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Collins JM, Lang A, Parisi C, Moharrer Y, Nijsure MP, Thomas Kim JH, Ahmed S, Szeto GL, Qin L, Gottardi R, Dyment NA, Nowlan NC, Boerckel JD. YAP and TAZ couple osteoblast precursor mobilization to angiogenesis and mechanoregulation in murine bone development. Dev Cell 2024; 59:211-227.e5. [PMID: 38141609 PMCID: PMC10843704 DOI: 10.1016/j.devcel.2023.11.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/07/2023] [Accepted: 11/30/2023] [Indexed: 12/25/2023]
Abstract
Fetal bone development occurs through the conversion of avascular cartilage to vascularized bone at the growth plate. This requires coordinated mobilization of osteoblast precursors with blood vessels. In adult bone, vessel-adjacent osteoblast precursors are maintained by mechanical stimuli; however, the mechanisms by which these cells mobilize and respond to mechanical cues during embryonic development are unknown. Here, we show that the mechanoresponsive transcriptional regulators Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) spatially couple osteoblast precursor mobilization to angiogenesis, regulate vascular morphogenesis to control cartilage remodeling, and mediate mechanoregulation of embryonic murine osteogenesis. Mechanistically, YAP and TAZ regulate a subset of osteoblast-lineage cells, identified by single-cell RNA sequencing as vessel-associated osteoblast precursors, which regulate transcriptional programs that direct blood vessel invasion through collagen-integrin interactions and Cxcl12. Functionally, in 3D human cell co-culture, CXCL12 treatment rescues angiogenesis impaired by stromal cell YAP/TAZ depletion. Together, these data establish functions of the vessel-associated osteoblast precursors in bone development.
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Affiliation(s)
- Joseph M Collins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Annemarie Lang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cristian Parisi
- Department of Bioengineering, Imperial College London, London, UK
| | - Yasaman Moharrer
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Mechanical Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Madhura P Nijsure
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jong Hyun Thomas Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Saima Ahmed
- Department of Bioengineering, Imperial College London, London, UK
| | | | - Ling Qin
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Riccardo Gottardi
- Department of Pediatrics, Division of Pulmonary Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nathaniel A Dyment
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Niamh C Nowlan
- Department of Bioengineering, Imperial College London, London, UK; School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Joel D Boerckel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Collins JM, Lang A, Parisi C, Moharrer Y, Nijsure MP, Kim JH(T, Szeto GL, Qin L, Gottardi RL, Dyment NA, Nowlan NC, Boerckel JD. YAP and TAZ couple osteoblast precursor mobilization to angiogenesis and mechanoregulated bone development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.20.524918. [PMID: 36711590 PMCID: PMC9882292 DOI: 10.1101/2023.01.20.524918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Endochondral ossification requires coordinated mobilization of osteoblast precursors with blood vessels. During adult bone homeostasis, vessel adjacent osteoblast precursors respond to and are maintained by mechanical stimuli; however, the mechanisms by which these cells mobilize and respond to mechanical cues during embryonic development are unknown. Previously, we found that deletion of the mechanoresponsive transcriptional regulators, YAP and TAZ, from Osterix-expressing osteoblast precursors and their progeny caused perinatal lethality. Here, we show that embryonic YAP/TAZ signaling couples vessel-associated osteoblast precursor mobilization to angiogenesis in developing long bones. Osterix-conditional YAP/TAZ deletion impaired endochondral ossification in the primary ossification center but not intramembranous osteogenesis in the bone collar. Single-cell RNA sequencing revealed YAP/TAZ regulation of the angiogenic chemokine, Cxcl12, which was expressed uniquely in vessel-associated osteoblast precursors. YAP/TAZ signaling spatially coupled osteoblast precursors to blood vessels and regulated vascular morphogenesis and vessel barrier function. Further, YAP/TAZ signaling regulated vascular loop morphogenesis at the chondro-osseous junction to control hypertrophic growth plate remodeling. In human cells, mesenchymal stromal cell co-culture promoted 3D vascular network formation, which was impaired by stromal cell YAP/TAZ depletion, but rescued by recombinant CXCL12 treatment. Lastly, YAP and TAZ mediated mechanotransduction for load-induced osteogenesis in embryonic bone.
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Affiliation(s)
- Joseph M. Collins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Annemarie Lang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cristian Parisi
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Yasaman Moharrer
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Mechanical Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Madhura P. Nijsure
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jong Hyun (Thomas) Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Ling Qin
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Riccardo L. Gottardi
- Department of Pediatrics, Division of Pulmonary Medicine, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nathanial A. Dyment
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Niamh C. Nowlan
- Department of Bioengineering, Imperial College London, London, United Kingdom
- School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland
- UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Joel D. Boerckel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Shen N, Maggio M, Woods I, C. Lowry M, Almasri R, Gorgun C, Eichholz K, Stavenschi E, Hokamp K, Roche F, O’Driscoll L, Hoey D. Mechanically activated mesenchymal-derived bone cells drive vessel formation via an extracellular vesicle mediated mechanism. J Tissue Eng 2023; 14:20417314231186918. [PMID: 37654438 PMCID: PMC10467237 DOI: 10.1177/20417314231186918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/23/2023] [Indexed: 09/02/2023] Open
Abstract
Blood vessel formation is an important initial step for bone formation during development as well as during remodelling and repair in the adult skeleton. This results in a heavily vascularized tissue where endothelial cells and skeletal cells are constantly in crosstalk to facilitate homeostasis, a process that is mediated by numerous environmental signals, including mechanical loading. Breakdown in this communication can lead to disease and/or poor fracture repair. Therefore, this study aimed to determine the role of mature bone cells in regulating angiogenesis, how this is influenced by a dynamic mechanical environment, and understand the mechanism by which this could occur. Herein, we demonstrate that both osteoblasts and osteocytes coordinate endothelial cell proliferation, migration, and blood vessel formation via a mechanically dependent paracrine mechanism. Moreover, we identified that this process is mediated via the secretion of extracellular vesicles (EVs), as isolated EVs from mechanically stimulated bone cells elicited the same response as seen with the full secretome, while the EV-depleted secretome did not elicit any effect. Despite mechanically activated bone cell-derived EVs (MA-EVs) driving a similar response to VEGF treatment, MA-EVs contain minimal quantities of this angiogenic factor. Lastly, a miRNA screen identified mechanoresponsive miRNAs packaged within MA-EVs which are linked with angiogenesis. Taken together, this study has highlighted an important mechanism in osteogenic-angiogenic coupling in bone and has identified the mechanically activated bone cell-derived EVs as a therapeutic to promote angiogenesis and potentially bone repair.
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Affiliation(s)
- N. Shen
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - M. Maggio
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - I. Woods
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - M. C. Lowry
- School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, and Trinity St. James’s Cancer Institute, Trinity College Dublin, Dublin, Ireland
| | - R. Almasri
- School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, and Trinity St. James’s Cancer Institute, Trinity College Dublin, Dublin, Ireland
| | - C. Gorgun
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - K.F. Eichholz
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - E. Stavenschi
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
| | - K. Hokamp
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, College Green, Dublin, Ireland
| | - F.M. Roche
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, College Green, Dublin, Ireland
| | - L. O’Driscoll
- School of Pharmacy and Pharmaceutical Sciences, Trinity Biomedical Sciences Institute, and Trinity St. James’s Cancer Institute, Trinity College Dublin, Dublin, Ireland
| | - D.A. Hoey
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
- Department of Mechanical, Manufacturing, and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland
- Advanced Materials and Bioengineering Research Centre, Trinity College Dublin and Royal College of Surgeons in Ireland, Dublin, Ireland
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4
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Functional Heterogeneity of Bone Marrow Mesenchymal Stem Cell Subpopulations in Physiology and Pathology. Int J Mol Sci 2022; 23:ijms231911928. [PMID: 36233230 PMCID: PMC9570000 DOI: 10.3390/ijms231911928] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/16/2022] Open
Abstract
Bone marrow mesenchymal stem cells (BMSCs) are multi-potent cell populations and are capable of maintaining bone and body homeostasis. The stemness and potential therapeutic effect of BMSCs have been explored extensively in recent years. However, diverse cell surface antigens and complex gene expression of BMSCs have indicated that BMSCs represent heterogeneous populations, and the natural characteristics of BMSCs make it difficult to identify the specific subpopulations in pathological processes which are often obscured by bulk analysis of the total BMSCs. Meanwhile, the therapeutic effect of total BMSCs is often less effective partly due to their heterogeneity. Therefore, understanding the functional heterogeneity of the BMSC subpopulations under different physiological and pathological conditions could have major ramifications for global health. Here, we summarize the recent progress of functional heterogeneity of BMSC subpopulations in physiology and pathology. Targeting tissue-resident single BMSC subpopulation offers a potentially innovative therapeutic strategy and improves BMSC effectiveness in clinical application.
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Grewe JM, Knapstein PR, Donat A, Jiang S, Smit DJ, Xie W, Keller J. The role of sphingosine-1-phosphate in bone remodeling and osteoporosis. Bone Res 2022; 10:34. [PMID: 35396384 PMCID: PMC8993882 DOI: 10.1038/s41413-022-00205-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/17/2021] [Accepted: 01/17/2022] [Indexed: 12/27/2022] Open
Abstract
Osteoporosis is a systemic bone disease that affects more than 200 million people worldwide and is caused by the disruption of the equilibrium between osteoclastic bone resorption and osteoblastic bone formation. Sphingosine-1-phosphate (S1P) is a natural, bioactive sphingolipid that has been shown to play a major role in cardiovascular and immunological pathologies by regulating biological and cellular processes, including migration, differentiation, proliferation and survival. Recent studies also suggest a central role for S1P in bone diseases, including osteoporosis; however, the effects of S1P, particularly in bone metabolism, remain to be further elucidated. In this review, we summarize the available literature on the role of S1P in bone metabolism with a focus on osteoporosis. On the cellular level, S1P acts as an osteoclast-osteoblast coupling factor to promote osteoblast proliferation and bone formation. Moreover, the recruitment of osteoclast precursors to resorption sites is regulated by the interplay of S1P gradients and S1P receptor expression. From a clinical perspective, increasing evidence suggests that systemically elevated S1P blood levels may serve as an independent risk factor for osteoporosis-related fractures. Taken together, S1P signaling is a potential therapeutic target and may serve as a novel biomarker in patients with systemic bone disease.
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Affiliation(s)
- Justus M Grewe
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.,Clinic and Polyclinic for Vascular Medicine, University Heart Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Paul-Richard Knapstein
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Antonia Donat
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Shan Jiang
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Daniel J Smit
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Weixin Xie
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Johannes Keller
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
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Man QW, Li RF, Li SR, Wang J, Bu LL, Zhao Y, Liu B. Single-Cell RNA Sequencing Reveals CXCLs Enriched Fibroblasts Within Odontogenic Keratocysts. J Inflamm Res 2022; 14:7359-7369. [PMID: 34992422 PMCID: PMC8713881 DOI: 10.2147/jir.s342951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/10/2021] [Indexed: 12/02/2022] Open
Abstract
Purpose We aimed to define cell subpopulations of odontogenic keratocyst (OKC), particularly relating to angiogenesis and explored the potential regulation mechanism for angiogenesis. Materials and Methods Single-cell RNA sequencing (scRNA-seq) analysis was investigated on 14,072 cells from 3 donors with OKC. The differential expressed genes, cell trajectory and intercellular communications were evaluated by bioinformatic analysis. Hydrostatic pressure (80 mmHg, 6h) was applied to the primary fibroblasts of OKC and the supernatant was collected for cytokines detection by cytokine antibody array. The chemokine (C-X-C motif) ligand 12 (CXCL12) and CD31 expressions were explored by immunohistochemistry in tissue microarray of OKC. Results Five different cell types were identified in the epithelium of OKC and 3 different cell types in the OKC fibroblasts were characterized, indicating high intra-lesional heterogeneity. CXCLs were highly enriched in the subset of fibroblasts and showed close interactions with endothelial cells. Hydrostatic pressure (80mmHg) significantly increased CXCL12 secretions in OKC fibroblasts. Stromal CXCL12 expressions were closely related to CD31 expressions of tissue microarray of OKC. Conclusion CXCLs enriched fibroblasts are crucial for angiogenesis of OKCs which could be partially regulated by hydrostatic pressure.
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Affiliation(s)
- Qi-Wen Man
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.,Department of Oral and Maxillofacial Head Neck Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Rui-Fang Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Su-Ran Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Jing Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Lin-Lin Bu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.,Department of Oral and Maxillofacial Head Neck Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Yi Zhao
- Department of Prosthodontics, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Bing Liu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.,Department of Oral and Maxillofacial Head Neck Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
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Nokhbatolfoghahaei H, Rad MR, Paknejad Z, Ardeshirylajimi A, Khojasteh A. Identification osteogenic signaling pathways following mechanical stimulation: A systematic review. Curr Stem Cell Res Ther 2021; 17:772-792. [PMID: 34615453 DOI: 10.2174/1574888x16666211006105915] [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: 05/09/2021] [Revised: 07/17/2021] [Accepted: 07/26/2021] [Indexed: 11/22/2022]
Abstract
INTRODUCTION It has been shown that mechanical forces can induce or promote osteogenic differentiation as well as remodeling of the new created bone tissues. To apply this characteristic in bone tissue engineering, it is important to know which mechanical stimuli through which signaling pathway has a more significant impact on osteogenesis. METHODS In this systematic study, an electronic search was conducted using PubMed and Google Scholar databases. This study has been prepared and organized according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Included studies were first categorized according to the in vivo and in vitro studies. RESULTS Six types of mechanical stresses were used in these articles and the most commonly used mechanical force and cell source were tension and bone marrow-derived mesenchymal stem cells (BMMSCs), respectively. These forces were able to trigger twelve signaling pathways in which Wnt pathway was so prominent. CONCLUSION 1) Although specific signaling pathways are induced through specific mechanical forces, Wnt signaling pathways are predominantly activated by almost all types of force/stimulation, 2) All signaling pathways regulate expression of RUNX2, which is known as a master regulator of osteogenesis, 3) In Tension force, the mode of force administration, i.e, continuous or non-continuous tension is more important than the percentage of elongation.
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Affiliation(s)
- Hanieh Nokhbatolfoghahaei
- Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran. Iran
| | - Maryam Rezai Rad
- Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran. Iran
| | - Zahrasadat Paknejad
- Medical nanotechnology and tissue engineering research Center, Shahid Beheshti University of Medical Sciences, Tehran. Iran
| | - Abdolreza Ardeshirylajimi
- Department of Tissue Engineering, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran. Iran
| | - Arash Khojasteh
- Department of Tissue Engineering, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran. Iran
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8
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Mumtaz H, Lara-Castillo N, Scott JM, Begonia M, Dallas M, Johnson ML, Ganesh T. Age and gender related differences in load-strain response in C57Bl/6 mice. Aging (Albany NY) 2020; 12:24721-24733. [PMID: 33346747 PMCID: PMC7803533 DOI: 10.18632/aging.202350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 09/09/2020] [Indexed: 06/12/2023]
Abstract
We examined the changes in mechanical strain response of male and female mouse tibia and ulna, using axial compression tests, to assess age-related changes in tibiae and ulnae by a non-contact strain measurement technique called the digital image correlation (DIC) and the standard strain gage. A unique aspect of the study was to compare bones from the same animal to study variations in behavior with aging. This study was conducted using male and female C57Bl/6 mice at 6, 12 and 22 months of age (N=6-7 per age and sex) using three load levels. The DIC technique was able to detect a greater number of statistically significant differences in comparison to the strain gaging method. Male ulna showed significantly higher DIC strains compared to strains captured from strain gage at all three levels of load at 6 months and in the lowest load at 12 months. DIC measurements revealed that the ulna becomes stiffer with aging for both males and females, which resulted in 0.4 to 0.8 times reduced strains in the 22-month group compared to the 6 month group. Male tibia showed three-fold increased strains in the 22 months group at 11.5 N load compared to 6 months group (p<.05).
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Affiliation(s)
- Hammad Mumtaz
- University of Missouri-Kansas City, Department of Civil and Mechanical Engineering, Kansas, MO 64110, USA
| | - Nuria Lara-Castillo
- University of Missouri-Kansas City, School of Dentistry, Department of Oral and Craniofacial Sciences, Kansas, MO 64108, USA
| | - JoAnna M. Scott
- University of Missouri-Kansas City, Office of Research and Graduate Programs, Kansas, MO 64108, USA
| | - Mark Begonia
- Virginia Polytechnic Institute and State University, Biomedical Engineering and Mechanics, Blacksburg, VA 24061, USA
| | - Mark Dallas
- University of Missouri-Kansas City, School of Dentistry, Department of Oral and Craniofacial Sciences, Kansas, MO 64108, USA
| | - Mark L. Johnson
- University of Missouri-Kansas City, School of Dentistry, Department of Oral and Craniofacial Sciences, Kansas, MO 64108, USA
| | - Thiagarajan Ganesh
- University of Missouri-Kansas City, Department of Civil and Mechanical Engineering, Kansas, MO 64110, USA
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9
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Abstract
Chemokines are a family of small proteins, subdivided by their conserved cysteine residues and common structural features. Chemokines interact with their cognate G-protein-coupled receptors to elicit downstream signals that result in cell migration, proliferation, and survival. This review presents evidence for how the various CXC and CC subfamily chemokines influence bone hemostasis by acting on osteoclasts, osteoblasts, and progenitor cells. Also discussed are the ways in which chemokines contribute to bone loss as a result of inflammatory diseases such as rheumatoid arthritis, HIV infection, and periodontal infection. Both positive and negative effects of chemokines on bone formation and bone loss are presented. In addition, the role of chemokines in altering the bone microenvironment through effects on angiogenesis and tumor invasion is discussed. Very few therapeutic agents that influence bone formation by targeting chemokines or chemokine receptors are available, although a few are currently being evaluated.
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Affiliation(s)
- Annette Gilchrist
- Department of Pharmaceutical Sciences, Midwestern University, Downers Grove, IL, USA.
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10
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Cabahug-Zuckerman P, Liu C, Cai C, Mahaffey I, Norman SC, Cole W, Castillo AB. Site-Specific Load-Induced Expansion of Sca-1 +Prrx1 + and Sca-1 -Prrx1 + Cells in Adult Mouse Long Bone Is Attenuated With Age. JBMR Plus 2019; 3:e10199. [PMID: 31667455 PMCID: PMC6808224 DOI: 10.1002/jbm4.10199] [Citation(s) in RCA: 9] [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: 11/15/2018] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 02/04/2023] Open
Abstract
Aging is associated with significant bone loss and increased fracture risk, which has been attributed to a diminished response to anabolic mechanical loading. In adults, skeletal progenitors proliferate and differentiate into bone‐forming osteoblasts in response to increasing mechanical stimuli, though the effects of aging on this response are not well‐understood. Here we show that both adult and aged mice exhibit load‐induced periosteal bone formation, though the response is significantly attenuated with age. We also show that the acute response of adult bone to loading involves expansion of Sca‐1+Prrx1+ and Sca‐1−Prrx1+ cells in the periosteum. On the endosteal surface, loading enhances proliferation of both these cell populations, though the response is delayed by 2 days relative to the periosteal surface. In contrast to the periosteum and endosteum, the marrow does not exhibit increased proliferation of Sca‐1+Prrx1+ cells, but only of Sca‐1−Prrx1+ cells, underscoring fundamental differences in how the stem cell niche in distinct bone envelopes respond to mechanical stimuli. Notably, the proliferative response to loading is absent in aged bone even though there are similar baseline numbers of Prrx1 + cells in the periosteum and endosteum, suggesting that the proliferative capacity of progenitors is attenuated with age, and proliferation of the Sca‐1+Prrx1+ population is critical for load‐induced periosteal bone formation. These findings provide a basis for the development of novel therapeutics targeting these cell populations to enhance osteogenesis for overcoming age‐related bone loss. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Pamela Cabahug-Zuckerman
- Department of Orthopaedic Surgery NYU Langone Health, New York University New York NY USA.,Department of Biomedical Engineering Tandon School of Engineering, New York University New York NY USA.,Rehabilitation Research and Development Veterans Affairs New York Harbor Healthcare System New York NY USA
| | - Chao Liu
- Department of Orthopaedic Surgery NYU Langone Health, New York University New York NY USA.,Department of Biomedical Engineering Tandon School of Engineering, New York University New York NY USA.,Rehabilitation Research and Development Veterans Affairs New York Harbor Healthcare System New York NY USA
| | - Cinyee Cai
- Department of Orthopaedic Surgery NYU Langone Health, New York University New York NY USA.,Department of Biomedical Engineering Tandon School of Engineering, New York University New York NY USA
| | - Ian Mahaffey
- Rehabilitation Research and Development Veterans Affairs Palo Alto Healthcare System Palo Alto CA USA
| | - Stephanie C Norman
- Rehabilitation Research and Development Veterans Affairs Palo Alto Healthcare System Palo Alto CA USA
| | - Whitney Cole
- Rehabilitation Research and Development Veterans Affairs Palo Alto Healthcare System Palo Alto CA USA
| | - Alesha B Castillo
- Department of Orthopaedic Surgery NYU Langone Health, New York University New York NY USA.,Department of Biomedical Engineering Tandon School of Engineering, New York University New York NY USA.,Rehabilitation Research and Development Veterans Affairs New York Harbor Healthcare System New York NY USA
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11
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Sun D, Brodt MD, Zannit HM, Holguin N, Silva MJ. Evaluation of loading parameters for murine axial tibial loading: Stimulating cortical bone formation while reducing loading duration. J Orthop Res 2018; 36:682-691. [PMID: 28888055 PMCID: PMC5839947 DOI: 10.1002/jor.23727] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/31/2017] [Indexed: 02/04/2023]
Abstract
Classic studies in bone mechanobiology have established the importance of loading parameters on the anabolic response. Most of these early studies were done using loading methods not currently in favor, and using non-murine species. Our objective was to re-examine the effects of several loading parameters on the response of cortical bone using the contemporary murine axial tibial compression model. We subjected tibias of 5-month old, female C57Bl/6 mice to cyclic (4 Hz) mechanical loading and examined bone formation responses using dynamic and static histomorphometry. First, using a reference protocol of 1,200 cycles/day, 5 days/week for 2 weeks, we confirmed the significant influence of peak strain magnitude on periosteal mineralizing surface (Ps.MS/BS) and bone formation rate (Ps.BFR/BS) (p < 0.05, ANOVA). There was a significant induction of periosteal lamellar bone at a lower threshold of approx. -1,000 μϵ and a transition from lamellar-woven bone near -2,000 μϵ. In contrast, on the endocortical surface, bone formation indices did not exhibit a load magnitude-dependent response and no incidence of woven bone. Next, we found that reducing daily cycle number from 1,200 to 300 to 60 did not diminish the bone formation response (p > 0.05). On the other hand, reducing the daily frequency of loading from 5 consecutive days/week to 3 alternate days/week significantly diminished the periosteal response, from a loading-induced increase in Ps.MS/BS of 38% (loaded vs. control) for 5 days/week to only 15% for 3 days/week (p < 0.05). Finally, we determined that reducing the study duration from 2 to 1 weeks of loading did not affect bone formation outcomes. In conclusion, cyclic loading to -1,800 μϵ peak strain, at 4 Hz and 60 cycles/day for 5 consecutive days (1 week) induces an increase in periosteal lamellar bone formation with minimal incidence of woven bone in 5-month-old C57Bl/6 female mice. Our results provide a basis for reduction of loading duration (daily cycles and study length) without loss of anabolic effect as measured by dynamic histomorphometry. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:682-691, 2018.
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Affiliation(s)
- David Sun
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Michael D. Brodt
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Heather M. Zannit
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Nilsson Holguin
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri
| | - Matthew J. Silva
- Department of Orthopaedic Surgery, Washington University in Saint
Louis, Saint Louis, Missouri,Department of Biomedical Engineering, Washington University in Saint
Louis, Saint Louis, Missouri,Correspondence To: Matthew J. Silva, Ph.D.,
, Dept. of Orthopaedic Surgery/Campus Box
8233, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO
63110
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12
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Xu J, Chen Y, Liu Y, Zhang J, Kang Q, Ho K, Chai Y, Li G. Effect of SDF-1/Cxcr4 Signaling Antagonist AMD3100 on Bone Mineralization in Distraction Osteogenesis. Calcif Tissue Int 2017; 100:641-652. [PMID: 28303319 DOI: 10.1007/s00223-017-0249-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 01/30/2017] [Indexed: 01/16/2023]
Abstract
Distraction osteogenesis (DO) is a widely applied technique in orthopedics surgery, which involves rapid stem cell migration, homing, and differentiation. Interactions between the chemokine receptor Cxcr4 and its ligand, stromal derived factor-1 (SDF-1), regulate hematopoietic stem cell trafficking to the ischemic area and induce their subsequent differentiation. Here, we examined SDF-1 expression and further investigated the role of SDF-1/Cxcr4 signaling antagonist AMD3100 during bone regeneration in rat DO model. The results showed that expression levels of SDF-1 and osteogenic genes were higher in DO zones than in the fracture zones, and SDF-1 expression level was the highest at the termination of the distraction phase. Radiological, mechanical, and histological analyses demonstrated that the local administration of AMD3100 (400 μM) to DO rats significantly inhibited new bone formation. In the rat bone marrow mesenchymal stem cells culture, comparing to the group treated with osteogenic induction medium, AMD3100 supplement led to a considerable decrease in the expression of alkaline phosphatase and early osteogenic marker genes. However, the amount of calcium deposits in rat MSCs did not differ between the groups. Therefore, our study demonstrated that the DO process induced higher expression of SDF-1, which collated to rapid induction of callus formation. Local application of SDF-1/Cxcr4 signaling antagonist AMD3100 significantly inhibited bone mineralization and osteogenesis in DO, which may represent a potential therapeutic approach to the enhancement of bone consolidation in patients undergoing DO.
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Affiliation(s)
- Jia Xu
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Yuanfeng Chen
- Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 904, 9/F, Shatin, Hong Kong Sar, People's Republic of China
- Institute of Orthopedic Diseases and Department of Orthopedics, the First Affiliated Hospital, Jinan University, Guangzhou, People's Republic of China
| | - Yang Liu
- Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 904, 9/F, Shatin, Hong Kong Sar, People's Republic of China
| | - Jinfang Zhang
- Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 904, 9/F, Shatin, Hong Kong Sar, People's Republic of China
| | - Qinglin Kang
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Kiwai Ho
- Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 904, 9/F, Shatin, Hong Kong Sar, People's Republic of China
| | - Yimin Chai
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.
| | - Gang Li
- Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 904, 9/F, Shatin, Hong Kong Sar, People's Republic of China.
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13
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Kaku M, Kitami M, Rosales Rocabado JM, Ida T, Akiba Y, Uoshima K. Recruitment of bone marrow-derived cells to the periodontal ligament via the stromal cell-derived factor-1/C-X-C chemokine receptor type 4 axis. J Periodontal Res 2017; 52:686-694. [PMID: 28177531 DOI: 10.1111/jre.12433] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND/OBJECTIVES The periodontal ligament (PDL) is a non-mineralized connective tissue that exists between the alveolar bone and root surface cementum and plays important roles in tooth function. The PDL harbors a remarkable reserve of multipotent stem cells, which maintain various types of cells. However, the sources of these stem cells, other than their developmental origin, are not well understood. MATERIAL AND METHODS To elucidate the recruitment of bone marrow (BM)-derived stem cells in the PDL, green fluorescent protein (GFP)-expressing BM-derived cells were transplanted into the femoral BM of immunodeficient rats, and the distribution and expression of stem cell markers in the PDL were analyzed in vivo. To evaluate the functional significance of BM-derived cells to the PDL, tooth replantation was performed and the expression of stromal cell-derived factor (SDF)-1, a critical chemotactic signal for mesenchymal stem cell recruitment, was analyzed. To confirm the SDF-1-dependency of BM-derived cell migration to the PDL, PDL-conditioned medium (CM) was prepared, and BM-derived cell migration was analyzed using a transwell culture system. RESULTS Four weeks after cell transplantation, GFP-positive cells were detected in the PDL, and some of them were also positive for stem cell markers (i.e., CD29, SSEA4, and αSMA). Seven days after tooth replantation, the number of GFP- and SDF-1-positive cells significantly increased in PDL. Concurrently, the concentration of SDF-1 and the number of colony-forming units of fibroblasts in peripheral blood were increased. BM-derived cell migration increased in PDL-CM and was inhibited by an inhibitor of C-X-C chemokine receptor type 4 (CXCR4), an SDF-1 receptor. CONCLUSION These results indicate that stem cells and their progeny in PDL are not only derived from their developmental origin but are also supplied from the BM via the blood as the need arises. Moreover, this BM-derived cell recruitment appears to be regulated, at least partially, by the SDF-1/CXCR4 axis.
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Affiliation(s)
- M Kaku
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - M Kitami
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - J M Rosales Rocabado
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - T Ida
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Y Akiba
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - K Uoshima
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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14
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Govey PM, Zhang Y, Donahue HJ. Mechanical Loading Attenuates Radiation-Induced Bone Loss in Bone Marrow Transplanted Mice. PLoS One 2016; 11:e0167673. [PMID: 27936104 PMCID: PMC5147933 DOI: 10.1371/journal.pone.0167673] [Citation(s) in RCA: 9] [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: 08/11/2016] [Accepted: 11/20/2016] [Indexed: 12/16/2022] Open
Abstract
Exposure of bone to ionizing radiation, as occurs during radiotherapy for some localized malignancies and blood or bone marrow cancers, as well as during space travel, incites dose-dependent bone morbidity and increased fracture risk. Rapid trabecular and endosteal bone loss reflects acutely increased osteoclastic resorption as well as decreased bone formation due to depletion of osteoprogenitors. Because of this dysregulation of bone turnover, bone’s capacity to respond to a mechanical loading stimulus in the aftermath of irradiation is unknown. We employed a mouse model of total body irradiation and bone marrow transplantation simulating treatment of hematologic cancers, hypothesizing that compression loading would attenuate bone loss. Furthermore, we hypothesized that loading would upregulate donor cell presence in loaded tibias due to increased engraftment and proliferation. We lethally irradiated 16 female C57Bl/6J mice at age 16 wks with 10.75 Gy, then IV-injected 20 million GFP(+) total bone marrow cells. That same day, we initiated 3 wks compression loading (1200 cycles 5x/wk, 10 N) in the right tibia of 10 of these mice while 6 mice were irradiated, non-mechanically-loaded controls. As anticipated, before-and-after microCT scans demonstrated loss of trabecular bone (-48.2% Tb.BV/TV) and cortical thickness (-8.3%) at 3 wks following irradiation. However, loaded bones lost 31% less Tb.BV/TV and 8% less cortical thickness (both p<0.001). Loaded bones also had significant increases in trabecular thickness and tissue mineral densities from baseline. Mechanical loading did not affect donor cell engraftment. Importantly, these results demonstrate that both cortical and trabecular bone exposed to high-dose therapeutic radiation remain capable of an anabolic response to mechanical loading. These findings inform our management of bone health in cases of radiation exposure.
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Affiliation(s)
- Peter M. Govey
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA, United States of America
- Department of Biomedical Engineering, Penn State College of Engineering, University Park, PA, United States of America
| | - Yue Zhang
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA, United States of America
- Department of Biomedical Engineering, Virginia Commonwealth College of Engineering, Richmond, VA, United States of America
| | - Henry J. Donahue
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA, United States of America
- Department of Biomedical Engineering, Penn State College of Engineering, University Park, PA, United States of America
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, United States of America
- Department of Biomedical Engineering, Virginia Commonwealth College of Engineering, Richmond, VA, United States of America
- * E-mail:
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15
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Glorie L, D'Haese PC, Verhulst A. Boning up on DPP4, DPP4 substrates, and DPP4-adipokine interactions: Logical reasoning and known facts about bone related effects of DPP4 inhibitors. Bone 2016; 92:37-49. [PMID: 27535784 DOI: 10.1016/j.bone.2016.08.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/29/2016] [Accepted: 08/11/2016] [Indexed: 12/19/2022]
Abstract
Dipeptidyl peptidase 4 (DPP4) is a conserved exopeptidase with an important function in protein regulation. The activity of DPP4, an enzyme which can either be anchored to the plasma membrane or circulate free in the extracellular compartment, affects the glucose metabolism, cellular signaling, migration and differentiation, oxidative stress and the immune system. DPP4 is also expressed on the surface of osteoblasts, osteoclasts and osteocytes, and was found to play a role in collagen metabolism. Many substrates of DPP4 have an established role in bone metabolism, among which are incretins, gastrointestinal peptides and neuropeptides. In general, their effects favor bone formation, but some effects are complex and have not been completely elucidated. DPP4 and some of its substrates are known to interact with adipokines, playing an essential role in the energy metabolism. The prolongation of the half-life of incretins through DPP4 inhibition led to the development of these inhibitors to improve glucose tolerance in diabetes. Current literature indicates that the inhibition of DPP4 activity might also result in a beneficial effect on the bone metabolism, but the long-term effect of DPP4 inhibition on fracture outcome has not been entirely established. Diabetic as well as postmenopausal osteoporosis is associated with an increased activity of DPP4, as well as a shift in the expression levels of DPP4 substrates, their receptors, and adipokines. The interactions between these factors and their relationship in bone metabolism are therefore an interesting field of study.
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Affiliation(s)
- Lorenzo Glorie
- Laboratory of Pathophysiology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
| | - Patrick C D'Haese
- Laboratory of Pathophysiology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Anja Verhulst
- Laboratory of Pathophysiology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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16
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Liu C, Cui X, Ackermann TM, Flamini V, Chen W, Castillo AB. Osteoblast-derived paracrine factors regulate angiogenesis in response to mechanical stimulation. Integr Biol (Camb) 2016; 8:785-94. [PMID: 27332785 PMCID: PMC8274385 DOI: 10.1039/c6ib00070c] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Angiogenesis is a process by which new blood vessels emerge from existing vessels through endothelial cell sprouting, migration, proliferation, and tubule formation. Angiogenesis during skeletal growth, homeostasis and repair is a complex and incompletely understood process. As the skeleton adapts to mechanical loading, we hypothesized that mechanical stimulation regulates "osteo-angio" crosstalk in the context of angiogenesis. We showed that conditioned media (CM) from osteoblasts exposed to fluid shear stress enhanced endothelial cell proliferation and migration, but not tubule formation, relative to CM from static cultures. Endothelial cell sprouting was studied using a dual-channel collagen gel-based microfluidic device that mimics vessel geometry. Static CM enhanced endothelial cell sprouting frequency, whereas loaded CM significantly enhanced both frequency and length. Both sprouting frequency and length were significantly enhanced in response to factors released from osteoblasts exposed to fluid shear stress in an adjacent channel. Osteoblasts released angiogenic factors, of which osteopontin, PDGF-AA, IGBP-2, MCP-1, and Pentraxin-3 were upregulated in response to mechanical loading. These data suggest that in vivo mechanical forces regulate angiogenesis in bone by modulating "osteo-angio" crosstalk through release of paracrine factors, which we term "osteokines".
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Affiliation(s)
- Chao Liu
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA. and Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY 10003, USA
| | - Xin Cui
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA.
| | - Thomas M Ackermann
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA.
| | - Vittoria Flamini
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA.
| | - Weiqiang Chen
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA.
| | - Alesha B Castillo
- Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, USA. and Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY 10003, USA
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17
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Yang K, Wu Y, Cheng P, Zhang J, Yang C, Pi B, Ye Y, You H, Chen A, Xu T, Guo F, Qi J. YAP and ERK mediated mechanical strain-induced cell cycle progression through RhoA and cytoskeletal dynamics in rat growth plate chondrocytes. J Orthop Res 2016; 34:1121-9. [PMID: 26694636 DOI: 10.1002/jor.23138] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 12/14/2015] [Indexed: 02/04/2023]
Abstract
Yes-associated protein (YAP) and extracellular signal-regulated kinase (ERK) have been considered as key regulators in tissue homeostasis, organ development, and tumor formation. However, the roles of YAP and ERK in the mediating strain mechanosensing in the growth plate cartilage have not been determined. In this study, chondrocytes obtained from the growth plate cartilage of 2-week-old Sprague-Dawley rats were subjected to the mechanical strain with different magnitudes and durations at a frequency of 0.5 Hz. We found that YAP and ERK activation in response to mechanical strain was time and magnitude dependent. Pretreatment with a RhoA inhibitor (C3 toxin) or a microfilament cytoskeleton disrupting reagent (cytochalasin D) could suppress their activation. In addition, activated YAP and ERK were able to induce cell cycle progression by up-regulating the expression of cell cycle-related genes. These results shed new light on the function of YAP and ERK in mechanical strain-promoted growth plate development. Our results also provided evidence that RhoA and cytoskeletal dynamics are required for this mechanotransduction. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1121-1129, 2016.
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Affiliation(s)
- Kaixiang Yang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China.,Department of Orthopedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, 215006, Jiangsu Province, P. R. China
| | - Yingxing Wu
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Peng Cheng
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Jinming Zhang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Chengyuan Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, 215006, Jiangsu Province, P. R. China
| | - Bin Pi
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, 215006, Jiangsu Province, P. R. China
| | - Yaping Ye
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Hongbo You
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Anmin Chen
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Tao Xu
- Department of Rehabilitation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Fengjing Guo
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
| | - Jun Qi
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei Province, P. R. China
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18
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Abstract
Mechanical loading is a potent anabolic regulator of bone mass, and the first line of defense for bone loss is weight-bearing exercise. Likewise, protected weight bearing is the first prescribed physical therapy following orthopedic reconstructive surgery. In both cases, enhancement of new bone formation is the goal. Our understanding of the physical cues, mechanisms of force sensation, and the subsequent cellular response will help identify novel physical and therapeutic treatments for age- and disuse-related bone loss, delayed- and nonunion fractures, and significant bony defects. This review highlights important new insights into the principles and mechanisms governing mechanical adaptation of the skeleton during homeostasis and repair and ends with a summary of clinical implications stemming from our current understanding of how bone adapts to biophysical force.
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19
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Myers TJ, Longobardi L, Willcockson H, Temple JD, Tagliafierro L, Ye P, Li T, Esposito A, Moats-Staats BM, Spagnoli A. BMP2 Regulation of CXCL12 Cellular, Temporal, and Spatial Expression is Essential During Fracture Repair. J Bone Miner Res 2015; 30:2014-27. [PMID: 25967044 PMCID: PMC4970512 DOI: 10.1002/jbmr.2548] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 04/27/2015] [Accepted: 05/05/2015] [Indexed: 12/30/2022]
Abstract
The cellular and humoral responses that orchestrate fracture healing are still elusive. Here we report that bone morphogenic protein 2 (BMP2)-dependent fracture healing occurs through a tight control of chemokine C-X-C motif-ligand-12 (CXCL12) cellular, spatial, and temporal expression. We found that the fracture repair process elicited an early site-specific response of CXCL12(+)-BMP2(+) endosteal cells and osteocytes that was not present in unfractured bones and gradually decreased as healing progressed. Absence of a full complement of BMP2 in mesenchyme osteoprogenitors (BMP2(cKO/+)) prevented healing and led to a dysregulated temporal and cellular upregulation of CXCL12 expression associated with a deranged angiogenic response. Healing was rescued when BMP2(cKO/+) mice were systemically treated with AMD3100, an antagonist of CXCR4 and agonist for CXCR7 both receptors for CXCL12. We further found that mesenchymal stromal cells (MSCs), capable of delivering BMP2 at the endosteal site, restored fracture healing when transplanted into BMP2(cKO/+) mice by rectifying the CXCL12 expression pattern. Our in vitro studies showed that in isolated endosteal cells, BMP2, while inducing osteoblastic differentiation, stimulated expression of pericyte markers that was coupled with a decrease in CXCL12. Furthermore, in isolated BMP2(cKO/cKO) endosteal cells, high expression levels of CXCL12 inhibited osteoblastic differentiation that was restored by AMD3100 treatment or coculture with BMP2-expressing MSCs that led to an upregulation of pericyte markers while decreasing platelet endothelial cell adhesion molecule (PECAM). Taken together, our studies show that following fracture, a CXCL12(+)-BMP2(+) perivascular cell population is recruited along the endosteum, then a timely increase of BMP2 leads to downregulation of CXCL12 that is essential to determine the fate of the CXCL12(+)-BMP2(+) to osteogenesis while departing their supportive role to angiogenesis. Our findings have far-reaching implications for understanding mechanisms regulating the selective recruitment of distinct cells into the repairing niches and the development of novel pharmacological (by targeting BMP2/CXCL12) and cellular (MSCs, endosteal cells) interventions to promote fracture healing.
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Affiliation(s)
- Timothy J Myers
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lara Longobardi
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Helen Willcockson
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joseph D Temple
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Pediatrics, Rush University Medical Center, Chicago, IL, USA
| | - Lidia Tagliafierro
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ping Ye
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tieshi Li
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Pediatrics, Rush University Medical Center, Chicago, IL, USA
| | - Alessandra Esposito
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Pediatrics, Rush University Medical Center, Chicago, IL, USA
| | - Billie M Moats-Staats
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Anna Spagnoli
- Division of Endocrinology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Pediatrics, Rush University Medical Center, Chicago, IL, USA
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20
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21
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Norman SC, Wagner DW, Beaupre GS, Castillo AB. Comparison of three methods of calculating strain in the mouse ulna in exogenous loading studies. J Biomech 2014; 48:53-8. [PMID: 25443882 DOI: 10.1016/j.jbiomech.2014.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 10/24/2022]
Abstract
Axial compression of mouse limbs is commonly used to induce bone formation in a controlled, non-invasive manner. Determination of peak strains caused by loading is central to interpreting results. Load-strain calibration is typically performed using uniaxial strain gauges attached to the diaphyseal, periosteal surface of a small number of sacrificed animals. Strain is measured as the limb is loaded to a range of physiological loads known to be anabolic to bone. The load-strain relationship determined by this subgroup is then extrapolated to a larger group of experimental mice. This method of strain calculation requires the challenging process of strain gauging very small bones which is subject to variability in placement of the strain gauge. We previously developed a method to estimate animal-specific periosteal strain during axial ulnar loading using an image-based computational approach that does not require strain gauges. The purpose of this study was to compare the relationship between load-induced bone formation rates and periosteal strain at ulnar midshaft using three different methods to estimate strain: (A) Nominal strain values based solely on load-strain calibration; (B) Strains calculated from load-strain calibration, but scaled for differences in mid-shaft cross-sectional geometry among animals; and (C) An alternative image-based computational method for calculating strains based on beam theory and animal-specific bone geometry. Our results show that the alternative method (C) provides comparable correlation between strain and bone formation rates in the mouse ulna relative to the strain gauge-dependent methods (A and B), while avoiding the need to use strain gauges.
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Affiliation(s)
- Stephanie C Norman
- Rehabilitation R&D, VA Palo Alto Health Care System, Palo Alto, CA, United States.
| | - David W Wagner
- Rehabilitation R&D, VA Palo Alto Health Care System, Palo Alto, CA, United States
| | - Gary S Beaupre
- Rehabilitation R&D, VA Palo Alto Health Care System, Palo Alto, CA, United States; Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Alesha B Castillo
- Rehabilitation R&D, VA Palo Alto Health Care System, Palo Alto, CA, United States; Department of Surgery, Stanford University School of Medicine, Stanford, CA, United States; Department of Mechanical and Aerospace Engineering, New York University, NY, United States
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22
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Kitase Y, Lee S, Gluhak-Heinrich J, Johnson ML, Harris SE, Bonewald LF. CCL7 is a protective factor secreted by mechanically loaded osteocytes. J Dent Res 2014; 93:1108-15. [PMID: 25274752 PMCID: PMC4212466 DOI: 10.1177/0022034514553008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 01/10/2023] Open
Abstract
In a search for factors up-regulated by mechanical strain in osteocytes, we discovered that chemokine (C-C motif) ligand 7 (CCL7), a chemotactic myokine, was highly expressed in MLO-Y4 osteocyte-like cells. Although MLO-Y4 cells secrete potent chemotactic factors for osteoclast precursors, CCL7 was not responsible for this activity. CCL7 was increased in osteocytes in response to tooth movement in vivo. Since mechanical loading plays a crucial role in maintaining osteocyte viability, CCL7 was tested for protective activity and found to be protective against cell death induced by dexamethasone and etoposide. CCL7 specific antibody partially, but in combination with indomethacin, completely abrogated the protective effects of fluid flow shear stress against dexamethasone-induced cell death. CCL7 activated the β-catenin pathway through phosphorylation of glycogen synthase kinase 3 (GSK-3), suggesting that this pathway is responsible for the observed protective effects. A related cytokine, CCL2, also produced by MLO-Y4 cells but not regulated by mechanical loading, proved to be more potent and protected against cell death induced by not only dexamethasone, but also by Tumor Necrosis Factor α (TNFα). Whereas osteocytes may produce CCL2 in constitutively low levels, a major function of mechanically induced CCL7 may be to selectively protect osteocytes in an autocrine manner against glucocorticoid-induced cell death.
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Affiliation(s)
- Y Kitase
- Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, USA
| | - S Lee
- Endocrinology, Internal Medicine, Eulji University School of Medicine, Daejeon City, Republic of Korea
| | | | - M L Johnson
- Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, USA
| | - S E Harris
- Periodontics and Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - L F Bonewald
- Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO, USA
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23
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Pandey MK, Kale VP, Song C, Sung SS, Sharma AK, Talamo G, Dovat S, Amin SG. Gambogic acid inhibits multiple myeloma mediated osteoclastogenesis through suppression of chemokine receptor CXCR4 signaling pathways. Exp Hematol 2014; 42:883-96. [PMID: 25034231 DOI: 10.1016/j.exphem.2014.07.261] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 06/11/2014] [Accepted: 07/05/2014] [Indexed: 11/17/2022]
Abstract
Bone disease, characterized by the presence of lytic lesions and osteoporosis is the hallmark of multiple myeloma (MM). Stromal cell-derived factor 1α (SDF-1α) and its receptor, CXC chemokine receptor 4 (CXCR4), has been implicated as a regulator of bone resorption, suggesting that agents that can suppress SDF1α/CXCR4 signaling might inhibit osteoclastogenesis, a process closely linked to bone resorption. We, therefore, investigated whether gambogic acid (GA), a xanthone, could inhibit CXCR4 signaling and suppress osteoclastogenesis induced by MM cells. Through docking studies we predicted that GA directly interacts with CXCR4. This xanthone down-regulates the expression of CXCR4 on MM cells in a dose- and time-dependent manner. The down-regulation of CXCR4 was not due to proteolytic degradation, but rather GA suppresses CXCR4 mRNA expression by inhibiting nuclear factor-kappa B (NF-κB) DNA binding. This was further confirmed by quantitative chromatin immunoprecipitation assay, as GA inhibits p65 binding at the CXCR4 promoter. GA suppressed SDF-1α-induced chemotaxis of MM cells and downstream signaling of CXCR4 by inhibiting phosphorylation of Akt, p38, and Erk1/2 in MM cells. GA abrogated the RANKL-induced differentiation of macrophages to osteoclasts in a dose- and time-dependent manner. In addition, we found that MM cells induced differentiation of macrophages to osteoclasts, and that GA suppressed this process. Importantly, suppression of osteoclastogenesis by GA was mediated through IL-6 inhibition. Overall, our results show that GA is a novel inhibitor of CXCR4 expression and has a strong potential to suppress osteoclastogenesis mediated by MM cells.
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Affiliation(s)
- Manoj K Pandey
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA.
| | - Vijay P Kale
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA
| | - Chunhua Song
- Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA
| | - Shen-shu Sung
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA
| | - Arun K Sharma
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA
| | - Giampaolo Talamo
- Department of Medicine, Pennsylvania State University College of Medicine, Hershey, PA
| | - Sinisa Dovat
- Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA
| | - Shantu G Amin
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA
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24
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Villalvilla A, Gomez R, Roman-Blas JA, Largo R, Herrero-Beaumont G. SDF-1 signaling: a promising target in rheumatic diseases. Expert Opin Ther Targets 2014; 18:1077-87. [DOI: 10.1517/14728222.2014.930440] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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25
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Govey PM, Jacobs JM, Tilton SC, Loiselle AE, Zhang Y, Freeman WM, Waters KM, Karin NJ, Donahue HJ. Integrative transcriptomic and proteomic analysis of osteocytic cells exposed to fluid flow reveals novel mechano-sensitive signaling pathways. J Biomech 2014; 47:1838-45. [PMID: 24720889 DOI: 10.1016/j.jbiomech.2014.03.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 03/11/2014] [Accepted: 03/11/2014] [Indexed: 01/01/2023]
Abstract
Osteocytes, positioned within bone׳s porous structure, are subject to interstitial fluid flow upon whole bone loading. Such fluid flow is widely theorized to be a mechanical signal transduced by osteocytes, initiating a poorly understood cascade of signaling events mediating bone adaptation to mechanical load. The objective of this study was to examine the time course of flow-induced changes in osteocyte gene transcript and protein levels using high-throughput approaches. Osteocyte-like MLO-Y4 cells were subjected to 2h of oscillating fluid flow (1Pa peak shear stress) and analyzed following 0, 2, 8, and 24h post-flow incubation. Transcriptomic microarray analysis, followed by gene ontology pathway analysis, demonstrated fluid flow regulation of genes consistent with both known and unknown metabolic and inflammatory responses in bone. Additionally, two of the more highly up-regulated gene products - chemokines Cxcl1 and Cxcl2, supported by qPCR - have not previously been reported as responsive to fluid flow. Proteomic analysis demonstrated greatest up-regulation of the ATP-producing enzyme NDK, calcium-binding Calcyclin, and G protein-coupled receptor kinase 6. Finally, an integrative pathway analysis merging fold changes in transcript and protein levels predicted signaling nodes not directly detected at the sampled time points, including transcription factors c-Myc, c-Jun, and RelA/NF-κB. These results extend our knowledge of the osteocytic response to fluid flow, most notably up-regulation of Cxcl1 and Cxcl2 as possible paracrine agents for osteoblastic and osteoclastic recruitment. Moreover, these results demonstrate the utility of integrative, high-throughput approaches in place of a traditional candidate approach for identifying novel mechano-sensitive signaling molecules.
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Affiliation(s)
- Peter M Govey
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Jon M Jacobs
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Susan C Tilton
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Alayna E Loiselle
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Yue Zhang
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Willard M Freeman
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Katrina M Waters
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Norman J Karin
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Henry J Donahue
- Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA.
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