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Hekim MG, Kelestemur MM, Bulmus FG, Bilgin B, Bulut F, Gokdere E, Ozdede MR, Kelestimur H, Canpolat S, Ozcan M. Asprosin, a novel glucogenic adipokine: a potential therapeutic implication in diabetes mellitus. Arch Physiol Biochem 2023; 129:1038-1044. [PMID: 33663304 DOI: 10.1080/13813455.2021.1894178] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022]
Abstract
OBJECTIVES We aimed to investigate the effects of asprosin on diabetes with a focus on serum glucose, irisin, ghrelin, leptin levels and hepatic levels of triglycerides (TG), cholesterol, low-density lipoprotein (LDL). METHODS Asprosin (10 µg/kg) was administered intraperitoneally four times at 3-day intervals and then blood and hepatic parameters above mentioned were investigated in control and diabetic mice. RESULTS The administration of asprosin increased blood glucose level in healthy animals (p = .05) whereas it did not change blood glucose level in diabetic animals. In addition, while asprosin decreased irisin level and increased ghrelin level, it did not change leptin level in diabetic mice. Therewithal, asprosin decreased the increasing levels in hepatic TG, cholesterol, and LDL in diabetic mice. CONCLUSIONS Our novel findings implicate that asprosin may be a target molecule in preventing the development and complications of diabetes.
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Affiliation(s)
| | | | - Funda Gulcu Bulmus
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Balikesir University, Balikesir, Turkey
| | - Batuhan Bilgin
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Ferah Bulut
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Ebru Gokdere
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | | | - Haluk Kelestimur
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Sinan Canpolat
- Department of Physiology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Mete Ozcan
- Department of Biophysics, Faculty of Medicine, Firat University, Elazig, Turkey
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2
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Jiménez-Cortegana C, Hontecillas-Prieto L, García-Domínguez DJ, Zapata F, Palazón-Carrión N, Sánchez-León ML, Tami M, Pérez-Pérez A, Sánchez-Jiménez F, Vilariño-García T, de la Cruz-Merino L, Sánchez-Margalet V. Obesity and Risk for Lymphoma: Possible Role of Leptin. Int J Mol Sci 2022; 23:15530. [PMID: 36555171 PMCID: PMC9779026 DOI: 10.3390/ijms232415530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.
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Affiliation(s)
- Carlos Jiménez-Cortegana
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY 10065, USA
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Lourdes Hontecillas-Prieto
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Daniel J. García-Domínguez
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Fernando Zapata
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Natalia Palazón-Carrión
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - María L. Sánchez-León
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Malika Tami
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Antonio Pérez-Pérez
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Flora Sánchez-Jiménez
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Teresa Vilariño-García
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Luis de la Cruz-Merino
- Oncology Service, Department of Medicines, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
| | - Víctor Sánchez-Margalet
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, Virgen Macarena University Hospital, University of Seville, 41009 Seville, Spain
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Conde K, Kulyk D, Vanschaik A, Daisey S, Rojas C, Wiersielis K, Yasrebi A, Degroat TJ, Sun Y, Roepke TA. Deletion of Growth Hormone Secretagogue Receptor in Kisspeptin Neurons in Female Mice Blocks Diet-Induced Obesity. Biomolecules 2022; 12:1370. [PMID: 36291579 PMCID: PMC9599822 DOI: 10.3390/biom12101370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/16/2022] [Accepted: 09/22/2022] [Indexed: 01/19/2023] Open
Abstract
The gut peptide, ghrelin, mediates energy homeostasis and reproduction by acting through its receptor, growth hormone secretagogue receptor (GHSR), expressed in hypothalamic neurons in the arcuate (ARC). We have shown 17β-estradiol (E2) increases Ghsr expression in Kisspeptin/Neurokinin B/Dynorphin (KNDy) neurons, enhancing sensitivity to ghrelin. We hypothesized that E2-induced Ghsr expression augments KNDy sensitivity in a fasting state by elevating ghrelin to disrupt energy expenditure in females. We produced a Kiss1-GHSR knockout to determine the role of GHSR in ARC KNDy neurons. We found that changes in ARC gene expression with estradiol benzoate (EB) treatment were abrogated by the deletion of GHSR and ghrelin abolished these differences. We also observed changes in metabolism and fasting glucose levels. Additionally, knockouts were resistant to body weight gain on a high fat diet (HFD). Behaviorally, we found that knockouts on HFD exhibited reduced anxiety-like behavior. Furthermore, knockouts did not refeed to the same extent as controls after a 24 h fast. Finally, in response to cold stress, knockout females had elevated metabolic parameters compared to controls. These data indicate GHSR in Kiss1 neurons modulate ARC gene expression, metabolism, glucose homeostasis, behavior, and thermoregulation, illustrating a novel mechanism for E2 and ghrelin to control Kiss1 neurons.
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Affiliation(s)
- Kristie Conde
- Graduate Program in Neuroscience, Rutgers University Robert Wood Johnson Medical School, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Danielle Kulyk
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Allison Vanschaik
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Sierra Daisey
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Catherine Rojas
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Kimberly Wiersielis
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Ali Yasrebi
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Thomas J. Degroat
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Yuxiang Sun
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Troy A. Roepke
- Graduate Program in Neuroscience, Rutgers University Robert Wood Johnson Medical School, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- Rutgers Center for Lipid Research, the Center for Nutrition, Microbiome, and Health, and the New Jersey Institute of Food, Nutrition, and Health, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
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Mahmoudi F, Haghighat Gollo K. Influences of Serotonin Hydrochloride on Adiponectin, Ghrelin and KiSS1 Genes Expression. Galen Med J 2021; 9:e1767. [PMID: 34466589 PMCID: PMC8343906 DOI: 10.31661/gmj.v9i0.1767] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/22/2019] [Accepted: 02/03/2020] [Indexed: 11/16/2022] Open
Abstract
Background:
Serotonin and kisspeptin stimulates gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) release while ghrelin and adiponectin inhibit them. In the present experimental study, the effects of central injection of serotonin were investigated on LH concentration, KiSS1, adiponectin, and ghrelin genes expression.
Materials and Methods: Fifteen Wistar male rats in three groups received saline or serotonin hydrochloride via the third cerebral ventricle. Blood samples were collected via the tail vein. Serum LH concentration and relative gene expression were evaluated by radioimmunoassay and real-time polymerase chain reaction method, respectively. Results:
Serotonin significantly increased the mean serum LH concentration and KiSS1 gene expression levels compared to the saline group. Serotonin significantly decreased the mean ghrelin and adiponectin genes expression levels compared to the saline group.
Conclusion: The serotonergic pathway may have stimulatory effects on hypothalamic kisspeptin synthesis, partly via inhibiting hypothalamic ghrelin and adiponectin neural activity.
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Affiliation(s)
- Fariba Mahmoudi
- Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
- Correspondence to: Fariba Mahmoudi, Faculty of Physiology, Ph. D. Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran Telephone Number: 09144190422 Email Address:
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Hagiwara D, Tochiya M, Azuma Y, Tsumura T, Hodai Y, Kawaguchi Y, Miyata T, Kobayashi T, Sugiyama M, Onoue T, Takagi H, Ito Y, Iwama S, Suga H, Banno R, Arima H. Arginine vasopressin-Venus reporter mice as a tool for studying magnocellular arginine vasopressin neurons. Peptides 2021; 139:170517. [PMID: 33647312 DOI: 10.1016/j.peptides.2021.170517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/20/2022]
Abstract
Arginine vasopressin (AVP) synthesized in the magnocellular neurons of the hypothalamus is transported through their axons and released from the posterior pituitary into the systemic circulation to act as an antidiuretic hormone. AVP synthesis and release are precisely regulated by changes in plasma osmolality. Magnocellular AVP neurons receive innervation from osmosensory and sodium-sensing neurons, but previous studies showed that AVP neurons per se are osmosensitive as well. In the current study, we made AVP-Venus reporter mice and showed that Venus was expressed exclusively in AVP neurons and was upregulated under water deprivation. In hypothalamic organotypic cultures from the AVP-Venus mice, Venus-labeled AVP neurons in the supraoptic and paraventricular nuclei survived for 1 month, and Venus expression was upregulated by forskolin. Furthermore, in dissociated Venus-labeled magnocellular neurons, treatment with NaCl, but not with mannitol, decreased Venus fluorescence in the soma of the AVP neurons. Thus, Venus expression in AVP-Venus transgenic mice, as well as in primary cultures, faithfully showed the properties of intrinsic AVP expression. These findings indicate that AVP-Venus mice as well as the primary hypothalamic cultures could be useful for studying magnocellular AVP neurons.
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Affiliation(s)
- Daisuke Hagiwara
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Masayoshi Tochiya
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Yoshinori Azuma
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Tetsuro Tsumura
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Yuichi Hodai
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Yohei Kawaguchi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Takashi Miyata
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Tomoko Kobayashi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Mariko Sugiyama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Takeshi Onoue
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Hiroshi Takagi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Yoshihiro Ito
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Shintaro Iwama
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Hidetaka Suga
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Ryoichi Banno
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan; Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, 464-8601, Japan
| | - Hiroshi Arima
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
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6
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Kim S, Nam Y, Shin SJ, Park YH, Jeon SG, Kim JI, Kim MJ, Moon M. The Potential Roles of Ghrelin in Metabolic Syndrome and Secondary Symptoms of Alzheimer's Disease. Front Neurosci 2020; 14:583097. [PMID: 33071750 PMCID: PMC7543232 DOI: 10.3389/fnins.2020.583097] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022] Open
Abstract
Although the major causative factors of Alzheimer's disease (AD) are the accumulation of amyloid β and hyperphosphorylated tau, AD can also be caused by metabolic dysfunction. The major clinical symptom of AD is cognitive dysfunction. However, AD is also accompanied by various secondary symptoms such as depression, sleep-wake disturbances, and abnormal eating behaviors. Interestingly, the orexigenic hormone ghrelin has been suggested to have beneficial effects on AD-related metabolic syndrome and secondary symptoms. Ghrelin improves lipid distribution and alters insulin sensitivity, effects that are hypothesized to delay the progression of AD. Furthermore, ghrelin can relieve depression by enhancing the secretion of hormones such as serotonin, noradrenaline, and orexin. Moreover, ghrelin can upregulate the expression of neurotrophic factors such as brain-derived neurotrophic factor and modulate the release of proinflammatory cytokines such as tumor necrosis factor α and interleukin 1β. Ghrelin alleviates sleep-wake disturbances by increasing the levels of melatonin, melanin-concentrating hormone. Ghrelin reduces the risk of abnormal eating behaviors by increasing neuropeptide Y and γ-aminobutyric acid. In addition, ghrelin increases food intake by inhibiting fatty acid biosynthesis. However, despite the numerous studies on the role of ghrelin in the AD-related pathology and metabolic disorders, there are only a few studies that investigate the effects of ghrelin on secondary symptoms associated with AD. In this mini review, our purpose is to provide the insights of future study by organizing the previous studies for the role of ghrelin in AD-related pathology and metabolic disorders.
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Affiliation(s)
- Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Yunkwon Nam
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Soo Jung Shin
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Yong Ho Park
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Seong Gak Jeon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea.,Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Jin-Il Kim
- Department of Nursing, College of Nursing, Jeju National University, Jeju-si, South Korea
| | - Min-Jeong Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon, South Korea
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7
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Lis M, Stańczykiewicz B, Liśkiewicz P, Misiak B. Impaired hormonal regulation of appetite in schizophrenia: A narrative review dissecting intrinsic mechanisms and the effects of antipsychotics. Psychoneuroendocrinology 2020; 119:104744. [PMID: 32534330 DOI: 10.1016/j.psyneuen.2020.104744] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/25/2020] [Accepted: 05/30/2020] [Indexed: 12/14/2022]
Abstract
Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects. Early hormonal alterations that might be associated with intrinsic mechanisms include low levels of leptin and glucagon-like peptide-1 (GLP-1) together with elevated insulin levels in first-episode psychosis (FEP) patients. However, evidence regarding low GLP-1 levels in FEP patients is based on one large study. In turn, multiple-episode schizophrenia patients show elevated levels of insulin, leptin and orexin A together with decreased levels of adiponectin. In addition, patients receiving olanzapine may present with low ghrelin levels. Post mortem studies have also demonstrated reduced number of neuropeptide Y neurons in the prefrontal cortex of patients with schizophrenia. Treatment with certain second-generation antipsychotics may also point to these alterations. Although our understanding of hormonal regulation of appetite in schizophrenia has largely been improved, several limitations and directions for future studies need to be addressed. This is of particular importance since several novel pharmacological interventions for obesity and diabetes have already been developed and translation of these developments to the treatment of cardiometabolic comorbidities in schizophrenia patients is needed.
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Affiliation(s)
- Michał Lis
- Clinical Department of Internal Diseases, Endocrinology and Diabetology, The Central Clinical Hospital of the Ministry of the Interior in Warsaw, Wołoska 137 Street, 02-507 Warsaw, Poland
| | - Bartłomiej Stańczykiewicz
- Department of Nervous System Diseases, Wroclaw Medical University, Bartla 5 Street, 51-618, Wroclaw, Poland
| | - Paweł Liśkiewicz
- Department of Psychiatry, Pomeranian Medical University, Broniewskiego 26 Street, 71-460, Szczecin, Poland
| | - Błażej Misiak
- Department of Genetics, Wroclaw Medical University, Marcinkowskiego 1 Street, 50-368 Wroclaw, Poland.
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8
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Fibrillin-1 and fibrillin-1-derived asprosin in adipose tissue function and metabolic disorders. J Cell Commun Signal 2020; 14:159-173. [PMID: 32279186 DOI: 10.1007/s12079-020-00566-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/28/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
The extracellular matrix microenvironment of adipose tissue is of critical importance for the differentiation, remodeling and function of adipocytes. Fibrillin-1 is one of the main components of microfibrils and a key player in this process. Furin processing of profibrillin-1 results in mature fibrillin-1 and releases the C-terminal propeptide as a circulating hunger hormone, asprosin. Mutations in the fibrillin-1 gene lead to adipose tissue dysfunction and causes Marfan syndrome, marfanoid progeroid lipodystrophy syndrome, and neonatal progeroid syndrome. Increased TGF-β signaling, altered mechanical properties and impaired adipogenesis are potential causes of adipose tissue dysfunction, mediated through deficient microfibrils. Circulating asprosin on the other hand is secreted primarily by white adipose tissue under fasting conditions and in obesity. It increases hepatic glucose production and drives insulin secretion and appetite stimulation through inter-organ cross talk. This review discusses the metabolic consequences of fibrillin-1 and fibrillin-1-derived asprosin in pathological conditions. Understanding the dynamic role of fibrillin-1 in the adipose tissue milieu and of circulating asprosin in the body can provide novel mechanistic insights into how fibrillin-1 may contribute to metabolic syndrome. This could lead to new management regimens of patients with metabolic disease.
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9
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Sefton C, Davies A, Allen TJ, Wray JR, Shoop R, Adamson A, Humphreys N, Coll AP, White A, Harno E. Metabolic Abnormalities of Chronic High-Dose Glucocorticoids Are Not Mediated by Hypothalamic AgRP in Male Mice. Endocrinology 2019; 160:964-978. [PMID: 30794724 PMCID: PMC6444294 DOI: 10.1210/en.2019-00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022]
Abstract
Glucocorticoids are potent and widely used medicines but often cause metabolic side effects. A murine model of corticosterone treatment resulted in increased hypothalamic expression of the melanocortin antagonist AgRP in parallel with obesity and hyperglycemia. We investigated how these adverse effects develop over time, with particular emphasis on hypothalamic involvement. Wild-type and Agrp-/- male mice were treated with corticosterone for 3 weeks. Phenotypic, biochemical, protein, and mRNA analyses were undertaken on central and peripheral tissues, including white and brown adipose tissue, liver, and muscle, to determine the metabolic consequences. Corticosterone treatment induced hyperphagia within 1 day in wild-type mice, which persisted for 3 weeks. Despite this early increase in food intake, the body weight only started to increase after 10 days. Hyperinsulinemia occurred at day 1. Also, although after 2 days, alterations were present in the genes often associated with insulin resistance in several peripheral tissues, hyperglycemia only developed at 3 weeks. Throughout, sustained elevation in hypothalamic Agrp expression was present. Mice with Agrp deleted [using clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, Agrp-/-] were partially protected against corticosterone-induced hyperphagia. However, Agrp-/- mice still had corticosterone-induced increases in body weight and adiposity similar to those of the Agrp+/+ mice. Loss of Agrp did not diminish corticosterone-induced hyperinsulinemia or correct changes in hepatic gluconeogenic genes. Chronic glucocorticoid treatment in mice mimics many of the metabolic side effects seen in patients and leads to a robust increase in Agrp. However, AgRP does not appear to be responsible for most of the glucocorticoid-induced adverse metabolic effects.
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Affiliation(s)
- Charlotte Sefton
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Alison Davies
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Tiffany-Jayne Allen
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Jonathan R Wray
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Rosemary Shoop
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Antony Adamson
- Manchester Transgenic Unit, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Neil Humphreys
- Manchester Transgenic Unit, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Anthony P Coll
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
- Correspondence : Erika Harno, PhD, or Anne White, PhD, Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, 3.016 AV Hill Building, Manchester M13 9PT, United Kingdom. E-mail: or ; or Anthony P. Coll, PhD, University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge CB2 0QQ, United Kingdom. E-mail:
| | - Anne White
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
- Correspondence : Erika Harno, PhD, or Anne White, PhD, Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, 3.016 AV Hill Building, Manchester M13 9PT, United Kingdom. E-mail: or ; or Anthony P. Coll, PhD, University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge CB2 0QQ, United Kingdom. E-mail:
| | - Erika Harno
- Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
- Correspondence : Erika Harno, PhD, or Anne White, PhD, Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, 3.016 AV Hill Building, Manchester M13 9PT, United Kingdom. E-mail: or ; or Anthony P. Coll, PhD, University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge CB2 0QQ, United Kingdom. E-mail:
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10
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Chouzouris TM, Dovolou E, Rekkas CA, Georgoulias P, Athanasiou LV, Amiridis GS. A study on ghrelin and LH secretion after short fasting and on ghrelin levels at perioestrual period in dairy cattle. Reprod Domest Anim 2018; 54:91-99. [PMID: 30171634 DOI: 10.1111/rda.13321] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/13/2018] [Indexed: 12/19/2022]
Abstract
In two experiments, we studied (a) the changes of LH secretion in heifers under different feeding schedules and (b) total ghrelin concentration at oestrus in cows and heifers. In experiment one, synchronized heifers were allocated in three groups (R, regularly fed controls; F, fasted; and F-F fasted-fed). One day after the completion of the oestrous induction protocol, group F and F-F animals stayed without feed for 24 hr; thereafter, feed was provided to R and F-F cattle; 2 hr later, GnRH was administered to all animals. Blood samples were collected for ghrelin, progesterone, LH and cortisol concentrations. Fasting caused increased ghrelin concentrations in groups F and F-F, while in response to GnRH, LH surge was significantly attenuated in groups F and F-F compared to R. In experiment 2, lactating cows and heifers were used. On day 9 of a synchronized cycle, PGF2α was administered, and blood samples were collected twice daily until the third day after oestrus and analysed for progesterone, estradiol, ghrelin, glucose and BHBA concentrations. No difference was recorded between groups in steroids and BHBA concentrations. In comparison to mid-luteal values, ghrelin concentrations significantly increased at perioestrual period in cows, but not in heifers. This study provides evidence that starving-induced elevated ghrelin concentrations can have suppressing effect on LH secretion, even after ghrelin's restoration to basal values and that during oestrus, ghrelin secretion is differently regulated in cows and heifers, likely being independent from oestradiol concentrations. Further research is required to identify the determining factors that drive the different regulation of ghrelin secretion in cows and heifers.
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Affiliation(s)
- Thomas Markos Chouzouris
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Eleni Dovolou
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | | | - Panagiotis Georgoulias
- Department of Nuclear Medicine, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Lambrini V Athanasiou
- Department of Medicine, Veterinary Faculty, University of Thessaly, Karditsa, Greece
| | - Georgios S Amiridis
- Department of Obstetrics and Reproduction, Veterinary Faculty, University of Thessaly, Karditsa, Greece
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11
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Targeting AgRP neurons to maintain energy balance: Lessons from animal models. Biochem Pharmacol 2018; 155:224-232. [PMID: 30012460 DOI: 10.1016/j.bcp.2018.07.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/12/2018] [Indexed: 01/19/2023]
Abstract
The current obesity epidemic is a major worldwide health and economic burden. In the modern environment, an increase in the intake of high-fat and high-sugar foods plays a crucial role in the development of obesity by disrupting the mechanisms governing food intake and energy balance. Food intake and whole-body energy balance are regulated by the central nervous system through a sophisticated neuronal network located mostly in the hypothalamus. In particular, the hypothalamic arcuate nucleus (ARC) is a fundamental center that senses hormonal and nutrient-related signals informing about the energy state of the organism. The ARC contains two small, defined populations of neurons with opposite functions: anorexigenic proopiomelanocortin (POMC)-expressing neurons and orexigenic Agouti-related protein (AgRP)-expressing neurons. AgRP neurons, which also co-produce neuropeptide Y (NPY) and γ-Aminobutyric acid (GABA), are involved in an increase in hunger and a decrease in energy expenditure. In this review, we summarize the key findings from the most common animal models targeting AgRP neurons and the tools used to discern the role of this specific neuronal population in the control of peripheral metabolism, appetite, feeding-related behavior, and other complex behaviors. We also discuss how knowledge gained from these studies has revealed new pathways and key proteins that could be potential therapeutic targets to reduce appetite and food addictions in obesity and other diseases.
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12
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Functional Interrogation of the AgRP Neural Circuits in Control of Appetite, Body Weight, and Behaviors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1090:1-16. [PMID: 30390282 DOI: 10.1007/978-981-13-1286-1_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neurons expressing agouti-related protein (AgRP), the so-called hunger neurons, protect mammals from starvation by promoting food-seeking behaviors (Trends Neurosci 36:504-512, 2013). Now an increasing amount of evidence show that these hunger-sensing neurons not only motivate animals to forage and ingest food but also help conserve energy by inhibiting innate processes that demand large amounts of energy such as growth, reproduction, and stress response. It has further been perceived that AgRP neurons transmit signals with negative valence to reward and cognitive centers so as to engage the motivational behavior toward seeking and obtaining foods (Physiol Behav 190:34-42, 2017). Recent advancement in genome editing and neurotechniques unleashed an escalated research of uniquely defined neuronal populations and neural circuits underlying the behavioral regulation of body weight and food responses (Nat Biotechnol 32:347-355, 2014; Proc Natl Acad Sci 113, 2016). In this chapter we will review literatures describing the functional organization of the AgRP circuit and its correlative signaling components that influence ingestive, foraging, motivational, and cognitive responses, a framework that reshaped our thinking toward the new hope and challenges in treatment of obesity and eating disorders.
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13
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Foradori CD, Whitlock BK, Daniel JA, Zimmerman AD, Jones MA, Read CC, Steele BP, Smith JT, Clarke IJ, Elsasser TH, Keisler DH, Sartin JL. Kisspeptin Stimulates Growth Hormone Release by Utilizing Neuropeptide Y Pathways and Is Dependent on the Presence of Ghrelin in the Ewe. Endocrinology 2017; 158:3526-3539. [PMID: 28977590 DOI: 10.1210/en.2017-00303] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/13/2017] [Indexed: 12/31/2022]
Abstract
Although kisspeptin is the primary stimulator of gonadotropin-releasing hormone secretion and therefore the hypothalamic-pituitary-gonadal axis, recent findings suggest kisspeptin can also regulate additional neuroendocrine processes including release of growth hormone (GH). Here we show that central delivery of kisspeptin causes a robust rise in plasma GH in fasted but not fed sheep. Kisspeptin-induced GH secretion was similar in animals fasted for 24 hours and those fasted for 72 hours, suggesting that the factors involved in kisspeptin-induced GH secretion are responsive to loss of food availability and not the result of severe negative energy balance. Pretreatment with the neuropeptide Y (NPY) Y1 receptor antagonist, BIBO 3304, blocked the effects of kisspeptin-induced GH release, implicating NPY as an intermediary. Kisspeptin treatment induced c-Fos in NPY and GH-releasing hormone (GHRH) cells of the arcuate nucleus. The same kisspeptin treatment resulted in a reduction in c-Fos in somatostatin (SS) cells in the periventricular nucleus. Finally, blockade of systemic ghrelin release or antagonism of the ghrelin receptor eliminated or reduced the ability of kisspeptin to induce GH release, suggesting the presence of ghrelin is required for kisspeptin-induced GH release in fasted animals. Our findings support the hypothesis that during short-term fasting, systemic ghrelin concentrations and NPY expression in the arcuate nucleus rise. This permits kisspeptin activation of NPY cells. In turn, NPY stimulates GHRH cells and inhibits SS cells, resulting in GH release. We propose a mechanism by which kisspeptin conveys reproductive and hormone status onto the somatotropic axis, resulting in alterations in GH release.
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Affiliation(s)
- Chad D Foradori
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
| | - Brian K Whitlock
- Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Tennessee 37996
| | - Jay A Daniel
- Department of Animal Science, Berry College, Mt. Berry, Georgia 30149
| | - Arthur D Zimmerman
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
| | - Melaney A Jones
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
| | - Casey C Read
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
| | - Barbara P Steele
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
| | - Jeremy T Smith
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, Crawley, Washington 6009, Australia
| | - Iain J Clarke
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Theodore H Elsasser
- Animal Genomics and Improvement Laboratory, US Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705
| | - Duane H Keisler
- Division of Animal Sciences, University of Missouri, Columbia, Missouri 65211
| | - James L Sartin
- Department of Anatomy, Physiology & Pharmacology, Auburn University, Auburn, Alabama 36849
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14
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Blanco AM, Bertucci JI, Valenciano AI, Delgado MJ, Unniappan S. Ghrelin suppresses cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) in the intestine, and attenuates the anorectic effects of CCK, PYY and GLP-1 in goldfish (Carassius auratus). Horm Behav 2017; 93:62-71. [PMID: 28506816 DOI: 10.1016/j.yhbeh.2017.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 04/27/2017] [Accepted: 05/12/2017] [Indexed: 02/06/2023]
Abstract
Ghrelin is an important gut-derived hormone with an appetite stimulatory role, while most of the intestinal hormones, including cholecystokinin (CCK), peptide YY (PYY) and glucagon-like peptide-1 (GLP-1), are appetite-inhibitors. Whether these important peptides with opposing roles on food intake interact to regulate energy balance in fish is currently unknown. The aim of this study was to characterize the putative crosstalk between ghrelin and CCK, PYY and GLP-1 in goldfish (Carassius auratus). We first determined the localization of CCK, PYY and GLP-1 in relation to ghrelin and its main receptor GHS-R1a (growth hormone secretagogue 1a) in the goldfish intestine by immunohistochemistry. Colocalization of ghrelin/GHS-R1a and CCK/PYY/GLP-1 was found primarily in the luminal border of the intestinal mucosa. In an intestinal explant culture, a significant decrease in prepro-cck, prepro-pyy and proglucagon transcript levels was observed after 60min of incubation with ghrelin, which was abolished by preincubation with the GHS-R1a ghrelin receptor antagonist [D-Lys3]-GHRP-6 (except for proglucagon). The protein expression of PYY and GLP-1 was also downregulated by ghrelin. Finally, intraperitoneal co-administration of CCK, PYY or GLP-1 with ghrelin results in no modification of food intake in goldfish. Overall, results of the present study show for the first time in fish that ghrelin exerts repressive effects on enteric anorexigens. It is likely that these interactions mediate the stimulatory effects of ghrelin on feeding and metabolism in fish.
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Affiliation(s)
- Ayelén Melisa Blanco
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain; Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada.
| | - Juan Ignacio Bertucci
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Avenida Intendente Marinos Km. 8,2, 7130 Chascomús, Buenos Aires, Argentina.
| | - Ana Isabel Valenciano
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain.
| | - María Jesús Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain.
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada.
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15
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Chen SR, Chen H, Zhou JJ, Pradhan G, Sun Y, Pan HL, Li DP. Ghrelin receptors mediate ghrelin-induced excitation of agouti-related protein/neuropeptide Y but not pro-opiomelanocortin neurons. J Neurochem 2017; 142:512-520. [DOI: 10.1111/jnc.14080] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/19/2017] [Accepted: 05/22/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Shao-Rui Chen
- Department of Anesthesiology and Perioperative Medicine; Center for Neuroscience and Pain Research; The University of Texas MD Anderson Cancer Center; Houston Texas USA
| | - Hong Chen
- Department of Anesthesiology and Perioperative Medicine; Center for Neuroscience and Pain Research; The University of Texas MD Anderson Cancer Center; Houston Texas USA
| | - Jing-Jing Zhou
- Department of Anesthesiology and Perioperative Medicine; Center for Neuroscience and Pain Research; The University of Texas MD Anderson Cancer Center; Houston Texas USA
| | - Geetali Pradhan
- Department of Pediatrics; USDA/ARS Children's Nutrition Research Center; Baylor College of Medicine; Houston Texas USA
| | - Yuxiang Sun
- Department of Pediatrics; USDA/ARS Children's Nutrition Research Center; Baylor College of Medicine; Houston Texas USA
- Department of Nutrition and Food Science (NFSC); Texas A&M University; College Station Texas USA
| | - Hui-Lin Pan
- Department of Anesthesiology and Perioperative Medicine; Center for Neuroscience and Pain Research; The University of Texas MD Anderson Cancer Center; Houston Texas USA
| | - De-Pei Li
- Department of Anesthesiology and Perioperative Medicine; Center for Neuroscience and Pain Research; The University of Texas MD Anderson Cancer Center; Houston Texas USA
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Hu X, Sheikhahmadi A, Li X, Wang Y, Jiao H, Lin H, Zhang B, Song Z. Effect of Zinc on Appetite Regulatory Peptides in the Hypothalamus of Salmonella-Challenged Broiler Chickens. Biol Trace Elem Res 2016; 172:228-233. [PMID: 26637494 DOI: 10.1007/s12011-015-0582-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/30/2015] [Indexed: 01/16/2023]
Abstract
The effects of dietary Zinc (Zn) supplementation on the gene expression of appetite regulatory peptides were investigated in Salmonella-infected broiler chickens. Broiler chickens (Arbor Acres, 1 day old) were allocated randomly into 24 pens of 10 birds. The chickens from 12 pens were fed with basal diet and the other with basal diet supplemented with Zn (ZnSO4·H2O, 120 mg/kg). At 5 days of age, the chickens were divided into 4 treatments with 6 pens: basal diet; basal diet and Salmonella challenge; Zn-supplemented diet; Zn-supplemented diet and Salmonella challenge. At 42 days of age, the hypothalamus from 6 chickens per treatment (1 chicken per pen) was individually collected for gene expression determination. Results showed that dietary supplementation of Zn reduced the gene expression of hypothalamic ghrelin and tumor necrosis factor alpha (TNF-α) (P < 0.05). Salmonella infection upregulated the messenger RNA (mRNA) levels of hypothalamic neuropeptide Y (NPY) and TNF-α. Zn supplementation and Salmonella inoculation were significantly correlated with the mRNA levels of toll-like receptor 2-1 (P < 0.05). However, neither dietary Zn supplementation nor Salmonella inoculation had significant effect on hypothalamic agouti-related protein, cocaine- and amphetamine-regulated transcript, and pro-opiomelanocortin. This study shows that dietary Zn supplementation promoted orexigenic appetite regulatory peptides and reduced the expression of the inflammatory cytokine TNF-α in the hypothalamus of Salmonella-challenged broilers.
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Affiliation(s)
- Xiyi Hu
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Ardashir Sheikhahmadi
- Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, 66177-15175, Iran
| | - Xianlei Li
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Yufeng Wang
- Division Livestock-Nutrition-Quality, Department of Biosystems, KU Leuven, Kasteelpark Arenberg 30, 3001, Leuven, Belgium
| | - Hongchao Jiao
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Hai Lin
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong, 271018, China
| | - Bingkun Zhang
- College of Animal Science, China Agricultural University, Beijing, 100094, China
| | - Zhigang Song
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong, 271018, China.
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17
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Reactive oxygen species mediate insulin signal transduction in mouse hypothalamus. Neurosci Lett 2016; 619:1-7. [PMID: 26968348 DOI: 10.1016/j.neulet.2016.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 01/26/2023]
Abstract
In the hypothalamus, several reports have implied that ROS mediate physiological effects of insulin. In this study, we investigated the mechanisms of insulin-induced ROS production and the effect of ROS on insulin signal transduction in mouse hypothalamic organotypic cultures. Insulin increased intracellular ROS, which were suppressed by NADPH oxidase inhibitor. H2O2 increased phospho-insulin receptor β (p-IRβ) and phospho-Akt (p-Akt) levels. Insulin-induced increases in p-IRβ and p-Akt levels were attenuated by ROS scavenger or NADPH oxidase inhibitor. Our data suggest that insulin-induced phosphorylation of IRβ and Akt is mediated via ROS which are predominantly produced by NADPH oxidase in mouse hypothalamus.
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Yasrebi A, Hsieh A, Mamounis KJ, Krumm EA, Yang JA, Magby J, Hu P, Roepke TA. Differential gene regulation of GHSR signaling pathway in the arcuate nucleus and NPY neurons by fasting, diet-induced obesity, and 17β-estradiol. Mol Cell Endocrinol 2016; 422:42-56. [PMID: 26577678 PMCID: PMC4742417 DOI: 10.1016/j.mce.2015.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 12/20/2022]
Abstract
Ghrelin's receptor, growth hormone secretagogue receptor (GHSR), is highly expressed in the arcuate nucleus (ARC) and in neuropeptide Y (NPY) neurons. Fasting, diet-induced obesity (DIO), and 17β-estradiol (E2) influence ARC Ghsr expression. It is unknown if these effects occur in NPY neurons. Therefore, we examined the expression of Npy, Agrp, and GHSR signaling pathway genes after fasting, DIO, and E2 replacement in ARC and pools of NPY neurons. In males, fasting increased ARC Ghsr and NPY Foxo1 but decreased NPY Ucp2. In males, DIO decreased ARC and NPY Ghsr and Cpt1c. In fed females, E2 increased Agrp, Ghsr, Cpt1c, and Foxo1 in ARC. In NPY pools, E2 decreased Foxo1 in fed females but increased Foxo1 in fasted females. DIO in females suppressed Agrp and augmented Cpt1c in NPY neurons. In summary, genes involved in GHSR signaling are differentially regulated between the ARC and NPY neurons in a sex-dependent manner.
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Affiliation(s)
- Ali Yasrebi
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Anna Hsieh
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Kyle J Mamounis
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Nutritional Sciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Elizabeth A Krumm
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Jennifer A Yang
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Jason Magby
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Pu Hu
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Troy A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Nutritional Sciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Graduate Program in Endocrinology and Animal Biosciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; New Jersey Institute for Food, Nutrition, and Health, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
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Gao H, Sisley S, Yallampalli C. Blunted hypothalamic ghrelin signaling reduces diet intake in rats fed a low-protein diet in late pregnancy. Physiol Rep 2015; 3:3/12/e12629. [PMID: 26660550 PMCID: PMC4760445 DOI: 10.14814/phy2.12629] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Diet intake in pregnant rats fed a low‐protein (LP) diet was significantly reduced during late pregnancy despite elevated plasma levels of ghrelin. In this study, we hypothesized that ghrelin signaling in the hypothalamus is blunted under a low‐protein diet condition and therefore, it does not stimulate diet intake during late pregnancy. Female Sprague–Dawley rats were fed a normal (CT) or LP diet from Day 1 of pregnancy. On Day 21, 0.5 μg ghrelin was given into the third ventricle (ICV). Diet and water intake at 30, 60, and 120 min after ICV injection was measured. Hypothalami were dissected and analyzed for expression of genes related to appetite regulation (Npy, Agrp, Pomc and Cart) and phosphorylation of AMPK and ACC proteins (downstream proteins of ghrelin receptor activation). Results include: In response to ICV injection of ghrelin, (1) diet intake was significantly lower in LP compared to CT rats; (2) water intake was not affected in LP rats; (3) expression of Npy and Agrp, but not Pomc and Cart, were higher in the hypothalamus of LP compared to CT rats; (4) the abundance of phosphorylated AMPK and the ratio of phosphorylated to total AMPK, but not the abundance of total AMPK, were lower in LP compared to CT rats; (5) the abundance of phosphorylated ACC, but not total ACC, was lower in LP rats. These findings suggest that blunted ghrelin signaling in the hypothalamus of pregnant rats fed a LP diet leads to reduced diet intake and exacerbates gestational protein insufficiency.
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Affiliation(s)
- Haijun Gao
- Department of Obstetrics & Gynecology, Baylor College of Medicine, Houston, Texas
| | - Stephanie Sisley
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Chandra Yallampalli
- Department of Obstetrics & Gynecology, Baylor College of Medicine, Houston, Texas
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20
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Why is obesity such a problem in the 21st century? The intersection of palatable food, cues and reward pathways, stress, and cognition. Neurosci Biobehav Rev 2015; 58:36-45. [DOI: 10.1016/j.neubiorev.2014.12.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 11/15/2014] [Accepted: 12/02/2014] [Indexed: 01/10/2023]
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21
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Gali Ramamoorthy T, Begum G, Harno E, White A. Developmental programming of hypothalamic neuronal circuits: impact on energy balance control. Front Neurosci 2015; 9:126. [PMID: 25954145 PMCID: PMC4404811 DOI: 10.3389/fnins.2015.00126] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/26/2015] [Indexed: 01/08/2023] Open
Abstract
The prevalence of obesity in adults and children has increased globally at an alarming rate. Mounting evidence from both epidemiological studies and animal models indicates that adult obesity and associated metabolic disorders can be programmed by intrauterine and early postnatal environment- a phenomenon known as "fetal programming of adult disease." Data from nutritional intervention studies in animals including maternal under- and over-nutrition support the developmental origins of obesity and metabolic syndrome. The hypothalamic neuronal circuits located in the arcuate nucleus controlling appetite and energy expenditure are set early in life and are perturbed by maternal nutritional insults. In this review, we focus on the effects of maternal nutrition in programming permanent changes in these hypothalamic circuits, with experimental evidence from animal models of maternal under- and over-nutrition. We discuss the epigenetic modifications which regulate hypothalamic gene expression as potential molecular mechanisms linking maternal diet during pregnancy to the offspring's risk of obesity at a later age. Understanding these mechanisms in key metabolic genes may provide insights into the development of preventative intervention strategies.
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Affiliation(s)
| | - Ghazala Begum
- School of Clinical and Experimental Medicine, University of Birmingham Birmingham, UK
| | - Erika Harno
- Faculty of Life Sciences, University of Manchester Manchester, UK
| | - Anne White
- Faculty of Life Sciences, University of Manchester Manchester, UK ; Faculty of Medical and Human Sciences, Centre for Endocrinology and Diabetes, University of Manchester Manchester, UK
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22
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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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Aréchiga-Ceballos F, Alvarez-Salas E, Matamoros-Trejo G, Amaya MI, García-Luna C, de Gortari P. Pro-TRH and pro-CRF expression in paraventricular nucleus of small litter-reared fasted adult rats. J Endocrinol 2014; 221:77-88. [PMID: 24464021 DOI: 10.1530/joe-13-0458] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neuroendocrine axes adapt to nutrient availability. During fasting, the function of the hypothalamus-pituitary-thyroid axis (HPT) is reduced, whereas that of the hypothalamus-pituitary-adrenal axis (HPA) is increased. Overfeeding-induced hyperleptinemia during lactation may alter the regulatory set point of neuroendocrine axes and their adaptability to fasting in adulthood. Hyperleptinemia is developed in rodents by litter size reduction during lactation; adult rats from small litters become overweight, but their paraventricular nucleus (PVN) TRH synthesis is unchanged. It is unclear whether peptide expression still responds to nutrient availability. PVN corticotropin-releasing factor (CRF) expression has not been evaluated in this model. We analyzed adaptability of HPT and HPA axes to fasting-induced low leptin levels of reduced-litter adult rats. Offspring litters were reduced to 2-3/dam (early-overfed) or maintained at 8/dam (controls, C). At 10 weeks old, a subset of animals from each group was fasted for 48 h and leptin, corticosterone, and thyroid hormones serum levels were analyzed. In brain, expressions of leptin receptor, NPY and SOCS3, were evaluated in arcuate nucleus, and those of proTRH and proCRF in PVN by real-time PCR. ProTRH expression in anterior and medial PVN subcompartments was assayed by in situ hybridization. Early-overfed adults developed hyperphagia and excessive weight, together with decreased proTRH expression in anterior PVN, supporting the anorexigenic effects of TRH. Early-overfed rats presented low PVN proTRH synthesis, whereas fasting did not induce a further reduction. Fasting-induced stress was unable to increase corticosterone levels, contributing to reduced body weight loss in early-overfed rats. We concluded that early overfeeding impaired the adaptability of HPT and HPA axes to excess weight and fasting in adults.
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Affiliation(s)
- F Aréchiga-Ceballos
- Neurofisiología Molecular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz (INPRFM), Calzada México-Xochimilco 101, Col. San Lorenzo Huipulco, C.P. 14370, México, Distrito Federal, México Escuela de Dietética y Nutrición, ISSSTE, Callejón Vía San Fernando #12, México, Distrito Federal, México
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Adachi K, Goto M, Onoue T, Tsunekawa T, Shibata M, Hagimoto S, Ito Y, Banno R, Suga H, Sugimura Y, Oiso Y, Arima H. Mitogen-activated protein kinase phosphatase 1 negatively regulates MAPK signaling in mouse hypothalamus. Neurosci Lett 2014; 569:49-54. [PMID: 24686178 DOI: 10.1016/j.neulet.2014.03.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 03/18/2014] [Accepted: 03/20/2014] [Indexed: 01/09/2023]
Abstract
Mitogen-activated protein kinase phosphatase 1 (MKP-1) is shown to negatively regulate MAPK signaling in various peripheral tissues as well as the central nervous system such as cortex, striatum and hippocampus. In this study, we examined whether MKP-1 regulates MAPK signaling in the mouse hypothalamus. Intraperitoneal injection of TNFα significantly increased MKP-1 mRNA expression in paraventricular and arcuate nuclei in the hypothalamus. TNFα treatment induced increases in MKP-1 expression at both mRNA and protein levels, accompanied by the inactivation of MAPK signaling in mouse hypothalamic explants. Inhibition of MKP-1 by its inhibitor or siRNA increased MAPK activity in the explants. Our data indicate that MKP-1 negatively regulates MAPK signaling in the mouse hypothalamus.
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Affiliation(s)
- Koichi Adachi
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Motomitsu Goto
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan.
| | - Takeshi Onoue
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Taku Tsunekawa
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Miyuki Shibata
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Shigeru Hagimoto
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Yoshihiro Ito
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Ryoichi Banno
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Hidetaka Suga
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Yoshihisa Sugimura
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Yutaka Oiso
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan
| | - Hiroshi Arima
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550, Japan.
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Hagimoto S, Arima H, Adachi K, Ito Y, Suga H, Sugimura Y, Goto M, Banno R, Oiso Y. Expression of neuropeptide Y and agouti-related protein mRNA stimulated by glucocorticoids is attenuated via NF-κB p65 under ER stress in mouse hypothalamic cultures. Neurosci Lett 2013; 553:165-9. [DOI: 10.1016/j.neulet.2013.08.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 08/07/2013] [Accepted: 08/20/2013] [Indexed: 11/27/2022]
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Ribeiro G, Santos O. Recompensa alimentar: mecanismos envolvidos e implicações para a obesidade. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.rpedm.2013.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Upton KR, Riley LG. Acute stress inhibits food intake and alters ghrelin signaling in the brain of tilapia (Oreochromis mossambicus). Domest Anim Endocrinol 2013; 44:157-64. [PMID: 23291012 DOI: 10.1016/j.domaniend.2012.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/04/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
This study investigated the effect of an acute stress on food intake and on the expression of neuropeptide Y (NPY), corticotropin-releasing hormone (CRH), and ghrelin and its receptors, growth hormone secretagogue receptors (GHSRs) in the tilapia (Oreochromis mossambicus). Food intake was significantly (P < 0.01) reduced in fish after a 30-min crowding and handling stress. In a second group of animals exposed to the same 30-min stressor, tissue samples were collected immediately after the stressor to determine changes in the neuroendocrine regulators of food intake. Although CRH and NPY are considered the major mediators of appetite during stress, both mRNA levels were unaltered in the telencephalon/pre-optic area and in the hypothalamic/optic tectum. Interestingly, there was an elevation in the ghrelin transcript (P < 0.05) in the telencephalon/pre-optic area and elevation of its functional receptor (GHSR1a-LR) (P < 0.001) in the hypothalamic/optic tectum. Elevation of GHSR-LR heteronuclear RNA (P < 0.01) in the telencephalon/pre-optic area and suppression in the hypothalamic/optic tectum (P < 0.001) suggest rapid control of the ghrelin regulatory system in response to acute stress. These results suggest that ghrelin signaling is altered during acute stress. It is not clear if these changes result in altered feeding behavior because no changes in CRH or NPY mRNA expression were observed or if ghrelin is playing a role in regulating overall metabolic changes after acute stress.
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Affiliation(s)
- K R Upton
- Department of Biology, California State University at Fresno, Fresno, CA 93740, USA
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Liu T, Wang Q, Berglund ED, Tong Q. Action of Neurotransmitter: A Key to Unlock the AgRP Neuron Feeding Circuit. Front Neurosci 2013; 6:200. [PMID: 23346045 PMCID: PMC3549528 DOI: 10.3389/fnins.2012.00200] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 12/31/2012] [Indexed: 01/08/2023] Open
Abstract
The current obesity epidemic and lack of efficient therapeutics demand a clear understanding of the mechanism underlying body weight regulation. Despite intensive research focus on obesity pathogenesis, an effective therapeutic strategy to treat and cure obesity is still lacking. Exciting studies in last decades have established the importance of hypothalamic agouti-related protein-expressing neurons (AgRP neurons) in the regulation of body weight homeostasis. AgRP neurons are both required and sufficient for feeding regulation. The activity of AgRP neurons is intricately regulated by nutritional hormones as well as synaptic inputs from upstream neurons. Changes in AgRP neuron activity lead to alterations in the release of mediators, including neuropeptides Neuropeptide Y (NPY) and AgRP, and fast-acting neurotransmitter GABA. Recent studies based on mouse genetics, novel optogenetics, and designer receptor exclusively activated by designer drugs have identified a critical role for GABA release from AgRP neurons in the parabrachial nucleus and paraventricular hypothalamus in feeding control. This review will summarize recent findings about AgRP neuron-mediated control of feeding circuits with a focus on the role of neurotransmitters. Given the limited knowledge on feeding regulation, understanding the action of neurotransmitters may be a key to unlock neurocircuitry that governs feeding.
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Affiliation(s)
- Tiemin Liu
- Division of Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas Dallas, TX, USA
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Lesion of area postrema attenuated hyperphagic responses to glucoprivation, but not transcriptional activation of the neuropeptide Y gene in rats. Neuroreport 2012; 23:673-5. [DOI: 10.1097/wnr.0b013e3283556676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Kalyani RR, Varadhan R, Weiss CO, Fried LP, Cappola AR. Frailty status and altered dynamics of circulating energy metabolism hormones after oral glucose in older women. J Nutr Health Aging 2012; 16:679-86. [PMID: 23076509 DOI: 10.1007/s12603-012-0066-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Frailty status is associated with altered glucose-insulin dynamics. Here, we sought to investigate whether alteration in the dynamics of other circulating energy metabolism hormones after oral glucose is associated with frailty status. DESIGN Substudy of older women in a prospective cohort. SETTING Baltimore, Maryland. PARTICIPANTS Seventy-three community-dwelling women aged 84-95 years without a diagnosis of diabetes who were enrolled in the Women's Health and Aging Study II. MEASUREMENTS We examined stimulus-response dynamics of free fatty acids (FFA), gut- (ghrelin,GLP-1) and adipocyte-derived hormones (leptin, adiponectin, resistin), growth hormone (GH), insulin-like growth factor 1 (IGF-1), and interleukin-6 (IL-6) at 0, 30, 60, 120, and 180-minutes after a 75-g glucose challenge according to frailty status (non-frail, pre-frail, or frail). RESULTS On average, frail women had higher fasting levels of glucose-raising hormones (FFA, resistin, GH, and IL-6) and lower fasting levels of glucose-lowering hormones (ghrelin, adiponectin, GLP-1 and IGF-1) versus non-frail women but these results were not statistically significant. Frail women also had higher fasting levels of leptin with relative adiposity compared to their counterparts, suggestive of leptin-resistance. Integrated area under the curve (AUC) values for each hormone followed similar trends by frailty status. After age and BMI adjustment, frail versus non-frail women were more likely to be in the lowest tertile of fasting ghrelin levels and 120-min ghrelin levels (both p<0.05) in logistic regression analyses. No large differences were found for other hormones in adjusted models. CONCLUSIONS Our findings suggest dysregulation of the orexigenic hormone ghrelin in the frailty syndrome. Further studies are needed to explore the role of ghrelin dysregulation in the clinical manifestation of frailty.
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Affiliation(s)
- R R Kalyani
- Division of Endocrinology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
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Effect of heat exposure on gene expression of feed intake regulatory peptides in laying hens. J Biomed Biotechnol 2012; 2012:484869. [PMID: 22619495 PMCID: PMC3352661 DOI: 10.1155/2012/484869] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 01/27/2012] [Accepted: 02/16/2012] [Indexed: 11/17/2022] Open
Abstract
The aim of this paper was to investigate the effect of heat stress on the regulation of appetite-associated genes in laying hens. Forty eight laying hens were randomly divided into two circumstances: high (31 ± 1.5°C; relative humidity, 82.0 ± 2.2%) or normal (20 ± 2°C, control; relative humidity, 60.1 ± 4.5%) ambient environment. Heat stress decreased body weight gain (P < 0.01), feed intake (P < 0.01), laying rate (P < 0.05), average egg mass (P < 0.01), egg production (P < 0.01), shell thickness (P < 0.01), and feed efficiency (P < 0.05). High ambient temperature decreased plasma uric acid (P < 0.05). Heat stress significantly increased mRNA levels of ghrelin and cocaine- and amphetamine-regulated transcript (P < 0.05) and decreased mRNA levels of cholecystokinin (P < 0.05) in the hypothalamus. Heat stress significantly increased (P < 0.05) mRNA levels of ghrelin in the glandular stomach and jejunum but significantly decreased (P < 0.05) mRNA levels of cholecystokinin in the duodenum and jejunum. In conclusion, heat stress plays a unique role in some special neuropeptides (e.g., ghrelin, cocaine- and amphetamine-regulated transcript, and cholecystokinin), which might participate in the regulation of feed intake in laying hens under high ambient temperature.
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Maniam J, Morris MJ. The link between stress and feeding behaviour. Neuropharmacology 2012; 63:97-110. [PMID: 22710442 DOI: 10.1016/j.neuropharm.2012.04.017] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 04/11/2012] [Accepted: 04/20/2012] [Indexed: 02/06/2023]
Abstract
Exposure to stress is inevitable, and it may occur, to varying degrees, at different phases throughout the lifespan. The impact of stress experienced in later life has been well documented as many populations in modern society experience increasing socio-economic demands. The effects of stress early in life are less well known, partly as the impact of an early exposure may be difficult to quantify, however emerging evidence shows it can impact later in life. One of the major impacts of stress besides changes in psychosocial behaviour is altered feeding responses. The system that regulates stress responses, the hypothalamo-pituitary-adrenal axis, also regulates feeding responses because the neural circuits that regulate food intake converge on the paraventricular nucleus, which contains corticotrophin releasing hormone (CRH), and urocortin containing neurons. In other words the systems that control food intake and stress responses share the same anatomy and thus each system can influence each other in eliciting a response. Stress is known to alter feeding responses in a bidirectional pattern, with both increases and decreases in intake observed. Stress-induced bidirectional feeding responses underline the complex mechanisms and multiple contributing factors, including the levels of glucocorticoids (dependent on the severity of a stressor), the interaction between glucocorticoids and feeding related neuropeptides such as neuropeptide Y (NPY), alpha-melanocyte stimulating hormone (α-MSH), agouti-related protein (AgRP), melanocortins and their receptors, CRH, urocortin and peripheral signals (leptin, insulin and ghrelin). This review discusses the neuropeptides that regulate feeding behaviour and how their function can be altered through cross-talk with hormones and neuropeptides that also regulate the hypothalamo-pituitary-adrenal axis. In addition, long-term stress induced alterations in feeding behaviour, and changes in gene expression of neuropeptides regulating stress and food intake through epigenetic modifications will be discussed. This article is part of a Special Issue entitled 'SI: Central Control of Food Intake'.
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Affiliation(s)
- Jayanthi Maniam
- Pharmacology, School of Medical Sciences, University of New South Wales, Sydney NSW 2052, Australia
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33
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Electrophysiological analysis of circuits controlling energy homeostasis. Mol Neurobiol 2012; 45:258-78. [PMID: 22331510 DOI: 10.1007/s12035-012-8241-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/26/2012] [Indexed: 10/28/2022]
Abstract
Since the discovery of leptin and the central melanocortin circuit, electrophysiological studies have played a major role in elucidating mechanisms underlying energy homeostasis. This review highlights the contribution of findings made by electrophysiological measurements to the current understanding of hypothalamic neuronal networks involved in energy homeostasis with a specific focus on the arcuate-paraventricular nucleus circuit.
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Ito Y, Banno R, Hagimoto S, Ozawa Y, Arima H, Oiso Y. TNFα increases hypothalamic PTP1B activity via the NFκB pathway in rat hypothalamic organotypic cultures. ACTA ACUST UNITED AC 2012; 174:58-64. [DOI: 10.1016/j.regpep.2011.11.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 11/03/2011] [Accepted: 11/29/2011] [Indexed: 01/03/2023]
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Abstract
Ghrelin is a pleiotropic hormone that was originally described as promoting feeding and stimulating growth hormone release in adults. A growing body of evidence suggests that ghrelin may also exert developmental and organizational effects during perinatal life. The perinatal actions of ghrelin include the regulation of early developmental events such as blastocyst development and perinatal growth. Moreover, alterations in perinatal ghrelin levels result in structural differences in various peripheral organs, such as the pancreas and gastrointestinal tract. Recent data have also suggested that ghrelin acts on appetite-related brain centers in early life. Together, these observations indicate that exposure to factors that alter how ghrelin impacts development may induce lasting effects on physiological regulation.
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Affiliation(s)
- Sophie M. Steculorum
- The Saban Research Institute, Neuroscience Program, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA 90027, USA
- Inserm, Jean-Pierre Aubert Research Center, U837, Neurobese Lab, University Lille 2, Lille, 59045, France
| | - Sebastien G. Bouret
- The Saban Research Institute, Neuroscience Program, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA 90027, USA
- Inserm, Jean-Pierre Aubert Research Center, U837, Neurobese Lab, University Lille 2, Lille, 59045, France
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Shan X, Yeo GSH. Central leptin and ghrelin signalling: comparing and contrasting their mechanisms of action in the brain. Rev Endocr Metab Disord 2011; 12:197-209. [PMID: 21331644 DOI: 10.1007/s11154-011-9171-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the past two decades, two major discoveries have greatly contributed to our current knowledge on the central control of food intake and body-weight; the discovery of the anorexigenic adipocyte derived hormone leptin in 1994 and the orexigenic gut derived hormone ghrelin in 1999. Both hormones act as crucial signals to indicate nutritional status as well as to modulate feeding behaviour through a variety of distinct pathways. They target overlapping CNS regions in order to mediate their obvious opposing effects on energy balance. Here we depict the integral picture of leptin and ghrelin on central regulation of food intake by reviewing their actions across the CNS, in regions of the hypothalamus, brainstem, mesolimbic reward pathway and other higher brain areas.
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Affiliation(s)
- Xiaoye Shan
- University of Cambridge Metabolic Research Labs, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
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37
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Ozawa Y, Arima H, Watanabe M, Shimizu H, Ito Y, Banno R, Sugimura Y, Ozaki N, Nagasaki H, Oiso Y. Repeated glucoprivation delayed hyperphagic responses while activating neuropeptide Y neurons in rats. Peptides 2011; 32:763-9. [PMID: 21184790 DOI: 10.1016/j.peptides.2010.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 12/08/2010] [Accepted: 12/14/2010] [Indexed: 11/23/2022]
Abstract
It is well known that glucoprivation induces the release of counterregulatory hormones such as glucagon, and that the response is attenuated when the stimuli are repeated. Glucoprivation also activates orexigenic neurons and induces hyperphagic responses, although it remains unclear whether these responses are attenuated in repeated glucoprivation. In this study, we examined time course changes in feeding as well as activities of orexigenic neuropeptide Y (NPY) neurons in repeated glucoprivation in rats. Either 2-deoxy-d-glucose (2DG), which blocks glucose utilization, or isotonic saline (control) was injected subcutaneously to rats for 14 days, and food consumption for 1 and 2h after injection was monitored throughout the experiment. While 2DG injection induced robust feeding responses during the first 1h after injection, the response was gradually attenuated and the food consumption was significantly less on days 12-14 compared to that on day 1. On the other hand, food consumption during 2h after 2DG injection was not changed significantly for 14 days. The transcriptional activities of NPY neurons in the arcuate nucleus and C1/A1 region of the hindbrain, measured by intronic in situ hybridization, were significantly enhanced after repeated 2DG injection for 14 days, while the feeding responses to intracerebroventricular injection of NPY were significantly less in the 2DG-repeated group compared to the saline-repeated group. It is thus demonstrated that repeated glucoprivation delayed hyperphagic responses while activating NPY neurons in rats. Our data also suggest that decreased feeding responses to NPY might be at least partially responsible for the delayed response.
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Affiliation(s)
- Yoshiharu Ozawa
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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SEDLÁČKOVÁ D, KOPEČKOVÁ J, PAPEŽOVÁ H, VYBÍRAL S, KVASNIČKOVÁ H, HILL M, NEDVÍDKOVÁ J. Changes of Plasma Obestatin, Ghrelin and NPY in Anorexia and Bulimia Nervosa Patients Before and After a High-Carbohydrate Breakfast. Physiol Res 2011; 60:165-73. [DOI: 10.33549/physiolres.931952] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Peptides ghrelin, obestatin and neuropeptide Y (NPY) play an important role in regulation of energy homeostasis, the imbalance of which is associated with eating disorders anorexia (AN) and bulimia nervosa (BN). The changes in ghrelin, obestatin and NPY plasma levels were investigated in AN and BN patients after administration of a high-carbohydrate breakfast (1604 kJ). Eight AN women (aged 25.4±1.9; BMI: 15.8±0.5), thirteen BN women (aged 22.0±1.05; BMI: 20.1±0.41) and eleven healthy women (aged 25.1±1.16; BMI: 20.9±0.40) were recruited for the study. We demonstrated increased fasting ghrelin in AN, but not in BN patients, while fasting obestatin and NPY were increased in both AN and BN patients compared to the controls. Administration of high-carbohydrate breakfast induced a similar relative decrease in ghrelin and obestatin plasma levels in all groups, while NPY remained increased in postprandial period in both patient groups. Ghrelin/obestatin ratio was lower in AN and BN compared to the controls. In conclusions, increased plasma levels of fasting NPY and its unchanged levels after breakfast indicate that NPY is an important marker of eating disorders AN and BN. Different fasting ghrelin and obestatin levels in AN and BN could demonstrate their diverse functions in appetite and eating suppression.
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Affiliation(s)
| | | | | | | | | | | | - J. NEDVÍDKOVÁ
- Institute of Endocrinology, Laboratory of Clinical and Experimental Neuroendocrinology, Prague, Czech Republic
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Effect of feeding status on adjuvant arthritis severity, cachexia, and insulin sensitivity in male Lewis rats. Mediators Inflamm 2010; 2010. [PMID: 20953376 PMCID: PMC2952917 DOI: 10.1155/2010/398026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 09/09/2010] [Indexed: 12/23/2022] Open
Abstract
We studied the effect of food restriction, overfeeding, and normofeeding on cachexia, inflammatory and metabolic parameters, and insulin sensitivity in chronic adjuvant arthritis (AA) in rats. Food restriction during AA increased circulating ghrelin, corticosterone, decreased leptin, and ameliorated arthrogram score and systemic inflammation compared to normofeeding. Overfeeding worsened arthrogram score and systemic inflammation, and led to lipid accumulation in the liver, but not to alterations of adipokine and ghrelin plasma levels relative to normofeeding. Independently of feeding status, AA induced cachexia, in which modulation of mRNA expressions for appetite-regulating neuropeptides (NPY, AgRP, POMC, CART) in the arcuate nucleus (ARC) does not play a primary role. The overexpression of IL-1β mRNA in the ARC suggests its role in the mechanisms of impaired energy balance during AA under all feeding conditions. Normal HOMA index in all arthritic groups does not indicate the development of insulin resistance by feeding interventions in these rats.
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Burns B, Schmidt K, Williams SR, Kim S, Girirajan S, Elsea SH. Rai1 haploinsufficiency causes reduced Bdnf expression resulting in hyperphagia, obesity and altered fat distribution in mice and humans with no evidence of metabolic syndrome. Hum Mol Genet 2010; 19:4026-42. [PMID: 20663924 DOI: 10.1093/hmg/ddq317] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Smith-Magenis syndrome (SMS) is a genetic disorder caused by haploinsufficiency of the retinoic acid induced 1 (RAI1) gene. In addition to intellectual disabilities, behavioral abnormalities and sleep disturbances, a majority of children with SMS also have significant early-onset obesity. To study the role of RAI1 in obesity, we investigated the growth and obesity phenotype in a mouse model haploinsufficient for Rai1. Data show that Rai1(+/-) mice are hyperphagic, have an impaired satiety response and have altered abdominal and subcutaneous fat distribution, with Rai1(+/-) female mice having a higher proportion of abdominal fat when compared with wild-type female mice. Expression analyses revealed that Bdnf (brain-derived neurotrophic factor), a gene previously associated with hyperphagia and obesity, is downregulated in the Rai1(+/-) mouse hypothalamus, and reporter studies show that RAI1 directly regulates the expression of BDNF. Even though the Rai1(+/-) mice are significantly obese, serum analyses do not reveal any evidence of metabolic syndrome. Supporting these findings, a caregiver survey revealed that even though a high incidence of abdominal obesity is observed in females with SMS, they did not exhibit a higher incidence of indicators of metabolic syndrome above the general population. We conclude that Rai1 haploinsufficiency represents a single-gene model of obesity with hyperphagia, abnormal fat distribution and altered hypothalamic gene expression associated with satiety, food intake, behavior and obesity. Linking RAI1 and BDNF provides a more thorough understanding of the role of Rai1 in growth and obesity and insight into the complex pathogenicity of obesity, behavior and sex-specific differences in adiposity.
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Affiliation(s)
- Brooke Burns
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA
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Abstract
An increase in proinflammatory cytokines, a decrease in endothelial nitric oxide and adiponectin levels and an alteration in hypothalamic peptides and gastrointestinal hormones that regulate satiety, hunger and food intake all occur in metabolic syndrome. Consumption of a diet that is energy dense and rich in saturated and trans-fats by pregnant women and lactating mothers, in childhood and adult life may trigger changes in the hypothalamic and gut peptides and hormones. Such changes modulate immune response and inflammation and lead to alterations in the hypothalamic 'bodyweight/appetite/satiety set point' and result in the initiation and development of the metabolic syndrome. Roux-en-gastric bypass induces weight loss, decreases the levels of cytokines and restores hypothalamic neuropeptides and gut hormones and the hypothalamic bodyweight/appetite/satiety set point to normal. Thus, metabolic syndrome is a low-grade systemic inflammatory condition with its origins in the perinatal period and childhood.
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Affiliation(s)
- Undurti N Das
- a UND Life Sciences, OH, USA and Jawaharlal Nehru Technological University, Kakinada-5330 003, Andhra Pradesh, India.
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Ferrini F, Salio C, Lossi L, Merighi A. Ghrelin in central neurons. Curr Neuropharmacol 2010; 7:37-49. [PMID: 19721816 PMCID: PMC2724662 DOI: 10.2174/157015909787602779] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 08/15/2008] [Accepted: 09/01/2008] [Indexed: 12/20/2022] Open
Abstract
Ghrelin, an orexigenic peptide synthesized by endocrine cells of the gastric mucosa, is released in the bloodstream in response to a negative energetic status. Since discovery, the hypothalamus was identified as the main source of ghrelin in the CNS, and effects of the peptide have been mainly observed in this area of the brain. In recent years, an increasing number of studies have reported ghrelin synthesis and effects in specific populations of neurons also outside the hypothalamus. Thus, ghrelin activity has been described in midbrain, hindbrain, hippocampus, and spinal cord. The spectrum of functions and biological effects produced by the peptide on central neurons is remarkably wide and complex. It ranges from modulation of membrane excitability, to control of neurotransmitter release, neuronal gene expression, and neuronal survival and proliferation. There is not at present a general consensus concerning the source of ghrelin acting on central neurons. Whereas it is widely accepted that the hypothalamus represents the most important endogenous source of the hormone in CNS, the existence of extra-hypothalamic ghrelin-synthesizing neurons is still controversial. In addition, circulating ghrelin can theoretically be another natural ligand for central ghrelin receptors. This paper gives an overview on the distribution of ghrelin and its receptor across the CNS and critically analyses the data available so far as regarding the effects of ghrelin on central neurotransmission.
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Affiliation(s)
- F Ferrini
- Dipartimento di Morfofisiologia Veterinaria, Università di Torino, Via Leonardo da Vinci 44, 10095, Grugliasco, Italy
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Chen CY, Asakawa A, Fujimiya M, Lee SD, Inui A. Ghrelin gene products and the regulation of food intake and gut motility. Pharmacol Rev 2010; 61:430-81. [PMID: 20038570 DOI: 10.1124/pr.109.001958] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A breakthrough using "reverse pharmacology" identified and characterized acyl ghrelin from the stomach as the endogenous cognate ligand for the growth hormone (GH) secretagogue receptor (GHS-R) 1a. The unique post-translational modification of O-n-octanoylation at serine 3 is the first in peptide discovery history and is essential for GH-releasing ability. Des-acyl ghrelin, lacking O-n-octanoylation at serine 3, is also produced in the stomach and remains the major molecular form secreted into the circulation. The third ghrelin gene product, obestatin, a novel 23-amino acid peptide identified from rat stomach, was found by comparative genomic analysis. Three ghrelin gene products actively participate in modulating appetite, adipogenesis, gut motility, glucose metabolism, cell proliferation, immune, sleep, memory, anxiety, cognition, and stress. Knockdown or knockout of acyl ghrelin and/or GHS-R1a, and overexpression of des-acyl ghrelin show benefits in the therapy of obesity and metabolic syndrome. By contrast, agonism of acyl ghrelin and/or GHS-R1a could combat human anorexia-cachexia, including anorexia nervosa, chronic heart failure, chronic obstructive pulmonary disease, liver cirrhosis, chronic kidney disease, burn, and postsurgery recovery, as well as restore gut dysmotility, such as diabetic or neurogenic gastroparesis, and postoperative ileus. The ghrelin acyl-modifying enzyme, ghrelin O-Acyltransferase (GOAT), which attaches octanoate to serine-3 of ghrelin, has been identified and characterized also from the stomach. To date, ghrelin is the only protein to be octanylated, and inhibition of GOAT may have effects only on the stomach and is unlikely to affect the synthesis of other proteins. GOAT may provide a critical molecular target in developing novel therapeutics for obesity and type 2 diabetes.
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Affiliation(s)
- Chih-Yen Chen
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Japan
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Shimizu H, Arima H, Ozawa Y, Watanabe M, Banno R, Sugimura Y, Ozaki N, Nagasaki H, Oiso Y. Glucocorticoids increase NPY gene expression in the arcuate nucleus by inhibiting mTOR signaling in rat hypothalamic organotypic cultures. Peptides 2010; 31:145-9. [PMID: 19818818 DOI: 10.1016/j.peptides.2009.09.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Revised: 09/26/2009] [Accepted: 09/29/2009] [Indexed: 11/22/2022]
Abstract
The mammalian target of rapamycin (mTOR) has been implicated in the regulation of physiological functions such as cell growth and proliferation, and glucocorticoids reportedly inhibit mTOR signaling in peripheral tissues. Recent studies suggest that the mTOR signaling in the hypothalamus plays a critical role in maintaining energy homeostasis. In this study, we examined whether the mTOR signaling in the hypothalamus is involved in the regulation of neuropeptide Y (Npy) gene expression in the arcuate nucleus by glucocorticoids. In the hypothalamic organotypic cultures, the incubation with rapamycin significantly inhibited the mTOR signaling which was shown by decreases in the levels of phosphorylated p70S6K1 and S6. Similar to the action of the mTOR inhibitor rapamycin, dexamethasone (DEX), a synthetic glucocorticoid, also inhibited the mTOR signaling in the hypothalamic explants. Analyses of the explants with in situ hybridization demonstrated that the DEX or rapamycin alone significantly increased Npy gene expression in the arcuate nucleus, but that there were no additive effects of DEX and rapamycin on the expression. These data suggest that glucocorticoids upregulate the Npy gene expression in the arcuate nucleus by inhibiting mTOR signaling, at least in part.
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Affiliation(s)
- Hiroshi Shimizu
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan
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Das UN. Obesity: genes, brain, gut, and environment. Nutrition 2009; 26:459-73. [PMID: 20022465 DOI: 10.1016/j.nut.2009.09.020] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 09/21/2009] [Accepted: 09/27/2009] [Indexed: 01/04/2023]
Abstract
Obesity, which is assuming alarming proportions, has been attributed to genetic factors, hypothalamic dysfunction, and intestinal gut bacteria and an increase in the consumption of energy-dense food. Obesity predisposes to the development of type 2 diabetes mellitus, hypertension, coronary heart disease, and certain forms of cancer. Recent studies have shown that the intestinal bacteria in obese humans and mice differ from those in lean that could trigger a low-grade systemic inflammation. Consumption of a calorie-dense diet that initiates and perpetuates obesity could be due to failure of homeostatic mechanisms that regulate appetite, food consumption, and energy balance. Hypothalamic factors that regulate energy needs of the body, control appetite and satiety, and gut bacteria that participate in food digestion play a critical role in the onset of obesity. Incretins, cholecystokinin, brain-derived neurotrophic factor, leptin, long-chain fatty acid coenzyme A, endocannabinoids and vagal neurotransmitter acetylcholine play a role in the regulation of energy intake, glucose homeostasis, insulin secretion, and pathobiology of obesity and type 2 diabetes mellitus. Thus, there is a cross-talk among the gut, liver, pancreas, adipose tissue, and hypothalamus. Based on these evidences, it is clear that management of obesity needs a multifactorial approach.
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Sangiao-Alvarellos S, Vázquez MJ, Varela L, Nogueiras R, Saha AK, Cordido F, López M, Diéguez C. Central ghrelin regulates peripheral lipid metabolism in a growth hormone-independent fashion. Endocrinology 2009; 150:4562-74. [PMID: 19608647 PMCID: PMC2819740 DOI: 10.1210/en.2009-0482] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
GH plays a major role in the regulation of lipid metabolism and alterations in GH axis elicit major changes in fat distribution and mobilization. For example, in patients with GH deficiency (GHD) or in mice lacking the GH receptor, the percentage of fat is increased. In addition to the direct actions of GH on lipid metabolism, current evidence indicates that ghrelin, a stomach-derived peptide hormone with potent GH secretagogue action, increases lipogenesis in white adipose tissue (WAT) through a hypothalamic-mediated mechanism. Still, the mechanism by which GH tone modulates ghrelin actions on WAT remains unclear. Here we investigated the effect of central ghrelin administration on lipid metabolism in lipogenic tissues (liver and WAT) in the absence of GH, by using a model for the study of GHD, namely the spontaneous dwarf rat, which shows increased body fat. Our data demonstrate that central chronic ghrelin administration regulates adipose lipid metabolism, mainly in a GH-independent fashion, as a result of increased mRNA, protein expression, and activity levels of fatty acid metabolism enzymes. On the contrary, central ghrelin regulates hepatic lipogenesis de novo in a GH-independent fashion but lipid mobilization in a GH-dependent fashion because carnitine palmitoyltransferase 1 was decreased only in wild-type Lewis rats. These findings suggest the existence of a new central nervous system-based neuroendocrine circuit, regulating metabolic homeostasis of adipose tissue. Understanding the molecular mechanism underlying the interplay between GH and ghrelin and their effects on lipid metabolism will provide new strategies for the design and development of suitable drugs for the treatment of GHD, obesity, and its comorbidities.
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Chari M, Lam C, Lam T. Hypothalamic Fatty Acid Sensing in the Normal and Disease States. Front Neurosci 2009. [DOI: 10.1201/9781420067767-c20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Perić - Mataruga V, Mirčić D, Vlahović M, Mrdaković M, Todorović D, Stevanović D, Milošević V. Effects of ghrelin on the feeding behavior of Lymantria dispar L. (Lymantriidae) caterpillars. Appetite 2009; 53:147-50. [DOI: 10.1016/j.appet.2009.05.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 05/12/2009] [Indexed: 10/20/2022]
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49
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Kodomari I, Maruoka T, Yamauchi R, Wada E, Wada K. Ghrelin alters postnatal endocrine secretion and behavior in mouse offspring. Neurochem Int 2009; 54:222-8. [DOI: 10.1016/j.neuint.2008.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/07/2008] [Accepted: 11/22/2008] [Indexed: 11/27/2022]
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50
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Watanabe M, Arima H, Fukushima K, Goto M, Shimizu H, Hayashi M, Banno R, Sato I, Ozaki N, Nagasaki H, Oiso Y. Direct and indirect modulation of neuropeptide Y gene expression in response to hypoglycemia in rat arcuate nucleus. FEBS Lett 2008; 582:3632-8. [DOI: 10.1016/j.febslet.2008.09.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2008] [Revised: 09/22/2008] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
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