LES), Deakin University, Geelong, Victoria, Australia.,Department of Biological Sciences, Macquarie University, NSW 2052, Australia
| | - Harrison J F Eyck
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Paul D Waters
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Michael R Crossland
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Richard Shine
- Department of Biological Sciences, Macquarie University, NSW 2052, Australia
| | - Lee A Rollins
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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Interaction of glucose sensing and leptin action in the brain. Mol Metab 2020; 39:101011. [PMID: 32416314 PMCID: PMC7267726 DOI: 10.1016/j.molmet.2020.101011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/27/2020] [Accepted: 05/05/2020] [Indexed: 01/10/2023] Open
Abstract
Background In response to energy abundant or deprived conditions, nutrients and hormones activate hypothalamic pathways to maintain energy and glucose homeostasis. The underlying CNS mechanisms, however, remain elusive in rodents and humans. Scope of review Here, we first discuss brain glucose sensing mechanisms in the presence of a rise or fall of plasma glucose levels, and highlight defects in hypothalamic glucose sensing disrupt in vivo glucose homeostasis in high-fat fed, obese, and/or diabetic conditions. Second, we discuss brain leptin signalling pathways that impact glucose homeostasis in glucose-deprived and excessed conditions, and propose that leptin enhances hypothalamic glucose sensing and restores glucose homeostasis in short-term high-fat fed and/or uncontrolled diabetic conditions. Major conclusions In conclusion, we believe basic studies that investigate the interaction of glucose sensing and leptin action in the brain will address the translational impact of hypothalamic glucose sensing in diabetes and obesity.
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Leptin stimulates synaptogenesis in hippocampal neurons via KLF4 and SOCS3 inhibition of STAT3 signaling. Mol Cell Neurosci 2020; 106:103500. [PMID: 32438059 DOI: 10.1016/j.mcn.2020.103500] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 03/25/2020] [Accepted: 05/05/2020] [Indexed: 01/26/2023] Open
Abstract
Normal development of neuronal connections in the hippocampus requires neurotrophic signals, including the cytokine leptin. During neonatal development, leptin induces formation and maturation of dendritic spines, the main sites of glutamatergic synapses in the hippocampal neurons. However, the molecular mechanisms for leptin-induced synaptogenesis are not entirely understood. In this study, we reveal two novel targets of leptin in developing hippocampal neurons and address their role in synaptogenesis. First target is Kruppel-Like Factor 4 (KLF4), which we identified using a genome-wide target analysis strategy. We show that leptin upregulates KLF4 in hippocampal neurons and that leptin signaling is important for KLF4 expression in vivo. Furthermore, KLF4 is required for leptin-induced synaptogenesis, as shKLF4 blocks and upregulation of KLF4 phenocopies it. We go on to show that KLF4 requires its signal transducer and activator of transcription 3 (STAT3) binding site and thus potentially blocks STAT3 activity to induce synaptogenesis. Second, we show that leptin increases the expression of suppressor of cytokine signaling 3 (SOCS3), another well-known inhibitor of STAT3, in developing hippocampal neurons. SOCS3 is also required for leptin-induced synaptogenesis and sufficient to stimulate it alone. Finally, we show that constitutively active STAT3 blocks the effects of leptin on spine formation, while the targeted knockdown of STAT3 is sufficient to induce it. Overall, our data demonstrate that leptin increases the expression of both KLF4 and SOCS3, inhibiting the activity of STAT3 in the hippocampal neurons and resulting in the enhancement of glutamatergic synaptogenesis during neonatal development.
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