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Effects of Helicobacter pylori Infection on Ghrelin and Insulin-like Growth Factor 1 Secretion in Children with Idiopathic Short Stature. J Clin Med 2022; 11:jcm11195868. [PMID: 36233735 PMCID: PMC9572010 DOI: 10.3390/jcm11195868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
Abstract
Background: A diagnosis of "idiopathic short stature" (ISS) in a child means that the cause of the disease has not been established, although there are certainly some unknown factors that contributed to its occurrence. Ghrelin and leptin are important in controlling food intake; ghrelin is also a growth hormone (GH) stimulator. Both enterohormones are produced in the stomach and their secretion may be affected by a Helicobacter pylori (H. pylori) infection. Methods: Our study included a group of 61 children (53 prepubertal and 8 peripubertal) with ISS, without any gastrointestinal tract symptoms but in whom the histopathological evaluation of stomach tissue was made during gastroscopy to diagnose H. pylori infection. In each child, fasting ghrelin, leptin and IGF-1 concentrations, and GH levels in two stimulation tests were assessed. Results: H. pylori infection was confirmed in 24.6% of the children. Ghrelin and IGF-1 concentrations were significantly lower in H. pylori-positive than H. pylori-negative children (this was more noticeable in prepubertal subgroups), however there was not a discrepancy in regards to GH concentrations in stimulation tests, leptin levels or the nutritional state between groups. Conclusions: Short children, infected by H. pylori seem to have lower ghrelin and IGF-1 concentrations than children without infection, this may be the reason for a worse growth rate in this subgroup.
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Samy W, El Gebaly A, Ahmed NH, Talaat A. Ghrelin polymorphism/TRPV1 receptor expression in Egyptian IBS patients. Cytokine 2022; 152:155827. [PMID: 35182895 DOI: 10.1016/j.cyto.2022.155827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 11/07/2021] [Accepted: 02/06/2022] [Indexed: 11/03/2022]
Abstract
INTRODUCTION/OBJECTIVE Irritable bowel syndrome is a functional gastrointestinal disorder. Ghrelin is a peptide hormone which affects gastrointestinal motility. We have studied the association between ghrelin gene polymorphism, ghrelin expression, and their effect on TRPV1 correlating this with IBS manifestations in the Egyptian patients. METHODS Participants included 60 IBS patients meeting the Rome III criteria and 60 controls similar in age and gender were recruited. Whole blood samples were used for genotyping of Ghrelin polymorphisms rs696217. Colonic biopsies were processed for mRNA expression analysis of ghrelin and TRPV1. RESULTS The rs696217 GG genotype frequency was higher in patients (78.3%) compared to controls (57%). According to GT\TT genotype there was significant difference between IBS and control group: 21.7%, 43% respectively (p = 0.0126). In allele frequency distribution, G allele in the IBS group was 87.5% while in the control group was 74%.T allele presents in 12.5% of IBS patients and 26% in the control group (p = 0.010). The genotype frequencies did not significantly differ between IBS subtypes. TRPV1 mRNA levels in were significantly increased in IBS patients than in controls (p < 0.05), while GHRL mRNA expression was significantly decreased (p < 0.05). The IBS-C group showed significantly higher levels of TRPV1 and lower levels of GHRL mRNA expression (p < 0.05) CONCLUSIONS: we showed that ghrelin rs696217 might have a role in IBS, as those patients carrying the GG genotype showed a significant decrease in ghrelin mRNA expression, with a subsequent significant increase in TRPV1 gene expression, and could explain some of the IBS manifestations.
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Affiliation(s)
- Walaa Samy
- Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Egypt.
| | - Ahmed El Gebaly
- Department of Tropical Medicine, Faculty of Medicine, Zagazig University, Egypt
| | - Nabila H Ahmed
- Department of Tropical Medicine, Faculty of Medicine, Zagazig University, Egypt
| | - Aliaa Talaat
- Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Egypt
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Lewiński A, Karbownik-Lewińska M, Wieczorek-Szukała K, Stasiak M, Stawerska R. Contribution of Ghrelin to the Pathogenesis of Growth Hormone Deficiency. Int J Mol Sci 2021; 22:9066. [PMID: 34445772 PMCID: PMC8396656 DOI: 10.3390/ijms22169066] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023] Open
Abstract
In this review we described the interactions between ghrelin and the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis in children and adults with growth hormone deficiency (GHD). A possible involvement of these interactions in the pathogenesis of unexplained cases of GHD was suggested. Current research provides more and more details to the knowledge on the circadian rhythm of ghrelin. We gathered reports on the decreasing effect of Helicobacter pylori-related chronic gastritis on the number of ghrelin immunopositive cells and the consequent decrease in ghrelin serum concentration. The gastrointestinal tract microflora modification of the ghrelin action, by the mechanism of molecular mimicry, was also stressed. Moreover, the mutual relationships between ghrelin and the TSH-FT4/FT3 axis in growth and metabolic processes are described. It is to be recalled that FT4 and FT3 exert a permissive impact on IGF-1 action and, in turn, GH, in reaction mediated by IGF-1, enhances the monodeiodination of FT4 to FT3. Finally, we discussed the latest attempts to use the GH secretagogue receptor (GHS-R) analogues for possible diagnostic and therapeutic purposes.
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Affiliation(s)
- Andrzej Lewiński
- Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, 93-338 Lodz, Poland;
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
| | - Małgorzata Karbownik-Lewińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
- Department of Oncological Endocrinology, Medical University of Lodz, 90-419 Lodz, Poland
| | | | - Magdalena Stasiak
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
| | - Renata Stawerska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (M.K.-L.); (M.S.); (R.S.)
- Department of Paediatric Endocrinology, Medical University of Lodz, 90-419 Lodz, Poland
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Adamczewska K, Adamczewski Z, Łupińska A, Lewiński A, Stawerska R. Strong Positive Correlation between TSH and Ghrelin in Euthyroid Non-Growth Hormone-Deficient Children with Short Stature. Molecules 2020; 25:E3912. [PMID: 32867237 PMCID: PMC7503826 DOI: 10.3390/molecules25173912] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/19/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022] Open
Abstract
The growth processes in children depend on the proper functioning of some hormones and growth factors. Recently, a positive correlation between ghrelin and TSH (thyroid stimulating hormone) in patients with hyper- and hypothyroidism was proved. Moreover, in hypothyroid rats with high ghrelin concentration, growth hormone (GH) and insulin-like growth factor I (IGF-I) secretion was suppressed. We analyzed these relationships in euthyroid prepubertal children with idiopathic short stature (ISS). The analysis comprised concentration of ghrelin, GH in stimulating tests and during the night, as well as IGF-I, TSH, free thyroxine (FT4) and free triiodothyronine (FT3) in 85 children with ISS (36 girls, 49 boys) aged 9.65 ± 3.02 years (mean ± SD). A strong positive correlation between ghrelin and TSH was confirmed (r = +0.44, p < 0.05). A higher ghrelin but lower nocturnal GH and lower IGF-I were observed in children with higher normal TSH concentration than those in children with lower normal TSH. Interestingly, alterations of TSH level were without any impact on FT4 and FT3 concentrations. Summing up, in ISS prepubertal euthyroid children, ghrelin and TSH secretion are closely related. On the other hand, the higher the TSH, the lower the nocturnal GH and IGF-I levels. The contribution of the above findings in deterioration of growth processes requires further studies.
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Affiliation(s)
- Katarzyna Adamczewska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (K.A.); (Z.A.); (A.Ł.); (A.L.)
| | - Zbigniew Adamczewski
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (K.A.); (Z.A.); (A.Ł.); (A.L.)
- Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, 93-338 Lodz, Poland
| | - Anna Łupińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (K.A.); (Z.A.); (A.Ł.); (A.L.)
| | - Andrzej Lewiński
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (K.A.); (Z.A.); (A.Ł.); (A.L.)
- Department of Endocrinology and Metabolic Diseases, Medical University of Lodz, 93-338 Lodz, Poland
| | - Renata Stawerska
- Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital—Research Institute, 93-338 Lodz, Poland; (K.A.); (Z.A.); (A.Ł.); (A.L.)
- Department of Pediatric Endocrinology, Medical University of Lodz, 93-338 Lodz, Poland
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Stawerska R, Kolasa-Kicińska M, Łupińska A, Hilczer M, Lewiński A. Comparison of nocturnal and morning ghrelin concentration in children with growth hormone deficiency and with idiopathic short stature. Chronobiol Int 2020; 37:1629-1635. [PMID: 32779492 DOI: 10.1080/07420528.2020.1797765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ghrelin - a growth hormone (GH) secretagogue - presents a circadian rhythm with higher nocturnal than diurnal concentration (similar to GH). However, daily ghrelin production depends on food intake and nutritional state; it is increased in the fasting state and decreased after a meal. Since most past research concerning short stature children has relied on the morning ghrelin concentration for analyses, we decided to assess ghrelin concentration at the 60th and 90th minute after falling asleep and in the morning at 06:00 h, shortly after waking up from nighttime sleep (after 12 h of fasting). We compared these ghrelin concentrations to determine differences between nocturnal and morning ghrelin release in short children, both with idiopathic short stature (ISS) and growth hormone deficiency (GHD). We also analyzed the correlation between the nocturnal and morning ghrelin concentrations with nocturnal GH concentrations, measured at the same time points, as well as with maximal GH concentration, achieved by stimulation tests, and with the insulin-like growth factor I (IGF-I). The ghrelin and GH concentration 60th and 90th minute after falling asleep, as well as fasting morning ghrelin and IGF-I concentrations, were measured in 19 (n = 10 ISS and n = 9 GHD) prepubertal short children (7 girls and 12 boys), aged 10.36 ± 3.06 y. Differences between the nocturnal and morning ghrelin concentrations were analyzed by the Wilcoxon matched-pairs signed-rank test. Typical regression and correlation analyses were used to assess relationships among parametric data for other analyses. The Wilcoxon test showed ghrelin concentration is significantly higher in the morning than both at the 60th and 90th minute after falling asleep time points (in ISS and GHD). A significant correlation was observed: a) positive - between nocturnal ghrelin (both at the 60th and 90th minute) and morning ghrelin concentrations; b) positive - between ghrelin at the 60th minute and nocturnal GH concentrations (both at the 60th and 90th minute); c) negative - between ghrelin at the 60th minute and IGF-I concentrations; and d) negative - between body mass index and ghrelin concentrations at the 60th and 90th minute. We conclude: 1) in short children, both with GHD and with ISS, morning ghrelin level reflects its nocturnal concentration; however, it is significantly higher than the nocturnal ones. There is no significant difference between the measurement of ghrelin concentration at night at the 60th or 90th minute after falling asleep; 2) morning ghrelin concentration is affected by the hunger and satiety; therefore, it appears that nocturnal measurements better reflect the pool of hormone responsible for stimulation of GH and IGF-I secretion, especially since positive correlation between nocturnal ghrelin and nocturnal GH secretion was noted; 3) it seems that a higher body mass index is an additional independent factor, associated mainly with lower nocturnal (but not morning) ghrelin secretion.
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Affiliation(s)
- Renata Stawerska
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute , Lodz, Poland.,Department of Pediatric Endocrinology, Medical University of Lodz , Lodz, Poland
| | - Marzena Kolasa-Kicińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute , Lodz, Poland
| | - Anna Łupińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute , Lodz, Poland
| | - Maciej Hilczer
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute , Lodz, Poland
| | - Andrzej Lewiński
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute , Lodz, Poland.,Department of Endocrinology and Metabolic Diseases, Medical University of Lodz , Lodz, Poland
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Huynh DN, Elimam H, Bessi VL, Ménard L, Burelle Y, Granata R, Carpentier AC, Ong H, Marleau S. A Linear Fragment of Unacylated Ghrelin (UAG 6-13) Protects Against Myocardial Ischemia/Reperfusion Injury in Mice in a Growth Hormone Secretagogue Receptor-Independent Manner. Front Endocrinol (Lausanne) 2018; 9:798. [PMID: 30692964 PMCID: PMC6340090 DOI: 10.3389/fendo.2018.00798] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/19/2018] [Indexed: 12/29/2022] Open
Abstract
Unacylated ghrelin (UAG), the most abundant form of ghrelin in circulation, has been shown to exert cardioprotective effect in experimental cardiopathies. The present study aimed to investigate the cardioprotective effect of a linear bioactive fragment of UAG against myocardial ischemia-induced injury and dysfunction in C57BL/6 wild type mice and the mechanisms involved. Treatments were administered at doses of 100 (UAG), 1,000 and 3,000 (UAG6-13) nmol/kg at 12 h interval during 14 days prior to 30 min left coronary artery ligation and reperfusion for a period of 6 or 48 h. The infarct area was decreased in a dose-dependent manner at 48 h of reperfusion, with a reduction of 54% at the highest dose of UAG6-13 tested. Myocardial hemodynamics were improved as demonstrated by an increase in cardiac output, maximum first derivative of left ventricular pressure, and preload recruitable stroke work, a load-independent contractility index. Six hours after reperfusion, circulating levels of IL-6 and TNF-α pro-inflammatory cytokines were reduced, and the effect was maintained at 48 h for TNF-α. 5' AMP-activated protein kinase (AMPK) was activated, while acetyl-CoA carboxylase (ACC) activity was inhibited, along with a decrease in apoptotic protein levels. In isolated hearts, the effect of UAG6-13 was unaffected by the presence of D-Lys3-GHRP-6, a ghrelin receptor (GHSR1a) antagonist, suggesting that the peptide acted through a GHSR1a-independent pathway. The results support the therapeutic application of UAG bioactive peptide fragments against myocardial ischemia/reperfusion injury.
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Affiliation(s)
- David N. Huynh
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
| | - Hanan Elimam
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
- Faculty of Pharmacy, University of Sadat City, Sadat, Egypt
| | - Valérie L. Bessi
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
| | - Liliane Ménard
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
| | - Yan Burelle
- Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Riccarda Granata
- Department of Medical Science, University of Turin, Turin, Italy
| | - André C. Carpentier
- Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Huy Ong
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Huy Ong
| | - Sylvie Marleau
- Faculté de pharmacie, Université de Montréal, Montréal, QC, Canada
- Sylvie Marleau
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Recinella L, Leone S, Ferrante C, Chiavaroli A, Shohreh R, Di Nisio C, Vacca M, Orlando G, Salvatori R, Brunetti L. Effects of growth hormone-releasing hormone gene targeted ablation on ghrelin-induced feeding. Growth Horm IGF Res 2017; 37:40-46. [PMID: 29121520 DOI: 10.1016/j.ghir.2017.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 12/30/2022]
Abstract
Impairment of growth hormone (GH) signaling has been associated with increased feeding and adiposity. The gastric hormone ghrelin, in addition to its GH-secretagogue effects, stimulates food intake after both central and peripheral administration. In the present study we further investigated the feeding regulatory role of the ghrelin-GH axis in a mouse model of isolated GH deficiency due to targeted ablation of the GH-releasing hormone (GHRH) gene [GHRH knockout (GHRHKO)]. We evaluated the effects of intracerebroventricular ghrelin administration on feeding behavior, related hypothalamic neuropeptides and neurotransmitters, and serum ghrelin levels in mice homozygous for GHRHKO allele (-/-) and heterozygous (+/-) control animals. Vehicle-treated GHRHKO mice showed increased food intake compared to heterozygotes, associated with increased circulating ghrelin levels. Moreover, -/- mice showed elevated hypothalamic levels of neuropeptide Y (NPY), agouti-related peptide (AgRP) mRNAs and norepinephrine (NE) and decreased corticotropin-releasing hormone (CRH) mRNA levels. Ghrelin treatment significantly augmented food intake in both genotypes, but the relative increase compared to vehicle-treated animals was higher in -/- than +/- mice. In the hypothalamus, ghrelin increased AgRP and decreased CRH gene expression only in heterozygous mice, while it induced a significant reduction in proopiomelanocortin (POMC) mRNA levels in -/- mice. Ghrelin treatment also decreased hypothalamic serotonin (5-hydroxytriptamine, 5-HT) and dopamine (DA) levels in both genotypes. Additionally, we observed increased DA metabolism induced by ghrelin in both genotypes. In conclusion, dysregulation of the ghrelin-GHRH-GH axis in GHRHKO mice could lead to increased feeding secondary to elevated circulating levels of ghrelin, and the obesogenic phenotype is likely mediated by elevated NPY and AgRP, and decreased CRH gene expression in the hypothalamus.
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Affiliation(s)
- Lucia Recinella
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
| | - Sheila Leone
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
| | | | | | - Rugia Shohreh
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
| | - Chiara Di Nisio
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
| | - Michele Vacca
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
| | - Giustino Orlando
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy.
| | - Roberto Salvatori
- Division of Endocrinology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Luigi Brunetti
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
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Effects of ghrelin on activation of Akt1 and ERK1/2 pathways during in vitro maturation of bovine oocytes. ZYGOTE 2017; 25:183-189. [PMID: 28264754 DOI: 10.1017/s096719941700003x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus-oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml-1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM). At 18 and 24 h no difference existed in the proportion of matured oocytes in the ghrelin-treated group, while in the control group more (P < 0.05) matured oocyte were found at 24 h. Oocyte maturation for 24 h in the presence of ghrelin resulted in substantially reduced (P < 0.05) blastocyst yield(16.3%) in comparison with that obtained after 18 h (30.0%) or to both control groups (29.3% and 26.9%, for 18 and 24 h in maturation, respectively). Ghrelin-treated oocytes expressed lower Akt1 phosphorylation rate at the 10th hour of IVM, and higher ERK1/2 at the 6th and 10th hours of IVM compared with controls. In cumulus cells, at the 18th and 24th hours of IVM Akt1 phosphorylation rate was higher in ghrelin-treated oocytes. Our results imply that ghrelin acts in a different time-dependent manner on bovine oocytes and cumulus cells modulating Akt1 and ERK1/2 phosphorylation, which brings about acceleration of the oocyte maturation process.
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From Belly to Brain: Targeting the Ghrelin Receptor in Appetite and Food Intake Regulation. Int J Mol Sci 2017; 18:ijms18020273. [PMID: 28134808 PMCID: PMC5343809 DOI: 10.3390/ijms18020273] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/19/2017] [Indexed: 12/20/2022] Open
Abstract
Ghrelin is the only known peripherally-derived orexigenic hormone, increasing appetite and subsequent food intake. The ghrelinergic system has therefore received considerable attention as a therapeutic target to reduce appetite in obesity as well as to stimulate food intake in conditions of anorexia, malnutrition and cachexia. As the therapeutic potential of targeting this hormone becomes clearer, it is apparent that its pleiotropic actions span both the central nervous system and peripheral organs. Despite a wealth of research, a therapeutic compound specifically targeting the ghrelin system for appetite modulation remains elusive although some promising effects on metabolic function are emerging. This is due to many factors, ranging from the complexity of the ghrelin receptor (Growth Hormone Secretagogue Receptor, GHSR-1a) internalisation and heterodimerization, to biased ligand interactions and compensatory neuroendocrine outputs. Not least is the ubiquitous expression of the GHSR-1a, which makes it impossible to modulate centrally-mediated appetite regulation without encroaching on the various peripheral functions attributable to ghrelin. It is becoming clear that ghrelin’s central signalling is critical for its effects on appetite, body weight regulation and incentive salience of food. Improving the ability of ghrelin ligands to penetrate the blood brain barrier would enhance central delivery to GHSR-1a expressing brain regions, particularly within the mesolimbic reward circuitry.
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Verburg-van Kemenade BML, Cohen N, Chadzinska M. Neuroendocrine-immune interaction: Evolutionarily conserved mechanisms that maintain allostasis in an ever-changing environment. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 66:2-23. [PMID: 27296493 DOI: 10.1016/j.dci.2016.05.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 05/23/2016] [Accepted: 05/23/2016] [Indexed: 05/02/2023]
Abstract
It has now become accepted that the immune system and neuroendocrine system form an integrated part of our physiology. Immunological defense mechanisms act in concert with physiological processes like growth and reproduction, energy intake and metabolism, as well as neuronal development. Not only are psychological and environmental stressors communicated to the immune system, but also, vice versa, the immune response and adaptation to a current pathogen challenge are communicated to the entire body, including the brain, to evoke adaptive responses (e.g., fever, sickness behavior) that ensure allocation of energy to fight the pathogen. This phenomenon is evolutionarily conserved. Hence it is both interesting and important to consider the evolutionary history of this bi-directional neuroendocrine-immune communication to reveal phylogenetically ancient or relatively recently acquired mechanisms. Indeed, such considerations have already disclosed an extensive "common vocabulary" of information pathways as well as molecules and their receptors used by both the neuroendocrine and immune systems. This review focuses on the principal mechanisms of bi-directional communication and the evidence for evolutionary conservation of the important physiological pathways involved.
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Affiliation(s)
- B M Lidy Verburg-van Kemenade
- Cell Biology and Immunology Group, Dept. of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
| | - Nicholas Cohen
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14620, USA
| | - Magdalena Chadzinska
- Department of Evolutionary Immunology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, PL30-387 Krakow, Poland
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Ghrelin suppresses the GnRH-induced preovulatory gonadotropin surge in dairy heifers. Theriogenology 2016; 86:1615-1621. [DOI: 10.1016/j.theriogenology.2016.05.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 05/19/2016] [Accepted: 05/19/2016] [Indexed: 12/16/2022]
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12
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Lee JH, Kim TJ, Kim JW, Yoon JS, Kim HS, Lee KM. The Anti-apoptotic Effect of Ghrelin on Restraint Stress-Induced Thymus Atrophy in Mice. Immune Netw 2016; 16:242-8. [PMID: 27574503 PMCID: PMC5002450 DOI: 10.4110/in.2016.16.4.242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 07/29/2016] [Accepted: 08/04/2016] [Indexed: 12/22/2022] Open
Abstract
Thymic atrophy is a complication that results from exposure to many environmental stressors, disease treatments, and microbial challenges. Such acute stress-associated thymic loss can have a dramatic impact on the host's ability to replenish the necessary naïve T cell output to reconstitute the peripheral T cell numbers and repertoire to respond to new antigenic challenges. We have previously reported that treatment with the orexigenic hormone ghrelin results in an increase in the number and proliferation of thymocytes after dexamethasone challenge, suggesting a role for ghrelin in restraint stress-induced thymic involution and cell apoptosis and its potential use as a thymostimulatory agent. In an effort to understand how ghrelin suppresses thymic T cell apoptosis, we have examined the various signaling pathways induced by receptor-specific ghrelin stimulation using a restraint stress mouse model. In this model, stress-induced apoptosis in thymocytes was effectively blocked by ghrelin. Western blot analysis demonstrated that ghrelin prevents the cleavage of pro-apoptotic proteins such as Bim, Caspase-3, and PARP. In addition, ghrelin stimulation activates the Akt and Mitogen-activated protein kinases (MAPK) signaling pathways in a time/dose-dependent manner. Moreover, we also revealed the involvement of the FoxO3a pathway in the phosphorylation of Akt and ERK1/2. Together, these findings suggest that ghrelin inhibits apoptosis by modulating the stress-induced apoptotic signal pathway in the restraint-induced thymic apoptosis.
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Affiliation(s)
- Jun Ho Lee
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, Korea University, Seoul 02841, Korea
| | - Tae-Jin Kim
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, Korea University, Seoul 02841, Korea
| | - Jie Wan Kim
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam 13524, Korea
| | - Jeong Seon Yoon
- Department of Anatomy, School of Medicine, Ajou University, Suwon 16499, Korea
| | - Hyuk Soon Kim
- Department of Immunology, School of Medicine, Konkuk University, Chungju 27478, Korea
| | - Kyung-Mi Lee
- Global Research Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, Korea University, Seoul 02841, Korea
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13
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Carrasco F, Basfi-Fer K, Rojas P, Valencia A, Csendes A, Codoceo J, Inostroza J, Ruz M. Changes in bone mineral density after sleeve gastrectomy or gastric bypass: relationships with variations in vitamin D, ghrelin, and adiponectin levels. Obes Surg 2015; 24:877-84. [PMID: 24435517 DOI: 10.1007/s11695-014-1179-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND A major long-term concern after gastric bypass (GBP) is the risk of osteoporosis; however, little is known about this complication in patients undergoing sleeve gastrectomy (SG). OBJECTIVE To evaluate changes in bone mineral density (BMD) after GBP and SG, and its relationship with changes in vitamin D, parathyroid hormone (PTH), ghrelin, and adiponectin. METHODS Twenty-three women undergoing GBP (BMI 42.0 ± 4.2 kg/m2; 37.3 ± 8.1 years) and 20 undergoing SG (BMI 37.3 ± 3.2 kg/m2; 34.2 ± 10.2 years) were studied before and 6 and 12 months after surgery. BMD was measured by dual-energy X-ray absorptiometry. Plasma PTH, 25-hydroxyvitamin D (25-OHD), ghrelin, and adiponectin concentrations were determined. Food as well as calcium and vitamin D supplement intake was recorded. RESULTS Excess weight loss (mean ± SE), adjusted by baseline excess weight, was 79.1±3.8% and 74.9 ± 4.1% 1 year after GBP and SG, respectively (p = 0.481). Significant reduction in BMD for total body (TB), lumbar spine (LS), and femoral neck (FN) was observed after GBP. In the SG group, reduction in BMD was significant only for TB. Adjusted by baseline BMD, the difference between change in BMD for GBP vs. SG was not significant for TB, LS, or FN. Percent reduction in ghrelin concentration was a main factor related to total BMD loss (GBP group) and LS BMD loss (GBP and SG groups). CONCLUSIONS One year after gastric bypass, bone mineral density was significantly affected, mainly at the femoral neck. Decreases in bone mineral density were more dramatic among patients who had greater baseline BMD and greater reduction in ghrelin concentrations.
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Affiliation(s)
- Fernando Carrasco
- Department of Nutrition, Faculty of Medicine, University of Chile, Independencia 1027, 8380453, Santiago, Chile
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14
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Koyuturk M, Sacan O, Karabulut S, Turk N, Bolkent S, Yanardag R, Bolkent S. The role of ghrelin on apoptosis, cell proliferation and oxidant-antioxidant system in the liver of neonatal diabetic rats. Cell Biol Int 2015; 39:834-41. [PMID: 25789445 DOI: 10.1002/cbin.10464] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/18/2015] [Indexed: 01/09/2023]
Abstract
Ghrelin is a multifunctional peptide hormone which stimulates appetite and regulates glucose metabolism and adipogenesis. The purpose of this study was to investigate whether ghrelin has protective effects in the liver of streptozocin (STZ) diabetic rats or not. Wistar-type neonatal rats were divided into four groups: I. Controls, II. Ghrelin administrated controls, III. STZ-diabetic rats, and IV. Ghrelin administrated diabetic rats. On the second day after birth, 100 mg/kg STZ was administered intraperitoneally in a single dose to induce diabetes in rats. 100 µg/kg/day ghrelin was administrated to rats subcutaneously for 4 weeks. Ghrelin administration improved histopathologic changes in STZ-diabetic liver. Obestatin immunoreactivity has been shown in livers of neonatal rats. The immunoreactivity of obestatin increased in diabetic rats and a decline was observed in ghrelin administrated diabetic rats. Caspase 8 and 3 immunoreactivities increased in diabetic rats; however, ghrelin administration differently affected caspases 8 and 3 immunoreactivities. Proliferating cell nuclear antigen immunoreactivities decreased in diabetic rats and in ghrelin administrated diabetic rats. Serum alanine (P < 0.05) and aspartate transaminase (P < 0.0001) and serum alkaline phosphatase (P < 0.0001) activities were decreased in ghrelin administrated diabetic rats compared to the diabetic rats. Gamma glutamyl transferase activity (P < 0.001) decreased in ghrelin administrated diabetic rats compared to the diabetic rats. The response of antioxidants including glutathione levels, catalase and superoxide dismutase activities were altered in ghrelin administrated diabetic rats. Our findings indicate that ghrelin administration affects hepatic functions in neonatal diabetic rats and might be considered as a therapeutic agent.
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Affiliation(s)
- Meral Koyuturk
- Department of Histology and Embryology, Faculty of Cerrahpasa Medicine, Istanbul University, Cerrahpasa, Turkey
| | - Ozlem Sacan
- Department of Chemistry, Faculty of Engineering, Istanbul University, Avcilar, Turkey
| | - Sezin Karabulut
- Department of Medical Biology, Faculty of Cerrahpasa Medicine, Istanbul University, Cerrahpasa, Turkey
| | - Neslihan Turk
- Department of Medical Biology, Faculty of Cerrahpasa Medicine, Istanbul University, Cerrahpasa, Turkey
| | - Sehnaz Bolkent
- Department of Biology, Faculty of Science, Istanbul University, Vezneciler, Istanbul, Turkey
| | - Refiye Yanardag
- Department of Chemistry, Faculty of Engineering, Istanbul University, Avcilar, Turkey
| | - Sema Bolkent
- Department of Medical Biology, Faculty of Cerrahpasa Medicine, Istanbul University, Cerrahpasa, Turkey
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15
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Lee JH, Patel K, Tae HJ, Lustig A, Kim JW, Mattson MP, Taub DD. Ghrelin augments murine T-cell proliferation by activation of the phosphatidylinositol-3-kinase, extracellular signal-regulated kinase and protein kinase C signaling pathways. FEBS Lett 2014; 588:4708-19. [PMID: 25447526 DOI: 10.1016/j.febslet.2014.10.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/21/2014] [Accepted: 10/27/2014] [Indexed: 12/13/2022]
Abstract
Thymic atrophy occurs during normal aging, and is accelerated by exposure to chronic stressors that elevate glucocorticoid levels and impair the naïve T cell output. The orexigenic hormone ghrelin was recently shown to attenuate age-associated thymic atrophy. Here, we report that ghrelin enhances the proliferation of murine CD4+ primary T cells and a CD4+ T-cell line. Ghrelin induced activation of the ERK1/2 and Akt signaling pathways, via upstream activation of phosphatidylinositol-3-kinase and protein kinase C, to enhance T-cell proliferation. Moreover, ghrelin induced expression of the cell cycle proteins cyclin D1, cyclin E, cyclin-dependent kinase 2 (CDK2) and retinoblastoma phosphorylation. Finally, ghrelin activated the above-mentioned signaling pathways and stimulated thymocyte proliferation in young and older mice in vivo.
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Affiliation(s)
- Jun Ho Lee
- Laboratory of Molecular Biology and Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States; Department of Biochemistry and Division of Brain Korea 21 Plus Program for Biomedical Science, Korea University College of Medicine, Seoul 136-701, Republic of Korea
| | - Kalpesh Patel
- Laboratory of Molecular Biology and Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States
| | - Hyun Jin Tae
- Laboratory of Cardiovascular Science, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States
| | - Ana Lustig
- Laboratory of Molecular Biology and Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States
| | - Jie Wan Kim
- Laboratory of Molecular Biology and Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States.
| | - Dennis D Taub
- Laboratory of Molecular Biology and Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, United States; Center of Translational Studies, Medical Services, Veteran Affairs Medical Center, Washington, DC 20422, United States.
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16
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Hara M, Nishi Y, Yamashita Y, Hirata R, Takahashi S, Nagamitsu SI, Hosoda H, Kangawa K, Kojima M, Matsuishi T. Relation between circulating levels of GH, IGF-1, ghrelin and somatic growth in Rett syndrome. Brain Dev 2014; 36:794-800. [PMID: 24377437 DOI: 10.1016/j.braindev.2013.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 11/06/2013] [Accepted: 11/18/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND Most cases of Rett syndrome (RTT) are caused by mutations in methyl CpG binding protein 2 (MECP2), and individuals with RTT have somatic growth failure, growth arrest of brain, epilepsy, and intellectual disability (ID). Ghrelin is a peptide hormone which stimulates growth hormone (GH) secretion from the pituitary gland. Ghrelin and GH regulate insulin-like growth factor-1 (IGF-1) synthesis, and this GH/IGF-1 axis is an endocrine axis involved in energy and sleep homeostasis and plays crucial roles in somatic and brain growth. This study aimed to determine whether circulating ghrelin, GH and IGF-1 reflect somatic and brain growth in RTT patients. METHODS We examined anthropometric data and circulating ghrelin, GH, and IGF-1 in 22 female RTT patients with epilepsy and ID (RTT-Ep/ID) and 14 age-matched females with epilepsy and ID (non-RTT-Ep/ID). RESULTS Body mass index (BMI) and height/length were significantly lower in RTT-Ep/ID than in non-RTT-Ep/ID in patients less than 20 years old. Plasma ghrelin in RTT-Ep/ID patients showed a significant inverse correlation with weight but had no significant correlations with BMI or height. Head circumference in both groups showed a significant positive correlation with circulating ghrelin and a significant negative correlation with circulating IGF-1. The ratio of octanoyl-ghrelin to total-ghrelin (O/T-ratio) is used as an indicator to estimate the biological activity of ghrelin. Among pre-adolescents, O/T-ratios were significantly higher in the RTT-Ep/ID group than in the non-RTT-Ep/ID group (P < 0.05). CONCLUSIONS Timing of growth-spurts differed between the RTT-Ep/ID and non-RTT-Ep/ID groups, possibly due to a common (but yet unknown) mechanism of growth failure. Ghrelin/GH/IGF-1 axis function was aberrant in both the RTT-Ep/ID and non-RTT-Ep/ID groups. The initial clinical course of Rett syndrome affects the development of the sleep-wake cycle and locomotion in early infancy, both of which may be based on the dysfunction of the aminergic neurons modulated by ghrelin/GH/IGF-1 axis. Further study with a larger sample size should help clarify the precise mechanisms controlling the somatic growth and hormonal features in Rett syndrome.
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Affiliation(s)
- Munetsugu Hara
- Department of Neonatology, Medical Center for Maternal and Child Health, St. Mary's Hospital, Kurume, Fukuoka 830-8543, Japan
| | - Yoshihiro Nishi
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Yushiro Yamashita
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Rumiko Hirata
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Satoru Takahashi
- Department of Pediatrics, Asahikawa Medical University, Asahikawa, Hokkaido 078-8510, Japan
| | - Shin-Ichiro Nagamitsu
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Hiroshi Hosoda
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Masayasu Kojima
- Institute of Life Science, Kurume University, Hyakunenkohen, Kurume, Fukuoka 839-0864, Japan
| | - Toyojiro Matsuishi
- Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan.
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17
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Preclinical gastrointestinal prokinetic efficacy and endocrine effects of the ghrelin mimetic RM-131. Life Sci 2014; 109:20-9. [PMID: 24931905 DOI: 10.1016/j.lfs.2014.06.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/28/2014] [Accepted: 06/03/2014] [Indexed: 12/11/2022]
Abstract
AIMS The 28 amino acid hormone ghrelin, the natural ligand for the growth hormone secretagogue, or ghrelin receptor (GHR), has diverse physiological functions, including a possible role as a gastrointestinal prokinetic. The synthetic ghrelin mimetic RM-131 is in Phase II clinical trials for treatment of diabetic gastroparesis and other gastrointestinal (GI) disorders. We aimed to determine the relative potency of RM-131, when compared to other GI ghrelin mimetics, to predict efficacy and determine the role of RM-131 in models of inflammatory bowel disease. MAIN METHODS We evaluated and compared ghrelin, RM-131 and other synthetic ghrelin mimetics for their prokinetic potency in models of gastrointestinal disorders in the rat and we evaluated the endocrine (rats and dogs) and anti-inflammatory effects (mice) of the ghrelin mimetic RM-131. KEY FINDINGS The pentapeptide RM-131 increased gastric emptying in rodent models of ileus. RM-131 is about 100-fold more potent than human ghrelin and is 600 to 1800-fold more potent, when compared to several investigational ghrelin mimetics tested in clinical trials. RM-131 has anti-inflammatory effects and significantly increases survival and reduces macroscopic markers of tissue damage in a TNBS model of inflammatory bowel disease. RM-131 treatment shows a transient increase in growth hormone levels in Beagle dogs and rats, returning to baseline upon chronic treatment. Significant effects on glucose and insulin are not observed in chronic studies. SIGNIFICANCE RM-131's potency, efficacy and endocrine profile, are promising attributes for the treatment of diverse functional gastrointestinal disorders in humans.
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18
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Giordano C, Marchiò M, Timofeeva E, Biagini G. Neuroactive peptides as putative mediators of antiepileptic ketogenic diets. Front Neurol 2014; 5:63. [PMID: 24808888 PMCID: PMC4010764 DOI: 10.3389/fneur.2014.00063] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/14/2014] [Indexed: 12/14/2022] Open
Abstract
Various ketogenic diet (KD) therapies, including classic KD, medium chain triglyceride administration, low glycemic index treatment, and a modified Atkins diet, have been suggested as useful in patients affected by pharmacoresistant epilepsy. A common goal of these approaches is to achieve an adequate decrease in the plasma glucose level combined with ketogenesis, in order to mimic the metabolic state of fasting. Although several metabolic hypotheses have been advanced to explain the anticonvulsant effect of KDs, including changes in the plasma levels of ketone bodies, polyunsaturated fatty acids, and brain pH, direct modulation of neurotransmitter release, especially purinergic (i.e., adenosine) and γ-aminobutyric acidergic neurotransmission, was also postulated. Neuropeptides and peptide hormones are potent modulators of synaptic activity, and their levels are regulated by metabolic states. This is the case for neuroactive peptides such as neuropeptide Y, galanin, cholecystokinin, and peptide hormones such as leptin, adiponectin, and growth hormone-releasing peptides (GHRPs). In particular, the GHRP ghrelin and its related peptide des-acyl ghrelin are well-known controllers of energy homeostasis, food intake, and lipid metabolism. Notably, ghrelin has also been shown to regulate the neuronal excitability and epileptic activation of neuronal networks. Several lines of evidence suggest that GHRPs are upregulated in response to starvation and, particularly, in patients affected by anorexia and cachexia, all conditions in which also ketone bodies are upregulated. Moreover, starvation and anorexia nervosa are accompanied by changes in other peptide hormones such as adiponectin, which has received less attention. Adipocytokines such as adiponectin have also been involved in modulating epileptic activity. Thus, neuroactive peptides whose plasma levels and activity change in the presence of ketogenesis might be potential candidates for elucidating the neurohormonal mechanisms involved in the beneficial effects of KDs. In this review, we summarize the current evidence for altered regulation of the synthesis of neuropeptides and peripheral hormones in response to KDs, and we try to define a possible role for specific neuroactive peptides in mediating the antiepileptic properties of diet-induced ketogenesis.
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Affiliation(s)
- Carmela Giordano
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Maddalena Marchiò
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Neuropediatric Unit, Department of Medical and Surgical Sciences for Children and Adults, Policlinico Hospital, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neurosciences, NOCSAE Hospital, Modena, Italy
| | - Elena Timofeeva
- Département Psychiatrie et Neurosciences, Faculté de Médecine, Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neurosciences, NOCSAE Hospital, Modena, Italy
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19
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Human ghrelin decreases pituitary response to GnRH in superovulated ewes. Theriogenology 2013; 80:262-8. [PMID: 23664792 DOI: 10.1016/j.theriogenology.2013.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/07/2013] [Accepted: 04/08/2013] [Indexed: 12/16/2022]
Abstract
In addition to its metabolic role, ghrelin has been found to suppress luteinizing hormone secretion in many species acting mainly at the hypothalamic level. The objectives of the present study were to test the hypothesis that besides its effects on the hypothalamic level, ghrelin exerts a direct action on the pituitary. Twelve cycling ewes were synchronized, using progestagen intravaginal sponges and superovulated using eCG. At the time of sponge withdrawal, animals were allocated into two groups, ghrelin-treated (Gh) and control. Two days after the sponge removal, GnRH was given to synchronize ovulations. Simultaneously with GnRH treatment, animals of the Gh group received the first of four treatments of acylated human ghrelin at a dose of 6 μg/kg body weight iv; three additional treatments of ghrelin iv were given every 15 minutes thereafter. Control animals received saline iv. Blood samples were collected before challenge (-30 and 0 minutes) and at 30, 60, 75, 90, 105, 120, 135, 150, and 180 minutes after GnRH treatment, and were analyzed for LH, FSH, estradiol, progesterone, insulin, and insulin-like growth factor-I concentrations. Ghrelin treatment attenuated GnRH-induced a preovulatory surge of both gonadotrophins, with the effect being greater for LH. No difference was detected for insulin, estradiol, and progesterone concentrations, and insulin-like growth factor-I levels were increased in the Gh group. Our results imply that in sheep, ghrelin conducts specific regulatory effects on the GnRH/LH axis, and provide for the first time strong evidence that besides its central action, ghrelin might regulate gonadotrophin release acting at the pituitary level.
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20
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Raghay K, Gallego R, Scoazec JY, Garcia-Caballero T, Morel G. Different ghrelin localisation in adult human and rat endocrine pancreas. Cell Tissue Res 2013; 352:487-94. [PMID: 23584608 DOI: 10.1007/s00441-013-1593-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/15/2013] [Indexed: 12/25/2022]
Abstract
Ghrelin is an endocrine peptide that has been identified in gastric oxyntic glands and that induces growth hormone secretion in the pituitary gland. This growth hormone secretagogue is expressed in many tissues such as stomach, pituitary gland, thyroid, testis, placenta and pancreas. Initial studies of ghrelin focused on its role as a circulating orexigenic signal. However, ghrelin has also been found to be involved in the modulation of glucose homeostasis. Although a number of studies have reported ghrelin expression in developing pancreas, the location of ghrelin-immunoreactive cells in adult pancreas (epsilon cells) remains controversial. In this study, we have analysed the distribution of pancreatic epsilon cells in adult human and rat islets by immunohistochemistry and in situ hybridisation. In humans, our immunohistochemical analysis has shown that ghrelin is expressed in glucagon-secreting cells, whereas in rats, it is present in insulin-secreting cells. Similar observations have been revealed by in situ hybridisation.
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Affiliation(s)
- Kawtar Raghay
- Inserm U 1052/CNRS UMR 5286, Claude Bernard University, Lyon, France
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21
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Chanclón B, Luque RM, Córdoba-Chacón J, Gahete MD, Pozo-Salas AI, Castaño JP, Gracia-Navarro F, Martínez-Fuentes AJ. Role of endogenous cortistatin in the regulation of ghrelin system expression at pancreatic level under normal and obese conditions. PLoS One 2013; 8:e57834. [PMID: 23469081 PMCID: PMC3585174 DOI: 10.1371/journal.pone.0057834] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/26/2013] [Indexed: 12/11/2022] Open
Abstract
Ghrelin-system components [native ghrelin, In1-ghrelin, Ghrelin-O-acyltransferase enzyme (GOAT) and receptors (GHS-Rs)] are expressed in a wide variety of tissues, including the pancreas, where they exert different biological actions including regulation of neuroendocrine secretions, food intake and pancreatic function. The expression of ghrelin system is regulated by metabolic conditions (fasting/obesity) and is associated with the progression of obesity and insulin resistance. Cortistatin (CORT), a neuropeptide able to activate GHS-R, has emerged as an additional link in gut-brain interplay. Indeed, we recently reported that male CORT deficient mice (cort−/−) are insulin-resistant and present a clear dysregulation in the stomach ghrelin-system. The present work was focused at analyzing the expression pattern of ghrelin-system components at pancreas level in cort−/− mice and their control littermates (cort +/+) under low- or high-fat diet. Our data reveal that all the ghrelin-system components are expressed at the mouse pancreatic level, where, interestingly, In1-ghrelin was expressed at higher levels than native-ghrelin. Thus, GOAT mRNA levels were significantly lower in cort−/− mice compared with controls while native ghrelin, In1-ghrelin and GHS-R transcript levels remained unaltered under normal metabolic conditions. Moreover, under obese condition, a significant increase in pancreatic expression of native-ghrelin, In1-ghrelin and GHS-R was observed in obese cort+/+ but not in cort−/− mice. Interestingly, insulin expression and release was elevated in obese cort+/+, while these changes were not observed in obese cort−/− mice. Altogether, our results indicate that the ghrelin-system expression is clearly regulated in the pancreas of cort+/+ and cort −/− under normal and/or obesity conditions suggesting that this system may play relevant roles in the endocrine pancreas. Most importantly, our data demonstrate, for the first time, that endogenous CORT is essential for the obesity-induced changes in insulin expression/secretion observed in mice, suggesting that CORT is a key regulatory component of the pancreatic function.
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Affiliation(s)
- Belén Chanclón
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Raúl M. Luque
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - José Córdoba-Chacón
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Manuel D. Gahete
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Ana I. Pozo-Salas
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Justo P. Castaño
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Francisco Gracia-Navarro
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Antonio J. Martínez-Fuentes
- Department of Cell Biology, Physiology and Immunology, University of Cordoba and Reina Sofia University Hospital, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
- * E-mail:
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22
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Hart AW, Mella S, Mendrychowski J, van Heyningen V, Kleinjan DA. The developmental regulator Pax6 is essential for maintenance of islet cell function in the adult mouse pancreas. PLoS One 2013; 8:e54173. [PMID: 23326594 PMCID: PMC3543312 DOI: 10.1371/journal.pone.0054173] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/07/2012] [Indexed: 11/18/2022] Open
Abstract
The transcription factor Pax6 is a developmental regulator with a crucial role in development of the eye, brain, and olfactory system. Pax6 is also required for correct development of the endocrine pancreas and specification of hormone producing endocrine cell types. Glucagon-producing cells are almost completely lost in Pax6-null embryos, and insulin-expressing beta and somatostatin-expressing delta cells are reduced. While the developmental role of Pax6 is well-established, investigation of a further role for Pax6 in the maintenance of adult pancreatic function is normally precluded due to neonatal lethality of Pax6-null mice. Here a tamoxifen-inducible ubiquitous Cre transgene was used to inactivate Pax6 at 6 months of age in a conditional mouse model to assess the effect of losing Pax6 function in adulthood. The effect on glucose homeostasis and the expression of key islet cell markers was measured. Homozygous Pax6 deletion mice, but not controls, presented with all the symptoms of classical diabetes leading to severe weight loss requiring termination of the experiment five weeks after first tamoxifen administration. Immunohistochemical analysis of the pancreata revealed almost complete loss of Pax6 and much reduced expression of insulin, glucagon, and somatostatin. Several other markers of islet cell function were also affected. Notably, strong upregulation in the number of ghrelin-expressing endocrine cells was observed. These findings demonstrate that Pax6 is essential for adult maintenance of glucose homeostasis and function of the endocrine pancreas.
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Affiliation(s)
- Alan W. Hart
- Medical Research Council Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, United Kingdom
| | - Sebastien Mella
- Medical Research Council Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, United Kingdom
| | - Jacek Mendrychowski
- Medical Research Council Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, United Kingdom
| | - Veronica van Heyningen
- Medical Research Council Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, United Kingdom
| | - Dirk A. Kleinjan
- Medical Research Council Human Genetics Unit at the Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Méquinion M, Langlet F, Zgheib S, Dickson S, Dehouck B, Chauveau C, Viltart O. Ghrelin: central and peripheral implications in anorexia nervosa. Front Endocrinol (Lausanne) 2013; 4:15. [PMID: 23549309 PMCID: PMC3581855 DOI: 10.3389/fendo.2013.00015] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/01/2013] [Indexed: 11/15/2022] Open
Abstract
Increasing clinical and therapeutic interest in the neurobiology of eating disorders reflects their dramatic impact on health. Chronic food restriction resulting in severe weight loss is a major symptom described in restrictive anorexia nervosa (AN) patients, and they also suffer from metabolic disturbances, infertility, osteopenia, and osteoporosis. Restrictive AN, mostly observed in young women, is the third largest cause of chronic illness in teenagers of industrialized countries. From a neurobiological perspective, AN-linked behaviors can be considered an adaptation that permits the endurance of reduced energy supply, involving central and/or peripheral reprograming. The severe weight loss observed in AN patients is accompanied by significant changes in hormones involved in energy balance, feeding behavior, and bone formation, all of which can be replicated in animals models. Increasing evidence suggests that AN could be an addictive behavior disorder, potentially linking defects in the reward mechanism with suppressed food intake, heightened physical activity, and mood disorder. Surprisingly, the plasma levels of ghrelin, an orexigenic hormone that drives food-motivated behavior, are increased. This increase in plasma ghrelin levels seems paradoxical in light of the restrained eating adopted by AN patients, and may rather result from an adaptation to the disease. The aim of this review is to describe the role played by ghrelin in AN focusing on its central vs. peripheral actions. In AN patients and in rodent AN models, chronic food restriction induces profound alterations in the « ghrelin » signaling that leads to the development of inappropriate behaviors like hyperactivity or addiction to food starvation and therefore a greater depletion in energy reserves. The question of a transient insensitivity to ghrelin and/or a potential metabolic reprograming is discussed in regard of new clinical treatments currently investigated.
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Affiliation(s)
- Mathieu Méquinion
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
| | - Fanny Langlet
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
| | - Sara Zgheib
- Pathophysiology of inflammatory of bone diseases, Université Lille Nord de France-ULCO – Lille 2Boulogne sur Mer, France
| | - Suzanne Dickson
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
- Department of Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Bénédicte Dehouck
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
- Université Lille Nord de France – Université d’ArtoisLiévin, France
| | - Christophe Chauveau
- Pathophysiology of inflammatory of bone diseases, Université Lille Nord de France-ULCO – Lille 2Boulogne sur Mer, France
| | - Odile Viltart
- UMR INSERM 837, Development and Plasticity of Postnatal BrainLille, France
- Université Lille Nord de France-USTL (Lille 1)Villeneuve d’Ascq, France
- *Correspondence: Odile Viltart, Development and Plasticity of the Postnatal Brain, Team 2, Jean-Pierre Aubert Research Center, UMR INSERM 837, Bât Biserte, 1 place de Verdun, 59,045 Lille cedex, France. e-mail:
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Currie PJ, Coiro CD, Duenas R, Guss JL, Mirza A, Tal N. Urocortin I inhibits the effects of ghrelin and neuropeptide Y on feeding and energy substrate utilization. Brain Res 2012; 1385:127-34. [PMID: 21303672 DOI: 10.1016/j.brainres.2011.01.114] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/29/2011] [Accepted: 01/31/2011] [Indexed: 02/02/2023]
Abstract
The corticotropin releasing hormone-related ligand, urocortin-I (UcnI), suppresses food intake when injected into multiple hypothalamic and extrahypothalamic areas. UcnI also alters energy substrate utilization, specifically via enhanced fat oxidation as reflected in reductions in respiratory quotient (RQ). In the present study we compared the feeding and metabolic effects of ghrelin and NPY following pretreatment with UcnI. Direct PVN injections of NPY (50 pmol) and ghrelin (50 pmol) were orexigenic while UcnI (10-40 pmol) reliably suppressed food intake. Both ghrelin and NPY increased RQ, indicating enhanced utilization of carbohydrates and the preservation of fat stores. UcnI alone suppressed RQ responses. PVN UcnI attenuated the effects of both ghrelin and NPY on food intake and energy substrate utilization. While ghrelin (5 pmol) potentiated the effect of NPY (25 pmol) on RQ and food intake, these responses were inhibited by pretreatment with UcnI (10 pmol). In conclusion, PVN NPY and ghrelin stimulate eating and promote carbohydrate oxidation while inhibiting fat utilization. These effects are blocked by UcnI which alone suppresses appetite and promotes fat oxidation. Overall these findings are consistent with a possible interactive role of PVN NPY, ghrelin and urocortin in the modulation of appetite and energy metabolism.
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Affiliation(s)
- Paul J Currie
- Department of Psychology, Reed College, 3203 SE Woodstock Blvd, Portland, OR 97202, USA.
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Beléen C, Martínez-Fuentes AJ, Gracia-Navarro F. Role of SST, CORT and ghrelin and its receptors at the endocrine pancreas. Front Endocrinol (Lausanne) 2012; 3:114. [PMID: 23162532 PMCID: PMC3444847 DOI: 10.3389/fendo.2012.00114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 09/03/2012] [Indexed: 12/21/2022] Open
Abstract
Somatostatin (SST), cortistatin (CORT), and its receptors (sst1-5), and ghrelin and its receptors (GHS-R) are two highly interrelated neuropeptide systems with a broad range of overlapping biological actions at central, cardiovascular, and immune levels among others. Besides their potent regulatory role on GH release, its endocrine actions are highlighted by SST/CORT and ghrelin influence on insulin secretion, glucose homeostasis, and insulin resistance. Interestingly, most components of these systems are expressed at the endocrine pancreas and are actively involved in the modulation of pancreatic islet function and, consequently influence glucose homeostasis. In addition, some of them also participate in islet survival and regeneration. Furthermore, under severe metabolic condition as well as in endocrine pathologies, their expression profile is severely deregulated. These findings suggest that SST/CORT and ghrelin systems could play a relevant role in pancreatic function under metabolic and endocrine pathologies. Accordingly, these systems have been therapeutically targeted for the prevention or amelioration of certain metabolic conditions (obesity) as well as for tumor growth inhibition and/or hormonal regulation in endocrine pathologies (neuroendocrine tumors). This review focuses on the interrelationship between SST/CORT and ghrelin systems and their role in severe metabolic conditions and some endocrine disorders.
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Affiliation(s)
- Chanclón Beléen
- Department of Cell Biology, Physiology and Immunology, University of CórdobaCórdoba, Spain
- Instituto Maimónides de Investigación Biomédica de CórdobaCórdoba, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y NutriciónCórdoba, Spain
| | - Antonio J. Martínez-Fuentes
- Department of Cell Biology, Physiology and Immunology, University of CórdobaCórdoba, Spain
- Instituto Maimónides de Investigación Biomédica de CórdobaCórdoba, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y NutriciónCórdoba, Spain
| | - Francisco Gracia-Navarro
- Department of Cell Biology, Physiology and Immunology, University of CórdobaCórdoba, Spain
- Instituto Maimónides de Investigación Biomédica de CórdobaCórdoba, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y NutriciónCórdoba, Spain
- *Correspondence: Francisco Gracia-Navarro, Department of Cell Biology, Physiology and Immunology, University of Córdoba, Campus de Rabanales, Edificio Severo-Ochoa, Planta 3, E-14014 Córdoba, Spain. e-mail:
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26
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Baragli A, Lanfranco F, Allasia S, Granata R, Ghigo E. Neuroendocrine and metabolic activities of ghrelin gene products. Peptides 2011; 32:2323-32. [PMID: 22056513 DOI: 10.1016/j.peptides.2011.10.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 10/03/2011] [Accepted: 10/25/2011] [Indexed: 12/15/2022]
Abstract
Acylated ghrelin (AG) is a 28 amino acid gastric peptide a natural ligand for the growth hormone secretagogue (GHS) receptor type 1a (GHS-R1a), endowed with GH-secreting and orexigenic properties. Besides, ghrelin exerts several peripheral metabolic actions, including modulation of glucose homeostasis and stimulation of adipogenesis. Notably, AG administration causes hyperglycemia in rodents as in humans. Ghrelin pleiotropy is supported by a widespread expression of the ghrelin gene, of GHS-R1a and other unknown ghrelin binding sites. The existence of alternative receptors for AG, of several natural ligands for GHS-R1a and of acylation-independent ghrelin non-neuroendocrine activities, suggests that there might be a complex 'ghrelin system' not yet completely explored. Moreover, the patho-physiological implications of unacylated ghrelin (UAG), and obestatin (Ob), the other two ghrelin gene-derived peptides, need to be clarified. Within the next few years, we may better understand the 'ghrelin system', where we might envisage clinical applications.
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Affiliation(s)
- Alessandra Baragli
- Laboratory of Molecular and Cellular Endocrinology, Division of Endocrinology, Department of Internal Medicine, University of Turin, Turin, Italy.
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Biagini G, Torsello A, Marinelli C, Gualtieri F, Vezzali R, Coco S, Bresciani E, Locatelli V. Beneficial effects of desacyl-ghrelin, hexarelin and EP-80317 in models of status epilepticus. Eur J Pharmacol 2011; 670:130-6. [DOI: 10.1016/j.ejphar.2011.08.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 07/28/2011] [Accepted: 08/17/2011] [Indexed: 11/26/2022]
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Frago LM, Baquedano E, Argente J, Chowen JA. Neuroprotective actions of ghrelin and growth hormone secretagogues. Front Mol Neurosci 2011; 4:23. [PMID: 21994488 PMCID: PMC3182030 DOI: 10.3389/fnmol.2011.00023] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/29/2011] [Indexed: 11/21/2022] Open
Abstract
The brain incorporates and coordinates information based on the hormonal environment, receiving information from peripheral tissues through the circulation. Although it was initially thought that hormones only acted on the hypothalamus to perform endocrine functions, it is now known that they in fact exert diverse actions on many different brain regions including the hypothalamus. Ghrelin is a gastric hormone that stimulates growth hormone secretion and food intake to regulate energy homeostasis and body weight by binding to its receptor, growth hormone secretagogues–GH secretagogue-receptor, which is most highly expressed in the pituitary and hypothalamus. In addition, ghrelin has effects on learning and memory, reward and motivation, anxiety, and depression, and could be a potential therapeutic agent in neurodegenerative disorders where excitotoxic neuronal cell death and inflammatory processes are involved.
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Affiliation(s)
- Laura M Frago
- Department of Pediatrics, Universidad Autónoma de Madrid Madrid, Spain
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Fetissov SO, Laviano A, Kalra S, Inui A. Update on ghrelin. INTERNATIONAL JOURNAL OF PEPTIDES 2010; 2010:963501. [PMID: 20798849 PMCID: PMC2925383 DOI: 10.1155/2010/963501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 04/14/2010] [Indexed: 12/18/2022]
Affiliation(s)
- Sergueï O. Fetissov
- Digestive System and Nutrition Laboratory (ADEN EA4311), Biomedical Research Institute, IFR23, Rouen 76183, France
| | | | - Satya Kalra
- Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Akio Inui
- Department of Behavioral Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8520, Japan
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