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Nie M, Zhang J, Bal M, Duran C, An SW, Zigman JM, Baum M, Hiremath C, Marciano DK, Wolf MTF. Ghrelin enhances tubular magnesium absorption in the kidney. Front Physiol 2024; 15:1363708. [PMID: 38638279 PMCID: PMC11024433 DOI: 10.3389/fphys.2024.1363708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 03/07/2024] [Indexed: 04/20/2024] Open
Abstract
Osteoporosis after bariatric surgery is an increasing health concern as the rate of bariatric surgery has risen. In animal studies mimicking bariatric procedures, bone disease, together with decreased serum levels of Ca2+, Mg2+ and the gastric hormone Ghrelin were described. Ghrelin regulates metabolism by binding to and activating the growth hormone secretagogue receptor (GHSR) which is also expressed in the kidney. As calcium and magnesium are key components of bone, we tested the hypothesis that Ghrelin-deficiency contributes to osteoporosis via reduced upregulation of the renal calcium channel TRPV5 and the heteromeric magnesium channel TRPM6/7. We expressed GHSR with TRPV5 or TRPM6/7 channel in HEK293 cells and treated them with purified Ghrelin. Whole-cell current density was analyzed by patch-clamp recording. Nephron-specific gene expression was performed by tubular microdissection followed by qPCR in wild-type (WT) mice, and immunofluorescent imaging of GHSR-eGFP mice. Tubular magnesium homeostasis was analyzed in GHSR-null and WT mice at baseline and after caloric restriction. After Ghrelin exposure, whole-cell current density did not change for TRPV5 but increased for TRPM6/7 in a dose-dependent fashion. Applying the Ghrelin-mimetic (D-Trp7, Ala8,D-Phe10)-α-MSH (6-11) amide without and with the GHSR antagonist (D-Lys3)-GHRP6, we confirmed the stimulatory role of Ghrelin towards TRPM6/7. As GHSR initiates downstream signaling via protein kinase A (PKA), we found that the PKA inhibitor H89 abrogated TRPM6/7 stimulation by Ghrelin. Similarly, transfected Gαs, but not the Gαs mutant Q227L, nor Gαi2, Gαq, or Gα13 upregulated TRPM6/7 current density. In microdissected TALs and DCTs similar levels of GHSR mRNA were detected. In contrast, TRPM6 mRNA was expressed in the DCT and also detected in the TAL at 25% expression compared to DCT. Immunofluorescent studies using reporter GHSR-eGFP mice showed a strong eGFP signal in the TAL but surprisingly displayed no eGFP signal in the DCT. In 3-, 6-, and 9-month-old GHSR-null and WT mice, baseline serum magnesium was not significantly different, but 24-h urinary magnesium excretion was elevated in 9-month-old GHSR-null mice. In calorically restricted GHSR-null mice, we detected excess urinary magnesium excretion and reduced serum magnesium levels compared to WT mice. The kidneys from calorically restricted WT mice showed upregulated gene expression of magnesiotropic genes Hnf1b, Cldn-16, Cldn-19, Fxyd-2b, and Parvalbumin compared to GHSR-null mice. Our in vitro studies show that Ghrelin stimulates TRPM6/7 via GHSR and Gαs-PKA signaling. The murine studies are consistent with Ghrelin-GHSR signaling inducing reduced urinary magnesium excretion, particularly in calorically restricted mice when Ghrelin levels are elevated. This effect may be mediated by Ghrelin-upregulation of TRPM6 in the TAL and/or upregulation of other magnesiotropic genes. We postulate that rising Ghrelin levels with hunger contribute to increased renal Mg2+ reabsorption to compensate for lack of enteral Mg2+ uptake.
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Affiliation(s)
- Mingzhu Nie
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jing Zhang
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Manjot Bal
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Claudia Duran
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Sung Wan An
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Pediatric Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, United States
| | - Jeffrey M. Zigman
- Department of Internal Medicine, Center for Hypothalamic Research, UTSW Medical Center, Dallas, TX, United States
| | - Michel Baum
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Chitkale Hiremath
- Department of Internal Medicine, Nephrology, and Department of Cell Biology, UTSW Medical Center, Dallas, TX, United States
| | - Denise K. Marciano
- Department of Internal Medicine, Nephrology, and Department of Cell Biology, UTSW Medical Center, Dallas, TX, United States
| | - Matthias T. F. Wolf
- Pediatric Nephrology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Pediatric Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, United States
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Shosha HM, Ebaid HM, Toraih EA, Abdelrazek HMA, Elrayess RA. Effect of monosodium glutamate on fetal development and progesterone level in pregnant Wistar Albino rats. Environ Sci Pollut Res Int 2023; 30:49779-49797. [PMID: 36787072 PMCID: PMC10104942 DOI: 10.1007/s11356-023-25661-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 01/27/2023] [Indexed: 02/15/2023]
Abstract
Monosodium glutamate (MSG) is a widespread flavor enhancer and stabilizer in manufactured or packaged foods that possess myriad adverse effects. This study aimed to evaluate the effect of MSG on placental progesterone receptors and fetal development. Thirty pregnant Wistar Albino rats were divided into three groups (ten/each). The control group (G1) gavaged distilled water only, low-dose treated group (G2) gavaged 3 g/kg MSG, and high-dose treated group (G3) gavaged 6 g/kg MSG from 1st to 18th days of gestation, and all pregnant rats were sacrificed on the 19th day of gestation. The effect of MSG on fetal weights, crown vertebral length (CVL), placental weight, placental ghrelin expression, and fetal skeleton examination were estimated. MSG induced a significant decrease in fetal weights, CVL lengths, placental weight, and ghrelin expression in both treatment groups compared to the control group. Several parts of the fetal skeleton showed incomplete ossification and delayed chondrification in which high-dose maternally treated fetuses were more affected. Many degenerative changes were detected in both maternal and fetal liver and kidney tissues in MSG-treated groups. Moreover, MSG caused a significant increase in serum ALT, ALP, and creatinine levels in pregnant rats' blood. Serum progesterone was only elevated in G3 on the 19th day of gestation. This study showed that the administration of MSG during pregnancy adversely influences fetal growth and skeletal development and caused several biochemical and histological changes in the maternal and fetal liver and kidney tissues which assure the toxic and teratogenic effects of MSG.
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Affiliation(s)
- Hadeer M Shosha
- Zoology Department, Faculty of Sciences, Suez Canal University, Ismailia, 41522, Egypt
| | - Hala M Ebaid
- Zoology Department, Faculty of Sciences, Suez Canal University, Ismailia, 41522, Egypt
| | - Eman A Toraih
- Department of Surgery, School of Medicine, Tulane University, New Orleans, LA, USA
- Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Heba M A Abdelrazek
- Department of Physiology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Ranwa A Elrayess
- Zoology Department, Faculty of Sciences, Suez Canal University, Ismailia, 41522, Egypt.
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Mlyczyńska E, Kieżun M, Kurowska P, Dawid M, Pich K, Respekta N, Daudon M, Rytelewska E, Dobrzyń K, Kamińska B, Kamiński T, Smolińska N, Dupont J, Rak A. New Aspects of Corpus Luteum Regulation in Physiological and Pathological Conditions: Involvement of Adipokines and Neuropeptides. Cells 2022; 11:957. [PMID: 35326408 PMCID: PMC8946127 DOI: 10.3390/cells11060957] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
The corpus luteum is a small gland of great importance because its proper functioning determines not only the appropriate course of the estrous/menstrual cycle and embryo implantation, but also the subsequent maintenance of pregnancy. Among the well-known regulators of luteal tissue functions, increasing attention is focused on the role of neuropeptides and adipose tissue hormones—adipokines. Growing evidence points to the expression of these factors in the corpus luteum of women and different animal species, and their involvement in corpus luteum formation, endocrine function, angiogenesis, cells proliferation, apoptosis, and finally, regression. In the present review, we summarize the current knowledge about the expression and role of adipokines, such as adiponectin, leptin, apelin, vaspin, visfatin, chemerin, and neuropeptides like ghrelin, orexins, kisspeptin, and phoenixin in the physiological regulation of the corpus luteum function, as well as their potential involvement in pathologies affecting the luteal cells that disrupt the estrous cycle.
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Abstract
The stomach hormone, ghrelin, which is released during food restriction, provides a link between circulating energy state and adaptive brain function. The maintenance of such homeostatic systems is essential for an organism to survive and thrive, and accumulating evidence points to ghrelin being a key regulator of adult hippocampal neurogenesis and memory function. Aberrant neurogenesis is linked to cognitive decline in aging and neurodegeneration. Therefore, identifying endogenous metabolic factors that regulate new adult-born neuron formation is an important objective in understanding the link between nutritional status and CNS function. Here, we review current developments in our understanding of ghrelin's role in regulating neurogenesis and memory function.
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Affiliation(s)
- Jeffrey S Davies
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, Swansea, United Kingdom.
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5
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Sato T, Ida T, Shiimura Y, Matsui K, Oishi K, Kojima M. Insights Into the Regulation of Offspring Growth by Maternally Derived Ghrelin. Front Endocrinol (Lausanne) 2022; 13:852636. [PMID: 35250893 PMCID: PMC8894672 DOI: 10.3389/fendo.2022.852636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
The regulation of fetal development by bioactive substances such as hormones and neuropeptides derived from the gestational mother is considered to be essential for the development of the fetus. On the other hand, it has been suggested that changes in the physiological state of the pregnant mother due to various factors may alter the secretion of these bioactive substances and induce metabolic changes in the offspring, such as obesity, overeating, and inflammation, thereby affecting postnatal growth and health. However, our knowledge of how gestational maternal bioactive substances modulate offspring physiology remains fragmented and lacks a systematic understanding. In this mini-review, we focus on ghrelin, which regulates growth and energy metabolism, to advance our understanding of the mechanisms by which maternally derived ghrelin regulates the growth and health of the offspring. Understanding the regulation of offspring growth by maternally-derived ghrelin is expected to clarify the fetal onset of metabolic abnormalities and lead to a better understanding of lifelong health in the next generation of offspring.
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Affiliation(s)
- Takahiro Sato
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
- *Correspondence: Takahiro Sato, ; Masayasu Kojima,
| | - Takanori Ida
- Division for Identification and Analysis of Bioactive Peptides, Department of Bioactive Peptides, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Yuki Shiimura
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, United States
| | - Kazuma Matsui
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
| | - Kanae Oishi
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
| | - Masayasu Kojima
- Division of Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Japan
- *Correspondence: Takahiro Sato, ; Masayasu Kojima,
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Buckinx A, De Bundel D, Kooijman R, Smolders I. Targeting the Ghrelin Receptor as a Novel Therapeutic Option for Epilepsy. Biomedicines 2022; 10:53. [PMID: 35052733 PMCID: PMC8773216 DOI: 10.3390/biomedicines10010053] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is a neurological disease affecting more than 50 million individuals worldwide. Notwithstanding the availability of a broad array of antiseizure drugs (ASDs), 30% of patients suffer from pharmacoresistant epilepsy. This highlights the urgent need for novel therapeutic options, preferably with an emphasis on new targets, since “me too” drugs have been shown to be of no avail. One of the appealing novel targets for ASDs is the ghrelin receptor (ghrelin-R). In epilepsy patients, alterations in the plasma levels of its endogenous ligand, ghrelin, have been described, and various ghrelin-R ligands are anticonvulsant in preclinical seizure and epilepsy models. Up until now, the exact mechanism-of-action of ghrelin-R-mediated anticonvulsant effects has remained poorly understood and is further complicated by multiple downstream signaling pathways and the heteromerization properties of the receptor. This review compiles current knowledge, and discusses the potential mechanisms-of-action of the anticonvulsant effects mediated by the ghrelin-R.
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Daniels JR, Ma JZ, Cao Z, Beger RD, Sun J, Schnackenberg L, Pence L, Choudhury D, Palevsky PM, Portilla D, Yu LR. Discovery of Novel Proteomic Biomarkers for the Prediction of Kidney Recovery from Dialysis-Dependent AKI Patients. Kidney360 2021; 2:1716-1727. [PMID: 34913041 PMCID: PMC8670726 DOI: 10.34067/kid.0002642021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND AKI requiring dialysis (AKI-D) is associated with prolonged hospitalization, mortality, and progressive CKD among survivors. Previous studies have examined only select urine or serum biomarkers for predicting kidney recovery from AKI. METHODS Serum samples collected on day 8 of randomized RRT from 72 patients enrolled in the Veteran's Affairs/National Institutes of Health Acute Renal Failure Trial Network study were analyzed by the SOMAscan proteomic platform to profile 1305 proteins in each sample. Of these patients, 38 recovered kidney function and dialysis was discontinued, whereas another 34 patients remained on dialysis by day 28. RESULTS Differential serum levels of 119 proteins, with 53 higher and 66 lower, were detected in samples from patients who discontinued dialysis, compared with patients who remained on dialysis by day 28. Patients were classified into tertiles on the basis of SOMAscan protein measurements for the 25 proteins most differentially expressed. The association of serum levels of each protein with kidney recovery was further evaluated using logistic regression analysis. Higher serum levels of CXCL11, CXCL2/CXCL3, CD86, Wnt-7a, BTK, c-Myc, TIMP-3, CCL5, ghrelin, PDGF-C, survivin, CA2, IL-9, EGF, and neuregulin-1, and lower levels of soluble CXCL16, IL1RL1, stanniocalcin-1, IL-6, and FGF23 when classified in tertiles were significantly associated with better kidney recovery. This significant association persisted for each of these proteins after adjusting for potential confounding risk factors including age, sex, cardiovascular SOFA score, congestive heart failure, diabetes, modality of intensive dialysis treatment, cause of AKI, baseline serum creatinine, day 8 urine volume, and estimated 60-day mortality risk. CONCLUSIONS These results suggest concerted changes between survival-related proteins and immune-regulatory chemokines in regulating angiogenesis, endothelial and epithelial remodeling, and kidney cell regeneration, illustrating potential mechanisms of kidney recovery. Thus, this study identifies potential novel predictive biomarkers of kidney recovery in patients with AKI-D.
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Affiliation(s)
- Jaclyn R. Daniels
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Jennie Z. Ma
- Division of Biostatistics, Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia,Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - Zhijun Cao
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Richard D. Beger
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Jinchun Sun
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Laura Schnackenberg
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Lisa Pence
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
| | - Devasmita Choudhury
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Virginia,Salem Veterans Affairs Medical Center, Salem, Virginia
| | - Paul M. Palevsky
- Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania,Renal-Electrolye Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Didier Portilla
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - Li-Rong Yu
- Division of Systems Biology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas
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Liang Y, Yin W, Yin Y, Zhang W. Ghrelin Based Therapy of Metabolic Diseases. Curr Med Chem 2021; 28:2565-2576. [PMID: 32538716 DOI: 10.2174/0929867327666200615152804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/04/2020] [Accepted: 05/18/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Ghrelin, a unique 28 amino acid peptide hormone secreted by the gastric X/A like cells, is an endogenous ligand of the growth hormone secretagogue receptor (GHSR). Ghrelin-GHSR signaling has been found to exert various physiological functions, including stimulation of appetite, regulation of body weight, lipid and glucose metabolism, and increase of gut motility and secretion. This system is thus critical for energy homeostasis. OBJECTIVE The objective of this review is to highlight the strategies of ghrelin-GHSR based intervention for therapy of obesity and its related metabolic diseases. RESULTS Therapeutic strategies of metabolic disorders targeting the ghrelin-GHSR pathway involve neutralization of circulating ghrelin by antibodies and RNA spiegelmers, antagonism of ghrelin receptor by its antagonists and inverse agonists, inhibition of ghrelin O-acyltransferase (GOAT), as well as potential pharmacological approach to decrease ghrelin synthesis and secretion. CONCLUSION Various compounds targeting the ghrelin-GHSR system have shown promising efficacy for the intervention of obesity and relevant metabolic disorders in animals and in vitro. Further clinical trials to validate their efficacy in human beings are urgently needed.
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Affiliation(s)
- Yuan Liang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wenzhen Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yue Yin
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Weizhen Zhang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
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Abstract
The nervous system is highly vulnerable to different factors which may cause injury followed by an acute or chronic neurodegeneration. Injury involves a loss of extracellular matrix integrity, neuronal circuitry disintegration, and impairment of synaptic activity and plasticity. Application of pleiotropic molecules initiating extracellular matrix reorganization and stimulating neuronal plasticity could prevent propagation of the degeneration into the tissue surrounding the injury. To find an omnipotent therapeutic molecule, however, seems to be a fairly ambitious task, given the complex demands of the regenerating nervous system that need to be fulfilled. Among the vast number of candidates examined so far, the neuropeptide and hormone ghrelin holds within a very promising therapeutic potential with its ability to cross the blood-brain barrier, to balance metabolic processes, and to stimulate neurorepair and neuroactivity. Compared with its well-established systemic effects in treatment of metabolism-related disorders, the therapeutic potential of ghrelin on neuroregeneration upon injury has received lesser appreciation though. Here, we discuss emerging concepts of ghrelin as an omnipotent player unleashing developmentally related molecular cues and morphogenic cascades, which could attenuate and/or counteract acute and chronic neurodegeneration.
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Affiliation(s)
- Irina Stoyanova
- Department of Anatomy and Cell Biology, Medical University Varna, Varna, Bulgaria
| | - David Lutz
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany
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Perpétuo L, Voisin PM, Amado F, Hirtz C, Vitorino R. Ghrelin and adipokines: An overview of their physiological role, antimicrobial activity and impact on cardiovascular conditions. Vitam Horm 2021; 115:477-509. [PMID: 33706959 DOI: 10.1016/bs.vh.2020.12.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The human body has many different hormones that interact with each other and with other factors such as proteins, cell receptors and metabolites. There is still a limited understanding of some of the underlying biological mechanisms of some hormones. In the past decades, science and technology have made major advancements in regard to innovation and knowledge in fields such as medicine. However, some conditions are complex and have many variables that their full picture is still unclear, even though some of these conditions have an alarming rate of incidence and serious health consequences. Conditions such as type 2 diabetes, obesity, nonalcoholic liver disease (NAFLD), cancer in its different forms and even mental conditions, such as Alzheimer's disease, are some of the most common diseases in the 21st century. These conditions are relevant not only because of their high incidence on the general population, but also because of their severity. In this chapter, we present an overview of cardiovascular (CV) diseases. According to the World Health Organization (WHO), cardiovascular diseases, such as coronary artery disease (CAD), heart attack, cardiomyopathy and heart failure (among others), are the number one cause of death worldwide. In 2016, it was estimated that 17.9 million people died from CV diseases, representing more than 30% of all global deaths. Approximately 95% of people who died from CV diseases were so-called "premature deaths" because were referenced to individuals under the age of 70 years old. In this chapter we described some of the hormones that may have an impact on CV diseases, including ghrelin, a peptide that is mostly produced in the stomach, known to induce hunger. Ghrelin is linked to an increase in body fat, i.e., adipose tissue in animals. For this reason, we also included the adipokines leptin, adiponectin and resistin. The main objectives of this chapter are to present the state of the art knowledge concerning the mechanisms of each hormone relevant to CV diseases; to compile data and results that further elucidate the relevance of these peptides for several physiological events, conditions and diseases; and to discuss the metabolic impact of each hormone. We established connections between multiple peptides and the underlying condition/disease with tools such as STRING, referring to research using databases, such as UniProt, DisGeNET and Proteomics DB. Fig. 1 shows a network that summarizes the information presented in this chapter, which serves as a visual representation.
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Affiliation(s)
- Luís Perpétuo
- iBiMED, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | | | - Francisco Amado
- LAQV-REQUIMTE, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal
| | - Christophe Hirtz
- IRMB, Univ Montpellier, INSERM, CHU Montpellier, CNRS, Montpellier, France
| | - Rui Vitorino
- iBiMED, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal; UnIC, Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal; LAQV-REQUIMTE, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal.
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11
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Fritz EM, Singewald N, De Bundel D. The Good, the Bad and the Unknown Aspects of Ghrelin in Stress Coping and Stress-Related Psychiatric Disorders. Front Synaptic Neurosci 2020; 12:594484. [PMID: 33192444 PMCID: PMC7652849 DOI: 10.3389/fnsyn.2020.594484] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022] Open
Abstract
Ghrelin is a peptide hormone released by specialized X/A cells in the stomach and activated by acylation. Following its secretion, it binds to ghrelin receptors in the periphery to regulate energy balance, but it also acts on the central nervous system where it induces a potent orexigenic effect. Several types of stressors have been shown to stimulate ghrelin release in rodents, including nutritional stressors like food deprivation, but also physical and psychological stressors such as foot shocks, social defeat, forced immobilization or chronic unpredictable mild stress. The mechanism through which these stressors drive ghrelin release from the stomach lining remains unknown and, to date, the resulting consequences of ghrelin release for stress coping remain poorly understood. Indeed, ghrelin has been proposed to act as a stress hormone that reduces fear, anxiety- and depression-like behaviors in rodents but some studies suggest that ghrelin may - in contrast - promote such behaviors. In this review, we aim to provide a comprehensive overview of the literature on the role of the ghrelin system in stress coping. We discuss whether ghrelin release is more than a byproduct of disrupted energy homeostasis following stress exposure. Furthermore, we explore the notion that ghrelin receptor signaling in the brain may have effects independent of circulating ghrelin and in what way this might influence stress coping in rodents. Finally, we examine how the ghrelin system could be utilized as a therapeutic avenue in stress-related psychiatric disorders (with a focus on anxiety- and trauma-related disorders), for example to develop novel biomarkers for a better diagnosis or new interventions to tackle relapse or treatment resistance in patients.
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Affiliation(s)
- Eva Maria Fritz
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, University of Innsbruck, Innsbruck, Austria
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy and CMBI, University of Innsbruck, Innsbruck, Austria
| | - Dimitri De Bundel
- Department of Pharmaceutical Sciences, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
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Elabadlah H, Hameed R, D'Souza C, Mohsin S, Adeghate EA. Exogenous Ghrelin Increases Plasma Insulin Level in Diabetic Rats. Biomolecules 2020; 10:E633. [PMID: 32325912 DOI: 10.3390/biom10040633] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/09/2020] [Accepted: 04/15/2020] [Indexed: 12/13/2022] Open
Abstract
Ghrelin, a 28-amino acid peptide, is a strong growth hormone secretagogue and a regulator of food intake. In addition, ghrelin is thought to play a role in insulin secretion and in glucose homeostasis. A lot of contradictory data have been reported in the literature regarding the co-localization of ghrelin with other hormones in the islet of Langerhans, its role in insulin secretion and attenuation of type 2 diabetes mellitus. In this study, we investigate the effect of chronic ghrelin treatment on glucose, body weight and insulin level in normal and streptozotocin-induced diabetic male Wistar rats. We have also examined the distribution pattern and co-localization of ghrelin with insulin in pancreatic islet cells using immunohistochemistry and immune-electron microscopy and the ability of ghrelin to stimulate insulin release from the CRL11065 beta cell line. Control, non-diabetic groups received intraperitoneal injection of normal saline, while treated groups received intraperitoneal injection of 5 µg/kg body weight of ghrelin (amino acid chain 24–51) on a daily basis for a duration of four weeks. Our results show that the administration of ghrelin increases the number of insulin-secreting beta cells and serum insulin level in both normal and diabetic rats. We also demonstrated that ghrelin co-localizes with insulin in pancreatic islet cells and that the pattern of ghrelin distribution is altered after the onset of diabetes. Moreover, ghrelin at a dose of 10−6 M and 10−12 M increased insulin release from the CRL11065 beta cell line. In summary, ghrelin co-localizes with insulin in the secretory granules of pancreatic beta cells and enhances insulin production.
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Affiliation(s)
- Robert H. Mak
- Department of Pediatrics Oregon Health & Science University Portland, Oregon, USA
| | - Wai Cheung
- Department of Pediatrics Oregon Health & Science University Portland, Oregon, USA
| | - Jonathan Purnell
- Department of Medicine Oregon Health & Science University Portland, Oregon, USA
- Center for the Study of Weight Regulation Oregon Health & Science University Portland, Oregon, USA
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Szczepańska M, Szprynger K, Mazur B, Zwolińska D, Kilis-Pstrusińska K, Makulska I. Plasma Ghrelin Levels in Children with Chronic Renal Failure on Peritoneal Dialysis. Perit Dial Int 2020. [DOI: 10.1177/089686080702700114] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objectives Malnutrition and loss of appetite represent a serious problem in children with chronic renal failure. Ghrelin is a newly described hormone involved in control of growth hormone secretion, stimulation of food intake, and regulation of energy balance. Methods Plasma ghrelin levels were compared between 12 children on automated peritoneal dialysis (APD) and 9 children on conservative treatment of chronic renal failure. Eight healthy children matched for age and body mass index (BMI) served as a control group. Results Plasma ghrelin levels were similar in children on APD (698.3 ± 59.7 pg/mL) and children on conservative treatment (675.4 ± 41.9 pg/mL) compared to healthy controls (700.1 ± 24.7 pg/mL). There was no difference in plasma ghrelin levels in children with chronic renal failure regardless of the method of treatment (peritoneal dialysis vs conservative treatment). The plasma ghrelin index was similar in all three investigated groups: APD 40.2 ± 8.7 vs conservative treatment 39.1 ± 5.6 vs controls 41.0 ± 7.8 (pg/mL)/BMI (kg/m2). Plasma ghrelin levels did not correlate with age, duration of dialysis treatment, height, weight, BMI, creatinine and urea levels, adequacy parameters, or nightly glucose load. Conclusion Plasma ghrelin levels in children on APD were not different from levels in children on conservative treatment or healthy controls with comparable BMI. The persistent state of toxic influence of uremic end-products could be responsible for such a lack of correlation with anthropometrical parameters. Further studies on a larger group of children on APD are needed to clarify the effect of ghrelin on nutritional status in children with chronic renal failure.
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Affiliation(s)
- Maria Szczepańska
- Clinic of Pediatrics, Nephrology and Endocrinology of Childhood, Department of Pediatrics, Silesian University of Medicine, Zabrze
| | - Krystyna Szprynger
- Clinic of Pediatrics, Nephrology and Endocrinology of Childhood, Department of Pediatrics, Silesian University of Medicine, Zabrze
| | - Bogdan Mazur
- Clinic of Pediatrics, Nephrology and Endocrinology of Childhood, Department of Pediatrics, Silesian University of Medicine, Zabrze
| | - Danuta Zwolińska
- Department of Pediatric Nephrology, Wroclaw Medical University, Wroclaw, Poland
| | | | - Irena Makulska
- Department of Pediatric Nephrology, Wroclaw Medical University, Wroclaw, Poland
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Blanco AM, Cortés R, Bertucci JI, Soletto L, Sánchez E, Valenciano AI, Cerdá-Reverter JM, Delgado MJ. Brain transcriptome profile after CRISPR-induced ghrelin mutations in zebrafish. Fish Physiol Biochem 2020; 46:1-21. [PMID: 31673996 DOI: 10.1007/s10695-019-00687-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
Ghrelin (GRL) is a gut-brain hormone with a role in a wide variety of physiological functions in mammals and fish, which points out the ghrelinergic system as a key element for the appropriate biological functioning of the organism. However, many aspects of the multifunctional nature of GRL remain to be better explored, especially in fish. In this study, we used the CRISPR/Cas9 genome editing technique to generate F0 zebrafish in which the expression of grl is compromised. Then, we employed high-throughput mRNA sequencing (RNA-seq) to explore changes in the brain transcriptome landscape associated with the silencing of grl. The CRISPR/Cas9 technique successfully edited the genome of F0 zebrafish resulting in individuals with considerably lower levels of GRL mRNAs and protein and ghrelin O-acyl transferase (goat) mRNAs in the brain, intestine, and liver compared to wild-type (WT) zebrafish. Analysis of brain transcriptome revealed a total of 1360 differentially expressed genes (DEGs) between the grl knockdown (KD) and WT zebrafish, with 664 up- and 696 downregulated DEGs in the KD group. Functional enrichment analysis revealed that DEGs are highly enriched for terms related to morphogenesis, metabolism (especially of lipids), entrainment of circadian clocks, oxygen transport, apoptosis, and response to stimulus. The present study offers valuable information on the central genes and pathways implicated in functions of GRL, and points out the possible involvement of this peptide in some novel functions in fish, such as apoptosis and oxygen transport.
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Affiliation(s)
- Ayelén Melisa Blanco
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040, Madrid, Spain
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Vigo, Spain
| | - Raúl Cortés
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Ribera de Cabanes, 12595, Torre de la Sal, Castellón, Spain
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O'Higgins, Fábrica, 1990, Santiago, Chile
| | | | - Lucia Soletto
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Ribera de Cabanes, 12595, Torre de la Sal, Castellón, Spain
| | - Elisa Sánchez
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Ribera de Cabanes, 12595, Torre de la Sal, Castellón, Spain
| | - Ana Isabel Valenciano
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040, Madrid, Spain
| | - José Miguel Cerdá-Reverter
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas, Ribera de Cabanes, 12595, Torre de la Sal, Castellón, Spain.
| | - María Jesús Delgado
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040, Madrid, Spain.
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Parada D D, Peña G KB, Vives M, Molina A, Mayayo E, Riu F, Sabench F, Del Castillo D. Quantitative and Topographic Analysis by Immunohistochemical Expression of Ghrelin Gastric Cells in Patients with Morbid Obesity. Diabetes Metab Syndr Obes 2020; 13:2855-2864. [PMID: 32884313 PMCID: PMC7443401 DOI: 10.2147/dmso.s260483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/18/2020] [Indexed: 12/19/2022] Open
Abstract
PURPOSE The cellular distribution of ghrelin positive cells is not well defined. The aim of the study is to quantify and determine the distribution of ghrelin cells in gastric mucosa in patients with morbid obesity and relate this finding to gender, comorbidities, gastritis, and plasmatic levels of acyl and desacylghrelin before and after laparoscopic sleeve gastrectomy. PATIENT AND METHODS We performed a study on 61 patients with BMI≥50 kg/m2 operated by laparoscopic sleeve gastrectomy. Three gastric regions were analyzed by histopathology and immunohistology. Blood sample was taken before surgery, and at 6 and 12 months post-surgery, to study the plasma levels of ghrelin isoforms. RESULTS Ghrelin cells are present in all regions of the gastric mucosa, with a greater number in the body and the fundus. Difference was found in the antrum between male and female patients (p=0.018). Patients with arterial hypertension also showed a lower level of cells in antrum (p<0.05). Acylghrelin levels after surgery were significantly lower (32.83+5.6 pg/mL to 10.09+11.8 pg/mL, p<0.05). Values of desacylghrelin tended to decrease but no significant variation was observed (207.4+39.3 pg/mL to 188.84+52.3 pg/mL). CONCLUSION Our patients show ghrelin cells in all areas of the stomach. Gender, comorbidities, and gastritis are determinant on gastric ghrelin-producing cells distribution.
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Affiliation(s)
- David Parada D
- Pathology Service, University Hospital of Sant Joan. Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Karla B Peña G
- Pathology Service, University Hospital of Sant Joan. Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Margarida Vives
- Surgery Service, University Hospital of Sant Joan, Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Alicia Molina
- Surgery Service, University Hospital of Sant Joan, Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Emilio Mayayo
- Pathology Service, University Hospital of Joan XXIII, Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Frances Riu
- Pathology Service, University Hospital of Sant Joan. Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Fàtima Sabench
- Surgery Service, University Hospital of Sant Joan, Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
| | - Daniel Del Castillo
- Surgery Service, University Hospital of Sant Joan, Faculty of Medicine, IISPV, “Rovira i Virgili” University, Reus, Tarragona, Spain
- Correspondence: Daniel Del Castillo Head Surgery Department, Hospital Universitari Sant Joan, Facultat de Medicina, U.R.V., Reus, Spain Email
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Dar SA, Srivastava PP, Rather MA, Varghese T, Rasool SI, Gupta S. Molecular and computational analysis of Ghrelin, growth hormone Secretagogues receptor and mRNA expression of Growth-related genes after exogenous administered ghrelin peptide in Labeo rohita. Int J Biol Macromol 2020; 142:756-768. [DOI: 10.1016/j.ijbiomac.2019.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/09/2019] [Accepted: 10/02/2019] [Indexed: 01/09/2023]
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Abstract
Ghrelin is a gastric hormone circulating in acylated (AG) and unacylated (UnAG) forms. This narrative review aims at presenting current emerging knowledge on the impact of ghrelin forms on energy balance and metabolism. AG represents ~ 10% of total plasma ghrelin, has an appetite-stimulating effect and is the only form for which a receptor has been identified. Moreover, other metabolic AG-induced effects have been reported, including the modulation of glucose homeostasis with stimulation of liver gluconeogenesis, the increase of fat mass and the improvement of skeletal muscle mitochondrial function. On the other hand, UnAG has no orexigenic effects, however recent reports have shown that it is directly involved in the modulation of skeletal muscle energy metabolism by improving a cluster of interlinked functions including mitochondrial redox activities, tissue inflammation and insulin signalling and action. These findings are in agreement with human studies which show that UnAG circulating levels are positively associated with insulin sensitivity both in metabolic syndrome patients and in a large cohort from the general population. Moreover, ghrelin acylation is regulated by a nutrient sensor mechanism, specifically set on fatty acids availability. These recent findings consistently point towards a novel independent role of UnAG as a regulator of muscle metabolic pathways maintaining energy status and tissue anabolism. While a specific receptor for UnAG still needs to be identified, recent evidence strongly supports the hypothesis that the modulation of ghrelin-related molecular pathways, including those involved in its acylation, may be a potential novel target in the treatment of metabolic derangements in disease states characterized by metabolic and nutritional complications.Level of evidence Level V, narrative review.
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Affiliation(s)
- Gianluca Gortan Cappellari
- Department of Medical, Surgical and Health Sciences, University of Trieste, Strada di Fiume, 447, 34149, Trieste, Italy.
| | - Rocco Barazzoni
- Department of Medical, Surgical and Health Sciences, University of Trieste, Strada di Fiume, 447, 34149, Trieste, Italy.
- Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Trieste, Italy.
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Buntwal L, Sassi M, Morgan AH, Andrews ZB, Davies JS. Ghrelin-Mediated Hippocampal Neurogenesis: Implications for Health and Disease. Trends Endocrinol Metab 2019; 30:844-859. [PMID: 31445747 DOI: 10.1016/j.tem.2019.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/21/2019] [Accepted: 07/08/2019] [Indexed: 12/13/2022]
Abstract
There is a close relationship between cognition and nutritional status, however, the mechanisms underlying this relationship require elucidation. The stomach hormone, ghrelin, which is released during food restriction, provides a link between circulating energy state and adaptive brain function. The maintenance of such homeostatic systems is essential for an organism to thrive and survive, and accumulating evidence points to ghrelin being key in promoting adult hippocampal neurogenesis and memory. Aberrant neurogenesis is linked to cognitive decline in ageing and neurodegeneration. Therefore, identifying endogenous metabolic factors that regulate new adult-born neurone formation is an important objective in understanding the link between nutritional status and central nervous system (CNS) function. Here, we review current developments in our understanding of ghrelin's role in regulating neurogenesis and memory function.
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Affiliation(s)
- Luke Buntwal
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Martina Sassi
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Alwena H Morgan
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK
| | - Zane B Andrews
- Department of Physiology, Biomedical Discovery Unit, Monash University, Melbourne, Australia
| | - Jeffrey S Davies
- Molecular Neurobiology, Institute of Life Sciences, School of Medicine, Swansea University, SA2 8PP, UK.
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El Zein N, Abdallah MS, Daher CF, Mroueh M, Stephan J, Bahous SA, Eid A, Faour WH. Ghrelin modulates intracellular signalling pathways that are critical for podocyte survival. Cell Biochem Funct 2019; 37:245-255. [DOI: 10.1002/cbf.3397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 04/01/2019] [Indexed: 11/08/2022]
Affiliation(s)
| | - Maya S. Abdallah
- Gilbert and Rose‐Marie Chagoury, School of MedicineLebanese American University Byblos Lebanon
- Institut Européen des MembranesUniversité de Montpellier Montpellier France
| | - Costantine F. Daher
- School of Arts and Sciences, Natural Sciences DepartmentLebanese American University Byblos Lebanon
| | - Mohammad Mroueh
- Department of Pharmaceutical Sciences, School of PharmacyLebanese American University Byblos Lebanon
| | - Joseph Stephan
- Gilbert and Rose‐Marie Chagoury, School of MedicineLebanese American University Byblos Lebanon
| | - Sola Aoun Bahous
- Gilbert and Rose‐Marie Chagoury, School of MedicineLebanese American University Byblos Lebanon
| | - Assaad Eid
- Department of Anatomy, Cell Biology and Physiology, Faculty of MedicineAmerican University of Beirut Beirut Lebanon
| | - Wissam H. Faour
- Gilbert and Rose‐Marie Chagoury, School of MedicineLebanese American University Byblos Lebanon
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Abstract
Background Ghrelin is a gastro-duodenal hormone which plays a major role in the regulation of food intake, energy balance and gastrokinesis. Ghrelin represents a novel biological marker for assessment of the presence as well as the severity of liver cirrhosis. We aimed to measure the level of plasma ghrelin in patients with liver cirrhosis (compensated and decompensated) and to correlate its level with different studied clinical and laboratory parameters. Subjects and methods 40 cirrhotic patients were included in a cross-sectional study and divided equally according to the Child-Pugh classification into Group I: patients with compensated liver cirrhosis (Child A), and Group II: patients with decompensated liver cirrhosis (Child B|C). Also, 20 age and sex matched healthy subjects were included as a control group (Group III). All patients were subjected to: full history taking, full clinical examination, routine biochemical studies together with estimation of plasma ghrelin level, assessment of the severity of liver disease according to Child-Pugh classification, also, abdominal ultrasonography was done. Results Plasma ghrelin level was low among cirrhotic patients (both compensated and decompensated) in comparison to normal control subjects. Conclusion Ghrelin can be used as a serum biomarker for detection and assessment of the severity of liver cirrhosis.
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Affiliation(s)
| | - P E S Salem
- Alexandria University, Faculty of Medicine, Egypt
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Jeong YO, Shin SJ, Park JY, Ku BK, Song JS, Kim JJ, Jeon SG, Lee SM, Moon M. MK-0677, a Ghrelin Agonist, Alleviates Amyloid Beta-Related Pathology in 5XFAD Mice, an Animal Model of Alzheimer's Disease. Int J Mol Sci 2018; 19:E1800. [PMID: 29912176 DOI: 10.3390/ijms19061800] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive deficits, neuroinflammation, and neuronal death. The primary pathogenic cause is believed to be the accumulation of pathogenic amyloid beta (Aβ) assemblies in the brain. Ghrelin, which is a peptide hormone predominantly secreted from the stomach, is an endogenous ligand for the growth hormone secretagogue-receptor type 1a (GHS-R1a). MK-0677 is a ghrelin agonist that potently stimulates the GHS-R1a ghrelin receptor. Interestingly, previous studies have shown that ghrelin improves cognitive impairments and attenuates neuronal death and neuroinflammation in several neurological disorders. However, it is unknown whether MK-0677 can affect Aβ accumulation or Aβ-mediated pathology in the brains of patients with AD. Therefore, we examined the effects of MK-0677 administration on AD-related pathology in 5XFAD mice, an Aβ-overexpressing transgenic mouse model of AD. MK-0677 was intraperitoneally administered to three-month-old 5XFAD mice. To visualize Aβ accumulation, neuroinflammation, and neurodegeneration, thioflavin-S staining and immunostaining with antibodies against Aβ (4G8), ionized calcium-binding adaptor molecule 1 (Iba-1), glial fibrillary acidic protein (GFAP), neuronal nuclear antigen (NeuN), and synaptophysin were conducted in the neocortex of 5XFAD and wild-type mice, and to evaluate changes of phosphorylated cyclic adenosine monophosphate (cAMP) response element binding protein (pCREB) levels, immunostaining with antibody against pCREB was performed in dentate gyrus of the hippocampus of 5XFAD and wild-type mice. The histological analyses indicated that MK-0677-treated 5XFAD mice showed reduced Aβ deposition, gliosis, and neuronal and synaptic loss in the deep cortical layers, and inhibited the decrement of pCREB levels in dentate gyrus of the hippocampus compared to vehicle-treated 5XFAD mice. Our results showed that activation of the ghrelin receptor with MK-0677 inhibited the Aβ burden, neuroinflammation, and neurodegeneration, which suggested that MK-0677 might have potential as a treatment of the early phase of AD.
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Morris LS, Voon V, Leggio L. Stress, Motivation, and the Gut-Brain Axis: A Focus on the Ghrelin System and Alcohol Use Disorder. Alcohol Clin Exp Res 2018; 42:10.1111/acer.13781. [PMID: 29797564 PMCID: PMC6252147 DOI: 10.1111/acer.13781] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 05/17/2018] [Indexed: 01/04/2023]
Abstract
Since its discovery, the gut hormone, ghrelin, has been implicated in diverse functional roles in the central nervous system. Central and peripheral interactions between ghrelin and other hormones, including the stress-response hormone cortisol, govern complex behavioral responses to external cues and internal states. By acting at ventral tegmental area dopaminergic projections and other areas involved in reward processing, ghrelin can induce both general and directed motivation for rewards, including craving for alcohol and other alcohol-seeking behaviors. Stress-induced increases in cortisol seem to increase ghrelin in the periphery, suggesting a pathway by which ghrelin influences how stressful life events trigger motivation for rewards. However, in some states, ghrelin may be protective against the anxiogenic effects of stressors. This critical review brings together a dynamic and growing literature, that is, at times inconsistent, on the relationships between ghrelin, central reward-motivation pathways, and central and peripheral stress responses, with a special focus on its emerging role in the context of alcohol use disorder.
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Affiliation(s)
- Laurel S. Morris
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK
- Department of Psychology, University of Cambridge, UK
- Mood and Anxiety Disorders Program, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Valerie Voon
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, UK
- Department of Psychiatry, University of Cambridge, UK
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA
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McDonald H, Peart J, Kurniawan N, Galloway G, Royce S, Samuel CS, Chen C. Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in a mouse model of acute myocardial infarction. Physiol Rep 2018; 6:e13699. [PMID: 29756411 PMCID: PMC5949285 DOI: 10.14814/phy2.13699] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 04/14/2018] [Indexed: 12/11/2022] Open
Abstract
Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI-injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post-MI. MI-HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI-VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF-β1 expression, myofibroblast differentiation and an increase in collagen-degrading MMP-13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX-dependent decrease in troponin-I, IL-1β and TNF-α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.
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Affiliation(s)
- Hayley McDonald
- School of Biomedical ScienceUniversity of QueenslandBrisbaneAustralia
| | - Jason Peart
- Menzies Health Institute of QueenslandGriffith UniversityGold CoastAustralia
| | - Nyoman Kurniawan
- Centre for Advanced ImagingUniversity of QueenslandBrisbaneAustralia
| | - Graham Galloway
- Centre for Advanced ImagingUniversity of QueenslandBrisbaneAustralia
| | - Simon Royce
- Cardiovascular Disease ProgramBiomedical Discovery Institute and Department of PharmacologyMonash UniversityVictoriaAustralia
- Central Clinical SchoolMonash UniversityVictoriaAustralia
| | - Chrishan S. Samuel
- Cardiovascular Disease ProgramBiomedical Discovery Institute and Department of PharmacologyMonash UniversityVictoriaAustralia
| | - Chen Chen
- School of Biomedical ScienceUniversity of QueenslandBrisbaneAustralia
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Abstract
Osteoblast activating peptide (OBAP) is a newly discovered peptide detected in the rat stomach, which has a major role in osteogenesis. Recently, we revealed its localization in the parietal cells of the rat stomach. There have been no data regarding OBAP expression in the kidney, despite its role in calcium reabsorption in renal tubules. The current study aimed to inspect the expression of OBAP in the kidney of twelve 10-week-old male C3H/HeNJc1 mice using immunohistochemistry, and immunoelectron microscopic localization. The immunohistochemical investigation revealed an OBAP positive reaction mainly in the medulla, which was stronger than the cortex of the kidney and was concentrated in the distal convoluted tubules (DCT), connecting tubules (CT), and the thick limbs of the loop of Henle (HL). Moreover, we clarified that the OBAP was co-distributed with ghrelin and calbindin (markers of the DCT). Interestingly, immunoelectron microscopy demonstrated that OBAP was concentrated in the mitochondrial inner membrane of the DCT and CT. Based on these results, it was concluded that the mitochondria of the DCT, CT, and HL of the mice kidney generate OBAP. Furthermore, our results suggest that OBAP might have a role in the regulation of calcium reabsorption by the renal tubule; however, further investigations are required to clarify this potential role.
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Affiliation(s)
- Ahmed E Noreldin
- Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Tottori, Japan; Department of Histology and Cytology, Faculty of Veterinary Medicine, The Scientific Campus, Damanhour University, Damanhour, Egypt
| | - Yaser Hosny Ali Elewa
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Histology and Cytology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Yasuhiro Kon
- Laboratory of Anatomy, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Katsuhiko Warita
- Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Tottori, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan
| | - Yoshinao Z Hosaka
- Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Tottori, Japan; Department of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Japan.
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Abstract
BACKGROUND Cancer sufferers are amongst the most malnourished of all the patient groups. Studies have shown that ghrelin, a gut hormone can be a potential therapeutic agent for cachexia (wasting syndrome) associated with cancer. A variety of mechanisms of action of ghrelin in people with cancer cachexia have been proposed. However, safety and efficacy of ghrelin for cancer-associated cachexia have not been systematically reviewed. The aim of this review was to assess whether ghrelin is associated with better food intake, body composition and survival than other options for adults with cancer cachexia. OBJECTIVES To assess the efficacy and safety of ghrelin in improving food intake, body composition and survival in people with cachexia associated with cancer. SEARCH METHODS We searched CENTRAL, MEDLINE and Embase without language restrictions up to July 2017. We also searched for ongoing studies in trials registers, performed handsearching, checked bibliographic references of relevant articles and contacted authors and experts in the field to seek potentially relevant research. We applied no restrictions on language, date, or publication status. SELECTION CRITERIA We included randomised controlled (parallel-group or cross-over) trials comparing ghrelin (any formulation or route of administration) with placebo or an active comparator in adults (aged 18 years and over) who met any of the international criteria for cancer cachexia. DATA COLLECTION AND ANALYSIS Two review authors independently assessed studies for eligibility. Two review authors then extracted data and assessed the risk of bias for individual studies using standard Cochrane methodology. For dichotomous variables, we planned to calculate risk ratio with 95% confidence intervals (CI) and for continuous data, we planned to calculate mean differences (MD) with 95% CI. We assessed the evidence using GRADE and created 'Summary of findings' tables. MAIN RESULTS We screened 926 individual references and identified three studies that satisfied the inclusion criteria. Fifty-nine participants (37 men and 22 women) aged between 54 and 78 years were randomised initially, 47 participants completed the treatment. One study had a parallel design and two had a cross-over design. The studies included people with a variety of cancers and also differed in the dosage, route of administration, frequency and duration of treatment.One trial, which compared ghrelin with placebo, found that ghrelin improved food intake (very low-quality evidence) and had no adverse events (very low-quality evidence). Due to unavailability of data we were unable to report on comparisons for ghrelin versus no treatment or alternative experimental treatment modalities, or ghrelin in combination with other treatments or ghrelin analogues/ghrelin mimetics/ghrelin potentiators. Two studies compared a higher dose of ghrelin with a lower dose of ghrelin, however due to differences in study designs and great diversity in the treatment provided we did not pool the results. In both trials, food intake did not differ between participants on higher-dose and lower-dose ghrelin. None of the included studies assessed data on body weight. One study reported higher adverse events with a higher dose as compared to a lower dose of ghrelin.All studies were at high risk of attrition bias and bias for size of the study. Risk of bias in other domains was unclear or low.We rated the overall quality of the evidence for primary outcomes (food intake, body weight, adverse events) as very low. We downgraded the quality of the evidence due to lack of data, high or unclear risk of bias of the studies and small study size. AUTHORS' CONCLUSIONS There is insufficient evidence to be able to support or refute the use of ghrelin in people with cancer cachexia. Adequately powered randomised controlled trials focusing on evaluation of safety and efficacy of ghrelin in people with cancer cachexia is warranted.
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Affiliation(s)
- Mahalaqua Nazli Khatib
- Division of Evidence Synthesis; School of Epidemiology and Public Health & Department of Physiology, Datta Meghe Institute of Medical Sciences, Sawangi Meghe, Wardha, Maharashtra, India, 442004
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Sirini MA, Anchordoquy JM, Anchordoquy JP, Pascua AM, Nikoloff N, Carranza A, Relling AE, Furnus CC. The presence of acylated ghrelin during in vitro maturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development. ZYGOTE 2017; 25:601-11. [PMID: 28929981 DOI: 10.1017/S0967199417000478] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The aim of this study was to investigate the effects of acylated ghrelin supplementation during in vitro maturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus-oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. The in vitro effects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.
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Bonior J, Ceranowicz P, Gajdosz R, Kuśnierz-Cabala B, Pierzchalski P, Warzecha Z, Dembiński A, Pędziwiatr M, Kot M, Leja-Szpak A, Nawrot-Porąbka K, Link-Lenczowski P, Olszanecki R, Bartuś K, Jaworek J. Molecular Ghrelin System in the Pancreatic Acinar Cells: The Role of the Polypeptide, Caerulein and Sensory Nerves. Int J Mol Sci 2017; 18:E929. [PMID: 28468316 DOI: 10.3390/ijms18050929] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/09/2017] [Accepted: 04/19/2017] [Indexed: 12/25/2022] Open
Abstract
Ghrelin (GHRL) is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Experimental studies showed that GHRL protects the stomach and pancreas against acute damage, but the effect of GHRL on pancreatic acinar cells was still undetermined. Aim: To investigate the effect of GHRL and caerulein on the functional ghrelin system in pancreatic acinar cells taking into account the role of sensory nerves (SN). Methods: Experiments were carried out on isolated pancreatic acinar cells and AR42J cells. Before acinar cells isolation, GHRL was administered intraperitoneally at a dose of 50 µg/kg to rats with intact SN or with capsaicin deactivation of SN (CDSN). After isolation, pancreatic acinar cells were incubated in caerulein-free or caerulein containing solution. AR42J cells were incubated under basal conditions and stimulated with caerulein, GHRL or a combination of the above. Results: Incubation of isolated acinar cells with caerulein inhibited GHS-R and GHRL expression at the level of mRNA and protein in those cells. Either in rats with intact SN or with CDSN, administration of GHRL before isolation of acinar cells increased expression of GHRL and GHS-R in those cells and reversed the caerulein-induced reduction in expression of those parameters. Similar upregulation of GHS-R and GHRL was observed after administration of GHRL in AR42J cells. Conclusions: GHRL stimulates its own expression and expression of its receptor in isolated pancreatic acinar cells and AR42J cells on the positive feedback pathway. This mechanism seems to participate in the pancreatoprotective effect of GHRL in the course of acute pancreatitis.
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Edwards A, Abizaid A. Clarifying the Ghrelin System's Ability to Regulate Feeding Behaviours Despite Enigmatic Spatial Separation of the GHSR and Its Endogenous Ligand. Int J Mol Sci 2017; 18:E859. [PMID: 28422060 DOI: 10.3390/ijms18040859] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 12/23/2022] Open
Abstract
Ghrelin is a hormone predominantly produced in and secreted from the stomach. Ghrelin is involved in many physiological processes including feeding, the stress response, and in modulating learning, memory and motivational processes. Ghrelin does this by binding to its receptor, the growth hormone secretagogue receptor (GHSR), a receptor found in relatively high concentrations in hypothalamic and mesolimbic brain regions. While the feeding and metabolic effects of ghrelin can be explained by the effects of this hormone on regions of the brain that have a more permeable blood brain barrier (BBB), ghrelin produced within the periphery demonstrates a limited ability to reach extrahypothalamic regions where GHSRs are expressed. Therefore, one of the most pressing unanswered questions plaguing ghrelin research is how GHSRs, distributed in brain regions protected by the BBB, are activated despite ghrelin’s predominant peripheral production and poor ability to transverse the BBB. This manuscript will describe how peripheral ghrelin activates central GHSRs to encourage feeding, and how central ghrelin synthesis and ghrelin independent activation of GHSRs may also contribute to the modulation of feeding behaviours.
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Lin TC, Hsiao M. Ghrelin and cancer progression. Biochim Biophys Acta Rev Cancer 2017; 1868:51-7. [PMID: 28238732 DOI: 10.1016/j.bbcan.2017.02.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 01/27/2017] [Accepted: 02/18/2017] [Indexed: 12/22/2022]
Abstract
Ghrelin is a small peptide with 28 amino acids, and has been characterized as the ligand of the growth hormone secretagogue receptor (GHSR). In addition to its original function in stimulating pituitary growth hormone release, ghrelin is multifunctional and plays a role in the regulation of energy balance, gastric acid release, appetite, insulin secretion, gastric motility and the turnover of gastric and intestinal mucosa. The discovery of ghrelin and GHSR expression beyond normal tissues suggests its role other than physiological function. Emerging evidences have revealed ghrelin's function in regulating several processes related to cancer progression, especially in metastasis and proliferation. We further show the relative GHRL and GHSR expression in pan-cancers from The Cancer Genome Atlas (TCGA), suggesting the potential pathological role of the axis in cancers. This review focuses on ghrelin's biological function in cancer progression, and reveals its clinical significance especially the impact on cancer patient outcome.
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Blanco AM, Bertucci JI, Sánchez-Bretaño A, Delgado MJ, Valenciano AI, Unniappan S. Ghrelin modulates gene and protein expression of digestive enzymes in the intestine and hepatopancreas of goldfish (Carassius auratus) via the GHS-R1a: Possible roles of PLC/PKC and AC/PKA intracellular signaling pathways. Mol Cell Endocrinol 2017; 442:165-181. [PMID: 28042022 DOI: 10.1016/j.mce.2016.12.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/28/2016] [Accepted: 12/28/2016] [Indexed: 12/13/2022]
Abstract
Ghrelin, a multifunctional gut-brain hormone, is involved in the regulation of gastric functions in mammals. This study aimed to determine whether ghrelin modulates digestive enzymes in goldfish (Carassius auratus). Immunofluorescence microscopy found colocalization of ghrelin, GHS-R1a and the digestive enzymes sucrase-isomaltase, aminopeptidase A, trypsin and lipoprotein lipase in intestinal and hepatopancreatic cells. In vitro ghrelin treatment in intestinal and hepatopancreas explant culture led to a concentration- and time-dependent modulation (mainly stimulatory) of most of the digestive enzymes tested. The ghrelin-induced upregulations of digestive enzyme expression were all abolished by preincubation with the GHS-R1a ghrelin receptor antagonist [D-Lys3]-GHRP-6, and most of them by the phospholipase C inhibitor U73122 or the protein kinase A inhibitor H89. This indicates that ghrelin effects on digestive enzymes are mediated by GHS-R1a, partly by triggering the PLC/PKC and AC/PKA intracellular signaling pathways. These data suggest a role for ghrelin on digestive processes in fish.
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Affiliation(s)
- Ayelén Melisa Blanco
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain.
| | - Juan Ignacio Bertucci
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Avenida Intendente Marinos Km. 8,2, 7130 Chascomús, Buenos Aires, Argentina.
| | - Aída Sánchez-Bretaño
- Department of Pharmacology and Toxicology, and Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive, GA 30310 Atlanta, GA, United States.
| | - María Jesús Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain.
| | - Ana Isabel Valenciano
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, José Antonio Nováis 12, 28040 Madrid, Spain.
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada.
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Rindi G, Torsello A, Locatelli V, Solcia E. Ghrelin Expression and Actions: A Novel Peptide for an Old Cell Type of the Diffuse Endocrine System. Exp Biol Med (Maywood) 2016; 229:1007-16. [PMID: 15522836 DOI: 10.1177/153537020422901004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ghrelin is a gastric peptide involved in food intake control and growth hormone release. Its cell localization has been defined in distinct ghrelin cells of the gastric mucosa in humans and other mammals. Ghrelin production was also described in a number of other sites of the diffuse endocrine system, including the pituitary, thyroid, lung, pancreas, adrenal gland, and intestine. In addition, ghrelin cells were identified early during fetal life and in the placenta and gonads. Finally, endocrine growths and tumors of the diffuse endocrine system may present ghrelin-producing cells, and in a few cases high levels of circulating ghrelin were reported. Besides its well-defined orexigenic role, ghrelin is likely to exert a local paracrine role similar to other brain-gut axis hormones. This review aims to summarize recent data on ghrelin cell distribution in the diffuse endocrine system and discuss local and general ghrelin function during development, adulthood, and endocrine tumor development.
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Affiliation(s)
- Guido Rindi
- Department of Pathology, University of Parma, Italy.
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Kraemer RR, Durand RJ, Acevedo EO, Johnson LG, Kraemer GR, Hebert EP, Castracane VD. Rigorous Running Increases Growth Hormone and Insulin-Like Growth Factor-I Without Altering Ghrelin. Exp Biol Med (Maywood) 2016; 229:240-6. [PMID: 14988516 DOI: 10.1177/153537020422900304] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
It has been suggested that ghrelin may play a role in growth hormone (GH) responses to exercise. The present study was designed to determine whether ghrelin, GH, insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 (IGFBP-3) were altered by a progressively intense running protocol. Six well-trained male volunteers completed a progressively intense intermittent exercise trial on a treadmill that included four exercise intensities: 60%, 75%, 90%, and 100% of Vo2max. Blood samples were collected before exercise, after each exercise intensity, and at 15 and 30 mins following the exercise protocol. Subjects also completed a separate control trial at the same time of day that excluded exercise. GH changed significantly over time, and GH area under the curve (AUC) was significantly higher in the exercise trial than the control trial. Area under the curve IGF-I levels for the exercise trial were significantly higher than the control trial. There was no difference in the ghrelin and IGFBP-3 responses to the exercise and control trials. Pearson correlation coefficients revealed significant relationships between ghrelin and both IGF-I and IGFBP-3; however, no relationship between ghrelin and GH was found. In conclusion, intense running produces increases in total IGF-I concentrations, which differs from findings in previous studies using less rigorous running protocols and less frequent blood sampling regimens. Moreover, running exercise that produces substantial increases in GH does not affect peripheral ghrelin levels; however, significant relationships between ghrelin and both IGF-I and IGFBP-3 exist during intense intermittent running and recovery, which warrants further investigation.
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Affiliation(s)
- R R Kraemer
- Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, Louisiana 70402, USA.
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Yang SY, Lin SL, Chen YM, Wu VC, Yang WS, Wu KD. A low-salt diet increases the expression of renal sirtuin 1 through activation of the ghrelin receptor in rats. Sci Rep 2016; 6:32787. [PMID: 27600292 DOI: 10.1038/srep32787] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 08/15/2016] [Indexed: 11/30/2022] Open
Abstract
Previous studies have shown that sirtuin 1 (Sirt1) is renoprotective; however, details regarding its distribution and functions in the kidney remain unknown. Here, we demonstrated that Sirt1 was mainly expressed in the tubulointerstitial cells of normal rat kidneys and was co-localized with aquaporin 2, indicating it may be involved in water/salt regulation. Renal Sirt1 expression increased in the non-glomerular cytoplasmic portion of the kidney after a 24-h fast, but no significant changes in Sirt1 expression occurred after water loading (50 mL/kg) or 24-h water deprivation. After consuming a low-salt (0.075%) or 60% calorie restriction diet for 7 days, Sirt1 expression in the rat kidney was significantly increased, whereas a high-salt (8%) diet did not change the level of Sirt1 expression. The low-salt diet also increased Sirt1 expression in the heart, muscle, brain, and fat tissues. The increased Sirt1 that was observed in rats on a low-salt diet was associated with increased ghrelin expression in the distal nephron, with both molecules exhibiting similar distribution patterns. An in vitro experiment suggested that ghrelin increases Sirt1 expression in cortical collecting duct cells by activating ghrelin receptors. Our study indicates that this ‘ghrelin-Sirt1 system’ may participate in regulating sodium reabsorption in the distal nephron.
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Xu L, Yu L, Chi N, Wang W, Liu G, Shi W. Plasma ghrelin levels in association with left ventricular function and nutritional status in dialysis patients. Biomed Rep 2016; 5:45-49. [PMID: 27347404 PMCID: PMC4907035 DOI: 10.3892/br.2016.666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/15/2016] [Indexed: 12/21/2022] Open
Abstract
The present study investigated the association between ghrelin levels and the cardiac function and malnutrition of dialysis patients. The aim was to examine the conducive use of exogenous ghrelin to improve the malnutrition, protect the cardiovascular function with dialysis patients in the future. The study included 30 continuous ambulatory peritoneal dialysis (CAPD) patients and 30 hemodialysis (HD) patients undertaking treatment between March 2013 and March 2014. The control group included a total of 30 healthy physical examinees. The plasma ghrelin levels were measured by the enzyme-linked immunosorbent assay to collect the clinical materials and biochemical parameters. The plasma ghrelin levels were 4.28±1.07, 4.63±1.08 and 2.00±0.48 ng/ml in the CAPD, HD and control groups, respectively, and statistical significance was identified between the three groups; F=75.106, P<0.0001. The plasma ghrelin levels in the CAPD group were positively correlated with left ventricular ejection fraction (LVEF) (r=0.506, P=0.004) and were negatively correlated with body mass index (BMI) (r=−0.556, P=0.001). The plasma ghrelin levels in the CAPD and HD groups were positively correlated with serum creatinine (Scr) and blood urea nitrogen (BUN). In conclusion, the plasma ghrelin levels of patients in the CAPD and HD groups were higher compared to those of the control group, which demonstrated that dialysis patients could not effectively remove the plasma ghrelin. The present study found that the plasma ghrelin levels were positively correlated with LVEF, and high levels of ghrelin will exhibit protective effects on the cardiovascular function of CAPD patients. Plasma ghrelin levels were positively correlated with Scr and BUN levels in CAPD and HD patients, and were negatively correlated with BMI in CAPD patients, which showed that ghrelin was correlated with malnutrition of dialysis patients.
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Affiliation(s)
- Libin Xu
- Southern Medical University, Guangzhou, Guangdong 510515, P.R. China; Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510515, P.R. China; Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Lei Yu
- Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Ning Chi
- Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Wenhao Wang
- Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Guoping Liu
- Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Wei Shi
- Southern Medical University, Guangzhou, Guangdong 510515, P.R. China; Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510515, P.R. China
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Yanagimoto Y, Takiguchi S, Miyazaki Y, Makino T, Takahashi T, Kurokawa Y, Yamasaki M, Miyata H, Nakajima K, Mori M, Doki Y. Plasma ghrelin levels as a predictor of adverse renal events due to cisplatin-based chemotherapy in patients with esophageal cancer. Jpn J Clin Oncol 2016; 46:421-6. [DOI: 10.1093/jjco/hyw004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/04/2016] [Indexed: 12/15/2022] Open
Affiliation(s)
- Yoshitomo Yanagimoto
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Shuji Takiguchi
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Yasuhiro Miyazaki
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Tomoki Makino
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Tsuyoshi Takahashi
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Yukinori Kurokawa
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Makoto Yamasaki
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Hiroshi Miyata
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Kiyokazu Nakajima
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Masaki Mori
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
| | - Yuichiro Doki
- Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan
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Zhang W, Shu L. Upregulation of miR-21 by Ghrelin Ameliorates Ischemia/Reperfusion-Induced Acute Kidney Injury by Inhibiting Inflammation and Cell Apoptosis. DNA Cell Biol 2016; 35:417-25. [PMID: 27152763 DOI: 10.1089/dna.2016.3231] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Renal ischemia-reperfusion (I/R) injury can be caused by cardiac surgery, renal vascular obstruction, and kidney transplantation, mainly leading to acute kidney injury (AKI), which is complicated by lack of effective preventative and therapeutic strategies. Ghrelin has recently been reported to possess anti-inflammatory properties in several types of cells; however, little attention has been given to the role of ghrelin in I/R-induced AKI. The aim of this study is to explore the role of ghrelin in I/R-induced AKI. In this study, an I/R-induced rat AKI model and a hypoxia-induced NRK-52E cell I/R model were successfully constructed. Ghrelin expression was increased significantly in these rat and cell models. After enhancing ghrelin level by injecting exogenous ghrelin into rats or transfecting a ghrelin-pcDNA3.1 vector into renal tubular epithelial cells, we observed that I/R-induced AKI can be ameliorated by ghrelin, as shown by alterations in histology, as well as changes in serum creatinine (SCr) level, cell apoptosis, and the levels of inflammatory factors. Based on the importance of microRNA-21 (miR-21) in renal disease and the modulation effect of ghrelin on miR-21 in gastric epithelial cells, we tested whether miR-21 participates in the protective effect of ghrelin on I/R-induced AKI. Ghrelin could upregulate the PI3K/AKT signaling pathway by increasing the miR-21 level, which led to the protective effect of ghrelin on I/R-induced AKI by inhibiting the inflammatory response and renal tubular epithelial cell apoptosis. Our research identifies that ghrelin can ameliorate I/R-induced AKI by upregulating miR-21, which advances the understanding of mechanisms by which ghrelin ameliorates I/R-induced AKI.
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Affiliation(s)
- Wanzhe Zhang
- 1 Department of Nephrology, The Second Affiliated Hospital of Zhengzhou University , Zhengzhou, China
| | - Liliang Shu
- 2 Department of Cardiovascular Surgery, The First Affiliated Hospital of Zhengzhou University , Zhengzhou, China
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Kaiya H, Kangawa K, Miyazato M. Ghrelin receptor in Japanese fire belly newt, Cynops pyrrhogaster. Comp Biochem Physiol B Biochem Mol Biol 2015; 189:15-22. [DOI: 10.1016/j.cbpb.2015.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/19/2015] [Accepted: 07/03/2015] [Indexed: 12/20/2022]
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Mosa RMH, Zhang Z, Shao R, Deng C, Chen J, Chen C. Implications of ghrelin and hexarelin in diabetes and diabetes-associated heart diseases. Endocrine 2015; 49:307-23. [PMID: 25645463 DOI: 10.1007/s12020-015-0531-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/12/2015] [Indexed: 02/07/2023]
Abstract
Ghrelin and its synthetic analog hexarelin are specific ligands of growth hormone secretagogue (GHS) receptor. GHS have strong growth hormone-releasing effect and other neuroendocrine activities such as stimulatory effects on prolactin and adrenocorticotropic hormone secretion. Recently, several studies have reported other beneficial functions of GHS that are independent of GH. Ghrelin and hexarelin, for examples, have been shown to exert GH-independent cardiovascular activity. Hexarelin has been reported to regulate peroxisome proliferator-activated receptor gamma (PPAR-γ) in macrophages and adipocytes. PPAR-γ is an important regulator of adipogenesis, lipid metabolism, and insulin sensitization. Ghrelin also shows protective effects on beta cells against lipotoxicity through activation of phosphatidylinositol-3 kinase/protein kinase B, c-Jun N-terminal kinase (JNK) inhibition, and nuclear exclusion of forkhead box protein O1. Acylated ghrelin (AG) and unacylated ghrelin (UAG) administration reduces glucose levels and increases insulin-producing beta cell number, and insulin secretion in pancreatectomized rats and in newborn rats treated with streptozotocin, suggesting a possible role of GHS in pancreatic regeneration. Therefore, the discovery of GHS has opened many new perspectives in endocrine, metabolic, and cardiovascular research areas, suggesting the possible therapeutic application in diabetes and diabetic complications especially diabetic cardiomyopathy. Here, we review the physiological roles of ghrelin and hexarelin in the protection and regeneration of beta cells and their roles in the regulation of insulin release, glucose, and fat metabolism and present their potential therapeutic effects in the treatment of diabetes and diabetic-associated heart diseases.
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Lin TC, Liu YP, Chan YC, Su CY, Lin YF, Hsu SL, Yang CS, Hsiao M. Ghrelin promotes renal cell carcinoma metastasis via Snail activation and is associated with poor prognosis. J Pathol 2015; 237:50-61. [PMID: 25925728 DOI: 10.1002/path.4552] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/09/2015] [Accepted: 04/23/2015] [Indexed: 01/04/2023]
Abstract
Ghrelin is an appetite-regulating molecule that promotes growth hormone (GH) release and food intake through growth hormone secretagogue receptor (GHS-R). Recently, high ghrelin levels have been detected in various types of human cancer. Ghrelin expression is observed in proximal and distal renal tubules, where renal cell carcinoma (RCC) arises. However, whether ghrelin is up-regulated and promotes renal cell carcinogenesis remains obscure. In this study, we observed that ghrelin was highly expressed in renal tumours, especially in metastatic RCC. In addition, high ghrelin levels correlated with poor outcome, lymph node and distant metastasis. The addition of ghrelin promoted the migration ability of RCC cell lines 786-0, ACHN and A-498. Furthermore, knockdown of ghrelin expression reduced in vitro migration and in vivo metastasis, suggesting a requirement for ghrelin accumulation in the microenvironment for RCC metastasis. Analysis of microarray signatures using Ingenuity Pathway Analysis (IPA) and MetaCore pointed to the potential regulation by ghrelin of Snail, a transcriptional repressor of E-cadherin. We further observed that Ghrelin increased the expression, nuclear translocation and promoter-binding activity of Snail. Snail silencing blocked the ghrelin-mediated effects on E-cadherin repression and cell migration. Snail-E-cadherin regulation was mediated by GHS-R-triggered Akt phosphorylation at Ser473 and Thr308. Pretreatment with PI3K inhibitors, LY294002 and wortmannin, as well as Akt siRNA, decreased ghrelin-induced Akt phosphorylation, Snail promoter binding activity and migration. Taken together, our findings indicate that ghrelin can activate Snail function via the GHS-R-PI3K-Akt axis, which may contribute to RCC metastasis. The microarray raw data were retrieved from the Cancer Genome Atlas (TCGA) [KIRC gene expression (IlluminaHiSeq) dataset].
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Affiliation(s)
| | - Yu-Peng Liu
- Department of Genome Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | | | - Chia-Yi Su
- Genomics Research Centre, Academia Sinica, Taipei, Taiwan
| | - Yuan-Feng Lin
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shih-Lan Hsu
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Chung-Shi Yang
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan
| | - Michael Hsiao
- Genomics Research Centre, Academia Sinica, Taipei, Taiwan
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Aygen B, Kucuksu M, Aydin S, Ozercan IH. Effect of enalapril maleate on ghrelin levels in metabolic syndrome in rats. Peptides 2015; 67:39-44. [PMID: 25784288 DOI: 10.1016/j.peptides.2015.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/05/2015] [Accepted: 03/05/2015] [Indexed: 12/13/2022]
Abstract
We have explored how enalapril affects ghrelin levels in serum and renal tissues of rats with fructose-induced MetS, using 5-week-old Wistar albino male rats weighing 220 ± 20 g. They divided into 5 groups: (i) control (CT), no fructose supplement fed on standard rat pellet and tap water for 60 days, (ii) metabolic syndrome (MetS) fed with 10% fructose for 60 days, (iii) rats after metabolic syndrome developed treated with enalapril over 30 days (MetS+E30), (iv) rats in which only enalapril was administered for 60 days (E60), and (v) MetS-treated with enalapril for 60 days (MetS+E60). Enalapril maleate was given at 20mg/kg per day by gavage. Fasting serum insulin, uric acid, triglyceride, low-density lipoprotein cholesterol and total cholesterol levels were significantly higher, and the amount of high density lipoprotein cholesterol, and acylated and desacyl ghrelin levels was significantly lower in the MetS groups. Ghrelins were significantly lower in all 3 groups, which were administered enalapril than that of MetS and the control group. Immunohistochemical staining showed that the density of ghrelin was parallel to the serum levels of the peptide. Ghrelin immunoreactivity in the kidneys was of moderate density in the distal and collecting tubules, mild density in the proximal tubule and glomeruli, whereas the density decreased in the MetS group and other enalapril-treated groups. In conclusion, ghrelin levels in MetS groups were significantly lower than control group, and thus Enalapril treatment improves components of MetS and has direct effects on serum ghrelin levels that are independent of MetS.
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Affiliation(s)
- Bilge Aygen
- Department of Nephrology, Firat University, Faculty of Medicine, Elazig, 23119, Turkey.
| | - Mehmet Kucuksu
- Department of Nephrology, Firat University, Faculty of Medicine, Elazig, 23119, Turkey
| | - Suleyman Aydin
- Department of Medical Biochemistry (Firat Hormones Research Group), Firat University, Faculty of Medicine, Elazig, 23119, Turkey.
| | - Ibrahim Hanifi Ozercan
- Department of Medical Pathology, Firat University, Faculty of Medicine, Elazig, 23119, Turkey
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Abstract
Ghrelin is a stomach-derived orexigenic hormone with a wide range of physiological functions. Elucidation of the regulation of the circulating ghrelin level would lead to a better understanding of appetite control in body energy homeostasis. Earlier studies revealed that circulating ghrelin levels are under the control of both acute and chronic energy status: at the acute scale, ghrelin levels are increased by fasting and decreased by feeding, whereas at the chronic scale, they are high in obese subjects and low in lean subjects. Subsequent studies revealed that nutrients, hormones, or neural activities can influence circulating ghrelin levels in vivo. Recently developed in vitro assay systems for ghrelin secretion can assess whether and how individual factors affect ghrelin secretion from cells. In this review, on the basis of numerous human, animal, and cell-based studies, we summarize current knowledge on the regulation of circulating ghrelin levels and enumerate the factors that influence ghrelin levels.
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Affiliation(s)
- Hiroshi Iwakura
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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Tang J, Lin J. Relationship between ghrelin and gastrointestinal diseases. Shijie Huaren Xiaohua Zazhi 2014; 22:5447-5453. [DOI: 10.11569/wcjd.v22.i35.5447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ghrelin is a newly found 28-amino acid brain-gut peptide, which is mainly secreted by the gastric mucosa. It has two forms, acyl-ghrelin and des-acyl ghrelin, and the former is the major active form. Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor and plays an important role in regulating food intake, gastric acid secretion, gastrointestinal motility, gastric mucosa protection, and inhibition of inflammatory reaction in paracrine, autocrine and endocrine manners. Recent studies have found that ghrelin levels are abnormal in a variety of gastrointestinal diseases, such as Helicobacter pylori infection, peptic ulcer, functional dyspepsia, inflammatory bowel disease, pancreatitis, tumors and so on, suggesting that ghrelin may be involved in the pathogenesis of these diseases. Ghrelin may become an index for disease diagnosis and prognosis evaluation and a new target for treatment of gastrointestinal diseases.
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Abstract
The orexigenic hormone ghrelin acts like a hunger signal, released by the stomach in response to nutritional status. However, ghrelin and its receptor in the kidney may play other biological roles. Kemp and colleagues identify that ghrelin stimulates renal Na+ absorption through cAMP-dependent trafficking of ENaC in the cortical collecting duct. While ghrelin seems to be a physiological regulator of ENaC, future studies are necessary to clarify its physiological and pathological roles in sodium homeostasis.
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Affiliation(s)
- George Seki
- Department of Internal Medicine, University of Tokyo, Tokyo, Japan.
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Sato T, Ida T, Nakamura Y, Shiimura Y, Kangawa K, Kojima M. Physiological roles of ghrelin on obesity. Obes Res Clin Pract 2014; 8:e405-13. [DOI: 10.1016/j.orcp.2013.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/28/2013] [Accepted: 10/08/2013] [Indexed: 02/06/2023]
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Invernizzi M, Carda S, Cisari C. Possible synergism of physical exercise and ghrelin-agonists in patients with cachexia associated with chronic heart failure. Aging Clin Exp Res 2014; 26:341-51. [PMID: 24347122 DOI: 10.1007/s40520-013-0186-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 11/29/2013] [Indexed: 12/24/2022]
Abstract
The occurrence of cachexia of multifactorial etiology in chronic heart failure (CHF) is a common and underestimated condition that usually leads to poor outcome and low survival rates, with high direct and indirect costs for the Health Care System. Recently, a consensus definition on cachexia has been reached, leading to a growing interest by the scientific community in this condition, which characterizes the last phase of many chronic diseases (i.e., cancer, acquired immunodeficiency syndrome). The etiology of cachexia is multifactorial and the underlying pathophysiological mechanisms are essentially the following: anorexia and malnourishment; immune overactivity and systemic inflammation; and endocrine disorders (anabolic/catabolic imbalance and resistance to growth hormone). In this paper, we review the main pathophysiological mechanisms underlying CHF cachexia, focusing also on the broad spectrum of actions of ghrelin and ghrelin agonists, and their possible use in combination with physical exercise to contrast CHF cachexia.
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García-Cáceres C, Fuente-Martín E, Díaz F, Granado M, Argente-Arizón P, Frago LM, Freire-Regatillo A, Barrios V, Argente J, Chowen JA. The opposing effects of ghrelin on hypothalamic and systemic inflammatory processes are modulated by its acylation status and food intake in male rats. Endocrinology 2014; 155:2868-80. [PMID: 24848869 DOI: 10.1210/en.2014-1074] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ghrelin is an endogenous hormone that stimulates appetite and adipose tissue accrual. Both the acylated (AG) and non-acylated (DAG) isoforms of this hormone are also reported to exert anti-inflammatory and protective effects systemically and in the central nervous system. As inflammatory processes have been implicated in obesity-associated secondary complications, we hypothesized that this natural appetite stimulator may protect against negative consequences resulting from excessive food intake. Adult male Wistar rats were treated icv (5 μg/day) with AG, DAG, the ghrelin mimetic GH-releasing peptide (GHRP)-6, AG, and pair-fed with controls (AG-pf) or saline for 14 days. Regardless of food intake AG increased visceral adipose tissue (VAT) and decreased circulating cytokine levels. However, AG reduced cytokine production in VAT only in rats fed ad libitum. Hypothalamic cytokine production was increased in AG-treated rats fed ad libitum and by DAG, but intracellular inflammatory signaling pathways associated with insulin and leptin resistance were unaffected. Gliosis was not observed in response to any treatment as glial markers were either reduced or unaffected. AG, DAG, and GHRP-6 stimulated production of hypothalamic insulin like-growth factor I that is involved in cell protective mechanisms. In hypothalamic astrocyte cell cultures AG decreased tumor necrosis factorα and DAG decreased interleukin-1β mRNA levels, suggesting direct anti-inflammatory effects on astrocytes. Thus, whereas ghrelin stimulates food intake and weight gain, it may also induce mechanisms of cell protection that help to detour or delay systemic inflammatory responses and hypothalamic gliosis due to excess weight gain, as well as its associated pathologies.
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Affiliation(s)
- Cristina García-Cáceres
- Hospital Infantil Universitario Niño Jesús, Department of Endocrinology, Instituto de Investigación La Princesa, Universidad Autónoma de Madrid and Centro de Investigación Biomédica en Red (CIBER) de la Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28009 Madrid, Spain
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Affiliation(s)
- Yuanjie Mao
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Takeshi Tokudome
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Ichiro Kishimoto
- From the Department of Biochemistry (Y.M., T.T.) and Department of Endocrinology and Metabolism (I.K.), National Cerebral and Cardiovascular Center, Osaka, Japan.
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Montazerifar F, Karajibani M, Gorgij F, Akbari O. Malnutrition Markers and Serum Ghrelin Levels in Hemodialysis Patients. Int Sch Res Notices 2014; 2014:765895. [PMID: 27433541 DOI: 10.1155/2014/765895] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 09/28/2014] [Accepted: 10/02/2014] [Indexed: 11/18/2022]
Abstract
Objective. The aim of study was to investigate the changes levels of serum ghrelin in HD patients and its relationship to some malnutrition markers compared with healthy controls. Methods. Forty-five patients on hemodialysis and forty healthy controls were studied. Biochemical parameters and serum ghrelin levels were measured. Both daily dietary intakes and body mass index (BMI) assessments were performed for evaluation of nutritional status. Results. Ghrelin concentrations were significantly reduced in patients undergoing hemodialysis when compared to healthy controls (5 ± 0.68 (1.1–18.5) pg/mL versus 7.8 ± 0.84 (2.4–18.3) pg/mL; P = 0.004). BMI and serum albumin in HD patients were markedly reduced compared to controls. The patients with an insufficient intake of energy and protein demonstrated slightly lower levels of serum ghrelin. A negative correlation between serum ghrelin concentration with age (r = −0.34, P = 0.02), BUN (r = −0.26, P < 0.01), and serum creatinine (r = −0.27, P < 0.01) was observed in HD patients. Conclusions. The findings suggest that decreased ghrelin levels in HD patients might be associated with anorexia. Further studies are needed to determine changes in serum ghrelin levels during dialysis and to clarify whether the decrease in ghrelin levels contributes to the malnutrition that is common in these patients.
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