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Franco M, Khorrami Chokami K, Albertelli M, Teti C, Cocchiara F, Gatto F, Trombetta C, Ferone D, Boschetti M. Modulatory activity of testosterone on growth pattern and IGF-1 levels in vanishing testis syndrome: a case report during 15 years of follow-up. BMC Endocr Disord 2023; 23:13. [PMID: 36631784 PMCID: PMC9835337 DOI: 10.1186/s12902-022-01258-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 12/21/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The vanishing testis syndrome (VTS), is a 46, XY disorder of sex development (46, XY DSD) and is characterized by the absence of testis in a 46, XY subject with male genitalia, gonadal dysgenesis and consequent hypergonadotropic hypogonadism. CASE PRESENTATION A young man affected by VTS has been followed up for more than 15-year in our center. The patient received different testosterone formulations, which modulated his IGF-1 levels and height velocity, depending on different stimulatory effects, mimicking pubertal spurt until achieving a final height in line with his genetic target. Exogenous testosterone, activating GH/IGF-1 system, can directly influence growth pattern. With this particular case report we demonstrate that an accurate monitoring of patients with VTS, as well as a perfect reproduction of testosterone secretion during pubertal spurt, can guarantee a normal growth and development and, consequently, a high level of quality of life in adulthood. CONCLUSION Testosterone levels act an important role during pubertal spurt in modulating the GH/IGF-1 axis, besides its well-known impact in sexual development. Very little amount of exogenous testosterone can stimulate IGF-1 secretion and provide to growth velocity the drive that characterizes the initial phases of the growth spurt.
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Affiliation(s)
- Marta Franco
- Endocrinology Unit, UOSD Azienda Ospedaliera San Camillo-Forlanini, Rome, Italy
| | - Keyvan Khorrami Chokami
- Endocrinology Unit, Department of Internal Medicine & Medical Specialties (DiMI), IRCCS Ospedale Policlinico San Martino, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Manuela Albertelli
- Endocrinology Unit, Department of Internal Medicine & Medical Specialties (DiMI), IRCCS Ospedale Policlinico San Martino, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Claudia Teti
- Endocrinology, Diabetology and Metabolic Diseases Unit, ASL1, Imperia, Italy
| | | | - Federico Gatto
- Endocrinology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Carlo Trombetta
- Department of Medicine, Surgery and Health Sciences, Urological Clinic, University of Trieste, Trieste, Italy
| | - Diego Ferone
- Endocrinology Unit, Department of Internal Medicine & Medical Specialties (DiMI), IRCCS Ospedale Policlinico San Martino, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy
| | - Mara Boschetti
- Endocrinology Unit, Department of Internal Medicine & Medical Specialties (DiMI), IRCCS Ospedale Policlinico San Martino, University of Genoa, Viale Benedetto XV, 16132, Genoa, Italy.
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Abstract
The growth plate is the cartilaginous portion of long bones where the longitudinal growth of the bone takes place. Its structure comprises chondrocytes suspended in a collagen matrix that go through several stages of maturation until they finally die, and are replaced by osteoblasts, osteoclasts, and lamellar bone.The process of endochondral ossification is coordinated by chondrocytes and a variety of humoral factors including growth hormone, parathyroid hormone, oestrogen, growth factors, cytokines, and various signalling pathways.Chondrocytes progress from a resting state to enter the phases of proliferation and hypertrophy. Under the influence of oestrogen, the proliferation of chondrocytes decreases as the resting chondrocytes are consumed. During the terminal phase of differentiation, cartilage is replaced by blood vessels and organized bone tissue, and once chondrocytes have died, the longitudinal growth of the bone ceases and the growth plate closes.The highly complex regulatory signals involved in this process are genetically determined, and genetic perturbations in any of the associated genes can result in abnormalities of bone growth. Hundreds of chondrodysplasias have been described, pointing to the complexity of the humoral control systems involved in endochondral ossification.While our knowledge of the mechanisms behind the various bone growth control systems is improving, a deeper understanding of the underlying processes could aid clinicians to better understand bone health and bone growth abnormalities. This review describes the current clinical research into the physiology of the growth plate. Cite this article: EFORT Open Rev 2020;5:498-507. DOI: 10.1302/2058-5241.5.190088.
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Affiliation(s)
- Yücel Ağırdil
- Department of Orthopaedics and Traumatology, İzzet Baysal State Hospital, Bolu, Turkey
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3
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Walser M, Svensson J, Karlsson L, Motalleb R, Åberg M, Kuhn HG, Isgaard J, Åberg ND. Growth Hormone and Neuronal Hemoglobin in the Brain-Roles in Neuroprotection and Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2020; 11:606089. [PMID: 33488521 PMCID: PMC7821093 DOI: 10.3389/fendo.2020.606089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/23/2020] [Indexed: 12/11/2022] Open
Abstract
In recent years, evidence for hemoglobin (Hb) synthesis in both animal and human brains has been accumulating. While circulating Hb originating from cerebral hemorrhage or other conditions is toxic, there is also substantial production of neuronal Hb, which is influenced by conditions such as ischemia and regulated by growth hormone (GH), insulin-like growth factor-I (IGF-I), and other growth factors. In this review, we discuss the possible functions of circulating and brain Hb, mainly the neuronal form, with respect to the neuroprotective activities of GH and IGF-I against ischemia and neurodegenerative diseases. The molecular pathways that link Hb to the GH/IGF-I system are also reviewed, although the limited number of reports on this topic suggests a need for further studies. In summary, GH and/or IGF-I appear to be significant determinants of systemic and local brain Hb concentrations through mediating responses to oxygen and metabolic demand, as part of the neuroprotective effects exerted by GH and IGF-I. The nature and quantity of the latter deserve further exploration in specific experiments.
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Affiliation(s)
- Marion Walser
- Department of Internal Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
- *Correspondence: Marion Walser,
| | - Johan Svensson
- Department of Internal Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Lars Karlsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- The Queen Silvia Children’s Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Reza Motalleb
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Maria Åberg
- Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
- School of Public Health and Community Medicine at University of Gothenburg, Gothenburg, Sweden
| | - H Georg Kuhn
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Institute for Public Health, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Jörgen Isgaard
- Department of Internal Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
- Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| | - N David Åberg
- Department of Internal Medicine, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
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4
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Possible effects of an early diagnosis and treatment in patients with growth hormone deficiency: the state of art. Ital J Pediatr 2017; 43:81. [PMID: 28915901 PMCID: PMC5603037 DOI: 10.1186/s13052-017-0402-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/11/2017] [Indexed: 01/16/2023] Open
Abstract
Growth hormone deficiency (GHD) is a relatively uncommon and heterogeneous endocrine disorder presenting in childhood with short stature. However, during the neonatal period, the metabolic effects of GHD may to require prompt replacement therapy to avoid possible life-threatening complications. An increasing amount of data suggests the importance of an early diagnosis and treatment of GHD because of its auxological, metabolic, and neurodevelopmental features with respect to the patients diagnosed and treated later in life. The available results show favourable auxological outcomes for patients with GHD diagnosed and treated with r-hGH early in life compared with those from patients with GHD who do not receive this early diagnosis and treatment. Because delayed referral for GHD diagnosis and treatment is still frequent, these results highlight the need for more attention in the diagnosis and treatment of GHD. Despite these very encouraging data regarding metabolic and neurodevelopmental features, further studies are needed to better characterize these findings. Overall, the importance of early diagnosis and treatment of GHD needs to be addressed.
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5
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Roselló-Díez A, Stephen D, Joyner AL. Altered paracrine signaling from the injured knee joint impairs postnatal long bone growth. eLife 2017; 6. [PMID: 28741471 PMCID: PMC5526667 DOI: 10.7554/elife.27210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022] Open
Abstract
Regulation of organ growth is a poorly understood process. In the long bones, the growth plates (GPs) drive elongation by generating a scaffold progressively replaced by bone. Although studies have focused on intrinsic GP regulation, classic and recent experiments suggest that local signals also modulate GP function. We devised a genetic mouse model to study extrinsic long bone growth modulation, in which injury is specifically induced in the left hindlimb, such that the right hindlimb serves as an internal control. Remarkably, when only mesenchyme cells surrounding postnatal GPs were killed, left bone growth was nevertheless reduced. GP signaling was impaired by altered paracrine signals from the knee joint, including activation of the injury response and, in neonates, dampened IGF1 production. Importantly, only the combined prevention of both responses rescued neonatal growth. Thus, we identified signals from the knee joint that modulate bone growth and could underlie establishment of body proportions. DOI:http://dx.doi.org/10.7554/eLife.27210.001 As bones grow, their size is carefully controlled and coordinated with the growth of the other organs in the body. The mechanisms that control organ size also help the body to recover from injury, and play a key role in controlling body size and proportions. Over the course of evolution, these mechanisms have likely changed to produce the distinct body sizes and proportions seen in humans and other animals. Despite their importance, it is not well understood how signals from both inside and outside an organ work together to regulate its size. In growth disorders this signaling goes wrong, which can lead to a person having unusual proportions such as a very short stature or having one leg shorter than the other. Currently, most growth disorders that affect leg proportions are treated with painful surgical procedures. Researchers would like to know how bone growth is affected by signals from the surrounding tissues because this could help them to develop new non-invasive treatments for these conditions. Long bones, for example those in the leg, grow from structures near their ends called growth plates. Roselló-Díez et al. have now engineered mice in which an injury shortly after birth caused cells in the knee in the rear left leg to die off. At the same time, the rear right leg of the mice developed as normal, allowing the growth of the two legs to be compared. Roselló-Díez et al. found that the left leg of these mice grew more slowly than the right leg, even though none of the cells in the growth plate of the left leg bone had been damaged. Further investigation revealed that this was because the injury caused an imbalance between the growth-promoting and growth-restricting signals that are produced by the fat pad and articular cartilage in the knee joint. Restoring the lost balance allowed the left leg bone to grow to a more normal length. In the future, boosting bone growth signals might provide a way to treat conditions like dwarfism or leg-length discrepancies. Understanding how different tissues influence body proportions could also help researchers to investigate how different animals evolved different body proportions. DOI:http://dx.doi.org/10.7554/eLife.27210.002
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Affiliation(s)
- Alberto Roselló-Díez
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
| | - Daniel Stephen
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
| | - Alexandra L Joyner
- Developmental Biology Program, Sloan Kettering Institute, New York, United States.,Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate Schoolof Medical Sciences, New York, United States
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6
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Utsumi T, Okada S, Izawa K, Honda Y, Nishimura G, Nishikomori R, Okano R, Kobayashi M. A Case with Spondyloenchondrodysplasia Treated with Growth Hormone. Front Endocrinol (Lausanne) 2017; 8:157. [PMID: 28740483 PMCID: PMC5502255 DOI: 10.3389/fendo.2017.00157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/22/2017] [Indexed: 11/25/2022] Open
Abstract
Spondyloenchondrodysplasia (SPENCD) is an autosomal recessive skeletal dysplasia caused by loss of function mutations in acid phosphatase 5, tartrate resistant (ACP5). Hypomorphic ACP5 mutations impair endochondral bone growth and create an interferon (INF) signature, which lead to distinctive spondylar and metaphyseal dysplasias, and extraskeletal morbidity, such as neurological involvement and immune dysregulation, respectively. We report an affected boy with novel ACP5 mutations, a splice-site mutation (736-2 A>C) and a nonsense mutation (R176X). He presented with postnatal short stature, which led to a diagnosis of partial growth hormone (GH) deficiency at 3 years of age. GH therapy was beneficial in accelerating his growth velocity. At 6 years of age, however, metaphyseal abnormalities of the knee attracted medical attention, and subsequent assessment ascertained the typical skeletal phenotype of SPENCD, brain calcifications, and an INF signature. This anecdotal experience indicates the potential efficacy of GH for growth failure in SPENCD.
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Affiliation(s)
- Takanori Utsumi
- Department of Pediatrics, Onomichi General Hospital, Hiroshima, Japan
- *Correspondence: Takanori Utsumi,
| | - Satoshi Okada
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
| | - Kazushi Izawa
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshitaka Honda
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Gen Nishimura
- Department of Pediatric Imaging, Tokyo Metropolitan Children’s Medical Center, Tokyo, Japan
| | - Ryuta Nishikomori
- Department of Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rika Okano
- Department of Pediatrics, Onomichi General Hospital, Hiroshima, Japan
| | - Masao Kobayashi
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, Hiroshima, Japan
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7
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Abstract
Skeletal muscle and bone rely on a number of growth factors to undergo development, modulate growth, and maintain physiological strength. A major player in these actions is insulin-like growth factor I (IGF-I). However, because this growth factor can directly enhance muscle mass and bone density, it alters the state of the musculoskeletal system indirectly through mechanical crosstalk between these two organ systems. Thus, there are clearly synergistic actions of IGF-I that extend beyond the direct activity through its receptor. This review will cover the production and signaling of IGF-I as it pertains to muscle and bone, the chemical and mechanical influences that arise from IGF-I activity, and the potential for therapeutic strategies based on IGF-I. This article is part of a Special Issue entitled "Muscle Bone Interactions".
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8
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Santa Maria C, Cheng Z, Li A, Wang J, Shoback D, Tu CL, Chang W. Interplay between CaSR and PTH1R signaling in skeletal development and osteoanabolism. Semin Cell Dev Biol 2016; 49:11-23. [PMID: 26688334 PMCID: PMC4761456 DOI: 10.1016/j.semcdb.2015.12.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 12/05/2015] [Indexed: 12/01/2022]
Abstract
Parathyroid hormone (PTH)-related peptide (PTHrP) controls the pace of pre- and post-natal growth plate development by activating the PTH1R in chondrocytes, while PTH maintains mineral and skeletal homeostasis by modulating calciotropic activities in kidneys, gut, and bone. The extracellular calcium-sensing receptor (CaSR) is a member of family C, G protein-coupled receptor, which regulates mineral and skeletal homeostasis by controlling PTH secretion in parathyroid glands and Ca(2+) excretion in kidneys. Recent studies showed the expression of CaSR in chondrocytes, osteoblasts, and osteoclasts and confirmed its non-redundant roles in modulating the recruitment, proliferation, survival, and differentiation of the cells. This review emphasizes the actions of CaSR and PTH1R signaling responses in cartilage and bone and discusses how these two signaling cascades interact to control growth plate development and maintain skeletal metabolism in physiological and pathological conditions. Lastly, novel therapeutic regimens that exploit interrelationship between the CaSR and PTH1R are proposed to produce more robust osteoanabolism.
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Affiliation(s)
- Christian Santa Maria
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Zhiqiang Cheng
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Alfred Li
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Jiali Wang
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Dolores Shoback
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Chia-Ling Tu
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Wenhan Chang
- Endocrine Research Unit, University of California, San Francisco, Veterans Affairs Medical Center, San Francisco, CA, USA.
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9
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Bikle DD, Tahimic C, Chang W, Wang Y, Philippou A, Barton ER. Role of IGF-I signaling in muscle bone interactions. Bone 2015; 80:79-88. [PMID: 26453498 PMCID: PMC4600536 DOI: 10.1016/j.bone.2015.04.036] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/11/2015] [Accepted: 04/22/2015] [Indexed: 12/16/2022]
Abstract
Skeletal muscle and bone rely on a number of growth factors to undergo development, modulate growth, and maintain physiological strength. A major player in these actions is insulin-like growth factor I (IGF-I). However, because this growth factor can directly enhance muscle mass and bone density, it alters the state of the musculoskeletal system indirectly through mechanical crosstalk between these two organ systems. Thus, there are clearly synergistic actions of IGF-I that extend beyond the direct activity through its receptor. This review will cover the production and signaling of IGF-I as it pertains to muscle and bone, the chemical and mechanical influences that arise from IGF-I activity, and the potential for therapeutic strategies based on IGF-I. This article is part of a Special Issue entitled "Muscle Bone Interactions".
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Affiliation(s)
- Daniel D Bikle
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Candice Tahimic
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Wenhan Chang
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Yongmei Wang
- VA Medical Center and University of California San Francisco, San Francisco, CA, USA
| | - Anastassios Philippou
- National and Kapodistrian University of Athens, Department of Physiology, Medical School, Goudi-Athens, Greece
| | - Elisabeth R Barton
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL, USA.
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10
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Sederquist B, Fernandez-Vojvodich P, Zaman F, Sävendahl L. Recent research on the growth plate: Impact of inflammatory cytokines on longitudinal bone growth. J Mol Endocrinol 2014; 53:T35-44. [PMID: 24711646 DOI: 10.1530/jme-14-0006] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Children with inflammatory diseases usually display abnormal growth patterns as well as delayed puberty. This is a result of several factors related to the disease itself, such as malnutrition, hypercortisolism, and elevated levels of pro-inflammatory cytokines. These factors in combination with glucocorticoid treatment contribute to growth retardation during chronic inflammation by systemically affecting the major regulator of growth, the GH/IGF1 axis. However, recent studies have also shown evidence of a direct effect of these factors at the growth plate level. In conditions of chronic inflammation, pro-inflammatory cytokines are upregulated and released into the circulation. The most abundant of these, tumor necrosis factor α, interleukin 1β (IL1β), and IL6, are all known to directly act on growth plate cartilage to induce apoptosis and thereby suppress bone growth. Both clinical and experimental studies have shown that growth retardation can partly be rescued when these cytokines are blocked. Therefore, therapy modulating the local actions of these cytokines may be effective for preventing growth failure in patients with chronic inflammatory disorders. In this review, we report the current knowledge of inflammatory cytokines and their role in regulating bone growth.
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Affiliation(s)
- Bettina Sederquist
- Pediatric Endocrinology Unit Q2:08Department of Women's and Children's Health, Karolinska University Hospital, SE-171 76 Stockholm, SwedenDevelopmental and Stem Cell BiologyThe Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Paola Fernandez-Vojvodich
- Pediatric Endocrinology Unit Q2:08Department of Women's and Children's Health, Karolinska University Hospital, SE-171 76 Stockholm, SwedenDevelopmental and Stem Cell BiologyThe Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Farasat Zaman
- Pediatric Endocrinology Unit Q2:08Department of Women's and Children's Health, Karolinska University Hospital, SE-171 76 Stockholm, SwedenDevelopmental and Stem Cell BiologyThe Hospital for Sick Children, University of Toronto, Toronto, Ontario, CanadaPediatric Endocrinology Unit Q2:08Department of Women's and Children's Health, Karolinska University Hospital, SE-171 76 Stockholm, SwedenDevelopmental and Stem Cell BiologyThe Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Lars Sävendahl
- Pediatric Endocrinology Unit Q2:08Department of Women's and Children's Health, Karolinska University Hospital, SE-171 76 Stockholm, SwedenDevelopmental and Stem Cell BiologyThe Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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11
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Chia DJ. Minireview: mechanisms of growth hormone-mediated gene regulation. Mol Endocrinol 2014; 28:1012-25. [PMID: 24825400 DOI: 10.1210/me.2014-1099] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
GH exerts a diverse array of physiological actions that include prominent roles in growth and metabolism, with a major contribution via stimulating IGF-1 synthesis. GH achieves its effects by influencing gene expression profiles, and Igf1 is a key transcriptional target of GH signaling in liver and other tissues. This review examines the mechanisms of GH-mediated gene regulation that begin with signal transduction pathways activated downstream of the GH receptor and continue with chromatin events at target genes and additionally encompasses the topics of negative regulation and cross talk with other cellular inputs. The transcription factor, signal transducer and activator of transcription 5b, is regarded as the major signaling pathway by which GH achieves its physiological effects, including in stimulating Igf1 gene transcription in liver. Recent studies exploring the mechanisms of how activated signal transducer and activator of transcription 5b accomplishes this are highlighted, which begin to characterize epigenetic features at regulatory domains of the Igf1 locus. Further research in this field offers promise to better understand the GH-IGF-1 axis in normal physiology and disease and to identify strategies to manipulate the axis to improve human health.
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Affiliation(s)
- Dennis J Chia
- Department of Pediatrics, Icahn School of Medicine at Mt Sinai, New York, New York 10029
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12
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Locatelli V, Bianchi VE. Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis. Int J Endocrinol 2014; 2014:235060. [PMID: 25147565 PMCID: PMC4132406 DOI: 10.1155/2014/235060] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/17/2014] [Accepted: 06/18/2014] [Indexed: 01/25/2023] Open
Abstract
Background. Growth hormone (GH) and insulin-like growth factor (IGF-1) are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone metabolism in osteopenic and osteoporotic human subjects and on bone healing in operated patients with normal GH secretion. Eighteen clinical studies considered the effect with GH treatment, fourteen studies reported the clinical effects with IGF-1 administration, and seven related to the GH/IGF-1 effect on bone healing. Results. Both GH and IGF-1 administration significantly increased bone resorption and bone formation in the most studies. GH/IGF-1 administration in patients with hip or tibial fractures resulted in increased bone healing, rapid clinical improvements. Some conflicting results were evidenced. Conclusions. GH and IGF-1 therapy has a significant anabolic effect. GH administration for the treatment of osteoporosis and bone fractures may greatly improve clinical outcome. GH interacts with sex steroids in the anabolic process. GH resistance process is considered.
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Affiliation(s)
- Vittorio Locatelli
- Department of Health Sciences, School of Medicine, University of Milano Bicocca, Milan, Italy
| | - Vittorio E. Bianchi
- Endocrinology Department, Area Vasta N. 1, Cagli, Italy
- *Vittorio E. Bianchi:
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13
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Steyn FJ, Ngo ST, Lee JD, Leong JW, Buckley AJ, Veldhuis JD, McCombe PA, Chen C, Bellingham MC. Impairments to the GH-IGF-I axis in hSOD1G93A mice give insight into possible mechanisms of GH dysregulation in patients with amyotrophic lateral sclerosis. Endocrinology 2012; 153:3735-46. [PMID: 22621959 DOI: 10.1210/en.2011-2171] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GH deficiency has been found in subjects with amyotrophic lateral sclerosis (ALS). Disrupted endocrine function could contribute to the progressive muscle loss and hypermetabolism seen in ALS. It is not possible to study all the elements of the GH-IGF-I axis in ALS patients. Consequently, it remains unclear whether dysfunctional GH secretion contributes to disease pathogenesis and why GH and IGF-I directed treatment strategies are ineffective in human ALS. The hSOD1(G93A) transgenic mouse model is useful for the detailed investigation of the pathogenesis of ALS. We report that symptomatic male hSOD1(G93A) transgenic mice exhibit a deficiency in GH secretion similar to that seen in human ALS. Further characterization of the GH-IGF-I axis in hSOD1(G93A) mice reveals central and peripheral abnormalities that are not found in wild-type age-matched controls. Specifically, we observe aberrant endogenous pulsatile GH secretion, reduced pituitary GH content, and decreased circulating levels of IGF-I, indicating global GH deficiency in hSOD1(G93A) mice. Furthermore, a reduction in the expression of the IGF-I receptor α-subunit in skeletal muscle and lumbar spinal cords of hSOD1(G93A) mice suggests impaired IGF-I signaling within these tissues. This is the first account of disrupted GH secretion in a transgenic mouse model of ALS. These observations are essential for the development of effective GH and IGF-I targeted therapies in ALS.
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Affiliation(s)
- F J Steyn
- School of Biomedical Sciences, University of Queensland, St. Lucia 4072, Australia.
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14
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Macsai CE, Hopwood B, Chung R, Foster BK, Xian CJ. Structural and molecular analyses of bone bridge formation within the growth plate injury site and cartilage degeneration at the adjacent uninjured area. Bone 2011; 49:904-12. [PMID: 21807132 DOI: 10.1016/j.bone.2011.07.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 07/14/2011] [Accepted: 07/15/2011] [Indexed: 11/22/2022]
Abstract
Injury to the growth plate is common and yet the injured cartilage is often repaired with undesirable bony tissue, leading to bone growth defects in children. Using a rat tibial growth plate injury model, our previous studies have shown sequential inflammatory, fibrogenic, osteogenic and bone maturation responses involved in the bony repair. However, it remains unclear whether there is progressive accumulation of bone within the injury site and any potential degenerative changes at the adjacent non-injured area of the growth plate. This study examined effects of growth plate injury on the structure, composition and some cellular and molecular changes at the injury site and adjacent uninjured area. Micro-CT analysis revealed that while the bone volume within the injury site at day 14 was small, the bone bridge was considerably larger at the injury site by 60 days post-injury. Interestingly, formation of bone bridges in the adjacent uninjured area was detected in 60% of injured animals at day 60. Immunohistochemical analyses revealed reduced chondrocyte proliferation (PCNA labelling) but increased apoptosis (nick translation labelling) in the adjacent uninjured area. RT-PCR analysis on adjacent uninjured growth plate tissue found increased expression of osteocalcin at day 60, differential expression of apoptosis-regulatory genes and alterations in genes associated with chondrocyte proliferation/differentiation, including Sox9 and IGF-I. Therefore, this study has demonstrated progressive changes in the structure/composition of the injury site and adjacent uninjured area and identified cellular and molecular alterations or degeneration in adjacent uninjured growth plate in response to injury.
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Affiliation(s)
- C E Macsai
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
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15
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16
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Smit LS, Meyer DJ, Argetsinger LS, Schwartz J, Carter‐Su C. Molecular Events in Growth Hormone–Receptor Interaction and Signaling. Compr Physiol 2011. [DOI: 10.1002/cphy.cp070514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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17
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Abstract
Pituitary somatotrophs secrete growth hormone (GH) into the bloodstream, to act as a hormone at receptor sites in most, if not all, tissues. These endocrine actions of circulating GH are abolished after pituitary ablation or hypophysectomy, indicating its pituitary source. GH gene expression is, however, not confined to the pituitary gland, as it occurs in neural, immune, reproductive, alimentary, and respiratory tissues and in the integumentary, muscular, skeletal, and cardiovascular systems, in which GH may act locally rather than as an endocrine. These actions are likely to be involved in the proliferation and differentiation of cells and tissues prior to the ontogeny of the pituitary gland. They are also likely to complement the endocrine actions of GH and are likely to maintain them after pituitary senescence and the somatopause. Autocrine or paracrine actions of GH are, however, sometimes mediated through different signaling mechanisms to those mediating its endocrine actions and these may promote oncogenesis. Extrapituitary GH may thus be of physiological and pathophysiological significance.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, 7-41 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada,
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18
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Tran GT, Pagkalos J, Tsiridis E, Narvani AA, Heliotis M, Mantalaris A, Tsiridis E. Growth hormone: does it have a therapeutic role in fracture healing? Expert Opin Investig Drugs 2010; 18:887-911. [PMID: 19480608 DOI: 10.1517/13543780902893069] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The role of growth hormone (GH) in augmenting fracture healing has been postulated for over half a century. GH has been shown to play a role in bone metabolism and this can be mediated directly or indirectly through IGF-I. OBJECTIVES The use of GH was evaluated as a possible therapeutic agent in augmenting fracture healing. METHOD A literature search was undertaken on GH and its effect on bone fracture healing primarily using MEDLINE/OVID (1950 to January 2009). Key words and phrases including 'growth hormone', 'insulin like growth factor', 'insulin like growth factor binding protein', 'insulin like growth factor receptor', 'fracture repair', 'bone healing', 'bone fracture', 'bone metabolism', 'osteoblast' and 'osteoclast' were used in different combinations. Manual searches of the bibliography of key papers were also undertaken. RESULTS Current evidence suggests a positive role of GH on fracture healing as demonstrated by in vitro studies on osteoblasts, osteoclasts and the crosstalk between the two. Animal studies have demonstrated a number of factors influencing the effect of GH in vivo such as dose, timing and method of administration. Application of this knowledge in humans is limited but clearly demonstrates a positive effect on fracture healing. Concern has been raised in the past regarding the safety profile of the pharmacological use of GH when used in critically ill patients. CONCLUSION The optimal dose and method of administration is still to be determined, and the safety profile of this novel use of GH needs to be investigated prior to establishing its widespread use as a fracture-healing agent.
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Affiliation(s)
- Gui Tong Tran
- University of Leeds School of Medicine, Academic Department of Trauma and Orthopaedics, Leeds General Infirmary, Great George Street, Leeds, UK
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19
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Ohlsson C, Mohan S, Sjögren K, Tivesten A, Isgaard J, Isaksson O, Jansson JO, Svensson J. The role of liver-derived insulin-like growth factor-I. Endocr Rev 2009; 30:494-535. [PMID: 19589948 PMCID: PMC2759708 DOI: 10.1210/er.2009-0010] [Citation(s) in RCA: 295] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
IGF-I is expressed in virtually every tissue of the body, but with much higher expression in the liver than in any other tissue. Studies using mice with liver-specific IGF-I knockout have demonstrated that liver-derived IGF-I, constituting a major part of circulating IGF-I, is an important endocrine factor involved in a variety of physiological and pathological processes. Detailed studies comparing the impact of liver-derived IGF-I and local bone-derived IGF-I demonstrate that both sources of IGF-I can stimulate longitudinal bone growth. We propose here that liver-derived circulating IGF-I and local bone-derived IGF-I to some extent have overlapping growth-promoting effects and might have the capacity to replace each other (= redundancy) in the maintenance of normal longitudinal bone growth. Importantly, and in contrast to the regulation of longitudinal bone growth, locally derived IGF-I cannot replace (= lack of redundancy) liver-derived IGF-I for the regulation of a large number of other parameters including GH secretion, cortical bone mass, kidney size, prostate size, peripheral vascular resistance, spatial memory, sodium retention, insulin sensitivity, liver size, sexually dimorphic liver functions, and progression of some tumors. It is clear that a major role of liver-derived IGF-I is to regulate GH secretion and that some, but not all, of the phenotypes in the liver-specific IGF-I knockout mice are indirect, mediated via the elevated GH levels. All of the described multiple endocrine effects of liver-derived IGF-I should be considered in the development of possible novel treatment strategies aimed at increasing or reducing endocrine IGF-I activity.
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Affiliation(s)
- Claes Ohlsson
- Division of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
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20
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Busby WH, Yocum SA, Rowland M, Kellner D, Lazerwith S, Sverdrup F, Yates M, Radabaugh M, Clemmons DR. Complement 1s is the serine protease that cleaves IGFBP-5 in human osteoarthritic joint fluid. Osteoarthritis Cartilage 2009; 17:547-55. [PMID: 18930415 PMCID: PMC3271436 DOI: 10.1016/j.joca.2008.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 08/26/2008] [Indexed: 02/02/2023]
Abstract
UNLABELLED Insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBPs) are trophic factors for cartilage and have been shown to be chondroprotective in animal models of osteoarthritis (OA). IGFBP-5 is degraded in joint fluid and inhibition of IGFBP-5 degradation has been shown to enhance the trophic effects of IGF-I. OBJECTIVE To determine the identity of IGFBP-5 protease activity in human OA joint fluid. METHOD OA joint fluid was purified and the purified material was analyzed by IGFBP-5 zymography. RESULTS Both crude joint fluid and purified material contained a single band of proteolytic activity that cleaved IGFBP-5. Immunoblotting of joint fluid for complement 1s (C1s) showed a band that had the same Mr estimate, e.g., 88 kDa. In gel tryptic digestion and subsequent peptide analysis by LC-MS/MS showed that the band contained human C1s. A panel of protease inhibitors was tested for their ability to inhibit IGFBP-5 cleavage by the purified protease. Three serine protease inhibitors, FUT175 and CP-143217 and CB-349547 had IC50's between 1 and 6 microM. Two other serine protease inhibitors had intermediate activity (e.g., IC50's 20-40 microM) and MMP inhibitors had no detectible activity at concentrations up to 300 microM. CONCLUSION Human OA fluid contains a serine protease that cleaves IGFBP-5. Zymography, immunoblotting and LC-MS/MS analysis indicate that C1s is the protease that accounts for this activity.
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Affiliation(s)
- Walker H. Busby
- Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC 27599
| | - Sue A. Yocum
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - Michael Rowland
- Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC 27599
| | - Debra Kellner
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - Scott Lazerwith
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - Francis Sverdrup
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - Matthew Yates
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - Melissa Radabaugh
- Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, MI 48105
| | - David R. Clemmons
- Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC 27599
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21
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Isaksson OG, Lindahl A, Nilsson A, Isgaard J. Action of growth hormone: current views. ACTA PAEDIATRICA SCANDINAVICA. SUPPLEMENT 2008; 343:12-8. [PMID: 3057803 DOI: 10.1111/j.1651-2227.1988.tb10794.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- O G Isaksson
- Department of Physiology, University of Gothenburg, Sweden
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22
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23
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Thorp BH, Jakowlew SB, Goddard C. Avian dyschondroplasia: Local deficiencies in growth factors are integral to the aetiopathogenesis. Avian Pathol 2007; 24:135-48. [DOI: 10.1080/03079459508419054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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24
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Clemmons DR. Modifying IGF1 activity: an approach to treat endocrine disorders, atherosclerosis and cancer. Nat Rev Drug Discov 2007; 6:821-33. [PMID: 17906644 DOI: 10.1038/nrd2359] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Insulin-like growth factor 1 (IGF1) is a polypeptide hormone that has a high degree of structural similarity to human proinsulin. Owing to its ubiquitous nature and its role in promoting cell growth, strategies to inhibit IGF1 actions are being pursued as potential adjunctive measures for treating diseases such as short stature, atherosclerosis and diabetes. In addition, most tumour cell types possess IGF1 receptors and conditions in the tumour microenvironment, such as hypoxia, can lead to enhanced responsiveness to IGF1. Therefore, inhibiting IGF1 action has been proposed as a specific mechanism for potentiating the effects of existing anticancer therapies or for directly inhibiting tumour cell growth.
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Affiliation(s)
- David R Clemmons
- Division of Endocrinology, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7170, USA.
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25
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Borer KT. Physical activity in the prevention and amelioration of osteoporosis in women : interaction of mechanical, hormonal and dietary factors. Sports Med 2005; 35:779-830. [PMID: 16138787 DOI: 10.2165/00007256-200535090-00004] [Citation(s) in RCA: 226] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Osteoporosis is a serious health problem that diminishes quality of life and levies a financial burden on those who fear and experience bone fractures. Physical activity as a way to prevent osteoporosis is based on evidence that it can regulate bone maintenance and stimulate bone formation including the accumulation of mineral, in addition to strengthening muscles, improving balance, and thus reducing the overall risk of falls and fractures. Currently, our understanding of how to use exercise effectively in the prevention of osteoporosis is incomplete. It is uncertain whether exercise will help accumulate more overall peak bone mass during childhood, adolescence and young adulthood. Also, the consistent effectiveness of exercise to increase bone mass, or at least arrest the loss of bone mass after menopause, is also in question. Within this framework, section 1 introduces mechanical characteristics of bones to assist the reader in understanding their responses to physical activity. Section 2 reviews hormonal, nutritional and mechanical factors necessary for the growth of bones in length, width and mineral content that produce peak bone mass in the course of childhood and adolescence using a large sample of healthy Caucasian girls and female adolescents for reference. Effectiveness of exercise is evaluated throughout using absolute changes in bone with the underlying assumption that useful exercise should produce changes that approximate or exceed the absolute magnitude of bone parameters in a healthy reference population. Physical activity increases growth in width and mineral content of bones in girls and adolescent females, particularly when it is initiated before puberty, carried out in volumes and at intensities seen in athletes, and accompanied by adequate caloric and calcium intakes. Similar increases are seen in young women following the termination of statural growth in response to athletic training, but not to more limited levels of physical activity characteristic of longitudinal training studies. After 9-12 months of regular exercise, young adult women often show very small benefits to bone health, possibly because of large subject attrition rates, inadequate exercise intensity, duration or frequency, or because at this stage of life accumulation of bone mass may be at its natural peak. The important influence of hormones as well as dietary and specific nutrient abundance on bone growth and health are emphasised, and premature bone loss associated with dietary restriction and estradiol withdrawal in exercise-induced amenorrhoea is described. In section 3, the same assessment is applied to the effects of physical activity in postmenopausal women. Studies of postmenopausal women are presented from the perspective of limitations of the capacity of the skeleton to adapt to mechanical stress of exercise due to altered hormonal status and inadequate intake of specific nutrients. After menopause, effectiveness of exercise to increase bone mineral depends heavily on adequate availability of dietary calcium. Relatively infrequent evidence that physical activity prevents bone loss or increases bone mineral after menopause may be a consequence of inadequate calcium availability or low intensity of exercise in training studies. Several studies with postmenopausal women show modest increases in bone mineral toward the norm seen in a healthy population in response to high-intensity training. Physical activities continue to stimulate increases in bone diameter throughout the lifespan. These exercise-stimulated increases in bone diameter diminish the risk of fractures by mechanically counteracting the thinning of bones and increases in bone porosity. Seven principles of bone adaptation to mechanical stress are reviewed in section 4 to suggest how exercise by human subjects could be made more effective. They posit that exercise should: (i) be dynamic, not static; (ii) exceed a threshold intensity; (iii) exceed a threshold strain frequency; (iv) be relatively brief but intermittent; (v) impose an unusual loading pattern on the bones; (vi) be supported by unlimited nutrient energy; and (vii) include adequate calcium and cholecalciferol (vitamin D3) availability.
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Affiliation(s)
- Katarina T Borer
- Division of Kinesiology, The University of Michigan, Ann Arbor, Michigan 48109-2214, USA.
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26
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Nilsson O, Marino R, De Luca F, Phillip M, Baron J. Endocrine regulation of the growth plate. HORMONE RESEARCH 2005; 64:157-65. [PMID: 16205094 DOI: 10.1159/000088791] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Longitudinal bone growth occurs at the growth plate by endochondral ossification. Within the growth plate, chondrocyte proliferation, hypertrophy, and cartilage matrix secretion result in chondrogenesis. The newly formed cartilage is invaded by blood vessels and bone cells that remodel the newly formed cartilage into bone tissue. This process of longitudinal bone growth is governed by a complex network of endocrine signals, including growth hormone, insulin-like growth factor I, glucocorticoid, thyroid hormone, estrogen, androgen, vitamin D, and leptin. Many of these signals regulate growth plate function, both by acting locally on growth plate chondrocytes and also indirectly by modulating other endocrine signals in the network. Some of the local effects of hormones are mediated by changes in paracrine factors that control chondrocyte proliferation and differentiation. Many human skeletal growth disorders are caused by abnormalities in the endocrine regulation of the growth plate. This review provides an overview of the endocrine signals that regulate longitudinal bone growth, their interactions, and the mechanisms by which they affect growth plate chondrogenesis.
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Affiliation(s)
- Ola Nilsson
- Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1862, USA.
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27
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Mochizuki S, Yoshida S, Yamanaka Y, Matsuo H, Maruo T. Effects of estriol on proliferative activity and expression of insulin-like growth factor-I (IGF-I) and IGF-I receptor mRNA in cultured human osteoblast-like osteosarcoma cells. Gynecol Endocrinol 2005; 20:6-12. [PMID: 15969240 DOI: 10.1080/09513590400020831] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The present study was undertaken to elucidate whether estriol (E3) affects the proliferative activity and the expression of insulin-like growth factor-I (IGF-I) mRNA and IGF-I receptor (IGF-IR) mRNA in cultured human osteoblast-like osteosarcoma cells (HOS TE85). In this study, the effects of E3 on cultured HOS TE85 cells were compared with those of 17 beta-estradiol (E2). HOS TE85 cells were subcultured in phenol red-free Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum for 72 h and then stepped down to serum-free conditions for an additional 72 h in the absence or presence of E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l). Treatment with either E3 (3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in an increase in the number of cultured HOS TE85 cells and their uptake of bromodeoxyuridine. Northern blot hybridization with a IGF-I cDNA probe revealed that RNA prepared from cultured HOS TE85 cells contained IGF-I mRNA transcripts of 1.8, 4.4 and 7.5 kb. Treatment with either E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in increased expression of the three mRNA transcripts relative tot hose in untreated control cultures. Semi-quantitative, reverse transcription polymerase chain reaction analysis showed that the 440-bp IGF-IR mRNA transcript was present in HOS TE85 cells and that treatment with either E3 or E2 did not affect the IGF-IRmRNA expression in these cells. These results demonstrate that E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) exerts profound effects on the proliferative potential of cultured HOS TE85 cells, compatible with that of E2 (3.67 x 10(-8) mol/l), through the induction of IGF-I mRNA expression without affecting IGF-IR mRNA expression in these cells.
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Affiliation(s)
- Shinsuke Mochizuki
- Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan
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28
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Kirpensteijn J, Timmermans-Sprang EPM, van Garderen E, Rutteman GR, Lantinga-van Leeuwen IS, Mol JA. Growth hormone gene expression in canine normal growth plates and spontaneous osteosarcoma. Mol Cell Endocrinol 2002; 197:179-85. [PMID: 12431811 DOI: 10.1016/s0303-7207(02)00269-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The indirect growth-promoting action of pituitary-derived growth hormone (GH) on skeletal growth is thought to be mediated by systemically released insulin-like growth factor-I (IGF-I) and by locally produced IGF-I. The aim of the present study was to document whether GH is expressed locally in canine bone and spontaneous osteosarcoma. Using RT-PCR the expression of GH mRNA was demonstrated in the metaphyseal, but not in the majority of epiphyseal ends of the canine growth plate. GH mRNA was also present in 25% of the canine osteosarcoma specimens. The expression of GH mRNA in predominantly active osteoid forming areas was associated with the presence of immunoreactive GH in osteoblasts, as shown by immunohistochemistry. It is concluded that locally produced GH is involved in osteoid formation and may play a role in the growth of neoplastic bone lesions in the dog.
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Affiliation(s)
- Jolle Kirpensteijn
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, P.O. Box 80.154, NL-3508 TD Utrecht, The Netherlands.
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Visnapuu V, Peltomäki T, Rönning O, Syrjänen S. Distribution of insulin-like growth factor-I mRNA in the mandibular condyle and rib cartilage of the rat during growth. Arch Oral Biol 2002; 47:791-8. [PMID: 12446186 DOI: 10.1016/s0003-9969(02)00115-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study makes a molecular biological comparison of primary and secondary cartilage at an early phase of postnatal development. The distribution of insulin-like growth factor-I (IGF-I) mRNA expression in the mandibular condyle and rib cartilage of 1-28-day-old rats was examined after in situ hybridisation using an oligo probe cocktail for IGF-I mRNA. In the condyle, expression was localised to a narrow strip under the articular layer where the cells are undifferentiated. Essentially, no differences were found in IGF-I synthesis within three samples from the same age group or between different age groups. In rib cartilage, IGF-I mRNA was localised within the germinative, proliferative and early hypertrophic cell layers in 1-28-day-old rats. Again, there were no differences in expression among animals of the same age or as a function of age. This pattern of IGF-I mRNA expression indicates that IGF-I synthesis during growth of the mandibular condylar cartilage is different from that of costal cartilage. The findings shed light on the problem of overgrowth often associated with the use of costochondral grafts to replace defective mandibular condyles.
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Affiliation(s)
- V Visnapuu
- Institute of Dentistry, University of Turku, Lemminkäisenkatu 2, FIN-20520, Turku, Finland.
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30
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Jaffe CA, Turgeon DK, Lown K, Demott-Friberg R, Watkins PB. Growth hormone secretion pattern is an independent regulator of growth hormone actions in humans. Am J Physiol Endocrinol Metab 2002; 283:E1008-15. [PMID: 12376329 DOI: 10.1152/ajpendo.00513.2001] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The importance of gender-specific growth hormone (GH) secretion pattern in the regulation of growth and metabolism has been demonstrated clearly in rodents. We recently showed that GH secretion in humans is also sexually dimorphic. Whether GH secretion pattern regulates the metabolic effects of GH in humans is largely unknown. To address this question, we administered the same daily intravenous dose of GH (0.5 mg. m(-2). day(-1)) for 8 days in different patterns to nine GH-deficient adults. Each subject was studied on four occasions: protocol 1 (no treatment), protocol 2 (80% daily dose at 0100 and 10% daily dose at 0900 and 1700), protocol 3 (8 equal boluses every 3 h), and protocol 4 (continuous GH infusion). The effects of GH pattern on serum IGF-I, IGF-binding protein (IGFBP)-3, osteocalcin, and urine deoxypyridinoline were measured. Hepatic CYP1A2 and CYP3A4 activities were assessed by the caffeine and erythromycin breath tests, respectively. Protocols 3 and 4 were the most effective in increasing serum IGF-I and IGFBP-3, whereas protocols administering pulsatile GH had the greatest effects on markers of bone formation and resorption. All GH treatments decreased CYP1A2 activity, and the effect was greatest for pulsatile GH. Pulsatile GH decreased, whereas continuous GH infusion increased, CYP3A4 activity. These data demonstrate that GH pulse pattern is an independent parameter of GH action in humans. Gender differences in drug metabolism and, potentially, gender differences in growth rate may be explained by sex-specific GH secretion patterns.
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Affiliation(s)
- Craig A Jaffe
- Divisions of Endocrinology and Metabolism, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA.
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31
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N'Diaye MR, Sun SS, Fanua SP, Loseth KJ, Shaw Wilgis EF, Crabo BG. Growth hormone receptors in the porcine testis during prepuberty. Reprod Domest Anim 2002; 37:305-9. [PMID: 12354185 DOI: 10.1046/j.1439-0531.2002.00364.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Supplementation of exogenous growth hormone (GH) during prepuberty advances onset of spermatogenesis in boars, but the mechanism of action is unknown. The present study is an investigation of the presence and characteristics of testicular growth hormone receptors (GHR). A total of 36 boars were castrated, three boars every 10 days, between the ages of 10 and 120 days. Testicular membrane preparations of 10, 20, 30, 50, 70, 100 and 120-day-old boars were used to determine (125)I-bGH binding and Scatchard analysis. Liver from a 60-kg barrow was used for comparison. Specific (125)I-bGH binding to testicular membrane preparations occurred in all age groups with the exception of 20-day-old boars at levels of 30-40% of liver binding. At 30 days of age the unlabelled bGH at 1.1 ng/tube achieved half maximal inhibition (ID(50)). Results of Scatchard analysis indicated a single class of binding sites. Binding affinity was 2.89 x 10(9) m with a binding capacity of 12 fmole/mg membrane protein. The results from this study suggest that GH may act directly on the cells of the prepubertal boar testis.
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Affiliation(s)
- M R N'Diaye
- Department of Animal Science, Division of Veterinary Theriogenology, College of Veterinary Medicine, University of Minnesota, St Paul, MN, USA
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32
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Zapf J, Gosteli-Peter M, Weckbecker G, Hunziker EB, Reinecke M. The somatostatin analog octreotide inhibits GH-stimulated, but not IGF-I-stimulated, bone growth in hypophysectomized rats. Endocrinology 2002; 143:2944-52. [PMID: 12130560 DOI: 10.1210/endo.143.8.8970] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IGF-I mediates growth-promoting actions of GH. In the present study we investigated whether the somatostatin analog octreotide blunts the stimulatory effects of GH and/or IGF-I on bone growth in hypophysectomized rats infused for 6 d with vehicle, GH, or IGF-I. We found that octreotide significantly suppressed the GH-induced rise in liver IGF-I mRNA (-27%) and peptide (-32%) and the serum IGF-I level (-26%) and concomitantly inhibited GH-stimulated, but not IGF-I-stimulated, body weight gain (-31%), tibial epiphyseal width (-14%), and bone growth rate (-24%). Furthermore, octreotide significantly reduced the GH-induced increase in the number of IGF-I immunoreactive chondrocytes in all layers (except in the upper hypertrophic zone) of the tibial growth plate cartilage (P < 0.0001 for stem cell and proliferative zone; P < 0.0005 for lower hypertrophic zone). These findings demonstrate that octreotide does not interfere with IGF-I action, but does interfere with local GH-stimulated IGF-I production in the growth plate. Thus, besides inhibiting pituitary GH secretion, octreotide exerts inhibitory peripheral effects on GH-stimulated longitudinal bone growth.
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Affiliation(s)
- Jürgen Zapf
- Division of Endocrinology and Diabetes, Department of Internal Medicine, University Hospital, 8091 Zurich, Switzerland.
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Clemmons DR, Busby WH, Garmong A, Schultz DR, Howell DS, Altman RD, Karr R. Inhibition of insulin-like growth factor binding protein 5 proteolysis in articular cartilage and joint fluid results in enhanced concentrations of insulin-like growth factor 1 and is associated with improved osteoarthritis. ARTHRITIS AND RHEUMATISM 2002; 46:694-703. [PMID: 11920405 DOI: 10.1002/art.10222] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The complement component C1s is present in dog joint fluid in an activated state. Since C1s degrades insulin-like growth factor binding protein 5 (IGFBP-5), we undertook to determine whether inhibiting C1s in joint fluid would result in an increase in the amount of intact IGFBP-5 and IGF-1 in cartilage and joint fluid, and whether C1s inhibition would be associated with a reduction in cartilage destruction during the development of osteoarthritis (OA). METHODS Twenty-two dogs were randomized to 3 treatment groups. All dogs underwent anterior cruciate ligament transection and were exercised. Dogs received 1 of 3 treatments: buffer alone (controls; n = 6); PB-145, a peptide derived from the sequence of antithrombin III (n = 9); and pentosan polysulfate (PPS; n = 7). PB-145 or saline was injected into the joint space 3 times per week for 3 weeks. PPS was injected intramuscularly weekly for 3 weeks. RESULTS Joint histology showed preservation of chondrocytes and a smooth joint surface in the animals treated with PB-145 and PPS. Mankin scoring showed statistically significant reductions in joint destruction with PB-145 and PPS treatments (P < 0.01) compared with buffer control. Mean active collagenase concentrations were decreased by these two treatments. Immunoblotting of joint fluid showed that both treatments increased concentrations of intact IGFBP-5. Direct analysis of IGFBP-3 and IGFBP-5 protease activity showed that IGFBP-5 was degraded more rapidly and that PB-145 and PPS inhibited the degradation of both proteins. Total IGF-1 concentrations in joint fluid were increased 5.6-5.8-fold by these two treatments. Analysis showed that C1s was being activated in joint fluid and that its activation was inhibited by the addition of PB-145 or PPS. CONCLUSION The findings suggest that direct inhibition of the serine protease C1s results in increased concentrations of intact IGFBP-5 and that proteolysis of IGFBP-3 is also inhibited, probably by the inhibition of some other protease. This increase in concentrations of intact IGFBP-3 and IGFBP-5 leads to an increase in IGF-1 which is associated with an improvement in joint architecture during the development of OA.
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Affiliation(s)
- David R Clemmons
- Division of Endocrinology, University of North Carolina, Chapel Hill, 27599-7170, USA.
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Bowers D, McKenzie D, Dutta D, Wheeless CR, Cohen WR. Growth hormone treatment after cesarean delivery in rats increases the strength of the uterine scar. Am J Obstet Gynecol 2001; 185:614-7. [PMID: 11568787 DOI: 10.1067/mob.2001.117185] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We sought to determine whether postcesarean treatment of rats with growth hormone (GH) affected the strength of the uterine incision in the puerperium and in a subsequent pregnancy. STUDY DESIGN Forty-eight near-term pregnant rats were delivered by cesarean section. Half received subcutaneous recombinant human GH (2.0 mg x kg(-1) x d(-1)) for 7 days; control animals received saline injections. Four weeks after delivery, the uterine bursting pressure was determined in 5 treated and 5 control animals. Eight rats in each group were used to study uterine hydroxyproline concentrations and the histologic characteristics of the scar. Twenty-two animals were rebred 30 to 40 days after their cesarean sections. After repeat cesarean delivery, on day 19, the bursting pressure and hydroxyproline concentrations of the previous hysterotomy scar were determined. RESULTS The uterine horn bursting pressure in the GH-treated animals was significantly greater than that in the control animals both 28 days postpartum and near term in a subsequent pregnancy. The uterine hydroxyproline concentrations followed the same pattern. Histologic study of the scars showed they were thicker and had less cellularity in the treated animals than in the control animals. CONCLUSION Postcesarean treatment with GH increased the bursting strength of rat uterine incisions. This effect was accompanied by a significant increase in collagen content and persisted through a subsequent pregnancy.
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Affiliation(s)
- D Bowers
- Department of Obstetrics and Gynecology, and the Institute for Special Pelvic Surgery, Sinai Hospital of Baltimore, MD, USA
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Butler AA, Le Roith D. Control of growth by the somatropic axis: growth hormone and the insulin-like growth factors have related and independent roles. Annu Rev Physiol 2001; 63:141-64. [PMID: 11181952 DOI: 10.1146/annurev.physiol.63.1.141] [Citation(s) in RCA: 235] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The traditionally accepted theory has been that most of the biological effects of growth hormone (GH) are mediated by circulating (endocrine) insulin-like growth factor-I (IGF-I). This dogma was modified when it was discovered that most tissues express IGF-I that can act via an autocrine/paracrine fashion. In addition, both GH and IGF-I had independent effects on various target tissues. Using tissue-specific gene deletion of IGF-I in the liver, it has been shown that circulating IGF-I is predominantly liver-derived but is not essential for normal postnatal growth. Therefore, it is proposed that non-hepatic tissue-derived IGF-I may be sufficient for growth and development. Thus the original somatomedin hypothesis has undergone further modifications.
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Affiliation(s)
- A A Butler
- The Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland Oregon 97201-3098, USA.
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Abstract
Postnatal growth and development are coordinated by genetic and environmental influences and numerous growth factors. The growth hormone-insulin-like growth factor-I (GH-IGF-I) axis plays an essential role in these processes. Although the GH-IGF-I axis is a closely coordinated system, both GH and IGF-I have independent actions, many of which have become apparent more recently following the characterization of clinical syndromes and the development of mouse models. Genetic manipulation of mice has enabled investigators to re-examine many of the established hypotheses regarding the GH-IGF-I axis. Results gleaned from a mouse model created by tissue-specific gene deletion of liver IGF-I has enabled investigators to re-evaluate the original 'somatomedin hypothesis'.
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Affiliation(s)
- D Le Roith
- Clinical Endocrinology Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1758, USA.
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Takahashi K, Yamane A, Bringas P, Caton J, Slavkin HC, Zeichner-David M. Induction of amelogenin and ameloblastin by insulin and insulin-like growth factors (IGF-I and IGF-II) during embryonic mouse tooth development in vitro. Connect Tissue Res 2001; 38:269-78; discussion 295-303. [PMID: 11063034 DOI: 10.3109/03008209809017047] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Insulin and insulin-like growth factors (IGF-I and IGF-II) are considered pleiotropic, acting as both mitogen and differentiation factors. Several investigators have demonstrated the expression of insulin, IGFs, their cognate receptors and IGF binding proteins during tooth morphogenesis. Previous work done in our laboratory indicated that exogenous insulin and IGFs induce the accumulation of enamel extracellular matrix on mouse mandibular molars cultured in a serumless, chemically defined medium. In order to determine the level of control of these factors in the induction of enamel biomineralization, we designed experiments to quantitate mRNAs for enamel specific-gene products. Mandibular first molars (MI) obtained from E15 Swiss Webster mice were placed in organ culture in the presence of insulin (1,000 ng/ml), IGF-I (100 ng/ml) or IGF-II (100 ng/ml) for 6, 12 and 18-days. At termination date, the RNA was extracted and the concentration of mRNAs for amelogenin, tuftelin and ameloblastin were determined using a quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) technique (PCR mimic). Our results showed that after 6-days in culture; treatment with insulin, IGF-I and IGF-II increased the synthesis of amelogenin and ameloblastin. In contrast, the expression of tuftelin mRNA was not affected by either factor. In conclusion, our studies showed that the increase in enamel matrix formation by overexpression of IGFs is the result of transcriptional regulation of enamel specific proteins like amelogenin and ameloblastin but not tuftelin. These studies also suggest that the regulatory mechanisms controlling tuftelin gene expression are different than the mechanisms regulating ameloblastin and amelogenin transcription.
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Affiliation(s)
- K Takahashi
- Craniofacial Development Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Since the original somatomedin hypothesis was conceived, a number of important discoveries have allowed investigators to modify the concept. Originally somatic growth was thought to be controlled by pituitary GH and mediated by circulating insulin-like growth factor-I (IGF-I, somatomedin C) expressed exclusively by the liver. With the discovery that IGF-I is produced by most, if not all, tissues, the role of autocrine/paracrine IGF-I vs. the circulating form has been hotly debated. Recent experiments using transgenic and gene-deletion technologies have attempted to answer these questions. In the liverspecific igf-1 gene-deleted mouse model, postnatal growth and development are normal despite the marked reduction in circulating IGF-I and IGF-binding protein levels; free IGF-I levels are normal. Thus, the normal postnatal growth and development in these animals may be due to normal free IGF-I levels (from as yet unidentified sources), although the role of autocrine/paracrine IGF-I has yet to be determined.
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Affiliation(s)
- D Le Roith
- Clinical Endocrinology Branch, National Institutes of Health, Bethesda, Maryland 20892-1758, USA.
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Saunders MC, Gemmell RT, Curlewis JD. Insulin-like growth factor 2 cDNA cloning and ontogeny of gene expression in the liver of the marsupial brushtail possum (Trichosurus vulpecula). Gen Comp Endocrinol 2001; 121:114-24. [PMID: 11161776 DOI: 10.1006/gcen.2000.7581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cDNA sequence for insulin-like growth factor 2 (IGF-2) was determined from the liver of the marsupial brushtail possum (Trichosurus vulpecula) using reverse transcription followed by polymerase chain reaction (RT-PCR) with gene-specific primers. The 359 bp of possum sequence encompassed the mature peptide, 27 bp of the signal peptide, and 125 bp of the E-peptide. Alignment of the deduced amino acid sequence with those from other species indicated that the mature peptide was 71 amino acids in length, 4 amino acids longer than most other mammals. At both the nucleotide and amino acid levels there was a high degree of sequence identity with IGF-2 from other mammalian and nonmammalian species. Amino acid identity ranged from 94.4% with a variant form of human IGF-2 to 80.3% with zebrafinch IGF-2. Northern analysis revealed that radiolabeled possum IGF-2 cDNA hybridized to multiple transcripts in the liver of both adult possums and 150-day-old pouch young and that the overall level of expression was greater in pouch young. Semiquantitative RT-PCR with total RNA from liver samples of pouch young aged 12 to 150 days postpartum and adults confirmed that IGF-2 gene expression was two to three times more abundant in pouch young than in adults but there was no significant change in the level of expression during pouch life. Unlike other mammalian species, in which there is a decline in levels of liver IGF-2 gene expression around the time of birth, levels in the marsupial brushtail possum remain elevated for at least 150 days after birth. This suggests that the decline in liver IGF-2 expression in marsupials and eutherians occurs at a similar stage of development and may reflect a role for this growth factor during the postnatal growth and development of the marsupial.
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Affiliation(s)
- M C Saunders
- Department of Physiology and Pharmacology, The University of Queensland, Brisbane, 4072, Australia
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Abstract
Recent case-controlled studies have found increases in the serum levels of insulin-like growth factor-I (IGF-I) in subjects who had, or who eventually developed, prostate or premenopausal breast cancers. Since growth hormone (GH) increases IGF-I levels, concern has been raised regarding its potential role as a cancer initiation factor. The epidemiological studies, which indicate an association between serum IGF-I levels and cancer risk, have not established causality. In fact, several alternative explanations for the elevated serum IGF-I levels in cancer patients may be proposed based on human and animal models. First, an effect of IGF-I causing symptomatic benign tissue hyperplasia may result in an ascertainment bias leading to an initiation of procedures resulting in the diagnosis of asymptomatic cancers. Second, elevated serum IGF-I in cancer patients may originate within the tumor (as suggested by some animal studies). Thirdly, serum IGF-I may actually be a surrogate marker of tissue IGF-I levels or of nutritional factors, which are not under GH control and may be involved in cancer initiation. The role of GH in cancer initiation is further negated by the fact that in acromegaly, the incidence of cancer, other than possibly colonic neoplasia does not appear to be significantly increased. Furthermore, GH transgenic mice, with high IGF-I levels, do not develop breast, prostate, or colonic malignancies. It is known that IGFBP-3 can inhibit IGF action on cancer cells in vitro and also can induce apoptosis via an IGF-independent mechanism. Importantly, in addition to increasing IGF-I levels, GH also increases the serum levels of IGFBP-3 and serum IGFBP-3 levels have been shown to be negatively correlated with the risk of cancer in the above mentioned epidemiological studies and in a similar study on colon cancer. These studies suggest that cancer risk is increased in individuals in whom both high IGF-I levels and low IGFBP-3 levels are present. In subjects treated with GH, IGF-I and IGFBP-3 levels both rise together and are not within the elevated cancer-risk range, based on published studies. Long-term studies are needed to assess the potential risks, including the long-term cancer risk associated with GH therapy. These should take into account several factors, including the duration of exposure, the risk magnitude associated with the degree of serum IGF-I elevation, and the adjusted risk based on a concomitant increase in IGFBP-3 levels. Since GH treated patients often have sub-normal IGF-I serum levels, which normalize on therapy, one might predict that their cancer risk on GH therapy should not increase above the normal population. Until further research in the area dictates otherwise, on-going cancer surveillance and routine monitoring of serum IGF-I and IGFBP-3 levels in GH-recipients should be the standard of care. At present, the data that are available do not warrant a change in our current management of approved indications for GH therapy.
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Affiliation(s)
- P Cohen
- Department of Pediatrics, Mattel Children's Hospital, UCLA, Los Angeles, CA 90095-1752, USA.
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Sims NA, Clément-Lacroix P, Da Ponte F, Bouali Y, Binart N, Moriggl R, Goffin V, Coschigano K, Gaillard-Kelly M, Kopchick J, Baron R, Kelly PA. Bone homeostasis in growth hormone receptor-null mice is restored by IGF-I but independent of Stat5. J Clin Invest 2000; 106:1095-103. [PMID: 11067862 PMCID: PMC301420 DOI: 10.1172/jci10753] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Growth hormone (GH) regulates both bone growth and remodeling, but it is unclear whether these actions are mediated directly by the GH receptor (GHR) and/or IGF-I signaling. The actions of GH are transduced by the Jak/Stat signaling pathway via Stat5, which is thought to regulate IGF-I expression. To determine the respective roles of GHR and IGF-I in bone growth and remodeling, we examined bones of wild-type, GHR knockout (GHR(-/-)), Stat5ab(-/-), and GHR(-/-) mice treated with IGF-I. Reduced bone growth in GHR(-/-) mice, due to a premature reduction in chondrocyte proliferation and cortical bone growth, was detected after 2 weeks of age. Additionally, although trabecular bone volume was unchanged, bone turnover was significantly reduced in GHR(-/-) mice, indicating GH involvement in the high bone-turnover level during growth. IGF-I treatment almost completely rescued all effects of the GHR(-/-) on both bone growth and remodeling, supporting a direct effect of IGF-I on both osteoblasts and chondrocytes. Whereas bone length was reduced in Stat5ab(-/-) mice, there was no reduction in trabecular bone remodeling or growth-plate width as observed in GHR(-/-) mice, indicating that the effects of GH in bone may not involve Stat5 activation.
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Affiliation(s)
- N A Sims
- Institut Nationale de la Santé et de la Recherche Médicale (INSERM), Unité 344, Endocrinologie Moléculaire, Faculté de Médecine Necker, Paris, France
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Herrington J, Smit LS, Schwartz J, Carter-Su C. The role of STAT proteins in growth hormone signaling. Oncogene 2000; 19:2585-97. [PMID: 10851057 DOI: 10.1038/sj.onc.1203526] [Citation(s) in RCA: 196] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Growth hormone (GH) has long been known to be the body's primary regulator of body growth and a regulator of metabolism, yet the mechanisms by which GH regulates the transcription of specific genes required for these processes are just now being delineated. GH binding to its receptor recruits and activates the receptor-associated JAK2 that in turn phosphorylates tyrosines within itself and the GH receptor. These tyrosines form binding sites for a number of signaling proteins, including members of the family of signal transducers and activators of transcription (STAT). Among the known signaling molecules for GH, STAT proteins play a particularly prominent role in the regulation of gene transcription. This paper will review what is currently understood about which STAT proteins are regulated by GH, how they are regulated by GH, the GH-dependent genes they regulate, and discuss current theories about how GH-activated STAT signaling is regulated. Particular attention will be given to the novel role that STAT5 plays in sexually dimorphic gene expression in the liver as determined by the secretory pattern of GH and the role of STAT5 in body growth. Oncogene (2000).
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Affiliation(s)
- J Herrington
- Department of Physiology, University of Michigan Medical School, Ann Arbor, Michigan, MI 48109-0622, USA
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Elhassan AM, Adem A, Suliman IA, Mustafa A, Lindgren JU. Prolactin, growth hormone, and IGF-1 in ankles and plasma of adjuvant arthritic rats. Scand J Rheumatol 2000; 28:368-73. [PMID: 10665743 DOI: 10.1080/03009749950155364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In this study we have investigated the levels of prolactin, growth hormone, and insulin-like growth factor-1 in plasma and in tissue extracts of ankle joints of rats with acute or chronic adjuvant arthritis using enzyme immunoassay (EIA) and radioimmunoassay (RIA). We found a stable content of prolactin in plasma of the different groups but a significantly increased concentration of growth hormone was observed in the plasma of the group with chronic arthritis. Moreover, an increased concentration of insulin-like growth factor-1 was noted in the plasma of the acute group. This evidently had returned to normal levels in the chronic group. In contrast, decreased concentrations of prolactin, growth hormone, and insulin-like growth factor-1 were found in tissue extracts of ankle joints of the group with chronic arthritis. The changes in the levels of these hormones in adjuvant arthritis might suggest that they play a role in the pathogenesis of the disease. Understanding the mechanism(s) of hormonal participation in adjuvant arthritis may open new treatment strategies for rheumatoid arthritis and other inflammatory disorders.
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Affiliation(s)
- A M Elhassan
- Department of Orthopaedic Surgery, Karolinska Institute, Sweden
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Symons AL, Seymour GJ. A histological study of the effect of growth hormone on odontogenesis in the Lewis dwarf rat. Arch Oral Biol 2000; 45:123-31. [PMID: 10716616 DOI: 10.1016/s0003-9969(99)00123-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The effect of growth hormone (GH) on the dentition has been described in children with pituitary dwarfism where teeth fail to form; those that do form tend to be reduced in size and the eruption potential is diminished. The aim here was to examine the effect of GH on odontogenesis via molar development in Lewis (control), dwarf (Dw) and Dw GH-treated (Dw+GH) rats aged 3, 6, 9, 12 and 15 days. Dw+GH animals received a twice-daily dose (65 microg/kg) of GH which commenced at 2 days of age. Animals were killed, mandibles removed, processed to embedding in paraffin, sectioned and stained for histological examination of molar morphology during development. Variations in enamel mineralization and root development were observed. In 6-day-old animals, enamel mineralization was delayed in Dw and Dw+GH animals. Root initiation was evident at 6 days of age in controls but was not observed until 9 days of age in Dw and Dw+GH animals. At 12 days of age, maturation of enamel in Dw and Dw+GH animals remained delayed. By 15 days of age no variation in tooth development was evident. These data indicate that enamel mineralization is affected by the level of circulating GH in the rat. A specific deficiency of GH did not appear to delay bone resorption prior to tooth emergence.
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Affiliation(s)
- A L Symons
- School of Dentistry, The University of Queensland, Brisbane, Australia.
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Ohlsson C, Lindahl A, Isgaard J, Nilsson A, Isaksson OGP. The Dual Effector Theory. Compr Physiol 1999. [DOI: 10.1002/cphy.cp070516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Scaramuzzi RJ, Murray JF, Downing JA, Campbell BK. The effects of exogenous growth hormone on follicular steroid secretion and ovulation rate in sheep. Domest Anim Endocrinol 1999; 17:269-77. [PMID: 10527129 DOI: 10.1016/s0739-7240(99)00043-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Growth hormone (GH) has diverse actions in many tissues, including the follicle. This paper summarizes three experiments that examined the effects of GH and insulin-like growth factor (IGF)-I on the ovary. Ewes given oGH and pregnant mane serum gonadotrophin were compared with control and pregnant mane serum gonadotrophin-treated ewes. Ewes, with synchronized cycles, were given varying doses of pregnant mane serum gonadotrophin and/or oGH to determine if oGH is able to augment ovulation rate (Experiment 1). Experiments 2 and 3 used the ovarian autotransplant model. Ewes were infused via the ovarian artery with oGH (Experiment 2) or insulin-like growth factor I (IGF-I) (Experiment 3). Both were administered for 12 hr on Day 10. In Experiment 2, ewes were given intravenous gonadotropin releasing hormone (150 ng i.v.) at -2.5 and 10.5 hr relative to infusion. Ovarian and jugular venous blood was collected every 15 min from -30 to 150 min relative to gonadotropin releasing hormone. In Experiment 3, luteolysis was induced at the end of infusion. Ovarian and jugular venous blood was collected every 3 hr from before and until 84 hr after the infusion. Estradiol and androstenedione were assayed in ovarian venous plasma and GH in jugular venous plasma. In Experiment 1, treatment with oGH increased the jugular venous concentration of GH. However, in Experiment 2 treatment with oGH via the ovarian artery did not increase jugular venous GH but did increase ovarian venous GH. Treatment with oGH had no effect on ovulation rate (Experiment 1) or the secretion of androstenedione and estradiol (Experiment 2). Infusion of IGF-I (Experiment 3) increased the secretion of estradiol during the follicular phase. These data show that short-term treatment of sheep with GH had no in vivo effects on the follicle and that IGF-I was a potent stimulator of follicular steroidogenesis in vivo.
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Affiliation(s)
- R J Scaramuzzi
- Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK.
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Abstract
Several lines of evidence suggest that the insulinlike growth factors play a role in fracture healing. They promote cell proliferation and matrix synthesis by chondrocytes and osteoblasts, the two cell types largely responsible for the formation of fracture callus. Circulating levels of insulinlike growth factor I and bone mineral density decrease with increasing age, and administration of insulinlike growth factor I increases bone turnover in patients with low bone mineral density. Insulinlike growth factor I may accelerate the normal healing of intramembranous bone defects, inducing the healing of defects that otherwise would not heal. An important role of insulinlike growth factor I is to mediate many of the actions of growth hormone on the skeleton. Considerable effort has been devoted to testing the effect of growth hormone and, thereby, indirectly that of insulinlike growth factor I on fracture healing. These studies have yielded such disparate results that no general conclusions regarding the effect of growth hormone (or of growth hormone dependent insulinlike growth factor I) on fracture healing currently can be drawn. Additional studies are needed to clarify the role of the insulinlike growth factors in the fracture healing process and to determine how their anabolic actions can be enlisted in the clinical enhancement of fracture healing.
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Affiliation(s)
- S B Trippel
- Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA
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Jux C, Leiber K, Hügel U, Blum W, Ohlsson C, Klaus G, Mehls O. Dexamethasone impairs growth hormone (GH)-stimulated growth by suppression of local insulin-like growth factor (IGF)-I production and expression of GH- and IGF-I-receptor in cultured rat chondrocytes. Endocrinology 1998; 139:3296-305. [PMID: 9645706 DOI: 10.1210/endo.139.7.6099] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Growth depression as a side effect of glucocorticoid therapy in childhood is partially mediated by alterations of the somatotropic hormone axis. The mechanisms of interaction between glucocorticoids and somatotropic hormones on the cellular and molecular level are poorly understood. In an experimental model of primary cultured rat growth plate chondrocytes, basal as well as GH (40 ng/ml) or insulin-like growth factor (IGF)-I (60 ng/ml)-stimulated growth was suppressed dose dependently (10(-l2)-10(-7)M) by dexamethasone (Dexa). An IGF-I antibody specifically and dose dependently inhibited the GH- but not the basic fibroblast growth factor (bFGF)-stimulated cell proliferation. GH increased the IGF-I concentration in conditioned serum-free culture medium; this was reversed by concomitant Dexa. Dexa time dependently suppressed the transcription of GH receptor (GHR) messenger RNA (mRNA) and down-regulated the basal and GH-stimulated expression of GHR. Whereas no suppressive effect on basal type I IGF-receptor (IGFR) was observed, Dexa blocked the IGF-I induced increase of IGF binding. These results were confirmed by GHR and IGFR immunostaining. We conclude that Dexa impairs the GH-induced stimulation of local secretion and paracrine action of IGF-I and reduces the homologous increase of IGFR and GHR expression. The above experiments give further insight on the interaction between GH and glucocorticoids on the cellular and molecular level of growth plate chondrocytes.
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Affiliation(s)
- C Jux
- Department of Pediatrics, University Children's Hospitals, Heidelberg, Germany
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Carlsson L, Nilsson I, Oscarsson J. Hormonal regulation of liver fatty acid-binding protein in vivo and in vitro: effects of growth hormone and insulin. Endocrinology 1998; 139:2699-709. [PMID: 9607775 DOI: 10.1210/endo.139.6.6041] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Liver fatty acid-binding protein (LFABP) is an abundant protein in hepatocytes that binds most of the long chain fatty acids present in the cytosol. It is suggested to be of importance for fatty acid uptake and utilization in the hepatocyte. In the present study, the effects of bovine GH (bGH) and other hormones on the expression of LFABP and its messenger RNA (mRNA) were studied in hypophysectomized rats and in vitro using primary cultures of rat hepatocytes. One injection of bGH increased LFABP mRNA levels about 5-fold after 6 h, but there was no effect of this treatment on LFABP levels. However, 7 days of bGH treatment increased both LFABP mRNA and LFABP protein levels 2- to 5-fold. Female rats had higher levels of LFABP than male rats. Hypophysectomy of female rats, but not that of male rats, decreased LFABP levels markedly. Treatment of hypophysectomized rats with bGH for 7 days as two daily injections or as a continuous infusion increased LFABP levels to a similar degree. This finding indicates that the sex difference in the expression of LFABP is not regulated by the sexually dimorphic secretory pattern of GH. Neither insulin nor insulin-like growth factor I treatment of hypophysectomized rats for 6-7 days had any effect on LFABP mRNA or LFABP levels. In vitro, bGH dose-dependently increased the expression of LFABP mRNA, but only in the presence of insulin. Insulin alone had a marked dose-dependent effect on LFABP mRNA levels and was of importance for maintaining the expression of LFABP mRNA during the culture. Incubation with bGH increased LFABP mRNA levels within 3 h. GH had no effect on LFABP mRNA levels in the presence of actinomycin D, indicating a transcriptional effect of GH. Incubation with glucagon in vitro decreased LFABP mRNA levels markedly, indicating that glucagon, in contrast to GH, has an effect opposite that of insulin on LFABP mRNA expression. It is concluded that GH is an important regulator of LFABP in vivo and in vitro. In contrast to the effect of GH on insulin-like growth factor I mRNA, the presence of insulin was a prerequisite for the effect of GH on LFABP mRNA expression in vitro. The results emphasize the role of GH in the regulation of hepatic fatty acid metabolism.
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Affiliation(s)
- L Carlsson
- Department of Physiology, Göteborg University, Sweden
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