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Rott J, Töpfer ET, Bartosova M, Damgov I, Kolevica A, Heuser A, Shroff R, Zarogiannis SG, Eisenhauer A, Schmitt CP. Calcimimetic AMG-416 induced short-term changes in calcium concentrations and calcium isotope ratios in rats. Biochem Biophys Res Commun 2023; 677:88-92. [PMID: 37562340 DOI: 10.1016/j.bbrc.2023.07.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/19/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023]
Abstract
Calcium (Ca) isotopes (δ44/42Ca) in serum and urine have been suggested as novel sensitive markers of bone calcification. The response of δ44/42Ca to acute changes in Ca homeostasis, has not yet been demonstrated. We measured serum Ca and δ44/42Ca in rats maintained on a standard and a 50% Ca reduced diet for 4 weeks, and after injection of 1 mg/kg of the calcimimetic AMG-416, 24 h prior to sacrifice. AMG-416 decreased serum Ca by a maximum of 0.38 ± 0.10 and 0.53 ± 0.35 mmol/l after 12 and 6 h, respectively, in the standard and low-Ca diet groups (p = 0.0006/0.02), while serum δ44/42Ca did not change over 24 h in both groups. Urinary Ca concentrations were higher 24 h after AMG-416 injection in both groups (p = 0.03/0.06), urine δ44/42Ca was not different compared to the untreated control groups. Our data does not show acute changes in δ44/42Ca in response to a single dose of AMG-416 within 24 h after injection, possibly due to a lack of bone calcification.
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Affiliation(s)
- Jeremy Rott
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Eva Teresa Töpfer
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Maria Bartosova
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Ivan Damgov
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Ana Kolevica
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Alexander Heuser
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Rukshana Shroff
- Renal Unit, University College London Great Ormond Street Hospital and Institute of Child Health, London, UK
| | - Sotirios G Zarogiannis
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Anton Eisenhauer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Claus Peter Schmitt
- Center for Pediatric and Adolescent Medicine, University of Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.
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2
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Boucetta A, Ramtani S, Garzón-Alvarado DA. Both network architecture and micro cracks effects on lacuno-canalicular liquid flow efficiency within the context of multiphysics approach for bone remodeling. J Mech Behav Biomed Mater 2023; 141:105780. [PMID: 36989871 DOI: 10.1016/j.jmbbm.2023.105780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 02/27/2023] [Accepted: 03/12/2023] [Indexed: 03/18/2023]
Abstract
When physical forces are applied to bone, its mechanical adaptive behaviors change according to the microarchitecture configuration. This leads to changes in biological and physical thresholds in the remodeling cell population, involving sensor cells (osteocytes) interacting with each other and changes in osteocyte shape due to variation in lacunar shape. The resulting alterations in fluid flow leads to changes in the membrane electrical potential and shear stress. Eventual creation of microcracks, may lead in turn to modify cell activity. In contrast, the redundancy in the lacuno canalicular network (LCN) interconnectivity maintains partial flow. Our goal was to investigate the role of fluid flow in LCN by proposing a model of electro-mechanical energy spread through inhomogeneous microarchitectures. We focused on mechano-sensitivity to changes in load-induced flow impacted by neighboring micro cracks and quantifying its critical role in changing, velocity, shear stress and orientation of liquid mass transportation from one cell to another. To enhance the concept of intricacy LCN micro-structure to fluid flow, we provide a new combined effects factor considered as osteocytes sensor efficiency. We customized an influence function for each osteocyte, coupling: in one hand, the spatial distribution within remodeling influence areas, conducting a significant fluid spread, leading hydro-dynamic behavior and impacted further by presence of micro cracks and; in other hand, the fluid electro kinetic behavior. As an attempt to fill the limitations stated by many of the recent studies, we reveal in numerical simulation, some results which cannot be measured in vitro/in vivo studies. Numerical calculations were performed in order to evaluate, among many others, how liquid flow conditions changes between lacunas, how the orientation and the magnitude of the governing flow in LCN can regulate osteocytes efficiency. In addition to be regulated by osteocytes, a direct effects of fluid flow are also acting on osteoblast activity. In summary, this new approach considers mechano-sensitivity in relation to liquid flow dynamic and suggests additional pathway for Osseo integration via osteoblast regulation. However, this novel modeling approach may help improve the mapping and design bone scaffolds and/or selection of scaffold implantation regions.
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Affiliation(s)
- Abdelkader Boucetta
- Université Sorbonne Paris Nord, CSPBA-LBPS, UMR CNRS 7244, Inst Galilee, 99 Ave JB Clement, Villetaneuse, France; GE VERNOVA, SS&O-OPS-O&M EMEA Regions, Algiers, Algeria.
| | - Salah Ramtani
- Université Sorbonne Paris Nord, CSPBA-LBPS, UMR CNRS 7244, Inst Galilee, 99 Ave JB Clement, Villetaneuse, France.
| | - Diego A Garzón-Alvarado
- Universidad Nacional de Colombia, Biomimetics Laboratory-Biotechnology Institute, Bogota, 571, Republic of Colombia.
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3
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Bolamperti S, Villa I, Rubinacci A. Bone remodeling: an operational process ensuring survival and bone mechanical competence. Bone Res 2022; 10:48. [PMID: 35851054 PMCID: PMC9293977 DOI: 10.1038/s41413-022-00219-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 05/02/2022] [Accepted: 05/15/2022] [Indexed: 12/12/2022] Open
Abstract
Bone remodeling replaces old and damaged bone with new bone through a sequence of cellular events occurring on the same surface without any change in bone shape. It was initially thought that the basic multicellular unit (BMU) responsible for bone remodeling consists of osteoclasts and osteoblasts functioning through a hierarchical sequence of events organized into distinct stages. However, recent discoveries have indicated that all bone cells participate in BMU formation by interacting both simultaneously and at different differentiation stages with their progenitors, other cells, and bone matrix constituents. Therefore, bone remodeling is currently considered a physiological outcome of continuous cellular operational processes optimized to confer a survival advantage. Bone remodeling defines the primary activities that BMUs need to perform to renew successfully bone structural units. Hence, this review summarizes the current understanding of bone remodeling and future research directions with the aim of providing a clinically relevant biological background with which to identify targets for therapeutic strategies in osteoporosis.
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Affiliation(s)
- Simona Bolamperti
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy
| | - Isabella Villa
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy
| | - Alessandro Rubinacci
- Osteoporosis and Bone and Mineral Metabolism Unit, IRCCS San Raffaele Hospital, Via Olgettina 60, 20132, Milano, Italy.
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Böcker J, Schmitz MT, Mittag U, Jordan J, Rittweger J. Between-Subject and Within-Subject Variaton of Muscle Atrophy and Bone Loss in Response to Experimental Bed Rest. Front Physiol 2022; 12:743876. [PMID: 35273514 PMCID: PMC8902302 DOI: 10.3389/fphys.2021.743876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/30/2021] [Indexed: 01/22/2023] Open
Abstract
To improve quantification of individual responses to bed rest interventions, we analyzed peripheral quantitative computer tomography (pQCT) datasets of the lower leg of 76 participants, who took part in eight different bed rest studies. A newly developed statistical approach differentiated measurement uncertainty UMeas from between-subject-variation (BSV) and within-subject variation (WSV). The results showed that UMeas decreased 59.3% to 80% over the two decades of bed rest studies (p < 0.01), and that it was higher for muscles than for bones. The reduction of UMeas could be explained by improved measurement procedures as well as a higher standardization. The vast majority (82.6%) of the individual responses pci exceeded the 95% confidence interval defined by UMeas, indicating significant and substantial BSV, which was greater for bones than for muscles, especially at the epiphyseal measurement sites. Non-significant to small positive inter-site correlations between bone sites, but very large positive inter-site correlation between muscle sites suggests that substantial WSV exists in the tibia bone, but much less so in the calf musculature. Furthermore, endocortical circumference, an indicator of the individual’s bone geometry could partly explain WSV and BSV. These results demonstrate the existence of substantial BSV bone, and that it is partly driven by WSV, and likely also by physical activity and dietary habits prior to bed rest. In addition, genetic and epigenetic variation could potentially explain BSV, but not WSV. As to the latter, differences of bone characteristics and the bone resorption process could offer an explanation for its existence. The study has also demonstrated the importance of duplicate baseline measurements. Finally, we provide here a rationale for worst case scenarios with partly effective countermeasures in long-term space missions.
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Affiliation(s)
- Jonas Böcker
- Department of Muscle and Bone Metabolism, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
- *Correspondence: Jonas Böcker,
| | - Marie-Therese Schmitz
- Department of Muscle and Bone Metabolism, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
- Institute of Medical Biometry, Informatics and Epidemiology (IMBIE), University Hospital Bonn, Bonn, Germany
| | - Uwe Mittag
- Department of Muscle and Bone Metabolism, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
| | - Jens Jordan
- Chair of Aerospace Medicine, University of Cologne, Cologne, Germany
- German Aerospace Center, Head of Institute of Aerospace Medicine, Cologne, Germany
| | - Jörn Rittweger
- Department of Muscle and Bone Metabolism, German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University Hospital of Cologne, Cologne, Germany
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5
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Dissociation of Bone Resorption and Formation in Spaceflight and Simulated Microgravity: Potential Role of Myokines and Osteokines? Biomedicines 2022; 10:biomedicines10020342. [PMID: 35203551 PMCID: PMC8961781 DOI: 10.3390/biomedicines10020342] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 11/16/2022] Open
Abstract
The dissociation of bone formation and resorption is an important physiological process during spaceflight. It also occurs during local skeletal unloading or immobilization, such as in people with neuromuscular disorders or those who are on bed rest. Under these conditions, the physiological systems of the human body are perturbed down to the cellular level. Through the absence of mechanical stimuli, the musculoskeletal system and, predominantly, the postural skeletal muscles are largely affected. Despite in-flight exercise countermeasures, muscle wasting and bone loss occur, which are associated with spaceflight duration. Nevertheless, countermeasures can be effective, especially by preventing muscle wasting to rescue both postural and dynamic as well as muscle performance. Thus far, it is largely unknown how changes in bone microarchitecture evolve over the long term in the absence of a gravity vector and whether bone loss incurred in space or following the return to the Earth fully recovers or partly persists. In this review, we highlight the different mechanisms and factors that regulate the humoral crosstalk between the muscle and the bone. Further we focus on the interplay between currently known myokines and osteokines and their mutual regulation.
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6
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Abstract
It has previously been reported that in ex vivo planar explants prepared from Xenopus laevis embryos, the intracellular pH (pHi) increases in cells of the dorsal ectoderm from stage 10.5 to 11.5 (i.e. 11-12.5 hpf). It was proposed that such increases (potentially due to H+ being extruded, sequestered, or buffered in some manner), play a role in regulating neural induction. Here, we used an extracellular ion-selective electrode to non-invasively measure H+ fluxes at eight locations around the equatorial circumference of intact X. laevis embryos between stages 9-12 (˜7-13.25 hpf). We showed that at stages 9-11, there was a small H+ efflux recorded from all the measuring positions. At stage 12 there was a small, but significant, increase in the efflux of H+ from most locations, but the efflux from the dorsal side of the embryo was significantly greater than from the other positions. Embryos were also treated from stages 9-12 with bafilomycin A1, to block the activity of the ATP-driven H+ pump. By stage 22 (24 hpf), these embryos displayed retarded development, arresting before the end of gastrulation and therefore did not display the usual anterior and neural structures, which were observed in the solvent-control embryos. In addition, expression of the early neural gene, Zic3, was absent in treated embryos compared with the solvent controls. Together, our new in vivo data corroborated and extended the earlier explant-derived report describing changes in pHi that were suggested to play a role during neural induction in X. laevis embryos.
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Jamieson L, Waters A, Ho KE, Chan HYS, Hung JT, Webb SE, Chan CM, Shipley AM, Williamson JG, Beer J, Angus C, Miller AL. Short-term homeostatic regulation of blood/interstitial fluid Ca 2+ concentration by the scales of anadromous sea trout Salmo trutta L. during smoltification and migration. JOURNAL OF FISH BIOLOGY 2021; 98:17-32. [PMID: 32964432 DOI: 10.1111/jfb.14553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
The elasmoid scales of anadromous sea trout Salmo trutta L. represent a significant internal reservoir of Ca2+ . Although more is known about long-term remodelling of scales in response to calciotropic challenges encountered during smoltification and migration, very little is known about the contribution made by scales to the short-term, minute-to-minute regulation of Ca2+ homeostasis in the extracellular fluid (ECF) during these phases of the life cycle. This gap in the knowledge is partly due to the technical challenges involved in measuring small Ca2+ fluxes around the scales of live fish in real time. Here, this study describes exfoliating, mounting and culturing scales and their resident cells from parr, smolt and adult sea trout from a freshwater environment, as well as from adult sea trout caught in sea or brackish water. All the scales were then examined using an extracellular, non-invasive, surface-scanning Ca2+ -sensitive microelectrode. The authors quantified the Ca2+ fluxes, in the absence of any systemic or local regulators, into and out of scales on both the episquamal and hyposquamal sides under different extracellular calcemic challenges set to mimic a variety of ECF-Ca2+ concentrations. Scales from the life-cycle stages as well as from adult fish taken from sea, brackish or fresh water all showed a consistent efflux or influx of Ca2+ under hypo- or hypercalcemic conditions, respectively. What were considered to be isocalcemic conditions resulted in minimal flux of Ca2+ in either direction, or in the case of adult scales, a consistent but small influx. Indeed, adult scales appeared to display the largest flux densities in either direction. These new data extend the current understanding of the role played by fish scales in the short-term, minute-to-minute homeostatic regulation of ECF-Ca2+ concentration, and are similar to those recently reported from zebrafish Danio rerio scales. This suggests that this short-term regulatory response might be a common feature of teleost scales.
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Affiliation(s)
- Leanna Jamieson
- North Atlantic Fisheries College Marine Centre, University of the Highlands and Islands, Scalloway, UK
| | - Angel Waters
- College of Arts and Sciences, University of New England, Biddeford, Maine, USA
| | - Kaitlyn E Ho
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Harvey Y S Chan
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jacky T Hung
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Sarah E Webb
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ching Man Chan
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Alan M Shipley
- Applicable Electronics, LLC, New Haven, Connecticut, USA
| | | | - Jon Beer
- The Wild Trout Trust, Hampshire, UK
| | - Chevonne Angus
- North Atlantic Fisheries College Marine Centre, University of the Highlands and Islands, Scalloway, UK
| | - Andrew L Miller
- Division of Life Science and State Key Laboratory for Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
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8
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Zelt JG, Svajger BA, Quinn K, Turner ME, Laverty KJ, Shum B, Holden RM, Adams MA. Acute Tissue Mineral Deposition in Response to a Phosphate Pulse in Experimental CKD. J Bone Miner Res 2019; 34:270-281. [PMID: 30216554 DOI: 10.1002/jbmr.3572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 07/29/2018] [Accepted: 08/08/2018] [Indexed: 12/28/2022]
Abstract
Pathogenic accumulation of calcium (Ca) and phosphate (PO4 ) in vasculature is a sentinel of advancing cardiovascular disease in chronic kidney disease (CKD). This study sought to characterize acute distribution patterns of radiolabeled 33 PO4 and 45 Ca in cardiovascular tissues of rats with CKD (0.25% dietary adenine). The disposition of 33 PO4 and 45 Ca was assessed in blood and 36 tissues after a 10-minute intravenous infusion of one of the following: (i) PO4 pulse + tracer 33 PO4 ; (ii) PO4 pulse + tracer 45 Ca; or (iii) saline + tracer 45 Ca in CKD and non-CKD animals. After the infusion, 33 PO4 in blood was elevated (2.3× at 10 minutes, 3.5× at 30 minutes, p < 0.05) in CKD compared with non-CKD. In contrast, there was no difference in clearance of 45 Ca from the blood. Compared with controls, CKD rats had a markedly increased 33 PO4 incorporation in several tissues (skeletal muscle, 7.8×; heart, 5.5×), but accrual was most pronounced in the vasculature (24.8×). There was a significant, but smaller, increase in 45 Ca accrual in the vasculature of CKD rats (1.25×), particularly in the calcified rat, in response to the acute phosphate load. Based on the pattern of tissue uptake of 33 PO4 and 45 Ca, this study revealed that an increase in circulating PO4 is an important stimulus for the accumulation of these minerals in vascular tissue in CKD. This response is further enhanced when vascular calcification is also present. The finding of enhanced vascular mineral deposition in response to an acute PO4 pulse provides evidence of significant tissue-specific susceptibility to calcification. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Jason Ge Zelt
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada.,Molecular Function and Imaging Program, The National Cardiac PET Centre, and the Advanced Heart Disease Program, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute and University of Ottawa, Ottawa, Canada
| | - Bruno A Svajger
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Kieran Quinn
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.,Department of Medicine, University of Toronto, Toronto, Canada
| | - Mandy E Turner
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Kimberly J Laverty
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Bonnie Shum
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Rachel M Holden
- Department of Medicine, Queen's University, Kingston, Canada
| | - Michael A Adams
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
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9
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Zuo H, Sun A, Gao L, Xue W, Deng Y, Wang Y, Zhu S, Ma X, Xin H. Effect of Menopausal Hormone Therapy on Bone Mineral Density in Chinese Women: A 2-Year, Prospective, Open-Label, Randomized-Controlled Trial. Med Sci Monit 2019; 25:819-826. [PMID: 30690446 PMCID: PMC6362761 DOI: 10.12659/msm.912166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background This study was designed to explore the effect of menopausal hormone therapy (MHT) on bone mineral density (BMD) in Chinese women. Material/Methods This was a prospective, open-label, randomized-controlled clinical trial. We randomly assigned 123 postmenopausal women to 3 groups: group A received 0.625 mg conjugated equine estrogen (CEE) plus 100 mg micronized progesterone (MP), group B received 0.3 mg CEE daily plus 100 mg MP, and group C received 0.625 mg CEE daily plus 10 mg dydrogesterone (DHG). All subjects received a 2-year intervention and drugs were given in a continuous sequential pattern. Results Ninety-six patients were followed up. At 1 year, groups A and B gained 2.31% and 1.95% BMD, respectively (P<0.01); at 2 years, groups B and C gained 2.37% and 4.15% BMD (P<0.01) respectively. At 2 years, group A gained 3.28% BMD in the femoral neck and 3.77% BMD in Ward’s triangle (P<0.05). At 1 year, group B lost 2.14% BMD in the trochanter and 1.20% BMD in the total hip (P<0.05); at 2 years, group B lost 1.51% BMD in the total hip (P<0.01). ALP, Ca, P, and Ca/Cr levels were all decreased in the 3 groups (P<0.05). The changes in Cr level at 1 and 2 years were not significant when compared with baseline in all groups (P>0.05). Conclusions Both lower-dose and standard-dose CEE increased lumbar BMD, sustain femoral neck BMD, and Ward’s triangle BMD, while there was a reduced bone turnover rate. Standard-dose CEE combined with MP can increase BMD at these 2 sites. CEE combined with MP is recommended because it has better clinical benefits.
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Affiliation(s)
- Hongling Zuo
- Department of Obstetrics and Gynecology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China (mainland)
| | - Aijun Sun
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Lihong Gao
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Wei Xue
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Yan Deng
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Yanfang Wang
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Bejing, China (mainland)
| | - Shiyang Zhu
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Xiao Ma
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China (mainland)
| | - Hong Xin
- Department of Obstetrics and Gynecology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China (mainland)
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10
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Dedic C, Hung TS, Shipley AM, Maeda A, Gardella T, Miller AL, Divieti Pajevic P, Kunkel JG, Rubinacci A. Calcium fluxes at the bone/plasma interface: Acute effects of parathyroid hormone (PTH) and targeted deletion of PTH/PTH-related peptide (PTHrP) receptor in the osteocytes. Bone 2018; 116:135-143. [PMID: 30053608 PMCID: PMC6158063 DOI: 10.1016/j.bone.2018.07.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/20/2018] [Accepted: 07/24/2018] [Indexed: 01/10/2023]
Abstract
Calcium ion concentration ([Ca2+]) in the systemic extracellular fluid, ECF-[Ca2+], is maintained around a genetically predetermined set-point, which combines the operational level of the kidney and bone/ECF interfaces. The ECF-[Ca2+] is maintained within a narrow oscillation range by the regulatory action of Parathyroid Hormone (PTH), Calcitonin, FGF-23, and 1,25(OH)2D3. This model implies two correction mechanisms, i.e. tubular Ca2+ reabsorption and osteoclast Ca2+ resorption. Although their alterations have an effect on the ECF-[Ca2+] maintenance, they cannot fully account for rapid correction of the continuing perturbations of plasma [Ca2+], which occur daily in life. The existence of Ca2+ fluxes at quiescent bone surfaces fulfills the role of a short-term error correction mechanism in Ca2+ homeostasis. To explore the hypothesis that PTH regulates the cell system responsible for the fast Ca2+ fluxes at the bone/ECF interface, we have performed direct real-time measurements of Ca2+ fluxes at the surface of ex-vivo metatarsal bones maintained in physiological conditions mimicking ECF, and exposed to PTH. To further characterize whether the PTH receptor on osteocytes is a critical component of the minute-to-minute ECF-[Ca2+] regulation, metatarsal bones from mice lacking the PTH receptor in these cells were tested ex vivo for rapid Ca2+ exchange. We performed direct real-time measurements of Ca2+ fluxes and concentration gradients by a scanning ion-selective electrode technique (SIET). To validate ex vivo measurements, we also evaluated acute calcemic response to PTH in vivo in mice lacking PTH receptors in osteocytes vs littermate controls. Our data demonstrated that Ca2+ fluxes at the bone-ECF interface in excised bones as well as acute calcemic response in the short-term were unaffected by PTH exposure and its signaling through its receptor in osteocytes. Rapid minute-to-minute regulation of the ECF-[Ca2+] was found to be independent of PTH actions on osteocytes. Similarly, mice lacking PTH receptor in osteocytes, responded to PTH challenge with similar calcemic increases.
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Affiliation(s)
- Christopher Dedic
- Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Tin Shing Hung
- Division of Life Sciences, State Key Laboratory for Molecular Neuroscience, HKUST, Hong Kong, China
| | | | - Akira Maeda
- Endocrine Unit, Massachusetts General Hospital, Boston, USA; Chugai Pharmaceutical, Japan
| | | | - Andrew L Miller
- Division of Life Sciences, State Key Laboratory for Molecular Neuroscience, HKUST, Hong Kong, China
| | - Paola Divieti Pajevic
- Molecular and Cell Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Joseph G Kunkel
- Pickus Center for Biomedical Research, University of New England, Biddeford, ME, USA
| | - Alessandro Rubinacci
- Bone Metabolism Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy.
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11
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Hohman EE, Hodges JK, Wastney ME, Lachcik PJ, Han CY, Dwyer D, Peacock M, Kostenuik PJ, Weaver CM. Serum calcium concentration is maintained when bone resorption is suppressed by osteoprotegerin in young growing male rats. Bone 2018; 116:162-170. [PMID: 30077758 DOI: 10.1016/j.bone.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 07/26/2018] [Accepted: 08/01/2018] [Indexed: 01/22/2023]
Abstract
Serum calcium (Ca) is maintained in a narrow range through regulation of Ca metabolism in the intestine, kidney, and bone. Calcium is incorporated and resorbed from bone during bone remodeling via cellular processes as well as by exchange. Both routes contribute to calcium homeostasis. To assess the magnitude of bone turnover contribution to calcium homeostasis we labeled bone with a Ca tracer and measured Ca release following stimulation or suppression of bone resorption. Young growing male rats (n = 162) were dosed with 45Ca to label skeletal Ca. After a one-month period to allow the label to incorporate into the skeleton, rats were treated with a bone resorption antagonist (OPG), a bone resorption agonist (RANKL), or vehicle control (PBS). Serum and urine 45Ca and total Ca, and serum TRACP5b (a bone resorption biomarker), were monitored for 45 days following treatment. Tracer data were analyzed by a compartmental model using WinSAAM to quantify dynamic changes in Ca metabolism and identify sites of change following treatment. In RANKL treated rats, both serum 45Ca and serum TRACP5b were increased by >70% due to a 25-fold increase in bone resorption. In OPG treated rats, both serum 45Ca and serum TRACP5b were suppressed by >70% due to a 75% decrease in bone resorption, a 3-fold increase in bone formation, and a 50% increase in absorption. Because TRACP5b and 45Ca responded similarly, we conclude that Ca release from bone into serum occurs mostly via osteoclast-mediated bone resorption. However, because serum Ca concentration did not change with altered resorption in response to either RANKL or OPG treatment, we also conclude that serum Ca concentration under normal dietary conditions in young growing male rats is maintained by processes in addition to cellular bone resorption.
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Affiliation(s)
- Emily E Hohman
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Joanna K Hodges
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Meryl E Wastney
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Pamela J Lachcik
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | - Chun-Ya Han
- Metabolic Disorders Research, Amgen, Thousand Oaks, CA, USA
| | - Denise Dwyer
- Metabolic Disorders Research, Amgen, Thousand Oaks, CA, USA
| | - Munro Peacock
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Paul J Kostenuik
- Phylon Pharma Services, Newbury Park, CA, USA; University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Connie M Weaver
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA.
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Arcidiacono T, Simonini M, Lanzani C, Citterio L, Salvi E, Barlassina C, Spotti D, Cusi D, Manunta P, Vezzoli G. Claudin-14 Gene Polymorphisms and Urine Calcium Excretion. Clin J Am Soc Nephrol 2018; 13:1542-1549. [PMID: 30232134 PMCID: PMC6218816 DOI: 10.2215/cjn.01770218] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/03/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND OBJECTIVES Claudin-16 and -19 are proteins forming pores for the paracellular reabsorption of divalent cations in the ascending limb of Henle loop; conversely, claudin-14 decreases ion permeability of these pores. Single-nucleotide polymorphisms in gene coding for claudin-14 were associated with kidney stones and calcium excretion. This study aimed to explore the association of claudin-14, claudin-16, and claudin-19 single-nucleotide polymorphisms with calcium excretion. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We performed a retrospective observational study of 393 patients with hypertension who were naïve to antihypertensive drugs, in whom we measured 24-hour urine calcium excretion; history of kidney stones was ascertained by interview; 370 of these patients underwent an intravenous 0.9% sodium chloride infusion (2 L in 2 hours) to evaluate the response of calcium excretion in three different 2-hour urine samples collected before, during, and after saline infusion. Genotypes of claudin-14, claudin-16, and claudin-19 were obtained from data of a previous genome-wide association study in the same patients. RESULTS Thirty-one single-nucleotide polymorphisms of the 3' region of the claudin-14 gene were significantly associated with 24-hour calcium excretion and calcium excretion after saline infusion. The most significant associated single-nucleotide polymorphism was rs219755 (24-hour calcium excretion in GG, 225±124 mg/24 hours; 24-hour calcium excretion in GA, 194±100 mg/24 hours; 24-hour calcium excretion in AA, 124±73 mg/24 hours; P<0.001; calcium excretion during saline infusion in GG, 30±21 mg/2 hours; calcium excretion during saline infusion in GA, 29±18 mg/2 hours; calcium excretion during saline infusion in AA, 17±11 mg/2 hours; P=0.03). No significant associations were found among claudin-16 and claudin-19 single-nucleotide polymorphisms and calcium excretion and between claudin-14, claudin-16, and claudin-19 single-nucleotide polymorphisms and stones. Bioinformatic analysis showed that one single-nucleotide polymorphism at claudin-14 among those associated with calcium excretion may potentially influence splicing of transcript. CONCLUSIONS Claudin-14 genotype at the 3' region is associated with calcium excretion in 24-hour urine and after the calciuretic stimulus of saline infusion.
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Affiliation(s)
- Teresa Arcidiacono
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Marco Simonini
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Chiara Lanzani
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Lorena Citterio
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Erika Salvi
- Department of Health Sciences, University of Milan, Milan, Italy; and
- Filarete Foundation, Milan, Italy
| | - Cristina Barlassina
- Department of Health Sciences, University of Milan, Milan, Italy; and
- Filarete Foundation, Milan, Italy
| | - Donatella Spotti
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Daniele Cusi
- Department of Health Sciences, University of Milan, Milan, Italy; and
- Filarete Foundation, Milan, Italy
| | - Paolo Manunta
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
| | - Giuseppe Vezzoli
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, Genomics of Renal Diseases and Hypertension Unit, Vita Salute San Raffaele University, Milan, Italy
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13
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Pirosa A, Gottardi R, Alexander PG, Tuan RS. Engineering in-vitro stem cell-based vascularized bone models for drug screening and predictive toxicology. Stem Cell Res Ther 2018; 9:112. [PMID: 29678192 PMCID: PMC5910611 DOI: 10.1186/s13287-018-0847-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The production of veritable in-vitro models of bone tissue is essential to understand the biology of bone and its surrounding environment, to analyze the pathogenesis of bone diseases (e.g., osteoporosis, osteoarthritis, osteomyelitis, etc.), to develop effective therapeutic drug screening, and to test potential therapeutic strategies. Dysregulated interactions between vasculature and bone cells are often related to the aforementioned pathologies, underscoring the need for a bone model that contains engineered vasculature. Due to ethical restraints and limited prediction power of animal models, human stem cell-based tissue engineering has gained increasing relevance as a candidate approach to overcome the limitations of animals and to serve as preclinical models for drug testing. Since bone is a highly vascularized tissue, the concomitant development of vasculature and mineralized matrix requires a synergistic interaction between osteogenic and endothelial precursors. A number of experimental approaches have been used to achieve this goal, such as the combination of angiogenic factors and three-dimensional scaffolds, prevascularization strategies, and coculture systems. In this review, we present an overview of the current models and approaches to generate in-vitro stem cell-based vascularized bone, with emphasis on the main challenges of vasculature engineering. These challenges are related to the choice of biomaterials, scaffold fabrication techniques, and cells, as well as the type of culturing conditions required, and specifically the application of dynamic culture systems using bioreactors.
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Affiliation(s)
- Alessandro Pirosa
- Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219 USA
| | - Riccardo Gottardi
- Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219 USA
- Ri.MED Foundation, Via Bandiera 11, Palermo, 90133 Italy
| | - Peter G. Alexander
- Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219 USA
| | - Rocky S. Tuan
- Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, 450 Technology Drive, Pittsburgh, PA 15219 USA
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14
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Granjon D, Bonny O, Edwards A. Coupling between phosphate and calcium homeostasis: a mathematical model. Am J Physiol Renal Physiol 2017; 313:F1181-F1199. [PMID: 28747359 DOI: 10.1152/ajprenal.00271.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/19/2017] [Accepted: 07/19/2017] [Indexed: 12/18/2022] Open
Abstract
We developed a mathematical model of calcium (Ca) and phosphate (PO4) homeostasis in the rat to elucidate the hormonal mechanisms that underlie the regulation of Ca and PO4 balance. The model represents the exchanges of Ca and PO4 between the intestine, plasma, kidneys, bone, and the intracellular compartment, and the formation of Ca-PO4-fetuin-A complexes. It accounts for the regulation of these fluxes by parathyroid hormone (PTH), vitamin D3, fibroblast growth factor 23, and Ca2+-sensing receptors. Our results suggest that the Ca and PO4 homeostatic systems are robust enough to handle small perturbations in the production rate of either PTH or vitamin D3 The model predicts that large perturbations in PTH or vitamin D3 synthesis have a greater impact on the plasma concentration of Ca2+ ([Ca2+]p) than on that of PO4 ([PO4]p); due to negative feedback loops, [PO4]p does not consistently increase when the production rate of PTH or vitamin D3 is decreased. Our results also suggest that, following a large PO4 infusion, the rapidly exchangeable pool in bone acts as a fast, transient storage PO4 compartment (on the order of minutes), whereas the intracellular pool is able to store greater amounts of PO4 over several hours. Moreover, a large PO4 infusion rapidly lowers [Ca2+]p owing to the formation of CaPO4 complexes. A large Ca infusion, however, has a small impact on [PO4]p, since a significant fraction of Ca binds to albumin. This mathematical model is the first to include all major regulatory factors of Ca and PO4 homeostasis.
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Affiliation(s)
- David Granjon
- Sorbonne Universités, UPMC University of Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France.,Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Aurélie Edwards
- Sorbonne Universités, UPMC University of Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; .,Department of Biomedical Engineering, Boston University, Boston, Massachusetts
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15
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Xiang B, Liu Y, Xie L, Zhao Q, Zhang L, Gan X, Yu H. The osteoclasts attach to the bone surface where the extracellular calcium concentration decreases. Cell Biochem Biophys 2016; 74:553-558. [PMID: 27718044 DOI: 10.1007/s12013-016-0757-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 08/12/2016] [Indexed: 02/05/2023]
Abstract
Osteoclasts demineralize and resorb bone once they attach to its surface. However, it's still unclear how the osteoclasts choose the specific sites for their attachments. It is postulated in this article that the decreased extracellular free ionized calcium concentration (Ca2+[e]) can provide a microenvironment for osteoclasts to recognize and then initiate the attachment process. The osteoclasts initially attach to the bone surface via integrating its integrin αvβ3 and RGD containing ligands in bone matrix. Through the interaction with RGD-containing ligand, the integrin αvβ3 forms carboxylate oxygen noncovalent, which is further stabilized by accompanied electrostatic interaction between the Ca2+ and the β3 subunit. There are two types of cation-binding sites on the β3 subunit: the high affinity Ca2+ binding site ("LC" site) that activates the osteoclasts by promoting the combination; the low affinity Ca2+ binding site ("I" site, also named ADMIDAS) that deactivates the osteoclasts by dissociating the combination and it can override the "LC" site's positive effect on osteoclasts when necessary. Normally the Ca2+ concentration of bone extracellular fluid is maintained within a normal range by osteocytes, keeping the "I" sites activated. When the osteocytes' function stalls and the ambient Ca2+ concentration falls below the affinity discrimination threshold between the "I" site and the "LC" site, the "LC" site's promoting function starts to out compete the "I" site in its inhibitory effect, in which case the inactive integrin αvβ3 turns into an extended active form and the osteoclasts start to attach, signifying the initiation of bone resorption.
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Affiliation(s)
- Bilu Xiang
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Yang Liu
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Lu Xie
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Qian Zhao
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Ling Zhang
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Xueqi Gan
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China
| | - Haiyang Yu
- The State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Chengdu, China.
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16
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Cosso R, Falchetti A. Vitamin K and bone metabolism: the myth and the truth. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2016. [DOI: 10.1080/23808993.2016.1174061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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17
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Alghadir AH, Gabr SA, Al-Eisa ES, Alghadir MH. Correlation between bone mineral density and serum trace elements in response to supervised aerobic training in older adults. Clin Interv Aging 2016; 11:265-73. [PMID: 27013870 PMCID: PMC4778779 DOI: 10.2147/cia.s100566] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Background Life style and physical activity play a pivotal role in prevention and treatment of osteoporosis. The mechanism for better bone metabolism and improvement of physical disorders is not clear yet. Trace minerals such as Ca, Mn, Cu, and Zn are essential precursors for most vital biological process, especially those of bone health. Objective The main target of this study was evaluating the effective role of supervised aerobic exercise for 1 hour/day, 3 days/week for 12 weeks in the functions of trace elements in bone health through measuring bone mineral density (BMD), osteoporosis (T-score), bone markers, and trace element concentrations in healthy subjects aged 30–60 years with age average of 41.2±4.9. Methods A total of 100 healthy subjects (47 males, 53 females; age range 30–60 years) were recruited for this study. Based on dual-energy x-ray absorptiometry (DEXA) scan analysis, the participants were classified into three groups: normal (n=30), osteopenic (n=40), and osteoporotic (n=30). Following, 12 weeks of moderate aerobic exercise, bone-specific alkaline phosphatase (BAP), BMD, T-score, and trace elements such as Ca, Mn, Cu, and Zn were assessed at baseline and post-intervention. Results Significant improvement in serum BAP level, T-score, and BMD were observed in all participants following 12 weeks of moderate exercise. Participants with osteopenia and osteoporosis showed significant increase in serum Ca and Mn, along with decrease in serum Cu and Zn levels following 12 weeks of aerobic training. In control group, the improvements in serum trace elements and body mass index were significantly linked with the enhancement in the levels of BAP, BMD hip, and BMD spine. These results supported the preventive effects of moderate exercise in healthy subjects against osteoporosis. In both sexes, the changes in serum trace elements significantly correlated (P<0.05) with the improvement in BAP, BMD hip, BMD spine, and body mass index in all groups. Conclusion The observed changes in the levels of Ca, Mn, Cu, and Zn were shown to be positively correlated with improved bone mass density among control and osteoporosis subjects of both sexes. These results demonstrate that aerobic exercise of moderate intensity might protect bone and cartilage by regulation of body trace elements which are involved in the biosynthesis of bone matrix structures and inhibition of bone resorption process via a proposed anti-free radical mechanism.
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Affiliation(s)
- Ahmad H Alghadir
- Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Sami A Gabr
- Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia; Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Einas S Al-Eisa
- Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Muaz H Alghadir
- Department of Orthopedics, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
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18
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Luxardi G, Reid B, Ferreira F, Maillard P, Zhao M. Measurement of extracellular ion fluxes using the ion-selective self-referencing microelectrode technique. J Vis Exp 2015:e52782. [PMID: 25993490 DOI: 10.3791/52782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cells from animals, plants and single cells are enclosed by a barrier called the cell membrane that separates the cytoplasm from the outside. Cell layers such as epithelia also form a barrier that separates the inside from the outside or different compartments of multicellular organisms. A key feature of these barriers is the differential distribution of ions across cell membranes or cell layers. Two properties allow this distribution: 1) membranes and epithelia display selective permeability to specific ions; 2) ions are transported through pumps across cell membranes and cell layers. These properties play crucial roles in maintaining tissue physiology and act as signaling cues after damage, during repair, or under pathological condition. The ion-selective self-referencing microelectrode allows measurements of specific fluxes of ions such as calcium, potassium or sodium at single cell and tissue levels. The microelectrode contains an ionophore cocktail which is selectively permeable to a specific ion. The internal filling solution contains a set concentration of the ion of interest. The electric potential of the microelectrode is determined by the outside concentration of the ion. As the ion concentration varies, the potential of the microelectrode changes as a function of the log of the ion activity. When moved back and forth near a source or sink of the ion (i.e. in a concentration gradient due to ion flux) the microelectrode potential fluctuates at an amplitude proportional to the ion flux/gradient. The amplifier amplifies the microelectrode signal and the output is recorded on computer. The ion flux can then be calculated by Fick's law of diffusion using the electrode potential fluctuation, the excursion of microelectrode, and other parameters such as the specific ion mobility. In this paper, we describe in detail the methodology to measure extracellular ion fluxes using the ion-selective self-referencing microelectrode and present some representative results.
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Affiliation(s)
- Guillaume Luxardi
- Department of Dermatology, Institute for Regenerative Cures, University of California, Davis;
| | - Brian Reid
- Department of Dermatology, Institute for Regenerative Cures, University of California, Davis
| | - Fernando Ferreira
- Department of Dermatology, Institute for Regenerative Cures, University of California, Davis; Departamento de Biologia, Centro de Biologia Molecular e Ambiental, Universidade do Minho
| | - Pauline Maillard
- Department of Neurology and Center for Neuroscience, University of California, Davis Imaging of Dementia and Aging Laboratory
| | - Min Zhao
- Department of Dermatology, Institute for Regenerative Cures, University of California, Davis; Department of Ophthalmology, Institute for Regenerative Cures, University of California, Davis
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19
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Reid B, Zhao M. Ion-selective self-referencing probes for measuring specific ion flux. Commun Integr Biol 2014. [DOI: 10.4161/cib.16182] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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20
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Alghadir AH, Aly FA, Gabr SA. Effect of Moderate Aerobic Training on Bone Metabolism Indices among Adult Humans. Pak J Med Sci 2014; 30:840-4. [PMID: 25097528 PMCID: PMC4121709 DOI: 10.12669/pjms.304.4624] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 03/27/2014] [Accepted: 04/02/2014] [Indexed: 11/15/2022] Open
Abstract
Objective: This study assessed the osteogenic effect (T-Score) and changes in bone markers in healthy subjects by 12-weeks of aerobic training. Methods: Total 65 healthy subjects (36 males, 29 females), their age ranged between 30 and 60 years with normal body mass index, were recruited to participate in this study and they were selected among healthy subjects who do not have any metabolic disorders and were not receiving any medication that could affect the bone turnover. Standardized physical examination and collection of serum samples were performed at base line and after 12 weeks of moderate aerobic training to measure bone formation markers (osteocalcin (OC) and bone specific alkaline Phosphatase (BAP) and bone resorption marker Deoxypyridinoline (DPD), and serum calcium. Each subject participated in exercise training program for 12 weeks, three times per week. Results: The results showed that the 12 weeks of moderate aerobic training produced a significant improvement in all bone metabolism indices including Serum bone-specific alkaline phosphatase, serum osteocalcin, serum free Calcium and bone mineral density among all subjects. Conclusion: Moderate intensity of aerobic training exerts significant positive effects on bone formation marker and bone density associated with a significant decrease in the rate of bone resorption that could assist in preventing or decelerating osteoporosis.
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Affiliation(s)
- Ahmad H Alghadir
- Ahmad H. Alghadir, Department of Rehabilitation Sciences, College of Applied Medical Sciences, Rehabilitation Research Chair King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Farag A Aly
- Farag A. Aly, Faculty of Physical Therapy, Cairo University, Cairo, Egypt. Rehabilitation Research Chair King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Sami A Gabr
- Sami A. Gabr, Department of Anatomy, Faculty of Medicine, Mansoura University, Rehabilitation Research Chair King Saud University, Riyadh, Kingdom of Saudi Arabia. Egypt
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Abstract
The imbalance between bone formation and resorption during bone remodeling has been documented to be a major factor in the pathogenesis of osteoporosis. Recent evidence suggests a significant role for the tight junction proteins, Claudins (Cldns), in the regulation of bone remodeling processes. In terms of function, whereas Cldns act "canonically" as key determinants of paracellular permeability, there is considerable recent evidence to suggest that Cldns also participate in cell signaling, ie, a "noncanonical function". To this end, Cldns have been shown to regulate cell proliferation, differentiation, and gene expression in a variety of cell types. The present review will discuss Cldns' structure, their expression profile, regulation of expression, and their canonical and non- canonical functions in general with special emphasis on bone cells. In order to shed light on the noncanonical functions of Cldns in bone, we will highlight the role of Cldn-18 in regulating bone resorption and osteoclast differentiation. Collectively, we hope to provide a framework for guiding future research on understanding how Cldns modulate osteoblast and osteoclast function and overall bone homeostasis. Such studies should provide valuable insights into the pathogenesis of osteoporosis, and may highlight Cldns as novel targets for the diagnosis and therapeutic management of osteoporosis.
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Affiliation(s)
- Fatima Z Alshbool
- Musculoskeletal Disease Center (F.Z.A., S.M.), Jerry L. Pettis VA Medical Center, Loma Linda, CA 92357; Departments of Medicine (S.M.), Biochemistry (S.M.), Physiology (S.M.), and Pharmacology (F.Z.A., S.M.), Loma Linda University, Loma Linda, California 92354
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22
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Whyte MP, Leelawattana R, Reinus WR, Yang C, Mumm S, Novack DV. Acute severe hypercalcemia after traumatic fractures and immobilization in hypophosphatasia complicated by chronic renal failure. J Clin Endocrinol Metab 2013; 98:4606-12. [PMID: 24064686 PMCID: PMC6287393 DOI: 10.1210/jc.2013-1811] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Hypophosphatasia (HPP) features deficient activity of the "tissue-nonspecific" isoenzyme of alkaline phosphatase (TNSALP) due to loss-of-function mutation(s) within the TNSALP gene. Consequently, inorganic pyrophosphate, a TNSALP substrate and inhibitor of mineralization, accumulates extracellularly. This can cause rickets or osteomalacia. OBJECTIVE We report a 55-year-old man with HPP and chronic renal failure (CRF) requiring hemodialysis who developed severe hypercalcemia acutely after traumatic fractures and immobilization. He manifested HPP in childhood and in middle age received hemodialysis for CRF attributed to hypertension and anti-inflammatory medication. He took 2 g of calcium carbonate orally each day to bind dietary phosphorus, but never aluminum hydroxide or any form of vitamin D. Pretrauma serum levels of calcium spanned 8.4-10.7 mg/dL (normal [Nl], 8.6-10.3), inorganic phosphate 5.8-6.4 mg/dL (Nl, 2.5-4.5), and PTH 63-75 pg/mL (Nl, 10-55). RESULTS Rapid succession falls fractured multiple major bones. Six hours later, he became confused. Serum calcium was 14.9 mg/dL, ionized calcium was 7.4 mg/dL (Nl, 4.5-5.1), and PTH was 16 pg/mL. Hemodialysis quickly corrected his hypercalcemia and confusion. Low serum alkaline phosphatase persisted, and follow-up skeletal histopathology showed that his osteomalacia was severe. CONCLUSION Hemodialysis does not heal the skeletal disease of HPP. During sudden fracture immobilization in HPP, sufficient calcium can emerge from bone, perhaps from a rapidly exchangeable calcium pool, to cause acute severe hypercalcemia if the kidneys cannot compensate for the mineral efflux. Hence, we worry that acute hypercalcemia might accompany sudden immobilization in CRF patients without HPP if they have adynamic bone disease.
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Affiliation(s)
- Michael P Whyte
- MD, Shriners Hospital for Children, 2001 South Lindbergh Boulevard, St Louis, MO 63131.
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Lemaire T, Kaiser J, Naili S, Sansalone V. Textural versus electrostatic exclusion-enrichment effects in the effective chemical transport within the cortical bone: a numerical investigation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2013; 29:1223-1242. [PMID: 23804591 DOI: 10.1002/cnm.2571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
Interstitial fluid within bone tissue is known to govern the remodelling signals' expression. Bone fluid flow is generated by skeleton deformation during the daily activities. Due to the presence of charged surfaces in the bone porous matrix, the electrochemical phenomena occurring in the vicinity of mechanosensitive bone cells, the osteocytes, are key elements in the cellular communication. In this study, a multiscale model of interstitial fluid transport within bone tissues is proposed. Based on an asymptotic homogenization method, our modelling takes into account the physicochemical properties of bone tissue. Thanks to this multiphysical approach, the transport of nutrients and waste between the blood vessels and the bone cells can be quantified to better understand the mechanotransduction of bone remodelling. In particular, it is shown that the electrochemical tortuosity may have stronger implications in the mass transport within the bone than the purely morphological one.
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Affiliation(s)
- T Lemaire
- Université Paris Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 61 Avenue du Général de Gaulle, 94010 Créteil, France
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Martelli D, Luppi M, Cerri M, Tupone D, Perez E, Zamboni G, Amici R. Waking and sleeping following water deprivation in the rat. PLoS One 2012; 7:e46116. [PMID: 23029406 PMCID: PMC3454381 DOI: 10.1371/journal.pone.0046116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 08/28/2012] [Indexed: 11/30/2022] Open
Abstract
Wake-sleep (W-S) states are affected by thermoregulation. In particular, REM sleep (REMS) is reduced in homeotherms under a thermal load, due to an impairment of hypothalamic regulation of body temperature. The aim of this work was to assess whether osmoregulation, which is regulated at a hypothalamic level, but, unlike thermoregulation, is maintained across the different W-S states, could influence W-S occurrence. Sprague-Dawley rats, kept at an ambient temperature of 24°C and under a 12 h∶12 h light-dark cycle, were exposed to a prolonged osmotic challenge of three days of water deprivation (WD) and two days of recovery in which free access to water was restored. Two sets of parameters were determined in order to assess: i) the maintenance of osmotic homeostasis (water and food consumption; changes in body weight and fluid composition); ii) the effects of the osmotic challenge on behavioral states (hypothalamic temperature (Thy), motor activity, and W-S states). The first set of parameters changed in WD as expected and control levels were restored on the second day of recovery, with the exception of urinary Ca++ that almost disappeared in WD, and increased to a high level in recovery. As far as the second set is concerned, WD was characterized by the maintenance of the daily oscillation of Thy and by a decrease in activity during the dark periods. Changes in W-S states were small and mainly confined to the dark period: i) REMS slightly decreased at the end of WD and increased in recovery; ii) non-REM sleep (NREMS) increased in both WD and recovery, but EEG delta power, a sign of NREMS intensity, decreased in WD and increased in recovery. Our data suggest that osmoregulation interferes with the regulation of W-S states to a much lesser extent than thermoregulation.
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Affiliation(s)
- Davide Martelli
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- Systems Neurophysiology Division, Florey Neuroscience Institutes, University of Melbourne, Melbourne, Australia
| | - Marco Luppi
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Matteo Cerri
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Domenico Tupone
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- Oregon National Primate Research Center, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Emanuele Perez
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Giovanni Zamboni
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
- * E-mail:
| | - Roberto Amici
- Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna, Bologna, Italy
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Interstitial fluid flow within bone canaliculi and electro-chemo-mechanical features of the canalicular milieu: a multi-parametric sensitivity analysis. Biomech Model Mechanobiol 2012; 12:533-53. [PMID: 22869342 DOI: 10.1007/s10237-012-0422-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 07/16/2012] [Indexed: 10/28/2022]
Abstract
Canalicular fluid flow is acknowledged to play a major role in bone functioning, allowing bone cells' metabolism and activity and providing an efficient way for cell-to-cell communication. Bone canaliculi are small canals running through the bone solid matrix, hosting osteocyte's dendrites, and saturated by an interstitial fluid rich in ions. Because of the small size of these canals (few hundred nanometers in diameter), fluid flow is coupled with electrochemical phenomena. In our previous works, we developed a multi-scale model accounting for coupled hydraulic and chemical transport in the canalicular network. Unfortunately, most of the physical and geometrical information required by the model is hardly accessible by nowadays experimental techniques. The goal of this study was to numerically assess the influence of the physical and material parameters involved in the canalicular fluid flow. The focus was set on the electro-chemo-mechanical features of the canalicular milieu, hopefully covering any in vivo scenario. Two main results were obtained. First, the most relevant parameters affecting the canalicular fluid flow were identified and their effects quantified. Second, these findings were given a larger scope to cover also scenarios not considered in this study. Therefore, this study gives insight into the potential interactions between electrochemistry and mechanics in bone and provides the rational for further theoretical and experimental investigations.
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Kaiser J, Lemaire T, Naili S, Sansalone V, Komarova S. Do calcium fluxes within cortical bone affect osteocyte mechanosensitivity? J Theor Biol 2012; 303:75-86. [DOI: 10.1016/j.jtbi.2012.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 01/10/2012] [Accepted: 03/01/2012] [Indexed: 01/15/2023]
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27
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Qing H, Ardeshirpour L, Pajevic PD, Dusevich V, Jähn K, Kato S, Wysolmerski J, Bonewald LF. Demonstration of osteocytic perilacunar/canalicular remodeling in mice during lactation. J Bone Miner Res 2012; 27:1018-29. [PMID: 22308018 PMCID: PMC3770147 DOI: 10.1002/jbmr.1567] [Citation(s) in RCA: 338] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Osteoclasts are thought to be solely responsible for the removal of bone matrix. However, we show here that osteocytes can also remove bone matrix by reversibly remodeling their perilacunar/canalicular matrix during the reproductive cycle. In contrast, no osteocytic remodeling was observed with experimental unloading despite similar degrees of bone loss. Gene array analysis of osteocytes from lactating animals revealed an elevation of genes known to be utilized by osteoclasts to remove bone, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, that returned to virgin levels upon weaning. Infusion of parathyroid hormone-related peptide (PTHrP), known to be elevated during lactation, induced TRAP activity and cathepsin K expression in osteocytes concurrent with osteocytic remodeling. Conversely, animals lacking the parathyroid hormone type 1 receptor (PTHR1) in osteocytes failed to express TRAP or cathepsin K or to remodel their osteocyte perilacunar matrix during lactation. These studies show that osteocytes remove mineralized matrix through molecular mechanisms similar to those utilized by osteoclasts.
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Affiliation(s)
- Hai Qing
- School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Laleh Ardeshirpour
- Section of Pediatric Endocrinology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Paola Divieti Pajevic
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School Boston, MA 02114, USA
| | - Vladimir Dusevich
- School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Katharina Jähn
- School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
| | - Shigeaki Kato
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
| | - John Wysolmerski
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Lynda F. Bonewald
- School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, 64108, USA
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28
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Reid B, Zhao M. Ion-selective self-referencing probes for measuring specific ion flux. Commun Integr Biol 2011; 4:524-7. [PMID: 22046453 PMCID: PMC3204119 DOI: 10.4161/cib.4.5.16182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 04/27/2011] [Indexed: 11/19/2022] Open
Abstract
The metal vibrating probe developed in the 1970s to measure electric current is sensitive down to the micro-Amp range, but detects only net current due to flow of multiple ions and is too large to measure from single cells. Electrophysiological techniques which use glass microelectrodes such as voltage clamping can be used on single cells but are also non-specific. Ion-selective probes are glass microelectrodes containing at their tip a small amount of ionophore permeable to a particular ion. The electrode is therefore sensitive to changes in concentration of this ion. If the probe tip is moved at low frequency between two points in a concentration gradient of this ion then the electrochemical potential of the solution inside the electrode fluctuates in proportion to the size of the ion gradient. This fluctuation is amplified and recorded and is used to calculate the actual ion flux using Fick's law of diffusion. In this mini-review we describe the technique of ion-selective self-referencing microelectrodes to measure specific ion fluxes. We discuss the development of the technique and describe in detail the methodology and present some representative results.
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Affiliation(s)
- Brian Reid
- Department of Dermatology; University of California; Davis, CA USA
| | - Min Zhao
- Department of Dermatology; University of California; Davis, CA USA
- Department of Ophthalmology; University of California; Davis, CA USA
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29
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Kaiser J, Lemaire T, Naili S, Komarova SV, Sansalone V. Calcium fluxes within cortical bone fluid may affect osteocyte mechanosensitivity. Comput Methods Biomech Biomed Engin 2011. [DOI: 10.1080/10255842.2011.593937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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30
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Taryba M, Lamaka S, Snihirova D, Ferreira M, Montemor M, Wijting W, Toews S, Grundmeier G. The combined use of scanning vibrating electrode technique and micro-potentiometry to assess the self-repair processes in defects on “smart” coatings applied to galvanized steel. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.02.048] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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31
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Abstract
Calcium balance is an overall assessment of the net calcium taken in minus the net calcium taken out. It can only be assessed when patients are in steady state and requires complicated isotope methods that can simultaneously assess intestinal absorption and endogenous secretion, urinary and stool excretion, bone calcium uptake and removal, and dialysate calcium removal. By virtue of the need for steady state, formal balance studies cannot be accurately carried out in patients on dialysis. However, many of the components of calcium balance have been assessed. Importantly, because 99% of calcium is in bone, studies must accurately assess both the rapidly exchangeable calcium from the bone surface and the net bone calcium balance that results from the difference in bone formation minus resorption. While it is tempting to adjust the dialysate calcium concentration to correct the net positive calcium balance that is likely present in patients who receive calcium-based phosphate binders, the reality is that the highly variable, yet important, role of bone cannot be easily assessed at the bedside. Thus, it is best to prevent the calcium overload in the first place by avoiding high-dose calcium-based phosphate binders and optimizing bone remodeling.
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Affiliation(s)
- Sharon M Moe
- Departments of Medicine, Anatomy & Cell Biology, Indiana University School of Medicine, Roudebush Veterans Administration Hospital, Indianapolis, Indiana 46260, USA.
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32
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Henriksen K, Bollerslev J, Everts V, Karsdal MA. Osteoclast activity and subtypes as a function of physiology and pathology--implications for future treatments of osteoporosis. Endocr Rev 2011; 32:31-63. [PMID: 20851921 DOI: 10.1210/er.2010-0006] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Osteoclasts have traditionally been associated exclusively with catabolic functions that are a prerequisite for bone resorption. However, emerging data suggest that osteoclasts also carry out functions that are important for optimal bone formation and bone quality. Moreover, recent findings indicate that osteoclasts have different subtypes depending on their location, genotype, and possibly in response to drug intervention. The aim of the current review is to describe the subtypes of osteoclasts in four different settings: 1) physiological, in relation to turnover of different bone types; 2) pathological, as exemplified by monogenomic disorders; 3) pathological, as identified by different disorders; and 4) in drug-induced situations. The profiles of these subtypes strongly suggest that these osteoclasts belong to a heterogeneous cell population, namely, a diverse macrophage-associated cell type with bone catabolic and anabolic functions that are dependent on both local and systemic parameters. Further insight into these osteoclast subtypes may be important for understanding cell-cell communication in the bone microenvironment, treatment effects, and ultimately bone quality.
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Affiliation(s)
- K Henriksen
- Nordic Bioscience A/S, Herlev Hovedgade 207, DK-2730 Herlev, Denmark.
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Peterson MC, Riggs MM. A physiologically based mathematical model of integrated calcium homeostasis and bone remodeling. Bone 2010; 46:49-63. [PMID: 19732857 DOI: 10.1016/j.bone.2009.08.053] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 08/24/2009] [Accepted: 08/26/2009] [Indexed: 12/30/2022]
Abstract
Bone biology is physiologically complex and intimately linked to calcium homeostasis. The literature provides a wealth of qualitative and/or quantitative descriptions of cellular mechanisms, bone dynamics, associated organ dynamics, related disease sequela, and results of therapeutic interventions. We present a physiologically based mathematical model of integrated calcium homeostasis and bone biology constructed from literature data. The model includes relevant cellular aspects with major controlling mechanisms for bone remodeling and calcium homeostasis and appropriately describes a broad range of clinical and therapeutic conditions. These include changes in plasma parathyroid hormone (PTH), calcitriol, calcium and phosphate (PO4), and bone-remodeling markers as manifested by hypoparathyroidism and hyperparathyroidism, renal insufficiency, daily PTH 1-34 administration, and receptor activator of NF-kappaB ligand (RANKL) inhibition. This model highlights the utility of systems approaches to physiologic modeling in the bone field. The presented bone and calcium homeostasis model provides an integrated mathematical construct to conduct hypothesis testing of influential system aspects, to visualize elements of this complex endocrine system, and to continue to build upon iteratively with the results of ongoing scientific research.
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Affiliation(s)
- Mark C Peterson
- Amgen, Inc., One Amgen Center Drive, MS 28-3-B, Thousand Oaks, CA 91320, USA.
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34
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Wongdee K, Riengrojpitak S, Krishnamra N, Charoenphandhu N. Claudin expression in the bone-lining cells of female rats exposed to long-standing acidemia. Exp Mol Pathol 2009; 88:305-10. [PMID: 20035748 DOI: 10.1016/j.yexmp.2009.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/09/2009] [Accepted: 12/09/2009] [Indexed: 10/20/2022]
Abstract
Besides enhancing osteoclast-mediated bone resorption, chronic metabolic acidosis (CMA) induces mineral efflux across the epithelial-like bone membrane formed by bone-lining cells (inactive osteoblasts), possibly via the paracellular pathway. However, there was a compensatory mechanism that restricted bone loss in the late phase of CMA, and changes in the expression of claudins, which are tight junction proteins known to regulate epithelial barrier function, were therefore anticipated in bone-lining cells. Herein, primary rat osteoblasts were found to express several transcripts of claudins, i.e., claudin-5, -11, -14, -15 and -16. Their protein expressions in bone-lining cells were demonstrated by immunohistochemistry in decalcified tibial sections. After exposure to CMA induced by oral administration of 1.5% NH(4)Cl for 21 days, expression of claudin-14, which normally seals the paracellular space and restricts ion movement, was increased, whereas that of claudin-15 and -16 which form pores for ion transport were decreased. Expressions of claudin-5 and -11 were not changed by CMA. In conclusion, the bone-lining cells of rats exposed to CMA for 21 days upregulated an ion-restrictive claudin (i.e., claudin-14), while downregulating ion-permeable claudins (i.e., claudin-15 and -16). These cellular responses might be parts of a compensatory mechanism accounting for deceleration of bone loss in late CMA.
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Affiliation(s)
- Kannikar Wongdee
- Consortium for Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok, Thailand
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35
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Donida BM, Mrak E, Gravaghi C, Villa I, Cosentino S, Zacchi E, Perego S, Rubinacci A, Fiorilli A, Tettamanti G, Ferraretto A. Casein phosphopeptides promote calcium uptake and modulate the differentiation pathway in human primary osteoblast-like cells. Peptides 2009; 30:2233-41. [PMID: 19682523 DOI: 10.1016/j.peptides.2009.08.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 08/03/2009] [Accepted: 08/04/2009] [Indexed: 11/23/2022]
Abstract
Casein phosphopeptides (CPPs), originating by in vitro and/or in vivo casein digestion, are characterized by the ability to complex and solubilize calcium ions preventing their precipitation. Previous works demonstrated that CPPs improve calcium uptake by human differentiated intestinal tumor cell lines, are able to re-mineralize carious lesions in a dental enamel, and, as components of a diet, affect bone weight and calcium content in rats. The aim of the present study was to evaluate if CPPs can directly modulate bone cells activity and mineralization. Primary human osteoblast-like cells were established in culture from trabecular bone samples obtained from waste materials during orthopedic surgery. Commercial mixtures of bovine casein phosphopeptides were used. The CPP dependent intracellular calcium rises were monitored at the single cell level through fura2-fluorescence assays. Results show that CPPs: (i) stimulate calcium uptake by primary human osteoblast-like cells; (ii) increase the expression and activity of alkaline phosphatase, a marker of human osteoblast differentiation; (iii) affect the cell proliferation rate and the apoptotic level; (iv) enhance nodule formation by human SaOS-2. Taken together these results confirm the possibility that CPPs play a role as modulator of bone cell activity, probably sustained by their ability as calcium carriers. Although the exact mechanism by which CPPs act remains not completely clarified, they can be considered as potential anabolic factors for bone tissue engineering.
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Affiliation(s)
- Bianca Maria Donida
- Dipartimento di Chimica, Biochimica e Biotecnologie per la Medicina, Università degli Studi di Milano, LITA, Via Fratelli Cervi 93, 20090 Segrate, Italy
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36
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Rubinacci A. Expanding the functional spectrum of vitamin K in bone. Focus on: “Vitamin K promotes mineralization, osteoblast to osteocyte transition, and an anti-catabolic phenotype by γ-carboxylation-dependent and -independent mechanisms”. Am J Physiol Cell Physiol 2009; 297:C1336-8. [DOI: 10.1152/ajpcell.00452.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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37
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ADA-deficient SCID is associated with a specific microenvironment and bone phenotype characterized by RANKL/OPG imbalance and osteoblast insufficiency. Blood 2009; 114:3216-26. [PMID: 19633200 DOI: 10.1182/blood-2009-03-209221] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenosine deaminase (ADA) deficiency is a disorder of the purine metabolism leading to combined immunodeficiency and systemic alterations, including skeletal abnormalities. We report that ADA deficiency in mice causes a specific bone phenotype characterized by alterations of structural properties and impaired mechanical competence. These alterations are the combined result of an imbalanced receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin axis, causing decreased osteoclastogenesis and an intrinsic defect of osteoblast function with subsequent low bone formation. In vitro, osteoblasts lacking ADA displayed an altered transcriptional profile and growth reduction. Furthermore, the bone marrow microenvironment of ADA-deficient mice showed a reduced capacity to support in vitro and in vivo hematopoiesis. Treatment of ADA-deficient neonatal mice with enzyme replacement therapy, bone marrow transplantation, or gene therapy resulted in full recovery of the altered bone parameters. Remarkably, untreated ADA-severe combined immunodeficiency patients showed a similar imbalance in RANKL/osteoprotegerin levels alongside severe growth retardation. Gene therapy with ADA-transduced hematopoietic stem cells increased serum RANKL levels and children's growth. Our results indicate that the ADA metabolism represents a crucial modulatory factor of bone cell activities and remodeling.
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Talmage RV, Mobley HT. The concentration of free calcium in plasma is set by the extracellular action of noncollagenous proteins and hydroxyapatite. Gen Comp Endocrinol 2009; 162:245-50. [PMID: 19361508 DOI: 10.1016/j.ygcen.2009.03.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 03/26/2009] [Accepted: 03/31/2009] [Indexed: 11/19/2022]
Abstract
The late Wm. F. Neuman frequently included the following statement in his speeches: "Plasma calcium is undersaturated in respect to itself, but supersaturated in respect to bone". As a physical chemist he knew that if plasma or extracellular fluid came in direct contact with bone surfaces plasma calcium level should fall to the saturated solubility of hydroxyapatite. How could the condition given in the quote exist? He answered this question by laboratory experiments but unfortunately died before he could explain it scientifically. In the current perspective article we feel that we cannot only explain Neuman's riddle but also use the answer to describe a revised premise for extracellular control of calcium concentrations in body fluids. The answer lies in the solubility of hydroxyapatite. A simple contact of bone mineral surface with body fluids should lead to a calcium concentration in plasma too low to support life. The evolutionary process prevented this by adding one or more noncollagenous proteins at the surface of hydroxyapatite. These proteins elevated the saturated solubility of the crystal latticework sufficiently to provide a calcium concentration that would sustain life. This report explains the solubility process in as much detail as our scientific information will permit and also includes the role of parathyroid hormone in the process. We hope that serious study of our article will permit acceptance of our premise for calcium control and induce further study that should demonstrate its importance in all aspects of bone metabolism.
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Affiliation(s)
- R V Talmage
- Department of Orthopaedics, UNC School of Medicine, Chapel Hill, NC, USA.
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39
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Pajevic PD. Regulation of bone resorption and mineral homeostasis by osteocytes. ACTA ACUST UNITED AC 2009. [DOI: 10.1138/20090363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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40
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Teti A, Zallone A. Do osteocytes contribute to bone mineral homeostasis? Osteocytic osteolysis revisited. Bone 2009; 44:11-6. [PMID: 18977320 DOI: 10.1016/j.bone.2008.09.017] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 09/10/2008] [Accepted: 09/20/2008] [Indexed: 10/21/2022]
Abstract
Osteocytes are cells buried in the bone matrix. They largely contribute to the regulation of bone remodeling in response to mechanical and microenvironmental changes. Much has been recognized in recent years regarding the role of osteocytes in bone homeostasis, nevertheless their ability to directly contribute to mineral equilibrium has been neglected. In the light of the renewed interest in their biology, we revisited the literature and discuss experimental evidence favoring the hypothesis that osteocytes are able to remove and replace the bone matrix according to the systemic needs of the body. We also reviewed reports against this theory, thus providing current views of what is known so far on the ability of osteocytes to mobilize bone mineral. This re-examination of osteocytic osteolysis might stimulate new interest and open new perspectives in osteocyte biology and in the cellular mechanisms that control bone homeostasis.
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Affiliation(s)
- Anna Teti
- Department of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
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41
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Wongdee K, Pandaranandaka J, Teerapornpuntakit J, Tudpor K, Thongbunchoo J, Thongon N, Jantarajit W, Krishnamra N, Charoenphandhu N. Osteoblasts express claudins and tight junction-associated proteins. Histochem Cell Biol 2008; 130:79-90. [PMID: 18365232 DOI: 10.1007/s00418-008-0419-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2008] [Indexed: 11/28/2022]
Abstract
Osteoblasts were previously reported to form tight junctions, which may play an important role in the regulation of ion transport across the epithelial-like bone membrane. However, the evidence for the presence of tight junction-associated proteins in osteoblasts is lacking. We therefore studied the expression of tight junction-associated genes in primary rat osteoblasts and bone tissues. Quantitative real-time PCR showed that osteoblasts expressed ZO-1, -2, -3, cingulin, occludin, claudin-1 to -12, -14 to -20, -22 and -23. By using western blot analyses of selected claudins, expression of claudin-5, -11, -14 and -15, but not claudin-3, were identified in osteoblasts. A confocal immunofluorescent study in undecalcified tibial sections confirmed that claudin-16 was localized on the trabecular surface, normally covered by osteoblasts and bone-lining cells. In addition, immunohistochemical studies in decalcified tibial sections demonstrated the expression of claudin-5, -11, -14, -15 and -16 in bone-lining cells (inactive osteoblasts). Primary osteoblasts cultured in the Snapwell for 19-26 days were found to form a monolayer with measurable transepithelial resistance of approximately 110-180 Omegacm(2), confirming the presence of barrier functions of the tight junction. It was concluded that osteoblasts expressed several tight junction-associated proteins, which possibly regulated ion transport across the bone membrane.
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Affiliation(s)
- Kannikar Wongdee
- Consortium for Calcium and Bone Research, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
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Talmage RV, Mobley HT. Calcium homeostasis: reassessment of the actions of parathyroid hormone. Gen Comp Endocrinol 2008; 156:1-8. [PMID: 18160068 DOI: 10.1016/j.ygcen.2007.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 10/28/2007] [Accepted: 11/03/2007] [Indexed: 11/29/2022]
Abstract
The purpose of this report is to adjust our interpretation of the actions of parathyroid hormone (PTH) to include its action on the bone mineral-noncollagenous protein interactions at all bone surfaces. The three primary areas that respond to PTH are: (1) all bone surface areas in contact with the extracellular fluid (ECF), (2) the kidney, and indirectly the intestinal tract, and (3) the bone remodeling sequence. The primary rapid action of the hormone is to set and maintain the free calcium concentration of the ECF. This it does by raising the equilibrium level at bone mineral surfaces. It affects the noncollagenous protein bone mineral process to raise the free calcium level in the ECF from the base level of 3.5mg/100ml to the physiological level of 5.0mg/100ml. Maintaining the higher level requires continuous secretion of parathyroid hormone. The action of PTH at bone surfaces tends to be catabolic in nature in regard to bone loss. The hormone also acts on the kidney to raise the threshold for calcium reabsorption and by stimulation of renal hydroxylation of vitamin D to increase intestinal absorption of calcium. Its action here is to supply the ECF with calcium derived from food intake. This is the extent of PTH action on renal processes. PTH acts on all three steps in the bone remodeling process. While its total function here is not clear, the result is a net increase in the synthesis of collagen. The report concludes by comparing the actions of PTH as proposed here to the functions of PTH that have been proposed in the past.
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Affiliation(s)
- Roy V Talmage
- Department of Orthopaedics, UNC School of Medicine, Chapel Hill, NC, USA.
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Reid B, Nuccitelli R, Zhao M. Non-invasive measurement of bioelectric currents with a vibrating probe. Nat Protoc 2007; 2:661-9. [PMID: 17406628 DOI: 10.1038/nprot.2007.91] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Small d.c. electrical signals have been detected in many biological systems and often serve important functions in cells and organs. For example, we have recently found that they play a far more important role in directing cell migration in wound healing than previously thought. Here, we describe the manufacture and use of a simplified ultrasensitive vibrating probe system for measuring extracellular electrical currents. This vibrating probe is an insulated, sharpened metal wire with a small platinum-black tip (10-30 microm), which can detect ionic currents in the microA cm(-2) range in physiological saline. The probe is vibrated at about 300 Hz by a piezoelectric bender. In the presence of an ionic current, the probe detects a voltage difference between the extremes of its movement. The basic, low-cost system we describe is readily adaptable to most laboratories interested in measuring physiological electric currents associated with wounds, developing embryos and other biological systems.
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Affiliation(s)
- Brian Reid
- School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
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Lundquist P, Murer H, Biber J. Type II Na+-Pi cotransporters in osteoblast mineral formation: regulation by inorganic phosphate. Cell Physiol Biochem 2007; 19:43-56. [PMID: 17310099 DOI: 10.1159/000099191] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2006] [Indexed: 01/09/2023] Open
Abstract
During calcification of bone, large amounts of phosphate (P(i)) must be transported from the circulation to the osteoid. Likely candidates for osteoblast P(i) transport are the type II sodium-phosphate cotransporters NaPi-IIa and NaPi-IIb that facilitate transcellular P(i) flux in kidney and intestine, respectively. We have therefore determined the 'cotransporters' expression in osteoblast-like cells. We have also studied the 'cotransporters' regulation by P(i) and during mineralization in vitro. Phosphate uptake and cotransporter protein expression was investigated at early, late and mineralizing culture stages of mouse (MC3T3-E1) and rat (UMR-106) osteoblast-like cells. Both NaPi-IIa and NaPi-IIb were expressed by both osteoblast-like cell lines. NaPi-IIa was upregulated in both cell lines one week after confluency. After 7 days in 3mM P(i) NaPi-IIa was strongly upregulated in both cell lines. NaPi-IIb expression was unaffected by both culture stage and P(i) supplementation. The expression of both cotransporters was unaffected by P(i) deprivation. In vitro mineralization at 1.5mM P(i) was preceded by a three-fold increase in osteoblast sodium-dependent P(i) uptake and a corresponding upregulation of both NaPi-IIa and NaPi-IIb. Their expression thus seem regulated by phosphate in a manner consistent with their playing a role in transcellular P(i) flux during mineralization.
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Affiliation(s)
- Patrik Lundquist
- Institute for Physiology and Center for Integrative Human Physiology, University of Zürich, Switzerland.
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Inoue K, Mikuni-Takagaki Y, Oikawa K, Itoh T, Inada M, Noguchi T, Park JS, Onodera T, Krane SM, Noda M, Itohara S. A crucial role for matrix metalloproteinase 2 in osteocytic canalicular formation and bone metabolism. J Biol Chem 2006; 281:33814-24. [PMID: 16959767 DOI: 10.1074/jbc.m607290200] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Extracellular matrix production and degradation by bone cells are critical steps in bone metabolism. Mutations of the gene encoding MMP-2, an extracellular matrix-degrading enzyme, are associated with a human genetic disorder characterized by subcutaneous nodules, arthropathy, and focal osteolysis. It is not known how the loss of MMP-2 function results in the pathology. Here, we show that Mmp2(-/-) mice exhibited opposing bone phenotypes caused by an impaired osteocytic canalicular network. Mmp2(-/-) mice showed decreased bone mineral density in the limb and trunk bones but increased bone volume in the calvariae. In the long bones, there was moderate disruption of the osteocytic networks and reduced bone density throughout life, whereas osteoblast and osteoclast function was normal. In contrast, aged but not young Mmp2(-/-) mice had calvarial sclerosis with osteocyte death. Severe disruption of the osteocytic networks preceded osteocyte loss in Mmp2(-/-) calvariae. Successful transplantation of wild-type periosteum restored the osteocytic canalicular networks in the Mmp2(-/-) calvariae, suggesting local roles of MMP-2 in determining bone phenotypes. Our results indicate that MMP-2 plays a crucial role in forming and maintaining the osteocytic canalicular network, and we propose that osteocytic network formation is a determinant of bone remodeling and mineralization.
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Affiliation(s)
- Keiichi Inoue
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
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