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List EO, Duran-Ortiz S, Kulkarni P, Davis E, Mora-Criollo P, Berryman DE, Kopchick JJ. Growth hormone receptor gene disruption. VITAMINS AND HORMONES 2023; 123:109-149. [PMID: 37717983 DOI: 10.1016/bs.vh.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Much of our understanding of growth hormone's (GH)'s numerous activities stems from studies utilizing GH receptor (GHR) knockout mice. More recently, the role of GH action has been examined by creating mice with tissue-specific or temporal GHR disruption. To date, 37 distinct GHR knockout mouse lines have been created. Targeted tissues include fat, liver, muscle, heart, bone, brain, macrophage, intestine, hematopoietic stem cells, pancreatic β cells, and inducible multi-tissue "global" disruption at various ages. In this chapter, a summary of each mouse line is provided with background information on the generation of the mouse line as well as important physiological outcomes resulting from GHR gene disruption. Collectively, these mouse lines provide unique insights into GH action and have resulted in the development of new hypotheses about the functions ascribed to GH action in particular tissues.
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Affiliation(s)
- Edward O List
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Silvana Duran-Ortiz
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Prateek Kulkarni
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Emily Davis
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Patricia Mora-Criollo
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Darlene E Berryman
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - John J Kopchick
- The Edison Biotechnology Institute, and the Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States.
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2
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List EO, Berryman DE, Slyby J, Duran-Ortiz S, Funk K, Bisset ES, Howlett SE, Kopchick JJ. Disruption of Growth Hormone Receptor in Adipocytes Improves Insulin Sensitivity and Lifespan in Mice. Endocrinology 2022; 163:bqac129. [PMID: 35952979 PMCID: PMC9467438 DOI: 10.1210/endocr/bqac129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Indexed: 11/19/2022]
Abstract
Growth hormone receptor knockout (GHRKO) mice have been used for 25 years to uncover some of the many actions of growth hormone (GH). Since they are extremely long-lived with enhanced insulin sensitivity and protected from multiple age-related diseases, they are often used to study healthy aging. To determine the effect that adipose tissue has on the GHRKO phenotype, our laboratory recently created and characterized adipocyte-specific GHRKO (AdGHRKO) mice, which have increased adiposity but appear healthy with enhanced insulin sensitivity. To test the hypothesis that removal of GH action in adipocytes might partially replicate the increased lifespan and healthspan observed in global GHRKO mice, we assessed adiposity, cytokines/adipokines, glucose homeostasis, frailty, and lifespan in aging AdGHRKO mice of both sexes. Our results show that disrupting the GH receptor gene in adipocytes improved insulin sensitivity at advanced age and increased lifespan in male AdGHRKO mice. AdGHRKO mice also exhibited increased fat mass, reduced circulating levels of insulin, c-peptide, adiponectin, resistin, and improved frailty scores with increased grip strength at advanced ages. Comparison of published mean lifespan data from GHRKO mice to that from AdGHRKO and muscle-specific GHRKO mice suggests that approximately 23% of lifespan extension in male GHRKO is due to GHR disruption in adipocytes vs approximately 19% in muscle. Females benefited less from GHR disruption in these 2 tissues with approximately 19% and approximately 0%, respectively. These data indicate that removal of GH's action, even in a single tissue, is sufficient for observable health benefits that promote long-term health, reduce frailty, and increase longevity.
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Affiliation(s)
- Edward O List
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
- Department of Specialty Medicine, Heritage College of Osteopathic Medicine, Athens, Ohio 45701, USA
| | - Darlene E Berryman
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Athens, Ohio 45701, USA
| | - Julie Slyby
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
| | | | - Kevin Funk
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
| | - Elise S Bisset
- Department of Pharmacology Dalhousie University Halifax, Halifax , Nova Scotia , Canada
| | - Susan E Howlett
- Department of Pharmacology Dalhousie University Halifax, Halifax , Nova Scotia , Canada
- Department of Medicine (Geriatric Medicine), Dalhousie University Halifax, Halifax , Nova Scotia , Canada
| | - John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Athens, Ohio 45701, USA
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3
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Bartke A. Benefits of Living Without Growth Hormone. J Gerontol A Biol Sci Med Sci 2021; 76:1769-1774. [PMID: 34036341 DOI: 10.1093/gerona/glab147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, USA
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Chhabra Y, Nelson CN, Plescher M, Barclay JL, Smith AG, Andrikopoulos S, Mangiafico S, Waxman DJ, Brooks AJ, Waters MJ. Loss of growth hormone-mediated signal transducer and activator of transcription 5 (STAT5) signaling in mice results in insulin sensitivity with obesity. FASEB J 2019; 33:6412-6430. [PMID: 30779881 PMCID: PMC6463913 DOI: 10.1096/fj.201802328r] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Growth hormone (GH) has an important function as an insulin antagonist with elevated insulin sensitivity evident in humans and mice lacking a functional GH receptor (GHR). We sought the molecular basis for this sensitivity by utilizing a panel of mice possessing specific deletions of GHR signaling pathways. Metabolic clamps and glucose homeostasis tests were undertaken in these obese adult C57BL/6 male mice, which indicated impaired hepatic gluconeogenesis. Insulin sensitivity and glucose disappearance rate were enhanced in muscle and adipose of mice lacking the ability to activate the signal transducer and activator of transcription (STAT)5 via the GHR (Ghr-391-/-) as for GHR-null (GHR-/-) mice. These changes were associated with a striking inhibition of hepatic glucose output associated with altered glycogen metabolism and elevated hepatic glycogen content during unfed state. The enhanced hepatic insulin sensitivity was associated with increased insulin receptor β and insulin receptor substrate 1 activation along with activated downstream protein kinase B signaling cascades. Although phosphoenolpyruvate carboxykinase (Pck)-1 expression was unchanged, its inhibitory acetylation was elevated because of decreased sirtuin-2 expression, thereby promoting loss of PCK1. Loss of STAT5 signaling to defined chromatin immunoprecipitation targets would further increase lipogenesis, supporting hepatosteatosis while lowering glucose output. Finally, up-regulation of IL-15 expression in muscle, with increased secretion of adiponectin and fibroblast growth factor 1 from adipose tissue, is expected to promote insulin sensitivity.-Chhabra, Y., Nelson, C. N., Plescher, M., Barclay, J. L., Smith, A. G., Andrikopoulos, S., Mangiafico, S., Waxman, D. J., Brooks, A. J., Waters, M. J. Loss of growth hormone-mediated signal transducer and activator of transcription 5 (STAT5) signaling in mice results in insulin sensitivity with obesity.
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Affiliation(s)
- Yash Chhabra
- University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Caroline N Nelson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Monika Plescher
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Johanna L Barclay
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia
| | - Aaron G Smith
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia
| | - Sof Andrikopoulos
- Department of Medicine, The University of Melbourne, Victoria, Australia
| | | | - David J Waxman
- Department of Biology and Bioinformatics Program, Boston University, Boston, Massachusetts, USA
| | - Andrew J Brooks
- University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Michael J Waters
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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Bartke A. Growth Hormone and Aging: Updated Review. World J Mens Health 2018; 37:19-30. [PMID: 29756419 PMCID: PMC6305861 DOI: 10.5534/wjmh.180018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/05/2018] [Accepted: 03/05/2018] [Indexed: 01/28/2023] Open
Abstract
Role of growth hormone (GH) in mammalian aging is actively explored in clinical, epidemiological, and experimental studies. The age-related decline in GH levels is variously interpreted as a symptom of neuroendocrine aging, as one of causes of altered body composition and other unwelcome symptoms of aging, or as a mechanism of natural protection from cancer and other chronic diseases. Absence of GH signals due to mutations affecting anterior pituitary development, GH secretion, or GH receptors produces an impressive extension of longevity in laboratory mice. Extension of healthspan in these animals and analysis of survival curves suggest that in the absence of GH, aging is slowed down or delayed. The corresponding endocrine syndromes in the human have no consistent impact on longevity, but are associated with remarkable protection from age-related disease. Moreover, survival to extremely old age has been associated with reduced somatotropic (GH and insulin-like growth factor-1) signaling in women and men. In both humans and mice, elevation of GH levels into the supranormal (pathological) range is associated with increased disease risks and reduced life expectancy likely representing acceleration of aging. The widely advertised potential of GH as an anti-aging agent attracted much interest. However, results obtained thus far have been disappointing with few documented benefits and many troublesome side effects. Possible utility of GH in the treatment of sarcopenia and frailty remains to be explored.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, USA.
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6
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Basu R, Qian Y, Kopchick JJ. MECHANISMS IN ENDOCRINOLOGY: Lessons from growth hormone receptor gene-disrupted mice: are there benefits of endocrine defects? Eur J Endocrinol 2018; 178:R155-R181. [PMID: 29459441 DOI: 10.1530/eje-18-0018] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 02/19/2018] [Indexed: 12/12/2022]
Abstract
Growth hormone (GH) is produced primarily by anterior pituitary somatotroph cells. Numerous acute human (h) GH treatment and long-term follow-up studies and extensive use of animal models of GH action have shaped the body of GH research over the past 70 years. Work on the GH receptor (R)-knockout (GHRKO) mice and results of studies on GH-resistant Laron Syndrome (LS) patients have helped define many physiological actions of GH including those dealing with metabolism, obesity, cancer, diabetes, cognition and aging/longevity. In this review, we have discussed several issues dealing with these biological effects of GH and attempt to answer the question of whether decreased GH action may be beneficial.
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Affiliation(s)
- Reetobrata Basu
- Edison Biotechnology Institute, Ohio University, Athens, Ohio, USA
| | - Yanrong Qian
- Edison Biotechnology Institute, Ohio University, Athens, Ohio, USA
| | - John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, Ohio, USA
- Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
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7
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Somatic growth, aging, and longevity. NPJ Aging Mech Dis 2017; 3:14. [PMID: 28970944 PMCID: PMC5622030 DOI: 10.1038/s41514-017-0014-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 09/06/2017] [Accepted: 09/13/2017] [Indexed: 02/01/2023] Open
Abstract
Although larger species of animals typically live longer than smaller species, the relationship of body size to longevity within a species is generally opposite. The longevity advantage of smaller individuals can be considerable and is best documented in laboratory mice and in domestic dogs. Importantly, it appears to apply broadly, including humans. It is not known whether theses associations represent causal links between various developmental and physiological mechanisms affecting growth and/or aging. However, variations in growth hormone (GH) signaling are likely involved because GH is a key stimulator of somatic growth, and apparently also exerts various “pro-aging” effects. Mechanisms linking GH, somatic growth, adult body size, aging, and lifespan likely involve target of rapamycin (TOR), particularly one of its signaling complexes, mTORC1, as well as various adjustments in mitochondrial function, energy metabolism, thermogenesis, inflammation, and insulin signaling. Somatic growth, aging, and longevity are also influenced by a variety of hormonal and nutritional signals, and much work will be needed to answer the question of why smaller individuals may be likely to live longer.
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8
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Hascup KN, Lynn MK, Fitzgerald PJ, Randall S, Kopchick JJ, Boger HA, Bartke A, Hascup ER. Enhanced Cognition and Hypoglutamatergic Signaling in a Growth Hormone Receptor Knockout Mouse Model of Successful Aging. J Gerontol A Biol Sci Med Sci 2017; 72:329-337. [PMID: 27208894 DOI: 10.1093/gerona/glw088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 04/25/2016] [Indexed: 01/19/2023] Open
Abstract
Growth hormone receptor knockout (GHR-KO) mice are long lived with improved health span, making this an excellent model system for understanding biochemical mechanisms important to cognitive reserve. The purpose of the present study was to elucidate differences in cognition and glutamatergic dynamics between aged (20- to 24-month-old) GHR-KO and littermate controls. Glutamate plays a critical role in hippocampal learning and memory and is implicated in several neurodegenerative disorders, including Alzheimer's disease. Spatial learning and memory were assessed using the Morris water maze (MWM), whereas independent dentate gyrus (DG), CA3, and CA1 basal glutamate, release, and uptake measurements were conducted in isoflurane anesthetized mice utilizing an enzyme-based microelectrode array (MEA) coupled with constant potential amperometry. These MEAs have high temporal and low spatial resolution while causing minimal damage to the surrounding parenchyma. Littermate controls performed worse on the memory portion of the MWM behavioral task and had elevated DG, CA3, and CA1 basal glutamate and stimulus-evoked release compared with age-matched GHR-KO mice. CA3 basal glutamate negatively correlated with MWM performance. These results support glutamatergic regulation in learning and memory and may have implications for therapeutic targets to delay the onset of, or reduce cognitive decline, in Alzheimer's disease.
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Affiliation(s)
- Kevin N Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - Mary K Lynn
- Department of Neuroscience, Medical University of South Carolina, Charleston
| | - Patrick J Fitzgerald
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - Shari Randall
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield
| | - John J Kopchick
- Edison Biotechnology Institute, Department of Biomedical Sciences, Ohio University, Athens
| | - Heather A Boger
- Department of Neuroscience, Medical University of South Carolina, Charleston.,Center on Aging, Medical University of South Carolina, Charleston
| | | | - Erin R Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield.,Department of Pharmacology, Southern Illinois University School of Medicine, Springfield
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9
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Differential effects of early-life nutrient restriction in long-lived GHR-KO and normal mice. GeroScience 2017; 39:347-356. [PMID: 28523599 DOI: 10.1007/s11357-017-9978-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023] Open
Abstract
There is increasing evidence that growth hormone (GH) and insulin-like growth factor 1 (IGF-1) signaling (collectively referred to as somatotropic signaling) during development has a profound influence on aging and longevity. Moreover, the absence of GH action was shown to modify responses of adult mice to calorie restriction (CR) and other antiaging interventions. It was therefore of interest to determine whether GH resistance in GH receptor knockout (GHR-KO) mice would modify the effects of mild pre-weaning CR imposed by increasing the number of pups in a litter (the so-called litter crowding). In addition to the expected impact on body weight, litter crowding affected glucose homeostasis, hepatic expression of IGF-1 and genes related to lipid metabolism, and expression of inflammatory markers in white adipose tissue, with some of these effects persisting until the age of 2 years. Litter crowding failed to further extend the remarkable longevity of GHR-KO mice and, instead, reduced late life survival of GHR-KO females, an effect opposite to the changes detected in normal animals. We conclude that the absence of GH actions alters the responses to pre-weaning CR and prevents this intervention from extending longevity.
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10
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Hjortebjerg R, Berryman DE, Comisford R, Frank SJ, List EO, Bjerre M, Frystyk J, Kopchick JJ. Insulin, IGF-1, and GH Receptors Are Altered in an Adipose Tissue Depot-Specific Manner in Male Mice With Modified GH Action. Endocrinology 2017; 158:1406-1418. [PMID: 28323915 PMCID: PMC5460824 DOI: 10.1210/en.2017-00084] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 02/22/2017] [Indexed: 12/28/2022]
Abstract
Growth hormone (GH) is a determinant of glucose homeostasis and adipose tissue (AT) function. Using 7-month-old transgenic mice expressing the bovine growth hormone (bGH) gene and growth hormone receptor knockout (GHR-/-) mice, we examined whether changes in GH action affect glucose, insulin, and pyruvate tolerance and AT expression of proteins involved in the interrelated signaling pathways of GH, insulinlike growth factor 1 (IGF-1), and insulin. Furthermore, we searched for AT depot-specific differences in control mice. Glycated hemoglobin levels were reduced in bGH and GHR-/- mice, and bGH mice displayed impaired gluconeogenesis as judged by pyruvate tolerance testing. Serum IGF-1 was elevated by 90% in bGH mice, whereas IGF-1 and insulin were reduced by 97% and 61% in GHR-/- mice, respectively. Igf1 RNA was increased in subcutaneous, epididymal, retroperitoneal, and brown adipose tissue (BAT) depots in bGH mice (mean increase ± standard error of the mean in all five depots, 153% ± 27%) and decreased in all depots in GHR-/- mice (mean decrease, 62% ± 4%). IGF-1 receptor expression was decreased in all AT depots of bGH mice (mean decrease, 49% ± 6%) and increased in all AT depots of GHR-/- mice (mean increase, 94% ± 8%). Insulin receptor expression was reduced in retroperitoneal, mesenteric, and BAT depots in bGH mice (mean decrease in all depots, 56% ± 4%) and augmented in subcutaneous, retroperitoneal, mesenteric, and BAT depots in GHR-/- mice (mean increase: 51% ± 1%). Collectively, our findings indicate a role for GH in influencing hormone signaling in AT in a depot-dependent manner.
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Affiliation(s)
- Rikke Hjortebjerg
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, 8000 Aarhus, Denmark
- Danish Diabetes Academy, 5000 Odense, Denmark
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701
| | - Darlene E. Berryman
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701
- The Diabetes Institute at Ohio University, Ohio University, Athens, Ohio 45701
| | - Ross Comisford
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701
- The Diabetes Institute at Ohio University, Ohio University, Athens, Ohio 45701
| | - Stuart J. Frank
- Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama 35924
- Medical Service, Birmingham Veterans Affairs Medical Center, Birmingham, Alabama 35233
| | - Edward O. List
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701
| | - Mette Bjerre
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, 8000 Aarhus, Denmark
| | - Jan Frystyk
- Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University, 8000 Aarhus, Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, 8000 Aarhus, Denmark
| | - John J. Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701
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11
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Stout MB, Swindell WR, Zhi X, Rohde K, List EO, Berryman DE, Kopchick JJ, Gesing A, Fang Y, Masternak MM. Transcriptome profiling reveals divergent expression shifts in brown and white adipose tissue from long-lived GHRKO mice. Oncotarget 2016; 6:26702-15. [PMID: 26436954 PMCID: PMC4694946 DOI: 10.18632/oncotarget.5760] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 08/29/2015] [Indexed: 12/24/2022] Open
Abstract
Mice lacking the growth hormone receptor (GHRKO) exhibit improved lifespan and healthspan due to loss of growth hormone signaling. Both the distribution and activity of brown and white adipose tissue (BAT and WAT) are altered in GHRKO mice, but the contribution of each tissue to age-related phenotypes has remained unclear. We therefore used whole-genome microarrays to evaluate transcriptional differences in BAT and WAT depots between GHRKO and normal littermates at six months of age. Our findings reveal a unique BAT transcriptome as well as distinctive responses of BAT to Ghr ablation. BAT from GHRKO mice exhibited elevated expression of genes associated with mitochondria and metabolism, along with reduced expression of genes expressed by monocyte-derived cells (dendritic cells [DC] and macrophages). Largely the opposite was observed in WAT, with increased expression of DC-expressed genes and reduced expression of genes associated with metabolism, cellular respiration and the mitochondrial inner envelope. These findings demonstrate divergent response patterns of BAT and WAT to loss of GH signaling in GHRKO mice. These patterns suggest both BAT and WAT contribute in different ways to phenotypes in GHRKO mice, with Ghr ablation blunting inflammation in BAT as well as cellular metabolism and mitochondrial biogenesis in WAT.
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Affiliation(s)
- Michael B Stout
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | | | - Xu Zhi
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.,College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA
| | - Kyle Rohde
- College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA
| | - Edward O List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Darlene E Berryman
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - John J Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Adam Gesing
- Department of Oncological Endocrinology, Medical University of Lodz, Lodz, Poland
| | - Yimin Fang
- Geriatrics Research Laboratory, Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Michal M Masternak
- College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA.,Department of Head and Neck Surgery, The Greater Poland Cancer Centre, Poznan, Poland
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12
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Balasubramanian P, Longo VD. Growth factors, aging and age-related diseases. Growth Horm IGF Res 2016; 28:66-68. [PMID: 26883276 PMCID: PMC5455771 DOI: 10.1016/j.ghir.2016.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 12/18/2015] [Accepted: 01/04/2016] [Indexed: 12/27/2022]
Abstract
Simple organisms including yeast and flies with mutations in the IGF-1 and Tor-S6K pathways are dwarfs, are highly protected from toxins, and survive up to 3 times longer. Similarly, dwarf mice with deficiencies in the growth hormone-IGF-I axis are also long lived and protected from diseases. We recently reported that humans with Growth Hormone Receptor Deficiency (GHRD) rarely develop cancer or diabetes. These findings are in agreement with the effect of defects in the Tor-S6K pathways in causing dwarfism and protection of DNA. Because protein restriction reduces both GHR-IGF-1 axis and Tor-S6K activity, we examined links between protein intake, disease, and mortality in over 6000 US subjects in the NHANES CDC database. Respondents aged 50-65 reporting a high protein intake displayed an increase in IGF-I levels, a 75% increased risk of overall mortality and a 3-4 fold increased risk of cancer mortality in agreement with findings in mouse experiments. These studies point to a conserved link between proteins and amino acids, GHR-IGF-1/insulin, Tor-S6k signaling, aging, and diseases.
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Affiliation(s)
- Priya Balasubramanian
- Longevity Institute, Davis School of Gerontology, University of Southern California, Los Angeles, California, United States
| | - Valter D Longo
- Longevity Institute, Davis School of Gerontology, University of Southern California, Los Angeles, California, United States; IFOM, FIRC Institute of Molecular Oncology, Milano, Italy.
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13
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Bartke A. Healthspan and longevity can be extended by suppression of growth hormone signaling. Mamm Genome 2016; 27:289-99. [PMID: 26909495 DOI: 10.1007/s00335-016-9621-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/03/2016] [Indexed: 12/11/2022]
Abstract
Average and maximal lifespan are important biological characteristics of every species, but can be modified by mutations and by a variety of genetic, dietary, environmental, and pharmacological interventions. Mutations or disruption of genes required for biosynthesis or action of growth hormone (GH) produce remarkable extension of longevity in laboratory mice. Importantly, the long-lived GH-related mutants exhibit many symptoms of delayed and/or slower aging, including preservation of physical and cognitive functions and resistance to stress and age-related disease. These characteristics could be collectively described as "healthy aging" or extension of the healthspan. Extension of both the healthspan and lifespan in GH-deficient and GH-resistant mice appears to be due to multiple interrelated mechanisms. Some of these mechanisms have been linked to healthy aging and genetic predisposition to extended longevity in humans. Enhanced insulin sensitivity combined with reduced insulin levels, reduced adipose tissue, central nervous system inflammation, and increased levels of adiponectin represent such mechanisms. Further progress in elucidation of mechanisms that link reduced GH action to delayed and healthy aging should identify targets for lifestyle and pharmacological interventions that could benefit individuals as well as society.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois School of Medicine, Springfield, IL, USA.
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14
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Do A, Menon V, Zhi X, Gesing A, Wiesenborn DS, Spong A, Sun L, Bartke A, Masternak MM. Thyroxine modifies the effects of growth hormone in Ames dwarf mice. Aging (Albany NY) 2016; 7:241-55. [PMID: 25935838 PMCID: PMC4429089 DOI: 10.18632/aging.100739] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Ames dwarf (df/df) mice lack growth hormone (GH), thyroid stimulating hormone and prolactin. Treatment of juvenile df/df mice with GH alone stimulates somatic growth, reduces insulin sensitivity and shortens lifespan. Early‐life treatment with thyroxine (T4) alone produces modest growth stimulation but does not affect longevity. In this study, we examined the effects of treatment of juvenile Ames dwarf mice with a combination of GH + T4 and compared them to the effects of GH alone. Treatment of female and male dwarfs with GH + T4 between the ages of 2 and 8 weeks rescued somatic growth yet did not reduce lifespan to match normal controls, thus contrasting with the previously reported effects of GH alone. While the male dwarf GH + T4 treatment group had no significant effect on lifespan, the female dwarfs undergoing treatment showed a decrease in maximal longevity. Expression of genes related to GH and insulin signaling in the skeletal muscle and white adipose tissue (WAT) of female dwarfs was differentially affected by treatment with GH + T4 vs. GH alone. Differences in the effects of GH + T4 vs. GH alone on insulin target tissues may contribute to the differential effects of these treatments on longevity.
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Affiliation(s)
- Andrew Do
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Vinal Menon
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.,Department of Cell Biology and Anatomy, School of Medicine, University of South Carolina Columbia, SC 29209, USA
| | - Xu Zhi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.,Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China
| | - Adam Gesing
- Department of Oncological Endocrinology, Medical University of Lodz, 90-752 Lodz, Poland
| | - Denise S Wiesenborn
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.,Department of Medical Biochemistry and Molecular Biology, University of Saarland, 66421 Homburg, Germany.,Department of Biotechnology, University of Applied Sciences Kaiserslautern, 66482 Zweibrücken, Germany
| | - Adam Spong
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
| | - Liou Sun
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
| | - Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
| | - Michal M Masternak
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA.,Department of Head and Neck Surgery, The Greater Poland Cancer Centre, 61-866 Poznan, Poland
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15
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List EO, Berryman DE, Ikeno Y, Hubbard GB, Funk K, Comisford R, Young JA, Stout MB, Tchkonia T, Masternak MM, Bartke A, Kirkland JL, Miller RA, Kopchick JJ. Removal of growth hormone receptor (GHR) in muscle of male mice replicates some of the health benefits seen in global GHR-/- mice. Aging (Albany NY) 2015; 7:500-12. [PMID: 26233957 PMCID: PMC4543039 DOI: 10.18632/aging.100766] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 06/20/2015] [Indexed: 05/01/2023]
Abstract
Global disruption of the GH receptor in mice (GHR-/-) produces a large and reproducible extension in lifespan. Since lack of GH action in muscle resulting in improved glucose homeostasis is potentially a mechanism by which GHR-/- mice are long-lived, and since no information on muscle-specific GHR disruption in females is available, we generated and characterized a line of muscle-specific GHR disrupted (MuGHRKO) mice. As expected, male MuGHRKO mice had improved fasting blood glucose, insulin, c-peptide, and glucose tolerance. In contrast, female MuGHRKO mice exhibited normal glucose, insulin, and glucose tolerance. Body weight was mildly but significantly altered in opposite directions in males (decreased) and females (increased) compared to controls. Grip strength and treadmill endurance were unchanged with advanced age in both sexes, suggesting that the direct action of GH on muscle has minimal effect on age-related musculoskeletal frailty. Longevity was unchanged in both sexes at Ohio University and significantly increased for males at University of Michigan. These data suggest that removal of GHR in muscle of male MuGHRKO mice replicates some of the health benefits seen in global GHR-/- mice including improvements to glucose homeostasis and smaller body weight in males, which may explain the trends observed in lifespan.
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Affiliation(s)
- Edward O. List
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
- Department of Specialty Medicine, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Darlene E. Berryman
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
- School of Applied Health Sciences and Wellness, Ohio University, Athens, OH 45701, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Yuji Ikeno
- The Barshop Institute for Longevity and Aging Studies, San Antonio, Department of Pathology, The University of Texas Health Science Center at San Antonio, Research Service, Audie L. Murphy VA Hospital (STVHCS), San Antonio, TX 78229, USA
| | - Gene B. Hubbard
- The Barshop Institute for Longevity and Aging Studies, San Antonio, Department of Pathology, The University of Texas Health Science Center at San Antonio, Research Service, Audie L. Murphy VA Hospital (STVHCS), San Antonio, TX 78229, USA
| | - Kevin Funk
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
| | - Ross Comisford
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
| | - Jonathan A. Young
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
| | - Michael B. Stout
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Tamar Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Michal M. Masternak
- College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, 32827, USA
- Department of Head and Neck Surgery, The Greater Poland Cancer Centre, Poznan, 61-866, Poland
| | - Andrzej Bartke
- Department of Internal Medicine, Geriatrics Research, Southern Illinois University School of Medicine, Springfield, IL 62702, USA
| | - James L. Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Richard A. Miller
- Department of Pathology and Geriatrics Center, University of Michigan, Ann Arbor, MI 48109, USA
| | - John J. Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, USA
- School of Applied Health Sciences and Wellness, Ohio University, Athens, OH 45701, USA
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16
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Arum O, Dawson JA, Smith DL, Kopchick JJ, Allison DB, Bartke A. Do altered energy metabolism or spontaneous locomotion 'mediate' decelerated senescence? Aging Cell 2015; 14:483-90. [PMID: 25720347 PMCID: PMC4406677 DOI: 10.1111/acel.12318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2015] [Indexed: 12/01/2022] Open
Abstract
That one or multiple measures of metabolic rate may be robustly associated with, or possibly even causative of, the progression of aging-resultant phenotypes such as lifespan is a long-standing, well-known mechanistic hypothesis. To broach this hypothesis, we assessed metabolic function and spontaneous locomotion in two genetic and one dietary mouse models for retarded aging, and subjected the data to mediation analyses to determine whether any metabolic or locomotor trait could be identified as a mediator of the effect of any of the interventions on senescence. We do not test the hypothesis of causality (which would require some experiments), but instead test whether the correlation structure of certain variables is consistent with one possible pathway model in which a proposed mediating variable has a causal role. Results for metabolic measures, including oxygen consumption and respiratory quotient, failed to support this hypothesis; similar negative results were obtained for three behavioral motion metrics. Therefore, our mediation analyses did not find support that any of these correlates of decelerated senescence was a substantial mediator of the effect of either of these genetic alterations (with or without caloric restriction) on longevity. Further studies are needed to relate the examined phenotypic characteristics to mechanisms of aging and control of longevity.
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Affiliation(s)
- Oge Arum
- Department of Internal Medicine Southern Illinois University‐School of Medicine Springfield IL 62794 USA
| | - John Alexander Dawson
- Section on Statistical Genetics Department of Biostatistics School of Public Health University of Alabama at Birmingham 1665 University Blvd RPHB 140J Birmingham AL 35294‐0022 USA
| | - Daniel Larry Smith
- Nutrition Obesity Research Center Department of Nutrition Sciences University of Alabama at Birmingham Birmingham AL 35294‐0022 USA
| | - John J. Kopchick
- Department of Biomedical Sciences Edison Biotechnology Institute Heritage College of Osteopathic Medicine Ohio University Athens OH 45701 USA
| | - David B. Allison
- Section on Statistical Genetics Department of Biostatistics School of Public Health University of Alabama at Birmingham 1665 University Blvd RPHB 140J Birmingham AL 35294‐0022 USA
- Nutrition Obesity Research Center Department of Nutrition Sciences University of Alabama at Birmingham Birmingham AL 35294‐0022 USA
| | - Andrzej Bartke
- Department of Internal Medicine Southern Illinois University‐School of Medicine Springfield IL 62794 USA
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17
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Hascup ER, Wang F, Kopchick JJ, Bartke A. Inflammatory and Glutamatergic Homeostasis Are Involved in Successful Aging. J Gerontol A Biol Sci Med Sci 2015; 71:281-9. [PMID: 25711529 DOI: 10.1093/gerona/glv010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 01/10/2015] [Indexed: 11/13/2022] Open
Abstract
Whole body studies using long-lived growth hormone receptor gene disrupted or knock out (GHR-KO) mice report global GH resistance, increased insulin sensitivity, reduced insulin-like growth factor 1 (IGF-1), and cognitive retention in old-age, however, little is known about the neurobiological status of these mice. The aim of this study was to determine if glutamatergic and inflammatory markers that are altered in aging and/or age-related diseases and disorders, are preserved in mice that experience increased healthspan. We examined messenger ribonucleic acid (mRNA) expression levels in the brain of 4- to 6-, 8- to 10-, and 20- to 22-month GHR-KO and normal aging control mice. In the hippocampus, glutamate transporter 1 (GLT-1) and anti-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB)-p50 were elevated in 8- to 10-month GHR-KO mice compared with age-matched controls. In the hypothalamus, NFκB-p50, NFκB-p65, IGF-1 receptor (IGF-1R), glutamate/aspartate transporter (GLAST), and 2-amino-3-(5-methyl-3-oxo 2,3-dihydro-1,2 oxazol-4-yl) propanoic acid receptor subunit 1 (GluA1) were elevated in 8- to 10- and/or 20- to 22-month GHR-KO mice when comparing genotypes. Finally, interleukin 1-beta (IL-1β) mRNA was reduced in 4- to 6- and/or 8- to 10-month GHR-KO mice compared with normal littermates in all brain areas examined. These data support the importance of decreased brain inflammation in early adulthood and maintained homeostasis of the glutamatergic and inflammatory systems in extended longevity.
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Affiliation(s)
- Erin R Hascup
- Department of Neurology and the Center for Alzheimer's Disease and Related Disorders, Southern Illinois University School of Medicine, Springfield.
| | - Feiya Wang
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield
| | - John J Kopchick
- Edison Biotechnology Institute Department of Biomedical Sciences, Ohio University, Athens
| | - Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield
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18
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Brown-Borg HM, Rakoczy SG, Wonderlich JA, Rojanathammanee L, Kopchick JJ, Armstrong V, Raasakka D. Growth hormone signaling is necessary for lifespan extension by dietary methionine. Aging Cell 2014; 13:1019-27. [PMID: 25234161 PMCID: PMC4244257 DOI: 10.1111/acel.12269] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2014] [Indexed: 11/29/2022] Open
Abstract
Growth hormone significantly impacts lifespan in mammals. Mouse longevity is extended when growth hormone (GH) signaling is interrupted but markedly shortened with high-plasma hormone levels. Methionine metabolism is enhanced in growth hormone deficiency, for example, in the Ames dwarf, but suppressed in GH transgenic mice. Methionine intake affects also lifespan, and thus, GH mutant mice and respective wild-type littermates were fed 0.16%, 0.43%, or 1.3% methionine to evaluate the interaction between hormone status and methionine. All wild-type and GH transgenic mice lived longer when fed 0.16% methionine but not when fed higher levels. In contrast, animals without growth hormone signaling due to hormone deficiency or resistance did not respond to altered levels of methionine in terms of lifespan, body weight, or food consumption. Taken together, our results suggest that the presence of growth hormone is necessary to sense dietary methionine changes, thus strongly linking growth and lifespan to amino acid availability.
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Affiliation(s)
- Holly M Brown-Borg
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
| | - Sharlene G Rakoczy
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
| | - Joseph A Wonderlich
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
| | - Lalida Rojanathammanee
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
| | - John J Kopchick
- Department of Biomedical Sciences Heritage College of Osteopathic Medicine, Edison Biotechnology Institute, Ohio UniversityAthens, OH, 45701, USA
| | - Vanessa Armstrong
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
| | - Debbie Raasakka
- Department of Basic Sciences, University of North Dakota School of Medicine and Health SciencesGrand Forks, ND, 58203, USA
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19
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Rojanathammanee L, Rakoczy S, Kopchick J, Brown-Borg HM. Effects of insulin-like growth factor 1 on glutathione S-transferases and thioredoxin in growth hormone receptor knockout mice. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9687. [PMID: 25001375 PMCID: PMC4150915 DOI: 10.1007/s11357-014-9687-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 06/27/2014] [Indexed: 05/19/2023]
Abstract
Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) have been shown to affect processes involved in cellular stress defense, aging, and longevity. This study was designed to identify possible mechanisms of a disrupted GH signaling pathway on stress resistance using growth hormone receptor knockout (GHRKO) mice. GHRKO mice are GH resistant due to the targeted disruption of the GH receptor/binding protein gene, thus preventing GH from binding and exerting its downstream effects. These mice have very low circulating IGF-1 levels and high GH levels, are obese yet insulin sensitive, and live longer than their wild-type controls. Wild-type or GHRKO mice were treated with saline or IGF-1 (WT saline, GHRKO saline, GHRKO IGF-1) two times daily for 7 days. Glutathione S-transferase (GST) activities, proteins, and gene expression were determined. Liver mitochondrial GSTA1, GSTA3, and GSTZ1 proteins were significantly higher in GHRKO when compared to those of WT mice. The 4-hydroxynonenal (4-HNE) GST activity was upregulated in GHRKO mice and was suppressed after IGF-1 administration. Interestingly, thioredoxin (Trx)1, Trx2, thioredoxin reductase (TrxR)1, and TrxR2 messenger RNA (mRNA) levels were significantly higher in the GHRKO as compared to WT mice, and IGF-1 treatment suppressed the expression of each. We also found that glutaredoxin (Grx)2 mRNA and cytosolic Grx activity were higher in GHRKO mice. These results suggest that the detoxification and stress response mechanisms in GHRKO mice are contributed in part by the circulating level of IGF-1.
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Affiliation(s)
- Lalida Rojanathammanee
- />Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, School of Medicine and Health Sciences, 501 North Columbia Road, Grand Forks, ND 58203 USA
- />School of Sports Science, Institute of Science, Suranaree University of Technology, Muang District, Nakhon Ratchasima, 30000 Thailand
| | - Sharlene Rakoczy
- />Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, School of Medicine and Health Sciences, 501 North Columbia Road, Grand Forks, ND 58203 USA
| | - John Kopchick
- />Edison Biotechnology Institute, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701 USA
| | - Holly M. Brown-Borg
- />Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, School of Medicine and Health Sciences, 501 North Columbia Road, Grand Forks, ND 58203 USA
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20
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Arum O, Saleh JK, Boparai RK, Kopchick JJ, Khardori RK, Bartke A. Preservation of blood glucose homeostasis in slow-senescing somatotrophism-deficient mice subjected to intermittent fasting begun at middle or old age. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9651. [PMID: 24789008 PMCID: PMC4082609 DOI: 10.1007/s11357-014-9651-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/26/2014] [Indexed: 05/19/2023]
Abstract
Poor blood glucose homeostatic regulation is common, consequential, and costly for older and elderly populations, resulting in pleiotrophically adverse clinical outcomes. Somatotrophic signaling deficiency and dietary restriction have each been shown to delay the rate of senescence, resulting in salubrious phenotypes such as increased survivorship. Using two growth hormone (GH) signaling-related, slow-aging mouse mutants we tested, via longitudinal analyses, whether genetic perturbations that increase survivorship also improve blood glucose homeostatic regulation in senescing mammals. Furthermore, we institute a dietary restriction paradigm that also decelerates aging, an intermittent fasting (IF) feeding schedule, as either a short-term or a sustained intervention beginning at either middle or old age, and assess its effects on blood glucose control. We find that either of the two genetic alterations in GH signaling ameliorates fasting hyperglycemia; additionally, both longevity-inducing somatotrophic mutations improve insulin sensitivity into old age. Strikingly, we observe major and broad improvements in blood glucose homeostatic control by IF: IF improves ad libitum-fed hyperglycemia, glucose tolerance, and insulin sensitivity, and reduces hepatic gluconeogenesis, in aging mutant and normal mice. These results on correction of aging-resultant blood glucose dysregulation have potentially important clinical and public health implications for our ever-graying global population, and are consistent with the Longevity Dividend concept.
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Affiliation(s)
- Oge Arum
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, 62794, USA,
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21
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Kopchick JJ, List EO, Kelder B, Gosney ES, Berryman DE. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications. Mol Cell Endocrinol 2014; 386:34-45. [PMID: 24035867 PMCID: PMC3943600 DOI: 10.1016/j.mce.2013.09.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/29/2013] [Accepted: 09/03/2013] [Indexed: 11/28/2022]
Abstract
The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant's preclinical and clinical trials, and provide data suggesting pegvisomant's therapeutic value in selected types of cancer.
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Affiliation(s)
- John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, United States; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, United States.
| | - Edward O List
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, United States; Department of Specialty Medicine, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, United States
| | - Bruce Kelder
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, United States; Department of Pediatrics, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, United States
| | - Elahu S Gosney
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, United States
| | - Darlene E Berryman
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701, United States; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, United States; School of Applied Health Sciences and Wellness, Ohio University, Athens, OH 45701, United States
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22
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Recinella L, Shohreh R, Salvatori R, Orlando G, Vacca M, Brunetti L. Effects of isolated GH deficiency on adipose tissue, feeding and adipokines in mice. Growth Horm IGF Res 2013; 23:237-242. [PMID: 24021480 DOI: 10.1016/j.ghir.2013.08.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/30/2013] [Accepted: 08/20/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Growth hormone deficiency (GHD) leads to growth failure and changes in body composition including increased fat accumulation and reduced lean body mass in both humans and rodents. The aim of this study was to characterize the consequences of isolated GHD (IGHD) on adiposity, total body weight (TBW), and food intake in a mouse model of autosomal recessive IGHD due to targeted ablation of the GH-releasing hormone (GHRH) gene [GHRH knockout (GHRHKO)]. Animals were also analyzed with respect to leptin, adiponectin and visfatin circulating levels and gene expression in both intra-abdominal and subcutaneous fat. DESIGN We studied 8 male mice homozygous for GHRHKO allele (-/-) and 8 heterozygous (+/-) animals as controls. Feeding and TBW data were collected weekly from 3 through 5 months of age. Animals were then euthanized for measurement of body length and intra-abdominal (epididymal and retroperitoneal) and subcutaneous (interscapular, axillary, gluteal and inguinal) fat weights, and for blood collection for leptin, adiponectin and visfatin measurement. Gene expression of leptin, adiponectin and visfatin in adipose tissue was evaluated by real-time reverse transcription polymerase chain reaction. RESULTS GHRHKO mice had significantly increased relative intra-abdominal (P<0.01) and subcutaneous (P<0.0001) fat, accompanied by significantly increased food intake per TBW (P<0.01), whereas - despite 40% higher food consumption--TBW change was not different from controls over the 2 month period. Adiponectin and visfatin mRNA levels were decreased in both intra-abdominal (P<0.001) and subcutaneous fat (P<0.0001), while leptin mRNA levels were not different from controls. Conversely, serum adiponectin levels were higher in GHRHKO mice (P<0.0001), whereas serum visfatin and leptin did not significantly differ from controls. CONCLUSIONS IGHD due to targeted ablation of the GHRH gene in mice is associated with increased relative subcutaneous and intra-abdominal fat mass and higher food consumption which is not related to changes in circulating leptin.
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Affiliation(s)
- Lucia Recinella
- Department of Pharmacy, G. d'Annunzio University, Chieti, Italy
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23
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Prevention of neuromusculoskeletal frailty in slow-aging ames dwarf mice: longitudinal investigation of interaction of longevity genes and caloric restriction. PLoS One 2013; 8:e72255. [PMID: 24155868 PMCID: PMC3796515 DOI: 10.1371/journal.pone.0072255] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/12/2013] [Indexed: 11/19/2022] Open
Abstract
Ames dwarf (Prop1df/df) mice are remarkably long-lived and exhibit many characteristics of delayed aging and extended healthspan. Caloric restriction (CR) has similar effects on healthspan and lifespan, and causes an extension of longevity in Ames dwarf mice. Our study objective was to determine whether Ames dwarfism or CR influence neuromusculoskeletal function in middle-aged (82 ± 12 weeks old) or old (128 ± 14 w.o.) mice. At the examined ages, strength was improved by dwarfism, CR, and dwarfism plus CR in male mice; balance/ motor coordination was improved by CR in old animals and in middle-aged females; and agility/ motor coordination was improved by a combination of dwarfism and CR in both genders of middle-aged mice and in old females. Therefore, extension of longevity by congenital hypopituitarism is associated with improved maintenance of the examined measures of strength, agility, and motor coordination, key elements of frailty during human aging, into advanced age. This study serves as a particularly important example of knowledge related to addressing aging-associated diseases and disorders that results from studies in long-lived mammals.
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24
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Hong SL, Longo KA, Gosney E, Kopchick JJ. Increased metabolic flexibility and complexity in a long-lived growth hormone insensitive mouse model. J Gerontol A Biol Sci Med Sci 2013; 69:274-81. [PMID: 23788654 DOI: 10.1093/gerona/glt090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The goal of this study was to test whether the "loss of the complexity" hypothesis can be applied to compare the metabolic patterns of mouse models with known differences in metabolic and endocrine function as well as life span. Here, we compare the complexity of locomotor activity and metabolic patterns (energy expenditure, VO₂, and respiratory quotient) of the long-lived growth hormone receptor gene deleted mice (GHR(-/-)) and their wild-type littermates. Using approximate entropy as a measure of complexity, we observed greater metabolic complexity, as indicated by greater irregularity in the physiological fluctuations of the GHR(-/-) mice. Further analysis of the data also revealed lower energy costs of locomotor activity and a stronger relationship between locomotor activity and respiratory quotient in the GHR(-/-) mice relative to controls. These findings suggest underlying differences in metabolic modulation in the GHR(-/-) mice revealed especially through measures of complexity of their time-dependent fluctuations.
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Affiliation(s)
- S Lee Hong
- Irvine Hall 246, 1 Ohio University, Athens, OH 45701.
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25
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Lubbers ER, List EO, Jara A, Sackman-Sala L, Cordoba-Chacon J, Gahete MD, Kineman RD, Boparai R, Bartke A, Kopchick JJ, Berryman DE. Adiponectin in mice with altered GH action: links to insulin sensitivity and longevity? J Endocrinol 2013; 216:363-74. [PMID: 23261955 PMCID: PMC3756886 DOI: 10.1530/joe-12-0505] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Adiponectin is positively correlated with longevity and negatively correlated with many obesity-related diseases. While there are several circulating forms of adiponectin, the high-molecular-weight (HMW) version has been suggested to have the predominant bioactivity. Adiponectin gene expression and cognate serum protein levels are of particular interest in mice with altered GH signaling as these mice exhibit extremes in obesity that are positively associated with insulin sensitivity and lifespan as opposed to the typical negative association of these factors. While a few studies have reported total adiponectin levels in young adult mice with altered GH signaling, much remains unresolved, including changes in adiponectin levels with advancing age, proportion of total adiponectin in the HMW form, adipose depot of origin, and differential effects of GH vs IGF1. Therefore, the purpose of this study was to address these issues using assorted mouse lines with altered GH signaling. Our results show that adiponectin is generally negatively associated with GH activity, regardless of age. Further, the amount of HMW adiponectin is consistently linked with the level of total adiponectin and not necessarily with previously reported lifespan or insulin sensitivity of these mice. Interestingly, circulating adiponectin levels correlated strongly with inguinal fat mass, implying that the effects of GH on adiponectin are depot specific. Interestingly, rbGH, but not IGF1, decreased circulating total and HMW adiponectin levels. Taken together, these results fill important gaps in the literature related to GH and adiponectin and question the frequently reported associations of total and HMW adiponectin with insulin sensitivity and longevity.
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Affiliation(s)
- Ellen R. Lubbers
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701
| | - Edward O. List
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701
| | - Adam Jara
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701
- Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH
| | | | | | - Manuel D. Gahete
- Jesse Brown VA Medical Center, Research and Development, Chicago IL 60612
| | - Rhonda D. Kineman
- Jesse Brown VA Medical Center, Research and Development, Chicago IL 60612
| | - Ravneet Boparai
- Southern Illinois University School of Medicine, Springfield, IL 62794
| | - Andrzej Bartke
- Southern Illinois University School of Medicine, Springfield, IL 62794
| | - John J. Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701
- Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH
| | - Darlene E. Berryman
- Edison Biotechnology Institute, Ohio University, Athens, OH 45701
- Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH
- School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH 45701
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Ungvari Z, Csiszar A. The emerging role of IGF-1 deficiency in cardiovascular aging: recent advances. J Gerontol A Biol Sci Med Sci 2012; 67:599-610. [PMID: 22451468 DOI: 10.1093/gerona/gls072] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This review focuses on cardiovascular protective effects of insulin-like growth factor (IGF)-1, provides a landscape of molecular mechanisms involved in cardiovascular alterations in patients and animal models with congenital and adult-onset IGF-1 deficiency, and explores the link between age-related IGF-1 deficiency and the molecular, cellular, and functional changes that occur in the cardiovascular system during aging. Microvascular protection conferred by endocrine and paracrine IGF-1 signaling, its implications for the pathophysiology of cardiac failure and vascular cognitive impairment, and the role of impaired cellular stress resistance in cardiovascular aging considered here are based on emerging knowledge of the effects of IGF-1 on Nrf2-driven antioxidant response.
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Affiliation(s)
- Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1303, Oklahoma City, OK 73104, USA.
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Masternak MM, Bartke A, Wang F, Spong A, Gesing A, Fang Y, Salmon AB, Hughes LF, Liberati T, Boparai R, Kopchick JJ, Westbrook R. Metabolic effects of intra-abdominal fat in GHRKO mice. Aging Cell 2012; 11:73-81. [PMID: 22040032 DOI: 10.1111/j.1474-9726.2011.00763.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Mice with targeted deletion of the growth hormone receptor (GHRKO mice) are growth hormone (GH) resistant, small, obese, hypoinsulinemic, highly insulin sensitive and remarkably long-lived. To elucidate the unexpected coexistence of adiposity with improved insulin sensitivity and extended longevity, we examined effects of surgical removal of visceral (epididymal and perinephric) fat on metabolic traits related to insulin signaling and longevity. Comparison of results obtained in GHRKO mice and in normal animals from the same strain revealed disparate effects of visceral fat removal (VFR) on insulin and glucose tolerance, adiponectin levels, accumulation of ectopic fat, phosphorylation of insulin signaling intermediates, body temperature, and respiratory quotient (RQ). Overall, VFR produced the expected improvements in insulin sensitivity and reduced body temperature and RQ in normal mice and had opposite effects in GHRKO mice. Some of the examined parameters were altered by VFR in opposite directions in GHRKO and normal mice, and others were affected in only one genotype or exhibited significant genotype × treatment interactions. Functional differences between visceral fat of GHRKO and normal mice were confirmed by measurements of adipokine secretion, lipolysis, and expression of genes related to fat metabolism. We conclude that in the absence of GH signaling, the secretory activity of visceral fat is profoundly altered and unexpectedly promotes enhanced insulin sensitivity. The apparent beneficial effects of visceral fat in GHRKO mice may also explain why reducing adiposity by calorie restriction fails to improve insulin signaling or further extend longevity in these animals.
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Affiliation(s)
- Michal M Masternak
- College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32827, USA.
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Bartke A. Pleiotropic effects of growth hormone signaling in aging. Trends Endocrinol Metab 2011; 22:437-42. [PMID: 21852148 PMCID: PMC4337825 DOI: 10.1016/j.tem.2011.07.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 06/10/2011] [Accepted: 07/11/2011] [Indexed: 01/13/2023]
Abstract
Growth hormone (GH) affects somatic growth, sexual maturation, body composition and metabolism, as well as aging and longevity. Mice lacking GH or GH receptor outlive their normal siblings and exhibit symptoms of delayed aging associated with improved insulin signaling and increased stress resistance. Beneficial effects of eliminating the actions of GH are counterintuitive but conform to the concept of antagonistic pleiotropy. Evolutionary selection for traits promoting early-life fitness and reproductive success could account for post-reproductive deficits. Reciprocal relationships between GH signaling and longevity discovered in mutant mice apply also to normal mice, other mammalian species, and perhaps humans. This review summarizes the present understanding of the multifaceted relationship between somatotropic signaling and mammalian aging.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, 801 North Rutledge, PO Box 19628, Springfield, IL 62794-9628, USA.
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29
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Bailey-Downs LC, Mitschelen M, Sosnowska D, Toth P, Pinto JT, Ballabh P, Valcarcel-Ares MN, Farley J, Koller A, Henthorn JC, Bass C, Sonntag WE, Ungvari Z, Csiszar A. Liver-specific knockdown of IGF-1 decreases vascular oxidative stress resistance by impairing the Nrf2-dependent antioxidant response: a novel model of vascular aging. J Gerontol A Biol Sci Med Sci 2011; 67:313-29. [PMID: 22021391 DOI: 10.1093/gerona/glr164] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent studies demonstrate that age-related dysfunction of NF-E2-related factor-2 (Nrf2)-driven pathways impairs cellular redox homeostasis, exacerbating age-related cellular oxidative stress and increasing sensitivity of aged vessels to oxidative stress-induced cellular damage. Circulating levels of insulin-like growth factor (IGF)-1 decline during aging, which significantly increases the risk for cardiovascular diseases in humans. To test the hypothesis that adult-onset IGF-1 deficiency impairs Nrf2-driven pathways in the vasculature, we utilized a novel mouse model with a liver-specific adeno-associated viral knockdown of the Igf1 gene using Cre-lox technology (Igf1(f/f) + MUP-iCre-AAV8), which exhibits a significant decrease in circulating IGF-1 levels (~50%). In the aortas of IGF-1-deficient mice, there was a trend for decreased expression of Nrf2 and the Nrf2 target genes GCLC, NQO1 and HMOX1. In cultured aorta segments of IGF-1-deficient mice treated with oxidative stressors (high glucose, oxidized low-density lipoprotein, and H(2)O(2)), induction of Nrf2-driven genes was significantly attenuated as compared with control vessels, which was associated with an exacerbation of endothelial dysfunction, increased oxidative stress, and apoptosis, mimicking the aging phenotype. In conclusion, endocrine IGF-1 deficiency is associated with dysregulation of Nrf2-dependent antioxidant responses in the vasculature, which likely promotes an adverse vascular phenotype under pathophysiological conditions associated with oxidative stress (eg, diabetes mellitus, hypertension) and results in accelerated vascular impairments in aging.
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Affiliation(s)
- Lora C Bailey-Downs
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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30
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List EO, Sackmann-Sala L, Berryman DE, Funk K, Kelder B, Gosney ES, Okada S, Ding J, Cruz-Topete D, Kopchick JJ. Endocrine parameters and phenotypes of the growth hormone receptor gene disrupted (GHR-/-) mouse. Endocr Rev 2011; 32:356-86. [PMID: 21123740 PMCID: PMC3365798 DOI: 10.1210/er.2010-0009] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Disruption of the GH receptor (GHR) gene eliminates GH-induced intracellular signaling and, thus, its biological actions. Therefore, the GHR gene disrupted mouse (GHR-/-) has been and is a valuable tool for helping to define various parameters of GH physiology. Since its creation in 1995, this mouse strain has been used by our laboratory and others for numerous studies ranging from growth to aging. Some of the most notable discoveries are their extreme insulin sensitivity in the presence of obesity. Also, the animals have an extended lifespan, which has generated a large number of investigations into the roles of GH and IGF-I in the aging process. This review summarizes the many results derived from the GHR-/- mice. We have attempted to present the findings in the context of current knowledge regarding GH action and, where applicable, to discuss how these mice compare to GH insensitivity syndrome in humans.
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Affiliation(s)
- Edward O List
- The Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
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31
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Tateno C, Kataoka M, Utoh R, Tachibana A, Itamoto T, Asahara T, Miya F, Tsunoda T, Yoshizato K. Growth hormone-dependent pathogenesis of human hepatic steatosis in a novel mouse model bearing a human hepatocyte-repopulated liver. Endocrinology 2011; 152:1479-91. [PMID: 21303949 DOI: 10.1210/en.2010-0953] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Clinical studies have shown a close association between nonalcoholic fatty liver disease and adult-onset GH deficiency, but the relevant molecular mechanisms are still unclear. No mouse model has been suitable to study the etiological relationship of human nonalcoholic fatty liver disease and human adult-onset GH deficiency under conditions similar to the human liver in vivo. We generated human (h-)hepatocyte chimeric mice with livers that were predominantly repopulated with h-hepatocytes in a h-GH-deficient state. The chimeric mouse liver was mostly repopulated with h-hepatocytes about 50 d after transplantation and spontaneously became fatty in the h-hepatocyte regions after about 70 d. Infusion of the chimeric mouse with h-GH drastically decreased steatosis, showing the direct cause of h-GH deficiency in the generation of hepatic steatosis. Using microarray profiles aided by real-time quantitative RT-PCR, comparison between h-hepatocytes from h-GH-untreated and -treated mice identified 14 GH-up-regulated and four GH-down-regulated genes, including IGF-I, SOCS2, NNMT, IGFLS, P4AH1, SLC16A1, SRD5A1, FADS1, and AKR1B10, respectively. These GH-up- and -down-regulated genes were expressed in the chimeric mouse liver at lower and higher levels than in human livers, respectively. Treatment of the chimeric mice with h-GH ameliorated their altered expression. h-Hepatocytes were separated from chimeric mouse livers for testing in vitro effects of h-GH or h-IGF-I on gene expression, and results showed that GH directly regulated the expression of IGF-I, SOCS2, NNMT, IGFALS, P4AH1, FADS1, and AKR1B10. In conclusion, the chimeric mouse is a novel h-GH-deficient animal model for studying in vivo h-GH-dependent human liver dysfunctions.
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Affiliation(s)
- Chise Tateno
- Yoshizato Project, Hiroshima Prefectural Institute of Industrial Science and Technology, Cooperative Link of Unique Science and Technology for Economy Revitalization, Higashihirosima, Hiroshima 739-0046, Japan
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32
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Mavalli MD, DiGirolamo DJ, Fan Y, Riddle RC, Campbell KS, van Groen T, Frank SJ, Sperling MA, Esser KA, Bamman MM, Clemens TL. Distinct growth hormone receptor signaling modes regulate skeletal muscle development and insulin sensitivity in mice. J Clin Invest 2010; 120:4007-20. [PMID: 20921627 DOI: 10.1172/jci42447] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 08/18/2010] [Indexed: 01/21/2023] Open
Abstract
Skeletal muscle development, nutrient uptake, and nutrient utilization is largely coordinated by growth hormone (GH) and its downstream effectors, in particular, IGF-1. However, it is not clear which effects of GH on skeletal muscle are direct and which are secondary to GH-induced IGF-1 expression. Thus, we generated mice lacking either GH receptor (GHR) or IGF-1 receptor (IGF-1R) specifically in skeletal muscle. Both exhibited impaired skeletal muscle development characterized by reductions in myofiber number and area as well as accompanying deficiencies in functional performance. Defective skeletal muscle development, in both GHR and IGF-1R mutants, was attributable to diminished myoblast fusion and associated with compromised nuclear factor of activated T cells import and activity. Strikingly, mice lacking GHR developed metabolic features that were not observed in the IGF-1R mutants, including marked peripheral adiposity, insulin resistance, and glucose intolerance. Insulin resistance in GHR-deficient myotubes derived from reduced IR protein abundance and increased inhibitory phosphorylation of IRS-1 on Ser 1101. These results identify distinct signaling pathways through which GHR regulates skeletal muscle development and modulates nutrient metabolism.
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Affiliation(s)
- Mahendra D Mavalli
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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33
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Le Couteur DG, Benson VL, McMahon AC, Blyth F, Handelsman DJ, Seibel MJ, Kennerson M, Naganathan V, Cumming RG, de Cabo R. Determinants of serum-induced SIRT1 expression in older men: the CHAMP study. J Gerontol A Biol Sci Med Sci 2010; 66:3-8. [PMID: 20819794 DOI: 10.1093/gerona/glq158] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Circulating factors that have an effect on SIRT1 expression are influenced by caloric restriction. To determine the association between frailty and such circulating factors, we measured serum-induced SIRT1 expression from a nested cohort of frail (n = 77) and robust (n = 82) participants from Concord Health and Ageing in Men Project, a population-based study of community-dwelling men older than 70 years. Serum-induced SIRT1 expression was not different between frail and robust men (103.1 ± 17.0 versus 100.4 ± 19.3 μg/L). However, subsequent analyses showed that men with the lowest values (first quartile) were less likely to be frail (odds ratio = 0.5, 95% confidence interval = 0.2-1.0, p = .04) and had higher total body lean mass (p = .001) than the other participants. Serum-induced SIRT1 expression did not correlate with age, diseases, medications, albumin, fasting glucose, or lipids. Overall, there was no association between frailty and serum-induced SIRT1 expression; however, post hoc analysis suggested that there might be a paradoxical association between low serum-induced SIRT1 expression and robustness.
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Affiliation(s)
- David G Le Couteur
- Centre for Education and Research on Ageing, Concord Repatriation General Hospital, University of Sydney, Hospital Road, Concord, NSW 2139, Australia.
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Swindell WR, Masternak MM, Bartke A. In vivo analysis of gene expression in long-lived mice lacking the pregnancy-associated plasma protein A (PappA) gene. Exp Gerontol 2010; 45:366-74. [PMID: 20197085 DOI: 10.1016/j.exger.2010.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/16/2010] [Accepted: 02/18/2010] [Indexed: 01/15/2023]
Abstract
Mice lacking the pregnancy-associated plasma protein A (PappA) gene exhibit diminished localized IGF-1 bioavailability and a 30% increase in mean life span. However, it is uncertain which tissues exhibit reduced IGF-1 signals in the PappA(-/-) mouse, and whether effects of this mutation parallel those of mutations that diminish IGF-1 in serum. Across a panel of 21 tissues, we used RT-PCR to evaluate the effects of the PappA(-/-) mutation on expression of Igfbp5, which served as an in vivo indicator of IGF-1 signaling. Among these tissues, expression of Igfbp5 was significantly reduced by PappA(-/-) only in kidney. A broader survey of IGF-associated genes in six organs identified five other genes responsive to PappA(-/-) in kidney, with stronger effects in this organ relative to other tissues. Renal expression of Irs1 and Mt1 was increased by PappA(-/-) as well as by mutations that reduce IGF-1 in serum (i.e., Ghr(-/-), Pit1(dw/dw) and Prop1(df/df)), and we demonstrate that expression of these genes is regulated by growth hormone-treatment and calorie restriction. These results provide in vivo data on an important new model of mammalian aging, and characterize both similar and contrasting expression patterns between long-lived mice with reduced local IGF-1 availability and diminished IGF-1 in serum.
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Affiliation(s)
- William R Swindell
- University of Michigan, Department of Pathology and Geriatrics Center, Ann Arbor, MI 48109-2200, USA.
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35
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Masternak MM, Panici JA, Wang F, Wang Z, Spong A. The effects of growth hormone (GH) treatment on GH and insulin/IGF-1 signaling in long-lived Ames dwarf mice. J Gerontol A Biol Sci Med Sci 2009; 65:24-30. [PMID: 19906822 DOI: 10.1093/gerona/glp172] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The disruption of the growth hormone (GH) axis in mice promotes insulin sensitivity and is strongly correlated with extended longevity. Ames dwarf (Prop1(df), df/df) mice are GH, prolactin (PRL), and thyrotropin (TSH) deficient and live approximately 50% longer than their normal siblings. To investigate the effects of GH on insulin and GH signaling pathways, we subjected these dwarf mice to twice-daily GH injections (6 microg/g/d) starting at the age of 2 weeks and continuing for 6 weeks. This produced the expected activation of the GH signaling pathway and stimulated somatic growth of the Ames dwarf mice. However, concomitantly with increased growth and increased production of insulinlike growth factor-1, the GH treatment strongly inhibited the insulin signaling pathway by decreasing insulin sensitivity of the dwarf mice. This suggests that improving growth of these animals may negatively affect both their healthspan and longevity by causing insulin resistance.
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Affiliation(s)
- Michal M Masternak
- Department of Internal Medicine, Geriatrics Research, Southern Illinois University School of Medicine, 801 N. Rutledge, Springfield, IL 62794-9628, USA.
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