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Bachmeier AT, Euler E, Bader R, Böcker W, Thaller PH. Novel approach to estimate distraction forces in distraction osteogenesis and application in the human lower leg. J Mech Behav Biomed Mater 2022; 128:105133. [PMID: 35217291 DOI: 10.1016/j.jmbbm.2022.105133] [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: 11/09/2020] [Revised: 01/18/2022] [Accepted: 02/11/2022] [Indexed: 11/19/2022]
Abstract
PURPOSE In distraction osteogenesis (DO) of long bones, new bone tissue is distracted to lengthen limbs or reconstruct bone defects. However, mechanical boundary conditions in human application such as arising forces are mainly based on limited empirical data. Our aim was the numerical determination of the callus distraction force (CDF) and the total distraction force (TDF) during DO in the tibia of adults to advance the understanding of callus tissue behavior and optimize DO procedures. METHOD We implemented a mathematical model based on an animal experiment to enable the calculation of forces arising while distracting callus tissue, excluding the influence of surrounding soft tissue (muscles, skin etc.). The CDF progression for the distraction period was calculated using the implemented model and varying distraction parameters (initial gap, area, step size, time interval, length). Further, we estimated the CDF based on reported forces in humans and compared the results to our model predictions. In addition, we calculated the TDF based on our CDF predictions in combination with reported resisting forces due to soft tissue presence in human cadavers. Finally, we compared the progressions to in vivo TDF measurements for validation. RESULTS Due to relaxation, a peak and resting CDF is observable for each distraction step. Our biomechanical results show a non-linear degressive increase of the resting and peak CDF at the beginning and a steady non-linear increase thereafter. The calculated resting and peak CDF in the tibial metaphysis ranged from 0.00075 to 0.0089 N and 0.22-2.6 N at the beginning as well as 20-25 N and 70-75 N at the end of distraction. The comparison to in vivo data showed the plausibility of our predictions and resulted in a 10-33% and 10-23% share of resting CDF in the total resting force for bone transport and elongation, respectively. Further, the percentage of peak CDF in total peak force was found to be 29-58% and 27-55% for bone transport and elongation, respectively. Moreover, our TDF predictions were valid based on the comparison to in vivo forces and resulted in a degressive increase from 6 to 125 N for the peak TDF and from 5 to 76 N for the resting TDF. CONCLUSION Our approach enables the estimation of forces arising due to the distraction of callus tissue in humans and results in plausible force progressions as well as absolute force values for the callus distraction force during DO. In combination with measurements of resisting forces due to the presence of soft tissue, the total distraction force in DO may also be evaluated. We thus propose the application of this method to approximate the behavior of mechanical callus properties during DO in humans as an alternative to in vivo measurements.
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Affiliation(s)
- A T Bachmeier
- 3D-Surgery, Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany; Biomechanics and Implant Technology Research Laboratory, University Medicine Rostock, Rostock, Germany.
| | - E Euler
- Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
| | - R Bader
- Biomechanics and Implant Technology Research Laboratory, University Medicine Rostock, Rostock, Germany
| | - W Böcker
- Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
| | - P H Thaller
- 3D-Surgery, Department of General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany
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Wei Z, Schnellmann R, Pruitt HC, Gerecht S. Hydrogel Network Dynamics Regulate Vascular Morphogenesis. Cell Stem Cell 2020; 27:798-812.e6. [PMID: 32931729 PMCID: PMC7655724 DOI: 10.1016/j.stem.2020.08.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 06/08/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022]
Abstract
Matrix dynamics influence how individual cells develop into complex multicellular tissues. Here, we develop hydrogels with identical polymer components but different crosslinking capacities to enable the investigation of mechanisms underlying vascular morphogenesis. We show that dynamic (D) hydrogels increase the contractility of human endothelial colony-forming cells (hECFCs), promote the clustering of integrin β1, and promote the recruitment of vinculin, leading to the activation of focal adhesion kinase (FAK) and metalloproteinase expression. This leads to the robust assembly of vasculature and the deposition of new basement membrane. We also show that non-dynamic (N) hydrogels do not promote FAK signaling and that stiff D- and N-hydrogels are constrained for vascular morphogenesis. Furthermore, D-hydrogels promote hECFC microvessel formation and angiogenesis in vivo. Our results indicate that cell contractility mediates integrin signaling via inside-out signaling and emphasizes the importance of matrix dynamics in vascular tissue formation, thus informing future studies of vascularization and tissue engineering applications.
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Affiliation(s)
- Zhao Wei
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology, Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Rahel Schnellmann
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology, Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Hawley C Pruitt
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology, Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sharon Gerecht
- Department of Chemical and Biomolecular Engineering, The Institute for NanoBioTechnology, Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Viscoelasticity in natural tissues and engineered scaffolds for tissue reconstruction. Acta Biomater 2019; 97:74-92. [PMID: 31400521 DOI: 10.1016/j.actbio.2019.08.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/23/2019] [Accepted: 08/06/2019] [Indexed: 02/05/2023]
Abstract
Viscoelasticity of living tissues plays a critical role in tissue homeostasis and regeneration, and its implication in disease development and progression is being recognized recently. In this review, we first explored the state of knowledge regarding the potential application of tissue viscoelasticity in disease diagnosis. In order to better characterize viscoelasticity with local resolution and non-invasiveness, emerging characterization methods have been developed with the potential to be supplemented to existing facilities. To understand cellular responses to matrix viscoelastic behaviors in vitro, hydrogels made of natural polymers have been developed and the relationships between their molecular structure and viscoelastic behaviors, are elucidated. Moreover, how cells perceive the viscoelastic microenvironment and cellular responses including cell attachment, spreading, proliferation, differentiation and matrix production, have been discussed. Finally, some future perspective on an integrated mechanobiological comprehension of the viscoelastic behaviors involved in tissue homeostasis, cellular responses and biomaterial design are highlighted. STATEMENT OF SIGNIFICANCE: Tissue- or organ-scale viscoelastic behavior is critical for homeostasis, and the molecular basis and cellular responses of viscoelastic materials at micro- or nano-scale are being recognized recently. We summarized the potential applications of viscoelasticity in disease diagnosis enabled by emerging non-invasive characterization technologies, and discussed the underlying mechanism of viscoelasticity of hydrogels and current understandings of cell regulatory functions of them. With a growing understanding of the molecular basis of hydrogel viscoelasticity and recognition of its regulatory functions on cell behaviors, it is important to bring the clinical insights on how these characterization technologies and engineered materials may contribute to disease diagnosis and treatment. This review explains the basics in characterizing viscoelasticity with our hope to bridge the gap between basic research and clinical applications.
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Volume expansion and TRPV4 activation regulate stem cell fate in three-dimensional microenvironments. Nat Commun 2019; 10:529. [PMID: 30705265 PMCID: PMC6355972 DOI: 10.1038/s41467-019-08465-x] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 01/11/2019] [Indexed: 12/19/2022] Open
Abstract
For mesenchymal stem cells (MSCs) cultured in three dimensional matrices, matrix remodeling is associated with enhanced osteogenic differentiation. However, the mechanism linking matrix remodeling in 3D to osteogenesis of MSCs remains unclear. Here, we find that MSCs in viscoelastic hydrogels exhibit volume expansion during cell spreading, and greater volume expansion is associated with enhanced osteogenesis. Restriction of expansion by either hydrogels with slow stress relaxation or increased osmotic pressure diminishes osteogenesis, independent of cell morphology. Conversely, induced expansion by hypoosmotic pressure accelerates osteogenesis. Volume expansion is mediated by activation of TRPV4 ion channels, and reciprocal feedback between TRPV4 activation and volume expansion controls nuclear localization of RUNX2, but not YAP, to promote osteogenesis. This work demonstrates the role of cell volume in regulating cell fate in 3D culture, and identifies TRPV4 as a molecular sensor of matrix viscoelasticity that regulates osteogenic differentiation. For mesenchymal stem cells (MSCs), matrix remodeling is associated with enhanced osteogenic differentiation. Here authors find that MSCs in viscoelastic hydrogels exhibit volume expansion during cell spreading, and greater volume expansion is associated with enhanced osteogenesis.
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Holle AW, Young JL, Van Vliet KJ, Kamm RD, Discher D, Janmey P, Spatz JP, Saif T. Cell-Extracellular Matrix Mechanobiology: Forceful Tools and Emerging Needs for Basic and Translational Research. NANO LETTERS 2018; 18:1-8. [PMID: 29178811 PMCID: PMC5842374 DOI: 10.1021/acs.nanolett.7b04982] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Extracellular biophysical cues have a profound influence on a wide range of cell behaviors, including growth, motility, differentiation, apoptosis, gene expression, adhesion, and signal transduction. Cells not only respond to definitively mechanical cues from the extracellular matrix (ECM) but can also sometimes alter the mechanical properties of the matrix and hence influence subsequent matrix-based cues in both physiological and pathological processes. Interactions between cells and materials in vitro can modify cell phenotype and ECM structure, whether intentionally or inadvertently. Interactions between cell and matrix mechanics in vivo are of particular importance in a wide variety of disorders, including cancer, central nervous system injury, fibrotic diseases, and myocardial infarction. Both the in vitro and in vivo effects of this coupling between mechanics and biology hold important implications for clinical applications.
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Affiliation(s)
- Andrew W Holle
- Department of Cellular Biophysics, Max Planck Institute for Medical Research , Jahnstraße 29, 69120 Heidelberg, Germany
- Institute of Physical Chemistry, University of Heidelberg , 69117 Heidelberg, Germany
| | - Jennifer L Young
- Department of Cellular Biophysics, Max Planck Institute for Medical Research , Jahnstraße 29, 69120 Heidelberg, Germany
- Institute of Physical Chemistry, University of Heidelberg , 69117 Heidelberg, Germany
| | - Krystyn J Van Vliet
- BioSystems & Micromechanics IRG, Singapore-MIT Alliance in Research and Technology , Singapore
| | - Roger D Kamm
- BioSystems & Micromechanics IRG, Singapore-MIT Alliance in Research and Technology , Singapore
| | | | | | - Joachim P Spatz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research , Jahnstraße 29, 69120 Heidelberg, Germany
- Institute of Physical Chemistry, University of Heidelberg , 69117 Heidelberg, Germany
| | - Taher Saif
- Department of Mechanical Sciences and Engineering, University of Illinois at Urbana-Champaign , 1206 West Green Street, Urbana, Illinois 61801, United States
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Vining KH, Mooney DJ. Mechanical forces direct stem cell behaviour in development and regeneration. Nat Rev Mol Cell Biol 2017; 18:728-742. [PMID: 29115301 PMCID: PMC5803560 DOI: 10.1038/nrm.2017.108] [Citation(s) in RCA: 853] [Impact Index Per Article: 121.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Stem cells and their local microenvironment, or niche, communicate through mechanical cues to regulate cell fate and cell behaviour and to guide developmental processes. During embryonic development, mechanical forces are involved in patterning and organogenesis. The physical environment of pluripotent stem cells regulates their self-renewal and differentiation. Mechanical and physical cues are also important in adult tissues, where adult stem cells require physical interactions with the extracellular matrix to maintain their potency. In vitro, synthetic models of the stem cell niche can be used to precisely control and manipulate the biophysical and biochemical properties of the stem cell microenvironment and to examine how the mode and magnitude of mechanical cues, such as matrix stiffness or applied forces, direct stem cell differentiation and function. Fundamental insights into the mechanobiology of stem cells also inform the design of artificial niches to support stem cells for regenerative therapies.
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Affiliation(s)
- Kyle H. Vining
- Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - David J. Mooney
- Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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Abstract
This mini-review discusses newly developed approaches to tuning hydrogel viscoelasticity and recent studies demonstrating an impact of viscoelasticity on cells.
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Affiliation(s)
- Ovijit Chaudhuri
- Department of Mechanical Engineering
- Stanford University
- Stanford
- USA
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Chaudhuri O, Gu L, Klumpers D, Darnell M, Bencherif SA, Weaver JC, Huebsch N, Lee HP, Lippens E, Duda GN, Mooney DJ. Hydrogels with tunable stress relaxation regulate stem cell fate and activity. NATURE MATERIALS 2016; 15:326-34. [PMID: 26618884 PMCID: PMC4767627 DOI: 10.1038/nmat4489] [Citation(s) in RCA: 1312] [Impact Index Per Article: 164.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 10/26/2015] [Indexed: 05/18/2023]
Abstract
Natural extracellular matrices (ECMs) are viscoelastic and exhibit stress relaxation. However, hydrogels used as synthetic ECMs for three-dimensional (3D) culture are typically elastic. Here, we report a materials approach to tune the rate of stress relaxation of hydrogels for 3D culture, independently of the hydrogel's initial elastic modulus, degradation, and cell-adhesion-ligand density. We find that cell spreading, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) are all enhanced in cells cultured in gels with faster relaxation. Strikingly, MSCs form a mineralized, collagen-1-rich matrix similar to bone in rapidly relaxing hydrogels with an initial elastic modulus of 17 kPa. We also show that the effects of stress relaxation are mediated by adhesion-ligand binding, actomyosin contractility and mechanical clustering of adhesion ligands. Our findings highlight stress relaxation as a key characteristic of cell-ECM interactions and as an important design parameter of biomaterials for cell culture.
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Affiliation(s)
- Ovijit Chaudhuri
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Luo Gu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
| | - Darinka Klumpers
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
- Dept. Orthopedic Surgery, Research Institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
| | - Max Darnell
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
| | - Sidi A. Bencherif
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
| | - James C. Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
| | - Nathaniel Huebsch
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Gladstone Institute of Cardiovascular Disease, San Francisco
| | - Hong-pyo Lee
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Evi Lippens
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
- Julius Wolff Institute, Charité – Universitätsmedizin Berlin and Berlin-Brandenburg Center for Regenerative Therapies, Berlin
| | - Georg N. Duda
- Julius Wolff Institute, Charité – Universitätsmedizin Berlin and Berlin-Brandenburg Center for Regenerative Therapies, Berlin
| | - David J. Mooney
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge MA 02138, USA
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McDonald SJ, Dooley PC, McDonald AC, Schuijers JA, Ward AR, Grills BL. Transient expression of myofibroblast-like cells in rat rib fracture callus. Acta Orthop 2012; 83:93-8. [PMID: 22248170 PMCID: PMC3278664 DOI: 10.3109/17453674.2011.652891] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE We have previously shown that early fracture callus of rat rib has viscoelastic and contractile properties resembling those of smooth muscle. The cells responsible for this contractility have been hypothesized to be myofibroblast-like in nature. In soft-tissue healing, force generated by contraction of myofibroblasts promotes healing. Accordingly, we tried to identify myofibroblast-like cells in early fibrous callus. ANIMALS AND METHODS Calluses from rat rib fractures were removed 7, 14, and 21 days after fracture and unfractured ribs acted as controls. All tissues were analyzed using qPCR and immunohistochemistry. We analyzed expression of smooth muscle- and myofibroblast-associated genes and proteins including alpha smooth muscle actin (αSMA), non-muscle myosin, fibronectin extra domain A variant (EDA-fibronectin), OB-cadherin, connexin-43, basic calponin (h1CaP), and h-caldesmon. RESULTS In calluses at 7 days post-fracture, there were statistically significant increases in expression of αSMA mRNA (2.5 fold), h1CaP mRNA (2.1 fold), EDA-fibronectin mRNA (14 fold), and connexin-43 mRNA (1.8 fold) compared to unfractured ribs, and by 21 days post-fracture mRNA expression in calluses had decreased to levels approaching those in unfractured rib. Immunohistochemistry of 7 day fibrous callus localized calponin, EDA-fibronectin and co-immunolabeling of OB-cadherin and αSMA (thus confirming a myofibroblastic phenotype) within various cell populations. INTERPRETATION This study provides further evidence that early rat rib callus is not only smooth muscle-like in nature but also contains a notable population of cells that have a distinct myofibroblastic phenotype. The presence of these cells indicates that in vivo contraction of early callus is a mechanism that may occur in fractures so as to facilitate healing, as it does in soft tissue wound repair.
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Affiliation(s)
- Stuart J McDonald
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
| | - Philip C Dooley
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
| | - Aaron C McDonald
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
| | - Johannes A Schuijers
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
| | - Alex R Ward
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
| | - Brian L Grills
- Tissue and Cell Biology Group, Musculoskeletal Research Centre, La Trobe University, Victoria, Australia
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McDonald SJ, Dooley PC, McDonald AC, Djouma E, Schuijers JA, Ward AR, Grills BL. α(1) adrenergic receptor agonist, phenylephrine, actively contracts early rat rib fracture callus ex vivo. J Orthop Res 2011; 29:740-5. [PMID: 21437954 DOI: 10.1002/jor.21302] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 10/08/2010] [Indexed: 02/04/2023]
Abstract
Early, soft fracture callus that links fracture ends together is smooth muscle-like in nature. We aimed to determine if early fracture callus could be induced to contract and relax ex vivo by similar pathways to smooth muscle, that is, contraction via α(1) adrenergic receptor (α(1) AR) activation with phenylephrine (PE) and relaxation via β(2) adrenergic receptor (β(2) AR) stimulation with terbutaline. A sensitive force transducer quantified 7 day rat rib fracture callus responses in modified Krebs-Henseliet (KH) solutions. Unfractured ribs along with 7, 14, and 21 day fracture calluses were analyzed for both α(1) AR and β(2) AR gene expression using qPCR, whilst 7 day fracture callus was examined via immunohistochemistry for both α(1) AR and β(2) AR- immunoreactivity. In 7 day callus, PE (10(-6) M) significantly induced an increase in force that was greater than passive force generated in calcium-free KH (n = 8, mean 51% increase, 95% CI: 26-76%). PE-induced contractions in calluses were attenuated by the α(1) AR antagonist, prazosin (10(-6) M; n = 7, mean 5% increase, 95% CI: 2-11%). Terbutaline did not relax callus. Gene expression of α(1) ARs was constant throughout fracture healing; however, β(2) AR expression was down-regulated at 7 days compared to unfractured rib (p < 0.01). Furthermore, osteoprogenitor cells of early fibrous callus displayed considerable α(1) AR-like immunoreactivity but not β(2) AR-like immunoreactivity. Here, we demonstrate for the first time that early fracture callus can be pharmacologically induced to contract. We propose that increased concentrations of α(1) AR agonists such as noradrenaline may tonically contract callus in vivo to promote osteogenesis.
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Affiliation(s)
- Stuart J McDonald
- Musculoskeletal Research Centre, School of Human Biosciences, La Trobe University, Victoria 3086, Australia
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