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Das N, Addanki PK. Biochemical Examination of Plasma Ghrelin Levels in Individuals Afflicted With Chronic Periodontal Disease: A Comparative Study. Cureus 2024; 16:e56536. [PMID: 38646303 PMCID: PMC11027441 DOI: 10.7759/cureus.56536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 03/20/2024] [Indexed: 04/23/2024] Open
Abstract
OBJECTIVE This study intended to assess plasma ghrelin levels in individuals with chronic periodontitis and analyze potential associations with bone turnover indicators, serum cytokines, and periodontal parameters. MATERIAL AND METHODS The research contained 80 patients each with 40 individuals with periodontally healthy controls (C) (28 males, 12 females) and 40 chronic periodontitis (CP) patients (29 males, 11 females). The blood samples were analyzed for soluble receptor activator nuclear factor kappa B ligand (sRANKL), interleukin-1 beta (IL-1β), total and acylated ghrelin, tumor necrosis factor-alpha (TNF-α), osteocalcin (OSC) and alkaline phosphatase (ALP), and periodontal parameters were recorded. RESULTS The CP group had considerably higher plasma concentrations of both acylated and total ghrelin than the C group (p<0.05). Gender-based investigation showed substantial differences only among men in both groups (p<0.05). Hence, no significant modifications were identified in serum sRANKL, TNFα, and ALP levels between the groups. However, there was a notable difference in serum OSC and IL-1β levels in the CP group (p<0.05). Furthermore, total ghrelin/acylated ghrelin and total ghrelin/ALP revealed positive correlations. No significant association was found between symptoms and ghrelin levels. CONCLUSION The study findings indicate elevated levels of ghrelin and acylated ghrelin in male CP patients.
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Affiliation(s)
- Neelam Das
- Department of Periodontology, Rama Dental College Hospital & Research Centre, Kanpur, IND
| | - Pavan Kumar Addanki
- Department of Periodontology, Kamineni Institute of Dental Sciences, Narketpally, IND
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2
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Rahate PS, Kolte RA, Kolte AP, Lathiya VN, Gupta M, Chari S. Evaluation of stress, serum and salivary ghrelin and cortisol levels in smokers and non-smokers with stage iii periodontitis - A cross-sectional study. J Periodontol 2021; 93:1131-1140. [PMID: 34859428 DOI: 10.1002/jper.21-0373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/14/2021] [Accepted: 10/21/2021] [Indexed: 11/11/2022]
Abstract
BACKGROUND The present study aimed to investigate the serum and salivary ghrelin and cortisol levels in smokers and non-smokers with Stage III Periodontitis. METHODS The present study comprised of a total of 90 systemically healthy patients categorized in three groups: Group I- Periodontally healthy patients; Group II- Non-smokers with Stage III Periodontitis and Group III- Smokers with Stage III periodontitis. Clinical parameters of Probing pocket depth (PPD), Clinical attachment levels (CAL), Plaque Index (PI), Gingival Index (GI) and Papillary Bleeding Index (PBI)were recorded and biochemical parameters of serum and salivary ghrelin and cortisol levels were analyzed via Enzyme Linked Immunosorbent Assay (ELISA). Stress levels were assessed using Zung's self-rating depression scale. RESULTS Serum and salivary ghrelin values were found to be higher in Group II (620.25 ± 260.86 pg/ml, 892.40 ± 271.65 pg/ml respectively) as compared to Group III. Similarly, salivary as well as serum cortisol levels were higher in Group III (20.78 ± 9.23 pg/ml, 399.37 ±189.21 pg/ml respectively) as compared to Group II (16.36 ± 8.88 pg/ml, 320.68 ± 107.01 pg/ml respectively). In Group III, a direct correlation was observed between stress, serum and salivary cortisol levels while an inverse correlation was found between stress, serum and salivary ghrelin levels. Group III showed a greater number of depressed patients followed by Group II and I. CONCLUSION As per the results smokers with Stage III Periodontitis exhibit an elevated stress and cortisol levels, lower serum and salivary ghrelin levels as compared to the non-smokers. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Priyanka S Rahate
- Department of Periodontics & Implant Dentistry, VSPM Dental College and Research Centre, Nagpur, India
| | - Rajashri A Kolte
- Department of Periodontics & Implant Dentistry, VSPM Dental College and Research Centre, Nagpur, India
| | - Abhay P Kolte
- Department of Periodontics & Implant Dentistry, VSPM Dental College and Research Centre, Nagpur, India
| | - Vrushali N Lathiya
- Department of Periodontics & Implant Dentistry, VSPM Dental College and Research Centre, Nagpur, India
| | - Madhur Gupta
- Department of Biochemistry, NKP Salve Institute of Medical Science, Nagpur, India
| | - Suresh Chari
- Department of Biochemistry, NKP Salve Institute of Medical Science, Nagpur, India
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Bishnoi IR, Ossenkopp KP, Kavaliers M. Sex and age differences in locomotor and anxiety-like behaviors in rats: From adolescence to adulthood. Dev Psychobiol 2020; 63:496-511. [PMID: 33047845 DOI: 10.1002/dev.22037] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/10/2020] [Accepted: 08/27/2020] [Indexed: 12/22/2022]
Abstract
Risk-taking behaviors are a primary contributor to elevated adolescent injury and mortality. Locomotor and anxiety-like behaviors in rodents have been used to examine risk-taking. Here, we examined risk-taking behavior (i.e., changes in locomotor and anxiety-like behaviors) from early to late adolescence and adulthood in male and female rats in the open-field (OF) apparatus and the light-dark (LD) test. We also examined whether these behaviors are affected by an early adolescent immune stressor, lipopolysaccharide (LPS). Long-Evans male and female rats were injected with LPS (200 μg/kg) or vehicle control in early adolescence (postnatal day [PND] 30 and 32). Anxiety-like behavior and locomotor activity were measured in early (PND 38-40), late adolescence (PND 50), and adulthood (PND 88 and 98) in the OF and in early adolescence (PND 42) and adulthood (PND 90) in the LD test. Early and late adolescent rats displayed significantly greater locomotor and anxiety-like behaviors than adult rats in the OF and LD test. Sex differences were also found, with adolescent and adult females displaying greater locomotor and anxiety-like behaviors than male rats in the OF and LD tests. LPS administered two times in early adolescence did not have a significant impact on either locomotor or anxiety-like behaviors suggesting minimal impact of the immune stressor.
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Affiliation(s)
- Indra R Bishnoi
- Graduate Program in Neuroscience, Western University, London, ON, Canada.,Department of Psychology, Western University, London, ON, Canada
| | - Klaus-Peter Ossenkopp
- Graduate Program in Neuroscience, Western University, London, ON, Canada.,Department of Psychology, Western University, London, ON, Canada
| | - Martin Kavaliers
- Graduate Program in Neuroscience, Western University, London, ON, Canada.,Department of Psychology, Western University, London, ON, Canada
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Ma J, Wang X, Lv T, Liu J, Ren Y, Zhang J, Zhang Y. Effects of Ghrelin on the Apoptosis of Rheumatoid Arthritis Fibroblast-Like Synoviocyte MH7A Cells. Biol Pharm Bull 2018; 42:158-163. [PMID: 30429411 DOI: 10.1248/bpb.b18-00285] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin is a circulating peptide hormone, which involved in promoting feeding and regulating energy metabolism in human and rodents. Abnormal synovial hyperplasia is the most important pathologic hallmark of rheumatoid arthritis (RA), which is characterised by tumor-like expansion. Existing studies indicated that there may exist some relation between the decreased ghrelin and the abnormally proliferating synovial cells in RA. Therefore, the aim of this study is to explore the apoptotic effects of ghrelin on MH7A synovial cells in vitro. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the effects of ghrelin on the viability of MH7A cells. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) and flow cytometry were used to test the apoptotic effects of ghrelin. At last, Western blot and real-time PCR were performed to explore the expression of caspases-8, -9, and -3 after the treatment of ghrelin. MTT experiments showed that ghrelin could inhibit viability of MH7A cells. The results of flow cytometry and TUNEL showed that ghrelin could induce apoptosis of MH7A synovial cells. Western blot showed that expression of cleaved-caspases-8, -9, and -3 were increased in ghrelin stimulation group compared with the control group, while expression of pro-caspases-8, -9, and -3 had no significant difference. In mRNA levels, ghrelin can decrease pro-caspases-8, -9, and -3 mRNA expression, which confirmed the results of protein levels. Then these apoptotic effects were significantly reversed by [D-Lys3] GHRP-6 (ghrelin receptor antagonist). This study found that ghrelin can induce apoptosis of MH7A cells through caspase signaling pathways.
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Affiliation(s)
- Junxian Ma
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
| | - Xinbo Wang
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
| | - Tingting Lv
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
| | - Jie Liu
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
| | - Ying Ren
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
| | - Jinshan Zhang
- Department of Human Anatomy and Histology and Embryology, the Fourth Military Medical University (Air Force Medical University)
| | - Yan Zhang
- Department of Rheumatology and Immunology, Tangdu Hospital of the Fourth Military Medical University (Air Force Medical University)
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Alipoor E, Mohammad Hosseinzadeh F, Hosseinzadeh-Attar MJ. Adipokines in critical illness: A review of the evidence and knowledge gaps. Biomed Pharmacother 2018; 108:1739-1750. [PMID: 30372877 DOI: 10.1016/j.biopha.2018.09.165] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
Adipose tissue products or adipokines play a major role in chronic endocrine and metabolic disorders; however, little is known about critical conditions. In this article, the experimental and clinical evidence of alterations of adipokines, adiponectin, leptin, resistin, visfatin, asymmetric dimethylarginine (ADMA), and ghrelin in critical illness, their potential metabolic, diagnostic, and prognostic value, and the gaps in the field have been reviewed. The results showed considerable changes in the concentration of the adipokines; while the impact of adipokines on metabolic disorders such as insulin resistance and inflammation has not been well documented in critically ill patients. There is no consensus about the circulatory and functional changes of leptin and adiponectin. However, it seems that lower concentrations of adiponectin at admission with gradual consequent increase might be a useful pattern in determining better outcomes of critical illness. Some evidence has suggested the adverse effects of elevated resistin concentration, potential prognostic importance of visfatin, and therapeutic value of ghrelin. High ADMA levels and low arginine:ADMA ratio were also proposed as predictors of ICU mortality and morbidities. However, there is no consensus on these findings. Although primary data indicated the role of adipokines in critical illness, further studies are required to clarify whether the reason of these changes is pathophysiological or compensatory. The relationship of pathophysiological background, disease severity, baseline nutritional status and nutrition support during hospitalization, and variations in body fat percentage and distribution with adipokines, as well as the potential prognostic or therapeutic role of these peptides should be further investigated in critically ill patients.
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Affiliation(s)
- Elham Alipoor
- Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran; Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Mohammad Hosseinzadeh
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Javad Hosseinzadeh-Attar
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran; Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia.
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Asadi N, Kheradmand A, Gholami M, Moradi FH. Effect of ghrelin on the biochemical and histopathology parameters and spermatogenesis cycle following experimental varicocele in rat. Andrologia 2018; 50:e13106. [DOI: 10.1111/and.13106] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/21/2018] [Accepted: 06/11/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Nematollah Asadi
- Razi Herbal Medicines Research Center; Lorestan University of Medical Sciences; Khorramabad Iran
- Animal Science Research Institute (ASRI); Jihad-e-Agriculture Ministry; Karaj Iran
| | - Arash Kheradmand
- Department of Clinical Sciences, School of Veterinary Medicine; Lorestan University; Khorramabad Iran
| | | | - Forouzan Hadipour Moradi
- Razi Herbal Medicines Research Center; Lorestan University of Medical Sciences; Khorramabad Iran
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Özkök E, Yorulmaz H, Ateş G, Aydın I, Ergüven M, Tamer Ş. The impact of pretreatment with simvastatin on kidney tissue of rats with acute sepsis. Physiol Int 2017; 104:158-170. [PMID: 28665194 DOI: 10.1556/2060.104.2017.2.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It has been reported that changes in cytokine levels affect mitochondrial functions, levels of hypoxia-inducible factor α (HIF-1α), and tissue damage during sepsis. We aimed to investigate the effects of simvastatin pretreatment on mitochondrial enzyme activities, and on levels of ghrelin, HIF-1α, and thiobarbituric acid reactive substances (TBARS) in kidney tissue during sepsis. Rats were separated into four groups, namely, control, lipopolysaccharides (LPS) (20 mg/kg), simvastatin (20 mg/kg), and simvastatin + LPS. We measured the levels of mitochondrial enzyme activities and TBARS in the kidney using spectrophotometry. The histological structure of the kidney sections was examined after staining with hematoxylin and eosin. Tumor necrosis factor α (TNF-α), IL-10, HIF-1α, and ghrelin immunoreactivity were examined using proper antibodies. In tissue, TNF-α (p < 0.01) and HIF-1α (p < 0.05) levels were increased in the simvastatin + LPS and LPS groups. TBARS levels were higher in the LPS group than in the other groups (p < 0.01), but they were similar in the simvastatin + LPS and control groups (p > 0.05). Ghrelin immunoreactivity was lower in the LPS group (p < 0.05) and higher in the simvastatin + LPS group than in the LPS group (p < 0.01). We observed tubular damage in the sections of the LPS group. There were no differences in mitochondrial enzyme activities between the groups (p > 0.05). We observed that pretreatment of simvastatin caused favorable changes on ghrelin and TBARS levels in rats with sepsis.
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Affiliation(s)
- E Özkök
- 1 Deparment of Neuroscience, The Institute of Experimental Medicine, Istanbul University , Istanbul, Turkey
| | - H Yorulmaz
- 2 Medical Faculty, Haliç University , Istanbul, Turkey
| | - G Ateş
- 3 Department of Physiology, Istanbul Medical Faculty, Istanbul University , Istanbul, Turkey
| | - I Aydın
- 4 Medical Laboratory Techniques Department, Associate's Degree Vocational School, Beykent University , Istanbul, Turkey
| | - M Ergüven
- 5 Faculties of Engineering and Health Sciences, Istanbul Aydın University , Istanbul, Turkey
| | - Ş Tamer
- 3 Department of Physiology, Istanbul Medical Faculty, Istanbul University , Istanbul, Turkey
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Impact of ghrelin on body composition and muscle function in a long-term rodent model of critical illness. PLoS One 2017; 12:e0182659. [PMID: 28796827 PMCID: PMC5552127 DOI: 10.1371/journal.pone.0182659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 07/22/2017] [Indexed: 01/14/2023] Open
Abstract
Background Patients with multiple injuries or sepsis requiring intensive care treatment invariably develop a catabolic state with resultant loss of lean body mass, for which there are currently no effective treatments. Recovery can take months and mortality is high. We hypothesise that treatment with the orexigenic and anti-inflammatory gastric hormone, ghrelin may attenuate the loss of body mass following critical illness and improve recovery. Methods Male Wistar rats received an intraperitoneal injection of the fungal cell wall derivative zymosan to induce a prolonged peritonitis and consequent critical illness. Commencing at 48h after zymosan, animals were randomised to receive a continuous infusion of ghrelin or vehicle control using a pre-implanted subcutaneous osmotic mini-pump, and continued for 10 days. Results Zymosan peritonitis induced significant weight loss and reduced food intake with a nadir at Day 2 and gradual recovery thereafter. Supra-physiologic plasma ghrelin levels were achieved in the treated animals. Ghrelin-treated rats ate more food and gained more body mass than controls. Ghrelin increased adiposity and promoted carbohydrate over fat metabolism, but did not alter total body protein, muscle strength nor muscle morphology. Muscle mass and strength remained significantly reduced in all zymosan-treated animals, even at ten days post-insult. Conclusions Continuous infusion of ghrelin increased body mass and food intake, but did not increase muscle mass nor improve muscle function, in a long-term critical illness recovery model. Further studies with pulsatile ghrelin delivery or additional anabolic stimuli may further clarify the utility of ghrelin in survivors of critical illness.
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Rivas PMS, Vechiato FMV, Borges BC, Rorato R, Antunes-Rodrigues J, Elias LLK. Increase in hypothalamic AMPK phosphorylation induced by prolonged exposure to LPS involves ghrelin and CB1R signaling. Horm Behav 2017; 93:166-174. [PMID: 28576646 DOI: 10.1016/j.yhbeh.2017.05.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 05/15/2017] [Accepted: 05/28/2017] [Indexed: 12/29/2022]
Abstract
Acute administration of lipopolysaccharide (LPS) from Gram-negative bacteria induces hypophagia. However, the repeated administration of LPS leads to desensitization of hypophagia, which is associated with increased hypothalamic p-AMPK expression. Because ghrelin and endocannabinoids modulate AMPK activity in the hypothalamus, we hypothesized that these neuromodulators play a role in the reversal of tolerance to hypophagia in rats under long-term exposure to LPS. Male Wistar rats were treated with single (1 LPS, 100μg/kg body weight, ip) or repeated injections of LPS over 6days (6 LPS). Food intake was reduced in the 1 LPS, but not in the 6 LPS group. 6 LPS rats showed an increased serum concentration of acylated ghrelin and reduced ghrelin receptor mRNA expression in the hypothalamus. Ghrelin injection (40μg/kg body weight, ip) increased food intake, body weight gain, p-AMPK hypothalamic expression, neuropeptide Y (NPY) and Agouti related peptide (AgRP) mRNA expression in control animals (Saline). However, in 6 LPS rats, ghrelin did not alter these parameters. Central administration of a CB1R antagonist (AM251, 200ng/μl in 5μl/rat) induced hypophagia in 6 LPS animals, suggesting that the endocannabinoid system contributes to preserved food intake during LPS tolerance. In the presence of AM251, the ability of ghrelin to phosphorylate AMPK in the hypothalamus of 6 LPS group was restored, but not its orexigenic effect. Our data highlight that the orexigenic effects of ghrelin require CB1R signaling downstream of AMPK activation. Moreover, CB1R-mediated pathways contribute to the absence of hypophagia during repeated exposure to endotoxin.
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Affiliation(s)
- Priscila M S Rivas
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Fernanda M V Vechiato
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Beatriz C Borges
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Rodrigo Rorato
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Jose Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Lucila L K Elias
- Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil.
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Bando M, Iwakura H, Ueda Y, Ariyasu H, Inaba H, Furukawa Y, Furuta H, Nishi M, Akamizu T. IL-1β directly suppress ghrelin mRNA expression in ghrelin-producing cells. Mol Cell Endocrinol 2017; 447:45-51. [PMID: 28237719 DOI: 10.1016/j.mce.2017.02.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/20/2017] [Accepted: 02/20/2017] [Indexed: 02/05/2023]
Abstract
In animal models, ghrelin production is suppressed by LPS administration. To elucidate the detailed molecular mechanisms involved in the phenomenon, we investigated the effects of LPS and LPS-inducible cytokines, including TNF-α, IL-1β, and IL-6, on the expression of ghrelin in the ghrelin-producing cell line MGN3-1. These cells expressed IL-1R, and IL-1β significantly suppressed ghrelin mRNA levels. The suppressive effects of IL-1β were attenuated by knockdown of IKKβ, suggesting the involvement of the NF-κB pathway. These results suggested that IL-1β is a major regulator of ghrelin expression during inflammatory processes.
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Affiliation(s)
- Mika Bando
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Hiroshi Iwakura
- The First Department of Medicine, Wakayama Medical University, Japan.
| | - Yoko Ueda
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Hiroyuki Ariyasu
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Hidefumi Inaba
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Yasushi Furukawa
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Hiroto Furuta
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Masahiro Nishi
- The First Department of Medicine, Wakayama Medical University, Japan
| | - Takashi Akamizu
- The First Department of Medicine, Wakayama Medical University, Japan
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Abstract
In the current study, we examined the effects of LPS and inflammatory cytokines including IL-1β, TNF-α, and IL-6 on the expression of ghrelin in MGN3-1 cells. We found that IL-1β, and TNF-α with lesser extent, significantly suppressed ghrelin mRNA expression in the cells. MGN3-1 cells expressed IL-1β receptor and IL-1β significantly stimulated NF-κB, p38, JNK, and ERK pathways. Knockdown of IKK2 by siRNA significantly attenuated the suppression of ghrelin mRNA by IL-1β. These results indicate that IL-1β directly suppressed ghrelin mRNA via NF-κB pathway at least partially, which may have a role in the regulation of appetite during inflammation.
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Affiliation(s)
- Hiroshi Iwakura
- The First Department of Medicine, Wakayama Medical University, Wakayama 841-8509, Japan
| | - Mika Bando
- The First Department of Medicine, Wakayama Medical University, Wakayama 841-8509, Japan
| | - Yoko Ueda
- The First Department of Medicine, Wakayama Medical University, Wakayama 841-8509, Japan
| | - Takashi Akamizu
- The First Department of Medicine, Wakayama Medical University, Wakayama 841-8509, Japan
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Makkar SK, Rath NC, Packialakshmi B, Zhou ZY, Huff GR, Donoghue AM. Nutritional Supplement of Hatchery Eggshell Membrane Improves Poultry Performance and Provides Resistance against Endotoxin Stress. PLoS One 2016; 11:e0159433. [PMID: 27463239 PMCID: PMC4963089 DOI: 10.1371/journal.pone.0159433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/01/2016] [Indexed: 12/02/2022] Open
Abstract
Eggshells are significant part of hatchery waste which consist of calcium carbonate crust, membranes, and proteins and peptides of embryonic origins along with other entrapped contaminants including microbes. We hypothesized that using this product as a nutritional additive in poultry diet may confer better immunity to the chickens in the paradigm of mammalian milk that enhances immunity. Therefore, we investigated the effect of hatchery eggshell membranes (HESM) as a short term feed supplement on growth performance and immunity of chickens under bacterial lipopolysaccharide (LPS) challenged condition. Three studies were conducted to find the effect of HESM supplement on post hatch chickens. In the first study, the chickens were fed either a control diet or diets containing 0.5% whey protein or HESM as supplement and evaluated at 5 weeks of age using growth, hematology, clinical chemistry, plasma immunoglobulins, and corticosterone as variables. The second and third studies were done to compare the effects of LPS on control and HESM fed birds at 5 weeks of age following at 4 and 24 h of treatment where the HESM was also sterilized with ethanol to deplete bacterial factors. HESM supplement caused weight gain in 2 experiments and decreased blood corticosterone concentrations. While LPS caused a significant loss in body weight at 24 h following its administration, the HESM supplemented birds showed significantly less body weight loss compared with the control fed birds. The WBC, heterophil/lymphocyte ratio, and the levels of IgG were low in chickens fed diets with HESM supplement compared with control diet group. LPS challenge increased the expression of pro-inflammatory cytokine gene IL-6 but the HESM fed birds showed its effect curtailed, also, which also, favored the up-regulation of anti-inflammatory genes compared with control diet fed chickens. Post hatch supplementation of HESM appears to improve performance, modulate immunity, and increase resistance of chickens to endotoxin.
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Affiliation(s)
- S. K. Makkar
- Poultry Production & Product Safety Research Unit, Agricultural Research Service, USDA, Fayetteville, Arkansas, United States of America
- Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, United States of America
| | - N. C. Rath
- Poultry Production & Product Safety Research Unit, Agricultural Research Service, USDA, Fayetteville, Arkansas, United States of America
- * E-mail:
| | - B. Packialakshmi
- Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, United States of America
| | - Z. Y. Zhou
- Department of Veterinary Medicine, Rongchang campus of Southwest University, Rongchang County, China
| | - G. R. Huff
- Poultry Production & Product Safety Research Unit, Agricultural Research Service, USDA, Fayetteville, Arkansas, United States of America
| | - A. M. Donoghue
- Poultry Production & Product Safety Research Unit, Agricultural Research Service, USDA, Fayetteville, Arkansas, United States of America
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Lin L, Lee JH, Buras ED, Yu K, Wang R, Smith CW, Wu H, Sheikh-Hamad D, Sun Y. Ghrelin receptor regulates adipose tissue inflammation in aging. Aging (Albany NY) 2016; 8:178-91. [PMID: 26837433 PMCID: PMC4761721 DOI: 10.18632/aging.100888] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 01/20/2016] [Indexed: 12/30/2022]
Abstract
Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), increases in adipose tissues during aging, and old Ghsr(-/-) mice exhibit a lean and insulin-sensitive phenotype. Macrophages are major mediators of adipose tissue inflammation, which consist of pro-inflammatory M1 and anti-inflammatory M2 subtypes. Here, we show that in aged mice, GHS-R ablation promotes macrophage phenotypical shift toward anti-inflammatory M2. Old Ghsrp(-/-) mice have reduced macrophage infiltration, M1/M2 ratio, and pro-inflammatory cytokine expression in white and brown adipose tissues. We also found that peritoneal macrophages of old Ghsrp(-/-) mice produce higher norepinephrine, which is in line with increased alternatively-activated M2 macrophages. Our data further reveal that GHS-R has cell-autonomous effects in macrophages, and GHS-R antagonist suppresses lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Collectively, our studies demonstrate that ghrelin signaling has an important role in macrophage polarization and adipose tissue inflammation during aging. GHS-R antagonists may serve as a novel and effective therapeutic option for age-associated adipose tissue inflammation and insulin resistance.
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Affiliation(s)
- Ligen Lin
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Jong Han Lee
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Eric D. Buras
- Department of Internal Medicine at University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Kaijiang Yu
- Department of Intensive Care Unit, the Third Affiliated Hospital, Harbin Medical University, Harbin, 150081, China
| | - Ruitao Wang
- Department of Intensive Care Unit, the Third Affiliated Hospital, Harbin Medical University, Harbin, 150081, China
| | - C. Wayne Smith
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Huaizhu Wu
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Sheikh-Hamad
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuxiang Sun
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX 77843, USA
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Novel Antioxidant Properties of Ghrelin and Oleuropein Versus Lipopolysaccharide-Mediated Renal Failure in Rats. Int J Pept Res Ther 2015. [DOI: 10.1007/s10989-015-9470-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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A New Strategy Using Rikkunshito to Treat Anorexia and Gastrointestinal Dysfunction. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:364260. [PMID: 26064162 PMCID: PMC4433667 DOI: 10.1155/2015/364260] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 09/26/2014] [Accepted: 10/07/2014] [Indexed: 12/13/2022]
Abstract
Because the clinical condition of gastrointestinal dysfunction, including functional dyspepsia, involves tangled combinations of pathologies, there are some cases of insufficient curative efficacy. Thus, traditional herbal medicines (Kampo medicines) uniquely developed in Japan are thought to contribute to medical treatment for upper gastrointestinal symptoms. Rikkunshito is a Kampo medicine often used to treat dyspeptic symptoms. Over the past few years, several studies have investigated the efficacy of rikkunshito for dysmotility, for example, upper abdominal complaints, in animals and humans. Rikkunshito ameliorated the decrease in gastric motility and anorexia in cisplatin-treated rats, stress-loaded mice, and selective serotonin reuptake inhibitor-treated rats by enhancing plasma ghrelin levels via serotonin2B/2C receptor antagonism. In addition, rikkunshito ameliorated the decrease in food intake in aged mice and stress-loaded decreased gastric motility via enhanced ghrelin receptor signaling. Several clinical studies revealed that rikkunshito was effective in ameliorating upper gastrointestinal symptoms, including dyspepsia, epigastric pain, and postprandial fullness. In this review, we discuss these studies and propose additional evidence-based research that may promote the clinical use of Kampo medicines, particularly rikkunshito, for treating anorexia and gastrointestinal dysfunction.
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Shiimura Y, Ohgusu H, Sato T, Kojima M. Regulation of the Human Ghrelin Promoter Activity by Transcription Factors, NF-κB and Nkx2.2. Int J Endocrinol 2015; 2015:580908. [PMID: 25699080 PMCID: PMC4324914 DOI: 10.1155/2015/580908] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/24/2014] [Indexed: 11/24/2022] Open
Abstract
To examine the gene expression of ghrelin, a growth hormone releasing and appetite stimulating hormone from stomach, we constructed human ghrelin promoter-reporter vectors and analyzed the promoter activity. The ghrelin promoter activity was high when cultured cells that express ghrelin mRNA endogenously like TT or ECC10 cells were used, indicating that these cells contain factors necessary for full expression of the human ghrelin gene. The human ghrelin promoter contains both positive and negative regulatory regions. A transient decrease of the promoter activity was found when the reporter vector with the -1600 fragment of the human ghrelin promoter was transfected into cultured cells. We then examined the effect of several transcription factors on the ghrelin promoter activity and found that NF-κB suppressed and that Nkx2.2, a homeodomain-containing transcription factor that is important for ghrelin cell development in pancreas, activates the promoter activity. These transcription factors may be possible targets for the control of ghrelin gene expression.
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Affiliation(s)
- Yuki Shiimura
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 839-0864, Japan
| | - Hideko Ohgusu
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 839-0864, Japan
| | - Takahiro Sato
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 839-0864, Japan
| | - Masayasu Kojima
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka 839-0864, Japan
- *Masayasu Kojima:
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Szentirmai É, Krueger JM. Sickness behaviour after lipopolysaccharide treatment in ghrelin deficient mice. Brain Behav Immun 2014; 36:200-6. [PMID: 24309634 PMCID: PMC3951816 DOI: 10.1016/j.bbi.2013.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/04/2013] [Accepted: 11/26/2013] [Indexed: 12/14/2022] Open
Abstract
Ghrelin is an orexigenic hormone produced mainly by the gastrointestinal system and the brain. Much evidence also indicates a role for ghrelin in sleep and thermoregulation. Further, ghrelin was recently implicated in immune system modulation. Administration of bacterial lipopolysaccharide (LPS) induces fever, anorexia, and increased non-rapid-eye movement sleep (NREMS) and these actions are mediated primarily by proinflammatory cytokines. Ghrelin reduces LPS-induced fever, suppresses circulating levels of proinflammatory cytokines and reduces the severity and mortality of various models of experimental endotoxemia. In the present study, we determined the role of intact ghrelin signaling in LPS-induced sleep, feeding, and thermoregulatory responses in mice. Sleep-wake activity was determined after intraperitoneal, dark onset administration of 0.4, 2 and 10 μg LPS in preproghrelin knockout (KO) and wild-type (WT) mice. In addition, body temperature, motor activity and changes in 24-h food intake and body weight were measured. LPS induced dose-dependent increases in NREMS, and suppressed rapid-eye movement sleep, electroencephalographic slow-wave activity, motor activity, food intake and body weight in both Ppg KO and WT mice. Body temperature changes showed a biphasic pattern with a decrease during the dark period followed by an increase in the light phase. The effects of the low and middle doses of LPS were indistinguishable between the two genotypes. Administration of 10 μg LPS, however, induced significantly larger changes in NREMS and wakefulness amounts, body temperature, food intake and body weight in the Ppg KO mice. These findings support a role for ghrelin as an endogenous modulator of inflammatory responses and a central component of arousal and feeding circuits.
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Affiliation(s)
- Éva Szentirmai
- Washington, Wyoming, Alaska, Montana and Idaho (WWAMI) Medical Education Program, Washington State University, Spokane, WA, USA; Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA; Sleep and Performance Research Center, Washington State University, Spokane, WA, USA.
| | - James M. Krueger
- Washington, Wyoming, Alaska, Montana and Idaho (WWAMI)
Medical Education Program, Washington State University, Spokane, WA, USA,Department of Integrative Physiology and Neuroscience,
Washington State University, Spokane, WA, USA,Sleep and Performance Research Center, Washington State
University, Spokane, WA, USA
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18
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Ghrelin receptor regulates HFCS-induced adipose inflammation and insulin resistance. Nutr Diabetes 2013; 3:e99. [PMID: 24366371 PMCID: PMC3877431 DOI: 10.1038/nutd.2013.41] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 11/26/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND OBJECTIVES High fructose corn syrup (HFCS) is the most commonly used sweetener in the United States. Some studies show that HFCS consumption correlates with obesity and insulin resistance, while other studies are in disagreement. Owing to conflicting and insufficient scientific evidence, the safety of HFCS consumption remains controversial. SUBJECTS/METHODS We investigated the metabolic consequences of mice fed a (a) regular diet, (b) 'Western' high-fat diet or (c) regular diet supplemented with 8% HFCS in drinking water (to mimic soft drinks) for 10 months. Adipose tissue macrophages (ATMs) have emerged as a major pathogenic factor for obesity and insulin resistance. ATMs consist of proinflammatory F4/80(+)CD11c(+) macrophages and anti-inflammatory F4/80(+)CD11c(-) macrophages. In this study, we assessed the effects of HFCS on ATMs in intra-abdominal fat. RESULTS We found that HFCS feeding in mice induced more severe adipose inflammation and insulin resistance than even the higher-calorie-containing 'Western' high-fat diet, and these HFCS-induced deleterious effects were independent of calorie intake or body fat content. We showed that similar to 'Western' high-fat diet, HFCS triggered a robust increase of both proinflammatory ATMs and anti-inflammatory ATMs in intra-abdominal fat. Remarkably, however, the anti-inflammatory ATMs were much less abundant in HFCS-fed mice than in high-fat-fed mice. Furthermore, we showed that deletion of the ghrelin receptor (growth hormone secretagogue receptor, GHS-R) ameliorates HFCS-induced adipose inflammation and insulin resistance. HFCS-fed GHS-R-null mice exhibit decreased proinflammatory ATMs in intra-abdominal fat, reduced adipose inflammation and attenuated liver steatosis. CONCLUSION Our studies demonstrate that HFCS has detrimental effects on metabolism, suggesting that dietary guidelines on HFCS consumption for Americans may need to be revisited. GHS-R deletion mitigates the effects of HFCS on adipose inflammation and insulin resistance, suggesting that GHS-R antagonists may represent a novel therapy for insulin resistance.
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Gómez-SanMiguel AB, Martín AI, Nieto-Bona MP, Fernández-Galaz C, López-Menduiña M, Villanúa MÁ, López-Calderón A. Systemic α-melanocyte-stimulating hormone administration decreases arthritis-induced anorexia and muscle wasting. Am J Physiol Regul Integr Comp Physiol 2013; 304:R877-86. [PMID: 23515620 DOI: 10.1152/ajpregu.00447.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Rheumatoid cachexia is associated with rheumatoid arthritis and it increases mortality and morbidity. Adjuvant-induced arthritis is an experimental model of rheumatoid arthritis that causes anorexia and muscle wasting. α-Melanocyte-stimulating hormone (α-MSH) has anti-inflammatory actions, and it is able to decrease inflammation in several inflammatory diseases including experimental arthritis. In this study we tested whether systemic α-MSH treatment is able to ameliorate cachexia in arthritic rats. On day 8 after adjuvant injection control and arthritic rats were treated with α-MSH (50 μg/rat ip) twice a day, until day 16 when all rats were euthanized. Arthritis decreased food intake, but it increased hypothalamic expression of neuropeptide Y (NPY) and Agouti-related peptides (AgRP) as well as interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) mRNA. In arthritic rats, α-MSH decreased the external signs of arthritis and increased food intake (P < 0.01). In addition, α-MSH decreased hypothalamic expression of IL-1β, COX-2, proopiomelanocortin, and prohormone-converting (PC) enzymes PC1/3 and PC2 mRNA in arthritic rats. In control rats, α-MSH did not modify food intake or hypothalamic expression of aforementioned mRNA. α-MSH prevented arthritis-induced increase in gastrocnemius COX-2, muscle-specific RING-finger protein-1 (MuRF1), and atrogin-1 expression, and it increased fast myofiber size. In conclusion our data show that in arthritic rats peripheral α-MSH treatment has an anti-cachectic action increasing food intake and decreasing muscle wasting.
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20
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Yılmaz G, Kırzıoğlu FY, Doğuç DK, Koçak H, Orhan H. Ghrelin levels in chronic periodontitis patients. Odontology 2013; 102:59-67. [DOI: 10.1007/s10266-012-0100-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 12/05/2012] [Indexed: 12/20/2022]
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21
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Borner T, Pinkernell S, Lutz TA, Riediger T. Lipopolysaccharide inhibits ghrelin-excited neurons of the arcuate nucleus and reduces food intake via central nitric oxide signaling. Brain Behav Immun 2012; 26:867-79. [PMID: 22465682 DOI: 10.1016/j.bbi.2012.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/14/2012] [Accepted: 03/19/2012] [Indexed: 12/30/2022] Open
Abstract
Lipopolysaccharide (LPS) induces anorexia and expression of inducible nitric oxide synthase (iNOS) in the hypothalamic arcuate nucleus (Arc). Peripheral administration of the iNOS inhibitor 1400 W counteracts the anorectic effects of LPS. Here we investigated the role of central NO signaling in LPS anorexia. In electrophysiological studies we tested whether 1400 W counteracts the iNOS-dependent inhibition of Arc neurons triggered by in vivo or in vitro stimulation with LPS. We used the hormone ghrelin as a functional reference stimulus because ghrelin is known to activate orexigenic Arc neurons. Further, we investigated whether in vitro LPS stimulation induces an iNOS-mediated formation of the second messenger cGMP. Since the STAT1 pathway contributes to the regulation of iNOS expression we investigated whether LPS treatment induces STAT1 phosphorylation in the Arc. Finally we tested the effect of intracerebroventricular injection of 1400 W on LPS-induced anorexia. Superfusion with 1400 W (10(-4) M) increased neuronal activity in 37% of neurons in Arc slices from LPS treated (100 μg/kg ip) but not from saline treated rats. Similarly, 1400 W excited 45% of Arc neurons after in vitro stimulation with LPS (100 ng/ml). In both approaches, a considerable percentage of 1400 W sensitive neurons were excited by ghrelin (10(-8)M; 50% and 75%, respectively). In vitro stimulation with LPS induced cGMP formation in the Arc, which was blocked by co-incubation with 1400 W. LPS treatment elicited a pSTAT1 response in the Arc of mice. Central 1400 W injection (4 μg/rat) attenuated LPS-induced anorexia and counteracted the LPS-dependent decrease in respiratory quotient and energy expenditure. In conclusion, the current findings substantiate a role of central iNOS dependent NO formation in LPS-induced effects on eating and energy homeostasis. A pharmacological blockade of NO formation might be a therapeutic approach to ameliorate disease-related anorexia.
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Affiliation(s)
- Tito Borner
- Institute of Veterinary Physiology and Centre of Integrative Human Physiology, University of Zurich, 8057 Zurich, Switzerland
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22
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Abstract
PURPOSE OF REVIEW Recovery and rehabilitation after critical illness is a vital part of intensive care management. The role of feeding and nutritional intervention is the subject of many recent studies. The gastric hormone ghrelin has effects on appetite and food intake and on immunomodulatory functions. Here we review the interactions between critical illness, appetite regulation, nutrition and ghrelin. RECENT FINDINGS Critical illness results in significant loss of lean body mass; strategies to prevent this have so far proven unsuccessful. Ghrelin has been shown to reduce catabolic protein loss in animal models of critical illness and improve body composition in chronic cachectic illnesses in humans. SUMMARY Enhancing recovery from critical illness will improve both short-term and long-term outcomes. Ghrelin may offer an important means of improving appetite, muscle mass and rehabilitation in the period after critical illness, although studies are needed to see whether this potential is realized.
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Stengel A, Taché Y. Ghrelin - a pleiotropic hormone secreted from endocrine x/a-like cells of the stomach. Front Neurosci 2012; 6:24. [PMID: 22355282 PMCID: PMC3280431 DOI: 10.3389/fnins.2012.00024] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Accepted: 01/29/2012] [Indexed: 12/13/2022] Open
Abstract
The gastric X/A-like endocrine cell receives growing attention due to its peptide products with ghrelin being the best characterized. This peptide hormone was identified a decade ago as a stimulator of food intake and to date remains the only known peripherally produced and centrally acting orexigenic hormone. In addition, subsequent studies identified numerous other functions of this peptide including the stimulation of gastrointestinal motility, the maintenance of energy homeostasis and an impact on reproduction. Moreover, ghrelin is also involved in the response to stress and assumed to play a role in coping functions and exert a modulatory action on immune pathways. Our knowledge on the regulation of ghrelin has markedly advanced during the past years by the identification of the ghrelin acylating enzyme, ghrelin-O-acyltransferase, and by the description of changes in expression, activation, and release under different metabolic as well as physically and psychically challenging conditions. However, our insight on regulatory processes of ghrelin at the cellular and subcellular levels is still very limited and warrants further investigation.
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Affiliation(s)
- Andreas Stengel
- Division Psychosomatic Medicine and Psychotherapy, Department of Medicine, Charité - Universitätsmedizin Berlin Berlin, Germany
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Satou M, Nakamura Y, Ando H, Sugimoto H. Understanding the functional significance of ghrelin processing and degradation. Peptides 2011; 32:2183-90. [PMID: 21763742 DOI: 10.1016/j.peptides.2011.06.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 06/08/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
Post-translational modification, cleavage and processing of circulating hormones are common themes in the control of hormone activities. Full-length ghrelin is a 28 amino acid protein that exists in several modified and processed forms, including addition of an acyl moiety at the third serine of the N-terminus. When modified with octanoic acid, the first five N-terminal residues of ghrelin can modulate a signaling pathway via the ghrelin receptor GHSR1a. Although modification via a lipid moiety is essential for binding and activation of GHSR1a by ghrelin, many reports suggest that a desacyl form of ghrelin exists and has synergistic, opposing and distinct properties as compared to the acyl form. Therefore, it is important to clarify the physiological relevance of ghrelin derivatives. Based on lines of evidence from various studies, we propose that a larger proportion of secreted ghrelin is present in the deacylated form and furthermore, that circulating acyl and desacyl forms of ghrelin may be hydrolyzed to form short peptide fragments. Here, we summarize the results of studies aimed at understanding ghrelin processing and its implications for physiological function, as well as our recent findings regarding enzymes in the blood capable of generating processed forms of ghrelin.
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Affiliation(s)
- Motoyasu Satou
- Departments of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
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25
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Stengel A, Wang L, Taché Y. Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications. Peptides 2011; 32:2208-17. [PMID: 21782868 PMCID: PMC3220774 DOI: 10.1016/j.peptides.2011.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 07/04/2011] [Accepted: 07/05/2011] [Indexed: 12/11/2022]
Abstract
Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, acute fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress.
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Affiliation(s)
- Andreas Stengel
- CURE: Digestive Diseases Research Center, David Geffen School of Medicine, University of California Los Angeles and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, United States.
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Baatar D, Patel K, Taub DD. The effects of ghrelin on inflammation and the immune system. Mol Cell Endocrinol 2011; 340:44-58. [PMID: 21565248 DOI: 10.1016/j.mce.2011.04.019] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/15/2011] [Accepted: 04/22/2011] [Indexed: 12/25/2022]
Abstract
A number of hormones and metabolic mediators signal the brain of changes in the body's energy status and when an imbalance occurs; the brain coordinates the appropriate changes in energy intake and utilization via the control of appetite and food consumption. Under conditions of chronic inflammation and immune activation, there is often a significant loss of body mass and appetite suggesting the presence of shared ligands and signaling pathways mediating "crosstalk" between the immune and neuroendocrine systems. Ghrelin, the endogenous ligand for growth hormone secretagogue receptor (GHS-R), is produced primarily by cells in the stomach and serves as a potent circulating orexigenic hormone controlling food intake, energy expenditure, adiposity and GH secretion. The functional roles of ghrelin and other growth hormone secretagogues (GHS) within the immune system and under states of inflammatory stress and injury are only now coming to light. A number of reports over the past decade have described ghrelin to be a potent anti-inflammatory mediator both in vitro and in vivo and a promising therapeutic agent in the treatment of inflammatory diseases and injury. Moreover, ghrelin has also been shown to promote lymphocyte development in the primary lymphoid organs (bone marrow and thymus) and to ablate age-associated thymic involution. In the current report, we review the literature supporting a role for ghrelin as an anti-inflammatory agent and immunoregulatory hormone/cytokine and its potential use in the treatment of inflammatory diseases and injury.
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Affiliation(s)
- Dolgor Baatar
- Laboratory of Molecular Biology and Immunology, NIA-IRP, NIH, Biomedical Research Center, Baltimore, MD 21224, USA
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Abstract
PURPOSE OF REVIEW Cachexia occurs in various inflammatory diseases and is characterized by weight loss and muscle wasting. Pro-inflammatory cytokines modulate the activity of neuropeptides and hormones that control energy homeostasis and/or illness behaviors. This review summarizes recent (published within the past 18 months) literature regarding neuropeptides and hormones that have been implicated in the pathophysiology of cachexia, and that are likely to have therapeutic potential for preventing or reversing cachexia in various disease states. RECENT FINDINGS Hypothalamic pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons are downstream targets for pro-inflammatory cytokines. Genetic or pharmacological blockade of melanocortin receptor signaling preserves lean body mass and attenuates anorexia in experimental models of cachexia. Orally available melanocortin receptor antagonists have been developed and tested in cachectic animals with favorable results. Ghrelin and ghrelin mimetics increase appetite and preserve lean body mass in cachectic patients with diverse underlying diseases. Additional neuropeptide-expressing neurons in the hypothalamus (e.g., orexin neurons) might play a role in cachexia-associated lethargy. SUMMARY Promising outcomes from recent preclinical studies and/or early clinical trials with melanocortin receptor antagonists and ghrelin mimetics raise hopes that safe and effective anti-cachexia drugs will soon become available for widespread clinical use.
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28
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Souza-Moreira L, Campos-Salinas J, Caro M, Gonzalez-Rey E. Neuropeptides as pleiotropic modulators of the immune response. Neuroendocrinology 2011; 94:89-100. [PMID: 21734355 DOI: 10.1159/000328636] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 04/17/2011] [Indexed: 01/14/2023]
Abstract
Although necessary to eliminate pathogens, inflammation can lead to serious deleterious effects in the host if left unchecked. During the inflammatory response, further damage may arise from potential autoimmune responses occurring when the immune cells and molecules that respond to pathogen-derived antigens also react to self-antigens. In this sense, the identification of endogenous factors that control exacerbated immune responses is a key goal for the development of new therapeutic approaches for inflammatory and autoimmune diseases. Some neuropeptides that are produced during the ongoing inflammatory response have emerged as endogenous anti-inflammatory agents that could collaborate in tuning the balanced steady state of the immune system. These neuropeptides participate in maintaining immune tolerance through two distinct mechanisms: by regulating the balance between pro-inflammatory and anti-inflammatory factors, and by inducing the emergence of regulatory T cells with suppressive activity against autoreactive T cell effectors. Indeed, a functioning neuropeptide system contributes to general health, and alterations in the levels of these neuropeptides and/or their receptors lead to changes in susceptibility to inflammatory and autoimmune diseases. Recently, we found that some neuropeptides also have antimicrobial and antiparasitic actions, suggesting that they could act as primary mediators of innate defense, even in the most primitive organisms. In this review, we use the vasoactive intestinal peptide as example of an immunomodulatory neuropeptide to summarize the most relevant data found for other neuropeptides with similar characteristics, including adrenomedullin, urocortin, cortistatin and ghrelin.
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Affiliation(s)
- Luciana Souza-Moreira
- Instituto de Parasitologia y Biomedicina Lopez-Neyra, Consejo Superior de Investigaciones Cientificas, Granada, Spain
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Satou M, Nishi Y, Yoh J, Hattori Y, Sugimoto H. Identification and characterization of acyl-protein thioesterase 1/lysophospholipase I as a ghrelin deacylation/lysophospholipid hydrolyzing enzyme in fetal bovine serum and conditioned medium. Endocrinology 2010; 151:4765-75. [PMID: 20685872 DOI: 10.1210/en.2010-0412] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ghrelin contains an octanoic acid at the third residue serine, and the presence of octanoic acid on ghrelin is critical to its physiological functions. The precise mechanism for the deacylation of ghrelin in circulation remains to be clarified, although the level of deacylated ghrelin (des-acyl ghrelin) is higher than that of acylated ghrelin in serum. In this study, rapid identification of ghrelin deacylation activity was achieved by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and a ghrelin deacylation enzyme was purified 1515-fold from fetal bovine serum. Chromatographic separation showed a 24-kDa band on SDS-PAGE corresponding to ghrelin deacylation activity, and the protein band was identified as acyl-protein thioesterase 1 (APT1)/lysophospholipase I. A ghrelin deacylation enzyme in medium from HepG2 cells was also purified and identified as APT1. Although it lacks a secretion signal sequence, APT1 may be released by cells expressing APT1, mainly from liver in vivo. APT1 was originally purified as a cytosolic lysophospholipid hydrolyzing enzyme (lysophospholipase I), and recombinant APT1 exhibited deacylation activity as well as lysophospholipase activity in vitro. APT1 is released at high levels from RAW264.7 macrophage-like cells into the culture medium after stimulation with lipopolysaccharide (LPS), and LPS suppresses APT1 mRNA and protein expressions in these cells. More potent ghrelin deacylase activities were detected in sera from LPS-treated rats than in control sera. These results suggested that the serum activity of APT1 may play an important role in determination of the concentration of des-acyl ghrelin in circulation, especially under septic inflammation.
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Affiliation(s)
- Motoyasu Satou
- Department of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
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Stengel A, Goebel M, Wang L, Reeve JR, Taché Y, Lambrecht NW. Lipopolysaccharide differentially decreases plasma acyl and desacyl ghrelin levels in rats: potential role of the circulating ghrelin-acylating enzyme GOAT. Peptides 2010; 31:1689-96. [PMID: 20599577 PMCID: PMC4067316 DOI: 10.1016/j.peptides.2010.06.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Revised: 06/17/2010] [Accepted: 06/17/2010] [Indexed: 12/11/2022]
Abstract
Bacterial lipopolysaccharide (LPS) in rodents is an established model for studying innate immune responses to gram-negative bacteria and mimicking symptoms of infections including reduced food intake associated with decreased circulating total ghrelin levels. The ghrelin-acylating enzyme, ghrelin-O-acyltransferase (GOAT) involved in the formation of acyl ghrelin (AG) was recently identified. We investigated changes in circulating AG, desacyl ghrelin (DG) and GOAT induced by intraperitoneal LPS (100 microg/kg) and associated changes in food intake. Plasma AG and total ghrelin were assessed by radioimmunoassay, GOAT protein by Western blot and mRNA by RT-qPCR. DG was derived from total minus AG. Plasma AG and DG were decreased at 2, 5 and 7 h (p<0.01) post-injection compared to vehicle and recovered at 24 h. At 2 h there was a significantly greater decrease of AG (-53%) than DG (-28%) resulting in a decreased AG/DG ratio (1:5, p<0.01), which thereafter returned to pre-injection values (1:3). This altered ratio was associated with a 38% decrease in plasma GOAT protein compared to vehicle (p<0.001), whereas gastric GOAT protein was slightly increased by 10% (p<0.05). GOAT mRNA expression was unchanged. Food intake was reduced by 58% measured during the 1.5-2 h period post-LPS injection. Decreased plasma AG and DG preceded the rise in rectal temperature and blood glucose that peaked at 7 h. These data indicate that LPS induces a long-lasting reduction of AG and DG levels that may have a bearing with the decrease in food intake. The faster drop in AG than DG within 2 h is associated with reduced circulating GOAT.
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Affiliation(s)
- Andreas Stengel
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - Miriam Goebel
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - Lixin Wang
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - Joseph R. Reeve
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - Yvette Taché
- CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA
| | - Nils W.G. Lambrecht
- Gastrointestinal Endocrinology, Veterans Affairs Long Beach Healthcare System, Long Beach, CA 90822, USA
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Rejuvenation of the aging thymus: growth hormone-mediated and ghrelin-mediated signaling pathways. Curr Opin Pharmacol 2010; 10:408-24. [PMID: 20595009 DOI: 10.1016/j.coph.2010.04.015] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 12/20/2022]
Abstract
One of the major fundamental causes for the aging of the immune system is the structural and functional involution of the thymus, and the associated decline in de novo naïve T-lymphocyte output. This loss of naïve T-cell production weakens the ability of the adaptive immune system to respond to new antigenic stimuli and eventually leads to a peripheral T-cell bias to the memory phenotype. While the precise mechanisms responsible for age-associated thymic involution remain unknown, a variety of theories have been forwarded including the loss of expression of various growth factors and hormones that influence the lymphoid compartment and promote thymic function. Extensive studies examining two hormones, namely growth hormone (GH) and ghrelin (GRL), have demonstrated their contributions to thymus biology. In the current review, we discuss the literature supporting a role for these hormones in thymic physiology and age-associated thymic involution and their potential use in the restoration of thymic function in aged and immunocompromised individuals.
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O'Brien M, Earley P, Morrison JJ, Smith TJ. Ghrelin in the human myometrium. Reprod Biol Endocrinol 2010; 8:55. [PMID: 20509935 PMCID: PMC2887880 DOI: 10.1186/1477-7827-8-55] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 05/28/2010] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Ghrelin is a 28-amino acid octanolyated peptide, synthesised primarily in the stomach. It stimulates growth hormone release, food intake and exhibits many other diverse effects. Our group have previously determined that ghrelin inhibited human contractility in vitro. The aim of this study therefore, was to investigate the expression of ghrelin, its receptor, the growth hormone secretagogue receptor type 1 (GHS-R1), ghrelin O-acyltransferase (GOAT) which catalyses ghrelin octanoylation, prohormone convertase 1/3 (PC1/3) responsible for pro-ghrelin processing, in human myometrium, during pregnancy prior to labour, during labour and in the non-pregnant state. Modulation of ghrelin and ghrelin receptor expression in cultured myometrial cells was also investigated. METHODS mRNA and protein were isolated from human myometrium and the myometrial smooth muscle cell line hTERT-HM; and real-time fluorescence RT-PCR, western blotting and fluorescence microscopy performed. The effects of beta-Estradiol and bacterial lipopolysaccharide (LPS) on hTERT-HM gene expression were evaluated by western blotting. RESULTS We have reported for the first time the expression and processing of ghrelin, GHS-R1, GOAT and PC1/3 expression in human myometrium, and also the down-regulation of ghrelin mRNA and protein expression during labour. Furthermore, GHS-R1 protein expression significantly decreased at labour. Myometrial GOAT expression significantly increased during term non-labouring pregnancy in comparison to both non-pregnant and labouring myometrium. Mature PC1/3 protein expression was significantly decreased at term pregnancy and labour in comparison to non-pregnant myometrium. Ghrelin, GHS-R1, GOAT and PC1/3 mRNA and protein expression was also detected in the hTERT-HM cells. Ghrelin protein expression decreased upon LPS treatment in these cells while beta-Estradiol treatment increased GHS-R1 expression. CONCLUSIONS Ghrelin processing occurred in the human myometrium at term pregnancy and in the non-pregnant state. GOAT expression which increased during term non-labouring pregnancy demonstrating a similar expression pattern to prepro-ghrelin and GHS-R1, decreased at labour, signifying possible myometrial ghrelin acylation. Moreover, the presence of PC1/3 may contribute to pro-ghrelin processing. These results along with the previous in vitro data suggest that myometrially-produced and processed ghrelin plays a significant autocrine or paracrine role in the maintenance of relaxation in this tissue during pregnancy. Furthermore, the significant uterine modulators LPS and beta-Estradiol are involved in the regulation of ghrelin and ghrelin receptor expression respectively, in the human myometrium.
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Affiliation(s)
- Margaret O'Brien
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland Galway, University Road, Galway, Ireland
| | - Padraig Earley
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland Galway, University Road, Galway, Ireland
| | - John J Morrison
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland Galway, University Road, Galway, Ireland
- Department of Obstetrics and Gynaecology, National University of Ireland Galway, Clinical Science Institute, University College Hospital Galway, Newcastle Road, Galway, Ireland
| | - Terry J Smith
- National Centre for Biomedical and Engineering Science, Orbsen Building, National University of Ireland Galway, University Road, Galway, Ireland
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Ghrelin improves LPS-induced gastrointestinal motility disturbances: roles of NO and prostaglandin E2. Shock 2010; 33:205-12. [PMID: 19503023 DOI: 10.1097/shk.0b013e3181ae841b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ghrelin, an important orexigenic peptide, exerts gastroprokinetic and anti-inflammatory effects. We investigated the role of ghrelin in LPS-induced gastrointestinal (GI) motility disturbances through NO and prostaglandin E2 pathways in mice. Ghrelin-containing cells and its receptor, growth hormone secretagogue receptor 1 (GHSR-1), were localized in the stomach and duodenum using an immunohistochemical method. The distribution of ghrelin-containing cells or GHSR-1 immunoreactivity in both the mucosal and the muscle layers was heterogeneous within both tissues. The i.p. administration of ghrelin (1-20 microg/kg) had no effect on gastric emptying but markedly increased the GI transit (GIT) in normal mice. LPS (20 mg/kg i.p.)-treated mice showed significant decreases in the gastric emptying and GIT. Ghrelin attenuated the LPS-induced delay in gastric emptying and GIT. We also performed immunohistochemical experiments on both tissues. Immunohistochemistry showed the presence of iNOS and cyclooxygenase 2 in both tissues of LPS-treated mice. Treatment of LPS-exposed mice with ghrelin (20 microg/kg) diminished the presence of iNOS but not cyclooxygenase 2 in both tissues. The effect of ghrelin on regulating LPS-induced GI motility disturbance was further found to be associated with a reduction in iNOS expression in the GI tract and plasma NO overproduction rather than regulation of neural or endothelial NO synthase expression in the GI tissue. In addition, ghrelin was found to elevate prostaglandin E2 levels in the GI tissue but showed no significant change in LPS-treated mice. These findings indicate that the action of ghrelin binding to GHSR-1 improves endotoxemia-induced GI motility disturbances mainly through down-regulating the NO pathway in the GI tract.
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de Segura IAG, Vallejo-Cremades MT, Lomas J, Sánchez MF, Caballero MI, Largo C, De Miguel E. Exogenous ghrelin regulates proliferation and apoptosis in the hypotrophic gut mucosa of the rat. Exp Biol Med (Maywood) 2010; 235:463-9. [DOI: 10.1258/ebm.2009.009247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ghrelin is the natural endogenous ligand for growth hormone secretagogue receptors. This peptide regulates energy homeostasis and expenditure and is a potential link between gut absorptive function and growth. We hypothesized that ghrelin may induce a proliferative and antiapoptotic action promoting the recovery of the hypotrophic gut mucosa. Therefore, the aim of the study was to determine the action of exogenous ghrelin following gut mucosal hypotrophia in rats fed an elemental diet. An elemental diet provides readily absorbable simple nutrients and is usually given to patients with absorptive dysfunction. Male Wistar rats ( n = 48) were fed the elemental diet for one week to induce mucosal hypotrophy and then treated for another week with systemic ghrelin and pair-fed with either a normoproteic or hyperproteic isocaloric liquid diet. Another group received a standard diet instead of the elemental diet and served as control (normotrophy). The elemental diet induced intestinal hypotrophia characterized by decreased proliferation in the ileum and increased apoptosis in jejunum and ileum. Ghrelin administration restored normal levels of proliferation in the ileum and apoptosis in the jejunum, with partial apoptosis restoration in the ileum. Ghrelin levels in plasma and fundus were increased in all groups, although the highest levels were found in rats treated with exogenous ghrelin. Ghrelin administration has a positive effect in the hypotrophic gut, regulating both proliferation and apoptosis towards a physiological balance counteracting the negative changes induced by an elemental diet in the intestines.
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Affiliation(s)
- Ignacio A Gómez de Segura
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
- Department of Medicine and Surgery, Veterinary Faculty, University Complutense of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid
| | - María Teresa Vallejo-Cremades
- Research Unit, Biomedical Research Foundation, Hospital Universitario La Paz, Madrid, Paseo de la Castellana, 261, 28046 Madrid, Spain
| | - Jesús Lomas
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
| | - Miriam F Sánchez
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
| | - María Isabel Caballero
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
| | - Carlota Largo
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
| | - Enrique De Miguel
- Department of Experimental Surgery, Hospital Universitario La Paz, Paseo de la Castellana, 261, 28046 Madrid
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Pierrakos C, Vincent JL. Sepsis biomarkers: a review. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R15. [PMID: 20144219 PMCID: PMC2875530 DOI: 10.1186/cc8872] [Citation(s) in RCA: 842] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 12/28/2009] [Accepted: 02/09/2010] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Biomarkers can be useful for identifying or ruling out sepsis, identifying patients who may benefit from specific therapies or assessing the response to therapy. METHODS We used an electronic search of the PubMed database using the key words "sepsis" and "biomarker" to identify clinical and experimental studies which evaluated a biomarker in sepsis. RESULTS The search retrieved 3370 references covering 178 different biomarkers. CONCLUSIONS Many biomarkers have been evaluated for use in sepsis. Most of the biomarkers had been tested clinically, primarily as prognostic markers in sepsis; relatively few have been used for diagnosis. None has sufficient specificity or sensitivity to be routinely employed in clinical practice. PCT and CRP have been most widely used, but even these have limited ability to distinguish sepsis from other inflammatory conditions or to predict outcome.
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Affiliation(s)
- Charalampos Pierrakos
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, route de Lennik 808, 1070 Brussels, Belgium.
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Kumar V, Sharma A. Is neuroimmunomodulation a future therapeutic approach for sepsis? Int Immunopharmacol 2010; 10:9-17. [DOI: 10.1016/j.intimp.2009.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 10/06/2009] [Accepted: 10/09/2009] [Indexed: 01/02/2023]
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Wang W, Bansal S, Falk S, Ljubanovic D, Schrier R. Ghrelin protects mice against endotoxemia-induced acute kidney injury. Am J Physiol Renal Physiol 2009; 297:F1032-7. [PMID: 19625378 DOI: 10.1152/ajprenal.00044.2009] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Acute kidney injury (AKI) in septic patients drastically increases the mortality to 50-80%. Sepsis is characterized by hemodynamic perturbations as well as overwhelming induction of proinflammatory cytokines. Since ghrelin has been shown to have anti-inflammatory properties, we hypothesized that ghrelin may afford renal protection during endotoxemia-induced AKI. Studies were conducted in a normotensive endotoxemia-induced AKI model in mice by intraperitoneal injection of 3.5 mg/kg LPS. Serum ghrelin levels were increased during endotoxemia accompanied by increased ghrelin receptor (GHSR-1a) protein expression in the kidney. Ghrelin administration (1.0 mg/kg sc 6 h and 30 min before and 14 h after LPS) significantly decreased serum cytokine levels (TNF-alpha, IL-1beta, and IL-6) and serum endothelin-1 levels which had been induced by LPS. The elevated serum nitric oxide (NO) levels and renal inducible NO synthase expression were also decreased by ghrelin. Renal TNF-alpha levels were also increased significantly in response to LPS and ghrelin significantly attenuated this increase. When administrated before LPS, ghrelin protected against the fall in glomerular filtration rate at 16 h (172.9 +/- 14.7 vs. 90.6 +/- 15.2 microl/min, P < 0.001) and 24 h (147.2 +/- 20.3 vs. 59.4 +/- 20.7 microl/min, P < 0.05) as well as renal blood flow at 16 h (1.65 +/- 0.07 vs. 1.47 +/- 0.04 ml/min, P < 0.01) and 24 h (1.56 +/- 0.08 vs. 1.22 +/- 0.03 ml/min, P < 0.05) after LPS administration without affecting mean arterial pressure. Ghrelin remained renal protective even when it was given after LPS. In summary, ghrelin offered significant protection against endotoxemia-induced AKI. The renal protective effect of ghrelin was associated with an inhibition of the proinflammatory cytokines. Of particular importance was the suppression of TNF-alpha both in the circulation and kidney tissues. Thus, ghrelin may be a promising peptide in managing endotoxemia-induced AKI.
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Affiliation(s)
- Wei Wang
- Dept. of Medicine, Univ. of Colorado Denver, Aurora, CO 80045, USA
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Hattori N. Expression, regulation and biological actions of growth hormone (GH) and ghrelin in the immune system. Growth Horm IGF Res 2009; 19:187-197. [PMID: 19144554 DOI: 10.1016/j.ghir.2008.12.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 11/05/2008] [Accepted: 12/08/2008] [Indexed: 12/20/2022]
Abstract
Immune and neuroendocrine systems have bidirectional communications. Growth hormone (GH) and an orexigenic hormone ghrelin are expressed in various immune cells such as T lymphocytes, B lymphocytes, monocytes and neutrophils. These immune cells also bear receptors for hormones: growth hormone receptor (GHR) for GH and growth hormone secretagogue receptor (GHS-R) for ghrelin. The expression of GH in immune cells is stimulated by ghrelin as in anterior pituitary cells, whereas the regulation of GH secretion in the immune system by other peptides seems to be different from that in the anterior pituitary gland. Cytokines and mitogens enhance GH secretion from immune cells. GH has several biological actions in the immune system: enhancing thymopoiesis and T cell development, modulating cytokine production, enhancing B cell development and antibody production, priming neutrophils and monocytes for superoxide anion secretion, enhancing neutrophil adhesion and monocyte migration and anti-apoptotic action. Biological actions of ghrelin include attenuation of septic shock and anti-inflammatory actions, modulating phagocytosis, and enhancing thymopoiesis. The effect of ghrelin may be direct or through GH production, and that of GH may be direct or through insulin like growth factor-I (IGF-I) production. Elucidation of the roles of GH and ghrelin in the immune system may shed light on the treatment and prevention of immunological disorders such as AIDS and organ damages due to obesity/ageing-related chronic inflammation.
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Affiliation(s)
- Naoki Hattori
- Department of Pharmacology, Kansai Medical University, Moriguchi-city, Osaka, Japan.
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Abstract
OBJECTIVE Evaluations of plasma leptin and ghrelin levels and their relations with circulating levels of proinflammatory mediators, stress hormones, and biochemical markers of hepatorenal injury during experimental endotoxemia in dogs. SETTING Uludag University. DESIGN Placebo-controlled animal study. ANIMALS Adult mongrel dogs (n = 16). INTERVENTIONS Intravenous injection of endotoxin (1 mg/kg) and blood sample withdrawal before and at 0.5-48 hrs posttreatment. MEASUREMENTS AND MAIN RESULTS Mean baseline plasma leptin and ghrelin levels were 2.4 +/- 0.1 ng/mL and 867 +/- 58 pg/mL, respectively. Plasma leptin and ghrelin increased significantly by 16% (p < .05) and 72% (p < .001) at 0.5 hr, and they remained elevated by 33-41% (p < .001) and 59-74% (p < .001) at 48 hrs after administration of endotoxin, respectively. There was positive correlation (r = .844; p < .001) between plasma leptin and ghrelin levels in endotoxin-treated dogs. Endotoxemia was associated with several-fold elevations in circulating levels of stress hormones, proinflammatory mediators, and hepatorenal injury markers. Plasma leptin and ghrelin levels in endotoxin-treated dogs were correlated with serum nitric oxide (r = .955 and r = .890; p < .001), procalcitonin (r = .825 and r = .716; p < .001), cortisol (r = .823 and r = .786; p < .001), and hepatorenal injury markers (r = .580 to .745 and r = .393 to .574; p < .05 to .01). CONCLUSIONS Circulating leptin and ghrelin levels increase during endotoxemia, and these increases are associated with elevated levels of proinflammatory mediators, stress hormones, and serum biochemical markers for hepatorenal dysfunction.
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Abstract
Advances in the understanding of appetite are leading to a refined concept of disease cachexia and point to novel therapeutic strategies based on the manipulation of appetite. The complex social and psychological short-term influences on appetite obscure the fact that over the longer term appetite is tightly regulated by physiological considerations; the homeostatic control of energy balance. Like obesity, which is now viewed as a disorder of homeostasis, cachexia can be seen as an adaptive response to the disease state that becomes harmful when prolonged. Several lines of evidence implicate a disorder of appetite regulation in the pathogenesis of cachexia. As the only known circulating mediator of increased appetite the peptide hormone ghrelin has attracted attention as a potential therapy. Trials in patients with various chronic illnesses, including cancer and kidney failure, have demonstrated short-term increases in energy intake. Trials in patients with emphysema and heart failure have also shown benefits in clinical outcomes such as lean body mass and exercise capacity, and longer-term trials using oral analogues are being undertaken. As well as improving nutrition, ghrelin has a number of other actions that may be useful, including an anti-inflammatory effect; of interest since many cachexias are associated with inappropriate immune activation. The manipulation of appetite, in particular by ghrelin agonism, is emerging as an exciting potential therapy for disease cachexia. Future research should focus on the ascertainment of clinically-relevant outcomes, and further characterisation of the non-nutritional effects of this pathway.
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Leptin and ghrelin: Through thick and thin*. Crit Care Med 2008; 36:1011-2. [DOI: 10.1097/ccm.0b013e318164ed48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Deboer MD, Zhu X, Levasseur PR, Inui A, Hu Z, Han G, Mitch WE, Taylor JE, Halem HA, Dong JZ, Datta R, Culler MD, Marks DL. Ghrelin treatment of chronic kidney disease: improvements in lean body mass and cytokine profile. Endocrinology 2008; 149:827-35. [PMID: 18039782 PMCID: PMC2219314 DOI: 10.1210/en.2007-1046] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chronic kidney disease (CKD) is associated with an increase in inflammatory cytokines and can result in cachexia with loss of muscle and fat stores. We previously demonstrated the efficacy of treating a model of cancer cachexia with ghrelin and a ghrelin receptor agonist. Currently, we examine a surgical model of CKD in rats, resulting in uremia and decreased accrual of lean body mass. Treatment with ghrelin and two ghrelin receptor agonists (BIM-28125 and BIM-28131) resulted in increased food intake and an improvement in lean body mass accrual that was related in part to a decrease in muscle protein degradation as assessed by muscle levels of the 14-kDa actin fragment resulting from cleaved actomyosin. Additionally, there was a decrease in circulating inflammatory cytokines in nephrectomized animals treated with ghrelin relative to saline treatment. Ghrelin-treated animals also had a decrease in the expression of IL-1 receptor in the brainstem and a decrease in expression of prohormone convertase-2, an enzyme involved in the processing of proopiomelanocortin to the anorexigenic peptide alpha-MSH. We conclude that ghrelin treatment in uremia results in improved lean mass accrual in part due to suppressed muscle proteolysis and possibly related to antiinflammatory effects.
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MESH Headings
- Absorptiometry, Photon
- Animals
- Body Weight/drug effects
- Cachexia/drug therapy
- Cachexia/etiology
- Cachexia/immunology
- Cytokines/blood
- Cytokines/genetics
- Dactinomycin/metabolism
- Disease Models, Animal
- Eating/drug effects
- Gene Expression/drug effects
- Ghrelin/pharmacology
- Growth Hormone/blood
- Inflammation/blood
- Inflammation/drug therapy
- Inflammation/etiology
- Insulin-Like Growth Factor I/metabolism
- Male
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Nephrectomy
- Neuropeptides/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred F344
- Receptors, Ghrelin/agonists
- Renal Insufficiency, Chronic/complications
- Renal Insufficiency, Chronic/drug therapy
- Renal Insufficiency, Chronic/immunology
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Affiliation(s)
- Mark D Deboer
- Department of Pediatrics, University of Virginia, Charlottesville, VA 22908, USA
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Becskei C, Riediger T, Hernádfalvy N, Arsenijevic D, Lutz TA, Langhans W. Inhibitory effects of lipopolysaccharide on hypothalamic nuclei implicated in the control of food intake. Brain Behav Immun 2008; 22:56-64. [PMID: 17624718 DOI: 10.1016/j.bbi.2007.06.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 06/01/2007] [Accepted: 06/02/2007] [Indexed: 10/23/2022] Open
Abstract
The arcuate nucleus (Arc) and the lateral hypothalamic area (LHA), two key hypothalamic nuclei regulating feeding behavior, express c-Fos, a marker of neuronal activation in fasted animals. This is reversed by refeeding. In the present study we tested whether an anorectic dose of lipopolysaccharide (LPS), the cell wall component of Gram-negative bacteria, also inhibits fasting-induced c-Fos expression in these hypothalamic nuclei. This would suggest that they are involved in anorexia during bacterial infections as well. We also studied whether LPS modulates the activity of orexin-A positive (OX+) LHA neurons. Food deprived BALB/c mice were injected with LPS or saline and were sacrificed 4 or 6h later. Four hours after injection, LPS reduced the number of c-Fos positive cells in the Arc and in the LHA, but had no effect on c-Fos in OX+ neurons. Six hours after injection, LPS reduced c-Fos expression in the LHA, both in the OX- and OX+ neurons, but not in the Arc. These results show that LPS modulates neuronal activity in the Arc and LHA similar to feeding-related stimuli, suggesting that the observed effects might contribute to the anorectic effect of LPS. Thus, physiological satiety signals released during refeeding and anorexia during bacterial infection seem to engage similar neuronal substrates.
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Affiliation(s)
- Csilla Becskei
- Institute of Veterinary Physiology and Zurich Centre of Human Integrative Physiology, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
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Granado M, Martín AI, López-Menduiña M, López-Calderón A, Villanúa MA. GH-releasing peptide-2 administration prevents liver inflammatory response in endotoxemia. Am J Physiol Endocrinol Metab 2008; 294:E131-41. [PMID: 17986630 DOI: 10.1152/ajpendo.00308.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been reported that growth hormone (GH)-releasing peptide-2 (GHRP-2), a ghrelin receptor agonist, has an anti-inflammatory effect. We investigated whether this GH secretagogue attenuates liver injury in LPS-treated rats. Wistar rats were simultaneously injected (ip) with LPS (1 mg/kg) and/or GHRP-2 (100 microg/kg). Serum levels of aspartate and alanine transaminases were measured as an index of liver damage. Circulating nitrites/nitrates and hepatic IGF-I and TNF-alpha were evaluated as possible mediators of GHRP-2 actions. LPS increased serum levels of transaminases and nitrites/nitrates. Moreover, LPS increased hepatic TNF-alpha and decreased hepatic IGF-I mRNAs. GHRP-2 administration attenuated the effects of LPS on transaminases, nitrites/nitrates, TNF-alpha, and IGF-I in vivo. This GHRP-2 effect does not seem to be due to modifications in food intake, since fasting did not modify serum levels of transaminases, serum nitrites/nitrates, and hepatic TNF-alpha mRNA both in vehicle rats and in LPS-injected rats. To elucidate whether GHRP-2 is acting directly on the liver, cocultures of hepatocytes and nonparenchymal cells and monocultures of isolated hepatocytes were incubated with LPS and GHRP-2. The ghrelin receptor agonist prevented an endotoxin-induced increase in transaminases and nitrite/nitrate release as well as in TNF-alpha mRNA and increased IGF-I mRNA from cocultures of hepatocytes and nonparenchymal cells, but not from monocultures. In summary, these data indicate that GHRP-2 has a protective effect on the liver in LPS-injected rats that seems to be mediated by IGF-I, TNF-alpha, and nitric oxide. Our data also suggest that the anti-inflammatory effect of GHRP-2 in the liver is exerted on nonparenchymal cells.
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Affiliation(s)
- Miriam Granado
- Department of Physiology, Faculty of Medicine, Complutense Univ., Avda. Complutense s/n, 28040 Madrid, Spain
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Exogenous ghrelin modulates release of pro-inflammatory and anti-inflammatory cytokines in LPS-stimulated macrophages through distinct signaling pathways. Surgery 2007; 143:334-42. [PMID: 18291254 DOI: 10.1016/j.surg.2007.09.039] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 09/20/2007] [Accepted: 09/27/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND Ghrelin, an orexigenic 28-amino-acid peptide, has been studied primarily in relation to the control of appetite and fat metabolism. In addition to these well-known functions, ghrelin, and its target receptors, growth hormone secretagogue receptors (GHS-Rs), have been localized to neutrophils, lymphocytes, and macrophages, which suggests that ghrelin may be involved in immune modulation. METHODS To assess the therapeutic role of ghrelin in production of pro-inflammatory and anti-inflammatory cytokines, the effects of exogenous ghrelin administration on the regulation of cytokine release in lipopolysaccharide (LPS)-activated murine RAW 264.7 macrophages were analyzed. RESULTS Ghrelin and GHS-Rs are expressed in murine macrophages. In addition, exogenous ghrelin inhibited the production of pro-inflammatory cytokines IL-1beta and TNF-alpha in LPS-stimulated murine macrophages in a dose dependent and time-dependent fashion. Exogenous ghrelin pretreatment resulted in a decrease in LPS-induced NFkappaB activation and was presumably the reason for this ghrelin-mediated effect. In contrast to these findings, exogenous ghrelin significantly augmented the release of the anti-inflammatory cytokine IL-10 in a dose-dependent and time-dependent fashion from LPS-stimulated murine macrophages. Ghrelin administration enhanced activation of p38 MAPK, which is known to control the release of IL-10 in macrophages independent of the NFkappaB pathway. These effects of ghrelin on both pro-inflammatory and anti-inflammatory cytokines were offset when a specific GHS-R receptor antagonist was added to the culture media. CONCLUSIONS These data suggest that ghrelin has potent anti-inflammatory properties through modulation of secretion of both pro-inflammatory and anti-inflammatory cytokines from LPS-stimulated macrophages through distinct signaling cascades. Therapeutic utility of ghrelin to control, modulate, or treat pathologic inflammatory conditions like endotoxemic shock and ulcerative colitis requires additional investigation.
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Abstract
Anorexia is part of the body's acute-phase response to illness. Microbial products such as lipopolysaccharides (LPS), which are also commonly used to model acute illness, trigger the acute-phase response and cause anorexia mainly through pro-inflammatory cytokines. LPS stimulate cytokine production through the cell-surface structural molecule CD14 and toll-like receptor-4. Cytokines ultimately change neural activity in brain areas controlling food intake and energy balance. The blood-brain barrier endothelial cells (BBB EC) are an important site of cytokine action in this context. BBB EC and perivascular cells (microglia and macrophages) form a complex regulatory interface that modulates neuronal activity by the release of messengers (e.g. PG, NO) in response to peripheral challenges. Serotonergic neurons originating in the raphe nuclei and glucagon-like peptide-1-expressing neurons in the hindbrain may be among the targets of these messengers, because serotonin (5-HT), acting through the 5-HT2C receptor, and glucagon-like peptide-1 have recently emerged as neurochemical mediators of LPS anorexia. The central melanocortin system, which is a downstream target of serotonergic neurons, also appears to be involved in mediation of LPS anorexia. Interestingly, LPS also reduce orexin expression and the activity of orexin neurons in the lateral hypothalamic area of fasted mice. As the eating-stimulatory properties of orexin are apparently related to arousal, the inhibitory effect of LPS on orexin neurons might be involved in LPS-induced inactivity and anorexia. In summary, the immune signalling pathways of LPS-induced, and presumably acute illness-induced, anorexia converge on central neural signalling systems that control food intake and energy balance in healthy individuals.
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Affiliation(s)
- Wolfgang Langhans
- Physiology and Behaviour Group, Institute of Animal Sciences, ETH Zurich, Schwerzenbach, Switzerland.
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Vila G, Maier C, Riedl M, Nowotny P, Ludvik B, Luger A, Clodi M. Bacterial endotoxin induces biphasic changes in plasma ghrelin in healthy humans. J Clin Endocrinol Metab 2007; 92:3930-4. [PMID: 17666475 DOI: 10.1210/jc.2007-1194] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Ghrelin is a gut hormone with a highly preserved biological activity, which seems not to be restricted to the regulation of food intake, body composition, and growth. Continuous research is unraveling new properties of ghrelin, among others cardiovascular and antiinflammatory activities. Ghrelin is recently implicated in the host response to bacterial endotoxin in rodents and suggested as a possible therapeutic tool in sepsis. OBJECTIVE This study aimed to investigate plasma ghrelin levels during human bacterial endotoxemia. DESIGN AND SETTING We conducted a randomized, placebocontrolled, crossover clinical trial at a university medical center. STUDY PARTICIPANTS Participants included 10 healthy men. INTERVENTION After an overnight fast, study subjects were randomized to 2 ng/kg Escherichia coli endotoxin [lipopolysaccharide (LPS)] or placebo and monitored for 6 h. MAIN OUTCOME MEASURES We measured ghrelin, GH, ACTH, cortisol, glucose, free fatty acids, TNF-alpha, IL-6, and IL-1 receptor antagonist. RESULTS LPS administration induced a rapid ghrelin surge at 120 min (Delta ghrelin 100.2 +/- 30.3 vs. 7.2 +/- 26.4 pg/ml on the placebo day, P = 0.042). This ghrelin peak occurred 30 min after the TNF-alpha peak and corresponded with IL-6, GH, and ACTH peaks. Starting from 120 min and thereafter, ghrelin continuously decreased, reaching a nadir at 5 h after LPS administration (Delta ghrelin, -43.8 +/- 28.4 compared with 70.3 +/- 38.2 pg/ml on the control days, P = 0.038). CONCLUSIONS Ghrelin is one of the first hormones rapidly increasing in the human physiological response to bacterial endotoxic shock. Plasma ghrelin might be part of the complex immuno-neuroendocrine mechanisms activated by systemic infection and inflammation in humans.
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Affiliation(s)
- Greisa Vila
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, A-1090, Vienna, Austria
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Prenzler NK, Macke C, Horn R, Brabant G, Pabst R, Richter M, Nave H. Obesity influences the food consumption and cytokine pattern in ghrelin-treated endotoxemic rats. Life Sci 2007; 81:80-7. [PMID: 17532346 DOI: 10.1016/j.lfs.2007.04.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 04/18/2007] [Accepted: 04/23/2007] [Indexed: 12/27/2022]
Abstract
Obese patients have an increased incidence of systemic infections and higher morbidity and mortality rates than normal weight subjects. Ghrelin is a potent orexigenic signal from the stomach and seems to play a role in the generation and control of immune interactions. To examine a possible benefit of a single ghrelin application on acute endotoxemia, chronic intravenous (i.v.) cannulated lean and diet-induced obese male LEW rats were treated with a bolus injection of either ghrelin (10 nmol/kg) or vehicle, 10 min prior to a challenge with a sublethal bolus of endotoxin (100 microg/kg) or vehicle. Multiple blood samples were taken within a period from 24 h before the experiment up to 24 h after the endotoxin challenge to measure ghrelin and cytokine levels. Additionally, food consumption was recorded and ghrelin expression in fore- and glandular stomach was evaluated immunohistochemically. Despite higher serum ghrelin levels, the food consumption was significantly decreased in obese endotoxemic rats compared to lean littermates after ghrelin treatment. Furthermore we could show an increase of anti-inflammatory IL-10 serum levels after ghrelin treatment of normal weight endotoxemic and an opposite effect in obese animals. As the therapy of disease-associated cachexia and various immunological problems in endotoxemia is still insufficient, peptides such as ghrelin with their modulating abilities for the endocrine and the immune system are of special interest. However, the present study shows that the beneficial effects of ghrelin were attenuated in obese endotoxemic animals. These data further document the necessity to differentiate between normal weight and obese subjects in the attempt to establish ghrelin as a therapeutic target in endotoxemia.
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Affiliation(s)
- Nils K Prenzler
- Department of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str.1, 30625 Hannover, Germany
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Harada N, Kusuyama A, Morishima M, Okada K, Takahashi A, Nakaya Y. Bezafibrate improves bacterial lipopolysaccharide-induced dyslipidemia and anorexia in rats. Metabolism 2007; 56:517-22. [PMID: 17379010 DOI: 10.1016/j.metabol.2006.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Accepted: 11/06/2006] [Indexed: 11/24/2022]
Abstract
Bacterial endotoxin/lipopolysaccharide (LPS)-induced cachexia is characterized by weight loss, anorexia, and a disturbance in lipid metabolism, namely, hypertriacylglycerolemia. The aim of this study in rats with acute endotoxicity induced by an injection of LPS was to investigate whether bezafibrate, a ligand for peroxisome proliferator-activated receptor alpha and a lipoprotein lipase (LPL) activator, improved cachectic conditions, including impaired lipid metabolism. Short-term administration of LPS in the rats resulted in impairment of triacylglycerol clearance in plasma after the intake of fresh cream. In addition, LPS increased whole-body energy expenditure, reduced fasting body weight and caused anorexia in the rats. Bezafibrate treatment resulted in significant improvements in LPS-induced dyslipidemia and anorexia, but had no effect on energy expenditure, respiratory quotient, or fasting body weight in the endotoxic rats. Administration of LPS was also associated with a decrease in the level of messenger RNA (mRNA) expression for LPL in white adipose tissue and skeletal muscle and an increase in the mRNA levels for uncoupling protein 3 in skeletal muscle. Bezafibrate treatment reversed the decline in LPL mRNA levels in white adipose tissue but not in the skeletal muscle tissue of the rats. The enhanced uncoupling protein 3 mRNA level in the endotoxic rats was not affected by bezafibrate treatment. Plasma concentration of leptin was increased by short-term LPS treatment. Bezafibrate decreased the level of plasma leptin significantly without affecting the level of leptin mRNA expression. These results suggest that bezafibrate may be an effective drug not only for impaired triacylglycerol metabolism, but also for anorexia in cachectic states induced by bacterial infections.
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Affiliation(s)
- Nagakatsu Harada
- Department of Nutrition and Metabolism, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima City, 770-8503, Japan.
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