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Garg B, Arbabi A, Kirkland PA. Extrahepatic Manifestations of Chronic Hepatitis C Virus (HCV) Infection. Cureus 2024; 16:e57343. [PMID: 38562366 PMCID: PMC10982611 DOI: 10.7759/cureus.57343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2024] [Indexed: 04/04/2024] Open
Abstract
Hepatitis C virus (HCV) is a well-recognized, major cause of various liver-related conditions such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Apart from liver disease, chronic HCV infection is also associated with several extrahepatic manifestations that can lead to significant morbidity and mortality. These extrahepatic manifestations include essential mixed cryoglobulinemia (EMC), lymphomas, porphyria cutanea tarda, lichen planus, necrolytic acral erythema, glomerulonephritis, subclinical autoantibody formation, immune thrombocytopenia, thyroid disease, Sjögren's disease/sicca symptoms, diabetes mellitus, ocular diseases, musculoskeletal disorders, cardiovascular diseases, neurocognitive dysfunction, and leukocytoclastic vasculitis. We are presenting a case of chronic HCV infection linked to the extrahepatic manifestations of the disease which can be directly related to HCV or indirectly related to EMC from HCV. An awareness and knowledge of these extrahepatic manifestations will highlight the importance of recognizing the symptoms for an early diagnosis and effective anti-viral treatment in order to improve or resolve the long-term complications of chronic HCV infection.
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Affiliation(s)
- Bella Garg
- Internal Medicine/Rheumatology, Centinela Hospital, Los Angeles, USA
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2
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Arcidiacono GP, Poci C, Sella S, Torres MO, Zanchetta F, Cecchinato A, Diogo M, Peleg Falb M, Giannini S. Hepatitis C-associated Osteosclerosis (HCAO): Long-Term Follow-Up of a New Case Recovered After Antiviral Treatment. Calcif Tissue Int 2023; 113:571-577. [PMID: 37718324 DOI: 10.1007/s00223-023-01135-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
Hepatitis C-associated osteosclerosis (HCAO) is a very rare condition that can be observed in a small number of patients with Hepatitis C Virus (HCV) infection. HCAO is usually characterized by widespread bone sclerosis, associated with severe bone pain, and increased levels of bone turnover markers, especially alkaline phosphatase (ALP). In this report, we present the case of a 55-year-old woman who was affected by HCV and came to our attention for severe and diffuse bone pain. Radiological studies showed bone sclerosis, and bone mineral density (BMD) was markedly increased, as well as serum ALP levels. The patient was initially treated with intravenous pamidronate, which provided only a transient benefit on clinical symptoms. Then antiviral therapy for HCV (interferon-alfa and ribavirin) was started and it was effective in making the viral load undetectable. After a long follow-up period, we observed a persistent remission of bone pain, a reduction in BMD together with a progressive trend toward the normalization of bone turnover markers. In conclusion, HCAO, although rare, should be considered among the potential causes of increased bone mass in patients with HCV infection, and treatment for the underlying infection may be effective in controlling the manifestations of this disease.
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Affiliation(s)
| | - Carlo Poci
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Stefania Sella
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Marco Onofrio Torres
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Francesca Zanchetta
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Alberta Cecchinato
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Martin Diogo
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Mor Peleg Falb
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Sandro Giannini
- Department of Medicine, Clinica Medica 1, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
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3
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Ungureanu MC, Bilha SC, Hogas M, Velicescu C, Leustean L, Teodoriu LC, Preda C. Preptin: A New Bone Metabolic Parameter? Metabolites 2023; 13:991. [PMID: 37755271 PMCID: PMC10537071 DOI: 10.3390/metabo13090991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/17/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023] Open
Abstract
Preptin is a 34-aminoacid peptide derived from the E-peptide of pro-insulin-like growth factor 2 (pro-IGF2) that is co-secreted with insulin and upregulates glucose-mediated insulin secretion. High serum preptin levels were described in conditions associated with insulin resistance, such as polycystic ovary syndrome and type 2 diabetes mellitus (T2M). Insulin and also IGF2 are known to be anabolic bone hormones. The "sweet bone" in T2M usually associates increased density, but altered microarchitecture. Therefore, preptin was proposed to be one of the energy regulatory hormones that positively impacts bone health. Experimental data demonstrate a beneficial impact of preptin upon the osteoblasts. Preptin also appears to regulate osteocalcin secretion, which in turn regulates insulin sensitivity. Preptin is greatly influenced by the glucose tolerance status and the level of physical exercise, both influencing the bone mass. Clinical studies describe low serum preptin concentrations in osteoporosis in both men and women, therefore opening the way towards considering preptin a potential bone anabolic therapy. The current review addresses the relationship between preptin and bone mass and metabolism in the experimental and clinical setting, also considering the effects of preptin on carbohydrate metabolism and the pancreatic-bone loop.
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Affiliation(s)
- Maria-Christina Ungureanu
- Endocrinology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (M.-C.U.)
| | - Stefana Catalina Bilha
- Endocrinology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (M.-C.U.)
| | - Mihai Hogas
- Physiology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Cristian Velicescu
- Surgery Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Letitia Leustean
- Endocrinology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (M.-C.U.)
| | - Laura Claudia Teodoriu
- Endocrinology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (M.-C.U.)
| | - Cristina Preda
- Endocrinology Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania; (M.-C.U.)
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Potalitsyn P, Mrázková L, Selicharová I, Tencerová M, Ferenčáková M, Chrudinová M, Turnovská T, Brzozowski AM, Marek A, Kaminský J, Jiráček J, Žáková L. Non-glycosylated IGF2 prohormones are more mitogenic than native IGF2. Commun Biol 2023; 6:863. [PMID: 37598269 PMCID: PMC10439913 DOI: 10.1038/s42003-023-05239-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 08/10/2023] [Indexed: 08/21/2023] Open
Abstract
Insulin-like Growth Factor-2 (IGF2) is important for the regulation of human embryonic growth and development, and for adults' physiology. Incorrect processing of the IGF2 precursor, pro-IGF2(156), leads to the formation of two IGF2 proforms, big-IGF2(87) and big-IGF2(104). Unprocessed and mainly non-glycosylated IGF2 proforms are found at abnormally high levels in certain diseases, but their mode of action is still unclear. Here, we found that pro-IGF2(156) has the lowest ability to form its inactivating complexes with IGF-Binding Proteins and has higher proliferative properties in cells than IGF2 and other IGF prohormones. We also showed that big-IGF2(104) has a seven-fold higher binding affinity for the IGF2 receptor than IGF2, and that pro-IGF2(87) binds and activates specific receptors and stimulates cell growth similarly to the mature IGF2. The properties of these pro-IGF2 forms, especially of pro-IGF2(156) and big-IGF2(104), indicate them as hormones that may be associated with human diseases related to the accumulation of IGF-2 proforms in the circulation.
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Affiliation(s)
- Pavlo Potalitsyn
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, 12800, Prague 2, Czech Republic
| | - Lucie Mrázková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, 12800, Prague 2, Czech Republic
| | - Irena Selicharová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Michaela Tencerová
- Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, Prague 4, Czech Republic
| | - Michaela Ferenčáková
- Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, Prague 4, Czech Republic
| | - Martina Chrudinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Tereza Turnovská
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Andrzej Marek Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic
| | - Jiří Jiráček
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic.
| | - Lenka Žáková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 116 10, Prague 6, Czech Republic.
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de Camargo Vieira MC, Gonçalves WRB, Guerra RA, Callegaro FS, Lazaretti-Castro M, Maeda SS. Hepatitis C-Associated Osteosclerosis: Improvement After Treatment with Sofosbuvir, Daclatasvir, and Ibandronate: Case Report and Literature Review. Calcif Tissue Int 2021; 109:104-109. [PMID: 33616713 DOI: 10.1007/s00223-021-00822-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 02/04/2021] [Indexed: 12/22/2022]
Abstract
Hepatitis C-associated osteosclerosis (HCAO) remains a rare condition despite the growing prevalence of hepatitis C virus (HCV) infection worldwide. Since the first case reported in 1992, this is the twenty-second case described. Patients with HCAO present with severe bone pain and elevated serum levels of bone markers, especially alkaline phosphatase (ALP), with increased bone density. We report here the case of a 59-year-old man with generalized bone pain and diagnosis of HCV infection. Biochemical tests showed elevated bone turnover markers, specifically, ALP, carboxy-terminal collagen crosslinks and osteocalcin. Imaging studies revealed generalized bone sclerosis. Bone mineral density was elevated in all validated sites. His clinical symptoms and bone-related findings were attributed to HCAO. He was sequentially treated with cholecalciferol, prednisone, sofosbuvir associated with daclatasvir and ibandronate, and progressed with undetectable viral load after HCV treatment, normalization of ALP levels after introduction of ibandronate, and pain improvement 1 year after discontinuation of the bisphosphonate. Bone pain complaints must be investigated in patients with HCV. HCAO is a differential diagnosis of increased bone mass.
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Affiliation(s)
- Maria Carolina de Camargo Vieira
- Department of Endocrinology, Hospital do Servidor Público Municipal (HSPM), São Paulo, SP, Brazil.
- Department of Medicine, Endocrinology Unit, Federal University of São Paulo (UNIFESP), Rua Estado de Israel, 639, Vila Clementino, São Paulo, SP, CEP 04022-001, Brazil.
| | | | - Ricardo Ayello Guerra
- Department of Endocrinology, Hospital do Servidor Público Municipal (HSPM), São Paulo, SP, Brazil
- Department of Endocrinology, Instituto de Assistência Médica ao Servidor Público Estadual de São Paulo (IAMSPE), São Paulo, SP, Brazil
| | | | - Marise Lazaretti-Castro
- Department of Medicine, Endocrinology Unit, Federal University of São Paulo (UNIFESP), Rua Estado de Israel, 639, Vila Clementino, São Paulo, SP, CEP 04022-001, Brazil
| | - Sergio Setsuo Maeda
- Department of Medicine, Endocrinology Unit, Federal University of São Paulo (UNIFESP), Rua Estado de Israel, 639, Vila Clementino, São Paulo, SP, CEP 04022-001, Brazil
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Nottez A, Kolta S, Lion G, Ternynck C, Legroux-Gérot I, Vantyghem MC, Cortet B, Paccou J. Prevalence and causes of elevated bone mass. Bone 2020; 138:115476. [PMID: 32534222 DOI: 10.1016/j.bone.2020.115476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Reports of elevated bone mass (EBM) on routine DXA scanning are not infrequent. However, epidemiological studies of EBM are few in number and definition thresholds variable. The purpose of this study was to assess the prevalence and causes of EBM in the general population referred to a single university hospital - catering for a population of 4 million inhabitants - for DXA scanning. MATERIAL AND METHODS DXA databases were initially searched for individuals with a bone mineral density (BMD) Z-score ≥+4 at any site in the lumbar spine or hip from April 1st, 2008 to April 30st, 2018. Two Hologic scanners were available at the Lille University Hospital (France). Prevalence of EBM was evaluated, as were causes associated with EBM. RESULTS At the lumbar spine, 18,229 bone density tests were performed in women and 10,209 in men. At the hip, 17,390 tests were performed in women and 9857 in men. The total number of patients who had at least one bone density test was 14,745, of which 64.2% were female. Of these 14,745 patients, 211 had a Z-score ≥+4 at any site, i.e. a prevalence of 1.43% [1.25%-1.64%]. The DXA scans and medical records of 92 men and 119 women with elevated BMD were reviewed to assess causes. An artefactual cause was found in 164 patients (75%) with EBM (mostly degenerative disease of the spine), and an acquired cause of focal EBM was found in only 2 patients, both of whom had sclerotic bone metastases from prostate cancer. An acquired cause of generalized EBM was found in 32 patients (15%), the vast majority of whom had renal osteodystrophy (n = 11), followed by hematological disorders (n = 9; e.g. myeloproliferative syndromes and mastocytosis) and diffuse bone metastases from solid cancer (n = 5). Of the remaining causes, rare hereditary diseases (e.g. osteopetrosis…) and unexplained EBM were found in 10 and 6 cases respectively. CONCLUSION The prevalence of EBM (Z-score ≥+4 at any site) was 1.43% [1.25%-1.64%]. In nearly all instances (97.1%) the explanation for EBM could be found in the medical record and through conventional investigations. This study suggests that the main cause of EBM is degenerative disease of the spine. Further studies are needed to differentiate artefactual EBM from hereditary or acquired EBM, and to investigate unexplained EBM. Genetic testing may prove useful in elucidating rare unknown causes.
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Affiliation(s)
- Aurore Nottez
- Univ. Lille, CHU Lille, Department of Rheumatology, 59000 Lille, France
| | - Sami Kolta
- INSERM UMR-1153, Paris, Department of Rheumatology, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Paris, France; INSERM UMR-1153, Paris, France
| | - Georges Lion
- Univ. Lille, CHU Lille, Department of Nuclear Medicine, 59000 Lille, France
| | - Camille Ternynck
- Univ. Lille, CHU Lille, ULR 2694 - METRICS: Évaluation des Technologies de Santé et des Pratiques Médicales, F-59000 Lille, France
| | - Isabelle Legroux-Gérot
- Univ. Lille, CHU Lille, MABLab ULR 4490, Department of Rheumatology, 59000 Lille, France
| | - Marie-Christine Vantyghem
- Univ. Lille, CHU Lille, Department of Endocrinology, Diabetology, Metabolism, Nutrition, 59000 Lille, France
| | - Bernard Cortet
- Univ. Lille, CHU Lille, MABLab ULR 4490, Department of Rheumatology, 59000 Lille, France
| | - Julien Paccou
- Univ. Lille, CHU Lille, MABLab ULR 4490, Department of Rheumatology, 59000 Lille, France.
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Kazemi M, Jarrett BY, Parry SA, Thalacker-Mercer AE, Hoeger KM, Spandorfer SD, Lujan ME. Osteosarcopenia in Reproductive-Aged Women with Polycystic Ovary Syndrome: A Multicenter Case-Control Study. J Clin Endocrinol Metab 2020; 105:5866600. [PMID: 32614948 PMCID: PMC7418445 DOI: 10.1210/clinem/dgaa426] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/26/2020] [Indexed: 02/07/2023]
Abstract
CONTEXT Osteosarcopenia (loss of skeletal muscle and bone mass and/or function usually associated with aging) shares pathophysiological mechanisms with polycystic ovary syndrome (PCOS). However, the relationship between osteosarcopenia and PCOS remains unclear. OBJECTIVE We evaluated skeletal muscle index% (SMI% = [appendicular muscle mass/weight (kg)] × 100) and bone mineral density (BMD) in PCOS (hyperandrogenism + oligoamenorrhea), and contrasted these musculoskeletal markers against 3 reproductive phenotypes (i): HA (hyperandrogenism + eumenorrhea) (ii); OA (normoandrogenic + oligoamenorrhea) and (iii), controls (normoandrogenic + eumenorrhea). Endocrine predictors of SMI% and BMD were evaluated across the groups. DESIGN, SETTING, AND PARTICIPANTS Multicenter case-control study of 203 women (18-48 years old) in New York State. RESULTS PCOS group exhibited reduced SMI% (mean [95% confidence interval (CI)]; 26.2% [25.1,27.3] vs 28.8% [27.7,29.8]), lower-extremity SMI% (57.6% [56.7,60.0] vs 62.5% [60.3,64.6]), and BMD (1.11 [1.08,1.14] vs 1.17 [1.14,1.20] g/cm2) compared to controls. PCOS group also had decreased upper (0.72 [0.70,0.74] vs 0.77 [0.75,0.79] g/cm2) and lower (1.13 [1.10,1.16] vs 1.19 [1.16,1.22] g/cm2) limb BMD compared to HA. Matsuda index was lower in PCOS vs controls and positively associated with SMI% in all groups (all Ps ≤ 0.05). Only controls showed associations between insulin-like growth factor (IGF) 1 and upper (r = 0.84) and lower (r = 0.72) limb BMD (all Ps < 0.01). Unlike in PCOS, IGF-binding protein 2 was associated with SMI% in controls (r = 0.45) and HA (r = 0.67), and with upper limb BMD (r = 0.98) in HA (all Ps < 0.05). CONCLUSIONS Women with PCOS exhibit early signs of osteosarcopenia when compared to controls likely attributed to disrupted insulin function. Understanding the degree of musculoskeletal deterioration in PCOS is critical for implementing targeted interventions that prevent and delay osteosarcopenia in this clinical population.
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Affiliation(s)
- Maryam Kazemi
- Division of Nutritional Sciences, Human Metabolic Research Unit, Cornell University, Ithaca, NY, US
| | - Brittany Y Jarrett
- Division of Nutritional Sciences, Human Metabolic Research Unit, Cornell University, Ithaca, NY, US
| | - Stephen A Parry
- Cornell Statistical Consulting Unit, Cornell University, Ithaca, NY, US
| | - Anna E Thalacker-Mercer
- Division of Nutritional Sciences, Human Metabolic Research Unit, Cornell University, Ithaca, NY, US
| | - Kathleen M Hoeger
- Department of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, NY, USA
| | - Steven D Spandorfer
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY, US
| | - Marla E Lujan
- Division of Nutritional Sciences, Human Metabolic Research Unit, Cornell University, Ithaca, NY, US
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van Doorn J. Insulin-like growth factor-II and bioactive proteins containing a part of the E-domain of pro-insulin-like growth factor-II. Biofactors 2020; 46:563-578. [PMID: 32026557 PMCID: PMC7497164 DOI: 10.1002/biof.1623] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/15/2020] [Indexed: 12/13/2022]
Abstract
Insulin-like growth factor (IGF)-II is considered to function as an important fetal growth factor, which is structurally and functionally related to IGF-I and proinsulin. At least in vitro, IGF-II actions are mediated through the IGF-I receptor and to a lesser extent the insulin receptor. After birth, the function of IGF-II is less clear although in adults the serum level of IGF-II exceeds that of IGF-I several fold. The IGF-II gene is maternally imprinted, with exception of the liver and several parts of the brain, where it is expressed from both alleles. The regulation, organization, and translation of the IGF-II gene is complex, with five different putative promotors leading to a range of noncoding and coding mRNAs. The 180-amino acid pre-pro-IGF-II translation product can be divided into five domains and include a N-terminal signal peptide of 24 amino acid residues, the 67 amino acid long mature protein, and an 89 residues extension at the COOH terminus, designated as the E-domain. After removal of the signal peptide, the processing of pro-IGF-II into mature IGF-II requires various steps including glycosylation of the E-domain followed by the action of endo-proteases. Several of these processing intermediates can be found in the human circulation. There is increasing evidence that, besides IGF-II, several incompletely processed precursor forms of the protein, and even a 34-amino acid peptide (preptin) derived from the E-domain of pro-IGF-II, exhibit distinct biological activities. This review will focus on the current insights regarding the specific roles of the latter proteins in cancer, glucose homeostasis, and bone physiology. To address this topic clearly in the right context, a concise overview of the biological and biochemical properties of IGF-II and several relevant aspects of the IGF system will be provided.
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Affiliation(s)
- Jaap van Doorn
- Department of Genetics, Section Metabolic DiagnosticsUniversity Medical Center Utrecht, Utrecht UniversityUtrechtThe Netherlands
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A peptide containing the receptor binding site of insulin-like growth factor binding protein-2 enhances bone mass in ovariectomized rats. Bone Res 2018; 6:23. [PMID: 30109160 PMCID: PMC6089876 DOI: 10.1038/s41413-018-0024-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 05/31/2018] [Accepted: 06/15/2018] [Indexed: 12/27/2022] Open
Abstract
Male Igfbp2−/− mice have a significant reduction in bone mass and administration of a peptide that contains the insulin-like growth factor binding protein-2(IGFBP-2) receptor-binding domain stimulates bone formation in these animals. Female Igfbp2−/− mice do not have this phenotype but following ovariectomy (OVX) lose more bone than OVX wild-type mice. This suggests that in the absence of estrogen, IGFBP-2 is required to maintain bone mass. Therefore these studies were undertaken to determine if this peptide could stimulate bone acquisition in OVX rats. OVX rats were divided into seven treatment groups: sham animals, OVX animals, OVX animals receiving a control scrambled peptide, or one of three doses of the active peptide termed PEG-HBD-1 (0.7, 2, and 6 mg·kg-1) and an OVX group receiving parathyroid hormone (PTH) (50 µg·kg-1 per day). The peptides were administered for 8 weeks. DXA revealed a significant reduction in femoral and tibial areal bone mineral density (aBMD) after OVX, whereas treatment with the high-dose peptide increased aBMD by 6.2% ± 2.4% (P < 0.01) compared to control peptide; similar to the increase noted with PTH (5.6% ± 3.0%, P < 0.01). Similar increases were noted with two lower doses of the peptide (3.8% ± 1.5%, P < 0.05 for low dose; 3.1% ± 1.6%, P = 0.07 for middle dose). Micro CT showed that the OVX control peptide animals had reductions of 41% and 64% in femoral trabecular BV/TV and trabecular number, respectively. All three doses of the peptide increased bone volume/total volume (BV/TV) significantly, while the low and middle doses increased trabecular number. Cortical BV/TV and thickness at the midshaft increased significantly with each dose of peptide (18.9% ± 9.8%, P < 0.01 and 14.2% ± 7.9%, P < 0.01 for low dose; 23.7% ± 10.7%, P < 0.001 and 15.8% ± 6.1%, P < 0.001 for middle dose; 19.0% ± 6.9%, P < 0.01 and 16.2% ± 9.7%, P < 0.001 for high dose) and with PTH (25.8% ± 9.2%, P < 0.001 and 19.4% ± 8.8%, P < 0.001). Histomorphometry showed that the lowest dose of peptide stimulated BV/TV, trabecular thickness, mineral apposition rate (MAR), bone formation rate/bone surface (BFR/BS), number of osteoblasts/bone perimeter (N.ob/B.pm), and decreased osteoclast surface/bone perimeter (Oc.S/B.Pm). The highest dose stimulated each of these parameters except MAR and BFR/BS. Thus, the heparin-binding domain receptor region of IGFBP-2 accounts for its anabolic activity in bone. Importantly, this peptide enhances bone mass in estrogen-deficient animals. An experimental peptide stimulates bone acquisition in female rats who have had their ovaries removed, raising the prospect a new drug for osteoporosis. IGFBP-2 is an insulin-like growth factor (IGF) binding protein, which regulates the amount of IGF-I and II that are transported out of the blood and are available to influence the growth and proliferation of bone-producing osteoblasts. Previous studies have suggested that IGFBP-2 is required to maintain bone mass in the absence of estrogen, and that a 13 amino acid peptide (HBD1) from the core of the protein could provide a substitute for it. In this study, David Clemmons at the University of North Carolina at Chapel Hill and his colleagues demonstrate that injecting the peptide into ovariectomized female rats prompts significant increases in bone mass, whereas control animals lost bone.
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10
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Alkharobi HE, Al-Khafaji H, Beattie J, Devine DA, El-Gendy R. Insulin-Like Growth Factor Axis Expression in Dental Pulp Cells Derived From Carious Teeth. Front Bioeng Biotechnol 2018; 6:36. [PMID: 29707538 PMCID: PMC5906522 DOI: 10.3389/fbioe.2018.00036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/15/2018] [Indexed: 01/03/2023] Open
Abstract
The insulin-like growth factor (IGF) axis plays an important role in dental tissue regeneration and most components of this axis are expressed in human dental pulp cells (DPCs). In our previous study, we analyzed IGF axis gene expression in DPCs and demonstrated a novel role of IGF binding protein (IGFBP)-2 and -3 in coordinating mineralized matrix formation in differentiating DPCs. A more recent study from our laboratory partially characterized dental pulp stem cells from teeth with superficial caries (cDPCs) and showed that their potential to differentiate odontoblasts and/or into osteoblasts is enhanced by exposure to the mild inflammatory conditions characteristic of superficial caries. In the present study, we examine whether changes apparent in IGF axis expression during osteogenic differentiation of healthy DPCs are also apparent in DPCs derived from carious affected teeth.
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Affiliation(s)
- Hanaa Esa Alkharobi
- Division of Oral Biology, Leeds School of Dentistry, St James University Hospital, University of Leeds, Leeds, United Kingdom.,Department of Oral Biology, Faculty of Dentistry, King Abdul Aziz University, Jeddah, Saudi Arabia
| | - Hasanain Al-Khafaji
- Division of Oral Biology, Leeds School of Dentistry, St James University Hospital, University of Leeds, Leeds, United Kingdom.,Department of Oral Biology, Faculty of Dentistry, King Abdul Aziz University, Jeddah, Saudi Arabia
| | - James Beattie
- Division of Oral Biology, Leeds School of Dentistry, St James University Hospital, University of Leeds, Leeds, United Kingdom
| | - Deirdre Ann Devine
- Division of Oral Biology, Leeds School of Dentistry, St James University Hospital, University of Leeds, Leeds, United Kingdom
| | - Reem El-Gendy
- Division of Oral Biology, Leeds School of Dentistry, St James University Hospital, University of Leeds, Leeds, United Kingdom.,Department of Oral Pathology, Faculty of Dentistry, Suez Canal University, Ismailia, Egypt
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11
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Miyamura N, Nishida S, Itasaka M, Matsuda H, Ohtou T, Yamaguchi Y, Inaba D, Tamiya S, Nakano T. A case of hepatitis C-associated osteosclerosis: accelerated bone turnover controlled by pulse steroid therapy. Endocrinol Diabetes Metab Case Rep 2016; 2016:EDM160097. [PMID: 27933174 PMCID: PMC5118973 DOI: 10.1530/edm-16-0097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/26/2016] [Indexed: 11/08/2022] Open
Abstract
Hepatitis C-associated osteosclerosis (HCAO), a very rare disorder in which an extremely rapid bone turnover occurs and results in osteosclerosis, was acknowledged in 1990s as a new clinical entity with the unique bone disorder and definite link to chronic type C hepatitis, although the pathogenesis still remains unknown. Affected patients suffer from excruciating deep bone pains. We report the 19th case of HCAO with diagnosis confirmed by bone biopsy, and treated initially with a bisphosphonate, next with corticosteroids and finally with direct acting antivirals (DAA: sofosbuvir and ribavirin) for HCV infection. Risedronate, 17.5 mg/day for 38 days, did not improve the patient’s symptoms or extremely elevated levels of bone markers, which indicated hyper-bone-formation and coexisting hyper-bone-resorption in the patient. Next, intravenous methylprednisolone pulse therapy followed by high-dose oral administration of prednisolone evidently improved them. DAA therapy initiated after steroid therapy successfully achieved sustained virological response, but no additional therapeutic effect on them was observed. Our results strongly suggested that the underlying immunological alteration is the crucial key to clarify the pathogenesis of HCAO. Bone mineral density of lumbar vertebrae of the patient was increased by 14% in four-month period of observation. Clarification of the mechanisms that develop osteosclerosis in HCAO might lead to a new therapeutic perspective for osteoporosis.
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Affiliation(s)
| | | | | | | | | | | | - Daisuke Inaba
- Orthopedic Surgery , Tamana Central Hospital, Tamana , Japan
| | - Sadahiro Tamiya
- Department of General and Community Medicine , Kumamoto University Hospital, Kumamoto , Japan
| | - Tetsuo Nakano
- Orthopedic Surgery , Tamana Central Hospital, Tamana , Japan
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12
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Conover CA. Discrepancies in insulin-like growth factor signaling? No, not really. Growth Horm IGF Res 2016; 30-31:42-44. [PMID: 27792888 DOI: 10.1016/j.ghir.2016.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/03/2016] [Accepted: 10/21/2016] [Indexed: 01/03/2023]
Abstract
Why do studies on insulin-like growth factors (IGFs) and IGF signaling seem so contradictory? The answer is "It depends". This mini- review will explore a few of the factors that are likely to contribute to a seemingly confusing message. Most of the evidence comes from experimental animal models.
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Affiliation(s)
- Cheryl A Conover
- Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
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13
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Transcriptional profiling of chronic clinical hepatic schistosomiasis japonica indicates reduced metabolism and immune responses. Parasitology 2015. [PMID: 26216487 DOI: 10.1017/s0031182015000682] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Schistosomiasis is a significant cause of human morbidity and mortality. We performed a genome-wide transcriptional survey of liver biopsies obtained from Chinese patients with chronic schistosomiasis only, or chronic schistosomiasis with a current or past history of viral hepatitis B. Both disease groups were compared with patients with no prior history or indicators of any liver disease. Analysis showed in the main, downregulation in gene expression, particularly those involved in signal transduction via EIF2 signalling and mTOR signalling, as were genes associated with cellular remodelling. Focusing on immune associated pathways, genes were generally downregulated. However, a set of three genes associated with granulocytes, MMP7, CLDN7, CXCL6 were upregulated. Differential gene profiles unique to schistosomiasis included the gene Granulin which was decreased despite being generally considered a marker for liver disease, and IGBP2 which is associated with increased liver size, and was the most upregulated gene in schistosomiasis only patients, all of which presented with hepatomegaly. The unique features of gene expression, in conjunction with previous reports in the murine model of the cellular composition of granulomas, granuloma formation and recovery, provide an increased understanding of the molecular immunopathology and general physiological processes underlying hepatic schistosomiasis.
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14
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Becker MA, Haluska P, Bale LK, Oxvig C, Conover CA. A novel neutralizing antibody targeting pregnancy-associated plasma protein-a inhibits ovarian cancer growth and ascites accumulation in patient mouse tumorgrafts. Mol Cancer Ther 2015; 14:973-81. [PMID: 25695953 DOI: 10.1158/1535-7163.mct-14-0880] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 02/10/2015] [Indexed: 12/16/2022]
Abstract
The majority of ovarian cancer patients acquire resistance to standard platinum chemotherapy and novel therapies to reduce tumor burden and ascites accumulation are needed. Pregnancy-associated plasma protein-A (PAPP-A) plays a key role in promoting insulin-like growth factor (IGF) pathway activity, which directly correlates to ovarian cancer cell transformation, growth, and invasiveness. Herein, we evaluate PAPP-A expression in tumors and ascites of women with ovarian cancer, and determine the antitumor efficacy of a neutralizing monoclonal PAPP-A antibody (mAb-PA) in ovarian cancer using primary patient ovarian tumorgrafts ("Ovatars"). PAPP-A mRNA expression in patient ovarian tumors correlated with poor outcome and was validated as a prognostic surrogate in Ovatar tumors. Following confirmation of mAb-PA bioavailability and target efficacy in vivo, the antitumor efficacy of mAb-PA in multiple Ovatar tumor models was examined and the response was found to depend on PAPP-A expression. Strikingly, the addition of mAb-PA to standard platinum chemotherapy effectively sensitized platinum-resistant Ovatar tumors. PAPP-A protein in ascites was also assessed in a large cohort of patients and very high levels were evident across the entire sample set. Therefore, we evaluated targeted PAPP-A inhibition as a novel approach to managing ovarian ascites, and found that mAb-PA inhibited the development, attenuated the progression, and induced the regression of Ovatar ascites. Together, these data indicate PAPP-A as a potential palliative and adjunct therapeutic target for women with ovarian cancer.
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Affiliation(s)
- Marc A Becker
- Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota
| | - Paul Haluska
- Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota
| | - Laurie K Bale
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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15
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Serraino C, Melchio R, Silvestri A, Borretta V, Pomero F, Fenoglio L. Hepatitis C-associated osteosclerosis: a new case with long-term follow-up and a review of the literature. Intern Med 2015; 54:777-83. [PMID: 25832941 DOI: 10.2169/internalmedicine.54.3448] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatitis C-associated osteosclerosis (HCAO) is an uncommon condition characterized by increased bone density, skeletal pain and elevated bone formation markers. Since 1992, only 17 cases have been reported. We herein describe the case of a 61-year-old woman affected by severe pain involving the lower limbs. The laboratory data showed an elevated serum alkaline phosphatase level, and the patient was found to be seropositive for hepatitis C virus infection. In addition, an X-ray skeleton survey showed marked cortical thickening of both femurs and tibias, and a whole-body bone scan revealed an increased cortical radionuclide uptake in the involved bones. These findings were consistent with a diagnosis of HCAO. In this report, we discuss the patient's clinical course over 16 years and, for the first time, show a normalized radioisotope uptake on bone scanning 10 years after the diagnosis.
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Affiliation(s)
- Cristina Serraino
- Department of Internal Medicine, S. Croce e Carle General Hospital, Cuneo, Italy
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16
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An uncommon cause of acquired osteosclerosis in adults: hepatitis C-associated osteosclerosis. Skeletal Radiol 2014; 43:1313-8. [PMID: 24719041 DOI: 10.1007/s00256-014-1882-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/27/2014] [Accepted: 03/23/2014] [Indexed: 02/02/2023]
Abstract
Hepatitis C-associated osteosclerosis (HCAO) is a rare sclerosing bone condition characterized by debilitating, predominantly lower extremity bone pain, accelerated bone turnover, and a generalized increase in histologically normal trabecular and cortical bone tissue. Herein we report the clinical presentation and imaging results of the 19th case of HCAO. Clinicians, particularly those caring for a population at risk for HCV infection, should be aware of this uncommon condition. The etio-pathogenesis of HCAO remains obscure but may bear important lessons in bone biology that could lead to new treatment options for osteoporosis.
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17
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Livingstone C, Borai A. Insulin-like growth factor-II: its role in metabolic and endocrine disease. Clin Endocrinol (Oxf) 2014; 80:773-81. [PMID: 24593700 DOI: 10.1111/cen.12446] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 02/26/2014] [Accepted: 02/27/2014] [Indexed: 10/25/2022]
Abstract
Insulin-like growth factor-II (IGF-II) is a widely expressed 7·5 kDa mitogenic peptide hormone. Although it is abundant in serum, understanding of its physiological role is limited compared with that of IGF-I. IGF-II regulates foetal development and differentiation, but its role in adults is less well understood. Evidence suggests roles in a number of tissues including skeletal muscle, adipose tissue, bone and ovary. Altered IGF-II expression has been observed in metabolic conditions, notably obesity, diabetes and the polycystic ovary syndrome. This article summarizes what is known about the actions of IGF-II and its dysregulation in metabolic and endocrine diseases. The possible causes and consequences of dysregulation are discussed along with the implications for diagnostic tests and future research.
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Affiliation(s)
- Callum Livingstone
- Peptide Hormones Supraregional Assay Service (SAS), Department of Clinical Biochemistry, Royal Surrey County Hospital NHS Trust, Guildford, UK; Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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Lund J, Søndergaard MT, Conover CA, Overgaard MT. Heparin-binding mechanism of the IGF2/IGF-binding protein 2 complex. J Mol Endocrinol 2014; 52:345-55. [PMID: 24604839 DOI: 10.1530/jme-13-0184] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
IGF1 and IGF2 are potent stimulators of diverse cellular activities such as differentiation and mitosis. Six IGF-binding proteins (IGFBP1-IGFBP6) are primary regulators of IGF half-life and receptor availability. Generally, the binding of IGFBPs inhibits IGF receptor activation. However, it has been shown that IGFBP2 in complex with IGF2 (IGF2/IGFBP2) stimulates osteoblast function in vitro and increases skeletal mass in vivo. IGF2 binding to IGFBP2 greatly increases the affinity for 2- or 3-carbon O-sulfated glycosaminoglycans (GAGs), e.g. heparin and heparan sulfate, which is hypothesized to preferentially and specifically target the IGF2/IGFBP2 complex to the bone matrix. In order to obtain a more detailed understanding of the interactions between the IGF2/IGFBP2 complex and GAGs, we investigated heparin-binding properties of IGFBP2 and the IGF2/IGFBP2 complex in a quantitative manner. For this study, we mutated key positively charged residues within the two heparin-binding domains (HBDs) in IGFBP2 and in one potential HBD in IGF2. Using heparin affinity chromatography, we demonstrate that the two IGFBP2 HBDs contribute differentially to GAG binding in free IGFBP2 and the IGF2/IGFBP2 protein complex. Moreover, we identify a significant contribution from the HBD in IGF2 to the increased IGF2/IGFBP2 heparin affinity. Using molecular modeling, we present a novel model for the IGF2/IGFBP2 interaction with heparin where all three proposed HBDs constitute a positively charged and surface-exposed area that would serve to promote the increased heparin affinity of the complex compared with free intact IGFBP2.
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Affiliation(s)
- Jacob Lund
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Mads T Søndergaard
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Cheryl A Conover
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Michael T Overgaard
- Department of BiotechnologyChemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, DenmarkDivision of EndocrinologyEndocrine Research Unit, Mayo Clinic, Rochester, Minnesota, USA
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19
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Dynkevich Y, Rother KI, Whitford I, Qureshi S, Galiveeti S, Szulc AL, Danoff A, Breen TL, Kaviani N, Shanik MH, Leroith D, Vigneri R, Koch CA, Roth J. Tumors, IGF-2, and hypoglycemia: insights from the clinic, the laboratory, and the historical archive. Endocr Rev 2013; 34:798-826. [PMID: 23671155 DOI: 10.1210/er.2012-1033] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Tumors of mesenchymal and epithelial origin produce IGF-2, which activates pathways in the tumors. In a minority of patients, the tumors (hepatomas, fibromas, and fibrosarcomas are the most common among many) release into the circulation enough IGF-2-related peptides to mimic the fasting hypoglycemia characteristic of patients with insulin-producing islet-cell tumors. Rarely, markedly elevated IGF-2 levels produce somatic changes suggestive of acromegaly. Typically, the elevated IGF-2 levels are associated with suppressed plasma levels of insulin, IGF-1, and GH. Complicating the pathophysiology are the IGF binding proteins (IGFBPs) that can bind IGF-2 and IGF-1, modifying hormone metabolism and action. IGFBP concentrations are often altered in the presence of these tumors. At the cellular level, the 3 hormone-related ligands, IGF-2, IGF-1, and insulin, all bind to 4 (or more) types of IGF-1 receptor (IGF-1R) and insulin receptor (IR). Each receptor has its own characteristic affinity for each ligand, a tyrosine kinase, and overlapping profiles of action in the target cells. The IGF-2R, in addition to binding mannose-6-phosphate-containing proteins, provides an IGF-2 degradation pathway. Recent evidence suggests IGF-2R involvement also in signal transduction. Surgery, the treatment of choice, can produce a cure. For patients not cured by surgery, multiple therapies exist, for the tumor and for hypoglycemia. Potential future therapeutic approaches are sketched. From 1910 to 1930, hypoglycemia, insulin, insulinomas, and non-islet-cell tumors were recognized. The latter third of the century witnessed the emergence of the immunoassay for insulin; the IGFs, their binding proteins, and assays to measure them; and receptors for the insulin-related peptides as well as the intracellular pathways beyond the receptor. In closing, we replace non-islet-cell tumor hypoglycemia, an outdated and misleading label, with IGF-2-oma, self-explanatory and consistent with names of other hormone-secreting tumors.
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Affiliation(s)
- Yevgeniya Dynkevich
- MD, FACP, Investigator, Feinstein Institute for Medical Research, Laboratory of Diabetes and Diabetes-Related Research, 350 Community Drive, Manhasset, NY 11030.
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20
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Orsini LGS, Pinheiro MM, Castro CHM, Silva AEB, Szejnfeld VL. Bone mineral density measurements, bone markers and serum vitamin D concentrations in men with chronic non-cirrhotic untreated hepatitis C. PLoS One 2013; 8:e81652. [PMID: 24312334 PMCID: PMC3842940 DOI: 10.1371/journal.pone.0081652] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 10/15/2013] [Indexed: 01/01/2023] Open
Abstract
Introduction The high prevalence of chronic hepatitis C (CHC) and its consequent cirrhosis has been associated with bone fragility. Whether CHC may cause bone and mineral abnormalities in the absence of hepatocellular dysfunction is still unknown. In this study we aimed to determine the prevalence of osteoporotic vertebral fractures and low BMD measurements in men with non-cirrhotic CHC. Risk factors for low BMD and fractures were also investigated. Methods Morphometric vertebral fractures and BMD measurements were performed in 60 non-cirrhotic untreated men with CHC and 59 healthy controls, matched for age and gender, weight and current smoking. Serum CTx, calcium, phosphate, intact PTH, alkaline phosphatase and vitamin D (25OHD) concentrations were measured in all participants. Clinical risk factors for low BMD and fractures were evaluated by a structured questionnaire as well as details regarding HCV infection. Results Trochanter and total femur BMD were significantly lower in CHC patients as compared to healthy men (p = 0.04). In men 50 years and older, the prevalence of osteoporosis was significantly higher among CHC patients (p = 0.01). Lower levels of physical activities and more often report of prolonged immobilization were observed among CHC patients (p<0.05). Liver inflammation and fibrosis, viral load and genotype did not correlate with BMD measurements. Bone markers and 25OHD concentrations were similar in both groups. Only a few vertebral fractures were observed. Conclusions Our results demonstrate that non-cirrhotic untreated CHC patients have lower BMD at the femur as compared to healthy men in spite of the absence of significant bone and mineral abnormalities.
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Affiliation(s)
- Luciana G. S. Orsini
- Rheumatology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina (Unifesp/EPM), São Paulo, Brazil
| | - Marcelo M. Pinheiro
- Rheumatology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina (Unifesp/EPM), São Paulo, Brazil
| | - Charlles H. M. Castro
- Rheumatology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina (Unifesp/EPM), São Paulo, Brazil
- * E-mail:
| | - Antônio E. B. Silva
- Gastroenterology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina (Unifesp/EPM), São Paulo, Brazil
| | - Vera L. Szejnfeld
- Rheumatology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina (Unifesp/EPM), São Paulo, Brazil
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21
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Gregson CL, Hardcastle SA, Cooper C, Tobias JH. Friend or foe: high bone mineral density on routine bone density scanning, a review of causes and management. Rheumatology (Oxford) 2013; 52:968-85. [PMID: 23445662 DOI: 10.1093/rheumatology/ket007] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A finding of high BMD on routine DXA scanning is not infrequent and most commonly reflects degenerative disease. However, BMD increases may also arise secondary to a range of underlying disorders affecting the skeleton. Although low BMD increases fracture risk, the converse may not hold for high BMD, since elevated BMD may occur in conditions where fracture risk is increased, unaffected or reduced. Here we outline a classification for the causes of raised BMD, based on identification of focal or generalized BMD changes, and discuss an approach to guide appropriate investigation by clinicians after careful interpretation of DXA scan findings within the context of the clinical history. We will also review the mild skeletal dysplasia associated with the currently unexplained high bone mass phenotype and discuss recent advances in osteoporosis therapies arising from improved understanding of rare inherited high BMD disorders.
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Affiliation(s)
- Celia L Gregson
- Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Bristol, UK.
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22
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Lương KVQ, Nguyễn LTH. Theoretical basis of a beneficial role for vitamin D in viral hepatitis. World J Gastroenterol 2012; 18:5338-50. [PMID: 23082050 PMCID: PMC3471102 DOI: 10.3748/wjg.v18.i38.5338] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/22/2012] [Accepted: 05/06/2012] [Indexed: 02/06/2023] Open
Abstract
Abnormal bone metabolism and dysfunction of the calcium-parathyroid hormone-vitamin D axis have been reported in patients with viral hepatitis. Some studies suggested a relationship between vitamin D and viral hepatitis. Genetic studies have provided an opportunity to identify the proteins that link vitamin D to the pathology of viral hepatitis (i.e., the major histocompatibility complex class II molecules, the vitamin D receptor, cytochrome P450, the renin-angiotensin system, apolipoprotein E, liver X receptor, toll-like receptor, and the proteins regulated by the Sp1 promoter gene). Vitamin D also exerts its effects on viral hepatitis via non-genomic factors, i.e., matrix metalloproteinase, endothelial vascular growth factor, prostaglandins, cyclooxygenase-2, and oxidative stress. In conclusion, vitamin D could have a beneficial role in viral hepatitis. Calcitriol is best used for viral hepatitis because it is the active form of the vitamin D3 metabolite.
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Bikle DD, Wang Y. Insulin like growth factor-I: a critical mediator of the skeletal response to parathyroid hormone. Curr Mol Pharmacol 2012; 5:135-142. [PMID: 21787292 PMCID: PMC3690777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/16/2010] [Accepted: 03/03/2011] [Indexed: 05/31/2023]
Abstract
This review focuses on the mechanisms by which PTH stimulates both osteoblast and osteoclast function, emphasizing the critical role that IGF-I plays in these processes. After reviewing the current literature on the skeletal actions of PTH and the modulation of IGF action on bone by the different IGF-binding proteins, the review then examines studies from mouse models in which IGF-I or its receptor have been selectively deleted in different cells of the skeletal system, in particular osteoprogenitors, mature osteoblasts, and osteoclasts. Mice in which IGF-I production has been deleted from all cells are deficient in both bone formation and bone resorption with few osteoblasts or osteoclasts in bone in vivo, reduced osteoblast colony forming units, and an inability of either the osteoblasts or osteoclast precursors to support osteoclastogenesis in vitro. Mice in which the IGF-I receptor is specifically deleted in mature osteoblasts have a mineralization defect in vivo, and bone marrow stromal cells from these mice fail to mineralize in vitro. Mice in which the IGF-I receptor is deleted in osteoprogenitor cells have a marked reduction in osteoblast proliferation and differentiation leading to osteopenia. Finally mice lacking the IGF-I receptor in their osteoclasts have increased bone and decreased osteoclast formation. PTH fails to stimulate bone formation in the mice lacking IGF-I or its receptor in osteoblasts or enhance the signaling between osteoblasts and osteoclasts through RANKL/RANK and Ephrin B2/Eph B4, emphasizing the role IGF-I signaling plays in cell-communication per se and as stimulated by PTH.
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Affiliation(s)
- Daniel D Bikle
- Veterans Affairs Medical Center and University of California, San Francisco, San Francisco, CA 94121, USA.
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24
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Kawai M, Rosen CJ. The insulin-like growth factor system in bone: basic and clinical implications. Endocrinol Metab Clin North Am 2012; 41:323-33, vi. [PMID: 22682633 PMCID: PMC3576021 DOI: 10.1016/j.ecl.2012.04.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The insulin-like growth factor (IGF) regulatory system is critical for skeletal growth and maintenance. Initially there was great hope that the recombinant IGFs might be used clinically for disorders ranging from short stature to fracture repair and osteoporosis. Although this potential was not realized, basic and translational studies have continued, providing significant insights into the role of this family of growth factors in skeletal homeostasis and the pathophysiology of several bone disorders. This article reviews the importance of the IGF regulatory system in skeletal growth and maintenance.
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Affiliation(s)
- Masanobu Kawai
- Department of Bone and Mineral Research, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan 594-1101
| | - Clifford J. Rosen
- Center for Translational Research, Maine Medical Center Research Institute, Scarborough, ME 04074, USA
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25
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Woeckel VJ, Eijken M, van de Peppel J, Chiba H, van der Eerden BCJ, van Leeuwen JPTM. IFNβ impairs extracellular matrix formation leading to inhibition of mineralization by effects in the early stage of human osteoblast differentiation. J Cell Physiol 2012; 227:2668-76. [PMID: 21898404 DOI: 10.1002/jcp.23009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Osteoimmunology is an emerging field of research focused on the interaction of the immune system and bone. In this study we demonstrate that human osteoblasts are sensitive to the immune cytokine interferon (IFN)β. Osteoblasts respond to IFNβ as shown by the induction of several known IFN target genes such as interferon-induced (IFI) proteins (IFIT1, IFI44L), interferon-stimulated gene factor 3 (ISGF3) complex and the induction of IFNβ itself. We demonstrated that IFNβ has severe inhibitory effects on mineralization of osteoblast-derived extracellular matrix (ECM). Analysis of the timing of the IFNβ effects revealed that committed osteoblasts in early stage of differentiation are most sensitive to IFNβ inhibition of mineralization. A single IFNβ treatment was as effective as multiple treatments. During the progress of differentiation osteoblasts become desensitized for IFNβ. This pinpoints to a complex pattern of IFNβ sensitivity in osteoblasts. Focusing on early osteoblasts, we showed that IFNβ decreased gene expression of ECM-related genes, such as type I Collagen (COL1A1), fibronectin (FN1), fibullin (FBLN1), fibrillin (FBN2), and laminin (LAMA1). Additionally, ECM produced by IFNβ-treated osteoblasts contained less collagen protein. IFNβ stimulated gene expression of osteopontin (OPN), annexin2 (ANXA2), and hyaluronan synthase 1 (HAS1), which are important factors in the adhesion of hematopoietic stem cells (HSC) in the HSC niche. In conclusion, IFNβ directly modifies human osteoblast function by inhibiting ECM synthesis eventually resulting in delayed bone formation and mineralization and induces a HSC niche supporting phenotype. These effects are highly dependent on timing of treatment in the early phase of osteoblast differentiation.
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Affiliation(s)
- V J Woeckel
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
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DeMambro VE, Maile L, Wai C, Kawai M, Cascella T, Rosen CJ, Clemmons D. Insulin-like growth factor-binding protein-2 is required for osteoclast differentiation. J Bone Miner Res 2012; 27:390-400. [PMID: 22006816 PMCID: PMC3385417 DOI: 10.1002/jbmr.545] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Global deletion of the Igfbp2 gene results in the suppression of bone turnover. To investigate the role of insulin-like growth factor-binding protein-2 (IGFBP-2) in regulating osteoclast differentiation, we cultured Igfbp2(-/-) bone marrow cells and found a reduction in the number of osteoclasts and impaired resorption. Addition of full-length IGFBP-2 restored osteoclast differentiation, fusion, and resorption. To determine the molecular domains of IGFBP-2 that were required for this effect to be manifest, Igfbp2(-/-) bone marrow cells were transfected with constructs in which the heparin-binding (HBD) or the IGF-binding domains of IGFBP-2 were mutated. We found that both domains were necessary for osteoclastogenesis because expression of the mutated forms of either domain failed to support the formation of functionally mature osteoclasts. To discern the mechanism by which IGFBP-2 regulates osteoclast formation, PTEN abundance and phosphorylation status as well as AKT responsiveness to IGF-I were analyzed. Igfbp2(-/-) cells had elevated levels of PTEN and phospho-PTEN compared with controls. Expression of wild-type IGFBP-2 reduced the level of PTEN to that of wild-type cells. Cells expressing the IGF-binding mutant showed suppression of PTEN and phospho-PTEN equivalent to the wild-type protein, whereas those expressing the IGFBP-2 HBD mutant showed no PTEN suppression. When the ability of IGF-I to stimulate AKT activation, measured by Thr³⁰⁸ and Ser⁴⁷³ phosphorylation, was analyzed, stimulation of Ser⁴⁷³ in response to IGF-I in preosteoclasts required the presence of intact IGFBP-2. This effect was duplicated by the addition of a CK2 inhibitor that prevents the phosphorylation of PTEN. In contrast, in fully differentiated osteoclasts, stimulation of Thr³⁰⁸ phosphorylation required the presence of intact IGFBP-2. We conclude that IGFBP-2 is an important regulator of osteoclastogenesis and that both the heparin- and the IGF-binding domains of IGFBP-2 are essential for the formation of fully differentiated and functional osteoclasts.
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A case of hepatitis C-associated osteosclerosis that was improved with the combination therapy of peginterferon alfa-2b and ribavirin. Clin J Gastroenterol 2011; 4:255-261. [PMID: 26189530 DOI: 10.1007/s12328-011-0228-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 04/10/2011] [Indexed: 10/18/2022]
Abstract
Hepatitis C-associated osteosclerosis (HCAO) is a rare disorder characterized by a marked increase in skeletal mass in patients who are infected with hepatitis C virus (HCV). The clinical presentation is an acquired deep bone pain with increased serum alkaline phosphatase (ALP) activity. We present a case of a patient with HCAO who was treated with antiviral therapy. A 42-year-old Japanese man presented with severe, stabbing pain in his lower limbs. He was diagnosed with hepatitis C secondary to intravenous drug use 20 years earlier. Serum biochemical studies revealed markedly elevated ALP activity and osteocalcin levels. Skeletal radiographs showed diffuse bony sclerosis with marked cortical thickening in the long bones. The bony findings and clinical symptoms were attributed to HCAO. The HCV RNA viral load was high and the genotype was 2a. The patient was treated with peginterferon alfa-2b and ribavirin for 24 weeks. After 24 weeks of the combination therapy, the patient had a sustained virological response and clinical remission of bone pain and a decrease in the level of serum ALP. In conclusion, HCAO was improved by the combination therapy of peginterferon alfa-2b and ribavirin when the patient achieved sustained virological response. It was confirmed that HCAO was one of the extrahepatic manifestations of HCV.
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Skeletal recovery from hepatitis C-associated osteosclerosis (HCAO) following antiviral treatment. Joint Bone Spine 2011; 78:409-11. [PMID: 21498104 DOI: 10.1016/j.jbspin.2011.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/15/2011] [Indexed: 11/23/2022]
Abstract
Hepatitis C-associated osteosclerosis (HCAO) is characterized by increased bone mass following hepatitis C infection. We report here a case of HCAO that lasted 8 years before the patient received antiviral hepatitis treatment. Seven years after the antiviral treatment, the evolution of radiographs and densitometry showed skeletal recovery of osteosclerosis. This case strengthens the relationship between viral infection and osteosclerosis.
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Kawai M, Breggia AC, DeMambro VE, Shen X, Canalis E, Bouxsein ML, Beamer WG, Clemmons DR, Rosen CJ. The heparin-binding domain of IGFBP-2 has insulin-like growth factor binding-independent biologic activity in the growing skeleton. J Biol Chem 2011; 286:14670-80. [PMID: 21372140 DOI: 10.1074/jbc.m110.193334] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-like growth factor-binding protein 2 (IGFBP-2) is a member of a family of six highly conserved IGFBPs that are carriers for the insulin-like growth factors (IGFs). IGFBP-2 levels rise during rapid neonatal growth and at the time of peak bone acquisition. In contrast, Igfbp2(-/-) mice have low bone mass accompanied by reduced osteoblast numbers, low bone formation rates, and increased PTEN expression. In the current study, we postulated that IGFBP-2 increased bone mass partly through the activity of its heparin-binding domain (HBD). We synthesized a HBD peptide specific for IGFBP-2 and demonstrated in vitro that it rescued the mineralization phenotype of Igfbp2(-/-) bone marrow stromal cells and calvarial osteoblasts. Consistent with its cellular actions, the HBD peptide ex vivo stimulated metacarpal periosteal expansion. Furthermore, administration of HBD peptide to Igfbp2(-/-) mice increased osteoblast number, suppressed marrow adipogenesis, restored trabecular bone mass, and reduced bone resorption. Skeletal rescue in the Igfbp2(-/-) mice was characterized by reduced PTEN expression followed by enhanced Akt phosphorylation in response to IGF-I and increased β-catenin signaling through two mechanisms: 1) stimulation of its cytosolic accumulation and 2) increased phosphorylation of serine 552. We conclude that the HBD peptide of IGFBP-2 has anabolic activity by activating IGF-I/Akt and β-catenin signaling pathways. These data support a growing body of evidence that IGFBP-2 is not just a transport protein but rather that it functions coordinately with IGF-I to stimulate growth and skeletal acquisition.
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Affiliation(s)
- Masanobu Kawai
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
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Kawai M, Rosen CJ. The IGF-I regulatory system and its impact on skeletal and energy homeostasis. J Cell Biochem 2011; 111:14-9. [PMID: 20506515 DOI: 10.1002/jcb.22678] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Insulin-like growth factor (IGF)-I is important in the acquisition and maintenance of both soft and hard tissues. Skeletal remodeling requires energy and recent work has demonstrated that bone can influence insulin sensitivity and thereby regulate metabolic processes. New insights from mouse models into the role of IGF-binding proteins (IGFBPs) as more than mere depots for the IGFs has reignited investigations into the metabolic targets influenced by the IGF regulatory system and the pathways that link bone to adipose tissue. Although there remains continued uncertainty about the relative balance between the effects of circulating versus tissue IGF-I actions, the role of the IGFBPs has been redefined both as modulators of IGF-I action and as independent signaling factors. This review highlights several recent findings that shed new light on the physiologic role of the IGF regulatory system and its influence on skeletal and fat metabolism.
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Affiliation(s)
- Masanobu Kawai
- Center for Translational Research, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
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Kawai M, Mödder UI, Khosla S, Rosen CJ. Emerging therapeutic opportunities for skeletal restoration. Nat Rev Drug Discov 2011; 10:141-56. [PMID: 21283108 PMCID: PMC3135105 DOI: 10.1038/nrd3299] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Osteoporosis, a syndrome characterized by thin bones and fractures, has become more prevalent in both women and men. Established therapies for treating this disorder consist primarily of drugs that prevent bone loss, such as the bisphosphonates and selective oestrogen receptor modulators. Although these drugs have been shown to reduce fractures in randomized trials, there is an urgent need for treatments that could lower fracture risk further without additional adverse effects. The introduction of parathyroid hormone (teriparatide), which significantly increases bone mineral density, albeit for a relatively short duration, raised expectations that drugs that stimulate bone formation might cure osteoporosis. After outlining current approaches for treating osteoporosis, this Review focuses on emerging therapeutic opportunities for osteoporosis that are based on recent insights into skeletal physiology. Such novel strategies offer promise not only for reducing age-related bone loss and the associated risk of fractures but also for restoring bone mineral density to healthy levels.
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Affiliation(s)
- Masanobu Kawai
- Center for clinical and translational research, Maine Medical Center Research Institute, Scarborough, Maine, USA
- Department of Bone and Mineral research, Osaka medical center and research institute for maternal and child health, Izumi, Osaka, Japan
| | | | | | - Clifford J Rosen
- Center for clinical and translational research, Maine Medical Center Research Institute, Scarborough, Maine, USA
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Hataya Y, Komatsu Y, Chusho H, Kirishima T, Shintani H, Morimoto T. A case of hepatitis C-associated osteosclerosis with xanthogranulomatous cholecystitis. Intern Med 2011; 50:1703-8. [PMID: 21841329 DOI: 10.2169/internalmedicine.50.4675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
A 62-year-old woman presented with a markedly increased serum ALP level of skeletal origin during a regular follow-up of chronic hepatitis C. Serum calcium, phosphorus, and intact-PTH levels were normal and bone turnover markers were increased. Her generalized bone density was diffusely increased. These findings were consistent with hepatitis C-associated osteosclerosis (HCAO). She underwent cholecystectomy, as gallbladder cancer was suspected; however, histopathological findings demonstrated xanthogranulomatous cholecystitis. After cholecystectomy, serum ALP level and bone turnover markers were gradually decreased. This may indicate the existence of a novel osteogenic factor in the gallbladder in HCAO.
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Affiliation(s)
- Yuji Hataya
- Department of Endocrinology, Kyoto City Hospital, Japan.
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Hamidouche Z, Fromigué O, Ringe J, Häupl T, Marie PJ. Crosstalks between integrin alpha 5 and IGF2/IGFBP2 signalling trigger human bone marrow-derived mesenchymal stromal osteogenic differentiation. BMC Cell Biol 2010; 11:44. [PMID: 20573191 PMCID: PMC2901205 DOI: 10.1186/1471-2121-11-44] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 06/23/2010] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The potential of mesenchymal stromal cells (MSCs) to differentiate into functional bone forming cells provides an important tool for bone regeneration. The identification of factors that trigger osteoblast differentiation in MSCs is therefore critical to promote the osteogenic potential of human MSCs. In this study, we used microarray analysis to identify signalling molecules that promote osteogenic differentiation in human bone marrow stroma derived MSCs. RESULTS Microarray analysis and validation experiments showed that the expression of IGF2 and IGFBP2 was increased together with integrin alpha5 (ITGA5) during dexamethasone-induced osteoblast differentiation in human MSCs. This effect was functional since we found that IGF2 and IGFBP2 enhanced the expression of osteoblast phenotypic markers and in vitro osteogenic capacity of hMSCs. Interestingly, we showed that downregulation of endogenous ITGA5 using specific shRNA decreased IGF2 and IGFBP2 expression in hMSCs. Conversely, ITGA5 overexpression upregulated IGF2 and IGFBP2 expression in hMSCs, which indicates tight crosstalks between these molecules. Consistent with this concept, activation of endogenous ITGA5 using a specific antibody that primes the integrin, or a peptide that specifically activates ITGA5 increased IGF2 and IGFBP2 expression in hMSCs. Finally, we showed that pharmacological inhibition of FAK/ERK1/2-MAPKs or PI3K signalling pathways that are enhanced by ITGA5 activation, blunted IGF2 and IGFBP2 expression in hMSCs. CONCLUSION The results show that ITGA5 is a key mediator of IGF2 and IGFBP2 expression that promotes osteoblast differentiation in human MSCs, and reveal that crosstalks between ITGA5 and IGF2/IGFBP2 signalling are important mechanisms that trigger osteogenic differentiation in human bone marrow derived mesenchymal stromal cells.
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Affiliation(s)
- Zahia Hamidouche
- Laboratory of Osteoblast Biology and Pathology, INSERM U606, Paris F-75475, France
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Qiu Q, Yan X, Bell M, Di J, Tsang BK, Gruslin A. Mature IGF-II prevents the formation of "big" IGF-II/IGFBP-2 complex in the human circulation. Growth Horm IGF Res 2010; 20:110-117. [PMID: 19962924 DOI: 10.1016/j.ghir.2009.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 10/29/2009] [Accepted: 11/03/2009] [Indexed: 11/30/2022]
Abstract
IGF-II plays an important role in physiological and pathological processes involved in growth and metabolism. Despite the fact that "big" IGF-IIs, IGF-II(1-87) and IGF-II(1-104), have been identified in the circulation for decades in addition to "mature" IGF-II, the biological properties of these "big" IGF-IIs and the mechanisms regulating their bioavailability have not been fully elucidated. In this study we demonstrated that IGF-II (1-87), as an abundant "big" IGF-II form, exists at a molar ratio of 0.24 (CI 0.13-0.62) with respect to mature IGF-II in the normal human circulation. Mature and "big" IGF-II can equally form complexes with IGFBP-2 and IGFBP-3 in vitro, resulting in the inhibition of IGF-II's biological function. However, under physiological conditions which entails the presence of both "big" and mature IGF-II, "big" IGF-IIs preferably formed complexes with IGFBP-3 but not IGFBP-2, unlike mature IGF-II which was equally associated with both IGFBP-3 and IGFBP-2. "Big" IGF-II binding to IGFBP-2 was only evident when the "big"/mature IGF-II ratio approached 1 or higher. We concluded that mature IGF-II prevents the formation of "big" IGF-II/IGFBP-2 complex in the circulation of healthy human controls. This finding suggests the presence of previously unknown mechanisms in the regulation of IGF-II bioavailability. Elevation of the ratio of "big" to mature IGF-II in the circulation may result in altered bioavailability of "big" IGF-IIs. This mechanism is relevant in pathological conditions such as Non-Islet Cell Tumor-induced Hypoglycemia (NICTH) and Hepatitis C-associated Osteosclerosis (HCAO), in which "big" IGF-II(1-87) and IGF-II(1-104) are significantly elevated.
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Affiliation(s)
- Qing Qiu
- Chronic Disease Program, Ottawa Health Research Institute, Ottawa, Ontario, Canada
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Progressive osteosclerosis and visceral calcification after cord blood transplantation. Int J Hematol 2010; 91:542-5. [PMID: 20162469 DOI: 10.1007/s12185-010-0524-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 01/28/2010] [Accepted: 02/01/2010] [Indexed: 10/19/2022]
Abstract
A 26-year-old woman, who successfully underwent umbilical cord blood transplantation for aplastic anemia 4 years previously, had suffered from hepatosplenic microabscesses caused by unidentifiable grocott stain-positive spores from immediately after the transplantation. At 51 months post-transplant, we attempted bone marrow biopsy from her posterior iliac crest, but failed to penetrate the cortical bone. X-ray of her spine and pelvis showed marked and diffuse osteosclerosis. Retrospective analysis of computed tomography revealed the gradual replacement of sternal, vertebral, and pelvic bone marrow with calcified tissues in addition to the dispersed calcification of the liver, spleen, and kidneys over the last 2 years. The bone mineral density of the lumbar spine had increased but not that of the femoral neck. Biomedical parameters for bone remodeling demonstrated enhanced bone formation as well as bone resorption and secondary hyperparathyroidism. Based on the past reports, we suggest that chronic fungal infection, which caused visceral calcification, induced the production of humoral factors for osteoblastic activation.
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Yücel AE, Kart-Köseoglu H, Isiklar I, Kuruinci E, Ozdemir FN, Arslan H. Bone Mineral Density in Patients on Maintenance Hemodialysis and Effect of Chronic Hepatitis C Virus Infection. Ren Fail 2009; 26:159-64. [PMID: 15287200 DOI: 10.1081/jdi-120038501] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To determine the prevalence of osteopenia and osteoporosis in HD patients at our center; to investigate whether HCV infection affects BMD in hemodialysis patients; to test for correlations between bone mineral density (BMD) and clinical and laboratory parameters in this population. SUBJECTS AND METHODS The study involved 76 end-stage renal disease patients. Forty-three (56.6%) patients were tested negative for anti-HCV antibodies and HCV-RNA. Thirty-three (43.4%) of them had positivity of anti-HCV antibodies and permanent or intermittent HCV-RNA positivity at least for two years. Mean HD duration was 86.4 months. Patients completed a standard questionnaire that listed age, sex, occupation, education level; cause of renal failure, smoking history, dialysis duration, and sports activities engaged in during life, and pathologic bone fractures. The women answered additional items about age at menarche, number of pregnancies and menopausal status. Each subject underwent a baseline physical examination, including measurement of body weight and height for calculation of body mass index. The results of laboratory tests that had been done at monthly visits in the previous year were retrospectively evaluated, and mean levels for the year were used for correlation testing. Bone mineral density was measured in the spine, femoral neck and forearm. Relationships between BMD values and chronic HCV infection, laboratory results and clinical parameters were analyzed. RESULTS In the 43 patients who were negative for anti-HCV antibodies and HCV-RNA, spine BMD testing showed osteopenia in 16 (37.2%) cases and osteoporosis in 7 (16.3%) cases. The corresponding values for the neck of the femur were 14 (32.6%) and 6 (14.0%), and for the forearm were 19 (44.2%) and 15 (34.9%). In the 33 anti-HCV antibodies and HCV-RNA positive patients; spine BMD testing showed osteopenia in 10 (30.3%) cases and osteoporosis in 7 (21.2%) cases. The corresponding values for the neck of the femur were 17 (51.5%) and 4 (12.1%), and for the forearm were 4 (12.1%) and 25 (75.8%). Bone mineral density decreased as dialysis duration increased (p<0.05). There was no statistical difference between BMD measurements of chronic HCV infection positive and negative group. CONCLUSION However the mean BMD values for all three sites in the 76 HD patients were low HCV infection may not be a risk factor for low BMD in this population.
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Affiliation(s)
- A Eftal Yücel
- Division of Rheumatology, Faculty of Medicine, Baskent University, Ankara, Turkey.
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Liu YS, Lu Y, Liu W, Xie H, Luo XH, Wu XP, Yuan LQ, Liao EY. Connective tissue growth factor is a downstream mediator for preptin-induced proliferation and differentiation in human osteoblasts. Amino Acids 2009; 38:763-9. [DOI: 10.1007/s00726-009-0281-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 03/16/2009] [Indexed: 02/01/2023]
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Schwartz KM, Skinner JA. Hepatitis C-associated osteosclerosis: a case report. Skeletal Radiol 2008; 37:679-81. [PMID: 18414851 DOI: 10.1007/s00256-008-0471-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 01/14/2008] [Accepted: 01/21/2008] [Indexed: 02/02/2023]
Abstract
A 38-year-old man presented for evaluation of severe pain in his lower limbs of 16 months' duration. Radiographs showed diffuse bony sclerosis involving the axial and appendicular skeleton with marked cortical thickening in the diaphyseal regions of the long bones. Iliac crest biopsy revealed abundant sclerotic bone. The patient was diagnosed with hepatitis C secondary to intravenous drug use 20 years earlier, and the bony findings and clinical symptoms attributed to hepatitis C-associated osteosclerosis (HCAO). Little is known about the natural history of this disease; however, we discuss the patient's clinical course over 15 years.
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Affiliation(s)
- Kara M Schwartz
- Department of Radiology, 200 First Street SW, Rochester, MN 55905, USA
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Khosla S. Insulin-like growth factor binding protein-2: a novel regulator of skeletal gender differences? Endocrinology 2008; 149:2048-50. [PMID: 18427154 DOI: 10.1210/en.2008-0174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Sundeep Khosla
- Endocrine Research Unit, College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA.
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DeMambro VE, Clemmons DR, Horton LG, Bouxsein ML, Wood TL, Beamer WG, Canalis E, Rosen CJ. Gender-specific changes in bone turnover and skeletal architecture in igfbp-2-null mice. Endocrinology 2008; 149:2051-61. [PMID: 18276763 PMCID: PMC2329262 DOI: 10.1210/en.2007-1068] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
IGF-binding protein-2 (IGFBP-2) is a 36-kDa protein that binds to the IGFs with high affinity. To determine its role in bone turnover, we compared Igfbp2(-/-) mice with Igfbp2(+/+) colony controls. Igfbp2(-/-) males had shorter femurs and were heavier than controls but were not insulin resistant. Serum IGF-I levels in Igfbp2(-/-) mice were 10% higher than Igfbp2(+/+) controls at 8 wk of age; in males, this was accompanied by a 3-fold increase in hepatic Igfbp3 and Igfbp5 mRNA transcripts compared with Igfbp2(+/+) controls. The skeletal phenotype of the Igfbp2(-/-) mice was gender and compartment specific; Igfbp2(-/-) females had increased cortical thickness with a greater periosteal circumference compared with controls, whereas male Igfbp2(-/-) males had reduced cortical bone area and a 20% reduction in the trabecular bone volume fraction due to thinner trabeculae than Igfbp2(+/+) controls. Serum osteocalcin levels were reduced by nearly 40% in Igfbp2(-/-) males, and in vitro, both CFU-ALP(+) preosteoblasts, and tartrate-resistant acid phosphatase-positive osteoclasts were significantly less abundant than in Igfbp2(+/+) male mice. Histomorphometry confirmed fewer osteoblasts and osteoclasts per bone perimeter and reduced bone formation in the Igfbp2(-/-) males. Lysates from both osteoblasts and osteoclasts in the Igfbp2(-/-) males had phosphatase and tensin homolog (PTEN) levels that were significantly higher than Igfbp2(+/+) controls and were suppressed by addition of exogenous IGFBP-2. In summary, there are gender- and compartment-specific changes in Igfbp2(-/-) mice. IGFBP-2 may regulate bone turnover in both an IGF-I-dependent and -independent manner.
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Affiliation(s)
- V E DeMambro
- The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA.
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Simonelli C, Adler RA, Blake GM, Caudill JP, Khan A, Leib E, Maricic M, Prior JC, Eis SR, Rosen C, Kendler DL. Dual-Energy X-Ray Absorptiometry Technical Issues: The 2007 ISCD Official Positions. J Clin Densitom 2008; 11:109-22. [PMID: 18442756 DOI: 10.1016/j.jocd.2007.12.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 12/05/2007] [Indexed: 02/06/2023]
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Abstract
Insulin-like growth factor-binding proteins (IGFBPs) are important regulators of bone metabolism. However, their precise roles are not fully understood, since IGFBPs can have both enhancing and inhibiting effects on IGF action, depending on context and posttranslational modifications, as well as IGF-independent effects. This review focuses on recent findings from cell culture, rodent models, and clinical studies concerning local IGFBP-2, IGFBP-4, and IGFBP-5 action in bone.
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Affiliation(s)
- Cheryl A Conover
- Endocrine Research Unit, Division of Endocrinology and Metabolosm, Department of Medicine, Mayo Clinic, 200 First St. SW, 5-194 Joseph, Rochester, MN 55905, USA.
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Viereck V, Siggelkow H, Pannem R, Braulke T, Scharf JG, Kübler B. Alteration of the insulin-like growth factor axis during in vitro differentiation of the human osteosarcoma cell line HOS 58. J Cell Biochem 2007; 102:28-40. [PMID: 17372931 DOI: 10.1002/jcb.21274] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The insulin-like growth factors I and II (IGF-I, IGF-II), their receptors, and high affinity binding proteins (IGFBPs) represent a family of cellular modulators that play essential roles in the development and differentiation of cells and tissues including the skeleton. Recently, the human osteosarcoma cell line HOS 58 cells were used as an in vitro model of osteoblast differentiation characterized by (i) a rapid proliferation rate in low-density cells that decreased continuously with time of culture and (ii) an increasing secretion of matrix proteins during their in vitro differentiation. In the present paper, HOS 58 cells with low cell density at early time points of the in vitro differentiation (i) displayed a low expression of IGF-I and -II; (ii) synthesized low levels of IGFBP-2, -3, -4, and -5, but (iii) showed high expression levels of both the type I and II IGF receptors. During the in vitro differentiation of HOS 58 cells, IGF-I and -II expressions increased continuously in parallel with an upregulation of IGFBP-2, -3, -4, and -5 whereas the IGF-I receptor and IGF-II/M6P receptor mRNA were downregulated. In conclusion, the high proliferative activity in low cell density HOS 58 cells was associated with high mRNA levels of the IGF-IR, but low concentrations of IGFBP-2. The rate of proliferation of HOS 58 cells continuously decreased during cultivation in parallel with a decline in IGF-IR expression, but increase of mitoinhibitory IGFBP-2. These data are indicative for a role of the IGF axis during the in vitro differentiation of HOS 58 cells.
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Affiliation(s)
- Volker Viereck
- Department of Obstetrics and Gynecology, Georg-August-Universität, Göttingen, Germany
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Abstract
Osteoporotic fractures are an important public health problem, contributing substantially to morbidity and mortality in an ageing world population and consuming considerable health resources. Presently available pharmacologic therapies for prevention of fragility fractures are limited in scope, efficacy and acceptability to patients. Considerable efforts are being made to develop new, more effective treatments for osteoporosis, and to refine/optimize existing therapies. These novel treatments include an expanding array of drugs that primarily inhibit osteoclastic bone resorption: estrogenic compounds, bisphosphonates, inhibitors of receptor activator of NF-kappaB ligand signaling, cathepsin K inhibitors, c-src kinase inhibitors, integrin inhibitors and chloride channel inhibitors. The advent of intermittent parathyroid hormone (PTH) therapy has provided proof-of-principle that osteoblast-targeted (anabolic) agents can effectively prevent osteoporotic fractures, and is likely to be followed by the introduction of other therapies based on PTH (orally active PTH analogs, antagonists of the calcium sensing receptor, PTH-related peptide analogs) and/or agents that induce osteoblast anabolism by means of pathways involving key, recently identified, molecular targets (wnt-low-density lipoprotein receptor-related protein 5 signaling, sclerostin and matrix extracellular phosphoglycoprotein).
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Affiliation(s)
- Andrew Grey
- University of Auckland, Department of Medicine, Auckland, New Zealand.
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Amin S, Riggs BL, Melton LJ, Achenbach SJ, Atkinson EJ, Khosla S. High serum IGFBP-2 is predictive of increased bone turnover in aging men and women. J Bone Miner Res 2007; 22:799-807. [PMID: 17352648 DOI: 10.1359/jbmr.070306] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Elevated serum IGFBP-2 is associated with lower BMD in men and women. It is unknown whether IGFBP-2 serves as a negative regulator of bone metabolism by decreasing bone formation or increasing bone resorption. Studying an age-stratified community-based sample of 344 men and 276 women, IGFBP-2 was the strongest predictor of increased bone resorption among the IGF/IGFBPs studied. INTRODUCTION Serum insulin-like growth factor binding protein-2 (IGFBP-2), which increases with age, is a predictor of low BMD among aging men and women. However, it is unknown whether IGFBP-2 negatively influences bone metabolism by decreasing bone formation or increasing bone resorption. Few have examined the relation between the insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) with bone turnover markers. MATERIALS AND METHODS In an age-stratified, random sample of the community, we examined the association between serum IGF-I, IGF-II, IGFBP-1, -2, and -3, and bone turnover markers before and after adjustment for potential confounders (age, body mass index, bioavailable estradiol and testosterone, and sex hormone binding globulin). Analyses were stratified by sex and menopausal status. RESULTS We studied 344 men (age range, 23-90 yr) and 276 women (age range, 21-93 yr; 166 postmenopausal) not on oral contraceptives or hormone replacement. Among the IGF/IGFBPs assessed, IGFBP-2 was the strongest and most consistent predictor of bone turnover in men and women. After adjustment for potential confounders, IGFBP-2 was positively associated with osteocalcin (OC) and urine and serum N-teleopeptide (NTX) in men (r = 0.20, 0.26, and 0.23, respectively; p < 0.001), serum C-telopeptide (CTX) in premenopausal women (r = 0.28; p < 0.01), and OC, urine NTX, and serum CTX in postmenopausal women (r = 0.24, 0.33, and 0.19, respectively; p < 0.05). CONCLUSIONS Higher serum IGFBP-2, which is predictive of lower BMD, is associated with increased markers of bone resorption, independent of age, body mass, and sex hormones. The association between IGFBP-2 and markers of bone formation may reflect coupling with increased bone resorption, which is not adequate to maintain BMD.
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Affiliation(s)
- Shreyasee Amin
- Division of Rheumatology, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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Hoeflich A, Götz W, Lichanska AM, Bielohuby M, Tönshoff B, Kiepe D. Effects of insulin-like growth factor binding proteins in bone -- a matter of cell and site. Arch Physiol Biochem 2007; 113:142-53. [PMID: 17922310 DOI: 10.1080/13813450701531193] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The actions of the insulin-like growth factor (IGF)-system are controlled by six IGF-binding proteins (IGFBPs). The IGFBPs are thought to affect local effects of IGF-I and IGF-II due to higher affinity if compared to IGF-I receptors and due to cell-type specific IGFBP expression patterns. It was found in IGFBP knockout models that the IGFBP family is functionally redundant. Thus, functional analysis of potential effects of IGFBPs is dependent on descriptive studies and models of IGFBP overexposure in vitro and in vivo. In the literature, the role of the IGFBPs for bone growth is highly controversial and, to date, no systematic look has been taken at IGFBPs resolving functional aspects of IGFBPs at levels of cell types and specific locations within bones. Since IGFBPs are thought to represent local modulators of the IGF actions and also exert IGF-independent effects, this approach is particularly reasonable on a physiological level. By sorting the huge number of in part controversial results on IGFBP effects in bone present in the literature for distinct cell types and bone sites it is possible to generate a focused, more specific and a less controversial picture of IGFBP functions in bone.
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Affiliation(s)
- A Hoeflich
- Laboratory of Mouse Genetics, Research Unit of Genetics and Biometry, Research Institute for the Biology of Farm Animals Dummerstorf (FBN), Germany.
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Miyamoto S, Nakamura M, Yano K, Ishii G, Hasebe T, Endoh Y, Sangai T, Maeda H, Shi-Chuang Z, Chiba T, Ochiai A. Matrix metalloproteinase-7 triggers the matricrine action of insulin-like growth factor-II via proteinase activity on insulin-like growth factor binding protein 2 in the extracellular matrix. Cancer Sci 2007; 98:685-91. [PMID: 17359288 PMCID: PMC11158237 DOI: 10.1111/j.1349-7006.2007.00448.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Many growth factors and cytokines are immobilized on the extracellular matrix (ECM) by binding to glycosaminoglycans and are stored in an inactive form in the cellular microenvironment. However, the mechanisms of ECM-bound growth factor or cytokine activation have not been well documented. We showed that the insulin-like growth factor type-1 receptor (IGF-1R) was rapidly phosphorylated after the addition of matrix metalloproteinase (MMP)-7 to a serum-starved human colon cancer cell line (HT29) and that phosphorylation was completely inhibited by an IGF-II neutralizing antibody. In the ECM of this cell line, IGF-II and IGF binding protein (BP)-2 coexisted, but IGFBP-2 disappeared from the ECM fraction after treatment with MMP-7 or heparinase III. On the other hand, in a cell line in which IGF-1R was overexpressed, IGF-1R was phosphorylated by supernatant from the MMP-7-treated ECM fraction of HT29 but not by that from a heparinase-III-treated ECM fraction. We also demonstrated that MMP-7 degrades IGFBP-2 in vitro at three cleavage sites (peptide bonds E(151)-L(152), G(175)-L(176) and K(181)-L(182)), which have not been documented previously. Taken together, these results demonstrate that MMP-7 generates bioactive IGF-II by degrading the IGF-II/IGFBP-2 complex binding to heparan sulfate proteoglycan in the ECM, resulting in IGF-II-induced signal transduction. This evidence indicates that some ECM-associated growth factors enhance their ability to bind to their receptors by some proteases in the tumor microenvironment. This mechanism of action ('protease-triggered matricrine') represents an attractive model for understanding ECM-tumor interactions.
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Affiliation(s)
- Shin'ichi Miyamoto
- Pathology Division, National Cancer Center Research Institute East, Chiba 277-8577, Japan
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Cornish J, Callon KE, Bava U, Watson M, Xu X, Lin JM, Chan VA, Grey AB, Naot D, Buchanan CM, Cooper GJS, Reid IR. Preptin, another peptide product of the pancreatic beta-cell, is osteogenic in vitro and in vivo. Am J Physiol Endocrinol Metab 2007; 292:E117-22. [PMID: 16912056 DOI: 10.1152/ajpendo.00642.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several hormones that regulate nutritional status also impact on bone metabolism. Preptin is a recently isolated 34-amino acid peptide hormone that is cosecreted with insulin and amylin from the pancreatic beta-cells. Preptin corresponds to Asp(69)-Leu(102) of pro-IGF-II. Increased circulating levels of a pro-IGF-II peptide complexed with IGF-binding protein-2 have been implicated in the high bone mass phenotype observed in patients with chronic hepatitis C infection. We have assessed preptin's activities on bone. Preptin dose-dependently stimulated the proliferation (cell number and DNA synthesis) of primary fetal rat osteoblasts and osteoblast-like cell lines at periphysiological concentrations (>10(-11) M). In addition, thymidine incorporation was stimulated in murine neonatal calvarial organ culture, likely reflecting the proliferation of cells from the osteoblast lineage. Preptin did not affect bone resorption in this model. Preptin induced phosphorylation of p42/p44 MAP kinases in osteoblastic cells in a dose-dependent manner (10(-8)-10(-10) M), and its proliferative effects on primary osteoblasts were blocked by MAP kinase kinase inhibitors. Preptin also reduced osteoblast apoptosis induced by serum deprivation, reducing the number of apoptotic cells by >20%. In vivo administration of preptin increased bone area and mineralizing surface in adult mice. These data demonstrate that preptin, which is cosecreted from the pancreatic beta-cell with amylin and insulin, is anabolic to bone and may contribute to the preservation of bone mass observed in hyperinsulinemic states such as obesity.
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Affiliation(s)
- J Cornish
- Dept. of Medicine, Univ. of Auckland, Private Bag 92019, Auckland, NZ, USA.
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Street ME, Spaggiari C, Ziveri MA, Volta C, Federico G, Baroncelli GI, Bernasconi S, Saggese G. Analysis of bone mineral density and turnover in patients with cystic fibrosis: associations between the IGF system and inflammatory cytokines. HORMONE RESEARCH 2006; 66:162-8. [PMID: 16804317 DOI: 10.1159/000094143] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 05/15/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) patients present an increased risk of osteoporosis, and increased fracture rate. Several factors have been identified as modulators of bone metabolism and bone mineral density (BMD). AIMS To evaluate BMD and serum markers of bone turnover and establish their relationships with serum concentrations of interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF)-alpha, IGF-I, IGF-II, IGF binding protein (IGFBP)-2, IGFBP-3, and parathyroid hormone (PTH) in young adult CF patients. METHODS Seventeen young adult CF patients (4 M, 13 F; mean age: 26.6 +/- 1.1 years) were enrolled in the study and analysed as a whole and as two subgroups according to the Shwachman-Kulczycki score. BMD was assessed at the lumbar spine (L1-L4) by dual energy X-ray absorptiometry (DXA Hologic QDR 2000). Bone turnover was assessed by measuring serum levels of osteocalcin (OC) and serum carboxyterminal propeptide of type I collagen (PICP) as markers of bone formation, and serum cross-linked carboxyterminal telopeptide of type I collagen (ICTP) as a marker of bone resorption. Serum IGFs, IGFBPs, and cytokines were assayed using special commercial kits. Daily calcium intake and weekly physical activity were estimated by questionnaires. Forced expiratory volume in one second was used to assess pulmonary function. RESULTS Lumbar BMD was normal, although there was a tendency to be lower in the patients with a lower clinical score. Both OC and PICP were increased, whereas ICTP was normal. Lumbar BMD was positively correlated with pulmonary function. IL-6 and C-reactive protein (markers of inflammation) were inversely correlated with PICP. Serum ICTP levels were correlated with serum IGF-I levels. No significant relationship was detected among lumbar BMD, markers of bone turnover and PTH, IGF-I, IGF-II, IGFBP-2, IGFBP-3, TNF-alpha, IL-1beta, and body mass index Z-score. CONCLUSIONS Bone turnover is abnormal in CF patients. Young adult CF patients with satisfying clinical status and nutritional conditions have normal BMD and increased serum OC and PICP levels.
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Affiliation(s)
- Maria E Street
- Department of Pediatrics, University of Parma, Parma, Italy.
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