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Hristov M, Landzhov B, Yakimova K. Effect of leptin on nitrergic neurons in the lateral hypothalamic area and the supraoptic nucleus of rats. Biotech Histochem 2024; 99:125-133. [PMID: 38533595 DOI: 10.1080/10520295.2024.2335167] [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] [Indexed: 03/28/2024] Open
Abstract
The adipocyte-derived hormone, leptin, plays a key role in the maintenance of energy homeostasis. Leptin binds to the long form of its receptor, which is predominantly expressed in various hypothalamic regions, including the lateral hypothalamic area (LH) and supraoptic nucleus (SO). Several studies have suggested that leptin directly activates neuronal nitric oxide synthase, leading to increased nitric oxide production. We used histochemistry for nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) as a marker for nitric oxide synthase activity and assessed the effect of leptin on nitrergic neurons in the LH and SO of rats. We found that intraperitoneal administration of leptin led to a significant increase in the number of NADPH-d-positive neurons in the LH and SO. In addition, the intensity (optical density) of NADPH-d staining in LH and SO neurons was significantly elevated in rats that received leptin compared with saline-treated rats. These findings suggest that nitrergic neurons in the LH and SO may be implicated in mediating the central effects of leptin.
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Affiliation(s)
- Milen Hristov
- Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
| | - Boycho Landzhov
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
| | - Krassimira Yakimova
- Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
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2
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Kian N, Bagheri A, Salmanpour F, Soltani A, Mohajer Z, Samieefar N, Barekatain B, Kelishadi R. Breast feeding, obesity, and asthma association: clinical and molecular views. Clin Mol Allergy 2023; 21:8. [PMID: 37789370 PMCID: PMC10546753 DOI: 10.1186/s12948-023-00189-0] [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: 01/23/2023] [Accepted: 08/28/2023] [Indexed: 10/05/2023] Open
Abstract
Asthma is a chronic condition that affects children worldwide. Accumulating number of studies reported that the prevalence of pediatric obesity and asthma might be altered through breastfeeding. It has been proposed that Leptin, which exists in human milk, is oppositely associated with weight increase in newborns. It may also influence peripheral immune system by promoting TH1 responses and suppressing TH2 cytokines. Leptin influences body weight and immune responses through complex signaling pathways at molecular level. Although previous studies provide explanations for the protective role of breastfeeding against both obesity and asthma, other factors such as duration of breastfeeding, parental, and prenatal factors may confound this relationship which requires further research.
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Affiliation(s)
- Naghmeh Kian
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Alireza Bagheri
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
| | - Fardis Salmanpour
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
- Student Research Committee, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Afsaneh Soltani
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Zahra Mohajer
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Noosha Samieefar
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- USERN Office, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Behzad Barekatain
- Division of Neonatology, Department of Pediatrics, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roya Kelishadi
- Network of Interdisciplinarity in Neonates and Infants (NINI), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
- USERN Office, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
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3
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Liu J, Lai F, Hou Y, Zheng R. Leptin signaling and leptin resistance. MEDICAL REVIEW (BERLIN, GERMANY) 2022; 2:363-384. [PMID: 37724323 PMCID: PMC10388810 DOI: 10.1515/mr-2022-0017] [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: 06/06/2022] [Accepted: 07/12/2022] [Indexed: 09/20/2023]
Abstract
With the prevalence of obesity and associated comorbidities, studies aimed at revealing mechanisms that regulate energy homeostasis have gained increasing interest. In 1994, the cloning of leptin was a milestone in metabolic research. As an adipocytokine, leptin governs food intake and energy homeostasis through leptin receptors (LepR) in the brain. The failure of increased leptin levels to suppress feeding and elevate energy expenditure is referred to as leptin resistance, which encompasses complex pathophysiological processes. Within the brain, LepR-expressing neurons are distributed in hypothalamus and other brain areas, and each population of the LepR-expressing neurons may mediate particular aspects of leptin effects. In LepR-expressing neurons, the binding of leptin to LepR initiates multiple signaling cascades including janus kinase (JAK)-signal transducers and activators of transcription (STAT) phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), extracellular regulated protein kinase (ERK), and AMP-activated protein kinase (AMPK) signaling, etc., mediating leptin actions. These findings place leptin at the intersection of metabolic and neuroendocrine regulations, and render leptin a key target for treating obesity and associated comorbidities. This review highlights the main discoveries that shaped the field of leptin for better understanding of the mechanism governing metabolic homeostasis, and guides the development of safe and effective interventions to treat obesity and associated diseases.
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Affiliation(s)
- Jiarui Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Futing Lai
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Yujia Hou
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Ruimao Zheng
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
- Neuroscience Research Institute, Peking University, Beijing, China
- Key Laboratory for Neuroscience of Ministry of Education, Peking University, Beijing, China
- Key Laboratory for Neuroscience of National Health Commission, Peking University, Beijing 100191, China
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4
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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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5
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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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6
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Smiley KO, Dong L, Ramakrishnan S, Adkins-Regan E. Central prolactin receptor distribution and pSTAT5 activation patterns in breeding and non-breeding zebra finches (Taeniopygia guttata). Gen Comp Endocrinol 2021; 301:113657. [PMID: 33159912 DOI: 10.1016/j.ygcen.2020.113657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 10/23/2022]
Abstract
The hormone prolactin has many diverse functions across taxa such as osmoregulation, metabolism, and reproductive behavior. In ring doves, central prolactin action is important for parental care and feeding behavior. However, there is a considerable lack of information on the distribution of the prolactin receptor (PRLR) in the avian CNS to test the hypothesis that prolactin mediates these and other functions in other birds. In order to advance this research, we collected brains from breeding and non-breeding zebra finches to map the PRLR distribution using immunohistochemistry. We found PRLRs are distributed widely across the brain, both in hypothalamic sites known to regulate parental care and feeding, but also in many non-hypothalamic sites, including the tectofugal visual pathway, song system regions, reward associated areas, and pallium. This raises the possibility that prolactin has other functions throughout the brain that are not necessarily related to feeding or parental care. In addition, we also stained brains for pSTAT5, a transcription factor which is expressed when the PRLR is activated and is used as a marker for PRLR activity. We found several notable differences in pSTAT5 activity due to the breeding state of the animal, in both directions, further supporting the hypothesis that prolactin has many diverse functions in the brain both within and outside times of breeding. Together, this study represents the first essential step to inform the design of causative studies which manipulate PRLR-expressing cells to test their role in a wide variety of behaviors and other physiological functions.
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Affiliation(s)
- Kristina O Smiley
- Department of Psychology, Cornell University, Ithaca, NY 14853, USA.
| | - Longying Dong
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Selvakumar Ramakrishnan
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
| | - Elizabeth Adkins-Regan
- Department of Psychology, Cornell University, Ithaca, NY 14853, USA; Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
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7
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Olea-Flores M, Juárez-Cruz JC, Zuñiga-Eulogio MD, Acosta E, García-Rodríguez E, Zacapala-Gomez AE, Mendoza-Catalán MA, Ortiz-Ortiz J, Ortuño-Pineda C, Navarro-Tito N. New Actors Driving the Epithelial-Mesenchymal Transition in Cancer: The Role of Leptin. Biomolecules 2020; 10:E1676. [PMID: 33334030 PMCID: PMC7765557 DOI: 10.3390/biom10121676] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/12/2020] [Accepted: 12/13/2020] [Indexed: 12/24/2022] Open
Abstract
Leptin is a hormone secreted mainly by adipocytes; physiologically, it participates in the control of appetite and energy expenditure. However, it has also been linked to tumor progression in different epithelial cancers. In this review, we describe the effect of leptin on epithelial-mesenchymal transition (EMT) markers in different study models, including in vitro, in vivo, and patient studies and in various types of cancer, including breast, prostate, lung, and ovarian cancer. The different studies report that leptin promotes the expression of mesenchymal markers and a decrease in epithelial markers, in addition to promoting EMT-related processes such as cell migration and invasion and poor prognosis in patients with cancer. Finally, we report that leptin has the greatest biological relevance in EMT and tumor progression in breast, lung, prostate, esophageal, and ovarian cancer. This relationship could be due to the key role played by the enriched tumor microenvironment in adipose tissue. Together, these findings demonstrate that leptin is a key biomolecule that drives EMT and metastasis in cancer.
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Affiliation(s)
- Monserrat Olea-Flores
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
| | - Juan C. Juárez-Cruz
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
| | - Miriam D. Zuñiga-Eulogio
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
| | - Erika Acosta
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
| | - Eduardo García-Rodríguez
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
| | - Ana E. Zacapala-Gomez
- Laboratorio de Biomedicina Molecular, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (A.E.Z.-G.); (M.A.M.-C.); (J.O.-O.)
| | - Miguel A. Mendoza-Catalán
- Laboratorio de Biomedicina Molecular, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (A.E.Z.-G.); (M.A.M.-C.); (J.O.-O.)
| | - Julio Ortiz-Ortiz
- Laboratorio de Biomedicina Molecular, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (A.E.Z.-G.); (M.A.M.-C.); (J.O.-O.)
| | - Carlos Ortuño-Pineda
- Laboratorio de Ácidos Nucleicos y Proteinas, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico;
| | - Napoleón Navarro-Tito
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39090, Mexico; (M.O.-F.); (J.C.J.-C.); (M.D.Z.-E.); (E.A.); (E.G.-R.)
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8
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Glutamatergic Activation of Neuronostatin Neurons in the Periventricular Nucleus of the Hypothalamus. Brain Sci 2020; 10:brainsci10040217. [PMID: 32268550 PMCID: PMC7226416 DOI: 10.3390/brainsci10040217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 04/03/2020] [Indexed: 11/16/2022] Open
Abstract
Neuronostatin, a newly identified anorexigenic peptide, is present in the central nervous system. We tested the hypothesis that neuronostatin neurons are activated by feeding as a peripheral factor and that the glutamatergic system has regulatory influences on neuronostatin neurons. The first set of experiments analyzed the activation of neuronostatin neurons by refeeding as a physiological stimulus and the effectiveness of the glutamatergic system on this physiological stimulation. The subjects were randomly divided into three groups: the fasting group, refeeding group, and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)+refeeding group. We found that refeeding increased the phosphorylated signal transducers and transcription activator-5 (pSTAT5) expression in neuronostatin-positive neurons and that the CNQX injection significantly suppressed the number of pSTAT5-expressing neuronostatin neurons. The second set of experiments analyzed the activation pathways of neuronostatin neurons and the regulating effects of the glutamatergic system on neuronostatin neurons. The animals received intraperitoneal injections of glutamate receptor agonists (kainic acid, α-amino-3-hydroxy-5methyl-4-isoazepropionic acid (AMPA), and N-methyl-D-aspartate (NMDA)) or 0.9% NaCl. The number of c-Fos-expressing neuronostatin neurons significantly increased following the AMPA and NMDA injections. In conclusion, we found that the neuronostatin neurons were activated by peripheral or central signals, including food intake and/or glutamatergic innervation, and that the glutamate receptors played an important role in this activation.
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Abstract
Leptin is a hormone that plays a major role as mediator of long-term regulation of energy balance, suppressing food intake, and stimulating weight loss. More recently, important physiological roles other than controlling appetite and energy expenditure have been suggested for leptin, including neuroendocrine, reparative, reproductive, and immune functions. These emerging peripheral roles let hypothesize that leptin can modulate also cancer progression. Indeed, many studies have demonstrated that elevated chronic serum concentrations of leptin, frequently seen in obese subjects, represent a stimulatory signal for tumor growth. Current knowledge indicates that also different non-tumoral cells resident in tumor microenvironment may respond to leptin creating a favorable soil for cancer cells. In addition, leptin is produced also within the tumor microenvironment creating the possibility for paracrine and autocrine action. In this review, we describe the main mechanisms that regulate peripheral leptin availability and how leptin can shape tumor microenvironment.
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Polak KL, Chernosky NM, Smigiel JM, Tamagno I, Jackson MW. Balancing STAT Activity as a Therapeutic Strategy. Cancers (Basel) 2019; 11:cancers11111716. [PMID: 31684144 PMCID: PMC6895889 DOI: 10.3390/cancers11111716] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/23/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022] Open
Abstract
Driven by dysregulated IL-6 family member cytokine signaling in the tumor microenvironment (TME), aberrant signal transducer and activator of transcription (STAT3) and (STAT5) activation have been identified as key contributors to tumorigenesis. Following transformation, persistent STAT3 activation drives the emergence of mesenchymal/cancer-stem cell (CSC) properties, important determinants of metastatic potential and therapy failure. Moreover, STAT3 signaling within tumor-associated macrophages and neutrophils drives secretion of factors that facilitate metastasis and suppress immune cell function. Persistent STAT5 activation is responsible for cancer cell maintenance through suppression of apoptosis and tumor suppressor signaling. Furthermore, STAT5-mediated CD4+/CD25+ regulatory T cells (Tregs) have been implicated in suppression of immunosurveillance. We discuss these roles for STAT3 and STAT5, and weigh the attractiveness of different modes of targeting each cancer therapy. Moreover, we discuss how anti-tumorigenic STATs, including STAT1 and STAT2, may be leveraged to suppress the pro-tumorigenic functions of STAT3/STAT5 signaling.
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Affiliation(s)
- Kelsey L Polak
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Noah M Chernosky
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Jacob M Smigiel
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Ilaria Tamagno
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
| | - Mark W Jackson
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
- Case Comprehensive Cancer Center, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
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11
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Olea-Flores M, Juárez-Cruz JC, Mendoza-Catalán MA, Padilla-Benavides T, Navarro-Tito N. Signaling Pathways Induced by Leptin during Epithelial⁻Mesenchymal Transition in Breast Cancer. Int J Mol Sci 2018; 19:E3493. [PMID: 30404206 PMCID: PMC6275018 DOI: 10.3390/ijms19113493] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/27/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022] Open
Abstract
Leptin is an adipokine that is overexpressed in obese and overweight people. Interestingly, women with breast cancer present high levels of leptin and of its receptor ObR. Leptin plays an important role in breast cancer progression due to the biological processes it participates in, such as epithelial⁻mesenchymal transition (EMT). EMT consists of a series of orchestrated events in which cell⁻cell and cell⁻extracellular matrix interactions are altered and lead to the release of epithelial cells from the surrounding tissue. The cytoskeleton is also re-arranged, allowing the three-dimensional movement of epithelial cells into the extracellular matrix. This transition provides cells with the ability to migrate and invade adjacent or distal tissues, which is a classic feature of invasive or metastatic carcinoma cells. In recent years, the number of cases of breast cancer has increased, making this disease a public health problem worldwide and the leading cause of death due to cancer in women. In this review, we focus on recent advances that establish: (1) leptin as a risk factor for the development of breast cancer, and (2) leptin as an inducer of EMT, an event that promotes tumor progression.
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Affiliation(s)
- Monserrat Olea-Flores
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n, Chilpancingo, GRO 39090, México.
| | - Juan Carlos Juárez-Cruz
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n, Chilpancingo, GRO 39090, México.
| | - Miguel A Mendoza-Catalán
- Laboratorio de Biomedicina Molecular, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n, Chilpancingo, GRO 39090, México.
| | - Teresita Padilla-Benavides
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
| | - Napoleón Navarro-Tito
- Laboratorio de Biología Celular del Cáncer, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n, Chilpancingo, GRO 39090, México.
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12
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Leptin Signaling in the Control of Metabolism and Appetite: Lessons from Animal Models. J Mol Neurosci 2018; 66:390-402. [DOI: 10.1007/s12031-018-1185-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/24/2018] [Indexed: 12/15/2022]
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13
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Short-term fasting decreases excitatory synaptic inputs to ventromedial tuberoinfundibular dopaminergic neurons and attenuates their activity in male mice. Neurosci Lett 2018; 671:70-75. [DOI: 10.1016/j.neulet.2018.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/01/2018] [Accepted: 02/08/2018] [Indexed: 01/03/2023]
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14
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Brain STAT5 signaling modulates learning and memory formation. Brain Struct Funct 2018; 223:2229-2241. [PMID: 29460051 DOI: 10.1007/s00429-018-1627-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 02/12/2018] [Indexed: 01/02/2023]
Abstract
The signal transducer and activator of transcription 5 (STAT5) is a transcription factor recruited by numerous cytokines. STAT5 is important for several physiological functions, including body and tissue growth, mammary gland development, immune system and lipid metabolism. However, the role of STAT5 signaling for brain functions is still poorly investigated, especially regarding cognitive aspects. Therefore, the objective of the present study was to investigate whether brain STAT5 signaling modulates learning and memory formation. For this purpose, brain-specific STAT5 knockout (STAT5 KO) mice were studied in well-established memory tests. Initially, we confirmed a robust reduction in STAT5a and STAT5b mRNA levels in different brain structures of STAT5 KO mice. STAT5 KO mice showed no significant alterations in metabolism, growth, somatotropic axis and spontaneous locomotor activity. In contrast, brain-specific STAT5 ablation impaired learning and memory formation in the novel object recognition, Barnes maze and contextual fear conditioning tests. To unravel possible mechanisms that might underlie the memory deficits of STAT5 KO mice, we assessed neurogenesis in the hippocampus, but no significant differences were observed between groups. On the other hand, reduced insulin-like growth factor-1 (IGF-1) mRNA expression was found in the hippocampus and hypothalamus of STAT5 KO mice. These findings collectively indicate that brain STAT5 signaling is required to attain normal learning and memory. Therefore, STAT5 is an important downstream cellular mechanism shared by several cytokines to regulate cognitive functions.
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16
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Wauman J, Zabeau L, Tavernier J. The Leptin Receptor Complex: Heavier Than Expected? Front Endocrinol (Lausanne) 2017; 8:30. [PMID: 28270795 PMCID: PMC5318964 DOI: 10.3389/fendo.2017.00030] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/01/2017] [Indexed: 12/31/2022] Open
Abstract
Under normal physiological conditions, leptin and the leptin receptor (ObR) regulate the body weight by balancing food intake and energy expenditure. However, this adipocyte-derived hormone also directs peripheral processes, including immunity, reproduction, and bone metabolism. Leptin, therefore, can act as a metabolic switch connecting the body's nutritional status to high energy consuming processes. We provide an extensive overview of current structural insights on the leptin-ObR interface and ObR activation, coupling to signaling pathways and their negative regulation, and leptin functioning under normal and pathophysiological conditions (obesity, autoimmunity, cancer, … ). We also discuss possible cross-talk with other receptor systems on the receptor (extracellular) and signaling cascade (intracellular) levels.
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Affiliation(s)
- Joris Wauman
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Lennart Zabeau
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Jan Tavernier
- Cytokine Receptor Laboratory, Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
- VIB Medical Biotechnology Center, VIB, Ghent, Belgium
- *Correspondence: Jan Tavernier,
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Furigo IC, Ramos-Lobo AM, Frazão R, Donato J. Brain STAT5 signaling and behavioral control. Mol Cell Endocrinol 2016; 438:70-76. [PMID: 27118133 DOI: 10.1016/j.mce.2016.04.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/19/2016] [Accepted: 04/22/2016] [Indexed: 02/06/2023]
Abstract
Several growth factors and cytokines recruit the signal transducer and activator of transcription 5 (STAT5) signaling pathway to control cell proliferation, differentiation and apoptosis. Nonetheless, the importance of this transcription factor for brain functions is still poorly understood. Because some STAT5-inducing hormones, such as prolactin and leptin, act in the brain to regulate the expression of motivated behaviors, this signaling pathway is likely involved in behavioral modulation. Therefore, the objective of the present review was to summarize and discuss the available data regarding the possible role of central STAT5 signaling in the regulation of brain functions, especially on behavioral control. We discussed studies that investigated the importance of STAT5 signaling in the regulation of maternal and feeding behaviors. Additionally, we highlighted other behaviors that could be potentially affected by STAT5 signaling. This knowledge may help to understand how motivated behaviors are regulated at the cellular level.
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Affiliation(s)
- Isadora C Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Renata Frazão
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-900, Brazil
| | - J Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil.
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18
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Abstract
Leptin is a peptide hormone produced by adipose tissue and acts in brain centers to control critical physiological functions. Leptin receptors are especially abundant in the hypothalamus and trigger specific neuronal subpopulations, and activate several intracellular signaling events, including the JAK/STAT, MAPK, PI3K, and mTOR pathway. Although most studies focus on its role in energy intake and expenditure, leptin also plays a critical role in many central nervous system diseases.
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Hosoi T, Suyama Y, Kayano T, Ozawa K. Flurbiprofen Ameliorates Glucose Deprivation-Induced Leptin Resistance. Front Pharmacol 2016; 7:354. [PMID: 27746736 PMCID: PMC5042967 DOI: 10.3389/fphar.2016.00354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/16/2016] [Indexed: 12/17/2022] Open
Abstract
Leptin resistance is one of the mechanisms involved in the pathophysiology of obesity. The present study showed that glucose deprivation inhibited leptin-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3) and signal transducer and activator of transcription 5 (STAT5) in neuronal cells. Flurbiprofen reversed glucose deprivation-mediated attenuation of STAT3, but not STAT5 activation, in leptin-treated cells. Glucose deprivation increased C/EBP-homologous protein and glucose regulated protein 78 induction, indicating the activation of unfolded protein responses (UPR). Flurbiprofen did not affect the glucose deprivation-induced activation of UPR, but did attenuate the glucose deprivation-mediated induction of AMP-activated protein kinase phosphorylation. Flurbiprofen may ameliorate glucose deprivation-induced leptin resistance in neuronal cells.
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Affiliation(s)
- Toru Hosoi
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
| | - Yuka Suyama
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
| | - Takaaki Kayano
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
| | - Koichiro Ozawa
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
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20
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Shpakov AO. The brain leptin signaling system and its functional state in metabolic syndrome and type 2 diabetes mellitus. J EVOL BIOCHEM PHYS+ 2016. [DOI: 10.1134/s0022093016030017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Salais-López H, Lanuza E, Agustín-Pavón C, Martínez-García F. Tuning the brain for motherhood: prolactin-like central signalling in virgin, pregnant, and lactating female mice. Brain Struct Funct 2016; 222:895-921. [DOI: 10.1007/s00429-016-1254-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/16/2016] [Indexed: 10/21/2022]
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22
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Inflammatory transcription factors as activation markers and functional readouts in immune-to-brain communication. Brain Behav Immun 2016; 54:1-14. [PMID: 26348582 DOI: 10.1016/j.bbi.2015.09.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 08/31/2015] [Accepted: 09/04/2015] [Indexed: 02/06/2023] Open
Abstract
Immune-to-brain communication pathways involve humoral mediators, including cytokines, central modulation by neuronal afferents and immune cell trafficking to the brain. During systemic inflammation these pathways contribute to mediating brain-controlled sickness symptoms including fever. Experimentally, activation of these signaling pathways can be mimicked and studied when injecting animals with pathogen associated molecular patterns (PAMPS). One central component of the brain inflammatory response, which leads, for example, to fever induction, is transcriptional activation of brain cells via cytokines and PAMPS. We and others have studied the spatiotemporal activation and the physiological significance of transcription factors for the induction of inflammation within the brain and the manifestation of fever. Evidence has revealed a role of nuclear factor (NF)κB in the initiation, signal transducer and activator of transcription (STAT)3 in the maintenance and NF-interleukin (IL)6 in the maintenance or even termination of brain-inflammation and fever. Moreover, psychological stressors, such as exposure to a novel environment, leads to increased body core temperature and genomic NF-IL6-activation, suggesting a potential use of NF-IL6-immunohistochemistry as a multimodal brain cell activation marker and a role for NF-IL6 for differential brain activity. In addition, the nutritional status, as reflected by circulating levels of the cytokine-like hormone leptin, influence immune-to-brain communication and age-dependent changes in LPS-induced fever. Overall, transcription factors remain therapeutically important targets for the treatment of brain-inflammation and fever induction during infectious/non-infectious inflammatory and psychological stress. However, the exact physiological role and significance of these transcription factors requires to be further investigated.
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23
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Buonfiglio DC, Ramos-Lobo AM, Freitas VM, Zampieri TT, Nagaishi VS, Magalhães M, Cipolla-Neto J, Cella N, Donato J. Obesity impairs lactation performance in mice by inducing prolactin resistance. Sci Rep 2016; 6:22421. [PMID: 26926925 PMCID: PMC4772384 DOI: 10.1038/srep22421] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/15/2016] [Indexed: 12/30/2022] Open
Abstract
Obesity reduces breastfeeding success and lactation performance in women. However, the mechanisms involved are not entirely understood. In the present study, female C57BL/6 mice were chronically exposed to a high-fat diet to induce obesity and subsequently exhibited impaired offspring viability (only 15% survival rate), milk production (33% reduction), mammopoiesis (one-third of the glandular area compared to control animals) and postpartum maternal behaviors (higher latency to retrieving and grouping the pups). Reproductive experience attenuated these defects. Diet-induced obese mice exhibited high basal pSTAT5 levels in the mammary tissue and hypothalamus, and an acute prolactin stimulus was unable to further increase pSTAT5 levels above basal levels. In contrast, genetically obese leptin-deficient females showed normal prolactin responsiveness. Additionally, we identified the expression of leptin receptors specifically in basal/myoepithelial cells of the mouse mammary gland. Finally, high-fat diet females exhibited altered mRNA levels of ERBB4 and NRG1, suggesting that obesity may involve disturbances to mammary gland paracrine circuits that are critical in the control of luminal progenitor function and lactation. In summary, our findings indicate that high leptin levels are a possible cause of the peripheral and central prolactin resistance observed in obese mice which leads to impaired lactation performance.
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Affiliation(s)
- Daniella C Buonfiglio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Vanessa M Freitas
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Thais T Zampieri
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Vanessa S Nagaishi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Magna Magalhães
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Jose Cipolla-Neto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Nathalie Cella
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508-000, Brazil
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24
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Brain signaling systems in the Type 2 diabetes and metabolic syndrome: promising target to treat and prevent these diseases. Future Sci OA 2015; 1:FSO25. [PMID: 28031898 PMCID: PMC5137856 DOI: 10.4155/fso.15.23] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The changes in the brain signaling systems play an important role in etiology and pathogenesis of Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS), being a possible cause of these diseases. Therefore, their restoration at the early stages of T2DM and MS can be regarded as a promising way to treat and prevent these diseases and their complications. The data on the functional state of the brain signaling systems regulated by insulin, IGF-1, leptin, dopamine, serotonin, melanocortins and glucagon-like peptide-1, in T2DM and MS, are analyzed. The pharmacological approaches to restoration of these systems and improvement of insulin sensitivity, energy expenditure, lipid metabolism, and to prevent diabetic complications are discussed.
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25
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Severi I, Senzacqua M, Mondini E, Fazioli F, Cinti S, Giordano A. Activation of transcription factors STAT1 and STAT5 in the mouse median eminence after systemic ciliary neurotrophic factor administration. Brain Res 2015; 1622:217-29. [PMID: 26133794 DOI: 10.1016/j.brainres.2015.06.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/29/2015] [Accepted: 06/21/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Ilenia Severi
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Martina Senzacqua
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Eleonora Mondini
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
| | - Francesca Fazioli
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Saverio Cinti
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Center of Obesity, Università Politecnica delle Marche-United Hospitals, Ancona, Italy
| | - Antonio Giordano
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy.
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26
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Patil MJ, Henry MA, Akopian AN. Prolactin receptor in regulation of neuronal excitability and channels. Channels (Austin) 2015; 8:193-202. [PMID: 24758841 DOI: 10.4161/chan.28946] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Prolactin (PRL) activates PRL receptor isoforms to exert regulation of specific neuronal circuitries, and to control numerous physiological and clinically-relevant functions including; maternal behavior, energy balance and food intake, stress and trauma responses, anxiety, neurogenesis, migraine and pain. PRL controls these critical functions by regulating receptor potential thresholds, neuronal excitability and/or neurotransmission efficiency. PRL also influences neuronal functions via activation of certain neurons, resulting in Ca(2+) influx and/or electrical firing with subsequent release of neurotransmitters. Although PRL was identified almost a century ago, very little specific information is known about how PRL regulates neuronal functions. Nevertheless, important initial steps have recently been made including the identification of PRL-induced transient signaling pathways in neurons and the modulation of neuronal transient receptor potential (TRP) and Ca(2+) -dependent K(+) channels by PRL. In this review, we summarize current knowledge and recent progress in understanding the regulation of neuronal excitability and channels by PRL.
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27
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Farr OM, Tsoukas MA, Mantzoros CS. Leptin and the brain: influences on brain development, cognitive functioning and psychiatric disorders. Metabolism 2015; 64:114-30. [PMID: 25092133 DOI: 10.1016/j.metabol.2014.07.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/16/2014] [Accepted: 07/05/2014] [Indexed: 12/20/2022]
Abstract
Receptors of leptin, the prototypical adipokine, are expressed throughout the cortex and several other areas of the brain. Although typically studied for its role in energy intake and expenditure, leptin plays a critical role in many other neurocognitive processes and interacts with various other hormones and neurotransmitters to perform these functions. Here, we review the literature on how leptin influences brain development, neural degradation, Alzheimer's disease, psychiatric disorders, and more complicated cognitive functioning and feeding behaviors. We also discuss modulators of leptin and the leptin receptor as they relate to normal cognitive functioning and may mediate some of the actions of leptin in the brain. Although we are beginning to better understand the critical role leptin plays in normal cognitive functioning, there is much to be discovered.
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Affiliation(s)
- Olivia M Farr
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215.
| | - Michael A Tsoukas
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
| | - Christos S Mantzoros
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
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28
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Tian G, Liang JN, Wang ZY, Zhou D. Emerging role of leptin in rheumatoid arthritis. Clin Exp Immunol 2014; 177:557-70. [PMID: 24802245 DOI: 10.1111/cei.12372] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2014] [Indexed: 12/31/2022] Open
Abstract
Numerous studies have suggested the importance of leptin against autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS) and psoriasis. To summarize our current understanding of the role of leptin in inflammatory responses and rheumatoid arthritis (RA), a systematic review was conducted to assess the discrepancy of leptin in RA and its effect on immunity according to different studies. Recently, emerging data have indicated that leptin is involved in the pathological function of RA, which is common in autoimmune disorders. This review discusses the possible consequences of leptin levels in RA. Blocking the key signal pathways of leptin and inhibiting the leptin activity-like leptin antagonist may be a promising way for potential therapeutic treatment of RA at risk of detrimental effects. However, leptin was increased in patients with RA and may also regulate joint damage. Thus, more understanding of the mechanism of leptin in RA would be advantageous in the future.
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Affiliation(s)
- G Tian
- School of Health Management, Anhui Medical University, Hefei, Anhui, China
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29
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Wada N, Hirako S, Takenoya F, Kageyama H, Okabe M, Shioda S. Leptin and its receptors. J Chem Neuroanat 2014; 61-62:191-9. [PMID: 25218975 DOI: 10.1016/j.jchemneu.2014.09.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 12/11/2022]
Abstract
Leptin is mainly produced in the white adipose tissue before being secreted into the blood and transported across the blood-brain barrier. Leptin binds to a specific receptor (LepR) that has numerous subtypes (LepRa, LepRb, LepRc, LepRd, LepRe, and LepRf). LepRb, in particular, is expressed in several brain nuclei, including the arcuate nucleus, the paraventricular nucleus, and the dorsomedial, lateral and ventromedial regions of the hypothalamus. LepRb is also co-expressed with several neuropeptides, including proopiomelanocortin, neuropeptide Y, galanin, galanin-like peptide, gonadotropin-releasing hormone, tyrosine hydroxylase and neuropeptide W. Functionally, LepRb induces activation of the JAK2/ERK, /STAT3, /STAT5 and IRS/PI3 kinase signaling cascades, which are important for the regulation of energy homeostasis and appetite in mammals. In this review, we discuss the structure, genetics and distribution of the leptin receptors, and their role in cell signaling mechanisms.
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Affiliation(s)
- Nobuhiro Wada
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan
| | - Satoshi Hirako
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan
| | - Fumiko Takenoya
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan; Department of Physical Education, Hoshi University School of Pharmacy and Pharmaceutical Science, Tokyo 142-8501, Japan
| | - Haruaki Kageyama
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan; Department of Nutrition, Faculty of Health Care, Kiryu University, 606-7 Kasakakecho Azami, Midori City 379-2392, Gunma, Japan
| | - Mai Okabe
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan; Tokyo Shokuryo Dietitian Academy, Tokyo 154-0001, Japan
| | - Seiji Shioda
- Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai Shinagawa-ku, Tokyo 142-8555, Japan.
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30
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Ladyman SR, Grattan DR. JAK-STAT and feeding. JAKSTAT 2014; 2:e23675. [PMID: 24058809 PMCID: PMC3710322 DOI: 10.4161/jkst.23675] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 01/17/2013] [Accepted: 01/18/2013] [Indexed: 12/26/2022] Open
Abstract
The regulation of energy balance requires a complex system to homeostatically maintain the adult body at a precise set point. The central nervous system, particularly the hypothalamus, plays a key role in integrating a variety of signals that can relay information about the body's energy stores. As part of this system, numerous cytokines and hormones contribute to the regulation of food intake and energy homeostasis. Cytokines, and some hormones, are known to act through JAK-STAT intracellular signaling pathways. The hormone leptin, which plays a vital role in appetite regulation, signals through the JAK-STAT pathway, and it is through this involvement that the JAK-STAT pathway has become an established component in the mechanisms regulating food intake within the body. Emerging research, however, is now showing that this involvement of JAK-STAT is not limited to its activation by leptin. Furthermore, while the JAK-STAT pathway may simply act to transmit the anorectic signal of circulating factors, this intracellular signaling pathway may also become impaired when normal regulation of energy balance is disrupted. Thus, altered JAK-STAT signaling may contribute to the breakdown of the normal homeostatic mechanisms maintaining body weight in obesity.
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Affiliation(s)
- Sharon R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy; School of Medical Sciences; University of Otago; Dunedin, New Zealand
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31
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Buntin JD, Buntin L. Increased STAT5 signaling in the ring dove brain in response to prolactin administration and spontaneous elevations in prolactin during the breeding cycle. Gen Comp Endocrinol 2014; 200:1-9. [PMID: 24530808 PMCID: PMC3995851 DOI: 10.1016/j.ygcen.2014.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 01/27/2014] [Accepted: 02/05/2014] [Indexed: 01/15/2023]
Abstract
Prolactin acts on target cells in the central nervous system (CNS) to stimulate behavioral changes associated with parental care in birds, but the signaling mechanisms that mediate these actions have not been characterized. In mammals, the Janus Kinase 2-Signal Transducer and Activator of Transcription 5 (JAK2-STAT5) signaling pathway mediates many of the actions of prolactin. To assess the importance of this pathway in prolactin-sensitive target cells in the avian brain, we measured changes in activated (phosphorylated) STAT5 (pSTAT5) in the forebrain of female ring doves sampled as plasma prolactin levels change during the breeding cycle and in prolactin-treated, non-breeding females. The anatomical distribution of cells exhibiting pSTAT5 immunoreactivity in dove brain closely paralleled the distribution of prolactin receptors in this species. The density of pSTAT5 immunoreactive (pSTAT5-ir) cells was highest in the preoptic area, the suprachiasmatic, paraventricular, and ventromedial hypothalamic nuclei, the lateral and tuberal hypothalamic regions, the lateral bed nucleus of the stria terminalis, and the lateral septum. Mean pSTAT5-ir cell densities in these eight brain areas were several fold higher in breeding females during late incubation/early post-hatching when plasma prolactin levels have been observed to peak than in non-breeding females or breeding females sampled at earlier stages when prolactin titers have been reported to be lower. Similar differences were observed between prolactin-treated and vehicle-treated females in all three of the forebrain regions that were compared. We conclude that JAK2-STAT5 signaling is strongly activated in response to prolactin stimulation in the ring dove brain and could potentially mediate some of the centrally-mediated behavioral effects of this hormone.
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Affiliation(s)
- John D Buntin
- Department of Biological Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53217, United States.
| | - Linda Buntin
- Department of Biological Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53217, United States
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32
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Procaccini C, De Rosa V, Galgani M, Carbone F, La Rocca C, Formisano L, Matarese G. Role of adipokines signaling in the modulation of T cells function. Front Immunol 2013; 4:332. [PMID: 24151494 PMCID: PMC3799205 DOI: 10.3389/fimmu.2013.00332] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 10/01/2013] [Indexed: 12/15/2022] Open
Abstract
The field that links immunity and metabolism is rapidly expanding. Apparently non-immunological disorders such as obesity and type 2 diabetes have been linked to immune dysregulation, suggesting that metabolic alterations can be induced by or be consequence of an altered self-immune tolerance. In this context, adipose tissue produces and releases a variety of pro-inflammatory and anti-inflammatory factors, termed "adipokines," which can be considered as the bridge between obesity-related exogenous factors, such as nutrition and lifestyle, and the molecular events leading to metabolic syndrome, inflammatory, and/or autoimmune conditions. In obesity, increased production of most adipokines impacts on multiple functions such as appetite and energy balance, modulation of immune responses, insulin sensitivity, angiogenesis, blood pressure, lipid metabolism, and so on. This report aims to discuss some of the recent topics of adipocytokine research and their related signaling pathways, that may be of particular importance as could lead to effective therapeutic strategies for obesity-associated diseases.
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Affiliation(s)
- Claudio Procaccini
- Dipartimento di Medicina e Chirurgia, Università degli Studi di Salerno, Salerno, Italy
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy
| | - Veronica De Rosa
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy
- Unità di Neuroimmunologia, IRCCS Fondazione Santa Lucia, Roma, Italy
| | - Mario Galgani
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy
| | - Fortunata Carbone
- Dipartimento di Medicina e Chirurgia, Università degli Studi di Salerno, Salerno, Italy
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy
| | - Claudia La Rocca
- Dipartimento di Medicina e Chirurgia, Università degli Studi di Salerno, Salerno, Italy
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy
| | - Luigi Formisano
- Department of Biological, Geological and Environmental Sciences, Division of Pharmacology, University of Sannio, Benevento, Italy
| | - Giuseppe Matarese
- Dipartimento di Medicina e Chirurgia, Università degli Studi di Salerno, Salerno, Italy
- IRCCS MultiMedica, Milano, Italy
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Bosier B, Bellocchio L, Metna-Laurent M, Soria-Gomez E, Matias I, Hebert-Chatelain E, Cannich A, Maitre M, Leste-Lasserre T, Cardinal P, Mendizabal-Zubiaga J, Canduela MJ, Reguero L, Hermans E, Grandes P, Cota D, Marsicano G. Astroglial CB1 cannabinoid receptors regulate leptin signaling in mouse brain astrocytes. Mol Metab 2013; 2:393-404. [PMID: 24327955 DOI: 10.1016/j.molmet.2013.08.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 07/29/2013] [Accepted: 08/02/2013] [Indexed: 01/22/2023] Open
Abstract
Type-1 cannabinoid (CB1) and leptin (ObR) receptors regulate metabolic and astroglial functions, but the potential links between the two systems in astrocytes were not investigated so far. Genetic and pharmacological manipulations of CB1 receptor expression and activity in cultured cortical and hypothalamic astrocytes demonstrated that cannabinoid signaling controls the levels of ObR expression. Lack of CB1 receptors also markedly impaired leptin-mediated activation of signal transducers and activators of transcription 3 and 5 (STAT3 and STAT5) in astrocytes. In particular, CB1 deletion determined a basal overactivation of STAT5, thereby leading to the downregulation of ObR expression, and leptin failed to regulate STAT5-dependent glycogen storage in the absence of CB1 receptors. These results show that CB1 receptors directly interfere with leptin signaling and its ability to regulate glycogen storage, thereby representing a novel mechanism linking endocannabinoid and leptin signaling in the regulation of brain energy storage and neuronal functions.
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Key Words
- Astroglial CB1 receptors
- Astroglial leptin receptor
- CB1, type-1 cannabinoid receptor
- Cannabinoid
- Cx, cerebral cortex
- FAAH, fatty acid amide hydrolase
- GFAP, glial fibrillary acidic protein
- Glycogen
- Leptin signaling
- MGL, monoacylglycerol lipase
- ObR, leptin receptor
- ObRb, long-isoform leptin receptor
- P-STAT3, Tyr705-phosphorylated form of STAT3
- P-STAT5, Tyr694-phosphorylated form of STAT5
- STAT3 and 5
- STAT3, transducers and activators of transcription 3
- STAT5, transducers and activators of transcription 5
- VMH, ventromedial hypothalamus
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Affiliation(s)
- Barbara Bosier
- INSERM, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U862, F-33000 Bordeaux, France ; University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U862, F-33000 Bordeaux, France ; Neuropharmacology, Institute of Neurosciences, Université Catholique de Louvain, Av. Hippocrate 54, B1.54.10-10, 1200 Bruxelles, Belgium
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34
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Singireddy AV, Inglis MA, Zuure WA, Kim JS, Anderson GM. Neither signal transducer and activator of transcription 3 (STAT3) or STAT5 signaling pathways are required for leptin's effects on fertility in mice. Endocrinology 2013; 154:2434-45. [PMID: 23696567 DOI: 10.1210/en.2013-1109] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The hormone leptin is critical for the regulation of energy balance and fertility. The long-form leptin receptor (LepR) regulates multiple intracellular signaling cascades, including the classic Janus kinase-signal transducer and activator of transcription (STAT) pathways. Previous studies have shown that deletion of STAT3 or the closely related STAT5 from the brain results in an obese phenotype, but their roles in fertility regulation are not clear. This study tested whether STAT3 and STAT5 pathways of leptin signaling are required for fertility, and whether absence of one pathway might be compensated for by the other in a redundant manner. A Cre-loxP approach was used to generate 3 models of male and female transgenic mice with LepR-specific deletion of STAT3, STAT5, or both STAT3 and STAT5. Body weight, puberty onset, estrous cyclicity, and fertility were measured in all knockout (KO) mice and their control littermates. Knocking out STAT3 or both STAT3 and 5 from LepR expressing cells, but not STAT5 alone, led to significant increase in body weight. All STAT3 and STAT5 single KO mice exhibited normal puberty onset and subsequent fertility compared to their control littermates. Surprisingly, all STAT3 and STAT5 double KO mice also exhibited normal puberty onset, estrous cyclicity, and fertility, although they had severely disrupted body weight regulation. These results suggest that, although STAT3 signaling is crucial for body weight regulation, neither STAT3 nor STAT5 is required for the regulation of fertility by leptin. It remains to be determined what other signaling molecules mediate this effect of leptin, and whether they interact in a redundant manner.
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Affiliation(s)
- Amritha V Singireddy
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Medical Sciences, Dunedin 9054, New Zealand
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35
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Abstract
Leptin is secreted into the bloodstream by adipocytes and is required for the maintenance of energy homeostasis and body weight. Leptin deficiency or genetic defects in the components of the leptin signaling pathways cause obesity. Leptin controls energy balance and body weight mainly through leptin receptor b (LEPRb)-expressing neurons in the brain, particularly in the hypothalamus. These LEPRb-expressing neurons function as the first-order neurons that project to the second-order neurons located within and outside the hypothalamus, forming a neural network that controls the energy homeostasis and body weight. Multiple factors, including inflammation and endoplasmic reticulum (ER) stress, contribute to leptin resistance. Leptin resistance is the key risk factor for obesity. This review is focused on recent advance about leptin action, leptin signaling, and leptin resistance.
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36
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Velmurugan S, Russell JA, Leng G. Systemic leptin increases the electrical activity of supraoptic nucleus oxytocin neurones in virgin and late pregnant rats. J Neuroendocrinol 2013; 25:383-90. [PMID: 23298261 DOI: 10.1111/jne.12016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 11/12/2012] [Accepted: 12/20/2012] [Indexed: 12/14/2022]
Abstract
In the rat hypothalamus, fasting attenuates the expression of oxytocin and this can be reversed by exogenous leptin administration. In the present study, we investigated the effects of systemically administered leptin on the electrical activity of magnocellular neurones in the supraoptic nucleus of urethane-anaesthetised rats. In virgin female rats, systemic leptin significantly excited identified oxytocin neurones with no detected effects on the patterning of activity, as reflected by hazard function analyses. The lowest dose that was consistently effective was 100 μg/i.v., and this dose had no significant effect on vasopressin neurones. In virgin rats fasted overnight, the spontaneous firing rate of oxytocin neurones was significantly lower than in unfasted rats, although leptin had a similar excitatory effect as in unfasted rats. In late pregnant rats (days 19-21 of pregnancy), spontaneous firing rates of oxytocin neurones were higher than in virgins, and the initial response to leptin was similar to that in virgin rats, although the increase in activity was more persistent. In fasted pregnant rats, the mean spontaneous firing rate of oxytocin neurones was again lower than in unfasted rats, although leptin had no significant effect even at the higher dose of 1 mg/rat. Thus, fasting reduced the spontaneous firing rates of oxytocin neurones in nonpregnant rats, and this effect could be reversed by the excitatory effects of leptin. Pregnant rats showed some evidence of leptin resistance but only after an overnight fast.
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Affiliation(s)
- S Velmurugan
- Centre for Integrative Physiology, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
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37
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Tsou RC, Bence KK. Central regulation of metabolism by protein tyrosine phosphatases. Front Neurosci 2013; 6:192. [PMID: 23308070 PMCID: PMC3538333 DOI: 10.3389/fnins.2012.00192] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/17/2012] [Indexed: 11/13/2022] Open
Abstract
Protein tyrosine phosphatases (PTPs) are important regulators of intracellular signaling pathways via the dephosphorylation of phosphotyrosyl residues on various receptor and non-receptor substrates. The phosphorylation state of central nervous system (CNS) signaling components underlies the molecular mechanisms of a variety of physiological functions including the control of energy balance and glucose homeostasis. In this review, we summarize the current evidence implicating PTPs as central regulators of metabolism, specifically highlighting their interactions with the neuronal leptin and insulin signaling pathways. We discuss the role of a number of PTPs (PTP1B, SHP2, TCPTP, RPTPe, and PTEN), reviewing the findings from genetic mouse models and in vitro studies which highlight these phosphatases as key central regulators of energy homeostasis.
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Affiliation(s)
- Ryan C Tsou
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania Philadelphia, PA, USA
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38
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Abstract
Oxytocin neurons have a physiological role in food intake and energy balance. Central administration of oxytocin is powerfully anorexigenic, reducing food intake and meal duration. The central mechanisms underlying this effect of oxytocin have become better understood in the past few years. Parvocellular neurons of the paraventricular nucleus project to the caudal brainstem to regulate feeding via autonomic functions including the gastrointestinal vago-vagal reflex. In contrast, magnocellular neurons of the supraoptic and paraventricular nuclei release oxytocin from their dendrites to diffuse to distant hypothalamic targets involved in satiety. The ventromedial hypothalamus, for example, expresses a high density of oxytocin receptors but does not contain detectable oxytocin nerve fibers. Magnocellular neurons represent targets for the anorexigenic neuropeptide α-melanocyte stimulating hormone. In addition to homeostatic control, oxytocin may also have a role in reward-related feeding. Evidence suggests that oxytocin can selectively suppress sugar intake and that it may have a role in limiting the intake of palatable food by inhibiting the reward pathway.
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Affiliation(s)
- Nancy Sabatier
- Centre for Integrative Physiology, School of Biomedical Sciences, The University of EdinburghEdinburgh, UK
| | - Gareth Leng
- Centre for Integrative Physiology, School of Biomedical Sciences, The University of EdinburghEdinburgh, UK
| | - John Menzies
- Centre for Integrative Physiology, School of Biomedical Sciences, The University of EdinburghEdinburgh, UK
- *Correspondence: John Menzies, Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh, EH8 9XD, UK. e-mail:
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39
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Ladyman SR, Fieldwick DM, Grattan DR. Suppression of leptin-induced hypothalamic JAK/STAT signalling and feeding response during pregnancy in the mouse. Reproduction 2012; 144:83-90. [DOI: 10.1530/rep-12-0112] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hyperphagia during pregnancy, despite rising concentrations of the satiety hormone leptin, suggests that a state of leptin resistance develops. This study investigated the satiety response and hypothalamic responses to leptin during pregnancy in the mouse. Pregnant (day 13) and nonpregnant mice received an i.p. injection of either leptin or vehicle and then 24-h food intake was measured. Further groups of pregnant and nonpregnant mice were perfused 2 h after leptin or vehicle injections and brains were processed for pSTAT3 and pSTAT5 immunohistochemistry. Leptin treatment significantly decreased food intake in nonpregnant mice. In pregnant mice, however, leptin treatment did not suppress food intake, indicating a state of leptin resistance. In the arcuate nucleus, leptin treatment increased the number of cells positive for pSTAT3, a marker of leptin activity, to a similar degree in both nonpregnant and pregnant mice. In the ventromedial nucleus (VMN), the leptin-induced increase in pSTAT3-positive cell number was significantly reduced in pregnant mice compared to that in nonpregnant mice. In nonpregnant mice, leptin treatment had no effect on the number of pSTAT5-positive cells, suggesting that in this animal model, leptin does not act through STAT5. In pregnant mice, basal levels of pSTAT5 were higher than in nonpregnant mice, and leptin treatment led to a decrease in the number of pSTAT5-positive cells in the hypothalamus. Overall, these results demonstrate that during pregnancy in the mouse, a state of leptin resistance develops, and this is associated with a reduced sensitivity of the VMN to leptin.
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40
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Morton GJ, Schwartz MW. Leptin and the central nervous system control of glucose metabolism. Physiol Rev 2011; 91:389-411. [PMID: 21527729 DOI: 10.1152/physrev.00007.2010] [Citation(s) in RCA: 210] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The regulation of body fat stores and blood glucose levels is critical for survival. This review highlights growing evidence that leptin action in the central nervous system plays a key role in both processes. Investigation into underlying mechanisms has begun to clarify the physiological role of leptin in the control of glucose metabolism and raises interesting new possibilities for the treatment of diabetes and related disorders.
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Affiliation(s)
- Gregory J Morton
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington 98195, USA.
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41
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Sahu A. Intracellular leptin-signaling pathways in hypothalamic neurons: the emerging role of phosphatidylinositol-3 kinase-phosphodiesterase-3B-cAMP pathway. Neuroendocrinology 2011; 93:201-10. [PMID: 21464566 PMCID: PMC3130491 DOI: 10.1159/000326785] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 02/24/2011] [Indexed: 01/02/2023]
Abstract
Leptin is secreted primarily by fat cells and acts centrally, particularly in the hypothalamus, to reduce food intake and body weight. Besides the classical JAK2 (Janus kinase-2)-STAT3 (signal transducer and activator of transcription-3) pathway, several non-STAT3 pathways play an important role in mediating leptin signaling in the hypothalamus. We have demonstrated that leptin action in the hypothalamus is mediated by an insulin-like signaling pathway involving stimulation of PI3K (phosphatidylinositol-3 kinase) and PDE3B (phosphodiesterase-3B), and reduction in cAMP levels, and that a PI3K-PDE3B-cAMP pathway interacting with the JAK2-STAT3 pathway constitutes a critical component of leptin signaling in the hypothalamus. It appears that defective regulation of multiple signaling pathways in the hypothalamus causes central leptin resistance, a major cause of obesity. In this regard, we have shown that leptin resistance in hypothalamic neurons following chronic central infusion of this hormone is associated with a defect in the PI3K-PDE3B-cAMP, and not due to compromised signaling in the JAK2-STAT3 pathway. Similarly, the PI3K, but not the STAT3, pathway is impaired in the hypothalamus during the development of diet-induced obesity. Additionally, our recent work suggests that suppressor of cytokine signaling-3 negatively regulates the PI3K pathway of leptin signaling in the hypothalamus, a mechanism expected to play a significant role in diet-induced obesity. Together, the PI3K-PDE3B-cAMP pathway appears to emerge as a major mechanism of leptin signaling in the hypothalamus in regulating energy balance.
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Affiliation(s)
- Abhiram Sahu
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Magee-Womens Research Institute, Pittsburgh, PA 15213, USA.
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42
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Caquineau C, Douglas AJ, Leng G. Effects of cholecystokinin in the supraoptic nucleus and paraventricular nucleus are negatively modulated by leptin in 24-h fasted lean male rats. J Neuroendocrinol 2010; 22:446-52. [PMID: 20163516 PMCID: PMC2948420 DOI: 10.1111/j.1365-2826.2010.01982.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 01/27/2010] [Accepted: 02/09/2010] [Indexed: 11/30/2022]
Abstract
Cholecystokinin (CCK) and leptin are two important satiety factors that are considered to act in synergy to reduce meal size. Peripheral injection of CCK activates neurones in several hypothalamic nuclei, including the supraoptic (SON) and paraventricular (PVN) nuclei and neurones in the brainstem of fed rats. We investigated whether peripheral leptin would modulate the effects of CCK on neuronal activity in the hypothalamus and brainstem of fasted rats by investigating Fos expression in the PVN, SON, arcuate nucleus, ventromedial hypothalamus (VMH), dorsomedial hypothalamus (DMH), area postrema (AP) and the nucleus tractus solitarii (NTS). Male rats, fasted for 24 h, received either one i.p. injection of vehicle, leptin or CCK-8 alone, or received one injection of vehicle or leptin before an i.p. injection of CCK-8. We found that CCK increased Fos expression in the PVN and SON as well as in the NTS and AP, but had no effect on Fos expression in the arcuate nucleus, VMH or DMH compared to vehicle. Leptin injected alone significantly increased Fos expression in the arcuate nucleus but had no effect on Fos expression in the VMH, DMH, SON, PVN, AP or NTS compared to vehicle. Fos expression was significantly increased in the AP in rats injected with both leptin and CCK compared to rats injected with vehicle and CCK. Unexpectedly, there was significantly less Fos expression in the PVN and SON of fasted rats injected with leptin and CCK than in rats injected with vehicle and CCK, suggesting that leptin attenuated CCK-induced Fos expression in the SON and PVN. However, Fos expression in the NTS was similar in fasted rats injected with vehicle and CCK or with leptin and CCK. Taken together, these results suggest that leptin dampens the effects of CCK on Fos expression in the SON and PVN, independently from NTS pathways, and this may reflect a direct action on magnocellular neurones.
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Affiliation(s)
- C Caquineau
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK.
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43
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Brown RS, Kokay IC, Herbison AE, Grattan DR. Distribution of prolactin-responsive neurons in the mouse forebrain. J Comp Neurol 2010; 518:92-102. [DOI: 10.1002/cne.22208] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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44
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Abstract
The brain controls energy homeostasis and body weight by integrating various metabolic signals. Leptin, an adipose-derived hormone, conveys critical information about peripheral energy storage and availability to the brain. Leptin decreases body weight by both suppressing appetite and promoting energy expenditure. Leptin directly targets hypothalamic neurons, including AgRP and POMC neurons. These leptin-responsive neurons widely connect to other neurons in the brain, forming a sophisticated neurocircuitry that controls energy intake and expenditure. The anorexigenic actions of leptin are mediated by LEPRb, the long form of the leptin receptor, in the hypothalamus. LEPRb activates both JAK2-dependent and -independent pathways, including the STAT3, PI 3-kinase, MAPK, AMPK, and mTOR pathways. These pathways act coordinately to form a network that fully mediates leptin response. LEPRb signaling is regulated by both positive (e.g., SH2B1) and negative (e.g., SOCS3 and PTP1B) regulators and by endoplasmic reticulum stress. Leptin resistance, a primary risk factor for obesity, likely results from impairment in leptin transport, LEPRb signaling, and/or the neurocircuitry of energy balance.
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Affiliation(s)
- David L Morris
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Mchigan 48109-0622, USA
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45
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Villanueva EC, Myers MG. Leptin receptor signaling and the regulation of mammalian physiology. Int J Obes (Lond) 2009; 32 Suppl 7:S8-12. [PMID: 19136996 DOI: 10.1038/ijo.2008.232] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The adipocyte-derived hormone, leptin, signals the status of body energy stores to the central nervous system to regulate appetite and energy expenditure. A specific long-form leptin receptor (LepRb), a type I cytokine receptor, mediates leptin action on LepRb-expressing neurons in the brain. Leptin binding to LepRb activates the associated Janus kinase-2 (Jak2) tyrosine kinase to promote the phosphorylation of Jak2 and three residues on LepRb; each of these sites mediates a distinct aspect of downstream LepRb signaling, with differing physiologic functions. Tyr(1138) --> STAT3 signaling suppresses feeding, but is not required for a number of other leptin actions. Tyr(985) binds SH2-containing tyrosine phosphatase-2 and suppressor of cytokine signaling-3 and primarily mediates the attenuation of LepRb signaling in vivo. The role for Tyr(1077), the major regulator of signal transducer and activator of transcription-5 (STAT5) during leptin signaling, in the physiologic response to leptin remains unclear, although the obese phenotype of animals deleted for STAT5 in the brain suggests the potential importance of this signaling pathway. Leptin also modulates a number of other signaling pathways in the brain, including PI 3-kinase, mammalian target of rapamycin and AMP-dependent protein kinase; the pathways by which leptin controls these signals remain unclear, however, and may involve some indirect mechanisms. Important issues regarding leptin action and LepRb signaling in the future include not only the more thorough analysis of intracellular signaling pathways, but the neural substrate by which leptin acts, as most major populations of LepRb neurons remain poorly studied.
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Affiliation(s)
- E C Villanueva
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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46
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Effect of leptin on cytotrophoblast proliferation and invasion. ACTA ACUST UNITED AC 2009; 29:631-6. [DOI: 10.1007/s11596-009-0519-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Indexed: 10/19/2022]
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47
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Watanabe Y, Ikegawa M, Naruse Y, Tanaka M. A novel splicing variant form suppresses the activity of full-length signal transducer and activator of transcription 5A. FEBS J 2009; 276:6312-23. [PMID: 19788420 DOI: 10.1111/j.1742-4658.2009.07339.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Signal transducers and activators of transcription (STATs) regulate a variety of cellular functions, including differentiation and proliferation. STAT3 and STAT5 are known to play important roles in brain processes, such as energy homeostasis and neuronal development. We isolated a novel splicing variant of STAT5A from a cDNA library of the mouse brainstem. This variant, STAT5A_DeltaE18, lacked exon 18 and caused a frameshift in the C-terminus, resulting in deletion of a tyrosine phosphorylation site and a transactivation domain. Although the frameshift region had no characteristic motifs, it was highly serine/threonine-rich and contained a short proline-rich sequence. Expression of STAT5A_DeltaE18 was detected in the mouse brainstem, lung and thymus, but not in the mouse cerebrum or cerebellum. We developed a specific antibody against STAT5A_DeltaE18 and investigated the intracellular localization of this variant. STAT5A_DeltaE18 showed dot-like structures in the cytoplasm and could not translocate into the nucleus after prolactin treatment. STAT5A_DeltaE18 showed a strong tendency to aggregate, which led to coaggregation with STAT5A_full-length. This coaggregation inhibited the nuclear transport of STAT5A and suppressed prolactin-induced activation of STAT5A.
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Affiliation(s)
- Yoshihisa Watanabe
- Department of Cell Biology, Research Institute for Neurological Diseases and Geriatrics, Kyoto Prefectural University of Medicine, Japan
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48
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Quennell JH, Mulligan AC, Tups A, Liu X, Phipps SJ, Kemp CJ, Herbison AE, Grattan DR, Anderson GM. Leptin indirectly regulates gonadotropin-releasing hormone neuronal function. Endocrinology 2009; 150:2805-12. [PMID: 19179437 PMCID: PMC2732287 DOI: 10.1210/en.2008-1693] [Citation(s) in RCA: 260] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adipose-derived hormone leptin communicates information about metabolic status to the hypothalamic GnRH neuronal system. It is unclear whether leptin can act directly on GnRH neurons. To examine this, we used three approaches. First, the presence of leptin-induced signal transducer and activator of transcription-3 activation was examined in GnRH neurons in male and female rats. Intracerebroventricular treatment with 4 mug leptin-induced robust signal transducer and activator of transcription-3 expression within the anteroventral periventricular nucleus but not in GnRH neurons. Second, fertility was assessed in male and female CRE-loxP transgenic mice with conditional leptin receptor (Lepr) deletion from either all forebrain neurons or GnRH neurons only. Forebrain neuron LEPR deletion prevented the onset of puberty resulting in infertility in males and females and blocked estradiol-induced LH surge. However, mice with GnRH neuron-selective Lepr deletion exhibited normal fertility apart from a slight puberty delay in males. Lastly, the highly sensitive technique of single-cell nested PCR was used to test for Lepr transcript presence in individual GnRH neurons, identified in situ using GnRH-green fluorescent protein transgenics. Whereas 75% of positive control (proopiomelanocortin) neurons contained Lepr mRNA, no (none of 18) GnRH neurons were Lepr mRNA positive. Collectively, these results show that leptin does not act directly on GnRH neurons in rats and mice. Leptin appears to regulate GnRH function via forebrain neurons that are afferent to GnRH because forebrain neuronal LEPR deletion caused infertility. The location and phenotype of these leptin-responsive neurons remains to be elucidated.
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Affiliation(s)
- Janette H Quennell
- Department of Anatomy and Structural Biology, Centre for Neuroendocrinology, University of Otago School of Medical Sciences, Dunedin, New Zealand
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49
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Rummel C, Inoue W, Sachot C, Poole S, Hübschle T, Luheshi GN. Selective contribution of interleukin-6 and leptin to brain inflammatory signals induced by systemic LPS injection in mice. J Comp Neurol 2008; 511:373-95. [DOI: 10.1002/cne.21850] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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50
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Barnes MJ, Primeaux SD, Bray GA. Food deprivation increases the mRNA expression of micro-opioid receptors in the ventral medial hypothalamus and arcuate nucleus. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1385-90. [PMID: 18768770 DOI: 10.1152/ajpregu.00030.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Activation of micro-opioid receptors makes animals hyperphagic and increases their preference for a high-fat diet. Previous studies have suggested that this receptor population plays a role in mediating the hyperphagia that is associated with food deprivation. In this paper, we tested the hypothesis that food deprivation will increase the expression of micro-opioid receptors in the ventral medial hypothalamus and arcuate nucleus (VMH/ARC). Food deprivation resulted in a significant increase in the mRNA expression of micro-opioid receptors in the VMH/ARC and the lateral hypothalamus (LH) after 48 h of fasting but not after 24 or 12 h of fasting in either the light or dark. We did not observe a change in the mRNA expression of kappa- or delta-opioid receptors after food deprivation. When food-deprived animals were given a choice between a low-fat diet and a high-fat diet, they were hyperphagic and consumed significantly more of the high-fat diet. When the micro-opioid receptors were blocked with beta-funaltrexamine (selective mu-opioid receptor antagonist), prior to giving food-deprived animals access to both a low-fat and high-fat diet, it significantly decreased the percentage of high-fat diet consumed. These data demonstrate that hypothalamic micro-opioid receptors may contribute to the hyperphagia and increased preference for a high-fat diet that is associated with food deprivation.
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Affiliation(s)
- Maria J Barnes
- Dietary Obesity Laboratory, Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA.
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