1
|
Lim DZ, Macbain M, Kok M, Wiggins G, Abbouchie H, Lee ST, Lau E, Lim RP, Chiang C, Kutaiba N. Opportunistic screening for osteoporosis using routine clinical care computed tomography brain studies. Skeletal Radiol 2024:10.1007/s00256-024-04703-6. [PMID: 38755335 DOI: 10.1007/s00256-024-04703-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/18/2024]
Abstract
OBJECTIVE Osteoporosis and falls are both prevalent in the elderly, and CT brain (CTB) is frequently performed post head-strike. We aim to validate the relationship between frontal bone density (Hounsfield unit) from routine CTB and bone mineral density from dual-energy X-ray absorptiometry (DEXA) scan for opportunistic osteoporosis screening. MATERIALS AND METHODS Patients who had a non-contrast CTB followed by a DEXA scan in the subsequent year were included in this multi-center retrospective study. The relationship between frontal bone density on CT and femoral neck T-score on DEXA was examined using ANOVA, Pearson's correlation, and receiver operating curve (ROC) analysis. Sensitivity, specificity, negative and positive predictive values, and area under the curve (AUC) were calculated. RESULTS Three hundred twenty-six patients (205 females and 121 males) were analyzed. ANOVA analysis showed that frontal bone density was lower in patients with DEXA-defined osteoporosis (p < 0.001), while Pearson's correlation analysis demonstrated a fair correlation with femoral neck T-score (r = 0.3, p < 0.001). On subgroup analysis, these were true in females but not in males. On ROC analysis, frontal bone density weakly predicted osteoporosis (AUC 0.6, 95% CI 0.5-0.7) with no optimal threshold identified. HU < 610 was highly specific (87.5%) but poorly sensitive (18.9%). HU > 1200 in females had a strong negative predictive value for osteoporosis (92.6%, 95% CI 87.1-98.1%). CONCLUSION Frontal bone density from routine CTB is significantly different between females with and without osteoporosis, but not between males. However, frontal bone density was a weak predictor for DEXA-defined osteoporosis. Further research is required to determine the role of CTB in opportunistic osteoporosis screening.
Collapse
Affiliation(s)
- Dee Zhen Lim
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia.
| | - Milo Macbain
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Marcus Kok
- Department of Radiology, Eastern Health, 8 Arnold Street, Box Hill, VIC, 3128, Australia
| | - Ghanda Wiggins
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Hussein Abbouchie
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Sze Ting Lee
- Department of Molecular Imaging and Therapy, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
- University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia
| | - Eddie Lau
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
- Department of Molecular Imaging and Therapy, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
- University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia
| | - Ruth P Lim
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
- University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia
| | - Cherie Chiang
- University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia
- Department of Endocrinology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
| | - Numan Kutaiba
- Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia
- Department of Radiology, Eastern Health, 8 Arnold Street, Box Hill, VIC, 3128, Australia
- University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia
| |
Collapse
|
2
|
Raman R, Antony M, Nivelle R, Lavergne A, Zappia J, Guerrero-Limón G, Caetano da Silva C, Kumari P, Sojan JM, Degueldre C, Bahri MA, Ostertag A, Collet C, Cohen-Solal M, Plenevaux A, Henrotin Y, Renn J, Muller M. The Osteoblast Transcriptome in Developing Zebrafish Reveals Key Roles for Extracellular Matrix Proteins Col10a1a and Fbln1 in Skeletal Development and Homeostasis. Biomolecules 2024; 14:139. [PMID: 38397376 PMCID: PMC10886564 DOI: 10.3390/biom14020139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/05/2024] [Accepted: 01/11/2024] [Indexed: 02/25/2024] Open
Abstract
Zebrafish are now widely used to study skeletal development and bone-related diseases. To that end, understanding osteoblast differentiation and function, the expression of essential transcription factors, signaling molecules, and extracellular matrix proteins is crucial. We isolated Sp7-expressing osteoblasts from 4-day-old larvae using a fluorescent reporter. We identified two distinct subpopulations and characterized their specific transcriptome as well as their structural, regulatory, and signaling profile. Based on their differential expression in these subpopulations, we generated mutants for the extracellular matrix protein genes col10a1a and fbln1 to study their functions. The col10a1a-/- mutant larvae display reduced chondrocranium size and decreased bone mineralization, while in adults a reduced vertebral thickness and tissue mineral density, and fusion of the caudal fin vertebrae were observed. In contrast, fbln1-/- mutants showed an increased mineralization of cranial elements and a reduced ceratohyal angle in larvae, while in adults a significantly increased vertebral centra thickness, length, volume, surface area, and tissue mineral density was observed. In addition, absence of the opercle specifically on the right side was observed. Transcriptomic analysis reveals up-regulation of genes involved in collagen biosynthesis and down-regulation of Fgf8 signaling in fbln1-/- mutants. Taken together, our results highlight the importance of bone extracellular matrix protein genes col10a1a and fbln1 in skeletal development and homeostasis.
Collapse
Affiliation(s)
- Ratish Raman
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| | - Mishal Antony
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| | - Renaud Nivelle
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| | - Arnaud Lavergne
- GIGA Genomics Platform, B34, GIGA Institute, University of Liège, 4000 Liège, Belgium;
| | - Jérémie Zappia
- MusculoSKeletal Innovative Research Lab, Center for Interdisciplinary Research on Medicines, University of Liège, 4000 Liège, Belgium (Y.H.)
| | - Gustavo Guerrero-Limón
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| | - Caroline Caetano da Silva
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Priyanka Kumari
- Laboratory of Pharmaceutical and Analytical Chemistry, Department of Pharmacy, CIRM, Sart Tilman, 4000 Liège, Belgium;
| | - Jerry Maria Sojan
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy;
| | - Christian Degueldre
- GIGA CRC In Vivo Imaging, University of Liège, Sart Tilman, 4000 Liège, Belgium; (C.D.); (M.A.B.); (A.P.)
| | - Mohamed Ali Bahri
- GIGA CRC In Vivo Imaging, University of Liège, Sart Tilman, 4000 Liège, Belgium; (C.D.); (M.A.B.); (A.P.)
| | - Agnes Ostertag
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Corinne Collet
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
- UF de Génétique Moléculaire, Hôpital Robert Debré, APHP, F-75019 Paris, France
| | - Martine Cohen-Solal
- Hospital Lariboisière, Reference Centre for Rare Bone Diseases, INSERM U1132, Université de Paris-Cité, F-75010 Paris, France; (C.C.d.S.); (A.O.); (C.C.); (M.C.-S.)
| | - Alain Plenevaux
- GIGA CRC In Vivo Imaging, University of Liège, Sart Tilman, 4000 Liège, Belgium; (C.D.); (M.A.B.); (A.P.)
| | - Yves Henrotin
- MusculoSKeletal Innovative Research Lab, Center for Interdisciplinary Research on Medicines, University of Liège, 4000 Liège, Belgium (Y.H.)
| | - Jörg Renn
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| | - Marc Muller
- Laboratory for Organogenesis and Regeneration (LOR), GIGA Institute, University of Liège, 4000 Liège, Belgium; (R.R.); (M.A.); (R.N.); (G.G.-L.); (J.R.)
| |
Collapse
|
3
|
Isaac J, Clerc MM, Ferré FC, Fournier BPJ. [Oral mesenchymal cells, a specific niche, from development to regeneration]. Med Sci (Paris) 2024; 40:24-29. [PMID: 38299899 DOI: 10.1051/medsci/2023191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024] Open
Abstract
Oral buccal tissues, including bone and mucosa, have unique properties. Oral mucosal fibroblasts and jaw osteoblasts, both derived from Cranial Neural Crest cells, play a key role in healing and repair. These cells express a specific repertoire of genes with their regenerative properties, but also craniofacial diseases. Understanding these tissues holds clinical promise for tissue regeneration and repair of bone and mucosal defects. These multidisciplinary advances also offer potential for better management of periodontal-related conditions and improved oral health.
Collapse
Affiliation(s)
- Juliane Isaac
- Centre de recherche des Cordeliers, UMRS 1138, Molecular Oral Pathophysiology Lab, université Paris Cité, Inserm, Sorbonne université, Paris, France - Université Paris Cité, UFR odontologie, département de biologie orale, Paris, France
| | - Mélodie M Clerc
- Centre de recherche des Cordeliers, UMRS 1138, Molecular Oral Pathophysiology Lab, université Paris Cité, Inserm, Sorbonne université, Paris, France - Reference center for oral and dental rare diseases, ORARES, Odontology department, hôpital Rothschild, APHP, Paris, France
| | - François C Ferré
- Centre de recherche des Cordeliers, UMRS 1138, Molecular Oral Pathophysiology Lab, université Paris Cité, Inserm, Sorbonne université, Paris, France - Université Paris Cité, UFR odontologie, département de chirurgie orale, Paris, France - Service de chirurgie orale, hôpital Charles Foix, AP-HP, Ivry-Sur‑Seine, France
| | - Benjamin P J Fournier
- Centre de recherche des Cordeliers, UMRS 1138, Molecular Oral Pathophysiology Lab, université Paris Cité, Inserm, Sorbonne université, Paris, France - Université Paris Cité, UFR odontologie, département de biologie orale, Paris, France - Reference center for oral and dental rare diseases, ORARES, Odontology department, hôpital Rothschild, APHP, Paris, France
| |
Collapse
|
4
|
Bhattacharyya ND, Kyaw W, McDonald MM, Dhenni R, Grootveld AK, Xiao Y, Chai R, Khoo WH, Danserau LC, Sergio CM, Timpson P, Lee WM, Croucher PI, Phan TG. Minimally invasive longitudinal intravital imaging of cellular dynamics in intact long bone. Nat Protoc 2023; 18:3856-3880. [PMID: 37857852 DOI: 10.1038/s41596-023-00894-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 07/28/2023] [Indexed: 10/21/2023]
Abstract
Intravital two-photon microscopy enables deep-tissue imaging at high temporospatial resolution in live animals. However, the endosteal bone compartment and underlying bone marrow pose unique challenges to optical imaging as light is absorbed, scattered and dispersed by thick mineralized bone matrix and the adipose-rich bone marrow. Early bone intravital imaging methods exploited gaps in the cranial sutures to bypass the need to penetrate through cortical bone. More recently, investigators have developed invasive methods to thin the cortical bone or implant imaging windows to image cellular dynamics in weight-bearing long bones. Here, we provide a step-by-step procedure for the preparation of animals for minimally invasive, nondestructive, longitudinal intravital imaging of the murine tibia. This method involves the use of mixed bone marrow radiation chimeras to unambiguously double-label osteoclasts and osteomorphs. The tibia is exposed by a simple skin incision and an imaging chamber constructed using thermoconductive T-putty. Imaging sessions up to 12 h long can be repeated over multiple timepoints to provide a longitudinal time window into the endosteal and marrow niches. The approach can be used to investigate cellular dynamics in bone remodeling, cancer cell life cycle and hematopoiesis, as well as long-lived humoral and cellular immunity. The procedure requires an hour to complete and is suitable for users with minimal prior expertise in small animal surgery.
Collapse
Affiliation(s)
- Nayan Deger Bhattacharyya
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Wunna Kyaw
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Michelle M McDonald
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Rama Dhenni
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Abigail K Grootveld
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Ya Xiao
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Ryan Chai
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Weng Hua Khoo
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
| | - Linda C Danserau
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
- ACRF INCITe Centre for Intravital Imaging of Niches for Cancer Immune Therapy, Sydney, New South Wales, Australia
| | - C Marcelo Sergio
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Paul Timpson
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
- ACRF INCITe Centre for Intravital Imaging of Niches for Cancer Immune Therapy, Sydney, New South Wales, Australia
| | - Woei Ming Lee
- ACRF INCITe Centre for Intravital Imaging of Niches for Cancer Immune Therapy, Sydney, New South Wales, Australia
- John Curtin School of Medical Research, Australian National University, Canberra, New South Wales, Australia
| | - Peter I Croucher
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
- ACRF INCITe Centre for Intravital Imaging of Niches for Cancer Immune Therapy, Sydney, New South Wales, Australia
| | - Tri Giang Phan
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia.
- St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia.
- ACRF INCITe Centre for Intravital Imaging of Niches for Cancer Immune Therapy, Sydney, New South Wales, Australia.
| |
Collapse
|
5
|
Alexander A, Herz J, Calvier L. Reelin through the years: From brain development to inflammation. Cell Rep 2023; 42:112669. [PMID: 37339050 PMCID: PMC10592530 DOI: 10.1016/j.celrep.2023.112669] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/09/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023] Open
Abstract
Reelin was originally identified as a regulator of neuronal migration and synaptic function, but its non-neuronal functions have received far less attention. Reelin participates in organ development and physiological functions in various tissues, but it is also dysregulated in some diseases. In the cardiovascular system, Reelin is abundant in the blood, where it contributes to platelet adhesion and coagulation, as well as vascular adhesion and permeability of leukocytes. It is a pro-inflammatory and pro-thrombotic factor with important implications for autoinflammatory and autoimmune diseases such as multiple sclerosis, Alzheimer's disease, arthritis, atherosclerosis, or cancer. Mechanistically, Reelin is a large secreted glycoprotein that binds to several membrane receptors, including ApoER2, VLDLR, integrins, and ephrins. Reelin signaling depends on the cell type but mostly involves phosphorylation of NF-κB, PI3K, AKT, or JAK/STAT. This review focuses on non-neuronal functions and the therapeutic potential of Reelin, while highlighting secretion, signaling, and functional similarities between cell types.
Collapse
Affiliation(s)
- Anna Alexander
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX, USA; Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, USA; Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Calvier
- Department of Molecular Genetics, University of Texas (UT) Southwestern Medical Center, Dallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
6
|
Janssen JN, Kalev-Altman R, Shalit T, Sela-Donenfeld D, Monsonego-Ornan E. Differential gene expression in the calvarial and cortical bone of juvenile female mice. Front Endocrinol (Lausanne) 2023; 14:1127536. [PMID: 37378024 PMCID: PMC10291685 DOI: 10.3389/fendo.2023.1127536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/21/2023] [Indexed: 06/29/2023] Open
Abstract
Introduction Both the calvarial and the cortical bones develop through intramembranous ossification, yet they have very different structures and functions. The calvaria enables the rapid while protected growth of the brain, whereas the cortical bone takes part in locomotion. Both types of bones undergo extensive modeling during embryonic and post-natal growth, while bone remodeling is the most dominant process in adults. Their shared formation mechanism and their highly distinct functions raise the fundamental question of how similar or diverse the molecular pathways that act in each bone type are. Methods To answer this question, we aimed to compare the transcriptomes of calvaria and cortices from 21-day old mice by bulk RNA-Seq analysis. Results The results revealed clear differences in expression levels of genes related to bone pathologies, craniosynostosis, mechanical loading and bone-relevant signaling pathways like WNT and IHH, emphasizing the functional differences between these bones. We further discussed the less expected candidate genes and gene sets in the context of bone. Finally, we compared differences between juvenile and mature bone, highlighting commonalities and dissimilarities of gene expression between calvaria and cortices during post-natal bone growth and adult bone remodeling. Discussion Altogether, this study revealed significant differences between the transcriptome of calvaria and cortical bones in juvenile female mice, highlighting the most important pathway mediators for the development and function of two different bone types that originate both through intramembranous ossification.
Collapse
Affiliation(s)
- Jerome Nicolas Janssen
- The Institute of Biochemistry, Food Science and Nutrition, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Rotem Kalev-Altman
- The Institute of Biochemistry, Food Science and Nutrition, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- The Koret School of Veterinary Medicine, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Tali Shalit
- The Ilana and Pascal Mantoux Institute for Bioinformatics, The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Dalit Sela-Donenfeld
- The Koret School of Veterinary Medicine, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Efrat Monsonego-Ornan
- The Institute of Biochemistry, Food Science and Nutrition, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
7
|
Priyadarshi S, Hansdah K, Singh N, Bouzid A, Ray CS, Panda KC, Biswal NC, Desai A, Choudhury JC, Tekari A, Masmoudi S, Ramchander PV. The risks of RELN polymorphisms and its expression in the development of otosclerosis. PLoS One 2022; 17:e0269558. [PMID: 35658052 PMCID: PMC9165908 DOI: 10.1371/journal.pone.0269558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 05/23/2022] [Indexed: 11/19/2022] Open
Abstract
Otosclerosis (OTSC) is the primary form of conductive hearing loss characterized by abnormal bone remodelling within the otic capsule of the human middle ear. A genetic association of the RELN SNP rs3914132 with OTSC has been identified in European population. Previously, we showed a trend towards association of this polymorphism with OTSC and identified a rare variant rs74503667 in a familial case. Here, we genotyped these variants in an Indian cohort composed of 254 OTSC cases and 262 controls. We detected a significant association of rs3914132 with OTSC (OR = 0.569, 95%CI = 0.386–0.838, p = 0.0041). To confirm this finding, we completed a meta-analysis which revealed a significant association of the rs3914132 polymorphism with OTSC (Z = 6.707, p<0.0001) across different ethnic populations. Linkage analysis found the evidence of linkage at RELN locus (LOD score 2.1059) in the OTSC family which has shown the transmission of rare variant rs74503667 in the affected individuals. To understand the role of RELN and its receptors in the development of OTSC, we went further to perform a functional analysis of RELN/reelin. Here we detected a reduced RELN (p = 0.0068) and VLDLR (p = 0.0348) mRNA levels in the otosclerotic stapes tissues. Furthermore, a reduced reelin protein expression by immunohistochemistry was confirmed in the otosclerotic tissues. Electrophoretic mobility shift assays for rs3914132 and rs74503667 variants revealed an altered binding of transcription factors in the mutated sequences which indicates the regulatory role of these variations in the RELN gene regulation. Subsequently, we showed by scanning electron microscopy a change in stapes bone morphology of otosclerotic patients. In conclusion, this study evidenced that the rare variation rs74503667 and the common polymorphism rs3914132 in the RELN gene and its reduced expressions that were associated with OTSC.
Collapse
Affiliation(s)
- Saurabh Priyadarshi
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Kirtal Hansdah
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Neha Singh
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India
| | - Amal Bouzid
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Chinmay Sundar Ray
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | | | - Narayan Chandra Biswal
- Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | - Ashim Desai
- Dr. ABR Desai Ear, Nose and Throat (ENT) Clinic and Research Centre, Mumbai, India
| | - Jyotish Chandra Choudhury
- Department of Forensic Medicine & Toxicology (FMT), Shrirama Chandra Bhanj (SCB) Medical College & Hospital, Cuttack, India
| | - Adel Tekari
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Saber Masmoudi
- Laboratory of Molecular and Cellular Screening Processes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | | |
Collapse
|
8
|
Nassif A, Lignon G, Asselin A, Zadikian CC, Petit S, Sun HW, Klein C, Ferré FC, Morasso MI, Berdal A, Fournier BPJ, Isaac J. Transcriptional Regulation of Jaw Osteoblasts: Development to Pathology. J Dent Res 2022; 101:859-869. [PMID: 35148649 DOI: 10.1177/00220345221074356] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Craniofacial and jaw bones have unique physiological specificities when compared to axial and appendicular bones. However, the molecular profile of the jaw osteoblast (OB) remains incomplete. The present study aimed to decipher the bone site-specific profiles of transcription factors (TFs) expressed in OBs in vivo. Using RNA sequencing analysis, we mapped the transcriptome of confirmed OBs from 2 different skeletal sites: mandible (Md) and tibia (Tb). The OB transcriptome contains 709 TF genes: 608 are similarly expressed in Md-OB and Tb-OB, referred to as "OB-core"; 54 TF genes are upregulated in Md-OB, referred to as "Md-set"; and 18 TF genes are upregulated in Tb-OB, referred to as "Tb-set." Notably, the expression of 29 additional TF genes depends on their RNA transcript variants. TF genes with no previously known role in OBs and bone were identified. Bioinformatics analysis combined with review of genetic disease databases and a comprehensive literature search showed a significant contribution of anatomical origin to the OB signatures. Md-set and Tb-set are enriched with site-specific TF genes associated with development and morphogenesis (neural crest vs. mesoderm), and this developmental imprint persists during growth and homeostasis. Jaw and tibia site-specific OB signatures are associated with craniofacial and appendicular skeletal disorders as well as neurocristopathies, dental disorders, and digit malformations. The present study demonstrates the feasibility of a new method to isolate pure OB populations and map their gene expression signature in the context of OB physiological environment, avoiding in vitro culture and its associated biases. Our results provide insights into the site-specific developmental pathways governing OBs and identify new major OB regulators of bone physiology. We also established the importance of the OB transcriptome as a prognostic tool for human rare bone diseases to explore the hidden pathophysiology of craniofacial malformations, among the most prevalent congenital defects in humans.
Collapse
Affiliation(s)
- A Nassif
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France.,AP-HP, Reference Center for Dental Rare Diseases, Rothschild Hospital (ORARES), Paris, France.,AP-HP, Pitié Salpêtrière, Service d'Orthopédie Dento-faciale, Paris, France
| | - G Lignon
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France
| | - A Asselin
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France
| | - C C Zadikian
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France
| | - S Petit
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France
| | - H W Sun
- Biodata Mining and Discovery Section, Office of Science and Technology, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - C Klein
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Histology, Cell Imaging and Flow Cytometry Platform (CHIC), Paris, France
| | - F C Ferré
- Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France.,AP-HP, Charles Foix-Pitié Salpêtrière Hospital, Dental Department, Ivry, France
| | - M I Morasso
- Laboratory of Skin Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - A Berdal
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France.,AP-HP, Reference Center for Dental Rare Diseases, Rothschild Hospital (ORARES), Paris, France
| | - B P J Fournier
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France.,AP-HP, Reference Center for Dental Rare Diseases, Rothschild Hospital (ORARES), Paris, France
| | - J Isaac
- Université de Paris, Dental Faculty, Department of Oral Biology, Paris, France.,Centre de Recherche des Cordeliers, Université de Paris, Sorbonne Université, Inserm, Laboratory of Molecular Oral Pathophysiology, Paris, France
| |
Collapse
|
9
|
Ward DL, Schroeder L, Tinius A, Niccoli S, Voth R, Lees SJ, Silcox M, Viola B, Sanzo P. Ovariectomized Rat Model and Shape Variation in the Bony Labyrinth. Anat Rec (Hoboken) 2022; 305:3283-3296. [PMID: 35103405 DOI: 10.1002/ar.24878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 11/10/2022]
Abstract
Postmenopausal osteoporosis is a serious concern in aging individuals, but has not been explored for its potential to alter the shape of the inner ear by way of increased remodelling in the otic capsule. The otic capsule, or bony labyrinth, is thought to experience uniquely limited remodelling after development due to high levels of osteoprotegerin. On this basis, despite the widespread remodelling that accompanies osteoporosis, we hypothesize that both the shape and volume of the semicircular canals will resist such changes. To test this hypothesis, we conducted three-dimensional geometric morphometric shape analysis on microcomputed tomographic data collected on the semicircular canals of an ovariectomized (OVX) rat model. A Procrustes ANOVA found no statistically significant differences in shape between surgery and sham groups, and morphological disparity testing likewise found no differences in shape variation. Univariate testing found no differences in semicircular volume between OVX and control groups. The range of variation in the OVX group, however, is greater than in the sham group but this difference does not reach statistical significance, perhaps because of a combination of small effect size and low sample size. This finding suggests that labyrinthine shape remains a tool for assessing phylogeny and function in the fossil record, but that it is possible that osteoporosis may be contributing to intraspecific shape variation in the bony labyrinth. This effect warrants further exploration at a microstructural level with continued focus on variables related to remodelling. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Devin L Ward
- University of Toronto, Department of Anthropology, Toronto, Ontario
| | - Lauren Schroeder
- University of Toronto Mississauga, Department of Anthropology, Mississauga, Ontario
| | - Alexander Tinius
- University of Toronto, Department of Ecology & Evolutionary Biology, Toronto, Ontario
| | - Sarah Niccoli
- Northern Ontario School of Medicine, Thunder Bay, Ontario
| | - Riley Voth
- Northern Ontario School of Medicine, Thunder Bay, Ontario
| | - Simon J Lees
- Northern Ontario School of Medicine, Thunder Bay, Ontario
| | - Mary Silcox
- University of Toronto Scarborough, Department of Anthropology, Scarborough, Ontario
| | - Bence Viola
- University of Toronto, Department of Anthropology, Toronto, Ontario
| | - Paolo Sanzo
- Lakehead University, Northern Ontario School of Medicine and School of Kinesiology, Thunder Bay, Ontario
| |
Collapse
|
10
|
Kague E, Medina-Gomez C, Boyadjiev SA, Rivadeneira F. The genetic overlap between osteoporosis and craniosynostosis. Front Endocrinol (Lausanne) 2022; 13:1020821. [PMID: 36225206 PMCID: PMC9548872 DOI: 10.3389/fendo.2022.1020821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/08/2022] [Indexed: 11/29/2022] Open
Abstract
Osteoporosis is the most prevalent bone condition in the ageing population. This systemic disease is characterized by microarchitectural deterioration of bone, leading to increased fracture risk. In the past 15 years, genome-wide association studies (GWAS), have pinpointed hundreds of loci associated with bone mineral density (BMD), helping elucidate the underlying molecular mechanisms and genetic architecture of fracture risk. However, the challenge remains in pinpointing causative genes driving GWAS signals as a pivotal step to drawing the translational therapeutic roadmap. Recently, a skull BMD-GWAS uncovered an intriguing intersection with craniosynostosis, a congenital anomaly due to premature suture fusion in the skull. Here, we recapitulate the genetic contribution to both osteoporosis and craniosynostosis, describing the biological underpinnings of this overlap and using zebrafish models to leverage the functional investigation of genes associated with skull development and systemic skeletal homeostasis.
Collapse
Affiliation(s)
- Erika Kague
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, United Kingdom
- *Correspondence: Erika Kague,
| | - Carolina Medina-Gomez
- Department of Internal Medicine, Erasmus Medical Center (MC), University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Simeon A. Boyadjiev
- Department of Pediatrics, University of California, Davis, Sacramento, CA, United States
| | - Fernando Rivadeneira
- Department of Oral and Maxillofacial Surgery, Erasmus Medical Center (MC), University Medical Center Rotterdam, Rotterdam, Netherlands
| |
Collapse
|
11
|
Tonina E, Larentis O, Tesi C, Fusco R, Campagnolo M, Licata M. A Severe Case of Biparietal Thinning in a Medieval Skull From a Northern Italy Necropolis. J Craniofac Surg 2022; 33:70-75. [PMID: 34260447 PMCID: PMC10010699 DOI: 10.1097/scs.0000000000007929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/06/2021] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT This study aims at presenting a case of symmetrical and bilateral thinning observed in a skull belonging to the skeleton of a mature woman from the medieval cemetery of Caravate (north Italy). Macroscopical, radiological, and histological analyses were performed to investigate the condition. The analyses allowed us to detect a progressive loss of both the outer table and the diploe, and the sparing of the inner table. As a controversial condition in the clinical and paleopathological literature, this case poses some difficulties in discussing the differential diagnosis. However, the sex determination, estimation of the age-at-death and different characteristics observed at the level of the postcranial bones, in particular the fractures recorded on different vertebral bodies, allowed us to correlate the biparietal thinning found in this subject to ageing and osteoporosis.
Collapse
Affiliation(s)
- Enrica Tonina
- Department of Biotechnologies and Life Sciences, Centre of Research in Osteoarchaeology and Paleopathology
| | - Omar Larentis
- Department of Biotechnologies and Life Sciences, Centre of Research in Osteoarchaeology and Paleopathology
| | - Chiara Tesi
- Department of Biotechnologies and Life Sciences, Centre of Research in Osteoarchaeology and Paleopathology
| | - Roberta Fusco
- Department of Biotechnologies and Life Sciences, Centre of Research in Osteoarchaeology and Paleopathology
| | - Monica Campagnolo
- Department of Biotechnologies and Life Sciences, Insubria University, Italy
| | - Marta Licata
- Department of Biotechnologies and Life Sciences, Centre of Research in Osteoarchaeology and Paleopathology
| |
Collapse
|
12
|
Ali E, Birch M, Hopper N, Rushton N, McCaskie AW, Brooks RA. Human osteoblasts obtained from distinct periarticular sites demonstrate differences in biological function in vitro. Bone Joint Res 2021; 10:611-618. [PMID: 34565180 PMCID: PMC8479562 DOI: 10.1302/2046-3758.109.bjr-2020-0497.r1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
AIMS Accumulated evidence indicates that local cell origins may ingrain differences in the phenotypic activity of human osteoblasts. We hypothesized that these differences may also exist in osteoblasts harvested from the same bone type at periarticular sites, including those adjacent to the fixation sites for total joint implant components. METHODS Human osteoblasts were obtained from the acetabulum and femoral neck of seven patients undergoing total hip arthroplasty (THA) and from the femoral and tibial cuts of six patients undergoing total knee arthroplasty (TKA). Osteoblasts were extracted from the usually discarded bone via enzyme digestion, characterized by flow cytometry, and cultured to passage three before measurement of metabolic activity, collagen production, alkaline phosphatase (ALP) expression, and mineralization. RESULTS Osteoblasts from the acetabulum showed lower proliferation (p = 0.034), cumulative collagen release (p < 0.001), and ALP expression (p = 0.009), and produced less mineral (p = 0.006) than those from the femoral neck. Osteoblasts from the tibia produced significantly less collagen (p = 0.021) and showed lower ALP expression than those from the distal femur. CONCLUSION We have demonstrated for the first time an anatomical regional variation in the biological behaviours of osteoblasts on either side of the hip and knee joint. The lower osteoblast proliferation, matrix production, and mineralization from the acetabulum compared to those from the proximal femur may be reflected in differences in bone formation and implant fixation at these sites. Cite this article: Bone Joint Res 2021;10(9):611-618.
Collapse
Affiliation(s)
- Erden Ali
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
- Erden Ali. E-mail:
| | - Mark Birch
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
| | - Niina Hopper
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
| | - Neil Rushton
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
| | - Andrew W. McCaskie
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
| | - Roger A. Brooks
- Division of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital, Cambridge, UK
| |
Collapse
|
13
|
Preidl RHM, Amann K, Weber M, Schiller M, Ringler M, Ries J, Neukam FW, Kesting M, Geppert CI, Wehrhan F. Lineage-associated connexin 43 expression in bisphosphonate-exposed rat bones. J Craniomaxillofac Surg 2021; 49:738-747. [PMID: 33642117 DOI: 10.1016/j.jcms.2021.02.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 11/19/2020] [Accepted: 02/14/2021] [Indexed: 10/22/2022] Open
Abstract
Expression of signaling proteins in bone cells depends on their embryological mesoderm-derived (e.g. tibia) or cranial neural crest (CNC)-derived (e.g. jaw) origin. Connexin 43 (Cx43) is a gap junction protein that plays an essential role in the mode of action of bisphosphonates (BP). This study aimed to investigate Cx43 expression and the influence of BP application on mesoderm- and CNC-derived bone. Using a rat model, molar extraction and tibia osteotomy with (Group 4) or without (Group 3) previous BP application was performed. Untreated (Group 1) and animals selectively treated with BPs (Group 2) served as controls. Cx43 expression was immunohistochemically determined 12 and 16 weeks postoperatively via a labeling index. Cx43 expression in CNC-derived bone was significantly higher compared with mesodermal bone. BP application decreased Cx43 expression; however, detected expression levels were still higher in jawbone (Group 2 tibia vs jaw: 5.83 ± 5.06 vs 23.52 ± 6.42; p = 0.007). During bone healing after surgical intervention (Group 3) there were no expression differences between tibia and jawbone. BP treatment prior to surgery resulted in significantly lower Cx43 expression in CNC-derived compared with tibia bone (Group 4 tibia vs jaw: 56.84 ± 15.57 vs 16.40 ± 5.66; p < 0.01). Increased Cx43 expression in jaw compared with tibia bone is in line with their embryological origins. A significant Cx43 suppression in jawbone after BP application and surgery might contribute to the selectively altered osseous turnover and development of MRONJ in CNC-derived bone.
Collapse
Affiliation(s)
- Raimund H M Preidl
- Resident, Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany.
| | - Kerstin Amann
- Head of Nephropathology, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Manuel Weber
- Resident, Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Martin Schiller
- Doctoral Students, Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Manuela Ringler
- Doctoral Students, Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Jutta Ries
- Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Friedrich W Neukam
- Former Head of Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Marco Kesting
- Head of Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Carol-Immanuel Geppert
- Specialist in Pathology, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| | - Falk Wehrhan
- Specialist in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstraße 11, 91056, Erlangen, Germany
| |
Collapse
|
14
|
Brown AD, Rafaels KA, Weerasooriya T. Shear behavior of human skull bones. J Mech Behav Biomed Mater 2021; 116:104343. [PMID: 33513459 DOI: 10.1016/j.jmbbm.2021.104343] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 10/16/2020] [Accepted: 01/16/2021] [Indexed: 11/25/2022]
Abstract
A shear-punch test (SPT) experimental method was developed to address the lack of shear deformation and failure response data for the human skull as a function of local bone microarchitecture. Improved understanding of skull deformation and fracture under varying stress-states helps implement mechanism-based, multi-axial material models for finite element analysis for optimizing protection strategies. Shear-punch coupons (N = 47 specimens) were extracted from right-parietal and frontal bones of three fresh-frozen-thawed human skulls. The specimens were kept as full through-thickness or segmented into the three skull constituent layers: the inner and outer cortical tables and the middle porous diploë. Micro-computed x-ray tomography (μCT) before and after SPT provided the bone volume fraction (BVF) as a function of depth for correlation to shear mechanisms in the punched volumes. Digital image correlation was used to track displacement of the punch above the upper die to minimize compliance error. Five full-thickness specimens were subjected to partial indentation loading to investigate the process of damage development as a function of BVF and depth. It was determined that BVF dominates the shear yield and ultimate strength of human skull bone, but the imposed uniaxial loading rate (0.001 and 0.1 s-1) did not have as strong a contribution (p = 0.181-0.806 > 0.05) for the shear yield and ultimate strength of the skull bone layer specimens. Shear yield and ultimate strength data were highly correlated to power law relationships of BVF (R2 = 0.917-0.949). Full-thickness and partial loaded SPT experiments indicate the diploë primarily dictates the shear strength of the intact structure.
Collapse
Affiliation(s)
- A D Brown
- Weapons and Materials Research Directorate, U.S. Army Development Command Army Research Laboratory, Aberdeen Proving Ground, MD, 21005, USA.
| | - K A Rafaels
- Weapons and Materials Research Directorate, U.S. Army Development Command Army Research Laboratory, Aberdeen Proving Ground, MD, 21005, USA
| | - T Weerasooriya
- Weapons and Materials Research Directorate, U.S. Army Development Command Army Research Laboratory, Aberdeen Proving Ground, MD, 21005, USA
| |
Collapse
|
15
|
Lau LY, Nguyen LT, Reverter A, Moore SS, Lynn A, McBride‐Kelly L, Phillips‐Rose L, Plath M, Macfarlane R, Vasudivan V, Morton L, Ardley R, Ye Y, Fortes MRS. Gene regulation could be attributed to TCF3 and other key transcription factors in the muscle of pubertal heifers. Vet Med Sci 2020; 6:695-710. [PMID: 32432381 PMCID: PMC7738712 DOI: 10.1002/vms3.278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 03/13/2020] [Accepted: 04/09/2020] [Indexed: 01/17/2023] Open
Abstract
Puberty is a whole-body event, driven by the hypothalamic integration of peripheral signals such as leptin or IGF-1. In the process of puberty, reproductive development is simultaneous to growth, including muscle growth. To enhance our understanding of muscle function related to puberty, we performed transcriptome analyses of muscle samples from six pre- and six post-pubertal Brahman heifers (Bos indicus). Our aims were to perform differential expression analyses and co-expression analyses to derive a regulatory gene network associate with puberty. As a result, we identified 431 differentially expressed (DEx) transcripts (genes and non-coding RNAs) when comparing pre- to post-pubertal average gene expression. The DEx transcripts were compared with all expressed transcripts in our samples (over 14,000 transcripts) for functional enrichment analyses. The DEx transcripts were associated with "extracellular region," "inflammatory response" and "hormone activity" (adjusted p < .05). Inflammatory response for muscle regeneration is a necessary aspect of muscle growth, which is accelerated during puberty. The term "hormone activity" may signal genes that respond to progesterone signalling in the muscle, as the presence of this hormone is an important difference between pre- and post-pubertal heifers in our experimental design. The DEx transcript with the highest average expression difference was a mitochondrial gene, ENSBTAG00000043574 that might be another important link between energy metabolism and puberty. In the derived co-expression gene network, we identified six hub genes: CDC5L, MYC, TCF3, RUNX2, ATF2 and CREB1. In the same network, 48 key regulators of DEx transcripts were identified, using a regulatory impact factor metric. The hub gene TCF3 was also a key regulator. The majority of the key regulators (22 genes) are members of the zinc finger family, which has been implicated in bovine puberty in other tissues. In conclusion, we described how puberty may affect muscle gene expression in cattle.
Collapse
Affiliation(s)
- Li Yieng Lau
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Loan T. Nguyen
- Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandBrisbaneQLDAustralia
| | - Antonio Reverter
- CSIRO Agriculture and FoodQueensland Biosciences PrecinctBrisbaneQLDAustralia
| | - Stephen S. Moore
- Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandBrisbaneQLDAustralia
| | - Aaron Lynn
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Liam McBride‐Kelly
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Louis Phillips‐Rose
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Mackenzie Plath
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Rhys Macfarlane
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Vanisha Vasudivan
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Lachlan Morton
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Ryan Ardley
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Yunan Ye
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
| | - Marina R. S. Fortes
- School of Chemistry and Molecular BiologyThe University of QueenslandBrisbaneQLDAustralia
- Queensland Alliance for Agriculture and Food InnovationThe University of QueenslandBrisbaneQLDAustralia
| |
Collapse
|
16
|
Shah FA, Ruscsák K, Palmquist A. Transformation of bone mineral morphology: From discrete marquise-shaped motifs to a continuous interwoven mesh. Bone Rep 2020; 13:100283. [PMID: 32577436 PMCID: PMC7305389 DOI: 10.1016/j.bonr.2020.100283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 05/17/2020] [Indexed: 12/24/2022] Open
Abstract
Continual bone apposition at the cranial sutures provides the unique opportunity to understand how bone is built. Bone harvested from 16-week-old Sprague Dawley rat calvaria was either (i) deproteinised to isolate the inorganic phase (i.e., bone mineral) for secondary electron scanning electron microscopy or (ii) resin embedded for X-ray micro-computed tomography, backscattered electron scanning electron microscopy, and micro-Raman spectroscopy. Interdigitated finger-like projections form the interface between frontal and parietal bones. Viewed from the surface, bone mineral at the mineralisation front is comprised of nanoscale mineral platelets arranged into discrete, ~0.6–3.5 μm high and ~0.2–1.5 μm wide, marquise-shaped motifs that gradually evolve into a continuous interwoven mesh of mineralised bundles. Marquise-shaped motifs also contribute to the burial of osteoblastic–osteocytes by contributing to the roof over the lacunae. In cross-section, apices of the finger-like projections resemble islands of mineralised tissue, where new bone apposition at the surface is evident as low mineral density areas, while the marquise-shaped motifs appear as near-equiaxed assemblies of mineral platelets. Carbonated apatite content is higher towards the internal surface of the cranial vault. Up to 4 μm from the bone surface, strong Amide III, Pro, Hyp, and Phe signals, distinct PO43− bands, but negligible CO32– signal indicate recent bone formation and/or delayed maturation of the mineral. We show, for the first time, that the extracellular matrix of bone is assembled into micrometre-sized units, revealing a superstructure above the mineralised collagen fibril level, which has significant implications for function and mechanical competence of bone. The mineralisation front at cranial sutures of 16-week-old rats was investigated Interdigitated finger-like projections extend between frontal and parietal bones Micrometre-sized, marquise-shaped motifs of bone apatite at the mineralisation front Distinct motifs evolve into interwoven mesh of mineralised bundles Cranial bones are more mineralised at the internal surface (towards the dura mater)
Collapse
Affiliation(s)
- Furqan A Shah
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Krisztina Ruscsák
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Palmquist
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
17
|
Wang N, Niger C, Li N, Richards GO, Skerry TM. Cross-Species RNA-Seq Study Comparing Transcriptomes of Enriched Osteocyte Populations in the Tibia and Skull. Front Endocrinol (Lausanne) 2020; 11:581002. [PMID: 33071985 PMCID: PMC7543096 DOI: 10.3389/fendo.2020.581002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/21/2020] [Indexed: 12/17/2022] Open
Abstract
Local site-specific differences between bones in different regions of the skeleton account for their different properties and functions. To identify mechanisms behind these differences, we have performed a cross-species study comparing RNA transcriptomes of cranial and tibial osteocytes, from bones with very different primary functions and physiological responses, collected from the same individual mouse, rat, and rhesus macaque. Bioinformatic analysis was performed to identify 32 genes changed in the same direction between sites and shared across all three species. Several well-established key genes in bone growth and remodeling were upregulated in the tibias of all three species (BMP7, DKK1, FGF1, FRZB, SOST). Many of them associate or crosstalk with the Wnt signaling pathway. These results suggest Wnt signaling-related candidates for different control of regulatory mechanisms in bone homeostasis in the skull and tibia and indicate a different balance between genetically determined structure and feedback mechanisms to strains induced by mechanical loading at the different sites.
Collapse
Affiliation(s)
- Ning Wang
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Corinne Niger
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Nan Li
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Gareth O. Richards
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
| | - Tim M. Skerry
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield, United Kingdom
- *Correspondence: Tim M. Skerry
| |
Collapse
|
18
|
Hollensteiner M, Augat P, Fürst D, Schrödl F, Esterer B, Gabauer S, Schrempf A. Bone surrogates provide authentic onlay graft fixation torques. J Mech Behav Biomed Mater 2018; 91:159-163. [PMID: 30580158 DOI: 10.1016/j.jmbbm.2018.12.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/11/2018] [Accepted: 12/13/2018] [Indexed: 10/27/2022]
Abstract
Onlay graft bone augmentation is a standard practice to restore the loss of height of the alveolar ridge following loss of a tooth. Cranial grafts, lifted from the parietal bone, are sandwiched and used to bridge the bony defect in the jaw by means of small screws. During the elevation of the covering gum and subsequent screw placement, care has to be taken in order to preserve underlying nerves. Therefore, to avoid harm to the patient, a solid education of surgeons is essential, which requires training and experience. A simulator for cranial graft-lift training was already developed and shall be expanded to train the augmentation of the lifted implants. Therefore, in this study, synthetic bones for onlay block graft screw placement with realistic haptics for the screw application training were evaluated and compared with human specimens. Six different polyurethane based bone surrogate composites, enriched with varying amounts of calcium-based mineral fillers and blowing agents, were developed. The haptical properties of these synthetic bones were validated for screw placement and compared with human parietal bone specimens. For that, bones were pre-drilled, screws were automatically inserted using a customized testbench and the slope of the screw-insertion torques were analyzed. The slope of the screw insertion torques of the human reference bones was 56.5 ± 14.0 * 10-3 Nm/deg, Surrogates with lower amounts of mineral fillers and blowing agents showed lower torques than the human bone. Synthetic bones, validated for drilling, milling and sawing in an earlier study, also achieved significantly lower torques, which were only the half of the human parietal bones. Two intermediate stages of the aforementioned material compositions, consisting of 75% mineral filler with 0.75% blowing agent and 100% mineral filler with 1.00% blowing agent revealed results comparable with human bone (57.4 ± 10.2 *10-3 Nm/deg, p = 0.893 and 54.9 ± 11.1 *10-3 Nm/deg, p = 0.795, respectively). In conclusion, our findings suggest that, two newly developed polyurethane-based materials mimicking the haptical properties of an onlay bone graft screw fixation, have been identified. Thus, these surrogates are capable of mimicking real bone tissue in our simulator for the education of novice surgeons.
Collapse
Affiliation(s)
- Marianne Hollensteiner
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Garnisonstr.21, 4020 Linz, Austria; Institute of Biomechanics, BG Unfallklinik Murnau, Germany and Paracelsus Medical University Salzburg, Prof. Küntscher Str. 8, 82418 Murnau am Staffelsee, Germany.
| | - Peter Augat
- Institute of Biomechanics, BG Unfallklinik Murnau, Germany and Paracelsus Medical University Salzburg, Prof. Küntscher Str. 8, 82418 Murnau am Staffelsee, Germany
| | - David Fürst
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Garnisonstr.21, 4020 Linz, Austria
| | - Falk Schrödl
- Institute of Anatomy, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria
| | - Benjamin Esterer
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Garnisonstr.21, 4020 Linz, Austria; Institute of Biomechanics, BG Unfallklinik Murnau, Germany and Paracelsus Medical University Salzburg, Prof. Küntscher Str. 8, 82418 Murnau am Staffelsee, Germany
| | - Stefan Gabauer
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Garnisonstr.21, 4020 Linz, Austria
| | - Andreas Schrempf
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, School of Applied Health and Social Sciences, Garnisonstr.21, 4020 Linz, Austria
| |
Collapse
|
19
|
Gharibi B, Ghuman MS, Cama G, Rawlinson SCF, Grigoriadis AE, Hughes FJ. Site-specific differences in osteoblast phenotype, mechanical loading response and estrogen receptor-related gene expression. Mol Cell Endocrinol 2018; 477:140-147. [PMID: 29928929 DOI: 10.1016/j.mce.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 05/08/2018] [Accepted: 06/16/2018] [Indexed: 12/23/2022]
Abstract
The osteoporosis-resistant nature of skull bones implies inherent differences exist between their cellular responses and those of other osteoporosis-susceptible skeletal sites. Phenotypic differences in calvarial and femoral osteoblastic responses to induction of osteogenesis, mechanical loading, estrogen, growth factor and cytokine stimulation were investigated. Primary rat calvarial and femoral adult male osteoblasts were cultured and osteoblastic mineralisation and maturation determined using Alizarin Red staining and expression of osteogenic marker genes assessed. Expression of known mechanically-responsive genes was compared between sites following loading of scaffold-seeded cells in a bioreactor. Cell proliferation and differentiation following growth factor and estrogen stimulation were also compared. Finally expression of estrogen receptors and associated genes during osteogenic differentiation were investigated. Calvarial osteoblasts exhibited delayed maturation (45d. vs 21d.) and produced less mineralised matrix than femoral osteoblasts when osteogenically induced. PDGF-BB and FGF2 both caused a selective increase in proliferation and decrease in osteoblastic differentiation of femoral osteoblasts. Mechanical stimulation resulted in the induction of the expression of Ccl2 and Anx2a selectively in femoral osteoblasts, but remained unchanged in calvarial cells. Estrogen receptor beta expression was selectively upregulated 2-fold in calvarial osteoblasts. Most interestingly, the estrogen responsive transcriptional repressor RERG was constitutively expressed at 1000-fold greater levels in calvarial compared with femoral osteoblasts. RERG expression in calvarial osteoblasts was down regulated during osteogenic induction whereas upregulation occurred in femoral osteoblasts. Bone cells of the skull are inherently different to those of the femur, and respond differentially to a range of stimuli. These site-specific differences may have important relevance in the development of strategies to tackle metabolic bone disorders.
Collapse
Affiliation(s)
- Borzo Gharibi
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK.
| | - Mandeep S Ghuman
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Giuseppe Cama
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Simon C F Rawlinson
- Centre for Oral Growth and Development, Institute of Dentistry, Queen Mary University of London, New Road, London, E1 2BA, UK
| | - Agamemnon E Grigoriadis
- Centre for Craniofacial and Regenerative Biology, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK
| | - Francis J Hughes
- Division of Tissue Engineering and Biophotonics, Dental Institute, King's College London, Tower Wing, Guy's Hospital, London, SE1 9RT, UK.
| |
Collapse
|
20
|
Hollensteiner M, Fürst D, Augat P, Schrödl F, Esterer B, Gabauer S, Hunger S, Malek M, Stephan D, Schrempf A. Characterization of an artificial skull cap for cranio-maxillofacial surgery training. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:135. [PMID: 30120585 PMCID: PMC6105196 DOI: 10.1007/s10856-018-6143-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Cranial grafts are favored to reconstruct skeletal defects because of their reduced resorption and their histocompatibility. Training possibilities for novice surgeons include the "learning by doing" on the patient, specimens or simulators. Although the acceptance of simulators is growing, the major drawback is the lack of validated bone models. The aim of this study was to create and validate a realistic skull cap model and to show superiority compared to a commercially available skull model. Characteristic forces during machinery procedures were recorded and thickness parameters from the bony layers were obtained. The thickness values of the bone layers of the developed parietal bone were comparable to the human ones. Differences between drilling and sawing forces of human and artificial bones were not detected using statistical analysis. In contrast the parameters of the commercially available skull model were significantly different. However, as a result, a model-based simulator for tabula externa graft lift training, consisting of a brain, skull bone cap and covering soft tissues was created. This simulator enables the training of all procedural steps of a "split thickness graft lift". In conclusion, an artificial skull cap suitable for parietal graft lift training was manufactured and validated against human parietal bones.
Collapse
Affiliation(s)
- Marianne Hollensteiner
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria.
- Institue of Biomechanics, Berufsgenossenschaftliche Unfallklinik Murnau and Paracelsus Medical University Salzburg, Murnau, Germany.
| | - David Fürst
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
| | - Peter Augat
- Institue of Biomechanics, Berufsgenossenschaftliche Unfallklinik Murnau and Paracelsus Medical University Salzburg, Murnau, Germany
| | - Falk Schrödl
- Institute of Anatomy, Paracelsus Medical University, Salzburg, Austria
| | - Benjamin Esterer
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
- Institue of Biomechanics, Berufsgenossenschaftliche Unfallklinik Murnau and Paracelsus Medical University Salzburg, Murnau, Germany
| | - Stefan Gabauer
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
| | - Stefan Hunger
- Department for Oral and Maxillofacial Surgery, Kepler University Hospital, Med Campus III, Linz, Austria
| | - Michael Malek
- Department for Oral and Maxillofacial Surgery, Kepler University Hospital, Med Campus III, Linz, Austria
| | | | - Andreas Schrempf
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
| |
Collapse
|
21
|
Javaheri B, Caetano-Silva SP, Kanakis I, Bou-Gharios G, Pitsillides AA. The Chondro-Osseous Continuum: Is It Possible to Unlock the Potential Assigned Within? Front Bioeng Biotechnol 2018; 6:28. [PMID: 29619368 PMCID: PMC5871702 DOI: 10.3389/fbioe.2018.00028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 01/08/2023] Open
Abstract
Endochondral ossification (EO), by which long bones of the axial skeleton form, is a tightly regulated process involving chondrocyte maturation with successive stages of proliferation, maturation, and hypertrophy, accompanied by cartilage matrix synthesis, calcification, and angiogenesis, followed by osteoblast-mediated ossification. This developmental sequence reappears during fracture repair and in osteoarthritic etiopathology. These similarities suggest that EO, and the cells involved, are of great clinical importance for bone regeneration as it could provide novel targeted approaches to increase specific signaling to promote fracture healing, and if regulated appropriately in the treatment of osteoarthritis. The long-held accepted dogma states that hypertrophic chondrocytes are terminally differentiated and will eventually undergo apoptosis. In this mini review, we will explore recent evidence from experiments that revisit the idea that hypertrophic chondrocytes have pluripotent capacity and may instead transdifferentiate into a specific sub-population of osteoblast cells. There are multiple lines of evidence, including our own, showing that local, selective alterations in cartilage extracellular matrix (ECM) remodeling also indelibly alter bone quality. This would be consistent with the hypothesis that osteoblast behavior in long bones is regulated by a combination of their lineage origins and the epigenetic effects of chondrocyte-derived ECM which they encounter during their recruitment. Further exploration of these processes could help to unlock potential novel targets for bone repair and regeneration and in the treatment of osteoarthritis.
Collapse
Affiliation(s)
- Behzad Javaheri
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| | - Soraia P Caetano-Silva
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| | - Ioannis Kanakis
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - George Bou-Gharios
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Andrew A Pitsillides
- Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
| |
Collapse
|
22
|
Suswillo RFL, Javaheri B, Rawlinson SCF, Dowthwaite GP, Lanyon LE, Pitsillides AA. Strain uses gap junctions to reverse stimulation of osteoblast proliferation by osteocytes. Cell Biochem Funct 2017; 35:56-65. [PMID: 28083967 PMCID: PMC5299599 DOI: 10.1002/cbf.3245] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/01/2016] [Accepted: 11/29/2016] [Indexed: 12/20/2022]
Abstract
Identifying mechanisms by which cells of the osteoblastic lineage communicate in vivo is complicated by the mineralised matrix that encases osteocytes, and thus, vital mechanoadaptive processes used to achieve load-bearing integrity remain unresolved. We have used the coculture of immunomagnetically purified osteocytes and primary osteoblasts from both embryonic chick long bone and calvariae to examine these mechanisms. We exploited the fact that purified osteocytes are postmitotic to examine both their effect on proliferation of primary osteoblasts and the role of gap junctions in such communication. We found that chick long bone osteocytes significantly increased basal proliferation of primary osteoblasts derived from an identical source (tibiotarsi). Using a gap junction inhibitor, 18β-glycyrrhetinic acid, we also demonstrated that this osteocyte-related increase in osteoblast proliferation was not reliant on functional gap junctions. In contrast, osteocytes purified from calvarial bone failed to modify basal proliferation of primary osteoblast, but long bone osteocytes preserved their proproliferative action upon calvarial-derived primary osteoblasts. We also showed that coincubated purified osteocytes exerted a marked inhibitory action on mechanical strain-related increases in proliferation of primary osteoblasts and that this action was abrogated in the presence of a gap junction inhibitor. These data reveal regulatory differences between purified osteocytes derived from functionally distinct bones and provide evidence for 2 mechanisms by which purified osteocytes communicate with primary osteoblasts to coordinate their activity.
Collapse
Affiliation(s)
| | - Behzad Javaheri
- Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Simon C F Rawlinson
- Institute of Dentistry, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Gary P Dowthwaite
- Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Lance E Lanyon
- School of Veterinary Sciences, University of Bristol, Bristol, UK
| | | |
Collapse
|
23
|
Rees CL, White CM, Ascoli GA. Neurochemical Markers in the Mammalian Brain: Structure, Roles in Synaptic Communication, and Pharmacological Relevance. Curr Med Chem 2017; 24:3077-3103. [PMID: 28413962 PMCID: PMC5646670 DOI: 10.2174/0929867324666170414163506] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/15/2017] [Accepted: 04/10/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Knowledge of molecular marker (typically protein or mRNA) expression in neural systems can provide insight to the chemical blueprint of signal processing and transmission, assist in tracking developmental or pathological progressions, and yield key information regarding potential medicinal targets. These markers are particularly relevant in the mammalian brain in the light of its unsurpassed cellular diversity. Accordingly, molecular expression profiling is rapidly becoming a major approach to classify neuron types. Despite a profusion of research, however, the biological functions of molecular markers commonly used to distinguish neuron types remain incompletely understood. Furthermore, most molecular markers of mammalian neuron types are also present in other organs, therefore complicating considerations of their potential pharmacological interactions. OBJECTIVE Here, we survey 15 prominent neurochemical markers from five categories, namely membrane transporters, calcium-binding proteins, neuropeptides, receptors, and extracellular matrix proteins, explaining their relation and relevance to synaptic communication. METHOD For each marker, we summarize fundamental structural features, cellular functionality, distributions within and outside the brain, as well as known drug effectors and mechanisms of action. CONCLUSION This essential primer thus links together the cellular complexity of the brain, the chemical properties of key molecular players in neurotransmission, and possible biomedical opportunities.
Collapse
Affiliation(s)
- Christopher L. Rees
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Charise M. White
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Giorgio A. Ascoli
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| |
Collapse
|
24
|
Khialeeva E, Carpenter EM. Nonneuronal roles for the reelin signaling pathway. Dev Dyn 2016; 246:217-226. [PMID: 27739126 DOI: 10.1002/dvdy.24462] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/09/2016] [Accepted: 10/10/2016] [Indexed: 12/21/2022] Open
Abstract
The reelin signaling pathway has been established as an important regulator of cell migration during development of the central nervous system, and disruptions in reelin signaling alter the positioning of many types of neurons. Reelin is a large extracellular matrix glycoprotein and governs cell migration through activation of multiple intracellular signaling events by means of the receptors ApoE receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR), and the intracellular adaptor protein Disabled-1 (Dab1). Earlier studies reported expression of reelin in nonneuronal tissues, but the functions of this signaling pathway outside of the nervous system have not been studied until recently. A large body of evidence now suggests that reelin functions during development and disease of multiple nonneuronal tissues. This review addresses recent advances in the field of nonneuronal reelin signaling. Developmental Dynamics 246:217-226, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Elvira Khialeeva
- Molecular Biology Interdepartmental Program, University of California Los Angeles, Los Angeles, California
| | - Ellen M Carpenter
- Department of Psychiatry and Biobehavioral Science, University of California Los Angeles School of Medicine, Los Angeles, California
| |
Collapse
|
25
|
Clarke MS, Plouznikoff A, Deschênes J. The asymmetric protein expression hypothesis - Explaining the unilaterality of HLA-B27-positive acute anterior uveitides. Med Hypotheses 2016; 88:10-1. [PMID: 26880626 DOI: 10.1016/j.mehy.2015.12.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 12/29/2015] [Indexed: 11/27/2022]
Abstract
For reasons still unclear, most HLA-B27-positive acute anterior uveitides occur unilaterally. Building upon the growing literature showing that left-right asymmetry exist at the biomolecular and at the cellular levels, we propose a new hypothesis to explain why HLA-B27-positive acute anterior uveitides tend to affect one eye selectively. We postulate that left and right uveal tissue may present quantitatively and qualitatively different proteins to the immune system, capable to trigger an autoimmune response, and that other variables, including anatomical, cellular and molecular barriers, as well as our own eye-derived immunological tolerance and immune suppressive intraocular microenvironment may also be unequally distributed, and impact differently the immune privileges of the left and right eye. These same quantitative and qualitative differences might also explain why HLA-B27-positive acute anterior uveitides can flip-flop between the left and the right eye, after the first attack. By trying to figure out why one eye is targeted by an autoimmune reaction while the other is clinically unaffected, we might be able to better understand how and why an autoimmune reaction starts. Hopefully, this will help us devise better treatments for ocular autoimmune diseases, and contribute to the management of autoinflammatory conditions with a marked asymmetric clinical presentation in other fields.
Collapse
Affiliation(s)
- Margo S Clarke
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada.
| | | | - Jean Deschênes
- Department of Ophthalmology, McGill University, Montreal, QC, Canada
| |
Collapse
|
26
|
Stachewicz U, Qiao T, Rawlinson SCF, Almeida FV, Li WQ, Cattell M, Barber AH. 3D imaging of cell interactions with electrospun PLGA nanofiber membranes for bone regeneration. Acta Biomater 2015; 27:88-100. [PMID: 26348143 DOI: 10.1016/j.actbio.2015.09.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/02/2015] [Accepted: 09/04/2015] [Indexed: 11/15/2022]
Abstract
The interaction between resident cells and electrospun nanofibers is critical in determining resultant osteoblast proliferation and activity in orthopedic tissue scaffolds. The use of techniques to evaluate cell-nanofiber interactions is critical in understanding scaffold function, with visualization promising unparalleled access to spatial information on such interactions. 3D tomography exploiting focused ion beam (FIB)-scanning electron microscopy (SEM) was used to examine electrospun nanofiber scaffolds to understand the features responsible for (osteoblast-like MC3T3-E1 and UMR106) cell behavior and resultant scaffold function. 3D imaging of cell-nanofiber interactions within a range of electrospun poly(d,l-lactide-co-glycolide acid) (PLGA) nanofiber scaffold architectures indicated a coherent interface between osteoblasts and nanofiber surfaces, promoting osteoblast filopodia formation for successful cell growth. Coherent cell-nanofiber interfaces were demonstrated throughout a randomly organized and aligned nanofiber network. Gene expression of UMR106 cells grown on PLGA fibers did not deviate significantly from those grown on plastic, suggesting maintenance of phenotype. However, considerably lower expression of Ibsp and Alpl on PLGA fibers might indicate that these cells are still in the proliferative phase compared with a more differentiated cell on plastic. This work demonstrates the synergy between designing electrospun tissue scaffolds and providing comprehensive evaluation through high resolution imaging of resultant 3-dimensional cell growth within the scaffold. STATEMENT OF SIGNIFICANCE Membranes made from electrospun nanofibers are potentially excellent for promoting bone growth for next-generation tissue scaffolds. The effectiveness of an electrospun membrane is shown here using high resolution 3D imaging to visualize the interaction between cells and the nanofibers within the membrane. Nanofibers that are aligned in one direction control cell growth at the surface of the membrane whereas random nanofibers cause cell growth into the membrane. Such observations are important and indicate that lateral cell growth at the membrane surface using aligned nanofibers could be used for rapid tissue repair whereas slower but more extensive tissue production is promoted by membranes containing random nanofibers.
Collapse
Affiliation(s)
- Urszula Stachewicz
- Nanoforce Technology Ltd., Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom; School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom; AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science and Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków, Poland.
| | - Tuya Qiao
- School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom.
| | - Simon C F Rawlinson
- Research Centre for Oral Growth and Development, Barts and The London, Queen Mary's School of Medicine and Dentistry, Queen Mary, University of London, 4 Newark Street, London E1 2AT, United Kingdom.
| | - Filipe Veiga Almeida
- School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom.
| | - Wei-Qi Li
- School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom.
| | - Michael Cattell
- Centre for Adult Oral Health, Institute of Dentistry, Barts and The London, Queen Mary's School of Medicine and Dentistry, Queen Mary, University of London, Turner Street, Whitechapel E1 2AD, United Kingdom.
| | - Asa H Barber
- Nanoforce Technology Ltd., Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom; School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom; School of Engineering, University of Portsmouth, Portsmouth PO1 3DJ, United Kingdom.
| |
Collapse
|
27
|
Tower RJ, Campbell GM, Müller M, Glüer CC, Tiwari S. Utilizing time-lapse micro-CT-correlated bisphosphonate binding kinetics and soft tissue-derived input functions to differentiate site-specific changes in bone metabolism in vivo. Bone 2015; 74:171-81. [PMID: 25613175 DOI: 10.1016/j.bone.2015.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 11/18/2022]
Abstract
The turnover of bone is a tightly regulated process between bone formation and resorption to ensure skeletal homeostasis. This process differs between bone types, with trabecular bone often associated with higher turnover than cortical bone. Analyses of bone by micro-computed tomography (micro-CT) reveal changes in structure and mineral content, but are limited in the study of metabolic activity at a single time point, while analyses of serum markers can reveal changes in bone metabolism, but cannot delineate the origin of any aberrant findings. To obtain a site-specific assessment of bone metabolic status, bisphosphonate binding kinetics were utilized. Using a fluorescently-labeled bisphosphonate, we show that early binding kinetics monitored in vivo using fluorescent molecular tomography (FMT) can monitor changes in bone metabolism in response to bone loss, stimulated by ovariectomy (OVX), or bone gain, resulting from treatment with the anabolic bone agent parathyroid hormone (PTH), and is capable of distinguishing different, metabolically distinct skeletal sites. Using time-lapse micro-CT, longitudinal bone turnover was quantified. The spine showed a significantly greater percent resorbing volume and surface in response to OVX, while mice treated with PTH showed significantly greater resorbing volume per bone surface in the spine and significantly greater forming surfaces in the knee. Correlation studies between binding kinetics and micro-CT suggest that forming surfaces, as assessed by time-lapse micro-CT, are preferentially reflected in the rate constant values while forming and resorbing bone volumes primarily affect plateau values. Additionally, we developed a blood pool correction method which now allows for quantitative multi-compartment analyses to be conducted using FMT. These results further expand our understanding of bisphosphonate binding and the use of bisphosphonate binding kinetics as a tool to monitor site-specific changes in bone metabolism in vivo.
Collapse
Affiliation(s)
- R J Tower
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - G M Campbell
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - M Müller
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - C C Glüer
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - S Tiwari
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
| |
Collapse
|
28
|
Du Z, Lee RSB, Hamlet S, Doan N, Ivanovski S, Xiao Y. Evaluation of the first maxillary molar post-extraction socket as a model for dental implant osseointegration research. Clin Oral Implants Res 2015; 27:1469-1478. [DOI: 10.1111/clr.12571] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2015] [Indexed: 12/01/2022]
Affiliation(s)
- Zhibin Du
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Kelvin Grove Brisbane Qld Australia
| | - Ryan S. B. Lee
- School of Dentistry and Oral Health; Griffith University; Southport Qld Australia
| | - Stephen Hamlet
- School of Dentistry and Oral Health; Griffith University; Southport Qld Australia
| | - Nghiem Doan
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Kelvin Grove Brisbane Qld Australia
| | - Saso Ivanovski
- School of Dentistry and Oral Health; Griffith University; Southport Qld Australia
| | - Yin Xiao
- Institute of Health and Biomedical Innovation; Queensland University of Technology; Kelvin Grove Brisbane Qld Australia
| |
Collapse
|
29
|
Galea GL, Price JS. Four-point bending protocols to study the effects of dynamic strain in osteoblastic cells in vitro. Methods Mol Biol 2015; 1226:117-130. [PMID: 25331047 DOI: 10.1007/978-1-4939-1619-1_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Strain engendered within bone tissue by mechanical loading of the skeleton is a major influence on the processes of bone modeling and remodeling and so a critical determinant of bone mass and architecture. The cells best placed to respond to strain in bone tissue are the resident osteocytes and osteoblasts. To address the mechanisms of strain-related responses in osteoblast-like cells, our group uses both in vivo and in vitro approaches, including a system of four-point bending of the substrate on which cells are cultured. A range of cell lines can be studied using this system but we routinely compare their responses to those in primary cultures of osteoblast-like cells derived from explants of mouse long bones. These cells show a range of well-characterized responses to physiological levels of strain, including increased proliferation, which in vivo is a feature of the osteogenic response.
Collapse
Affiliation(s)
- Gabriel L Galea
- School of Veterinary Sciences, University of Bristol, Southwell Str, Bristol, BS2 8EJ, UK
| | | |
Collapse
|
30
|
Du Z, Steck R, Doan N, Woodruff MA, Ivanovski S, Xiao Y. Estrogen Deficiency-Associated Bone Loss in the Maxilla: A Methodology to Quantify the Changes in the Maxillary Intra-radicular Alveolar Bone in an Ovariectomized Rat Osteoporosis Model. Tissue Eng Part C Methods 2014; 21:458-66. [PMID: 25315176 DOI: 10.1089/ten.tec.2014.0268] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The effects of estrogen deficiency on bone characteristics are site-dependent, with the most commonly studied sites being appendicular long bones (proximal femur and tibia) and axial bones (vertebra). The effect on the maxillary and mandibular bones is still inconsistent and requires further investigation. This study was designed to evaluate bone quality in the posterior maxilla of ovariectomized rats to validate this site as an appropriate model to study the effect of osteoporotic changes. Forty-eight 3-month-old female Sprague-Dawley rats were randomly divided into two groups: an ovariectomized (OVX) group (n=24) and Sham-operated (SHAM) group (n=24). Six rats were randomly sacrificed from both groups at time points 8, 12, 16, and 20 weeks. The samples from tibia and maxilla were collected for micro computed tomography (μCT) and histological analysis. For the maxilla, the volume of interest area focused on the furcation areas of the first and second molar. Trabecular bone volume fraction (BV/TV, %), trabecular thickness (Tb.Th.), trabecular number (Tb.N.), trabecular separation (Tb.Sp.), and connectivity density (Conn.Dens) were analyzed after Micro CT scanning. At 8 weeks the indices BV/TV, Tb.Sp., Tb.N., and Conn.Dens showed significant differences (p<0.05) between the OVX and SHAM groups in the tibia. Compared with the tibia, the maxilla developed osteoporosis at a later stage, with significant changes in maxillary bone density only occurring after 12 weeks. Compared with the SHAM group, both the first and second molars of the OVX group showed significantly decreased BV/TV values from 12 weeks, and these changes were sustained through 16 and 20 weeks. For Tb.Sp., there were significant increases in bone values for the OVX group compared with the SHAM group at 12, 16, and 20 weeks. Histological changes were highly consistent with Micro CT results. This study established a method to quantify the changes of intra-radicular alveolar bone in the posterior maxilla in an accepted rat osteoporosis model. The degree of the osteoporotic changes to trabecular bone architecture is site-dependent and at least 3 months are required for the osteoporotic effects to be apparent in the posterior maxilla following rat OVX.
Collapse
Affiliation(s)
- Zhibin Du
- 1 Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane, Queensland, Australia
| | | | | | | | | | | |
Collapse
|
31
|
BRONJ-related jaw bone is associated with increased Dlx-5 and suppressed osteopontin-implication in the site-specific alteration of angiogenesis and bone turnover by bisphosphonates. Clin Oral Investig 2014; 19:1289-98. [PMID: 25467232 DOI: 10.1007/s00784-014-1354-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 11/04/2014] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Site-specific suppression of bone remodelling has been implicated in bisphosphonate-(BP)-related osteonecrosis of the jaws (BRONJ). Due to the origin of jaw bone from cranial neural crest, osseous differentiation is regulated specifically by the antagonizing BMP-2-downstream-transcription factors Msx-1 and Dlx-5. Osteopontin has been implicated in bone remodelling and angiogenesis. The osteoblast and osteoclast progenitor proliferation mediating Msx-1 has been demonstrated to be suppressed in BRONJ. In vitro BPs were shown to increase Dlx-5 and to suppress osteopontin expression. This study targeted Dlx-5 and osteopontin in BRONJ-related and BP-exposed jaw bone compared with healthy jaw bone samples at protein- and messenger RNA (mRNA) level, since increased Dlx-5 and suppressed osteopontin might account for impaired bone turnover in BRONJ. MATERIALS AND METHODS Fifteen BRONJ-exposed, 15 BP-exposed and 20 healthy jaw bone samples were processed for real-time reverse transcription polymerase chain reaction (RT-PCR) and for immunohistochemistry. Targeting Dlx-5, osteopontin and glyceraldehyde 3-phosphate dehydrogenase mRNA was extracted, quantified by the LabChip-method, followed by quantitative RT-PCR. For immunohistochemistry, an autostaining-based alkaline phosphatase antialkaline phosphatase (APAPP) staining kit was used. Semiquantitative assessment was performed measuring the ratio of stained cells/total number of cells (labelling index, Bonferroni adjustment). RESULTS The labelling index was significant decreased for osteopontin (p < 0.017) and significantly increased for Dlx-5 (p < 0.021) in BRONJ samples. In BRONJ specimens, a significant fivefold decrease in gene expression for osteopontin (p < 0.015) and a significant eightfold increase in Dlx-5 expression (p < 0.012) were found. CONCLUSIONS BRONJ-related suppression of bone turnover is consistent with increased Dlx-5 expression and with suppression of osteopontin. The BP-related impaired BMP-2-Msx-1-Dlx-5 axis might explain the jaw bone specific alteration by BP. CLINICAL RELEVANCE The findings of this study help to explain the restriction of RONJ to craniofacial bones. BRONJ might serve as a model of disease elucidating the specific signal transduction of neural crest cell-derived bone structures in health and disease.
Collapse
|
32
|
Jacques J, Hotton D, Asselin A, De la Dure-Molla M, Coudert AE, Isaac J, Berdal A. Ameloblastin as a putative marker of specific bone compartments. Connect Tissue Res 2014; 55 Suppl 1:117-20. [PMID: 25158194 DOI: 10.3109/03008207.2014.923849] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ameloblastin (AMBN), a member of the enamel matrix protein family, has been recently identified as integral part of the skeleton beyond the enamel. However, the specific role of endogenous AMBN in bone tissue is not fully elucidated. This study aims at investigating mRNA expression of AMBN in wild-type mice in different bone sites from early embryonic to adult stages. AMBN mRNA expression started at pre-dental stages in mouse embryos (E10.5) in both head and body parts. Using laser capture microdissection on 3-day-old mice, we showed an unambiguous mRNA expression of AMBN in extra-dental tissue (mandible bone). Screening of AMBN mRNA expression in adult mice (15-week-old) revealed that mRNA expression of AMBN varied according to the bone site; a higher mRNA levels in mandibular and frontal bone compartments were observed when compared to tibia and occipital bones. These results strongly suggest that AMBN expression may be regulated in a site-specific manner and identify AMBN as a putative in vivo marker of the site-specific fingerprint of bone organs.
Collapse
Affiliation(s)
- Jaime Jacques
- Laboratory of Molecular Oral Pathophysiology, INSERM UMRS 1138, Team Berdal, Cordeliers Research Center, Pierre and Marie Curie University - Paris 6, Paris Descartes University - Paris 5 , Paris , France
| | | | | | | | | | | | | |
Collapse
|
33
|
Isaac J, Erthal J, Gordon J, Duverger O, Sun HW, Lichtler AC, Stein GS, Lian JB, Morasso MI. DLX3 regulates bone mass by targeting genes supporting osteoblast differentiation and mineral homeostasis in vivo. Cell Death Differ 2014; 21:1365-76. [PMID: 24948010 DOI: 10.1038/cdd.2014.82] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 04/25/2014] [Accepted: 05/07/2014] [Indexed: 01/23/2023] Open
Abstract
Human mutations and in vitro studies indicate that DLX3 has a crucial function in bone development, however, the in vivo role of DLX3 in endochondral ossification has not been established. Here, we identify DLX3 as a central attenuator of adult bone mass in the appendicular skeleton. Dynamic bone formation, histologic and micro-computed tomography analyses demonstrate that in vivo DLX3 conditional loss of function in mesenchymal cells (Prx1-Cre) and osteoblasts (OCN-Cre) results in increased bone mass accrual observed as early as 2 weeks that remains elevated throughout the lifespan owing to increased osteoblast activity and increased expression of bone matrix genes. Dlx3OCN-conditional knockout mice have more trabeculae that extend deeper in the medullary cavity and thicker cortical bone with an increased mineral apposition rate, decreased bone mineral density and increased cortical porosity. Trabecular TRAP staining and site-specific Q-PCR demonstrated that osteoclastic resorption remained normal on trabecular bone, whereas cortical bone exhibited altered osteoclast patterning on the periosteal surface associated with high Opg/Rankl ratios. Using RNA sequencing and chromatin immunoprecipitation-Seq analyses, we demonstrate that DLX3 regulates transcription factors crucial for bone formation such as Dlx5, Dlx6, Runx2 and Sp7 as well as genes important to mineral deposition (Ibsp, Enpp1, Mepe) and bone turnover (Opg). Furthermore, with the removal of DLX3, we observe increased occupancy of DLX5, as well as increased and earlier occupancy of RUNX2 on the bone-specific osteocalcin promoter. Together, these findings provide novel insight into mechanisms by which DLX3 attenuates bone mass accrual to support bone homeostasis by osteogenic gene pathway regulation.
Collapse
Affiliation(s)
- J Isaac
- Laboratory of Skin Biology, NIAMS, NIH, Bethesda, MD, USA
| | - J Erthal
- Laboratory of Skin Biology, NIAMS, NIH, Bethesda, MD, USA
| | - J Gordon
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - O Duverger
- Laboratory of Skin Biology, NIAMS, NIH, Bethesda, MD, USA
| | - H-W Sun
- Biodata Mining and Discovery Section, NIAMS, NIH, Bethesda, MD, USA
| | - A C Lichtler
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - G S Stein
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - J B Lian
- Department of Biochemistry, University of Vermont, Burlington, VT, USA
| | - M I Morasso
- Laboratory of Skin Biology, NIAMS, NIH, Bethesda, MD, USA
| |
Collapse
|
34
|
Yagi M, Arentsen L, Shanley RM, Rosen CJ, Kidder LS, Sharkey LC, Yee D, Koizumi M, Ogawa K, Hui SK. A dual-radioisotope hybrid whole-body micro-positron emission tomography/computed tomography system reveals functional heterogeneity and early local and systemic changes following targeted radiation to the murine caudal skeleton. Calcif Tissue Int 2014; 94:544-52. [PMID: 24562595 PMCID: PMC3987955 DOI: 10.1007/s00223-014-9839-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/17/2014] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to develop a longitudinal non-invasive functional imaging method using a dual-radioisotope hybrid micro-positron emission tomography/computed tomography (PET/CT) scanner in order to assess both the skeletal metabolic heterogeneity and the effect of localized radiation that models therapeutic cancer treatment on marrow and bone metabolism. Skeletally mature BALB/c female mice were given clinically relevant local radiation (16 Gy) to the hind limbs on day 0. Micro-PET/CT acquisition was performed serially for the same mice on days -5 and +2 with FDG and days -4 and +3 with NaF. Serum levels of pro-inflammatory cytokines were measured. Significant differences (p < 0.0001) in marrow metabolism (measured by FDG) and bone metabolism (measured by NaF) were observed among bones before radiation, which demonstrates functional heterogeneity in the marrow and mineralized bone throughout the skeleton. Radiation significantly (p < 0.0001) decreased FDG uptake but increased NaF uptake (p = 0.0314) in both irradiated and non-irradiated bones at early time points. An increase in IL-6 was observed with a significant abscopal (distant) effect on marrow and bone metabolic function. Radiation significantly decreased circulating IGF-1 (p < 0.01). Non-invasive longitudinal imaging with dual-radioisotope micro-PET/CT is feasible to investigate simultaneous changes in marrow and bone metabolic function at local and distant skeletal sites in response to focused radiation injury. Distinct local and remote changes may be affected by several cytokines activated early after local radiation exposure. This approach has the potential for longer-term studies to clarify the effects of radiation on marrow and bone.
Collapse
Affiliation(s)
- Masashi Yagi
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Ma Y, Li X, Fu J, Li Y, Gao L, Yang L, Zhang P, Shen J, Wang H. Acetylcholine affects osteocytic MLO-Y4 cells via acetylcholine receptors. Mol Cell Endocrinol 2014; 384:155-64. [PMID: 24508663 DOI: 10.1016/j.mce.2014.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/21/2014] [Accepted: 01/28/2014] [Indexed: 02/06/2023]
Abstract
The identification of the neuronal control of bone remodeling has become one of the many significant recent advances in bone biology. Cholinergic activity has recently been shown to favor bone mass accrual by complex cellular regulatory networks. Here, we identified the gene expression of the muscarinic and nicotinic acetylcholine receptors (m- and nAChRs) in mice tibia tissue and in osteocytic MLO-Y4 cells. Acetylcholine, which is a classical neurotransmitter and an osteo-neuromediator, not only influences the mRNA expression of the AChR subunits but also significantly induces the proliferation and viability of osteocytes. Moreover, acetylcholine treatment caused the reciprocal regulation of RANKL and OPG mRNA expression, which resulted in a significant increase in the mRNA ratio of RANKL:OPG in osteocytes via acetylcholine receptors. The expression of neuropeptide Y and reelin, which are two neurogenic markers, was also modulated by acetylcholine via m- and nAChRs in MLO-Y4 cells. These results indicated that osteocytic acetylcholine receptors might be a new valuable mediator for cell functions and even for bone remodeling.
Collapse
Affiliation(s)
- Yuanyuan Ma
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xianxian Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jing Fu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yue Li
- Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing 400016, China; The Affiliated Hospital of Stomatology, Chongqing Medical University, Chongqing 400016, China
| | - Li Gao
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Ling Yang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Ping Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jiefei Shen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Hang Wang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
36
|
Guo S, Guo W, Ding Y, Gong J, Zou Q, Xie D, Chen Y, Wu Y, Tian W. Comparative Study of Human Dental Follicle Cell Sheets and Periodontal Ligament Cell Sheets for Periodontal Tissue Regeneration. Cell Transplant 2013; 22:1061-73. [PMID: 23007138 DOI: 10.3727/096368912x656036] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Periodontal ligament cell (PDLC) sheets have been shown to contribute to periodontal tissue regeneration. Dental follicle cells (DFCs), acknowledged as the precursor cells of PDLCs, have demonstrated stemness, embryonic features, heterogeneity, and pluripotency. Therefore, we hypothesized that DFC sheets might be more effective and suitable for periodontal tissue regeneration than PDLC sheets. In this study, we compared the biological characteristics of DFC sheets and PDLC sheets in vitro. To investigate the potential for periodontal tissue regeneration in vivo, complexes composed of two types of cell sheets combined with dentin matrix were implanted subcutaneously into nude mice for 6 weeks. Our results showed that, when forming cell sheets, DFCs secreted richer extracellular matrix than PDLCs. And compared to DFCs, DFC sheets expressed high levels of calcification-related genes, including alkaline phosphatase ( alp), bone sialoprotein ( bsp), osteopontin ( opn), runt-related transcription factor ( runx2), as well as the periodontal ligament-specific genes collagen III ( col III) and periostin, while the gene expression of bsp, osteocalcin ( ocn), and opn were greatly increased in PDLC sheets, when compared to PDLCs. col I expression did not change significantly. However, cementum protein 23 ( cp-23) expression increased several fold in PDLC sheets compared to PDLCs but decreased in DFC sheets compared to DFCs. DFC and PDLC sheets were both positive for Collagen I (Col I), cementum attachment protein (CAP), ALP, BSP, OCN, and OPN protein expression, and Col I, ALP, BSP, and OPN expression were increased after cell sheets were formed. Furthermore, the levels of laminin and fibronectin were higher in DFCs and DFC sheets than that of PDLCs and PDLC sheets, respectively. In vivo, DFC and PDLC sheets could both regenerate periodontal tissue-like structures, but DFC sheets demonstrated stronger periodontal regeneration potential than PDLC sheets. Therefore, DFC sheets derived from discarded dental follicle tissue after tooth extraction may be more advantageous for clinical periodontal tissue regeneration in the future.
Collapse
Affiliation(s)
- Shujuan Guo
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Periodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Weihua Guo
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
| | - Yi Ding
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Periodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Jian Gong
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Periodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Qing Zou
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
| | - Dan Xie
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
| | - Yali Chen
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Periodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Yafei Wu
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Periodontology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Weidong Tian
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China
- Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| |
Collapse
|
37
|
Alghamdi HS, Jansen JA. Bone Regeneration Associated with Nontherapeutic and Therapeutic Surface Coatings for Dental Implants in Osteoporosis. TISSUE ENGINEERING PART B-REVIEWS 2013; 19:233-53. [DOI: 10.1089/ten.teb.2012.0400] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Hamdan S. Alghamdi
- Department of Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
- Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - John A. Jansen
- Department of Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
38
|
Kingsmill VJ, McKay IJ, Ryan P, Ogden MR, Rawlinson SC. Gene expression profiles of mandible reveal features of both calvarial and ulnar bones in the adult rat. J Dent 2013. [DOI: 10.1016/j.jdent.2012.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
39
|
Flynn JM, Spusta SC, Rosen CJ, Melov S. Single cell gene expression profiling of cortical osteoblast lineage cells. Bone 2013; 53:174-81. [PMID: 23238121 PMCID: PMC3589579 DOI: 10.1016/j.bone.2012.11.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/20/2012] [Accepted: 11/30/2012] [Indexed: 10/27/2022]
Abstract
In tissues with complex architectures such as bone, it is often difficult to purify and characterize specific cell types via molecular profiling. Single cell gene expression profiling is an emerging technology useful for characterizing transcriptional profiles of individual cells isolated from heterogeneous populations. In this study we describe a novel procedure for the isolation and characterization of gene expression profiles of single osteoblast lineage cells derived from cortical bone. Mixed populations of different cell types were isolated from adult long bones of C57BL/6J mice by enzymatic digestion, and subsequently subjected to FACS to purify and characterize osteoblast lineage cells via a selection strategy using antibodies against CD31, CD45, and alkaline phosphatase (AP), specific for mature osteoblasts. The purified individual osteoblast lineage cells were then profiled at the single cell level via nanofluidic PCR. This method permits robust gene expression profiling on single osteoblast lineage cells derived from mature bone, potentially from anatomically distinct sites. In conjunction with this technique, we have also shown that it is possible to carry out single cell profiling on cells purified from fixed and frozen bone samples without compromising the gene expression signal. The latter finding means the technique can be extended to biopsies of bone from diseased individuals. Our approach for single cell expression profiling provides a new dimension to the transcriptional profile of the primary osteoblast lineage population in vivo, and has the capacity to greatly expand our understanding of how these cells may function in vivo under normal and diseased states.
Collapse
Affiliation(s)
- James M. Flynn
- Buck Institute for Research on Aging. 8001 Redwood Blvd. Novato, CA 94945
| | - Steven C. Spusta
- Buck Institute for Research on Aging. 8001 Redwood Blvd. Novato, CA 94945
| | - Clifford J. Rosen
- Center for Clinical and Translational Research, Maine Medical Center Research Institute. 81 Research Dr. Scarborough, ME 04074
| | - Simon Melov
- Buck Institute for Research on Aging. 8001 Redwood Blvd. Novato, CA 94945
| |
Collapse
|
40
|
Patil AS, Merchant Y, Nagarajan P. Tissue Engineering of Craniofacial Tissues – A Review. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2050-1218-2-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
41
|
Das-Gupta V, Williamson RA, Pitsillides AA. Expression of endothelial nitric oxide synthase protein is not necessary for mechanical strain-induced nitric oxide production by cultured osteoblasts. Osteoporos Int 2012; 23:2635-47. [PMID: 22402674 DOI: 10.1007/s00198-012-1957-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 12/13/2011] [Indexed: 02/07/2023]
Abstract
UNLABELLED Regulation of nitric oxide (NO) production is considered essential in mechanical load-related osteogenesis. We examined whether osteoblast endothelial NO synthase (eNOS)-derived NO production was regulated by HSP90. We found that HSP90 is essential for strain-related NO release but appears to be independent of eNOS in cultured osteoblasts. INTRODUCTION NO is a key regulator of bone mass, and its production by bone cells is regarded as essential in mechanical strain-related osteogenesis. We sought to identify whether bone cell NO production relied upon eNOS, considered to be the predominant NOS isoform in bone, and whether this was regulated by an HSP90-dependent mechanism. METHODS Using primary rat long bone-derived osteoblasts, the ROS 17/2.8 cell line and primary mouse osteoblasts, derived from wild-type and eNOS-deficient (eNOS(-/-)) mice, we examined by immunoblotting the expression of eNOS using a range of well-characterised antibodies and extraction methods, measured NOS activity by monitoring the conversion of radiolabelled L-arginine to citrulline and examined the production of NO by bone cells subjected to mechanical strain application under various conditions. RESULTS Our studies have revealed that eNOS protein and activity were both undetectable in osteoblast-like cells, that mechanical strain-induced NO production was retained in bone cells from eNOS-deficient mice, but that this strain-related induction of NO production was, however, dependent upon HSP90. CONCLUSIONS Together, our studies indicate that HSP90 activity is essential for strain-related NO release by cultured osteoblasts and that this is highly likely to be achieved by an eNOS-independent mechanism.
Collapse
Affiliation(s)
- V Das-Gupta
- Department of Veterinary Basic Science, Royal Veterinary College, London, NW1 0TU, UK
| | | | | |
Collapse
|
42
|
Proksch S, Steinberg T, Stampf S, Schwarz U, Hellwig E, Tomakidi P. Crosstalk on cell behavior in interactive cocultures of hMSCs with various oral cell types. Tissue Eng Part A 2012; 18:2601-10. [PMID: 22881458 DOI: 10.1089/ten.tea.2012.0041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
When prospectively applied for regenerative therapies, human bone-marrow-derived mesenchymal stem cells (hMSCs) interact with the locally residing host cells. With respect to the developmentally particular origin of oral cells, little is known about the putatively discriminative behavioral responses of hMSCs in interaction with various oral cell types, including human alveolar bone osteoblasts (hOAs), periodontal ligament fibroblasts (hPDLs), and gingival fibroblasts (hGFs). To assess the crosstalk between hMSCs and oral cells, interactive cocultures were established by combining well-characterized hMSCs with hOAs, hPDLs, or hGFs, and the behavioral hMSC aspects, that is, proliferation and gene expression, were measured by employing a 5-bromo-2'-deoxyuridine assay and real-time polymerase chain reaction, while apoptosis was quantified by in situ cell death detection kit. hMSCs expressed the typical antigen spectrum lacking CD34, CD45, CD14, CD19, and HLA-DR, while expressing CD73, CD90, and CD105, and could successfully be transformed into adipocytes, osteocytes, and chondrocytes. Monocultured control hMSCs proliferated readily, whereas a general reduction of BrdU-labeled cells was observed in cocultures. Globally, upon extending time periods, interactive coculture combinations of hMSCs with hOAs reduced both osteogenic gene and stem cell marker transcription in hMSCs, a phenomenon appearing less pronounced by combining hMSCs with hPDLs, such that the observed effects in terms of proliferation and gene expression followed the same ranking: hOAs>hGFs>hPDLs. Vice versa, in interactive hMSC cocultures, the cell survival rate was significantly increased, irrespective from the combined coculture cell counterpart. Our results show for the first time that behavior of hMSCs reflected by proliferation and gene expression was governed by interaction with various oral cells in a cell-type-discriminative manner. In addition, hMSC coculture restrains apoptosis, such that influences on cell behavior appear as a crosstalk. In summary, interactive cocultures render the basis for a prospective prediction of mutual cell behavior in hMSC-based oral tissue regeneration disclosing that oral cells shift hMSC behavior from proliferation to differentiation and apoptosis-repressing features.
Collapse
Affiliation(s)
- Susanne Proksch
- Department of Operative Dentistry and Periodontology, Dental School and Hospital, University Freiburg Medical Centre, Freiburg, Germany
| | | | | | | | | | | |
Collapse
|
43
|
Medina-Gomez C, Kemp JP, Estrada K, Eriksson J, Liu J, Reppe S, Evans DM, Heppe DHM, Vandenput L, Herrera L, Ring SM, Kruithof CJ, Timpson NJ, Zillikens MC, Olstad OK, Zheng HF, Richards JB, St. Pourcain B, Hofman A, Jaddoe VWV, Smith GD, Lorentzon M, Gautvik KM, Uitterlinden AG, Brommage R, Ohlsson C, Tobias JH, Rivadeneira F. Meta-analysis of genome-wide scans for total body BMD in children and adults reveals allelic heterogeneity and age-specific effects at the WNT16 locus. PLoS Genet 2012; 8:e1002718. [PMID: 22792070 PMCID: PMC3390371 DOI: 10.1371/journal.pgen.1002718] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 04/04/2012] [Indexed: 12/31/2022] Open
Abstract
To identify genetic loci influencing bone accrual, we performed a genome-wide association scan for total-body bone mineral density (TB-BMD) variation in 2,660 children of different ethnicities. We discovered variants in 7q31.31 associated with BMD measurements, with the lowest P = 4.1×10−11 observed for rs917727 with minor allele frequency of 0.37. We sought replication for all SNPs located ±500 kb from rs917727 in 11,052 additional individuals from five independent studies including children and adults, together with de novo genotyping of rs3801387 (in perfect linkage disequilibrium (LD) with rs917727) in 1,014 mothers of children from the discovery cohort. The top signal mapping in the surroundings of WNT16 was replicated across studies with a meta-analysis P = 2.6×10−31 and an effect size explaining between 0.6%–1.8% of TB-BMD variance. Conditional analyses on this signal revealed a secondary signal for total body BMD (P = 1.42×10−10) for rs4609139 and mapping to C7orf58. We also examined the genomic region for association with skull BMD to test if the associations were independent of skeletal loading. We identified two signals influencing skull BMD variation, including rs917727 (P = 1.9×10−16) and rs7801723 (P = 8.9×10−28), also mapping to C7orf58 (r2 = 0.50 with rs4609139). Wnt16 knockout (KO) mice with reduced total body BMD and gene expression profiles in human bone biopsies support a role of C7orf58 and WNT16 on the BMD phenotypes observed at the human population level. In summary, we detected two independent signals influencing total body and skull BMD variation in children and adults, thus demonstrating the presence of allelic heterogeneity at the WNT16 locus. One of the skull BMD signals mapping to C7orf58 is mostly driven by children, suggesting temporal determination on peak bone mass acquisition. Our life-course approach postulates that these genetic effects influencing peak bone mass accrual may impact the risk of osteoporosis later in life. Genetic investigations on bone mineral density (BMD) variation in children allow the identification of factors determining peak bone mass and their influence on developing osteoporosis later in life. We ran a genome-wide association study (GWAS) for total body BMD based on 2,660 children of different ethnic backgrounds, followed by replication in an additional 12,066 individuals comprising children, young adults, and elderly populations. Our GWAS meta-analysis identified two independent signals in the 7q31.31 locus, arising from SNPs in the vicinity of WNT16, FAM3C, and C7orf58. These variants were also associated with skull BMD, a skeletal trait with much less environmental influence for which one of the signals displayed age-specific effects. Integration of functional studies in a Wnt16 knockout mouse model and gene expression profiles in human bone tissue provided additional evidence that WNT16 and C7orf58 underlie the described associations. All together our findings demonstrate the relevance of these factors for bone biology, the attainment of peak bone mass, and their likely impact on bone fragility later in life.
Collapse
Affiliation(s)
- Carolina Medina-Gomez
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - John P. Kemp
- MRC CAiTE Centre, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
- Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Karol Estrada
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - Joel Eriksson
- Center for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jeff Liu
- Lexicon Pharmaceuticals, The Woodlands, Texas, United States of America
| | - Sjur Reppe
- Department of Medical Biochemistry, Oslo University Hospital, Ullevaal, Oslo, Norway
| | - David M. Evans
- MRC CAiTE Centre, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
- Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Denise H. M. Heppe
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Liesbeth Vandenput
- Center for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lizbeth Herrera
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Susan M. Ring
- Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Claudia J. Kruithof
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nicholas J. Timpson
- MRC CAiTE Centre, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
- Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - M. Carola Zillikens
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - Ole K. Olstad
- Department of Medical Biochemistry, Oslo University Hospital, Ullevaal, Oslo, Norway
| | - Hou-Feng Zheng
- Department of Medicine, Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Epidemiology and Biostatistics, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - J. Brent Richards
- Department of Medicine, Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Epidemiology and Biostatistics, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
- Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Beate St. Pourcain
- MRC CAiTE Centre, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Albert Hofman
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - Vincent W. V. Jaddoe
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - George Davey Smith
- MRC CAiTE Centre, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
- Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Mattias Lorentzon
- Center for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kaare M. Gautvik
- Department of Medical Biochemistry, Oslo University Hospital, Ullevaal, Oslo, Norway
- Department of Medical Biochemistry, Oslo Deacon Hospital, Oslo, Norway
| | - André G. Uitterlinden
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - Robert Brommage
- Lexicon Pharmaceuticals, The Woodlands, Texas, United States of America
| | - Claes Ohlsson
- Center for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jonathan H. Tobias
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Fernando Rivadeneira
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
- The Generation R Study Group, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Netherlands Genomics Initiative (NGI)–sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
- * E-mail:
| |
Collapse
|
44
|
Ma Y, Wu X, Li X, Fu J, Shen J, Li X, Wang H. Corticosterone regulates the expression of neuropeptide Y and reelin in MLO-Y4 cells. Mol Cells 2012; 33:611-6. [PMID: 22610366 PMCID: PMC3887760 DOI: 10.1007/s10059-012-0053-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/18/2012] [Accepted: 04/19/2012] [Indexed: 12/13/2022] Open
Abstract
Osteocytes that have a dendritic appearance are widely believed to form a complex cellular network system and play crucial roles in mechanotransduction as a principal bone mechanosensor, which is the basis of their neuronallike biology, as previously reported. Neuropeptide Y (NPY) and reelin mRNA, which are brain-specific neurogenic markers, have been identified in osteocytes. However, changes in the production of NPY and reelin in response to specific biochemical stimulation are unknown. In this study, we investigated the in vitro effect of corticosterone, one of the endogenous glucocorticoids, on the expression of NPY and reelin in the MLO-Y4 osteocyte cell line. Cells were treated with corticosterone at different concentrations (10(-9) M-10(-5) M) for 1, 3, 6, 12 and 24 h. As revealed, corticosterone reduced the MLO-Y4 cell viability and proliferation in a dose- and time-dependent manner based on an MTT assay and a Vi-CELL analyzer. The cells were then incubated with corticosterone (10(-6) μM), and the NPY and reelin expression levels were detected at 1, 3, 6, 12 and 24 h using real-time PCR and Western blot analysis. These results demonstrated that at the gene and the protein levels, corticosterone significantly upregulated the NPY and reelin expression in a time-dependent manner. The application of a glucocorticoid receptor antagonist, RU486, reversed the reduced cell viability and the increased expression of NPY and reelin that were caused by corticosterone. To the best of our knowledge, this is the first report to verify that corticosterone regulates the NPY and reelin expression in osteocytes.
Collapse
Affiliation(s)
- Yuanyuan Ma
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| | - Xiangnan Wu
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| | - Xianxian Li
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| | - Jing Fu
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| | - Jiefei Shen
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| | - Xiaoyu Li
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
| | - Hang Wang
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041,
China
- Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041,
China
| |
Collapse
|
45
|
Javaheri B, Sunters A, Zaman G, Suswillo RFL, Saxon LK, Lanyon LE, Price JS. Lrp5 is not required for the proliferative response of osteoblasts to strain but regulates proliferation and apoptosis in a cell autonomous manner. PLoS One 2012; 7:e35726. [PMID: 22567110 PMCID: PMC3342322 DOI: 10.1371/journal.pone.0035726] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/22/2012] [Indexed: 11/19/2022] Open
Abstract
Although Lrp5 is known to be an important contributor to the mechanisms regulating bone mass, its precise role remains unclear. The aim of this study was to establish whether mutations in Lrp5 are associated with differences in the growth and/or apoptosis of osteoblast-like cells and their proliferative response to mechanical strain in vitro. Primary osteoblast-like cells were derived from cortical bone of adult mice lacking functional Lrp5 (Lrp5(-/-)), those heterozygous for the human G171V High Bone Mass (HBM) mutation (LRP5(G171V)) and their WT littermates (WT(Lrp5), WT(HBM)). Osteoblast proliferation over time was significantly higher in cultures of cells from LRP5(G171V) mice compared to their WT(HBM) littermates, and lower in Lrp5(-/-) cells. Cells from female LRP5(G171V) mice grew more rapidly than those from males, whereas cells from female Lrp5(-/-) mice grew more slowly than those from males. Apoptosis induced by serum withdrawal was significantly higher in cultures from Lrp5(-/-) mice than in those from WT(HBM) or LRP5(G171V) mice. Exposure to a single short period of dynamic mechanical strain was associated with a significant increase in cell number but this response was unaffected by genotype which also did not change the 'threshold' at which cells responded to strain. In conclusion, the data presented here suggest that Lrp5 loss and gain of function mutations result in cell-autonomous alterations in osteoblast proliferation and apoptosis but do not alter the proliferative response of osteoblasts to mechanical strain in vitro.
Collapse
Affiliation(s)
- Behzad Javaheri
- Department of Oral Biology, UMKC School of Dentistry, Kansas City, Missouri, United States of America.
| | | | | | | | | | | | | |
Collapse
|
46
|
Prado RFD, Silveira VÁS, Rocha RFD, Vasconcellos LMRD, Carvalho YR. Effects of experimental osteoporosis and low calcium intake on postextraction sockets of rats. Int J Exp Pathol 2012; 93:139-47. [PMID: 22364763 PMCID: PMC3385706 DOI: 10.1111/j.1365-2613.2012.00809.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 12/25/2011] [Indexed: 12/18/2022] Open
Abstract
This study analysed the initial effects of the combination of oestrogen deficiency with a calcium-deficient diet on alveolar bone repair. Sixty-three 3-month-old female rats were either ovariectomized (OVX, n = 42) or sham-operated (SHAM, n = 21). Among the 42 ovariectomized rats, 21 received standard commercial food (OVX) and 21 received food with low calcium content (ESP). The mandibular first molars were extracted bilaterally 15 days after ovariectomy or sham surgery. The rats were weighed and killed at 7, 21 and 45 days after tooth extraction. The results were evaluated by descriptive microscopic analysis, histomorphometry of the trabecular and osteoid volume and mast cell counts. Analysis of the results indicated that trabecular volume and mast cell counts increased significantly over time, while osteoid volume decreased over time. Comparisons between the SHAM and OVX groups demonstrated no statistical differences, while comparison between the OVX and ESP groups indicated differences in trabecular volume and the number of mast cells. The data suggest that hormonal deficiency does not delay alveolar bone repair in OVX rats; however, oestrogen deficiency associated with calcium deficiency can lead to bone resorption through the activation of mast cells.
Collapse
Affiliation(s)
- Renata F D Prado
- Department of Physiotherapy, Cruzeiro Superior School - ESC, Cruzeiro, São Paulo, Brazil.
| | | | | | | | | |
Collapse
|
47
|
Pitsillides AA, Rawlinson SCF. Using cell and organ culture models to analyze responses of bone cells to mechanical stimulation. Methods Mol Biol 2012; 816:593-619. [PMID: 22130954 DOI: 10.1007/978-1-61779-415-5_37] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Bone cells of the osteoblastic lineage are responsive to the local mechanical environment. Through integration of a number of possible loading-induced regulatory stimuli, osteocyte, osteoblast, and osteoclast behaviour is organized to fashion a skeletal element of sufficient strength and toughness to resist fracture and crack propagation. Early pre-osteogenic responses had been determined in vivo and this led to the development of bone organ culture models to elucidate other pre-osteogenic responses where osteocytes and osteoblasts retain the natural orientation, connections and attachments to their native extracellular matrix. The application of physiological mechanical loads to bone in these organ culture models generates the regulatory stimuli. As a consequence, these experiments can be used to illustrate the distinctive mechanisms by which osteocytes and osteoblasts respond to mechanical loads and also differences in these responses, suggesting co-ordinated and cooperatively between cell populations. Organ explant cultures are awkward to maintain, and have a limited life, but length of culture times are improving. Monolayer cultures are much easier to maintain and permit the application of a particular mechanical stimulation to be studied in isolation; mainly direct mechanical strain or fluid shear strains. These allow for the response of a single cell type to the applied mechanical stimulation to be monitored precisely.The techniques that can be used to apply mechanical strain to bone and bone cells have not advanced greatly since the first edition. The output from such experiments has, however, increased substantially and their importance is now more broadly accepted. This suggests a growing use of these approaches and an increasing awareness of the importance of the mechanical environment in controlling normal bone cell behaviour. We expand the text to include additions and modifications made to the straining apparatus and update the research cited to support this growing role of cell and organ culture models to analyze responses of bone cells to mechanical stimulation.
Collapse
Affiliation(s)
- Andrew A Pitsillides
- Department of Veterinary Basic Sciences, The Royal Veterinary College, Royal College Street, London, UK.
| | | |
Collapse
|
48
|
Blake GM, Siddique M, Frost ML, Moore AEB, Fogelman I. Radionuclide studies of bone metabolism: do bone uptake and bone plasma clearance provide equivalent measurements of bone turnover? Bone 2011; 49:537-42. [PMID: 21689803 DOI: 10.1016/j.bone.2011.05.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 05/27/2011] [Accepted: 05/31/2011] [Indexed: 11/15/2022]
Abstract
Quantitative radionuclide imaging using (18)F-fluoride positron emission tomography (18F-PET) or (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scans provides a novel tool for studying regional and whole skeleton bone turnover that complements the information provided by biochemical markers. Radionuclide bone scans can be quantified by measuring either tracer uptake or, if blood sampling is performed, bone plasma clearance. This study examines whether these two methods provide equivalent information about bone turnover. We examined data from two clinical trials of the bone anabolic agent teriparatide. In Study 1 twenty osteoporotic women had 18F-PET scans of the lumbar spine at baseline and after 6 months treatment with teriparatide. Bone uptake in the lumbar spine was expressed as standardised uptake values (SUV) and blood samples taken to evaluate plasma clearance. In Study 2 ten women had (99m)Tc-MDP scans at baseline, 3 and 18 months after starting teriparatide. Blood samples were taken and whole skeleton plasma clearance and bone uptake calculated. In Study 1 spine plasma clearance increased by 23.8% after 6-months treatment (P=0.0003), whilst SUV increased by only 3.0% (P=0.84). In Study 2 whole skeleton plasma clearance increased by 37.1% after 18-months treatment (P=0.0002), whilst the 4-hour whole skeleton uptake increased by only 25.5% (P=0.0001). During treatment the 18F- plasma concentration decrease by 20% and (99m)Tc-MDP concentration by 13%, and these latter changes were sufficient to explain the differences between the uptake and plasma clearance results. Measurements of response to treatment using bone uptake and plasma clearance gave different results because the effects of teriparatide on bone resulted in a sufficiently increased demand for radionuclide tracer from the skeleton that the concentration in the circulation decreased. Similar effects may occur with other therapies that have a large enough effect on bone metabolism. In these circumstances changes in bone plasma clearance give a truer impression of response to treatment than those in SUV or uptake.
Collapse
Affiliation(s)
- Glen M Blake
- Division of Imaging Sciences, King's College London, Guy's Campus, London, UK.
| | | | | | | | | |
Collapse
|
49
|
Reumann MK, Strachna O, Lukashova L, Verdelis K, Donnelly E, Boskey AL, Mayer-Kuckuk P. Early growth response gene 1 regulates bone properties in mice. Calcif Tissue Int 2011; 89:1-9. [PMID: 21533960 DOI: 10.1007/s00223-011-9486-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 03/21/2011] [Indexed: 01/16/2023]
Abstract
Transcriptional regulation of the postnatal skeleton is incompletely understood. Here, we determined the consequence of loss of early growth response gene 1 (EGR-1) on bone properties. Analyses were performed on both the microscopic and molecular levels utilizing micro-computed tomography (micro-CT) and Fourier transform infrared imaging (FTIRI), respectively. Mice deficient in EGR-1 (Egr-1 (-/-)) were studied and compared to sex- and age-matched wild-type (wt) control animals. Femoral trabecular bone in male Egr-1 (-/-) mice demonstrated osteopenic characteristics marked by reductions in both bone volume fraction (BV/TV) and bone mineral density (BMD). Morphological analysis revealed fewer trabeculae in these animals. In contrast, female Egr-1 (-/-) animals had thinner trabeculae, but BV/TV and BMD were not significantly reduced. Analysis of femoral cortical bone at the mid-diaphysis did not show significant osteopenic characteristics but detected changes in cross-sectional geometry in both male and female Egr-1 (-/-) animals. Functionally, this resulted in decreased resistance to three-point bending as indicated by a reduction in maximum load, failure load, and stiffness. Assessment of compositional bone properties, including mineral-to-matrix ratio, carbonate-to-phosphate ratio, crystallinity, and cross-linking, in femurs by FTIRI did not show any significant differences or an appreciable trend between Egr-1 (-/-) and wt mice of either sex. Unexpectedly, rib bone from Egr-1 (-/-) animals displayed distinct osteopenic traits that were particularly pronounced in female mice. This study provides genetic evidence that both sex and skeletal site are critical determinants of EGR-1 activity in vivo and that its site-specific action may contribute to the mechanical properties of bone.
Collapse
Affiliation(s)
- Marie K Reumann
- Bone Cell Biology and Imaging Laboratory, Caspary Research Building, Rm. 623, Hospital for Special Surgery, New York, NY 10021, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Blake GM, Frost ML, Moore AEB, Siddique M, Fogelman I. The assessment of regional skeletal metabolism: studies of osteoporosis treatments using quantitative radionuclide imaging. J Clin Densitom 2011; 14:263-71. [PMID: 21600822 DOI: 10.1016/j.jocd.2011.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/06/2011] [Accepted: 04/04/2011] [Indexed: 11/17/2022]
Abstract
Studies of bone remodeling using bone biopsy and biochemical markers of bone turnover play an important role in research studies to investigate the effect of new osteoporosis treatments on bone quality. Quantitative radionuclide imaging using either positron emission tomography with fluorine-18 sodium fluoride or gamma camera studies with technetium-99m methylene diphosphonate provides a novel tool for studying bone metabolism that complements conventional methods, such as bone turnover markers (BTMs). Unlike BTMs, which measure the integrated response to treatment across the whole skeleton, radionuclide imaging can distinguish the changes occurring at sites of particular clinical interest, such as the spine or proximal femur. Radionuclide imaging can be used to measure either bone uptake or (if done in conjunction with blood sampling) bone plasma clearance. Although the latter is more complicated to perform, unlike bone uptake, it provides a measurement that is specific to the bone metabolic activity at the measurement site. Treatment with risedronate was found to cause a decrease in bone plasma clearance, whereas treatment with the bone anabolic agent teriparatide caused an increase. Studies of teriparatide are of particular interest because the treatment has different effects at different sites in the skeleton, with a substantially greater response in the flat bone of the skull and cortical bone in the femur compared with the lumbar spine. Future studies should include investigations of osteonecrosis of the jaw and atypical fractures of the femur to examine the associated regional changes in bone metabolism and to throw light on the underlying pathologies.
Collapse
Affiliation(s)
- Glen M Blake
- Division of Imaging Sciences, King's College London, Guy's Campus, London, UK.
| | | | | | | | | |
Collapse
|