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Roberts LD, Hornsby AK, Thomas A, Sassi M, Kinzett A, Hsiao N, David BR, Good M, Wells T, Davies JS. The 5:2 diet does not increase adult hippocampal neurogenesis or enhance spatial memory in mice. EMBO Rep 2023; 24:e57269. [PMID: 37987211 DOI: 10.15252/embr.202357269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/22/2023] Open
Abstract
New neurones are generated throughout life in the mammalian brain in a process known as adult hippocampal neurogenesis (AHN). Since this phenomenon grants a high degree of neuroplasticity influencing learning and memory, identifying factors that regulate AHN may be important for ameliorating age-related cognitive decline. Calorie restriction (CR) has been shown to enhance AHN and improve memory, mediated by the stomach hormone, ghrelin. Intermittent fasting (IF), a dietary strategy offering more flexibility than conventional CR, has also been shown to promote aspects of AHN. The 5:2 diet is a popular form of IF; however, its effects on AHN are not well characterised. To address this, we quantified AHN in adolescent and adult wild-type and ghrelin-receptor-deficient mice following 6 weeks on a 5:2 diet. We report an age-related decline in neurogenic processes. However, the 5:2 diet does not increase AHN nor enhance memory performance, suggesting that this specific form of IF is ineffective in promoting brain plasticity to support learning.
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Affiliation(s)
- Luke D Roberts
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | | | - Alanna Thomas
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | - Martina Sassi
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | - Aimee Kinzett
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | - Nathan Hsiao
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | - Bethan R David
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
| | - Mark Good
- School of Psychology, Cardiff University, Cardiff, UK
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Jeffrey S Davies
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK
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Daniels LJ, Kay D, Marjot T, Hodson L, Ray DW. Circadian regulation of liver metabolism: experimental approaches in human, rodent, and cellular models. Am J Physiol Cell Physiol 2023; 325:C1158-C1177. [PMID: 37642240 PMCID: PMC10861179 DOI: 10.1152/ajpcell.00551.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 06/15/2023] [Accepted: 07/19/2023] [Indexed: 08/31/2023]
Abstract
Circadian rhythms are endogenous oscillations with approximately a 24-h period that allow organisms to anticipate the change between day and night. Disruptions that desynchronize or misalign circadian rhythms are associated with an increased risk of cardiometabolic disease. This review focuses on the liver circadian clock as relevant to the risk of developing metabolic diseases including nonalcoholic fatty liver disease (NAFLD), insulin resistance, and type 2 diabetes (T2D). Many liver functions exhibit rhythmicity. Approximately 40% of the hepatic transcriptome exhibits 24-h rhythms, along with rhythms in protein levels, posttranslational modification, and various metabolites. The liver circadian clock is critical for maintaining glucose and lipid homeostasis. Most of the attention in the metabolic field has been directed toward diet, exercise, and rather little to modifiable risks due to circadian misalignment or disruption. Therefore, the aim of this review is to systematically analyze the various approaches that study liver circadian pathways, targeting metabolic liver diseases, such as diabetes, nonalcoholic fatty liver disease, using human, rodent, and cell biology models.NEW & NOTEWORTHY Over the past decade, there has been an increased interest in understanding the intricate relationship between circadian rhythm and liver metabolism. In this review, we have systematically searched the literature to analyze the various experimental approaches utilizing human, rodent, and in vitro cellular approaches to dissect the link between liver circadian rhythms and metabolic disease.
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Affiliation(s)
- Lorna J Daniels
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Danielle Kay
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Thomas Marjot
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
| | - David W Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
- Kavli Centre for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
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de Sousa ME, Gusmao DO, Dos Santos WO, Moriya HT, de Lima FF, List EO, Kopchick JJ, Donato J. Fasting and prolonged food restriction differentially affect GH secretion independently of GH receptor signaling in AgRP neurons. J Neuroendocrinol 2023:e13254. [PMID: 36964750 DOI: 10.1111/jne.13254] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023]
Abstract
Growth hormone (GH) receptor (GHR) is abundantly expressed in neurons that co-release the agouti-related protein (AgRP) and neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH). Since ARHAgRP/NPY neurons regulate several hypothalamic-pituitary-endocrine axes, this neuronal population possibly modulates GH secretion via a negative feedback loop, particularly during food restriction, when ARHAgRP/NPY neurons are highly active. The present study aims to determine the importance of GHR signaling in ARHAgRP/NPY neurons on the pattern of GH secretion in fed and food-deprived male mice. Additionally, we compared the effect of two distinct situations of food deprivation: 16 h of fasting or four days of food restriction (40% of usual food intake). Overnight fasting strongly suppressed both basal and pulsatile GH secretion. Animals lacking GHR in ARHAgRP/NPY neurons (AgRP∆GHR mice) did not exhibit differences in GH secretion either in the fed or fasted state, compared to control mice. In contrast, four days of food restriction increased GH pulse frequency, basal GH secretion, and pulse irregularity/complexity (measured by sample entropy), whereas pulsatile GH secretion was not affected in both control and AgRP∆GHR mice. Hypothalamic Ghrh mRNA levels were unaffected by fasting or food restriction, but Sst expression increased in acutely fasted mice, but decreased after prolonged food restriction in both control and AgRP∆GHR mice. Our findings indicate that short-term fasting and prolonged food restriction differentially affect the pattern of GH secretion, independently of GHR signaling in ARHAgRP/NPY neurons.
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Affiliation(s)
- Maria E de Sousa
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
| | - Daniela O Gusmao
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
| | - Willian O Dos Santos
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
| | - Henrique T Moriya
- Biomedical Engineering Laboratory, Escola Politecnica, Universidade de Sao Paulo, Sao Paulo, 05508-010, Brazil
| | - Felipe F de Lima
- Biomedical Engineering Laboratory, Escola Politecnica, Universidade de Sao Paulo, Sao Paulo, 05508-010, Brazil
| | - Edward O List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, 45701, USA
| | - John J Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, 45701, USA
| | - Jose Donato
- Department of Physiology and Biophysics, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
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Izmailova O, Kabaliei A, Shynkevych V, Shlykova O, Kaidashev I. PPARG agonist pioglitazone influences diurnal kidney medulla mRNA expression of core clock, inflammation-, and metabolism-related genes disrupted by reverse feeding in mice. Physiol Rep 2022; 10:e15535. [PMID: 36511486 PMCID: PMC9746034 DOI: 10.14814/phy2.15535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023] Open
Abstract
This study examined the influence of PPARG activation by pioglitazone (PG) on the mRNA of core clock, inflammation- and metabolism-related genes in the mouse kidney medulla as well as urinary sodium/potassium excretion rhythms disrupted by reverse feeding. Mice were assigned to daytime feeding and nighttime feeding groups. PG 20 mg/kg was administered at 7 am or 7 pm. On day 8 of the feeding intervention, mice were killed at noon and midnight. Kidney medulla expression of Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, Per2, Nfe2l2, Pparg, and Scnn1g was determined by qRT PCR. We measured urinary K+ , Na+ , urine volume, food, and H2 O intake. The reverse feeding uncoupled the peripheral clock gene rhythm in mouse kidney tissues. It was accompanied by a decreased expression of Nfe2l2 and Pparg as well as an increased expression of Rela and Scnn1g. These changes in gene expressions concurred with an increase in urinary Na+ , K+ , water excretion, microcirculation disorders, and cell loss, especially in distal tubules. PG induced the restoration of diurnal core clock gene expression as well as Nfe2l2, Pparg, Scnn1g mRNA, and decreased Rela expressions, stimulating Na+ reabsorption and inhibiting K+ excretion. PG intake at 7 pm was more effective than at 7 am.
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PPAR-γ Agonist Pioglitazone Restored Mouse Liver mRNA Expression of Clock Genes and Inflammation-Related Genes Disrupted by Reversed Feeding. PPAR Res 2022; 2022:7537210. [PMID: 35663475 PMCID: PMC9162826 DOI: 10.1155/2022/7537210] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/27/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Introduction The master clock, which is located in the suprachiasmatic nucleus (SCN), harmonizes clock genes present in the liver to synchronize life rhythms and bioactivity with the surrounding environment. The reversed feeding disrupts the expression of clock genes in the liver. Recently, a novel role of PPAR-γ as a regulator in correlating circadian rhythm and metabolism was demonstrated. This study examined the influence of PPAR-γ agonist pioglitazone (PG) on the mRNA expression profile of principle clock genes and inflammation-related genes in the mouse liver disrupted by reverse feeding. Methods Mice were randomly assigned to daytime-feeding and nighttime-feeding groups. Mice in daytime-feeding groups received food from 7 AM to 7 PM, and mice in nighttime-feeding groups received food from 7 PM to 7 AM. PG was administered in the dose of 20 mg/kg per os as aqueous suspension 40 μl at 7 AM or 7 PM. Each group consisted of 12 animals. On day 8 of the feeding intervention, mice were sacrificed by cervical dislocation at noon (05 hours after light onset (HALO)) and midnight (HALO 17). Liver expressions of Bmal1, Clock, Rev-erb alpha, Cry1, Cry2, Per1, Per2, Cxcl5, Nrf2, and Ppar-γ were determined by quantitative reverse transcription PCR. Liver expression of PPAR-γ, pNF-κB, and IL-6 was determined by Western blotting. Glucose, ceruloplasmin, total cholesterol, triglyceride concentrations, and ALT and AST activities were measured in sera by photometric methods. The null hypothesis tested was that PG and the time of its administration have no influence on the clock gene expression impaired by reverse feeding. Results Administration of PG at 7 AM to nighttime-feeding mice did not reveal any influence on the expression of the clock or inflammation-related genes either at midnight or at noon. In the daytime-feeding group, PG intake at 7 PM led to an increase in Per2 and Rev-erb alpha mRNA at noon, an increase in Ppar-γ mRNA at midnight, and a decrease in Nfκb (p65) mRNA at noon. In general, PG administration at 7 PM slightly normalized the impaired expression of clock genes and increased anti-inflammatory potency impaired by reversed feeding. This pattern was supported by biochemical substrate levels—glucose, total cholesterol, ALT, and AST activities. The decrease in NF-κB led to the inhibition of serum ceruloplasmin levels as well as IL-6 in liver tissue. According to our data, PG intake at 7 PM exerts strong normalization of clock gene expression with a further increase in Nrf2 and, especially, Ppar-γ and PPAR-γ expression with inhibition of Nfκb and pNF-κB expression in daytime-feeding mice. These expression changes resulted in decreased hyperglycemia, hypercholesterolemia, ALT, and AST activities. Thus, PG had a potent chronopharmacological effect when administered at 7 PM to daytime-feeding mice. Conclusions Our study indicates that reversed feeding induced the disruption of mouse liver circadian expression pattern of clock genes accompanied by increasing Nfκb and pNF-κB and IL-6 expression and decreasing Nrf2 and PPAR-γ. Administration of PG restored the clock gene expression profile and decreased Nfκb, pNF-κB, and IL-6, as well as increased Nrf2, Ppar-γ, and PPAR-γ expression. PG intake at 7 PM was more effective than at 7 AM in reversed feeding mice.
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Sheep as a model for neuroendocrinology research. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:1-34. [PMID: 35595346 DOI: 10.1016/bs.pmbts.2022.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animal models remain essential to understand the fundamental mechanisms of physiology and pathology. Particularly, the complex and dynamic nature of neuroendocrine cells of the hypothalamus make them difficult to study. The neuroendocrine systems of the hypothalamus are critical for survival and reproduction, and are highly conserved throughout vertebrate evolution. Their roles in controlling body metabolism, growth and body composition, stress, electrolyte balance, and reproduction, have been intensively studied, and have yielded groundbreaking discoveries. Many of these discoveries would not have been feasible without the use of the domestic sheep (Ovis aries). The sheep has been used for decades to study the neuroendocrine systems of the hypothalamus and has become a model for human neuroendocrinology. The aim of this chapter is to review some of the profound biomedical discoveries made possible by the use of sheep. The advantages and limitations of sheep as a neuroendocrine model will be discussed. While no animal model can perfectly recapitulate a human disease or condition, sheep are invaluable for enabling manipulations not possible in human subjects and isolating physiologic variables to garner insight into neuroendocrinology and associated pathologies.
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Tilston TW, Brown RD, Wateridge MJ, Arms-Williams B, Walker JJ, Sun Y, Wells T. A Novel Automated System Yields Reproducible Temporal Feeding Patterns in Laboratory Rodents. J Nutr 2019; 149:1674-1684. [PMID: 31287142 PMCID: PMC6736427 DOI: 10.1093/jn/nxz116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/23/2019] [Accepted: 05/07/2019] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The impact of temporal feeding patterns remains a major unanswered question in nutritional science. Progress has been hampered by the absence of a reliable method to impose temporal feeding in laboratory rodents, without the confounding influence of food-hoarding behavior. OBJECTIVE The aim of this study was to develop and validate a reliable method for supplying crushed diets to laboratory rodents in consistent, relevant feeding patterns for prolonged periods. METHODS We programmed our experimental feeding station to deliver a standard diet [StD; Atwater Fuel Energy (AFE) 13.9% fat] or high-fat diet (HFD; AFE 45% fat) during nocturnal grazing [providing 1/24th of the total daily food intake (tdF/I) of ad libitum-fed controls every 30 min] and meal-fed (3 × 1-h periods of ad libitum feeding) patterns in male rats (Sprague-Dawley: 4 wk old, 72-119 g) and mice [C57/Bl6J wild-type (WT): 6 mo old, 29-37 g], and ghrelin-null littermates (Ghr-/-; 27-34 g). RESULTS Grazing yielded accurate, consistent feeding events in rats, with an approximately linear rise in nocturnal cumulative food intake [tdF/I (StD): 97.4 ± 1.5% accurate compared with manual measurement; R2 = 0.86; tdF/I (HFD): 99.0 ± 1.4% accurate; R2 = 0.86]. Meal-feeding produced 3 nocturnal meals of equal size and duration in StD-fed rats (tdF/I: 97.4 ± 0.9% accurate; R2 = 0.90), whereas the second meal size increased progressively in HFD-fed rats (44% higher on day 35 than on day 14; P < 0.01). Importantly, cumulative food intake in grazing and meal-fed rats was identical. Similar results were obtained in WT mice except that less restricted grazing induced hyperphagia (compared with meal-fed WT mice; P < 0.05 from day 1). This difference was abolished in Ghr-/- mice, with meal initiation delayed and meal duration enhanced. Neither pattern elevated corticosterone secretion in rats, but meal-feeding aligned ultradian pulses. CONCLUSIONS We have established a consistent, measurable, researcher-defined, stress-free method for imposing temporal feeding patterns in rats and mice. This approach will facilitate progress in understanding the physiologic impact of feeding patterns.
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Affiliation(s)
- Thomas W Tilston
- Neuroscience and Mental Health Research Institute and School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Richard D Brown
- Neuroscience and Mental Health Research Institute and School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Matthew J Wateridge
- Neuroscience and Mental Health Research Institute and School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Bradley Arms-Williams
- Neuroscience and Mental Health Research Institute and School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Jamie J Walker
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
- Wellcome Trust Centre for Biomedical Modelling and Analysis, University of Exeter, Exeter, United Kingdom
- EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter, United Kingdom
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Yuxiang Sun
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Timothy Wells
- Neuroscience and Mental Health Research Institute and School of Biosciences, Cardiff University, Cardiff, United Kingdom
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Teixeira GP, Barreto ADCF, Mota MC, Crispim CA. Caloric midpoint is associated with total calorie and macronutrient intake and body mass index in undergraduate students. Chronobiol Int 2019; 36:1418-1428. [DOI: 10.1080/07420528.2019.1652830] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | | | - Maria Carliana Mota
- Health Sciences, Faculty of Medicine, Federal University of Uberlândia, Uberlândia, Brazil
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El Cheikh Hussein L, Mollard P, Bonnefont X. Molecular and Cellular Networks in The Suprachiasmatic Nuclei. Int J Mol Sci 2019; 20:ijms20082052. [PMID: 31027315 PMCID: PMC6514755 DOI: 10.3390/ijms20082052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 12/20/2022] Open
Abstract
Why do we experience the ailments of jetlag when we travel across time zones? Why is working night-shifts so detrimental to our health? In other words, why can’t we readily choose and stick to non-24 h rhythms? Actually, our daily behavior and physiology do not simply result from the passive reaction of our organism to the external cycle of days and nights. Instead, an internal clock drives the variations in our bodily functions with a period close to 24 h, which is supposed to enhance fitness to regular and predictable changes of our natural environment. This so-called circadian clock relies on a molecular mechanism that generates rhythmicity in virtually all of our cells. However, the robustness of the circadian clock and its resilience to phase shifts emerge from the interaction between cell-autonomous oscillators within the suprachiasmatic nuclei (SCN) of the hypothalamus. Thus, managing jetlag and other circadian disorders will undoubtedly require extensive knowledge of the functional organization of SCN cell networks. Here, we review the molecular and cellular principles of circadian timekeeping, and their integration in the multi-cellular complexity of the SCN. We propose that new, in vivo imaging techniques now enable to address these questions directly in freely moving animals.
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Affiliation(s)
- Lama El Cheikh Hussein
- Institut de Génomique Fonctionnelle (IGF), University Montpellier, CNRS, INSERM, 34094 Montpellier, France.
| | - Patrice Mollard
- Institut de Génomique Fonctionnelle (IGF), University Montpellier, CNRS, INSERM, 34094 Montpellier, France.
| | - Xavier Bonnefont
- Institut de Génomique Fonctionnelle (IGF), University Montpellier, CNRS, INSERM, 34094 Montpellier, France.
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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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Golding DM, Rees DJ, Davies JR, Relkovic D, Furby HV, Guschina IA, Hopkins AL, Davies JS, Resnick JL, Isles AR, Wells T. Paradoxical leanness in the imprinting-centre deletion mouse model for Prader-Willi syndrome. J Endocrinol 2017; 232:123-135. [PMID: 27799465 PMCID: PMC5118940 DOI: 10.1530/joe-16-0367] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 10/31/2016] [Indexed: 01/09/2023]
Abstract
Prader-Willi syndrome (PWS), a neurodevelopmental disorder caused by loss of paternal gene expression from 15q11-q13, is characterised by growth retardation, hyperphagia and obesity. However, as single gene mutation mouse models for this condition display an incomplete spectrum of the PWS phenotype, we have characterised the metabolic impairment in a mouse model for 'full' PWS, in which deletion of the imprinting centre (IC) abolishes paternal gene expression from the entire PWS cluster. We show that PWS-ICdel mice displayed postnatal growth retardation, with reduced body weight, hyperghrelinaemia and marked abdominal leanness; proportionate retroperitoneal, epididymal/omental and inguinal white adipose tissue (WAT) weights being reduced by 82%, 84% and 67%, respectively. PWS-ICdel mice also displayed a 48% reduction in proportionate interscapular brown adipose tissue (isBAT) weight with significant 'beiging' of abdominal WAT, and a 2°C increase in interscapular surface body temperature. Maintenance of PWS-ICdel mice under thermoneutral conditions (30°C) suppressed the thermogenic activity in PWS-ICdel males, but failed to elevate the abdominal WAT weight, possibly due to a normalisation of caloric intake. Interestingly, PWS-ICdel mice also showed exaggerated food hoarding behaviour with standard and high-fat diets, but despite becoming hyperphagic when switched to a high-fat diet, PWS-ICdel mice failed to gain weight. This evidence indicates that, unlike humans with PWS, loss of paternal gene expression from the PWS cluster in mice results in abdominal leanness. Although reduced subcutaneous insulation may lead to exaggerated heat loss and thermogenesis, abdominal leanness is likely to arise from a reduced lipid storage capacity rather than increased energy utilisation in BAT.
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Affiliation(s)
| | - Daniel J Rees
- Institute of Life SciencesCollege of Medicine, Swansea University, Swansea, UK
| | - Jennifer R Davies
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Dinko Relkovic
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Hannah V Furby
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | | | | | - Jeffrey S Davies
- Institute of Life SciencesCollege of Medicine, Swansea University, Swansea, UK
| | - James L Resnick
- Center for Mammalian GeneticsUniversity of Florida, College of Medicine, Gainesville, Florida, USA
| | - Anthony R Isles
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Timothy Wells
- School of BiosciencesCardiff University, Cardiff, UK
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Go EH, Lee SH. Effect of Long Term Reverse Feeding on the Reproductive and Non-reproductive Tissues in Male Mice. Dev Reprod 2015; 18:161-6. [PMID: 25949185 PMCID: PMC4282209 DOI: 10.12717/dr.2014.18.3.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 08/11/2014] [Accepted: 08/18/2014] [Indexed: 01/17/2023]
Abstract
Previously, we demonstrated that the shift and/or restriction of feeding time during relatively short-term period (4 weeks) could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. We also found that the reverse feeding (RF) schedule (up to 8 weeks) might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. In the present study, we extended the RF time regimen up to 12 weeks, and measured the reproductive tissue weights. After 4 and 8 weeks of RF, the weights of epididymis were not significantly different. After 12 weeks, however, epididymis weights of RF animals were significantly different (CON 12W : RF 12W = 48.26±0.62 mg : 44.05±1.57 mg, p<0.05). After 4 and 12 weeks of feeding, seminal vesicle weights of RF animals were significantly decreased (CON 4W : RF 4W = 79.36±8.34 mg : 46.28±2.43 mg, p<0.001; CON 12W : RF 12W = 72.04±3.76 mg : 46.71±2.27 mg, p<0.001, respectively). Prostate weights were not changed by RF. Kidney and spleen weights of RF animals were significantly different on weeks 4 and 12 (Kidney, CON 4W : RF 4W = 249.72±4.20 mg : 228.41±3.03 mg, p<0.001; CON 12W : RF 12W = 309.15±7.49 mg : 250.72±6.13 mg, p<0.001, respectively, Spleen, CON 4W : RF 4W = 111.26±3.76 mg : 96.88±4.69 mg, p<0.05; CON 12W : RF 12W = 123.93±10.72 mg : 94.68±5.65 mg, p<0.05, respectively). Histology analysis of seminal vesicle revealed that the thinner epithelial cell layers, reduced complexities of swollen papilla folding in the exocrine glands on weeks 4 and 12 of RF. There was no histological difference between control and RF group on week 8. The present study indicates that up to 12 weeks RF induced differential changes in tissue weights of male mice. In particular, seminal vesicle, kidney and spleen seemed to temporarily adapted to the RF-induced metabolic stress on week 8 of feeding schedule. These results confirmed the our previous study that the RF might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues such as epididymis and seminal vesicle as well as non-reproductive tissues such as kidney and spleen. Further studies will be needed to achieve a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.
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Affiliation(s)
- Eun Hye Go
- Department of Life Science, Sangmyung University, Seoul 110-743, Korea
| | - Sung-Ho Lee
- Department of Life Science, Sangmyung University, Seoul 110-743, Korea
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Actions of NPY, and its Y1 and Y2 receptors on pulsatile growth hormone secretion during the fed and fasted state. J Neurosci 2015; 34:16309-19. [PMID: 25471570 DOI: 10.1523/jneurosci.4622-13.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The hypothalamic NPY system plays an important role in regulating food intake and energy expenditure. Different biological actions of NPY are assigned to NPY receptor subtypes. Recent studies demonstrated a close relationship between food intake and growth hormone (GH) secretion; however, the mechanism through which endogenous NPY modulates GH release remains unknown. Moreover, conclusive evidence demonstrating a role for NPY and Y-receptors in regulating the endogenous pulsatile release of GH does not exist. We used genetically modified mice (germline Npy, Y1, and Y2 receptor knock-out mice) to assess pulsatile GH secretion under both fed and fasting conditions. Deletion of NPY did not impact fed GH release; however, it reversed the fasting-induced suppression of pulsatile GH secretion. The recovery of GH secretion was associated with a reduction in hypothalamic somatotropin release inhibiting factor (Srif; somatostatin) mRNA expression. Moreover, observations revealed a differential role for Y1 and Y2 receptors, wherein the postsynaptic Y1 receptor suppresses GH secretion in fasting. In contrast, the presynaptic Y2 receptor maintains normal GH output under long-term ad libitum-fed conditions. These data demonstrate an integrated neural circuit that modulates GH release relative to food intake, and provide essential information to address the differential roles of Y1 and Y2 receptors in regulating the release of GH under fed and fasting states.
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Arellanes-Licea EDC, Báez-Ruiz A, Carranza ME, Arámburo C, Luna M, Díaz-Muñoz M. Daily patterns and adaptation of the ghrelin, growth hormone and insulin-like growth factor-1 system under daytime food synchronisation in rats. J Neuroendocrinol 2014; 26:282-95. [PMID: 24617825 DOI: 10.1111/jne.12145] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 02/07/2014] [Accepted: 03/06/2014] [Indexed: 11/29/2022]
Abstract
Daytime restricted feeding promotes the re-alignment of the food entrained oscillator (FEO). Endocrine cues which secretion is regulated by the transition of fasting and feeding cycles converge in the FEO. The present study aimed to investigate the ghrelin, growth hormone (GH) and insulin-like growth factor (IGF)-1 system because their release depends on rhythmic and nutritional factors, and the output from the system influences feeding and biochemical status. In a daily sampling approach, rats that were fed ad lib. were compared with rats on a reversed (daytime) and restricted feeding schedule by 3 weeks (dRF; food access for 2 h), also assessing the effect of acute fasting and refeeding. We undertook measurements of clock protein BMAL1 and performed somatometry of peripheral organs and determined the concentration of total, acylated and unacylated ghrelin, GH and IGF-1 in both serum and in its main synthesising organs. During dRF, BMAL1 expression was synchronised to mealtime in hypophysis and liver; rats exhibited acute hyperphagia, stomach distension with a slow emptying, a phase shift in liver mass towards the dark period and decrease in mass perigonadal white adipose tissue. Total ghrelin secretion during the 24-h period increased in the dRF group as a result of elevation of the unacylated form. By contrast, GH and IGF-1 serum concentration fell, with a modification of GH daily pattern after mealtime. In the dRF group, ghrelin content in the stomach and pituitary GH content decreased, whereas hepatic IGF-1 remained equal. The daily patterns and synthesis of these hormones had a rheostatic adaptation. The endocrine adaptive response elicited suggests that it may be associated with the regulation of metabolic, behavioural and physiological processes during the paradigm of daytime restricted feeding and associated FEO activity.
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Affiliation(s)
- E del C Arellanes-Licea
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
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Metabolic consequences of timed feeding in mice. Physiol Behav 2014; 128:188-201. [DOI: 10.1016/j.physbeh.2014.02.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/29/2014] [Accepted: 02/06/2014] [Indexed: 01/02/2023]
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Uncoupling of Peripheral and Master Clock Gene Rhythms by Reversed Feeding Leads to an Exacerbated Inflammatory Response After Polymicrobial Sepsis in Mice. Shock 2014; 41:214-21. [DOI: 10.1097/shk.0000000000000094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Salgado-Delgado RC, Saderi N, Basualdo MDC, Guerrero-Vargas NN, Escobar C, Buijs RM. Shift work or food intake during the rest phase promotes metabolic disruption and desynchrony of liver genes in male rats. PLoS One 2013; 8:e60052. [PMID: 23565183 PMCID: PMC3615006 DOI: 10.1371/journal.pone.0060052] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/20/2013] [Indexed: 12/11/2022] Open
Abstract
In the liver, clock genes are proposed to drive metabolic rhythms. These gene rhythms are driven by the suprachiasmatic nucleus (SCN) mainly by food intake and via autonomic and hormonal pathways. Forced activity during the normal rest phase, induces also food intake, thus neglecting the signals of the SCN, leading to conflicting time signals to target tissues of the SCN. The present study explored in a rodent model of night-work the influence of food during the normal sleep period on the synchrony of gene expression between clock genes and metabolic genes in the liver. Male Wistar rats were exposed to forced activity for 8 h either during the rest phase (day) or during the active phase (night) by using a slow rotating wheel. In this shift work model food intake shifts spontaneously to the forced activity period, therefore the influence of food alone without induced activity was tested in other groups of animals that were fed ad libitum, or fed during their rest or active phase. Rats forced to be active and/or eating during their rest phase, inverted their daily peak of Per1, Bmal1 and Clock and lost the rhythm of Per2 in the liver, moreover NAMPT and metabolic genes such as Pparα lost their rhythm and thus their synchrony with clock genes. We conclude that shift work or food intake in the rest phase leads to desynchronization within the liver, characterized by misaligned temporal patterns of clock genes and metabolic genes. This may be the cause of the development of the metabolic syndrome and obesity in individuals engaged in shift work.
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Affiliation(s)
- Roberto C Salgado-Delgado
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Distrito Federal, México
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Gimble JM, Sutton GM, Ptitsyn AA, Floyd ZE, Bunnell BA. Circadian rhythms in adipose tissue: an update. Curr Opin Clin Nutr Metab Care 2011; 14:554-61. [PMID: 21986477 DOI: 10.1097/mco.0b013e32834ad94b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Over the past decade, evidence has accumulated from basic science, clinical and epidemiological studies linking circadian mechanisms to adipose tissue biology and its related comorbidities, diabetes, metabolic syndrome and obesity. This review highlights recent in-vitro and in-vivo findings from murine, human and model organism studies. RECENT FINDINGS High-fat diets attenuate circadian mechanisms in murine adipose depots and these effects appear to be due to obesity rather than hyperglycemia. Deletion of circadian regulatory genes such as AMPK1 and nocturnin alter the circadian biology of adipose tissue. Unlike the mouse, circadian gene oscillation in human adipose tissue appears to be independent of BMI and diabetes status, suggesting that circadian mechanistic variation occurs across species. Clues for future directions in this emerging field come from studies of the hibernation and torpor state in mammals and infection models involving the Drosophila metabolic organ or 'fat body'. SUMMARY There is a growing consensus that circadian rhythms and metabolism are tightly regulated in adipose tissue and peripheral metabolic organs. Although central mechanisms are critical, autonomous clocks exist within the adipocytes themselves. Future circadian advances are likely to result from the studies of adipose tissue-specific gene deletions.
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Affiliation(s)
- Jeffrey M Gimble
- Stem Cell Biology Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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