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Ashinsky BG, Bonnevie ED, Mandalapu SA, Pickup S, Wang C, Han L, Mauck RL, Smith HE, Gullbrand SE. Intervertebral Disc Degeneration Is Associated With Aberrant Endplate Remodeling and Reduced Small Molecule Transport. J Bone Miner Res 2020; 35:1572-1581. [PMID: 32176817 PMCID: PMC8207249 DOI: 10.1002/jbmr.4009] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/18/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022]
Abstract
The intervertebral disc is the largest avascular structure in the body, and cells within the disc rely on diffusive transport via vasculature located within the vertebral endplate to receive nutrients, eliminate waste products, and maintain disc health. However, the mechanisms by which small molecule transport into the disc occurs in vivo and how these parameters change with disc degeneration remain understudied. Here, we utilize an in vivo rabbit puncture disc degeneration model to study these interactions and provide evidence that remodeling of the endplate adjacent to the disc occurs concomitant with degeneration. Our results identify significant increases in endplate bone volume fraction, increases in microscale stiffness of the soft tissue interfaces between the disc and vertebral bone, and reductions in endplate vascularity and small molecule transport into the disc as a function of degenerative state. A neural network model identified changes in diffusion into the disc as the most significant predictor of disc degeneration. These findings support the critical role of trans-endplate transport in disease progression and will improve patient selection to direct appropriate surgical intervention and inform new therapeutic approaches to improve disc health. © 2020 American Society for Bone and Mineral Research. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Beth G Ashinsky
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
- School of Biomedical Engineering Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Edward D Bonnevie
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Sai A Mandalapu
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Stephen Pickup
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Chao Wang
- School of Biomedical Engineering Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Lin Han
- School of Biomedical Engineering Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Robert L Mauck
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Harvey E Smith
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarah E Gullbrand
- Translational Musculoskeletal Research Center, Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
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Scheiber AL, Barton DK, Khoury BM, Marini JC, Swiderski DL, Caird MS, Kozloff KM. Sclerostin Antibody-Induced Changes in Bone Mass Are Site Specific in Developing Crania. J Bone Miner Res 2019; 34:2301-2310. [PMID: 31441963 PMCID: PMC7458133 DOI: 10.1002/jbmr.3858] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 07/24/2019] [Accepted: 08/14/2019] [Indexed: 01/01/2023]
Abstract
Sclerostin antibody (Scl-Ab) is an anabolic bone agent that has been shown to increase bone mass in clinical trials of adult diseases of low bone mass, such as osteoporosis and osteogenesis imperfecta (OI). Its use to decrease bone fragility in pediatric OI has shown efficacy in several growing mouse models, suggesting translational potential to pediatric disorders of low bone mass. However, the effects of pharmacologic inhibition of sclerostin during periods of rapid growth and development have not yet been described with respect to the cranium, where lifelong deficiency of functioning sclerostin leads to patterns of excessive bone growth, cranial compression, and facial palsy. In the present study, we undertook dimensional and volumetric measurements in the skulls of growing Brtl/+ OI mice treated with Scl-Ab to examine whether therapy-induced phenotypic changes were similar to those observed clinically in patients with sclerosteosis or Van Buchem disorder. Mice treated between 3 and 14 weeks of age with high doses of Scl-Ab show significant calvarial thickening capable of rescuing OI-induced deficiencies in skull thickness. Other changes in cranial morphology, such as lengths and distances between anatomic landmarks, intracranial volume, and suture interdigitation, showed minimal effects of Scl-Ab when compared with growth-induced differences over the treatment duration. Treatment-induced narrowing of foramina was limited to sites of vascular but not neural passage, suggesting patterns of local regulation. Together, these findings reveal a site specificity of Scl-Ab action in the calvaria with no measurable cranial nerve impingement or brainstem compression. This differentiation from the observed outcomes of lifelong sclerostin deficiency complements reports of Scl-Ab treatment efficacy at other skeletal sites with the prospect of minimal cranial secondary complications. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Amanda L Scheiber
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - David K Barton
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Basma M Khoury
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Joan C Marini
- Bone and Extracellular Matrix Branch, National Institute of Child Health and Human Disorders, NIH, Bethesda, MD, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
| | - Michelle S Caird
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Kenneth M Kozloff
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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