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Kondo H, Kondo M, Hayashi K, Kusafuka S, Hamamura K, Tanaka K, Kodama D, Hirai T, Sato T, Ariji Y, Miyazawa K, Ariji E, Goto S, Togari A. Orthodontic tooth movement-activated sensory neurons contribute to enhancing osteoclast activity and tooth movement through sympathetic nervous signalling. Eur J Orthod 2021; 44:404-411. [PMID: 34642757 DOI: 10.1093/ejo/cjab072] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Orthodontic tooth movement (OTM) increases sympathetic and sensory neurological markers in periodontal tissue. However, the relationship between the sympathetic and sensory nervous systems during OTM remains unclear. Therefore, the present study investigated the relationship between the sympathetic and sensory nervous systems activated by OTM using pharmacological methods. MATERIALS AND METHODS We compared the effects of sympathectomy and sensory nerve injury during OTM in C57BL6/J mice. Capsaicin (CAP) was used to induce sensory nerve injury. Sympathectomy was performed using 6-hydroxydopamine. To investigate the effects of a β-agonist on sensory nerve injury, isoproterenol (ISO) was administered to CAP-treated mice. Furthermore, to examine the role of the central nervous system in OTM, the ventromedial hypothalamic nucleus (VMH) was ablated using gold thioglucose. RESULTS Sensory nerve injury and sympathectomy both suppressed OTM and decreased the percent of the alveolar socket covered with osteoclasts (Oc.S/AS) in periodontal tissue. Sensory nerve injury inhibited increases in OTM-induced calcitonin gene-related peptide (CGRP) immunoreactivity (IR), a marker of sensory neurons, and tyrosine hydroxylase (TH) IR, a marker of sympathetic neurons, in periodontal tissue. Although sympathectomy did not decrease the number of CGRP-IR neurons in periodontal tissue, OTM-induced increases in the number of TH-IR neurons were suppressed. The ISO treatment restored sensory nerve injury-inhibited tooth movement and Oc.S/AS. Furthermore, the ablation of VMH, the centre of the sympathetic nervous system, suppressed OTM-induced increases in tooth movement and Oc.S/AS. CONCLUSIONS The present results suggest that OTM-activated sensory neurons contribute to enhancements in osteoclast activity and tooth movement through sympathetic nervous signalling.
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Affiliation(s)
- Hisataka Kondo
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Mayo Kondo
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.,Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Kaori Hayashi
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.,Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Sae Kusafuka
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.,Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Kazunori Hamamura
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Kenjiro Tanaka
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Daisuke Kodama
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Takao Hirai
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Takuma Sato
- Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Yoshiko Ariji
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Ken Miyazawa
- Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Eiichiro Ariji
- Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Shigemi Goto
- Department of Orthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
| | - Akifumi Togari
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
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2
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Tomomura A, Bandow K, Tomomura M. Purification and Biological Function of Caldecrin. Medicines (Basel) 2021; 8:medicines8080041. [PMID: 34436220 PMCID: PMC8398347 DOI: 10.3390/medicines8080041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Blood calcium homeostasis is critical for biological function. Caldecrin, or chymotrypsin-like elastase, was originally identified in the pancreas as a serum calcium-decreasing factor. The serum calcium-decreasing activity of caldecrin requires the trypsin-mediated activation of the protein. Protease activity-deficient mature caldecrin can also reduce serum calcium concentration, indicating that structural processing is necessary for serum calcium-decreasing activity. Caldecrin suppresses the differentiation of bone-resorbing osteoclasts from bone marrow macrophages (BMMs) by inhibiting receptor activator of NF-κB ligand (RANKL)-induced nuclear factor of activated T-cell cytoplasmic 1 expression via the Syk-PLCγ-Ca2+ oscillation-calcineurin signaling pathway. It also suppresses mature osteoclastic bone resorption by RANKL-stimulated TRAF6-c-Src-Syk-calcium entry and actin ring formation. Caldecrin inhibits lipopolysaccharide (LPS)-induced osteoclast formation in RANKL-primed BMMs by inducing the NF-κB negative regulator A20. In addition, caldecrin suppresses LPS-mediated M1 macrophage polarization through the immunoreceptor triggering receptor expressed on myeloid cells (TREM) 2, suggesting that caldecrin may function as an anti-osteoclastogenic and anti-inflammatory factor via TREM2. The ectopic intramuscular expression of caldecrin cDNA prevents bone resorption in ovariectomized mice, and the administration of caldecrin protein also prevents skeletal muscle destruction in dystrophic mice. In vivo and in vitro studies have indicated that caldecrin is a unique multifunctional protease and a possible therapeutic target for skeletal and inflammatory diseases.
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Affiliation(s)
- Akito Tomomura
- Division of Biochemistry, Department of Oral Biology & Tissue Engineering, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama 350-0283, Japan;
| | - Kenjiro Bandow
- Division of Biochemistry, Department of Oral Biology & Tissue Engineering, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama 350-0283, Japan;
| | - Mineko Tomomura
- Department of Oral Health Sciences, Meikai University School of Health Sciences, 1-1 Akemi, Urayasu, Chiba 279-8550, Japan;
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3
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Wang L, Hou S, Sabsovich I, Guo TZ, Wei T, Kingery WS. Mice lacking substance P have normal bone modeling but diminished bone formation, increased resorption, and accelerated osteopenia with aging. Bone 2021; 144:115806. [PMID: 33333245 PMCID: PMC7856000 DOI: 10.1016/j.bone.2020.115806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/17/2022]
Abstract
Substance P (SP) is a sensory neuropeptide that is expressed by the neurons innervating bone. There is considerable evidence that SP can regulate bone cell function in vitro, but it is unclear whether SP modulates bone modeling or remodeling in vivo. To answer this question we characterized the bone phenotype of mice with deletion of the Tac1 gene expressing SP. The phenotypes of 2-month-old and 5-month-old SP deficient mice and their wildtype controls were characterized by using μCT imaging, static and dynamic bone histomorphometry, and urinary deoxypyridinoline cross-links (DPD) measurement. No differences in bone phenotypes were observed between the 2 strains at 2 months of age. By 5 months both the wildtype and SP deficient mice had developed cancellous osteopenia, but relative to the wild-type mice the SP deficient mice had significantly greater cancellous bone loss. The SP deficient mice also exhibited decreased bone formation, increased osteoclast number, and increased urinary DPD levels. Cortical defect early repair was delayed in 5-month-old mice lacking SP. Collectively, these findings indicate that SP signaling is not required for bone modeling, but SP signaling reduces age-related osteopenia and accelerates cortical defect reparation, data supporting the hypothesis that SP is an anabolic physiologic regulator of bone metabolism.
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Affiliation(s)
- Liping Wang
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America.
| | - Saiyun Hou
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Ilya Sabsovich
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America.
| | - Tian-Zhi Guo
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Tzuping Wei
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Wade S Kingery
- Palo Alto Veterans Institute for Research, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, United States of America.
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4
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Xie J, Guo J, Kanwal Z, Wu M, Lv X, Ibrahim NA, Li P, Buabeid MA, Arafa ESA, Sun Q. Calcitonin and Bone Physiology: In Vitro, In Vivo, and Clinical Investigations. Int J Endocrinol 2020; 2020:3236828. [PMID: 32963524 PMCID: PMC7501564 DOI: 10.1155/2020/3236828] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/18/2020] [Accepted: 08/27/2020] [Indexed: 12/15/2022] Open
Abstract
Calcitonin was discovered as a peptide hormone that was known to reduce the calcium levels in the systemic circulation. This hypocalcemic effect is produced due to multiple reasons such as inhibition of bone resorption or suppression of calcium release from the bone. Thus, calcitonin was said as a primary regulator of the bone resorption process. This is the reason why calcitonin has been used widely in clinics for the treatment of bone disorders such as osteoporosis, hypercalcemia, and Paget's disease. However, presently calcitonin usage is declined due to the development of efficacious formulations of new drugs. Calcitonin gene-related peptides and several other peptides such as intermedin, amylin, and adrenomedullin (ADM) are categorized in calcitonin family. These peptides are known for the structural similarity with calcitonin. Aside from having a similar structure, these peptides have few overlapping biological activities and signal transduction action through related receptors. However, several other activities are also present that are peptide specific. In vitro and in vivo studies documented the posttreatment effects of calcitonin peptides, i.e., positive effect on bone osteoblasts and their formation and negative effect on osteoclasts and their resorption. The recent research studies carried out on genetically modified mice showed the inhibition of osteoclast activity by amylin, while astonishingly calcitonin plays its role by suppressing osteoblast and bone turnover. This article describes the review of the bone, the activity of the calcitonin family of peptides, and the link between them.
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Affiliation(s)
- Jingbo Xie
- Department of Orthopedics, Fengcheng People's Hospital, Fengcheng, Jiangxi 331100, China
| | - Jian Guo
- Department of the Second Orthopedics, Hongdu Hospital of Traditional Chinese Medicine Affiliated to Jiangxi University of Traditional Chinese Medicine, Nanchang Hongdu Traditional Chinese Medicine Hospital, Nanchang, Jiangxi 330008, China
| | | | - Mingzheng Wu
- Department of Orthopaedics, Pu'ai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430000, China
| | - Xiangyang Lv
- Department of Orthopaedics, Xi'an International Medical Center Hospital, Xi'an, Shaanxi 710100, China
| | | | - Ping Li
- Department of Orthopaedics, Ya'an People's Hospital, Ya'an, Sichuan 625000, China
| | | | | | - Qingshan Sun
- Department of Orthopedics, The Third Hospital of Shandong Province, Jinan, Shandong 250031, China
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5
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Abstract
Alpha-calcitonin gene-related peptide (αCGRP) plays a significant pathophysiological role in the regulation of bone metabolism. Our previous research indicated that αCGRP might have a potential application in enhancing osseointegration in vivo. To further uncover the intrinsic mechanism of its networks in bone regeneration, here we investigate the impact of αCGRP on osteogenic differentiation in bone marrow-derived mesenchymal stem cells (BMSCs) from both wild-type and αCGRP-/- mice. Considering the half-life of αCGRP in plasma is only 10 min, we applied αCGRP lentivirus and stably transfected it into BMSCs, followed by transfection identification and cell cycle assay. We further conducted a series of in vitro tests, and the results revealed that biological functions including migratory ability and osteogenicity exhibited positive correlation with BMSCs' αCGRP expression. Meanwhile, this phenomenon was associated with an enhanced expression of YAP (Yes-associated protein), the key downstream effector of the Hippo pathway. To sum up, our data together with previous in vivo observations is likely to elucidate the intrinsic mechanism of αCGRP in bone remodeling, and αCGRP would appear to be a novel treatment to promote bone wound healing.
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Affiliation(s)
- Bin Wang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Both the authors contributed equally to this article
| | - Jie Lin
- Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Both the authors contributed equally to this article
| | - Qin Zhang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Xinyuan Zhang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Hui Yu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Ping Gong
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Lin Xiang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.,Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
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6
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Abstract
Calcitonin was discovered over 50 yr ago as a new hormone that rapidly lowers circulating calcium levels. This effect is caused by the inhibition of calcium efflux from bone, as calcitonin is a potent inhibitor of bone resorption. Calcitonin has been in clinical use for conditions of accelerated bone turnover, including Paget's disease and osteoporosis; although in recent years, with the development of drugs that are more potent inhibitors of bone resorption, its use has declined. A number of peptides that are structurally similar to calcitonin form the calcitonin family, which currently includes calcitonin gene-related peptides (αCGRP and βCGRP), amylin, adrenomedullin, and intermedin. Apart from being structurally similar, the peptides signal through related receptors and have some overlapping biological activities, although other activities are peptide specific. In bone, in vitro studies and administration of the peptides to animals generally found inhibitory effects on osteoclasts and bone resorption and positive effects on osteoblasts and bone formation. Surprisingly, studies in genetically modified mice have demonstrated that the physiological role of calcitonin appears to be the inhibition of osteoblast activity and bone turnover, whereas amylin inhibits osteoclast activity. The review article focuses on the activities of peptides of the calcitonin family in bone and the challenges in understanding the relationship between the pharmacological effects and the physiological roles of these peptides.
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Affiliation(s)
- Dorit Naot
- Department of Medicine, University of Auckland , Auckland , New Zealand
| | - David S Musson
- Department of Medicine, University of Auckland , Auckland , New Zealand
| | - Jillian Cornish
- Department of Medicine, University of Auckland , Auckland , New Zealand
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7
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Jeevaratnam K, Salvage SC, Li M, Huang CLH. Regulatory actions of 3',5'-cyclic adenosine monophosphate on osteoclast function: possible roles of Epac-mediated signaling. Ann N Y Acad Sci 2018; 1433:18-28. [PMID: 29846007 DOI: 10.1111/nyas.13861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/20/2018] [Accepted: 04/26/2018] [Indexed: 02/02/2023]
Abstract
Alterations in cellular levels of the second messenger 3',5'-cyclic adenosine monophosphate ([cAMP]i ) regulate a wide range of physiologically important cellular signaling processes in numerous cell types. Osteoclasts are terminally differentiated, multinucleated cells specialized for bone resorption. Their systemic regulator, calcitonin, triggers morphometrically and pharmacologically distinct retraction (R) and quiescence (Q) effects on cell-spread area and protrusion-retraction motility, respectively, paralleling its inhibition of bone resorption. Q effects were reproduced by cholera toxin-mediated Gs -protein activation known to increase [cAMP]i , unaccompanied by the [Ca2+ ]i changes contrastingly associated with R effects. We explore a hypothesis implicating cAMP signaling involving guanine nucleotide-exchange activation of the small GTPase Ras-proximate-1 (Rap1) by exchange proteins directly activated by cAMP (Epac). Rap1 activates integrin clustering, cell adhesion to bone matrix, associated cytoskeletal modifications and signaling processes, and transmembrane transduction functions. Epac activation enhanced, whereas Epac inhibition or shRNA-mediated knockdown compromised, the appearance of markers for osteoclast differentiation and motility following stimulation by receptor activator of nuclear factor kappa-Β ligand (RANKL). Deficiencies in talin and Rap1 compromised in vivo bone resorption, producing osteopetrotic phenotypes in genetically modified murine models. Translational implications of an Epac-Rap1 signaling hypothesis in relationship to N-bisphosphonate actions on prenylation and membrane localization of small GTPases are discussed.
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Affiliation(s)
- Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.,School of Medicine, Perdana University - Royal College of Surgeons Ireland, Selangor, Malaysia
| | - Samantha C Salvage
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Mengye Li
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Christopher L-H Huang
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,Physiological Laboratory, University of Cambridge, Cambridge, UK
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Suzuki H, Yamamoto T. Localization of amylin-like immunoreactivity in the striped velvet gecko pancreas. Anat Histol Embryol 2018; 47:159-166. [PMID: 29315753 DOI: 10.1111/ahe.12337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/22/2017] [Indexed: 12/23/2022]
Abstract
Immunohistochemical techniques were employed to investigate the distribution of amylin-like immunoreactive cells in the pancreas of gecko Homopholis fasciata. Four types of endocrine cells were distinguished: insulin immunoreactive (B cells), pancreatic polypeptide immunoreactive (PP cells), glucagon and pancreatic polypeptide immunoreactive (A/PP cells) and somatostatin immunoreactive cells (D cells). Pancreatic islets contained B, A/PP and D cells, whereas extrainsular regions contained B, D and PP cells. In the pancreatic islets, amylin-like immunoreactive cells corresponded to B cells, but not to A/PP or D cells. In the extrainsular regions, amylin-like immunoreactive cells corresponded to either B or PP cells. Amylin secreted from intrainsular B cells may regulate pancreatic hormone secretion in an autocrine and/or a paracrine fashion. On the other hand, amylin secreted from extrainsular PP and B cells, and/or intrainsular B cells may participate in the modulation of calcium homoeostasis in an endocrine fashion.
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Affiliation(s)
- H Suzuki
- Brain Functions and Neuroscience Unit, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan.,Department of Biology, University of Teacher Education Fukuoka, Munakata, Fukuoka, Japan
| | - T Yamamoto
- Brain Functions and Neuroscience Unit, Department of Oral Science, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
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Abstract
PURPOSE OF REVIEW This study is to highlight recent discoveries associated with the role of calcitonin peptide family and their receptors in prostate cancer progression and bone metastasis. RECENT FINDINGS Studies have linked adrenomedullin (AM), calcitonin (CT) and calcitonin gene-related peptide (CGRP) to the spread of prostate tumours to the bone. AM can induce a metastatic phenotype in prostate cancer cells through its action on TRPV2 calcium channels and is also capable of influencing localised levels of RANKL in the bone to favour tumourigenesis. CT utilises A-kinase anchoring proteins to indirectly act on PKA and promote metastasis in prostate cancer. The receptor for CT contains a PDZ-binding domain, the deletion of which stops metastasis to the bone in orthotopic prostate models. SUMMARY Recent findings show strong evidence for the role of calcitonin peptides and receptors in prostate cancer and bone metastasis. Further research could provide potential prognostic markers and therapeutic targets for prostate cancer patients.
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Mabilleau G, Perrot R, Mieczkowska A, Boni S, Flatt PR, Irwin N, Chappard D. Glucose-dependent insulinotropic polypeptide (GIP) dose-dependently reduces osteoclast differentiation and resorption. Bone 2016; 91:102-12. [PMID: 27451082 DOI: 10.1016/j.bone.2016.07.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/23/2016] [Accepted: 07/18/2016] [Indexed: 12/13/2022]
Abstract
A role for glucose-dependent insulinotropic polypeptide (GIP) in controlling bone resorption has been suspected. However uncertainty remains to identify whether GIP act directly on osteoclasts. The aim of the present study were (i) to identify in different osteoclast differentiation models (human peripheral blood mononuclear cells-PBMC, murine bone marrow macrophage-BMM and murine Raw 264.7 cells) whether GIP was capable of reducing osteoclast formation and resorption; (ii) ascertain whether the highly potent GIP analogue N-AcGIP was capable of inducing a response at lower concentrations and (iii) to decipher the molecular mechanisms responsible for such effects. [d-Ala(2)]-GIP dose-dependently reduced osteoclast formation at concentration as low as 1nM in human PBMC and 10nM in murine BMM cultures. Furthermore, [d-Ala(2)]-GIP also reduced the extent of osteoclast resorption at concentration as low as 1nM in human PBMC and murine BMM cultures. The mechanism of action of [d-Ala(2)]-GIP appeared to be mediated by reduction in intracellular calcium concentration and oscillation that subsequently inhibited calcineurin activity and NFATc1 nuclear translocation. The potency of the highly potent N-AcGIP was determined and highlighted an effect on osteoclast formation and resorption at concentration ten times lower than observed with [d-Ala(2)]-GIP in vitro. Furthermore, N-AcGIP was also capable of reducing the number of osteoclast in ovariectomized mice as well as the circulating level of type I collagen C-telopeptide. Pharmacological concentrations required for reducing osteoclast formation and resorption provide the impetus to design and exploit enzymatically stable GIP analogues for the treatment of bone resorption disorders in humans.
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Affiliation(s)
- Guillaume Mabilleau
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France; SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France.
| | - Rodolphe Perrot
- SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France
| | - Aleksandra Mieczkowska
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France
| | - Sébastien Boni
- Lentivec, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Diabetes Research Group, Biomedical Sciences Research Institute, University of Ulster, BT52 1SA Coleraine, United Kingdom
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Diabetes Research Group, Biomedical Sciences Research Institute, University of Ulster, BT52 1SA Coleraine, United Kingdom
| | - Daniel Chappard
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux - LHEA, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France; SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, University of Angers, 49933 ANGERS Cedex, France
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11
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Amso Z, Cornish J, Brimble MA. Short Anabolic Peptides for Bone Growth. Med Res Rev 2016; 36:579-640. [DOI: 10.1002/med.21388] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/24/2016] [Accepted: 02/15/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Zaid Amso
- School of Chemical Sciences; The University of Auckland, 23 Symonds St; Auckland 1142 New Zealand
| | - Jillian Cornish
- Department of Medicine; The University of Auckland; Auckland 1010 New Zealand
| | - Margaret A. Brimble
- School of Chemical Sciences; The University of Auckland, 23 Symonds St; Auckland 1142 New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences; The University of Auckland; Auckland 1142 New Zealand
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12
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Tomomura M, Tomomura A. Caldecrin: A pancreas-derived hypocalcemic factor, regulates osteoclast formation and function. World J Biol Chem 2015; 6:358-365. [PMID: 26629319 PMCID: PMC4656912 DOI: 10.4331/wjbc.v6.i4.358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/31/2015] [Accepted: 09/30/2015] [Indexed: 02/05/2023] Open
Abstract
Caldecrin was originally isolated from the pancreas as a factor that reduced serum calcium levels. This secreted serine protease has chymotrypsin-like activity and is also known as chymotrypsin C; it belongs to the elastase family. Although intravenous administration of caldecrin decreases the serum calcium concentration even when its protease activity is blocked, this effect does require cleavage of caldecrin’s pro-peptide by trypsin, converting it to the mature enzyme. Ectopic intramuscular expression of caldecrin prevented bone resorption in ovariectomized mice. Caldecrin inhibited parathyroid hormone-stimulated calcium release from fetal mouse long bone organ cultures. Furthermore, caldecrin suppressed the formation of osteoclasts from bone marrow cells by inhibiting the receptor activator of nuclear factor-κ B ligand (RANKL)-stimulated phospholipase Cγ-calcium oscillation-calcineurin-nuclear factor of activated T-cells, cytoplasmic 1 pathway. Caldecrin also suppressed the bone resorption activity of mature osteoclasts by preventing RANKL-stimulated Src activation, calcium entry, and actin ring formation. In vivo and in vitro studies have indicated that caldecrin is a unique multifunctional protease with anti-osteoclastogenic activities that are distinct from its protease activity. Caldecrin might be a potential therapeutic target for the treatment of osteolytic diseases such as osteoporosis and osteoarthritis. This mini-review describes caldecrin’s historical background and its mechanisms of action.
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Wauquier F, Léotoing L, Philippe C, Spilmont M, Coxam V, Wittrant Y. Pros and cons of fatty acids in bone biology. Prog Lipid Res 2015; 58:121-45. [PMID: 25835096 DOI: 10.1016/j.plipres.2015.03.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/06/2015] [Accepted: 03/23/2015] [Indexed: 12/12/2022]
Abstract
Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response.
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Affiliation(s)
- Fabien Wauquier
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Laurent Léotoing
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Claire Philippe
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Mélanie Spilmont
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Véronique Coxam
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France
| | - Yohann Wittrant
- INRA, UMR 1019, UNH, CRNH Auvergne, F-63009 Clermont-Ferrand, France; Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, F-63000 Clermont-Ferrand, France; Equipe Alimentation, Squelette et Métabolismes, France.
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Suzuki H, Yamamoto T. Amylin-like immunoreactivity in pancreatic X cells of the black-spotted frog Rana (Pelophylax) nigromaculata. Tissue Cell 2014; 46:535-9. [PMID: 25458814 DOI: 10.1016/j.tice.2014.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 12/01/2022]
Abstract
tIn this study, we investigated the presence of ovoid or ellipsoidal amylin-immunoreactive cells of the pancreatic islets of the black-spotted frog Rana (Pelophylax) nigromaculata. Using double immunofluorescent staining, all amylin-immunoreactive cells were shown to be immuno-negative for insulin, glucagon, and somatostatin, and they were often observed in peripheral regions of clusters of insulin-immunoreactive cells. Under immunoelectron microscopy, amylin-immunoreactive signals were detected on the secretory granules in a specific type of endocrine cells. From our results, we conclude that the amylin-immunoreactive cells correspond to X cells among the 4 distinct types of endocrine cells (B, A/PP, D, and X) previously identified in the frog. Amylin secreted from X cells may regulate the hormone secretion from A/PP cells and/or B cells through a paracrine mechanism.
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Affiliation(s)
- Hirohumi Suzuki
- Department of Biology, Fukuoka University of Education, Akamabunkyo-machi 1-1, Munakata, Fukuoka 811-4192, Japan.
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15
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Abstract
UNLABELLED Despite effective weight reduction, the impact of bariatric surgery on bone is a major concern. Mechanisms include decreased mechanical loading, calcium and vitamin D malabsorption, deficiency in other nutrients, and alterations in fat- and gut-derived hormones. The evidence to support clinical care pathways to prevent bone loss and fractures is at this point weak. INTRODUCTION There is a growing concern regarding the potential deleterious impact of bariatric surgery on bone metabolism. This comprehensive review addresses this controversial topic. METHODS We reviewed and analyzed articles evaluating bone metabolism and mechanisms for the ensuing putative bone loss in adult patients exclusively undergoing Roux-en-Y gastric bypass (RYGB) surgery, for the period spanning 1942 till September 2012. RESULTS Mechanisms identified to contribute to alterations in bone metabolism after bypass surgery include: decreased mechanical loading, calcium and vitamin D malabsorption with secondary hyperparathyroidism, deficiency in other nutrients, in addition to alterations in adipokines, gonadal steroids, and gut-derived hormones favoring bone loss, with the exception of serotonin and glucagon-like peptide-1. The relative contribution of each of these hormones to changes in bone homeostasis after bypass surgery remains undefined. Bone loss reflected by a decline in bone mineral density (BMD) and an increase in bone turnover markers have been reported in many studies, limited for the most part by the exclusive use of dual energy X-ray absorptiometry. Well-designed long-term prospective trials with fractures as an outcome, and studies investigating the magnitude, reversibility, and impact of the observed metabolic changes on fracture outcomes are lacking. CONCLUSION Robust conclusions regarding bone loss and fracture outcome after RYGB surgery cannot be drawn at this time. Although not evidence based, baseline evaluation and sequential monitoring with measurement of BMD and calciotropic hormones seem appropriate, with adequate calcium and vitamin D replacement. Beneficial interventions remain unclear.
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Affiliation(s)
- M P Hage
- Department of Internal Medicine, Division of Endocrinology, Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut-Medical Center, PO BOX: 11-0236, Riad El Solh, 1107 2020, Beirut, Lebanon
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16
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Abstract
Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.
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Affiliation(s)
- Sascha Kopic
- Department of Surgery and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
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17
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Gutiérrez-Rojas I, Lozano D, Nuche-Berenguer B, Moreno P, Acitores A, Ramos-Álvarez I, Rovira A, Novials A, Martín-Crespo E, Villanueva-Peñacarrillo ML, Esbrit P. Amylin exerts osteogenic actions with different efficacy depending on the diabetic status. Mol Cell Endocrinol 2013. [PMID: 23178165 DOI: 10.1016/j.mce.2012.11.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Amylin displays osteogenic features, but its role in diabetic osteopenia is unclear. We examined the possible osteogenic action of amylin infusion for 3days into fructose-induced insulin-resistant (IR) and streptozotocin-induced type 2 diabetic (T2D) and normal (N) rats. Amylin failed to affect glycaemia or parathyroid hormone levels in any group, but reduced hyperinsulinemia in IR rats. In N rats, amylin increased bone formation rate and reduced osteoclast surface and erosive surface in the femoral metaphysis, and increased osteoprotegerin (OPG)/receptor activator of NFκB ligand (RANKL) mRNA ratio in the tibia. In T2D rats, amylin normalized trabecular structure parameters and increased osteoblast number and osteocalcin (OC) expression in long bones. In contrast, in IR rats, no apparent osteogenic effect of amylin in the femur was observed, although both OC and OPG/RANKL ratio were increased in the tibia. Our findings demonstrate a different osteogenic efficacy of amylin in two diabetic settings.
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Affiliation(s)
- I Gutiérrez-Rojas
- Departamento de Metabolismo, Nutrición y Hormonas, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, Madrid, Spain
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18
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Amelio PD, Panico A, Spertino E, Isaia GC. Energy metabolism and the skeleton: Reciprocal interplay. World J Orthop 2012; 3:190-8. [PMID: 23330074 PMCID: PMC3547113 DOI: 10.5312/wjo.v3.i11.190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 07/31/2012] [Accepted: 10/20/2012] [Indexed: 02/06/2023] Open
Abstract
The relation between bone remodelling and energy expenditure is an intriguing, and yet unexplained, challenge of the past ten years. In fact, it was only in the last few years that the skeleton was found to function, not only in its obvious roles of body support and protection, but also as an important part of the endocrine system. In particular, bone produces different hormones, like osteocalcin (OC), which influences energy expenditure in humans. The undercarboxylated form of OC has a reduced affinity for hydroxyapatite; hence it enters the systemic circulation more easily and exerts its metabolic functions for the proliferation of pancreatic β-cells, insulin secretion, sensitivity, and glucose tolerance. Leptin, a hormone synthesized by adipocytes, also has an effect on both bone remodelling and energy expenditure; in fact it inhibits appetite through hypothalamic influence and, in bone, stimulates osteoblastic differentiation and inhibits apoptosis. Leptin and serotonin exert opposite influences on bone mass accrual, but several features suggest that they might operate in the same pathway through a sympathetic tone. Serotonin, in fact, acts via two opposite pathways in controlling bone remodelling: central and peripheral. Serotonin product by the gastrointestinal tract (95%) augments bone formation by osteoblast, whereas brain-derived serotonin influences low bone mineral density and its decrease leads to an increase in bone resorption parameters. Finally, amylin (AMY) acts as a hormone that alters physiological responses related to feeding, and plays a role as a growth factor in bone. In vitro AMY stimulates the proliferation of osteoblasts, and osteoclast differentiation. Here we summarize the evidence that links energy expenditure and bone remodelling, with particular regard to humans.
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19
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Togari A, Arai M, Kondo H, Kodama D, Niwa Y. The neuro-osteogenic network: The sympathetic regulation of bone resorption. Japanese Dental Science Review 2012; 48:61-70. [DOI: 10.1016/j.jdsr.2011.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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20
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Abstract
With the increasing worldwide prevalence of diabetes the resulting complications, their consequences and treatment will lead to a greater social and financial burden on society. One of the many organs to be affected is bone. Loss of bone is observed in type 1 diabetes, in extreme cases mirroring osteoporosis, thus a greater risk of fracture. In the case of type 2 diabetes, both a loss and an increase of bone has been observed, although in both cases the quality of the bone overall was poorer, again leading to a greater risk of fracture. Once a fracture has occurred, healing is delayed in diabetes, including nonunion. The reasons leading to such changes in the state of the bone and fracture healing in diabetes is under investigation, including at the cellular and the molecular levels. In comparison with our knowledge of events in normal bone homeostasis and fracture healing, that for diabetes is much more limited, particularly in patients. However, progress is being made, especially with the use of animal models for both diabetes types. Identifying the molecular and cellular changes in the bone in diabetes and understanding how they arise will allow for targeted intervention to improve diabetic bone, thus helping to counter conditions such as Charcot foot as well as preventing fracture and accelerating healing when a fracture does occur.
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21
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22
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Wang L, Shi X, Zhao R, Halloran BP, Clark DJ, Jacobs CR, Kingery WS. Calcitonin-gene-related peptide stimulates stromal cell osteogenic differentiation and inhibits RANKL induced NF-kappaB activation, osteoclastogenesis and bone resorption. Bone 2010; 46:1369-79. [PMID: 19962460 PMCID: PMC2854244 DOI: 10.1016/j.bone.2009.11.029] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 11/23/2009] [Accepted: 11/25/2009] [Indexed: 11/18/2022]
Abstract
Previously we observed that capsaicin treatment in rats inhibited sensory neuropeptide signaling, with a concurrent reduction in trabecular bone formation and bone volume, and an increase in osteoclast numbers and bone resorption. Calcitonin-gene-related peptide (CGRP) is a neuropeptide richly distributed in sensory neurons innervating the skeleton and we postulated that CGRP signaling regulates bone integrity. In this study we examined CGRP effects on stromal and bone cell differentiation and activity in vitro. CGRP receptors were detected by immunocytochemical staining and real time PCR assays in mouse bone marrow stromal cells (BMSCs) and bone marrow macrophages (BMMs). CGRP effects on BMSC proliferation and osteoblastic differentiation were studied using BrdU incorporation, PCR products, alkaline phosphatase (ALP) activity, and mineralization assays. CGRP effects on BMM osteoclastic differentiation and activity were determined by quantifying tartrate-resistant acid phosphatase positive (TRAP(+)) multinucleated cells, pit erosion area, mRNA levels of TRAP and cathepsin K, and nuclear factor-kappaB (NF-kappaB) nuclear localization. BMSCs, osteoblasts, BMMs, and osteoclasts all expressed CGRP receptors. CGRP (10(-10)-10(-8) M) stimulated BMSC proliferation, up-regulated the expression of osteoblastic genes, and increased ALP activity and mineralization in the BMSCs. In BMM cultures CGRP (10(-8) M) inhibited receptor activator of NF-kappaB ligand (RANKL) activation of NF-kappaB. CGRP also down-regulated osteoclastic genes like TRAP and cathepsin K, decreased the numbers of TRAP(+) cells, and inhibited bone resorption activity in RANKL stimulated BMMs. These results suggest that CGRP signaling maintains bone mass both by directly stimulating stromal cell osteoblastic differentiation and by inhibiting RANKL induced NF-kappaB activation, osteoclastogenesis, and bone resorption.
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Affiliation(s)
- Liping Wang
- Physical Medicine and Rehabilitation Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California
| | - Xiaoyou Shi
- Physical Medicine and Rehabilitation Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California
| | - Rong Zhao
- Physical Medicine and Rehabilitation Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California
| | - Bernard P. Halloran
- Endocrine Research Unit, Veterans Affairs Medical Center San Francisco, San Francisco, California
- Department of Medicine, University of California, San Francisco, California
| | - David J. Clark
- Anesthesiology Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Department of Anesthesia, Stanford University School of Medicine, Stanford, California
| | - Christopher R. Jacobs
- Bone and Joint Rehabilitation R & D Center, Veterans Affairs Palo Alto Health care System, Palo Alto, California
- Department of Mechanical Engineering, Stanford University School of Engineering, Stanford, California
| | - Wade S. Kingery
- Physical Medicine and Rehabilitation Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California
- Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California
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23
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Wojcik MH, Meenaghan E, Lawson EA, Misra M, Klibanski A, Miller KK. Reduced amylin levels are associated with low bone mineral density in women with anorexia nervosa. Bone 2010; 46:796-800. [PMID: 19931436 PMCID: PMC2824019 DOI: 10.1016/j.bone.2009.11.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 10/23/2009] [Accepted: 11/11/2009] [Indexed: 11/27/2022]
Abstract
CONTEXT Anorexia nervosa, characterized by extreme low body weight due to reduced nutrient intake, is associated with severe bone loss. Peptide hormones, including amylin, GIP, and GLP2, are released immediately after nutrient intake and may be involved in the regulation of bone turnover. OBJECTIVE To investigate fasting levels of amylin, GIP, and GLP2 and their relationships with bone mineral density (BMD) in women with anorexia nervosa compared to healthy controls. DESIGN Cross-sectional. SETTING Clinical Research Center. STUDY PARTICIPANTS 15 women with anorexia nervosa and 16 healthy controls. INTERVENTION None. MAIN OUTCOME MEASURES Fasting serum amylin, GIP, and GLP2, and BMD. RESULTS Women with anorexia nervosa had significantly lower fasting serum amylin and GIP levels than healthy controls. Fasting serum GLP2 levels were not significantly different between groups. Fasting amylin levels were positively associated with BMD and Z-score at the PA spine, total hip, and femoral neck. Fasting amylin levels were also positively associated with weight and percent fat; after controlling for these variables, amylin was still a significant predictor of BMD and Z-score at the femoral neck and of Z-score at the total hip. In the anorexia nervosa group, there was a trend toward an inverse association between amylin and C-terminal telopeptide (CTX) levels (R=-0.47, p=0.08). GIP and GLP2 levels did not predict BMD at any site. CONCLUSION Decreased secretion of amylin may be a mechanism through which reduced nutrient intake adversely affects BMD in anorexia nervosa.
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Affiliation(s)
- Monica H Wojcik
- Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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24
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Ellegaard M, Thorkildsen C, Petersen S, Petersen JS, Jørgensen NR, Just R, Schwarz P, Ramirez MT, Stahlhut M. Amylin(1-8) is devoid of anabolic activity in bone. Calcif Tissue Int 2010; 86:249-60. [PMID: 20127324 DOI: 10.1007/s00223-010-9338-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Accepted: 12/22/2009] [Indexed: 11/26/2022]
Abstract
Amylin(1-8), a cyclic peptide consisting of the eight N-terminal amino acids of the 37-amino acid peptide amylin, has been shown to induce proliferation of primary osteoblasts and to induce bone formation in healthy male mice, whereas no data on efficacy in bone disease-related models have been reported. Therefore, we evaluated any effects of amylin(1-8) in ovariectomized rats with established osteopenia, a model for postmenopausal osteoporosis. At doses up to 100 nmol/kg/day, a dose highly effective in healthy mice, amylin(1-8) was unable to increase bone mineral density in ovariectomized rats during an 8-week treatment period. Histomorphometric analysis of the tibia indicated that amylin(1-8) did not change bone histomorphometric parameters. In an attempt to verify any potential biological effects of amylin(1-8), we investigated the efficacy of this peptide in various in vitro assays. Experiments designed to confirm previously published results on the proliferative effects of amylin(1-8) on primary osteoblasts failed to show any response. Amylin(1-8) was able to partially displace (125)I-rat amylin(1-37) from amylin receptors composed of the calcitonin receptor and RAMP1, indicating specific interaction of the peptide with the amylin binding site. However, in vitro efficacy assays with amylin(1-8) in calcitonin receptor-RAMP-positive HEK293T and MCF7 cells failed to reveal any agonist activity of amylin(1-8), whereas amylin(1-37) showed the expected agonist activity. In conclusion, our results indicate that amylin(1-8) does not show agonist activity on amylin receptors, does not affect osteoblast proliferation, and is devoid of anabolic activity in bone.
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MESH Headings
- Amyloid/pharmacology
- Amyloid/therapeutic use
- Anabolic Agents/pharmacology
- Anabolic Agents/therapeutic use
- Animals
- Animals, Newborn
- Binding Sites/drug effects
- Binding Sites/physiology
- Bone Diseases, Metabolic/drug therapy
- Bone Diseases, Metabolic/metabolism
- Bone Diseases, Metabolic/physiopathology
- Bone Regeneration/drug effects
- Bone Regeneration/physiology
- Cell Line
- Cell Line, Tumor
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Female
- Humans
- Intracellular Signaling Peptides and Proteins/drug effects
- Intracellular Signaling Peptides and Proteins/metabolism
- Islet Amyloid Polypeptide
- Membrane Proteins/drug effects
- Membrane Proteins/metabolism
- Mice
- Osteoblasts/drug effects
- Osteoblasts/metabolism
- Osteogenesis/drug effects
- Osteogenesis/physiology
- Ovariectomy
- Peptide Fragments/pharmacology
- Peptide Fragments/therapeutic use
- Peptides/pharmacology
- Peptides/therapeutic use
- Rats
- Rats, Sprague-Dawley
- Receptor Activity-Modifying Protein 1
- Receptor Activity-Modifying Proteins
- Receptors, Calcitonin/drug effects
- Receptors, Calcitonin/metabolism
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25
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Abstract
Amylin is a member of the calcitonin family of hormones cosecreted with insulin from the pancreatic beta-cells that can act as an osteoblast mitogen and as an inhibitor of bone resorption in mice and humans. The aim of this study was to investigate the role of amylin on bone formation and some egg parameters in hens. The study was performed in 60 hens aged 10 wk. Thirty hens constituting the treatment group were s.c. injected with amylin at a 75 microg/kg dose every other day. The remaining hens were used as the control group. Five birds from the treatment and control groups were slaughtered at 14, 16, 18, and 20 wk of age and serum and bone parameters were compared between the treatment and control groups. The remaining 20 hens were fed without any amylin injection until 35 wk. All hens at the end of the 35th week were slaughtered and then serum, bone, and egg parameters were assessed. In the treatment group, bone calcium levels increased, whereas serum calcium levels decreased. This dose of amylin also increased the cortical width of tibiotarsuses in hens. Eggshell thickness was found thicker in the treatment group than in the control group. Overall, the results of this study suggest that amylin may stimulate the bone and eggshell quality by increasing calcium uptake from the bloodstream and may influence the sustainability of yield in hens.
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Affiliation(s)
- S Guzel
- Department of Biochemistry, University of Uludag, Gorukle Campus, 16059, Bursa, Turkey.
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26
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Naot D, Cornish J. The role of peptides and receptors of the calcitonin family in the regulation of bone metabolism. Bone 2008; 43:813-8. [PMID: 18687416 DOI: 10.1016/j.bone.2008.07.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 07/09/2008] [Accepted: 07/11/2008] [Indexed: 11/28/2022]
Abstract
The 'calcitonin family' is a group of peptide hormones that share structural similarities with calcitonin, and includes calcitonin gene-related peptide (CGRP), amylin, adrenomedullin and adrenomedullin 2 (intermedin). These hormones are produced by different tissues, with calcitonin being produced in thyroid C cells, alphaCGRP predominantly in neural tissue, amylin in beta-islet cells of the pancreas and adrenomedullin in many tissues and cell types. Bone appears to be a common target for all the peptides of the calcitonin family, although the specific bone effects of the peptides vary. Administration of calcitonin produces rapid lowering of serum calcium levels, mainly through inhibition of bone resorption by osteoclasts. In vitro and in a number of animal experimental models, amylin and CGRP are also effective in inhibiting osteoclast activity and bone resorption. Amylin, adrenomedullin and CGRP can also affect cells of the osteoblast lineage, inducing osteoblast proliferation and promoting bone formation. Receptors for the peptides of the calcitonin family are formed by heterodimerization of the calcitonin receptor (CTR) or calcitonin receptor-like receptor (CLR) with receptor activity modifying proteins (RAMPs). Although the different combinations of these proteins create receptors with distinct ligand specificities, there is a degree of cross-reactivity and the receptors are able to bind other ligands from the family, usually with lower affinity. Analysis of the expression of the receptors for the calcitonin family in 16 samples of human osteoblasts showed high levels of CLR and RAMP1, low levels of RAMP2 and no expression of RAMP3 or CTR. Recent studies of the bone phenotype of knockout animals lacking the calcitonin, alphaCGRP or amylin gene indicated that in this experimental system the main physiological role of amylin in bone is the inhibition of bone resorption, that of CGRP is the activation of bone formation, while calcitonin, unexpectedly appears to be inhibiting bone formation without affecting bone resorption. Further investigations will be required to determine the mechanisms of action of calcitonin peptides in bone and their significance to human bone physiology.
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Affiliation(s)
- D Naot
- Department of Medicine, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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27
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Abstract
Osteoclasts are bone-resorbing cells derived from hematopoietic precursors of the monocyte-macrophage lineage. Besides the well known Receptor Activator of Nuclear factor-kappaB (RANK), RANK ligand and osteoprotegerin axis, a variety of factors tightly regulate osteoclast formation, adhesion, polarization, motility, resorbing activity and life span, maintaining bone resorption within physiological ranges. Receptor-mediated osteoclast regulation is rather complex. Nuclear receptors, cell surface receptors, integrin receptors and cell death receptors work together to control osteoclast activity and prevent both reduced or increased bone resorption. Here we will discuss the signal transduction pathways activated by the main osteoclast receptors, integrating their function and mechanisms of action.
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Affiliation(s)
- Andrea Del Fattore
- Department of Experimental Medicine, University of L'Aquila, Via Vetoio, Coppito 2, 67100 L'Aquila, Italy
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28
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Li L, Hölscher C. Common pathological processes in Alzheimer disease and type 2 diabetes: a review. ACTA ACUST UNITED AC. 2007;56:384-402. [PMID: 17920690 DOI: 10.1016/j.brainresrev.2007.09.001] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 09/01/2007] [Accepted: 09/05/2007] [Indexed: 02/07/2023]
Abstract
Alzheimer disease (AD) and type 2 diabetes mellitus (T2DM) are conditions that affect a large number of people in the industrialized countries. Both conditions are on the increase, and finding novel treatments to cure or prevent them are a major aim in research. Somewhat surprisingly, AD and T2DM share several molecular processes that underlie the respective degenerative developments. This review describes and discusses several of these shared biochemical and physiological pathways. Disturbances in insulin signalling appears to be the main common impairment that affects cell growth and differentiation, cellular repair mechanisms, energy metabolism, and glucose utilization. Insulin not only regulates blood sugar levels but also acts as a growth factor on all cells including neurons in the CNS. Impairment of insulin signalling therefore not only affects blood glucose levels but also causes numerous degenerative processes. Other growth factor signalling systems such as insulin growth factors (IGFs) and transforming growth factors (TGFs) also are affected in both conditions. Also, the misfolding of proteins plays an important role in both diseases, as does the aggregation of amyloid peptides and of hyperphosphorylated proteins. Furthermore, more general physiological processes such as angiopathic and cytotoxic developments, the induction of apoptosis, or of non-apoptotic cell death via production of free radicals greatly influence the progression of AD and T2DM. The increase of detailed knowledge of these common physiological processes open up the opportunities for treatments that can prevent or reduce the onset of AD as well as T2DM.
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Li J, Kreicbergs A, Bergström J, Stark A, Ahmed M. Site-specific CGRP innervation coincides with bone formation during fracture healing and modeling: A study in rat angulated tibia. J Orthop Res 2007; 25:1204-12. [PMID: 17503519 DOI: 10.1002/jor.20406] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sensory neuropeptide involved in local bone turnover is known, but poorly understood. In the present study, we analyze the occurrence of neuronal CGRP during healing and modeling of straight and angular tibial fractures in 74 rats. Bone healing and modeling was assessed by radiography and reinnervation by semi-quantitative immunohistochemistry method at fracture site between 1-12 weeks postfracture. The regenerating nerve fibers containing CGRP were observed in fracture callus as well as in close proximity to chondrocytes, with woven bone in both fractures already at week 1. Notably, it located predominantly on the concave side of angulated fracture in the manner of sprouting into bone from weeks 3 to 5 postfracture. In both fractures, fracture calluses peaked radiographically at week 3 postfracture. In angulated fracture, a reduction of 11% in callus thickness on convex side and an increase of 365% on concave side were noted from weeks 3 to 12. A 27-fold increase in total neuronal CGRP in straight fracture and 38-fold increases in angular fracture compared to intact bone was observed at week 3. In both types of fracture, neuronal CGRP was greater on the concave side than the convex; this difference was more pronounced in the angulated fracture. CGRP immunoreactivity clearly coincides with amount of new bone formation especially on the concave side of angulated fracture. The combined results suggest that fracture evokes an intense, localized in-growth of new nerve fibers containing CGRP, which may prove to be a prerequisite of fracture healing and modeling.
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Affiliation(s)
- Jian Li
- Section of Orthopaedics, Institution of Molecular Medicine and Surgery, Research Center M3:02, Karolinska University Hospital, SE 171 76, Stockholm, Sweden.
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Abstract
Experimental studies have generally shown that increased sympathetic nervous activity causes bone loss via an increase in bone resorption and a decrease in bone formation. Increased bone resorption is based on the stimulation of both osteoclast formation and osteoclast activity. These effects are associated with beta2-adrenergic activity towards both osteoblastic and osteoclastic cells. Decreased bone formation is based on the inhibition of osteoblastic activity through beta2-adrenergic receptors on osteoblasts. Such findings indicate that beta-blockers may be effective against osteoporosis, in which case there is increased sympathetic activity. In fact, in a population-based, case-control study, the current use of beta-blockers has been demonstrated to be associated with a reduced risk of fractures. These clinical studies suggest that pharmacological blockade of the beta-adrenergic system is beneficial to the human skeleton. In another prospective study, however, no association between beta-blocker use and fracture risk was shown in perimenopausal and older women. To confirm this important new therapeutic avenue to prevent bone loss, the relationship between the pharmacological effectiveness of beta-blockers and the pathogenesis of osteoporosis must be explored in detail.
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Affiliation(s)
- Akifumi Togari
- Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya 464-8650, Japan.
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Davey RA, Moore AJ, Chiu MWS, Notini AJ, Morris HA, Zajac JD. Effects of amylin deficiency on trabecular bone in young mice are sex-dependent. Calcif Tissue Int 2006; 78:398-403. [PMID: 16830202 DOI: 10.1007/s00223-005-0286-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 03/07/2006] [Indexed: 11/24/2022]
Abstract
Amylin deficiency in mice results in late-onset osteopenia. Sex differences have been identified in insulin secretion in Amylin-overexpressing transgenic mice, suggesting a possible interaction of sex steroids, growth factors, or cytokines and amylin. The aim of the current study was to compare the effects of amylin deficiency on bone in young and adult male and female mice. The metaphyses of the distal femora from male and female Amylin-deficient mice at 4, 6, and 26 weeks of age were assessed by bone histomorphometry. Femoral length was increased in Amylin-deficient male mice compared to wild-type (WT) mice at 26 weeks of age (P < 0.005) but not in females. This was associated with an increase in growth plate height in Amylin-deficient males at 4 (P < 0.01) and 6 (P < 0.05) weeks of age. Furthermore, young Amylin-deficient males had decreased trabecular number at 4 weeks of age (P < 0.05) and increased trabecular thickness at 4 and 6 weeks of age (P < 0.05) compared to WT mice, with no net change in trabecular bone volume. These effects of amylin deficiency were not observed in female mice. In conclusion, this study demonstrates that amylin deficiency exerts effects on bone during growth that are sex-dependent and suggest a possible interaction between amylin and testosterone, growth factors, or cytokines to regulate bone cell metabolism.
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Affiliation(s)
- R A Davey
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia.
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Affiliation(s)
- I R Reid
- Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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Abstract
Lactoferrin is an iron-binding glycoprotein that belongs to the transferrin family. It is present in breast milk, in epithelial secretions, and in the secondary granules of neutrophils. In healthy subjects lactoferrin circulates at concentrations of 2-7 x 10(-6) g/ml. Lactoferrin is a pleiotropic factor with potent antimicrobial and immunomodulatory activities. Recently, we have shown that lactoferrin can also promote bone growth. At physiological concentrations, lactoferrin potently stimulates the proliferation and differentiation of primary osteoblasts and also acts as a survival factor inhibiting apoptosis induced by serum withdrawal. Lactoferrin also affects osteoclast formation and, in murine bone marrow culture, lactoferrin potently inhibits osteoclastogenesis. In vivo, local injection of lactoferrin above the hemicalvaria of adult mice results in substantial increases in the dynamic histomorphometric indices of bone formation and bone area. The mitogenic effect of lactoferrin in osteoblast-like cells is mediated mainly through LRP1, a member of the family of low-density lipoprotein receptor-related proteins that are primarily known as endocytic receptors. Using confocal laser scanning microscopy, we demonstrated that fluorescently labeled lactoferrin is endocytosed and can be visualized in the cytoplasm of primary osteoblastic cells. Lactoferrin also induces activation of p42/44 MAPK signaling in primary osteoblasts, but the two pathways seem to operate independently as activation of MAPK signaling, but not endocytosis, is necessary for the mitogenic effect of lactoferrin. We conclude that lactoferrin may have a physiological role in bone growth and healing, and a potential therapeutic role as an anabolic factor in osteoporosis.
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Affiliation(s)
- Dorit Naot
- Department of Medicine, University of Auckland, Auckland, New Zealand.
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Ishizuka K, Hirukawa K, Nakamura H, Togari A. Inhibitory effect of CGRP on osteoclast formation by mouse bone marrow cells treated with isoproterenol. Neurosci Lett 2005; 379:47-51. [PMID: 15814197 DOI: 10.1016/j.neulet.2004.12.046] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Revised: 12/20/2004] [Accepted: 12/20/2004] [Indexed: 01/20/2023]
Abstract
The present study was designed to elucidate the mode of action of isoproterenol (Isp; adrenergic beta-agonist) and to characterize the effect of the calcitonin gene-related peptide (CGRP; sensory neuropeptide) on osteoclast formation induced by Isp in a mouse bone marrow culture system. Treatment of mouse bone marrow cells with Isp generated tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNCs) capable of excavating resorptive pits on dentine slices, and caused an increase in receptor activator of NF-kappaB ligand (RANKL) and a decrease in osteoprotegerin (OPG) production by the marrow cells. The osteoclast formation was significantly inhibited by OPG, suggesting the involvement of the RANKL-RANK system. CGRP inhibited the osteoclast formation caused by Isp or soluble RANKL (s-RANKL) but had no influence on RANKL or OPG production by the bone marrow cells treated with Isp, suggesting that CGRP inhibited the osteoclast formation by interfering with the action of RANKL produced by the Isp-treated bone marrow cells without affecting RANKL or OPG production. This in vitro data suggest the physiological interaction of sympathetic and sensory nerves in osteoclastogenesis in vivo.
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Affiliation(s)
- Kyoko Ishizuka
- Department of Pharamacology, School of Dentistry, Aichi-Gakuin University, Nagoya 464-8650, Japan
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35
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Abstract
The most potent actions of amylin that occur at physiological plasma concentrations include inhibition of food intake, gastric emptying, acid and digestive enzyme secretion, and glucagon secretion. These actions share a common outcome; they each help regulate the rate at which nutrients (including glucose) appear in the blood (Ra). Amylin physiologically orchestrates, via several parallel processes, the rate of entry of nutrient into the circulation, as shown schematically in Fig. 1. In this way, amylin's function may be viewed as complementary to that of insulin (secreted from the same pancreatic beta-cells), which orchestrates the exit of nutrient from blood and its storage in peripheral tissues. The following discussion addresses the emerging picture that, although amylin is co-secreted with an endocrine hormone from endocrine tissue (the pancreatic islets), the target for its most potent and physiologically relevant effects appears to be the central nervous system. Amylin thus may be primarily regarded as a neuroendocrine hormone (Young et al., 2000).
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Affiliation(s)
- Andrew Young
- Amylin Pharmaceuticals, Inc., San Diego, California, USA
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36
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Abstract
The actions of amylin on bone have been reviewed in several publications (MacIntyre, 1992a,b; MacIntyre et al., 1991; Reid and Cornish, 1996; Tamura et al., 1992a,b; Zaidi et al., 1990a,c, 1993b). MacIntyre proposed that amylin or its derivatives or agonists would be useful for treating bone disorders, such as osteoporosis, Paget's disease, or bone loss resulting from malignancy, endocrine disorders, autoimmune arthritides, breakage and fracture, immobility and disease, or hypercalcaemia (MacIntyre, 1995).
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Affiliation(s)
- Andrew Young
- Amylin Pharmaceuticals, Inc., San Diego, California, USA
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Abstract
Despite clear evidence for a distinct amylin pharmacology and localization of such pharmacology to sites such as the nucleus accumbens,efforts to clone an amylin receptor were fruitless for over a decade. This enigma led many to doubt the status of amylin as a bona fide hormone. Yet it became apparent during those cloning efforts that, whatever the amylin receptor was, it was somehow similar to a calcitonin receptor. The enigma of the amylin receptor was solved following the identification of receptor activity modifying proteins (RAMPs). These single transmembrane spanning molecules, when associated with a calcitonin receptor, altered its pharmacology from calcitonin-preferring to amylin-preferring. With at least two forms of the calcitonin receptor and three forms of RAMP, there is the potential for six subtypes of amylin receptors. Of these, two appear to predominate. The CTa (shorter form) calcitonin receptor, dimerized with RAMP1 [amylin 1 (a) receptor], appears to represent binding sites at the nucleus accumbens and the subfornical organ. Binding sites at area postrema appear to be composed of CTa + RAMP3 [amylin3 (a) receptors]. Thus far, RAMP proteins have been associated in vivo only with the CT/CLR receptor system. It is presently unknown whether RAMPs are more general modulators of receptor function, dynamically modifying responsivity with time or across other receptor classes. The largest and first identified amylin-binding field was in the nucleus accumbens. The function of these receptors is yet undetermined, but because the nucleus accumbens is within the blood-brain barrier, the cognate ligand is unlikely to be circulating amylin. Dense amylin binding is present at the circumventricular organs, including the subfornical organ, the organum vasculosum lateralis terminalis (OVLT), and the area postrema. There is no diffusional (blood-brain) barrier at these structures, so they most likely respond to circulating (beta-cell-derived) amylin. Despite pharmacological evidence of amylin sensitivity in several peripheral tissues, selective amylin binding outside of the brain is observed only in the renal cortex. The newly designated amylinomimetic drug class was defined on the basis of its unique pharmacology prior to the molecular characterization of amylin receptors. Currently, the class includes any agent that acts as antagonist at characterized amylin receptors. Several peptides, typically analogs of truncated salmon calcitonin, have been developed as potent and selective amylin antagonists and have been useful in identifying amylinergic responses. Of these, AC187 (30Asn32Tyr[8-32]sCT; Amylin Pharmaceuticals Inc.) is particularly selective and potent, and has been most often cited in studies using amylin antagonists. Antagonism of a response with an order of potency of AC187> AC66 > CGRP[8-37] is suggestive that it is mediated via amylin receptors. Activation of a response with salmon calcitonin (sCT) > amylin >calcitonin gene-related peptide (CGRP) > mammalian CT suggests activation via the amylinl (a) receptor, while sCT = amylin >> CGRP >mammalian CT suggests activation via amylin3 (a) receptors. Absence of response to other ligands (e.g., adrenomedullin) is useful for excluding certain pharmacologies.
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Affiliation(s)
- Andrew Young
- Amylin Pharmaceuticals, Inc., San Diego, California, USA
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Samonina G, Kopylova G, Lukjanzeva G, Zhuykova S, Smirnova E, German S, Guseva A. Antiulcer effects of amylin: a review. Pathophysiology 2004; 11:1-6. [PMID: 15177509 DOI: 10.1016/j.pathophys.2003.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2002] [Accepted: 10/09/2003] [Indexed: 01/22/2023] Open
Abstract
Amylin belongs to the calcitonin peptide family. Amylin is a peptide synthesized not only in the beta cells of pancreatic islets, but in small quantities also in other organs like in the intestinal and gastric mucosa, lungs and central nervous system. It is located in the same secretory granules as insulin. Amylin participates in the maintenance of glucose and calcium homeostasis. It also inhibits food intake and decreases body weight. Furthermore, amylin inhibits gastric acid secretion. It protects the gastric mucosa in ulcer models like stress, vagal stimulation, ethanol, acetic acid, reserpine and serotonine administration and pylorus ligation. This protective antiulcer is seen not only at pharmacological but also at near-physiological doses-0.5mkg/kg. Moreover amylin also exerts curative properties in the acetic acid and indomethacin ulcer models. Amylin decreases the aggressive factors like acid-pepsin secretion, increases mast cell stability and increases protective mechanisms like bicarbonate gastric secretion, dilates blood vessels, and it increases lymphatic mesenteric activity. Amylin seems to be a powerful protector of gastric mucosa in animals by increasing the stability of gastric mucosa. Further research remains, however, to be done.
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Affiliation(s)
- G.E. Samonina
- Department of Human and Animal Physiology, School of Biology, Moscow State Lomonosov University, Vorobjevy Gory 1, Building 12, Moscow 119899, Russia
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39
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Abstract
Calcitonin (CT) was first reported as a hypocalcemic principle, initially thought to originate from the parathyroid gland, a view subsequently corrected to an origin from parafollicular C-cells. Human CT is a 32 amino acid peptide with an N-terminal disulphide bridge and a C-terminal prolineamide residue, shown to potently inhibit bone resorption. More recent studies have demonstrated that this may take place through a direct osteoclastic action. A number of osteoclast CT receptors have subsequently been characterized and particular receptor regions necessary for ligand binding and intracellular signaling identified. Its potent anti-resorptive effect has led to its use in treating Paget's bone disease, osteoporosis, hypercalcaemia and osteogenesis imperfecta. This review summarises some key aspects of its synthesis, structure and its actions at the cellular and molecular levels, and leads on to its therapeutic uses that have emerged since its discovery as well as possibilities for future clinical applications.
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Affiliation(s)
- Angela M Inzerillo
- Mount Sinai Bone Program, Departments of Medicine and Geriatrics, Mount Sinai School of Medicine, and Bronx Veteran's Affairs, New York, NY, USA
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Okamoto F, Kajiya H, Fukushima H, Jimi E, Okabe K. Prostaglandin E2 activates outwardly rectifying Cl(-) channels via a cAMP-dependent pathway and reduces cell motility in rat osteoclasts. Am J Physiol Cell Physiol 2004; 287:C114-24. [PMID: 15044156 DOI: 10.1152/ajpcell.00551.2003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined changes in electrical and morphological properties of rat osteoclasts in response to prostaglandin (PG)E(2). PGE(2) (>10 nM) stimulated an outwardly rectifying Cl(-) current in a concentration-dependent manner and caused a long-lasting depolarization of cell membrane. This PGE(2)-induced Cl(-) current was reversibly inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), and tamoxifen. The anion permeability sequence of this current was I(-) > Br(-) approximately Cl(-) > gluconate(-). When outwardly rectifying Cl(-) current was induced by hyposmotic extracellular solution, no further stimulatory effect of PGE(2) was seen. Forskolin and dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) mimicked the effect of PGE(2). The PGE(2)-induced Cl(-) current was inhibited by pretreatment with guanosine 5'-O-2-(thiodiphosphate) (GDPbetaS), Rp-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMPS), N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinolinesulfonamide dihydrochloride (H-89), and protein kinase A inhibitors. Even in the absence of nonosteoclastic cells, PGE(2) (1 microM) reduced cell surface area and suppressed motility of osteoclasts, and these effects were abolished by Rp-cAMPS or H-89. PGE(2) is known to exert its effects through four subtypes of PGE receptors (EP1-EP4). EP2 and EP4 agonists (ONO-AE1-259 and ONO-AE1-329, respectively), but not EP1 and EP3 agonists (ONO-DI-004 and ONO-AE-248, respectively), mimicked the electrical and morphological actions of PGE(2) on osteoclasts. Our results show that PGE(2) stimulates rat osteoclast Cl(-) current by activation of a cAMP-dependent pathway through EP2 and, to a lesser degree, EP4 receptors and reduces osteoclast motility. This effect is likely to reduce bone resorption.
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Affiliation(s)
- Fujio Okamoto
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan 814-0193.
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Villa I, Dal Fiume C, Maestroni A, Rubinacci A, Ravasi F, Guidobono F. Human osteoblast-like cell proliferation induced by calcitonin-related peptides involves PKC activity. Am J Physiol Endocrinol Metab 2003; 284:E627-33. [PMID: 12556355 DOI: 10.1152/ajpendo.00307.2002] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The calcitonin peptides [calcitonin (CT), calcitonin gene-related peptide (CGRP), amylin] share many biological actions, including activity on bone cells. In the present study, CT (10(-11) to 10(-9) M) stimulated [(3)H]thymidine incorporation in primary cultures of human osteoblasts (hOB), as already demonstrated for CGRP and amylin. RT-PCR analysis showed that the calcitonin receptor and the calcitonin receptor-like receptor are both expressed in hOB. In these cells, CT (10(-10) M) and amylin (10(-9) M), in contrast to CGRP (10(-8) M), did not increase cAMP production. All three peptides stimulated protein kinase C (PKC) activity. To evaluate PKC involvement in hOB proliferation, cells were incubated with phorbol 12,13-dibutyrate, a stimulator of PKC activity; cell proliferation was increased in a dose-dependent manner (EC(50) = 3.4 x 10(-8) M). Staurosporine (10(-9) M), a PKC inhibitor, blocked phorbol 12,13-dibutyrate-induced PKC activity and cell proliferation. Inhibition of PKC by staurosporine also counteracted the stimulatory effect of CT, CGRP, and amylin on hOB proliferation. From these data, it is deduced that the activation of PKC is important for hOB proliferation and that it is involved in the anabolic effect of CT peptides on bone.
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Affiliation(s)
- I Villa
- Bone Metabolic Unit, Scientific Institute H San Raffaele, 20132 Milan, Italy
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Abstract
Body weight impacts on both bone turnover and bone density, and is therefore an important risk factor for vertebral and hip fractures, ranking in importance alongside that of age. The effect of body weight is probably contributed to by both fat mass and lean mass, although in postmenopausal women fat mass has been more consistently demonstrated to be important. A number of mechanisms for the fat-bone relationship exist and include the effect of soft tissue mass on skeletal loading, the association of fat mass with the secretion of bone-active hormones from the pancreatic beta cell (including insulin, amylin, and preptin), and the secretion of bone-active hormones (e.g., estrogens and leptin) from the adipocyte. These factors alone probably do not fully explain the observed clinical associations, and further study of the actions on bone of novel hormones related to nutrition is an important area of further research. An understanding of this aspect of bone biology may open the way for new treatments of osteoporosis. More immediately, the role of weight maintenance in the prevention of osteoporosis is an important public health message that needs to be more widely appreciated.
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Affiliation(s)
- I R Reid
- Department of Medicine, University of Auckland, New Zealand.
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43
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Abstract
Calcitonin was originally discovered as a hypocalcemic factor synthesized by thyroid parafollicular C cells. Early experiments demonstrated that calcitonin inhibited bone resorption and decreased calcium efflux from isolated cat tibiae and subsequent histologic and culture studies confirmed the osteoclast as its major site of action. Its potent antiresorptive effect and analgesic action have led to its clinical use in treatment of Paget's bone disease, osteoporosis, and hypercalcemia of malignancy. This review surveys the cellular and molecular basis of these physiologic and clinical actions.
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Affiliation(s)
- Angela M Inzerillo
- Mount Sinai Bone Program, Department of Medicine, Mount Sinai School of Medicine, and Bronx Veteran's Affairs Geriatric Research Education and Clinical Center (GRECC), New York, New York 10029, USA
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Abstract
Calcitonin was discovered as a hypocalcemic principal that was initially thought to originate from the parathyroid gland. This view was corrected subsequently, and an origin from the thyroid C cells was documented. The purification and sequencing of various calcitonins soon followed. Calcitonin is a 32-amino-acid-long peptide with an N-terminal disulfide bridge and a C-terminal prolineamide residue. The peptide was shown to potently inhibit bone resorption; however, a direct osteoclastic action of the peptide was confirmed only in the early 1980s. Several osteoclast calcitonin receptors have subsequently been cloned and sequenced. Specific regions of the receptor necessary for ligand binding and intracellular signaling through cyclic AMP and calcium have been identified through systematic deletion mutagenesis and chimeric receptor studies. Calcitonin's potent antiresorptive effect has led to its use in treating Paget's disease of bone, osteoporosis, and hypercalcemia. This review retraces key aspects of the synthesis and structure of calcitonin, its cellular and molecular actions, and its therapeutic uses as they have emerged over the 40 years since its discovery. The review also examines the implications of these findings for future clinical applications as a tribute to early workers to whom credit must be given for creation of an important and expanding field. Notable are the new approaches currently being used to enhance calcitonin action, including novel allosteric activators of the calcitonin receptor, modulation of the release of endogenous calcitonin by calcimimetic agents, as well as the development of oral calcitonins.
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Affiliation(s)
- Mone Zaidi
- Departments of Medicine and Geriatrics, Mount Sinai Bone Program, Mount Sinai School of Medicine, One Gustave Levy Place, Box 1055, New York, NY 10029, USA.
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Cooper GJS. Amylin and Related Proteins: Physiology and Pathophysiology. Compr Physiol 2001. [DOI: 10.1002/cphy.cp070210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Amylin and calcitonin gene-related peptide (CGRP) are homologous 37 amino acid peptides that are found in the circulation. Both peptides belong to the calcitonin family. Similar to calcitonin, amylin and CGRP inhibit osteoclast activity, although they are much less potent than calcitonin. Calcitonin is known to act on the latter stages of osteoclast development, inhibiting the fusion of committed preosteoclasts to form mature multinucleated cells; however, whether or not calcitonin acts earlier in the formation of the precursor osteoclasts is controversial. The question of osteoclast development has never been examined with respect to amylin and CGRP. These issues are addressed in the present study. We studied the effects of calcitonin (salmon and rat), amylin (human and rat), and CGRP (human and rat) in mouse bone marrow cultures stimulated to generate osteoclasts using 1alpha,25-dihydroxyvitamin D3. Calcitonin dose-dependently decreased the numbers of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells as well as TRAP-positive mono-/binucleated cells at concentrations >10(-13) mol/L. Amylin and CGRP showed similar effects at concentrations >10(-9) mol/L. In addition, calcitonin substantially reduced the ratio of TRAP-positive multinucleated to mono-binucleated cells, indicating an effect on fusion of osteoclast precursors. The present data establish that this family of peptides not only acts on mature osteoclasts but also inhibits their development in bone marrow cultures. This activity is shared by amylin and CGRP. The much greater potency of calcitonin than amylin and CGRP is consistent with the action of these peptides being mediated by calcitonin receptors.
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Affiliation(s)
- J Cornish
- Department of Medicine and School of Biological Sciences, University of Auckland, Auckland, New Zealand.
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47
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Abstract
Calcitonin gene-related peptide (CGRP) and amylin are homologous 37-amino-acid peptides which have been demonstrated to have anabolic effects on bone. It is not clear whether these effects are mediated by a common receptor, nor is it known which ligand is the more potent. These questions are addressed in the present study using cultures of fetal rat osteoblasts. CGRP increased cell number when present in a concentration >/=10-9 M, but 10-8 M CGRP was required to stimulate thymidine and phenylalanine incorporation. Amylin was effective on these indices at 100-fold lower concentrations, and its maximal effects were about twice as great as those of CGRP. ED50's for the effects of amylin and CGRP on cell number were 10-12 M and 10-10 M, respectively. There was no additivity between maximal doses of the peptides on these indices. The effects of specific receptor blockers on the maximal stimulation of cell number by these peptides were also studied. The CGRP receptor-blocker, CGRP-(8-37), completely blocked the effect of CGRP at blocker concentrations >/=10-9 M. In contrast, the amylin receptor blocker, amylin-(8-37), completely blocked the effects of CGRP when the blocker was present in concentrations as low as 10-11 M. The KI of CGRP-(8-37) was 2 x 10-10 M and that of amylin-(8-37) was 7 x 10-12 M. In converse experiments studying the blockade of maximal doses of amylin, amylin-(8-37) 10-10 M was effective (KI 1 x 10-10 M), whereas a 100-fold greater concentration of CGRP-(8-37) was necessary to achieve the same effect (KI 6 x 10-9 M). It is concluded that amylin and CGRP probably act through a common receptor to stimulate osteoblast growth, and that this receptor has a higher affinity for amylin than for CGRP.
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Affiliation(s)
- J Cornish
- Department of Medicine, University of Auckland, Auckland, New Zealand
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Cornish J, Callon KE, King AR, Cooper GJ, Reid IR. Systemic administration of amylin increases bone mass, linear growth, and adiposity in adult male mice. Am J Physiol 1998; 275:E694-9. [PMID: 9755090 DOI: 10.1152/ajpendo.1998.275.4.e694] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Amylin is a peptide hormone cosecreted with insulin from the pancreatic beta-cells that can act as an osteoblast mitogen and as an inhibitor of bone resorption. The effects on bone of its systemic administration are uncertain. The present study addresses this question in adult male mice that were given daily subcutaneous injections of amylin (10.5 microgram) or vehicle (n = 20 in each group) for 4 wk. Histomorphometric indices of bone formation increased 30-100% in the amylin-treated group, whereas resorption indices were reduced by approximately 70% (P < 0.005 for all indices). Total bone volume in the proximal tibia was 13.5 +/- 1.4% in control animals and 23.0 +/- 2.0% in those receiving amylin (P = 0.0005). Cortical width, tibial growth plate width, tibial length, body weight, and fat mass were all increased in the amylin-treated group. It is concluded that systemic administration of amylin increases skeletal mass and linear bone growth. This peptide has potential as a therapy for osteoporosis if its bone effects can be dissociated from those on soft tissue mass.
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Affiliation(s)
- J Cornish
- Department of Medicine, University of Auckland, 92019 Auckland, New Zealand
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Cornish J, Callon KE, Lin CQ, Xiao CL, Mulvey TB, Coy DH, Cooper GJ, Reid IR. Dissociation of the effects of amylin on osteoblast proliferation and bone resorption. Am J Physiol 1998; 274:E827-33. [PMID: 9612240 DOI: 10.1152/ajpendo.1998.274.5.e827] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study assesses the structure-activity relationships of the actions of amylin on bone. In fetal rat osteoblasts, only intact amylin and amylin-(1-8) stimulated cell proliferation (half-maximal concentrations 2.0 x 10(-11) and 2.4 x 10(-10) M, respectively). Amylin-(8-37), COOH terminally deamidated amylin, reduced amylin, and reduced amylin-(1-8) (reduction results in cleavage of the disulfide bond) were without agonist effect but acted as antagonists to the effects of both amylin and amylin-(1-8). Calcitonin gene-related peptide-(8-37) also antagonized the effects of amylin and amylin-(1-8) on osteoblasts but was substantially less potent in this regard than amylin-(8-37). In contrast, inhibition of bone resorption in neonatal mouse calvariae only occurred with the intact amylin molecule and was not antagonized by any of these peptides. The rate of catabolism of the peptides in calvarial cultures was not accelerated in comparison with that of intact amylin. This dissociation of the actions of amylin suggests that it acts through two separate receptors, one on the osteoclast (possibly the calcitonin receptor) and a second on the osteoblast.
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Affiliation(s)
- J Cornish
- Department of Medicine, University of Auckland, New Zealand
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Cornish J, Callon KE, Coy DH, Jiang NY, Xiao L, Cooper GJ, Reid IR. Adrenomedullin is a potent stimulator of osteoblastic activity in vitro and in vivo. Am J Physiol 1997; 273:E1113-20. [PMID: 9435526 DOI: 10.1152/ajpendo.1997.273.6.e1113] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Adrenomedullin is a 52-amino acid vasodilator peptide produced in many tissues, including bone. It has 20% sequence identity with amylin, a regulator of osteoblast growth, and circulates in picomolar concentrations. The present study assesses whether adrenomedullin also acts on osteoblasts. At concentrations of 10(-12) M and greater, adrenomedullin produced a dose-dependent increase in cell number and [3H]thymidine incorporation in cultures of fetal rat osteoblasts. This effect was also seen with adrenomedullin-(15-52), -(22-52), and -(27-52), but adrenomedullin-(40-52) was inactive. These effects were lost in the presence of amylin blockers, suggesting they were mediated by the amylin receptor. Adrenomedullin also increased [3H]thymidine incorporation into cultured neonatal mouse calvaria but, unlike amylin, did not reduce bone resorption in this model. Adrenomedullin stimulated phenylalanine incorporation into both isolated osteoblasts and calvaria. When injected daily for 5 days over the calvariae of adult mice, it increased indexes of bone formation two- to threefold (P < 0.0001) and increased mineralized bone area by 14% (P = 0.004). It is concluded that adrenomedullin regulates osteoblast function and that it increases bone mass in vivo. The potential of this family of peptides in the therapy of osteoporosis should be further evaluated.
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Affiliation(s)
- J Cornish
- Department of Medicine, University of Auckland, New Zealand
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