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Noh JY, Han HW, Kim DM, Giles ED, Farnell YZ, Wright GA, Sun Y. Innate immunity in peripheral tissues is differentially impaired under normal and endotoxic conditions in aging. Front Immunol 2024; 15:1357444. [PMID: 39221237 PMCID: PMC11361940 DOI: 10.3389/fimmu.2024.1357444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 07/22/2024] [Indexed: 09/04/2024] Open
Abstract
Chronic low-grade inflammation is a hallmark of aging, aka "inflammaging", which is linked to a wide range of age-associated diseases. Immune dysfunction increases disease susceptibility, and increases morbidity and mortality of aging. Innate immune cells, including monocytes, macrophages and neutrophils, are the first responders of host defense and the key mediators of various metabolic and inflammatory insults. Currently, the understanding of innate immune programming in aging is largely fragmented. Here we investigated the phenotypic and functional properties of innate immune cells in various peripheral tissues of young and aged mice under normal and endotoxic conditions. Under the steady state, aged mice showed elevated pro-inflammatory monocytes/macrophages in peripheral blood, adipose tissue, liver, and colon. Under lipopolysaccharide (LPS)-induced inflammatory state, the innate immune cells of aged mice showed a different response to LPS stimulus than that of young mice. LPS-induced immune responses displayed differential profiles in different tissues and cell types. In the peripheral blood, when responding to LPS, the aged mice showed higher neutrophils, but lower pro-inflammatory monocytes than that in young mice. In the peritoneal fluid, while young mice exhibited significantly elevated pro-inflammatory neutrophils and macrophages in response to LPS, aged mice exhibited decreased pro-inflammatory neutrophils and variable cytokine responses in macrophages. In the adipose tissue, LPS induced less infiltrated neutrophils but more infiltrated macrophages in old mice than young mice. In the liver, aged mice showed a more robust increase of pro-inflammatory macrophages compared to that in young mice under LPS stimulation. In colon, macrophages showed relatively mild response to LPS in both young and old mice. We have further tested bone-marrow derived macrophages (BMDM) from young and aged mice, we found that BMDM from aged mice have impaired polarization, displaying higher expression of pro-inflammatory markers than those from young mice. These data collectively suggest that innate immunity in peripheral tissues is impaired in aging, and the dysregulation of immunity is tissue- and cell-dependent. Our findings in the rodent model underscore the complexity of aging immunity. Further investigation is needed to determine whether the immune profile observed in aged mice is applicable in age-associated diseases in humans.
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Affiliation(s)
- Ji Yeon Noh
- Department of Nutrition, Texas A&M University, College Station, TX, United States
| | - Hye Won Han
- Department of Nutrition, Texas A&M University, College Station, TX, United States
| | - Da Mi Kim
- Department of Nutrition, Texas A&M University, College Station, TX, United States
| | - Erin D. Giles
- School of Kinesiology, University of Michigan, Ann Arbor, MI, United States
| | - Yuhua Z. Farnell
- Department of Poultry Science, Texas A&M University, College Station, TX, United States
| | - Gus A. Wright
- Department of Veterinary Pathobiology, Texas A&M University,
College Station, TX, United States
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M University, College Station, TX, United States
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, United States
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2
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Lékó AH, Gregory-Flores A, Marchette RCN, Gomez JL, Vendruscolo JCM, Repunte-Canonigo V, Choung V, Deschaine SL, Whiting KE, Jackson SN, Cornejo MP, Perello M, You ZB, Eckhaus M, Rasineni K, Janda KD, Zorman B, Sumazin P, Koob GF, Michaelides M, Sanna PP, Vendruscolo LF, Leggio L. Genetic or pharmacological GHSR blockade has sexually dimorphic effects in rodents on a high-fat diet. Commun Biol 2024; 7:632. [PMID: 38796563 PMCID: PMC11127961 DOI: 10.1038/s42003-024-06303-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 05/08/2024] [Indexed: 05/28/2024] Open
Abstract
The stomach-derived hormone ghrelin regulates essential physiological functions. The ghrelin receptor (GHSR) has ligand-independent actions; therefore, GHSR gene deletion may be a reasonable approach to investigate the role of this system in feeding behaviors and diet-induced obesity (DIO). Here, we investigate the effects of a long-term (12-month) high-fat (HFD) versus regular diet on obesity-related measures in global GHSR-KO and wild-type (WT) Wistar male and female rats. Our main findings are that the GHSR gene deletion protects against DIO and decreases food intake during HFD in male but not in female rats. GHSR gene deletion increases thermogenesis and brain glucose uptake in male rats and modifies the effects of HFD on brain glucose metabolism in a sex-specific manner, as assessed with small animal positron emission tomography. We use RNA-sequencing to show that GHSR-KO rats have upregulated expression of genes responsible for fat oxidation in brown adipose tissue. Central administration of a novel GHSR inverse agonist, PF-5190457, attenuates ghrelin-induced food intake, but only in male, not in female mice. HFD-induced binge-like eating is reduced by inverse agonism in both sexes. Our results support GHSR as a promising target for new pharmacotherapies for obesity.
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Affiliation(s)
- András H Lékó
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA
- Center on Compulsive Behaviors, Intramural Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Adriana Gregory-Flores
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Renata C N Marchette
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, Neuroimaging Research Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Janaina C M Vendruscolo
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Vez Repunte-Canonigo
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Vicky Choung
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Sara L Deschaine
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA
| | - Kimberly E Whiting
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Shelley N Jackson
- Translational Analytical Core, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Maria Paula Cornejo
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional La Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Argentina
| | - Mario Perello
- Grupo de Neurofisiología, Instituto Multidisciplinario de Biología Celular (IMBICE), Universidad Nacional La Plata (UNLP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) y Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-PBA), La Plata, Argentina
| | - Zhi-Bing You
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Michael Eckhaus
- Pathology Service, Division of Veterinary Resources, Office of Research Services, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Karuna Rasineni
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kim D Janda
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Barry Zorman
- Department of Pediatrics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Pavel Sumazin
- Department of Pediatrics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - George F Koob
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, Neuroimaging Research Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Pietro P Sanna
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Leandro F Vendruscolo
- Stress and Addiction Neuroscience Unit, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA.
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore, MD, USA.
- Translational Analytical Core, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA.
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, RI, USA.
- Division of Addiction Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
- Department of Neuroscience, Georgetown University Medical Center, Washington DC, USA.
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3
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Han HW, Pradhan G, Villarreal D, Kim DM, Jain A, Gaharwar A, Tian Y, Guo S, Sun Y. GHSR Deletion in β-Cells of Male Mice: Ineffective in Obesity, but Effective in Protecting against Streptozotocin-Induced β-Cell Injury in Aging. Nutrients 2024; 16:1464. [PMID: 38794702 PMCID: PMC11123813 DOI: 10.3390/nu16101464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
Insulin secretion from pancreatic β cells is a key pillar of glucose homeostasis, which is impaired under obesity and aging. Growth hormone secretagogue receptor (GHSR) is the receptor of nutrient-sensing hormone ghrelin. Previously, we showed that β-cell GHSR regulated glucose-stimulated insulin secretion (GSIS) in young mice. In the current study, we further investigated the effects of GHSR on insulin secretion in male mice under diet-induced obesity (DIO) and streptozotocin (STZ)-induced β-cell injury in aging. β-cell-specific-Ghsr-deficient (Ghsr-βKO) mice exhibited no glycemic phenotype under DIO but showed significantly improved ex vivo GSIS in aging. We also detected reduced insulin sensitivity and impaired insulin secretion during aging both in vivo and ex vivo. Accordingly, there were age-related alterations in expression of glucose transporter, insulin signaling pathway, and inflammatory genes. To further determine whether GHSR deficiency affected β-cell susceptibility to acute injury, young, middle-aged, and old Ghsr-βKO mice were subjected to STZ. We found that middle-aged and old Ghsr-βKO mice were protected from STZ-induced hyperglycemia and impaired insulin secretion, correlated with increased expression of insulin signaling regulators but decreased pro-inflammatory cytokines in pancreatic islets. Collectively, our findings indicate that β-cell GHSR has a major impact on insulin secretion in aging but not obesity, and GHSR deficiency protects against STZ-induced β-cell injury in aging.
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Affiliation(s)
- Hye Won Han
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (H.W.H.)
| | - Geetali Pradhan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Daniel Villarreal
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (H.W.H.)
| | - Da Mi Kim
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (H.W.H.)
| | - Abhishek Jain
- Department of Biomedical Engineering, College of Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Akhilesh Gaharwar
- Department of Biomedical Engineering, College of Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Yanan Tian
- Department of Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Shaodong Guo
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (H.W.H.)
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (H.W.H.)
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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4
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Yang YY, Qi JJ, Jiang SY, Ye L. Esculin ameliorates obesity-induced insulin resistance by improving adipose tissue remodeling and activating the IRS1/PI3K/AKT/GLUT4 pathway. JOURNAL OF ETHNOPHARMACOLOGY 2024; 319:117251. [PMID: 37778516 DOI: 10.1016/j.jep.2023.117251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 09/13/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Cortex fraxini (also known as qinpi)-the bark of Fraxinus rhynchophylla Hance (Oleaceae)-is widely used as a Chinese traditional medicinal for its anti-inflammatory and anti-hyperuricemic activities. AIM OF THE STUDY Obesity-induced insulin resistance (IR) is driving the rising incidence of type 2 diabetes mellitus and is related to pathological adipose tissue remodeling. Esculin, a major active component of Cortex fraxini, has anti-diabetic effects. However, whether esculin improves obesity-induced IR by regulating adipose tissue remodeling is unclear. The aims of the present study were to assess the effects of esculin on obesity-induced IR and to explore the underlying mechanisms. MATERIALS AND METHODS Obese IR C57BL/6J mice were treated with esculin (40 or 80 mg/kg/day) for 4 weeks. Oral glucose tolerance tests were used to assess insulin sensitivity. Histological analyses were performed to analyze the number and size distribution of adipocytes. Glucose uptake was assessed using 2-NBDG. RESULTS Esculin had no effect on body weight gain but reduced fasting blood glucose, improved oral glucose tolerance, and increased insulin sensitivity. Esculin reduced adipocyte size and the expression levels of collagen 4A1 and tumor necrosis factor α and increased the number of adipocytes and the expression of vascular endothelial growth factor A. Esculin promoted the differentiation of 3T3-L1 cells and upregulated the mRNA expression of CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor-γ, activated the insulin receptor substrate 1 (IRS1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and enhanced the translocation of glucose transporter type 4 (GLUT4) and glucose uptake in adipocytes treated with palmitic acid. CONCLUSIONS These data suggest that esculin increases insulin sensitivity by improving adipose tissue remodeling and activating the IRS1/PI3K/AKT/GLUT4 pathway.
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Affiliation(s)
- Yong-Yu Yang
- Department of Pharmacy, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China; Hunan Provincial Engineering Research Central of Translational Medical and Innovative Drug, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Jing-Jing Qi
- Department of Geriatrics, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Si-Yi Jiang
- Department of Pharmacy, Medical College, Yueyang Vocational Technical College, YueYang, Hunan, China.
| | - Ling Ye
- Department of Geriatrics, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
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5
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Leggio L, Leko A, Gregory-Flores A, Marchette R, Gomez J, Vendruscolo J, Repunte-Canonigo V, Chuong V, Deschaine S, Whiting K, Jackson S, Cornejo M, Perello M, You ZB, Eckhaus M, Janda K, Zorman B, Sumazin P, Koob G, Michaelides M, Sanna PP, Vendruscolo L. Genetic or pharmacological GHSR blockade has sexually dimorphic effects in rodents on a high-fat diet. RESEARCH SQUARE 2023:rs.3.rs-3236045. [PMID: 37886546 PMCID: PMC10602167 DOI: 10.21203/rs.3.rs-3236045/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The stomach-derived hormone ghrelin regulates essential physiological functions. The ghrelin receptor (GHSR) has ligand-independent actions, therefore, GHSR gene deletion may be a reasonable approach to investigate the role of this system in feeding behaviors and diet-induced obesity (DIO). Here we investigated the effects of a long-term (12 month) high-fat (HFD) versus regular diet on obesity-related measures in global GHSR-KO and wild type (WT) Wistar male and female rats. Our main findings were that the GHSR gene deletion protects against DIO and decreases food intake during HFD in male but not in female rats. GHSR gene deletion increased thermogenesis and brain glucose uptake in male rats and modified the effects of HFD on brain glucose metabolism in a sex-specific manner, as assessed with small animal positron emission tomography. RNA-sequencing was also used to show that GHSR-KO rats had upregulated expression of genes responsible for fat oxidation in brown adipose tissue. Central administration of a novel GHSR inverse agonist, PF-5190457, attenuated ghrelin-induced food intake, but only in male, not in female mice. HFD-induced binge-like eating was reduced by inverse agonism in both sexes. Our results support GHSR as a promising target for new pharmacotherapies for obesity.
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6
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O’Reilly C, Lin L, Wang H, Fluckey J, Sun Y. Ablation of Ghrelin Receptor Mitigates the Metabolic Decline of Aging Skeletal Muscle. Genes (Basel) 2022; 13:genes13081368. [PMID: 36011279 PMCID: PMC9407208 DOI: 10.3390/genes13081368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/23/2022] [Accepted: 07/26/2022] [Indexed: 02/04/2023] Open
Abstract
The orexigenic hormone ghrelin has multifaceted roles in health and disease. We have reported that ablation of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), protects against metabolic dysfunction of adipose tissues in aging. Our further observation interestingly revealed that GHS-R deficiency phenocopies the effects of myokine irisin. In this study, we aim to determine whether GHS-R affects the metabolic functions of aging skeletal muscle and whether GHS-R regulates the muscular functions via irisin. We first studied the expression of metabolic signature genes in gastrocnemius muscle of young, middle-aged and old mice. Then, old GHS-R knockout (Ghsr−/−) mice and their wild type counterparts were used to assess the impact of GHS-R ablation on the metabolic characteristics of gastrocnemius and soleus muscle. There was an increase of GHS-R expression in skeletal muscle during aging, inversely correlated with the decline of metabolic functions. Remarkedly the muscle of old GHS-R knockout (Ghsr−/−) mice exhibited a youthful metabolic profile and better maintenance of oxidative type 2 muscle fibers. Furthermore, old Ghsr−/− mice showed improved treadmill performance, supporting better functionality. Also intriguing to note was the fact that old GHS-R-ablated mice showed increased expression of the irisin precursor FNDC5 in the muscle and elevated plasma irisin levels in circulation, which supports a potential interrelationship between GHS-R and irisin. Overall, our work suggests that GHS-R has deleterious effects on the metabolism of aging muscle, which may be at least partially mediated by myokine irisin.
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Affiliation(s)
- Colleen O’Reilly
- Department of Health and Kinesiology, Texas A & M University, College Station, TX 77843, USA;
| | - 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, Macau 999078, China
| | - Hongying Wang
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
| | - James Fluckey
- Department of Health and Kinesiology, Texas A & M University, College Station, TX 77843, USA;
- Correspondence: (J.F.); (Y.S.)
| | - Yuxiang Sun
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Department of Nutrition, Texas A & M University, College Station, TX 77843, USA;
- Correspondence: (J.F.); (Y.S.)
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7
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Noh JY, Wu CS, DeLuca JAA, Devaraj S, Jayaraman A, Alaniz RC, Tan XD, Allred CD, Sun Y. Novel Role of Ghrelin Receptor in Gut Dysbiosis and Experimental Colitis in Aging. Int J Mol Sci 2022; 23:2219. [PMID: 35216335 PMCID: PMC8875592 DOI: 10.3390/ijms23042219] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 01/25/2023] Open
Abstract
Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout (KO) mice. While young GHS-R KO mice showed marginal changes in Bacteroidetes and Firmicutes, aged GHS-R KO mice exhibited reduced Bacteroidetes and increased Firmicutes, featuring a disease-susceptible microbiome profile. To further study the role of GHS-R in intestinal inflammation in aging, we induced acute colitis in young and aged GHS-R KO mice using dextran sulfate sodium (DSS). The GHS-R KO mice showed more severe disease activity scores, higher proinflammatory cytokine expression, and decreased expression of tight junction markers. These results suggest that GHS-R plays an important role in microbiome homeostasis and gut inflammation during aging; GHS-R suppression exacerbates intestinal inflammation in aging and increases vulnerability to colitis. Collectively, our finding reveals for the first time that GHS-R is an important regulator of intestinal health in aging; targeting GHS-R may present a novel therapeutic strategy for prevention/treatment of aging leaky gut and inflammatory bowel disease.
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Affiliation(s)
- Ji Yeon Noh
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (J.Y.N.); (C.-S.W.); (J.A.A.D.); (C.D.A.)
| | - Chia-Shan Wu
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (J.Y.N.); (C.-S.W.); (J.A.A.D.); (C.D.A.)
| | - Jennifer A. A. DeLuca
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (J.Y.N.); (C.-S.W.); (J.A.A.D.); (C.D.A.)
| | - Sridevi Devaraj
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Arul Jayaraman
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA;
| | - Robert C. Alaniz
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX 77843, USA;
| | - Xiao-Di Tan
- Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Clinton D. Allred
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (J.Y.N.); (C.-S.W.); (J.A.A.D.); (C.D.A.)
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC 27412, USA
| | - Yuxiang Sun
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA; (J.Y.N.); (C.-S.W.); (J.A.A.D.); (C.D.A.)
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
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8
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Hucik B, Lovell AJ, Hoecht EM, Cervone DT, Mutch DM, Dyck DJ. Regulation of adipose tissue lipolysis by ghrelin is impaired with high-fat diet feeding and is not restored with exercise. Adipocyte 2021; 10:338-349. [PMID: 34224298 PMCID: PMC8259717 DOI: 10.1080/21623945.2021.1945787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Ghrelin is released from the stomach as an anticipatory signal prior to a meal and decreases immediately after. Previous research has shown that both acylated (AG) and unacylated (UnAG) ghrelin blunt adrenoreceptor-stimulated lipolysis in rat white adipose tissue (WAT) ex vivo. We investigated whether acute or chronic consumption of a high fat diet (HFD) impaired the ability of ghrelin to regulate adipose tissue lipolysis, and if this impairment could be restored with exercise. After 5 days (5d) of a HFD, or 6 weeks (6 w) of a HFD (60% kcal from fat) with or without exercise training, inguinal and retroperitoneal WAT was collected from anesthetized rats for adipose tissue organ culture. Samples were treated with 1 μM CL 316,243 (CL; lipolytic control), 1 μM CL+150 ng/ml AG or 1 μM CL+150 ng/ml UnAG. Incubation media and tissue were collected after 2 hours. Colorometric assays were used to determine glycerol and free fatty acid (FFA) concentrations in media. Western blots were used to quantify the protein content of lipolytic enzymes and ghrelin receptors in both depots. CL stimulated lipolysis was evidenced by increases in glycerol (p < 0.0001) and FFA (p < 0.0001) concentrations in media compared to control. AG decreased CL-stimulated glycerol release in inguinal WAT from 5d LFD rats (p = 0.0097). Neither AG nor UnAG blunted lipolysis in adipose tissue from 5d or 6 w HFD-fed rats, and exercise did not restore ghrelin’s anti-lipolytic ability in 6 w HFD-fed rats. Overall, this study demonstrates that HFD consumption impairs ghrelin’s ability to regulate adipose tissue lipolysis.
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Affiliation(s)
- Barbora Hucik
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Andrew J. Lovell
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Evan M. Hoecht
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Daniel T. Cervone
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - David M. Mutch
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - David J. Dyck
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Peris-Sampedro F, Le May MV, Stoltenborg I, Schéle E, Dickson SL. A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? J Neuroendocrinol 2021; 33:e13025. [PMID: 34427011 DOI: 10.1111/jne.13025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/09/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
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Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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