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Newman HR, Moore AC, Meadows KD, Hilliard RL, Boyes MS, Vresilovic EJ, Schaer TP, Elliott DM. Can axial loading restore in vivo disc geometry, opening pressure, and T2 relaxation time? JOR Spine 2024; 7:e1322. [PMID: 38666074 PMCID: PMC11045045 DOI: 10.1002/jsp2.1322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 02/25/2024] [Accepted: 02/29/2024] [Indexed: 04/28/2024] Open
Abstract
Background Cadaveric intervertebral discs are often studied for a variety of research questions, and outcomes are interpreted in the in vivo context. Unfortunately, the cadaveric disc does not inherently represent the LIVE condition, such that the disc structure (geometry), composition (T2 relaxation time), and mechanical function (opening pressure, OP) measured in the cadaver do not necessarily represent the in vivo disc. Methods We conducted serial evaluations in the Yucatan minipig of disc geometry, T2 relaxation time, and OP to quantify the changes that occur with progressive dissection and used axial loading to restore the in vivo condition. Results We found no difference in any parameter from LIVE to TORSO; thus, within 2 h of sacrifice, the TORSO disc can represent the LIVE condition. With serial dissection and sample preparation the disc height increased (SEGMENT height 18% higher than TORSO), OP decreased (POTTED was 67% lower than TORSO), and T2 time was unchanged. With axial loading, an imposed stress of 0.20-0.33 MPa returned the disc to in vivo, LIVE disc geometry and OP, although T2 time was decreased. There was a linear correlation between applied stress and OP, and this was conserved across multiple studies and species. Conclusion To restore the LIVE disc state in human studies or other animal models, we recommend measuring the OP/stress relationship and using this relationship to select the applied stress necessary to recover the in vivo condition.
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Affiliation(s)
- Harrah R. Newman
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - Axel C. Moore
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - Kyle D. Meadows
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - Rachel L. Hilliard
- Department of Clinical StudiesNew Bolton Center, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Madeline S. Boyes
- Department of Clinical StudiesNew Bolton Center, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | | | - Thomas P. Schaer
- Department of Clinical StudiesNew Bolton Center, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Dawn M. Elliott
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
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Fleps I, Newman HR, Elliott DM, Morgan EF. Geometric determinants of the mechanical behavior of image-based finite element models of the intervertebral disc. J Orthop Res 2024; 42:1343-1355. [PMID: 38245852 PMCID: PMC11055679 DOI: 10.1002/jor.25788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 12/17/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024]
Abstract
The intervertebral disc is an important structure for load transfer through the spine. Its injury and degeneration have been linked to pain and spinal fractures. Disc injury and spine fractures are associated with high stresses; however, these stresses cannot be measured, necessitating the use of finite element (FE) models. These models should include the disc's complex structure, as changes in disc geometry have been linked to altered mechanical behavior. However, image-based models using disc-specific structures have yet to be established. This study describes a multiphasic FE modeling approach for noninvasive estimates of subject-specific intervertebral disc mechanical behavior based on medical imaging. The models (n = 22) were used to study the influence of disc geometry on the predicted global mechanical response (moments and forces), internal local disc stresses, and tractions at the interface between the disc and the bone. Disc geometry was found to have a strong influence on the predicted moments and forces on the disc (R2 = 0.69-0.93), while assumptions regarding the side curvature (bulge) of the disc had only a minor effect. Strong variability in the predicted internal disc stresses and tractions was observed between the models (mean absolute differences of 5.1%-27.7%). Disc height had a systematic influence on the internal disc stresses and tractions at the disc-to-bone interface. The influence of disc geometry on mechanics highlights the importance of disc-specific modeling to estimate disc injury risk, loading on the adjacent vertebral bodies, and the mechanical environment present in disc tissues.
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Xi Z, Xie Y, Sun S, Wang N, Chen S, Kang X, Li J. Stepwise reduction of bony density in patients induces a higher risk of annular tears by deteriorating the local biomechanical environment. Spine J 2024; 24:831-841. [PMID: 38232914 DOI: 10.1016/j.spinee.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/15/2023] [Accepted: 12/27/2023] [Indexed: 01/19/2024]
Abstract
BACKGROUND CONTEXT The relationship between osteoporosis and intervertebral disc degeneration (IDD) remains unclear. Considering that annular tear is the primary phenotype of IDD in the lumbar spine, the deteriorating local biomechanical environment may be the main trigger for annular tears. PURPOSE To investigate whether poor bone mineral density (BMD) in the vertebral bodies may increase the risk of annular tears via the degradation of the local biomechanical environment. STUDY DESIGN This study was a retrospective investigation with relevant numerical mechanical simulations. PATIENT SAMPLE A total of 64 patients with low back pain (LBP) and the most severe IDD in the L4-L5 motion segment were enrolled. OUTCOME MEASURES Annulus integration status was assessed using diffusion tensor fibre tractography (DTT). Hounsfield unit (HU) values of adjacent vertebral bodies were employed to determine BMD. Numerical simulations were conducted to compute stress values in the annulus of models with different BMDs and body positions. METHODS The clinical data of the 64 patients with low back pain were collected retrospectively. The BMD of the vertebral bodies was measured using the HU values, and the annulus integration status was determined according to DTT. The data of the patients with and without annular tears were compared, and regression analysis was used to identify the independent risk factors for annular tears. Furthermore, finite element models of the L4-L5 motion segment were constructed and validated, followed by estimating the maximum stress on the post and postlateral interfaces between the superior and inferior bony endplates (BEPs) and the annulus. RESULTS Patients with lower HU values in their vertebral bodies had significantly higher incidence rates of annular tears, with decreased HU values being an independent risk factor for annular tears. Moreover, increased stress on the BEP-annulus interfaces was associated with a stepwise reduction of bony density (ie, elastic modulus) in the numerical models. CONCLUSIONS The stepwise reduction of bony density in patients results in a higher risk of annular tears by deteriorating the local biomechanical environment. Thus, osteoporosis should be considered to be a potential risk factor for IDD biomechanically.
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Affiliation(s)
- Zhipeng Xi
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 100th. Shizi Street , Nanjing, 210028, Jiangsu Province, P.R. China; Department of Orthopedics, Traditional Chinese Medicine Hospital of Ili Kazak Autonomous Prefecture, 2th. Jiankang Street, Yining, 835000, Xinjiang Uighur Autonomous Region, P.R. China
| | - Yimin Xie
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 100th. Shizi Street , Nanjing, 210028, Jiangsu Province, P.R. China
| | - Shenglu Sun
- Department of Imaging, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 100th. Shizi Street , Nanjing, 210028, Jiangsu Province, P.R. China
| | - Nan Wang
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 100th. Shizi Street , Nanjing, 210028, Jiangsu Province, P.R. China
| | - Shuang Chen
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 100th. Shizi Street , Nanjing, 210028, Jiangsu Province, P.R. China
| | - Xiong Kang
- Department of Orthopedics, Traditional Chinese Medicine Hospital of Ili Kazak Autonomous Prefecture, 2th. Jiankang Street, Yining, 835000, Xinjiang Uighur Autonomous Region, P.R. China
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, No.182, Chunhui Rd, Longmatan District, Luzhou, 646000, Sichuan Province, P.R. China.
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Buchweitz N, Sun Y, Cisewski Porto S, Kelley J, Niu Y, Wang S, Meng Z, Reitman C, Slate E, Yao H, Wu Y. Regional structure-function relationships of lumbar cartilage endplates. J Biomech 2024; 169:112131. [PMID: 38739987 PMCID: PMC11182561 DOI: 10.1016/j.jbiomech.2024.112131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/17/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024]
Abstract
Cartilage endplates (CEPs) act as protective mechanical barriers for intervertebral discs (IVDs), yet their heterogeneous structure-function relationships are poorly understood. This study addressed this gap by characterizing and correlating the regional biphasic mechanical properties and biochemical composition of human lumbar CEPs. Samples from central, lateral, anterior, and posterior portions of the disc (n = 8/region) were mechanically tested under confined compression to quantify swelling pressure, equilibrium aggregate modulus, and hydraulic permeability. These properties were correlated with CEP porosity and glycosaminoglycan (s-GAG) content, which were obtained by biochemical assays of the same specimens. Both swelling pressure (142.79 ± 85.89 kPa) and aggregate modulus (1864.10 ± 1240.99 kPa) were found to be regionally dependent (p = 0.0001 and p = 0.0067, respectively) in the CEP and trended lowest in the central location. No significant regional dependence was observed for CEP permeability (1.35 ± 0.97 * 10-16 m4/Ns). Porosity measurements correlated significantly with swelling pressure (r = -0.40, p = 0.0227), aggregate modulus (r = -0.49, p = 0.0046), and permeability (r = 0.36, p = 0.0421), and appeared to be the primary indicator of CEP biphasic mechanical properties. Second harmonic generation microscopy also revealed regional patterns of collagen fiber anchoring, with fibers inserting the CEP perpendicularly in the central region and at off-axial directions in peripheral regions. These results suggest that CEP tissue has regionally dependent mechanical properties which are likely due to the regional variation in porosity and matrix structure. This work advances our understanding of healthy baseline endplate biomechanics and lays a groundwork for further understanding the role of CEPs in IVD degeneration.
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Affiliation(s)
- Nathan Buchweitz
- Department of Bioengineering, Clemson University, Clemson, SC, USA.
| | - Yi Sun
- Department of Orthopaedics, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Sarah Cisewski Porto
- Department of Bioengineering, Clemson University, Clemson, SC, USA; School of Health Sciences, College of Charleston, Charleston, SC, USA.
| | - Joshua Kelley
- Department of Bioengineering, Clemson University, Clemson, SC, USA.
| | - Yipeng Niu
- College of Art and Science, New York University, New York City, NY, USA.
| | - Shangping Wang
- Department of Bioengineering, Clemson University, Clemson, SC, USA.
| | - Zhaoxu Meng
- Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.
| | - Charles Reitman
- Department of Orthopaedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, USA.
| | - Elizabeth Slate
- Department of Statistics, Florida State University, Tallahassee, FL, USA.
| | - Hai Yao
- Department of Bioengineering, Clemson University, Clemson, SC, USA; Department of Orthopaedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, USA.
| | - Yongren Wu
- Department of Bioengineering, Clemson University, Clemson, SC, USA; Department of Orthopaedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, USA.
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Xi Z, Xie Y, Sun S, Wang N, Chen S, Wang G, Li J. IVD fibrosis and disc collapse comprehensively aggravate vertebral body disuse osteoporosis and zygapophyseal joint osteoarthritis by posteriorly shifting the load transmission pattern. Comput Biol Med 2024; 170:108019. [PMID: 38325217 DOI: 10.1016/j.compbiomed.2024.108019] [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: 09/26/2023] [Revised: 12/26/2023] [Accepted: 01/22/2024] [Indexed: 02/09/2024]
Abstract
BACKGROUND Disuse is a typical phenotype of osteoporosis, but the underlying mechanism has yet to be identified in elderly patients. Disc collapse and intervertebral disc (IVD) fibrosis are two main pathological changes in IVD degeneration (IDD) progression, given that these changes affect load transmission patterns, which may lead to disuse osteoporosis of vertebral bodies and zygapophyseal joint (ZJ) osteoarthritis (ZJOA) biomechanically. METHODS Clinical data from 59 patients were collected retrospectively. Patient vertebral bony density, ZJOA grade, and disc collapse status were judged via CT. The IVD fibrosis grade was determined based on the FA measurements. Regression analyses identified potential independent risk factors for osteoporosis and ZJOA. L4-L5 numerical models with and without disc collapse and IVD fibrosis were constructed; stress distributions on the bony endplate (BEP) and zygapophyseal joint (ZJ) cartilages were computed in models with and without disc collapse and IVD fibrosis. RESULTS A significantly lower disc height ratio and significantly greater FA were recorded in patients with ZJOA. A significant correlation was observed between lower HU values and two parameters related to IDD progression. These factors were also proven to be independent risk factors for both osteoporosis and ZJOA. Correspondingly, compared to the intact model without IDD. Lower stress on vertebral bodies and greater stress on ZJOA can be simultaneously recorded in models of disc collapse and IVD fibrosis. CONCLUSIONS IVD fibrosis and disc collapse simultaneously aggravate vertebral body disuse osteoporosis and ZJOA by posteriorly shifting the load transmission pattern.
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Affiliation(s)
- Zhipeng Xi
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, PR China; Department of Orthopedics, Traditional Chinese Medicine Hospital of Ili Kazak Autonomous Prefecture, Yining, 835000, Xinjiang Uighur Autonomous Region, PR China
| | - Yimin Xie
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, PR China
| | - Shenglu Sun
- Department of Imaging, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, PR China
| | - Nan Wang
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, PR China
| | - Shuang Chen
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, PR China
| | - Guoyou Wang
- Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, NO.182, Chunhui Road, Longmatan District, Luzhou, Sichuan Province, 646000, PR China.
| | - Jingchi Li
- Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, NO.182, Chunhui Road, Longmatan District, Luzhou, Sichuan Province, 646000, PR China.
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Huang F, Huang G, Jia J, Lu S, Li J. Intraoperative capsule protection can reduce the potential risk of adjacent segment degeneration acceleration biomechanically: an in silico study. J Orthop Surg Res 2024; 19:143. [PMID: 38365801 PMCID: PMC10870541 DOI: 10.1186/s13018-024-04550-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/09/2024] [Indexed: 02/18/2024] Open
Abstract
BACKGROUND The capsule of the zygapophyseal joint plays an important role in motion segmental stability maintenance. Iatrogenic capsule injury is a common phenomenon in posterior approach lumbar interbody fusion operations, but whether this procedure will cause a higher risk of adjacent segment degeneration acceleration biomechanically has yet to be identified. METHODS Posterior lumbar interbody fusion (PLIF) with different grades of iatrogenic capsule injury was simulated in our calibrated and validated numerical model. By adjusting the cross-sectional area of the capsule, different grades of capsule injury were simulated. The stress distribution on the cranial motion segment was computed under different loading conditions to judge the potential risk of adjacent segment degeneration acceleration. RESULTS Compared to the PLIF model with an intact capsule, a stepwise increase in the stress value on the cranial motion segment can be observed with a step decrease in capsule cross-sectional areas. Moreover, compared to the difference between models with intact and slightly injured capsules, the difference in stress values was more evident between models with slight and severe iatrogenic capsule injury. CONCLUSION Intraoperative capsule protection can reduce the potential risk of adjacent segment degeneration acceleration biomechanically, and iatrogenic capsule damage on the cranial motion segment should be reduced to optimize patients' long-term prognosis.
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Affiliation(s)
- Fei Huang
- Department of Orthopedics, Meishan Hospital of Traditional Chinese Medicine, Meishan, China
| | - Gang Huang
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China
| | - Junpengli Jia
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China
| | - Shihao Lu
- Department of Orthopedics, Changzheng Hospital Affiliated to the Naval Medical University, Xiangyin Road, Shanghai, 200433, People's Republic of China.
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, No. 182, Chunhui Road, Longmatan District, Luzhou, 646000, Sichuan Province, People's Republic of China.
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China.
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Sun Z, Sun Y, Mi C. Comprehensive modeling of annulus fibrosus: From biphasic refined characterization to damage accumulation under viscous loading. Acta Biomater 2024; 174:228-244. [PMID: 38070844 DOI: 10.1016/j.actbio.2023.12.007] [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: 09/06/2023] [Revised: 11/26/2023] [Accepted: 12/05/2023] [Indexed: 12/17/2023]
Abstract
The annulus fibrosus (AF), a permeable, hydrated, and fiber-reinforced soft tissue, exhibits complex responses influenced by fluid pressure, osmotic pressure, and structural mechanics. Existing models struggle to comprehensively represent these intricate interactions and the heterogeneous solid responses within the AF. Additionally, the mechanisms driving differential damage accumulation between non-degenerative and degenerative intervertebral discs remain poorly understood. In this study, we introduce a biphasic-swelling damage model for the AF. We conceptually develop and rigorously validate this model through tissue-level tests employing various loading modes, consistently aligning model predictions with experimental data. Leveraging parametric geometric algorithms and custom Python scripts, we construct models simulating both non-degenerative and degenerative discs. Following calibration, we subject these models to viscous loading protocols. Our findings reveal the posterior AF's susceptibility to damage, contingent upon loading rate and water content. We elucidate the underlying mechanisms by examining the temporal evolution of fluid pressure, osmotic pressure, and the regionally dependent fiber network. This research presents a highly accurate model of the AF, providing valuable insights into disc damage. Future research endeavors should expand this model to incorporate ionic transport and diffusion, enabling a more profound exploration of intervertebral disc mechanobiology. This comprehensive model contributes to a better understanding of AF behavior and may inform therapeutic strategies for disc-related pathologies. STATEMENT OF SIGNIFICANCE: This research presents a comprehensive model of the annulus fibrosus (AF), a crucial component of the intervertebral disc that provides structural support and resists deformation. The study introduces a biphasic-swelling damage model for the AF and validates it through tissue-level tests. The model accounts for fluid pressure, osmotic pressure, and matrix mechanics, providing a more accurate representation of the AF's behavior. The study also investigates the differential damage accumulation between non-degenerative and degenerative discs, shedding light on the mechanisms driving disc degeneration. The findings have significant implications for medical treatments and interventions, as they highlight the posterior AF's susceptibility to damage. This research is of great interest to readers interested in biomechanics, tissue engineering, and medical treatments for disc degeneration.
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Affiliation(s)
- Zhongwei Sun
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Yueli Sun
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, Shanghai 200032, China
| | - Changwen Mi
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China.
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Kuchynsky K, Stevens P, Hite A, Xie W, Diop K, Tang S, Pietrzak M, Khan S, Walter B, Purmessur D. Transcriptional profiling of human cartilage endplate cells identifies novel genes and cell clusters underlying degenerated and non-degenerated phenotypes. Arthritis Res Ther 2024; 26:12. [PMID: 38173036 PMCID: PMC10763221 DOI: 10.1186/s13075-023-03220-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/22/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Low back pain is a leading cause of disability worldwide and is frequently attributed to intervertebral disc (IVD) degeneration. Though the contributions of the adjacent cartilage endplates (CEP) to IVD degeneration are well documented, the phenotype and functions of the resident CEP cells are critically understudied. To better characterize CEP cell phenotype and possible mechanisms of CEP degeneration, bulk and single-cell RNA sequencing of non-degenerated and degenerated CEP cells were performed. METHODS Human lumbar CEP cells from degenerated (Thompson grade ≥ 4) and non-degenerated (Thompson grade ≤ 2) discs were expanded for bulk (N=4 non-degenerated, N=4 degenerated) and single-cell (N=1 non-degenerated, N=1 degenerated) RNA sequencing. Genes identified from bulk RNA sequencing were categorized by function and their expression in non-degenerated and degenerated CEP cells were compared. A PubMed literature review was also performed to determine which genes were previously identified and studied in the CEP, IVD, and other cartilaginous tissues. For single-cell RNA sequencing, different cell clusters were resolved using unsupervised clustering and functional annotation. Differential gene expression analysis and Gene Ontology, respectively, were used to compare gene expression and functional enrichment between cell clusters, as well as between non-degenerated and degenerated CEP samples. RESULTS Bulk RNA sequencing revealed 38 genes were significantly upregulated and 15 genes were significantly downregulated in degenerated CEP cells relative to non-degenerated cells (|fold change| ≥ 1.5). Of these, only 2 genes were previously studied in CEP cells, and 31 were previously studied in the IVD and other cartilaginous tissues. Single-cell RNA sequencing revealed 11 unique cell clusters, including multiple chondrocyte and progenitor subpopulations with distinct gene expression and functional profiles. Analysis of genes in the bulk RNA sequencing dataset showed that progenitor cell clusters from both samples were enriched in "non-degenerated" genes but not "degenerated" genes. For both bulk- and single-cell analyses, gene expression and pathway enrichment analyses highlighted several pathways that may regulate CEP degeneration, including transcriptional regulation, translational regulation, intracellular transport, and mitochondrial dysfunction. CONCLUSIONS This thorough analysis using RNA sequencing methods highlighted numerous differences between non-degenerated and degenerated CEP cells, the phenotypic heterogeneity of CEP cells, and several pathways of interest that may be relevant in CEP degeneration.
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Affiliation(s)
- Kyle Kuchynsky
- Department of Biomedical Engineering, The Ohio State University, 3016 Fontana Laboratories, 140 W. 19th Ave, Columbus, OH, 43210, USA
| | - Patrick Stevens
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - Amy Hite
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
| | - William Xie
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Khady Diop
- Department of Biomedical Engineering, The Ohio State University, 3016 Fontana Laboratories, 140 W. 19th Ave, Columbus, OH, 43210, USA
| | - Shirley Tang
- Department of Biomedical Engineering, The Ohio State University, 3016 Fontana Laboratories, 140 W. 19th Ave, Columbus, OH, 43210, USA
| | - Maciej Pietrzak
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA
- The James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Safdar Khan
- Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Benjamin Walter
- Department of Biomedical Engineering, The Ohio State University, 3016 Fontana Laboratories, 140 W. 19th Ave, Columbus, OH, 43210, USA
| | - Devina Purmessur
- Department of Biomedical Engineering, The Ohio State University, 3016 Fontana Laboratories, 140 W. 19th Ave, Columbus, OH, 43210, USA.
- Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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Xi Z, Xie Y, Chen S, Sun S, Zhang X, Yang J, Li J. The cranial vertebral body suffers a higher risk of adjacent vertebral fracture due to the poor biomechanical environment in patients with percutaneous vertebralplasty. Spine J 2023; 23:1764-1777. [PMID: 37611873 DOI: 10.1016/j.spinee.2023.08.003] [Citation(s) in RCA: 3] [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: 05/16/2023] [Revised: 07/08/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023]
Abstract
BACKGROUND CONTEXT Adjacent vertebral fracture (AVF), a frequent complication of PVP, is influenced by factors such as osteoporosis progression, increased intervertebral cement leakage (ICL), and biomechanical deterioration. Notably, the risk of AVF is notably elevated in the cranial vertebral body compared with the caudal counterpart. Despite this knowledge, the underlying pathological mechanism remains elusive. PURPOSE This study delves into the role of biomechanical deterioration as a pivotal factor in the heightened risk of AVF in the cranial vertebral body following PVP. By isolating this variable, we aim to unravel its prominence relative to other potential risk factors. STUDY DESIGN A retrospective study and corresponding numerical mechanical simulations. PATIENT SAMPLE Clinical data from 101 patients treated by PVP were reviewed in this study. OUTCOME MEASURES Clinical assessments involved measuring Hounsfield unit (HU) values of adjacent vertebral bodies as a representation of patients' bone mineral density (BMD). Additionally, the rates of ICL were compared among these patients. Numerical simulations were conducted to compute stress values in the cranial and caudal vertebral bodies under various body positions. METHODS In a retrospective analysis of PVP patients spanning July 2016 to August 2019, we scrutinized the HU values of adjacent vertebral bodies to discern disparities in BMD between cranial and caudal regions. Additionally, we compared ICL rates on both cranial and caudal sides. To augment our investigation, well-validated numerical models simulated the PVP procedure, enabling the computation of maximum stress values in cranial and caudal vertebral bodies across varying body positions. RESULTS The incidence rate of cranial AVF was significantly higher than the caudal side. No notable distinctions in HU values or ICL rates were observed between the cranial and caudal sides. The incidence of AVF showed no significant elevation in patients with ICL in either region. However, numerical simulations unveiled heightened stress values in the cranial vertebral body. CONCLUSIONS In patients postPVP, the cranial vertebral body faces a heightened risk of AVF, primarily attributed to biomechanical deterioration rather than lower BMD or an elevated ICL rate.
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Affiliation(s)
- Zhipeng Xi
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, P.R. China
| | - Yimin Xie
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, P.R. China
| | - Shuang Chen
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, P.R. China
| | - Shenglu Sun
- Department of Imaging, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine for Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, P.R. China
| | - Xiaoyu Zhang
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, Jiangsu Province, P.R. China
| | - Jiexiang Yang
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, No.182, Chunhui Rd, Longmatan District, Luzhou, Sichuan Province, 646000, P.R. China
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, No.182, Chunhui Rd, Longmatan District, Luzhou, Sichuan Province, 646000, P.R. China.
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Crump KB, Alminnawi A, Bermudez‐Lekerika P, Compte R, Gualdi F, McSweeney T, Muñoz‐Moya E, Nüesch A, Geris L, Dudli S, Karppinen J, Noailly J, Le Maitre C, Gantenbein B. Cartilaginous endplates: A comprehensive review on a neglected structure in intervertebral disc research. JOR Spine 2023; 6:e1294. [PMID: 38156054 PMCID: PMC10751983 DOI: 10.1002/jsp2.1294] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 09/15/2023] [Accepted: 09/26/2023] [Indexed: 12/30/2023] Open
Abstract
The cartilaginous endplates (CEP) are key components of the intervertebral disc (IVD) necessary for sustaining the nutrition of the disc while distributing mechanical loads and preventing the disc from bulging into the adjacent vertebral body. The size, shape, and composition of the CEP are essential in maintaining its function, and degeneration of the CEP is considered a contributor to early IVD degeneration. In addition, the CEP is implicated in Modic changes, which are often associated with low back pain. This review aims to tackle the current knowledge of the CEP regarding its structure, composition, permeability, and mechanical role in a healthy disc, how they change with degeneration, and how they connect to IVD degeneration and low back pain. Additionally, the authors suggest a standardized naming convention regarding the CEP and bony endplate and suggest avoiding the term vertebral endplate. Currently, there is limited data on the CEP itself as reported data is often a combination of CEP and bony endplate, or the CEP is considered as articular cartilage. However, it is clear the CEP is a unique tissue type that differs from articular cartilage, bony endplate, and other IVD tissues. Thus, future research should investigate the CEP separately to fully understand its role in healthy and degenerated IVDs. Further, most IVD regeneration therapies in development failed to address, or even considered the CEP, despite its key role in nutrition and mechanical stability within the IVD. Thus, the CEP should be considered and potentially targeted for future sustainable treatments.
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Affiliation(s)
- Katherine B. Crump
- Tissue Engineering for Orthopaedics & Mechanobiology, Bone & Joint Program, Department for BioMedical Research (DBMR), Medical FacultyUniversity of BernBernSwitzerland
- Department of Orthopaedic Surgery and Traumatology, InselspitalBern University Hospital, Medical Faculty, University of BernBernSwitzerland
- Graduate School for Cellular and Biomedical Sciences (GCB)University of BernBernSwitzerland
| | - Ahmad Alminnawi
- GIGA In Silico MedicineUniversity of LiègeLiègeBelgium
- Skeletal Biology and Engineering Research Center, KU LeuvenLeuvenBelgium
- Biomechanics Research Unit, KU LeuvenLeuvenBelgium
| | - Paola Bermudez‐Lekerika
- Tissue Engineering for Orthopaedics & Mechanobiology, Bone & Joint Program, Department for BioMedical Research (DBMR), Medical FacultyUniversity of BernBernSwitzerland
- Department of Orthopaedic Surgery and Traumatology, InselspitalBern University Hospital, Medical Faculty, University of BernBernSwitzerland
- Graduate School for Cellular and Biomedical Sciences (GCB)University of BernBernSwitzerland
| | - Roger Compte
- Twin Research & Genetic EpidemiologySt. Thomas' Hospital, King's College LondonLondonUK
| | - Francesco Gualdi
- Institut Hospital del Mar d'Investigacions Mèdiques (IMIM)BarcelonaSpain
| | - Terence McSweeney
- Research Unit of Health Sciences and TechnologyUniversity of OuluOuluFinland
| | - Estefano Muñoz‐Moya
- BCN MedTech, Department of Information and Communication TechnologiesUniversitat Pompeu FabraBarcelonaSpain
| | - Andrea Nüesch
- Division of Clinical Medicine, School of Medicine and Population HealthUniversity of SheffieldSheffieldUK
| | - Liesbet Geris
- GIGA In Silico MedicineUniversity of LiègeLiègeBelgium
- Skeletal Biology and Engineering Research Center, KU LeuvenLeuvenBelgium
- Biomechanics Research Unit, KU LeuvenLeuvenBelgium
| | - Stefan Dudli
- Center of Experimental RheumatologyDepartment of Rheumatology, University Hospital Zurich, University of ZurichZurichSwitzerland
- Department of Physical Medicine and RheumatologyBalgrist University Hospital, Balgrist Campus, University of ZurichZurichSwitzerland
| | - Jaro Karppinen
- Research Unit of Health Sciences and TechnologyUniversity of OuluOuluFinland
- Finnish Institute of Occupational HealthOuluFinland
- Rehabilitation Services of South Karelia Social and Health Care DistrictLappeenrantaFinland
| | - Jérôme Noailly
- BCN MedTech, Department of Information and Communication TechnologiesUniversitat Pompeu FabraBarcelonaSpain
| | - Christine Le Maitre
- Division of Clinical Medicine, School of Medicine and Population HealthUniversity of SheffieldSheffieldUK
| | - Benjamin Gantenbein
- Tissue Engineering for Orthopaedics & Mechanobiology, Bone & Joint Program, Department for BioMedical Research (DBMR), Medical FacultyUniversity of BernBernSwitzerland
- Department of Orthopaedic Surgery and Traumatology, InselspitalBern University Hospital, Medical Faculty, University of BernBernSwitzerland
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Ren P, Chen P, Reeves RA, Buchweitz N, Niu H, Gong H, Mercuri J, Reitman CA, Yao H, Wu Y. Diffusivity of Human Cartilage Endplates in Healthy and Degenerated Intervertebral Disks. J Biomech Eng 2023; 145:071006. [PMID: 36752723 PMCID: PMC10159583 DOI: 10.1115/1.4056871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/29/2023] [Accepted: 02/05/2023] [Indexed: 02/09/2023]
Abstract
The cartilage endplates (CEPs) on the superior and inferior surfaces of the intervertebral disk (IVD), are the primary nutrient transport pathways between the disk and the vertebral body. Passive diffusion is responsible for transporting small nutrient and metabolite molecules through the avascular CEPs. The baseline solute diffusivities in healthy CEPs have been previously studied, however alterations in CEP diffusion associated with IVD degeneration remain unclear. This study aimed to quantitatively compare the solute diffusion in healthy and degenerated human CEPs using a fluorescence recovery after photobleaching (FRAP) approach. Seven healthy CEPs and 22 degenerated CEPs were collected from five fresh-frozen human cadaveric spines and 17 patients undergoing spine fusion surgery, respectively. The sodium fluorescein diffusivities in CEP radial and vertical directions were measured using the FRAP method. The CEP calcification level was evaluated by measuring the average X-ray attenuation. No difference was found in solute diffusivities between radial and axial directions in healthy and degenerated CEPs. Compared to healthy CEPs, the average solute diffusivity was 44% lower in degenerated CEPs (Healthy: 29.07 μm2/s (CI: 23.96-33.62 μm2/s); degenerated: 16.32 μm2/s (CI: 13.84-18.84 μm2/s), p < 0.001). The average solute diffusivity had an inverse relationship with the degree of CEP calcification as determined by the normalized X-ray attenuation values (ß = -22.19, R2 = 0.633; p < 0.001). This study suggests that solute diffusion through the disk and vertebral body interface is significantly hindered by CEP calcification, providing clues to help further understand the mechanism of IVD degeneration.
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Affiliation(s)
- Pengling Ren
- Department of Bioengineering, Clemson University, Clemson, SC 29425; Department of Orthopaedics and Physical Medicine, Medical University of South Carolina (MUSC), Charleston, SC 29425; Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100052, China; Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Peng Chen
- Department of Bioengineering, Clemson University, Clemson, SC 29425
| | - Russell A. Reeves
- Department of Radiology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107
| | - Nathan Buchweitz
- Department of Bioengineering, Clemson University, Clemson, SC 29425
| | - Haijun Niu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - He Gong
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Jeremy Mercuri
- Department of Bioengineering, Clemson University, Clemson, SC 29425
| | - Charles A. Reitman
- Department of Orthopaedics and Physical Medicine, Medical University of South Carolina (MUSC), Charleston, SC 29425
| | - Hai Yao
- Department of Bioengineering, Clemson University, Clemson, SC 29425; Department of Orthopaedics and Physical Medicine, Medical University of South Carolina (MUSC), Charleston, SC 29425
| | - Yongren Wu
- Department of Bioengineering, Clemson University, 68 President Street, MSC501, Clemson, SC 29425; Department of Orthopaedics and Physical Medicine, Medical University of South Carolina (MUSC), Charleston, SC 29425
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12
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Sun Z, Sun Y, Lu T, Li J, Mi C. A swelling-based biphasic analysis on the quasi-static biomechanical behaviors of healthy and degenerative intervertebral discs. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 235:107513. [PMID: 37030175 DOI: 10.1016/j.cmpb.2023.107513] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/18/2023] [Accepted: 03/26/2023] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND OBJECTIVE The degeneration of intervertebral discs is significantly dependent of the changes in tissue composition ratio and tissue structure. Up to the present, the effects of degeneration on the quasi-static biomechanical responses of discs have not been well understood. The goal of this study is to quantitatively analyze the quasi-static responses of healthy and degenerative discs. METHODS Four biphasic swelling-based finite element models are developed and quantitatively validated. Four quasi-static test protocols, including the free-swelling, slow-ramp, creep and stress-relaxation, are implemented. The double Voigt and double Maxwell models are further used to extract the immediate (or residual), short-term and long-term responses of these tests. RESULTS Simulation results show that both the swelling-induced pressure in the nucleus pulposus and the initial modulus decrease with degeneration. In the free-swelling test of discs possessing healthy cartilage endplates, simulation results show that over 80% of the total strain is contributed by the short-term response. The long-term response is dominant for discs with degenerated permeability in cartilage endplates. For the creep test, over 50% of the deformation is contributed by the long-term response. In the stress-relaxation test, the long-term stress contribution occupies approximately 31% of total response and is independent of degeneration. Both the residual and short-term responses vary monotonically with degeneration. In addition, both the glycosaminoglycan content and permeability affect the engineering equilibrium time constants of the rheologic models, in which the determining factor is the permeability. CONCLUSIONS The content of glycosaminoglycan in intervertebral soft tissues and the permeability of cartilage endplates are two critical factors that affect the fluid-dependent viscoelastic responses of intervertebral discs. The component proportions of the fluid-dependent viscoelastic responses depend also strongly on test protocols. In the slow-ramp test, the glycosaminoglycan content is responsible for the changes of the initial modulus. Since existing computational models simulate disc degenerations only by altering disc height, boundary conditions and material stiffness, the current work highlights the significance of biochemical composition and cartilage endplates permeability in the biomechanical behaviors of degenerated discs.
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Affiliation(s)
- Zhongwei Sun
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, 2 Sipailou Street, Nanjing, 210096, Jiangsu, China
| | - Yueli Sun
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, Shanghai, China
| | - Teng Lu
- Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, 30 Huangcheng West Road, Xi'an, 710004, Shaanxi, China
| | - Jialiang Li
- Department of Orthopedics, Second Affiliated Hospital of Xi'an Jiaotong University, 30 Huangcheng West Road, Xi'an, 710004, Shaanxi, China
| | - Changwen Mi
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, 2 Sipailou Street, Nanjing, 210096, Jiangsu, China.
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13
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Cai P, Xi Z, Deng C, Li J, Zhang X, Zhou Y. Fixation-induced surgical segment's high stiffness and the damage of posterior structures together trigger a higher risk of adjacent segment disease in patients with lumbar interbody fusion operations. J Orthop Surg Res 2023; 18:371. [PMID: 37208705 DOI: 10.1186/s13018-023-03838-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/06/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND Adjacent segment disease (ASD) is a commonly reported complication after lumbar interbody fusion (LIF); changes in the mechanical environment play an essential role in the generation of ASD. Traditionally, fixation-induced high stiffness in the surgical segment was the main reason for ASD. However, with more attention paid to the biomechanical significance of posterior bony and soft structures, surgeons hypothesize that this factor may also play an important role in ASD. METHODS Oblique and posterior LIF operations have been simulated in this study. The stand-alone OLIF and OLIF fixed by bilateral pedicle screw (BPS) system have been simulated. The spinal process (the attachment point of cranial ligamentum complex) was excised in the PLIF model; the BPS system has also been used in the PLIF model. Stress values related to ASD have been computed under physiological body positions, including flexion, extension, bending, and axial rotations. RESULTS Compared to the stand-alone OLIF model, the OLIF model with BPS fixation suffers higher stress values under extension body position. However, there are no apparent differences under other loading conditions. Moreover, significant increases in stress values can be recorded in flexion and extension loading conditions in the PLIF model with posterior structures damage. CONCLUSIONS Fixation-induced surgical segment's high stiffness and the damage of posterior soft tissues together trigger a higher risk of ASD in patients with LIF operations. Optimizing BPS fixation methods and pedicle screw designs and reducing the range of posterior structures excision may be an effective method to reduce the risk of ASD.
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Affiliation(s)
- Ping Cai
- Department of Orthopedics, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, Jiangsu, People's Republic of China
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Zhieng Xi
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Chao Deng
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Jingchi Li
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Xiaoyu Zhang
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Yingguang Zhou
- Department of Orthopedics, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, Jiangsu, People's Republic of China.
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14
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Kong L, Xie YS, Ma XD, Huang Y, Shang XF. Mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension. J Orthop Surg Res 2023; 18:229. [PMID: 36944987 PMCID: PMC10031924 DOI: 10.1186/s13018-023-03704-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/13/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND This study aimed to investigate the potential mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension (ICMT). METHODS According to the Pfirrmann grade evaluation classification, 30 human endplate cartilage tissues were divided into the lumbar vertebra fracture (LVF) group and lumbar disc herniation (LDH) group. Then, quantitative reverse transcription polymerase chain reaction, western blot, flow cytometry, hematoxylin-eosin staining, and senescence-associated β-galactosidase staining were performed. The difference in extracellular matrix expression between LVF and LDH endplate cartilage was detected. Second, the effect of ICMT on endplate chondrocytes degeneration was observed. Finally, the key regulatory role of YAP1 in ICMT-induced endplate cartilage degeneration was further verified. RESULTS In degraded human endplate cartilage and tension-induced degraded endplate chondrocytes, the expression of YAP1, COL-2A, and Sox9 was decreased. Conversely, the expression of p53 and p21 was increased. By regulating YAP1 in vivo and in vitro, we can achieve alleviation of ICMT-induced senescence of endplate chondrocytes and effective treatment of disc degeneration. CONCLUSIONS ICMT could induce senescence and degeneration of endplate chondrocytes, and ICMT-induced senescence and degeneration of endplate chondrocytes could be alleviated by regulating YAP1 expression.
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Affiliation(s)
- Lei Kong
- Division of Life Science and Medicine, Department of Orthopedic, The First Affiliated Hospital of USTC, University of Science and Technology of China, HeFei, 230001, Anhui, China
| | - Yong-Sheng Xie
- Division of Life Science and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, HeFei, 230001, Anhui, China
| | - Xu-Dong Ma
- BengBu Medical College, Bengbu, 233030, Anhui, China
| | - Yan Huang
- Division of Life Science and Medicine, Department of Orthopedic, The First Affiliated Hospital of USTC, University of Science and Technology of China, HeFei, 230001, Anhui, China
| | - Xi-Fu Shang
- Division of Life Science and Medicine, Department of Orthopedic, The First Affiliated Hospital of USTC, University of Science and Technology of China, HeFei, 230001, Anhui, China.
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15
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Huang C, Liu Z, Wei Z, Fang Z, Xi Z, Cai P, Li J. Will the adjustment of insertional pedicle screw positions affect the risk of adjacent segment diseases biomechanically? An in-silico study. Front Surg 2023; 9:1004642. [PMID: 36713678 PMCID: PMC9877423 DOI: 10.3389/fsurg.2022.1004642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/20/2022] [Indexed: 01/13/2023] Open
Abstract
Background The fixation-induced biomechanical deterioration will increase the risk of adjacent segment diseases (ASD) after lumbar interbody fusion with Bilateral pedicle screw (BPS) fixation. The accurate adjustment of insertional pedicle screw positions is possible, and published studies have reported its mechanical effects. However, no studies clarified that adjusting insertional screw positions would affect the postoperative biomechanical environment and the risk of ASD. The objective of this study was to identify this issue and provide theoretical references for the optimization of insertional pedicle screw position selections. Methods The oblique lumbar interbody fusion fixed by BPS with different insertional positions has been simulated in the L4-L5 segment of our previously constructed and validated lumbosacral model. Biomechanical indicators related to ASD have been computed and recorded under flexion, extension, bending, and axial rotation loading conditions. Results The change of screw insertional positions has more apparent biomechanical effects on the cranial than the caudal segment. Positive collections can be observed between the reduction of the fixation length and the alleviation of motility compensation and stress concentration on facet cartilages. By contrast, no pronounced tendency of stress distribution on the intervertebral discs can be observed with the change of screw positions. Conclusions Reducing the fixation stiffness by adjusting the insertional screw positions could alleviate the biomechanical deterioration and be an effective method to reduce the risk of ASD caused by BPS.
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Affiliation(s)
- Chenyi Huang
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zongchao Liu
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zhangchao Wei
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zhongxin Fang
- Fluid and Power Machinery Key Laboratory of Ministry of Education, Xihua University, Chengdu, China
| | - Zhipeng Xi
- Department of Spine Surgery, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Ping Cai
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China,Correspondence: Jingchi Li Ping Cai
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China,Correspondence: Jingchi Li Ping Cai
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16
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Meadows KD, Peloquin JM, Newman HR, Cauchy PJK, Vresilovic EJ, Elliott DM. MRI
‐based measurement of in vivo disc mechanics in a young population due to flexion, extension, and diurnal loading. JOR Spine 2023; 6:e1243. [PMID: 36994458 PMCID: PMC10041375 DOI: 10.1002/jsp2.1243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/14/2022] [Accepted: 12/21/2022] [Indexed: 01/12/2023] Open
Abstract
Background Intervertebral disc degeneration is often implicated in low back pain; however, discs with structural degeneration often do not cause pain. It may be that disc mechanics can provide better diagnosis and identification of the pain source. In cadaveric testing, the degenerated disc has altered mechanics, but in vivo, disc mechanics remain unknown. To measure in vivo disc mechanics, noninvasive methods must be developed to apply and measure physiological deformations. Aim Thus, this study aimed to develop methods to measure disc mechanical function via noninvasive MRI during flexion and extension and after diurnal loading in a young population. This data will serve as baseline disc mechanics to later compare across ages and in patients. Materials & Methods To accomplish this, subjects were imaged in the morning in a reference supine position, in flexion, in extension, and at the end of the day in a supine position. Disc deformations and vertebral motions were used to quantify disc axial strain, changes in wedge angle, and anterior-posterior (A-P) shear displacement. T2 weighted MRI was also used to evaluate disc degeneration via Pfirrmann grading and T2 time. All measures were then tested for effect of sex and disc level. Results We found that flexion and extension caused level-dependent strains in the anterior and posterior of the disc, changes in wedge angle, and A-P shear displacements. Flexion had higher magnitude changes overall. Diurnal loading did not cause level-dependent strains but did cause small level-dependent changes in wedge angle and A-P shear displacements. Discussion Correlations between disc degeneration and mechanics were largest in flexion, likely due to the smaller contribution of the facet joints in this condition. Conclusion In summary, this study established methods to measure in vivo disc mechanical function via noninvasive MRI and established a baseline in a young population that may be compared to older subjects and clinical disorders in the future.
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Affiliation(s)
- Kyle D. Meadows
- Department of Biomedical Engineering University of Delaware Newark Delaware USA
| | - John M. Peloquin
- Department of Biomedical Engineering University of Delaware Newark Delaware USA
| | - Harrah R. Newman
- Department of Biomedical Engineering University of Delaware Newark Delaware USA
| | - Peter J. K. Cauchy
- Department of Biomedical Engineering University of Delaware Newark Delaware USA
| | | | - Dawn M. Elliott
- Department of Biomedical Engineering University of Delaware Newark Delaware USA
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Habib M, Hussien S, Jeon O, Lotz JC, Wu PIK, Alsberg E, Fields AJ. Intradiscal treatment of the cartilage endplate for improving solute transport and disc nutrition. Front Bioeng Biotechnol 2023; 11:1111356. [PMID: 36923455 PMCID: PMC10008947 DOI: 10.3389/fbioe.2023.1111356] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/09/2023] [Indexed: 03/03/2023] Open
Abstract
Poor nutrient transport through the cartilage endplate (CEP) is a key factor in the etiology of intervertebral disc degeneration and may hinder the efficacy of biologic strategies for disc regeneration. Yet, there are currently no treatments for improving nutrient transport through the CEP. In this study we tested whether intradiscal delivery of a matrix-modifying enzyme to the CEP improves solute transport into whole human and bovine discs. Ten human lumbar motion segments harvested from five fresh cadaveric spines (38-66 years old) and nine bovine coccygeal motion segments harvested from three adult steers were treated intradiscally either with collagenase enzyme or control buffer that was loaded in alginate carrier. Motion segments were then incubated for 18 h at 37 °C, the bony endplates removed, and the isolated discs were compressed under static (0.2 MPa) and cyclic (0.4-0.8 MPa, 0.2 Hz) loads while submerged in fluorescein tracer solution (376 Da; 0.1 mg/ml). Fluorescein concentrations from site-matched nucleus pulposus (NP) samples were compared between discs. CEP samples from each disc were digested and assayed for sulfated glycosaminoglycan (sGAG) and collagen contents. Results showed that enzymatic treatment of the CEP dramatically enhanced small solute transport into the disc. Discs with enzyme-treated CEPs had up to 10.8-fold (human) and 14.0-fold (bovine) higher fluorescein concentration in the NP compared to site-matched locations in discs with buffer-treated CEPs (p < 0.0001). Increases in solute transport were consistent with the effects of enzymatic treatment on CEP composition, which included reductions in sGAG content of 33.5% (human) and 40% (bovine). Whole disc biomechanical behavior-namely, creep strain and disc modulus-was similar between discs with enzyme- and buffer-treated CEPs. Taken together, these findings demonstrate the potential for matrix modification of the CEP to improve the transport of small solutes into whole intact discs.
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Affiliation(s)
- Mohamed Habib
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States.,Department of Mechanical Engineering, Al Azhar University, Cairo, Egypt
| | - Shayan Hussien
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Oju Jeon
- Department of Biomedical Engineering, University of Illinois, Chicago, IL, United States
| | - Jeffrey C Lotz
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Peter I-Kung Wu
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Eben Alsberg
- Department of Biomedical Engineering, University of Illinois, Chicago, IL, United States
| | - Aaron J Fields
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States
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18
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Parisien A, Wai EK, ElSayed MS, Frei H. Subsidence of Spinal Fusion Cages: A Systematic Review. Int J Spine Surg 2022; 16:1103-1118. [PMID: 36289005 PMCID: PMC9807049 DOI: 10.14444/8363] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Although many research studies investigating subsidence of intervertebral fusion cages have been published, to our knowledge, no study has comprehensively compared cage subsidence among all lumbar intervertebral fusion (LIF) techniques. This study aimed to review the literature reporting evidence of cage subsidence linked to LIF. The amount of subsidence was compared and associated with the procedures and corresponding implants used, and the effect of cage subsidence on clinical outcomes was investigated. METHODS For this systematic review, the MEDLINE and PubMed databases were used to identify relevant studies. Search terms included lumbar, lumbar vertebrae, lumbar spine, cage, spinal fusion, prosthesis, prosthesis implantation, implantation, implants, interbody, spacer, and subsidence. Studies included in this review were those having more than 10 patients and reporting the amount of subsidence observed using computed tomography or x-ray imaging after surgery and at follow-up visits after a minimum of 6 weeks postsurgery. Data and scale definitions related to subsidence were extracted from articles for comparison of subsidence prevalence between the 5 LIF surgical procedures. RESULTS Forty articles were identified for inclusion. The review included data from 390 anterior lumbar intervertebral fusions (ALIFs), 2130 lateral lumbar intervertebral fusions (LLIFs), 560 posterior lumbar intervertebral fusions (PLIFs), 245 oblique lumbar intervertebral fusions (OLIFs), and 1634 transverse lumbar intervertebral fusions (TLIFs) for a total of 4959 patients who underwent LIF surgery. The minimum and maximum percentages of the number of patients having subsidence for each procedure in the included studies were as follows: ALIF stand-alone, 6% and 23.1%; LLIF stand-alone, 8.7% and 39.6%; LLIF with posterior fixation, 3.3% and 20.7%; OLIF with posterior fixation, 4.4% and 36.9%; PLIF with posterior fixation, 7.4% and 31.8%; and TLIF, 0.0% and 51.2%. CONCLUSIONS The number of patients experiencing subsidence varied between studies within each fusion procedure. Our findings indicate that all 5 surgical methods are at risk of subsidence. Overall, ALIF without posterior fixation resulted in the lowest reported subsidence occurrence among the 5 surgical approaches. There is conflicting evidence on the association between subsidence and negative clinical outcomes. CLINICAL RELEVANCE This review defines and compares subsidence incidence between all LIF procedures and investigates the risk of symptomatic clinical outcomes. LEVEL OF EVIDENCE: 4
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Affiliation(s)
- Ariane Parisien
- Mechanical and Aerospace Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Eugene K. Wai
- Orthopeadic Surgery, University of Ottawa, Ottawa, Ontario, Canada
| | - Mostafa S.A. ElSayed
- Mechanical and Aerospace Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Hanspeter Frei
- Mechanical and Aerospace Engineering, Carleton University, Ottawa, Ontario, Canada, Hanspeter Frei, Mechanical and Aerospace Engineering, 3135 Mackenzie Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada;
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Li JC, Yang ZQ, Xie TH, Song ZT, Song YM, Zeng JC. Deterioration of the fixation segment’s stress distribution and the strength reduction of screw holding position together cause screw loosening in ALSR fixed OLIF patients with poor BMD. Front Bioeng Biotechnol 2022; 10:922848. [PMID: 36110315 PMCID: PMC9468878 DOI: 10.3389/fbioe.2022.922848] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
The vertebral body’s Hounsfield unit (HU) value can credibly reflect patients’ bone mineral density (BMD). Given that poor bone-screw integration initially triggers screw loosening and regional differences in BMD and strength in the vertebral body exist, HU in screw holding planes should better predict screw loosening. According to the stress shielding effect, the stress distribution changes in the fixation segment with BMD reduction should be related to screw loosening, but this has not been identified. We retrospectively collected the radiographic and demographic data of 56 patients treated by single-level oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) screw fixation. BMD was identified by measuring HU values in vertebral bodies and screw holding planes. Regression analyses identified independent risk factors for cranial and caudal screw loosening separately. Meanwhile, OLIF with ALSR fixation was numerically simulated; the elastic modulus of bony structures was adjusted to simulate different grades of BMD reduction. Stress distribution changes were judged by computing stress distribution in screws, bone-screw interfaces, and cancellous bones in the fixation segment. The results showed that HU reduction in vertebral bodies and screw holding planes were independent risk factors for screw loosening. The predictive performance of screw holding plane HU is better than the mean HU of vertebral bodies. Cranial screws suffer a higher risk of screw loosening, but HU was not significantly different between cranial and caudal sides. The poor BMD led to stress concentrations on both the screw and bone-screw interfaces. Biomechanical deterioration was more severe in the cranial screws than in the caudal screws. Additionally, lower stress can also be observed in fixation segments’ cancellous bone. Therefore, a higher proportion of ALSR load transmission triggers stress concentration on the screw and bone-screw interfaces in patients with poor BMD. This, together with decreased bony strength in the screw holding position, contributes to screw loosening in osteoporotic patients biomechanically. The trajectory optimization of ALSR screws based on preoperative HU measurement and regular anti-osteoporosis therapy may effectively reduce the risk of screw loosening.
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Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhi-Qiang Yang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
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20
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Zhang S, Liu W, Chen S, Wang B, Wang P, Hu B, Lv X, Shao Z. Extracellular matrix in intervertebral disc: basic and translational implications. Cell Tissue Res 2022; 390:1-22. [DOI: 10.1007/s00441-022-03662-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 06/23/2022] [Indexed: 02/06/2023]
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Importance of Matrix Cues on Intervertebral Disc Development, Degeneration, and Regeneration. Int J Mol Sci 2022; 23:ijms23136915. [PMID: 35805921 PMCID: PMC9266338 DOI: 10.3390/ijms23136915] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 01/25/2023] Open
Abstract
Back pain is one of the leading causes of disability worldwide and is frequently caused by degeneration of the intervertebral discs. The discs’ development, homeostasis, and degeneration are driven by a complex series of biochemical and physical extracellular matrix cues produced by and transmitted to native cells. Thus, understanding the roles of different cues is essential for designing effective cellular and regenerative therapies. Omics technologies have helped identify many new matrix cues; however, comparatively few matrix molecules have thus far been incorporated into tissue engineered models. These include collagen type I and type II, laminins, glycosaminoglycans, and their biomimetic analogues. Modern biofabrication techniques, such as 3D bioprinting, are also enabling the spatial patterning of matrix molecules and growth factors to direct regional effects. These techniques should now be applied to biochemically, physically, and structurally relevant disc models incorporating disc and stem cells to investigate the drivers of healthy cell phenotype and differentiation. Such research will inform the development of efficacious regenerative therapies and improved clinical outcomes.
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22
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Martin JT, Wesorick B, Oldweiler AB, Kosinski AS, Goode AP, DeFrate LE. In vivo fluid transport in human intervertebral discs varies by spinal level and disc region. JOR Spine 2022; 5:e1199. [PMID: 35783907 PMCID: PMC9238288 DOI: 10.1002/jsp2.1199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 12/25/2022] Open
Abstract
Background The lumbar discs are large, dense tissues that are primarily avascular, and cells residing in the central region of the disc are up to 6-8 mm from the nearest blood vessel in adults. To maintain homeostasis, disc cells rely on nutrient transport between the discs and adjacent vertebrae. Thus, diminished transport has been proposed as a factor in age-related disc degeneration. Methods In this study, we used magnetic resonance imaging (MRI) to quantify diurnal changes in T2 relaxation time, an MRI biomarker related to disc hydration, to generate 3D models of disc fluid distribution and determine how diurnal changes in fluid varied by spinal level. We recruited 10 participants (five males/five females; age: 21-30 years; BMI: 19.1-29.0 kg/m2) and evaluated the T2 relaxation time of each disc at 8:00 AM and 7:00 PM, as well as degeneration grade (Pfirrmann). We also measured disc height, volume, and perimeter in a subset of individuals as a preliminary comparison of geometry and transport properties. Results We found that the baseline (AM) T2 relaxation time and the diurnal change in T2 relaxation time were greatest in the cranial lumbar discs, decreasing along the lumbar spine from cranial to caudal. In cranial discs, T2 relaxation times decreased in each disc region (nucleus pulposus [NP], inner annulus fibrosus [IAF], and outer annulus fibrosus [OAF]), whereas in caudal discs, T2 relaxation times decreased in the NP but increased in the AF. Conclusions Fluid transport varied by spinal level, where transport was greatest in the most cranial lumbar discs and decreased from cranial to caudal along the lumbar spine. Future work should evaluate what level-dependent factors affect transport.
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Affiliation(s)
- John T. Martin
- Department of Orthopaedic SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Benjamin Wesorick
- Department of Orthopaedic SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of Biomedical EngineeringDuke UniversityDurhamNorth CarolinaUSA
| | - Alexander B. Oldweiler
- Department of Orthopaedic SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Andrzej S. Kosinski
- Duke Clinical Research InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of Biostatistics and BioinformaticsDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Adam P. Goode
- Department of Orthopaedic SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
- Duke Clinical Research InstituteDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of Population Health SciencesDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Louis E. DeFrate
- Department of Orthopaedic SurgeryDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of Biomedical EngineeringDuke UniversityDurhamNorth CarolinaUSA
- Department of Mechanical Engineering and Materials ScienceDuke UniversityDurhamNorth CarolinaUSA
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23
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Li JC, Xie TH, Zhang Z, Song ZT, Song YM, Zeng JC. The Mismatch Between Bony Endplates and Grafted Bone Increases Screw Loosening Risk for OLIF Patients With ALSR Fixation Biomechanically. Front Bioeng Biotechnol 2022; 10:862951. [PMID: 35464717 PMCID: PMC9023805 DOI: 10.3389/fbioe.2022.862951] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/24/2022] [Indexed: 12/26/2022] Open
Abstract
The mismatch between bony endplates (BEPs) and grafted bone (GB) triggers several complications biomechanically. However, no published study has identified whether this factor increases the risk of screw loosening by deteriorating the local stress levels. This study aimed to illustrate the biomechanical effects of the mismatch between BEP and GB and the related risk of screw loosening. In this study, radiographic and demographic data of 56 patients treated by single segment oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) fixation were collected retrospectively, and the match sufficiency between BEP and GB was measured and presented as the grafted bony occupancy rate (GBOR). Data in patients with and without screw loosening were compared; regression analyses identified independent risk factors. OLIF with different GBORs was simulated in a previously constructed and validated lumbosacral model, and biomechanical indicators related to screw loosening were computed in surgical models. The radiographic review and numerical simulations showed that the coronal plane’s GBOR was significantly lower in screw loosening patients both in the cranial and caudal vertebral bodies; the decrease in the coronal plane’s GBOR has been proven to be an independent risk factor for screw loosening. In addition, numerical mechanical simulations showed that the poor match between BEP and GB will lead to stress concentration on both screws and bone-screw interfaces. Therefore, we can conclude that the mismatch between the BEP and GB will increase the risk of screw loosening by deteriorating local stress levels, and the increase in the GBOR by modifying the OLIF cage’s design may be an effective method to optimize the patient’s prognosis.
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Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhuang Zhang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
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Xiao L, Hu B, Ding B, Zhao Q, Liu C, Öner FC, Xu H. N(6)-methyladenosine RNA methyltransferase like 3 inhibits extracellular matrix synthesis of endplate chondrocytes by downregulating sex-determining region Y-Box transcription factor 9 expression under tension. Osteoarthritis Cartilage 2022; 30:613-625. [PMID: 35007741 DOI: 10.1016/j.joca.2022.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Tension stimulation is an important inducer of endplate cartilage degeneration, but the specific regulatory mechanism remains unclear. This study was the first to reveal the mechanism by which methyltransferase-like 3 (METTL3)-mediated N(6)-methyladenosine (m6A) modification affected the extracellular matrix anabolism by tension-induced endplate chondrocytes. METHOD We examined the differences in METTL3 expression and m6A methylation levels in human endplate chondrocytes and human cartilage endplate tissues under in vitro tension. The effect on endplate cartilage degeneration was evaluated by manipulating m6A methylation mediated by METTL3 in vivo and in vitro. The effect of METTL3-mediated m6A methylation on the stability of sex-determining region Y-box transcription factor 9 (SOX9) gene expression was determined experimentally. RESULTS METTL3 expression and m6A methylation levels were significantly increased in degenerative human endplate cartilage tissue. Similarly, tension stimulation inhibited the ability of human endplate chondrocytes to synthesize extracellular matrix, which was accompanied by an increase in METTL3-mediated m6A methylation. The ability of endplate chondrocytes to resist tension was significantly enhanced by inhibiting METTL3 expression and subsequently downregulating m6A methylation in vitro and in vivo, thereby reducing intervertebral disc degeneration. Furthermore, METTL3 mediated SOX9 RNA methylation and disrupted SOX9 mRNA stability, thereby inhibiting the gene expression of the downstream collagen type II alpha 1 chain. CONCLUSION Tension stimulation downregulated SOX9 expression through METTL3-mediated m6A methylation, thereby inhibiting the synthesis of extracellular matrix in endplate chondrocytes.
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Affiliation(s)
- L Xiao
- Department of Spine Surgery, Yijishan Hospital of Wannan Medical College, No. 2 Zheshan West Road, Wuhu, Anhui, 241001, China
| | - B Hu
- Spine Research Center of Wannan Medical College, No.22 Wenchang West Road, Wuhu, Anhui, 241001, China
| | - B Ding
- Spine Research Center of Wannan Medical College, No.22 Wenchang West Road, Wuhu, Anhui, 241001, China
| | - Q Zhao
- Department of Spine Surgery, Yijishan Hospital of Wannan Medical College, No. 2 Zheshan West Road, Wuhu, Anhui, 241001, China
| | - C Liu
- Key Laboratory of Non-Coding RNA Transformation Research of Anhui Higher Education Institution, No. 2 Zheshan West Road, Wuhu, Anhui, 241001, China
| | - F C Öner
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan, 1003508, Netherlands.
| | - H Xu
- Spine Research Center of Wannan Medical College, No.22 Wenchang West Road, Wuhu, Anhui, 241001, China.
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RETREG1-mediated ER-phagy activation induced by glucose deprivation alleviates nucleus pulposus cell damage via ER stress pathway. Acta Biochim Biophys Sin (Shanghai) 2022; 54:524-536. [PMID: 35607959 PMCID: PMC9828542 DOI: 10.3724/abbs.2022024] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Accumulating evidence indicates that ER-phagy serves as a key adaptive regulatory mechanism in response to various stress conditions. However, the exact mechanisms underlying ER-phagy in the pathogenesis of intervertebral disc degeneration remain largely unclear. In the present study, we demonstrated that RETREG1-mediated ER-phagy is induced by glucose deprivation (GD) treatment, along with ER stress activation and cell function decline. Importantly, ER-phagy was shown to be crucial for cell survival under GD conditions. Furthermore, ER stress was suggested as an upstream event of ER-phagy upon GD treatment and upregulation of ER-phagy could counteract the ER stress response. Therefore, our findings indicate that RETREG1-mediated ER-phagy activation protects against GD treatment-induced cell injury via modulating ER stress in human nucleus pulposus cells.
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Negative biomechanical effects of large grade nuclectomy in the transforaminal endoscopic discectomy increased the risk of adjacent segment diseases: A finite element study. J Clin Neurosci 2021; 93:141-146. [PMID: 34656238 DOI: 10.1016/j.jocn.2021.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 11/20/2022]
Abstract
PURPOSE The protection of articular processes (AP) in the transforaminal endoscopic discectomy (TED) was proven to optimise post-operative biomechanical environments. Published studies reported a large grade of nuclectomy leading to poor prognosis, but the underlying biomechanical mechanism was unclearly illustrated. This study aimed to investigate the changes of biomechanical environments after an in-out TED with intact AP and a large grade of nuclectomy and an out-in TED with limited foraminoplasty and a smaller grade of nuclectomy. METHODS A previously constructed and validated lumbo-sacral model was used in this study, and in-out TED with intact AP and out-in TED with limited foraminoplasty, a smaller grade of nuclectomy was simulated. Biomechanical changes in the L5-S1 segment related to the degeneration acceleration were computed under different directional loading conditions. RESULTS Post-operative biomechanical changes after the out-in TED with limited foraminoplasty were slight, except for the facet contact pressure under the extension position. By contrast, significant biomechanical deterioration, both in the adjacent disc and zygapophyseal joints, is observed under extension in the model after the in-out TED with large nuclectomy. CONCLUSION A large grade of nuclectomy is regarded as an independent risk factor of adjacent segment disease in the caudal functional spinal unit after the in-out TED.
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The potential role of melatonin in retarding intervertebral disc ageing and degeneration: A systematic review. Ageing Res Rev 2021; 70:101394. [PMID: 34139338 DOI: 10.1016/j.arr.2021.101394] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/08/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022]
Abstract
Intervertebral disc degeneration (IDD) is a common degenerative disease of the musculoskeletal system that develops with age. It is regarded as the main cause of chronic low back pain in the elderly. IDD has various causes, including ageing, mechanical overloading, and nutritional deficiency. Melatonin is a pleiotropic indole hormone secreted by the pineal gland and plays an important role in resisting various degenerative diseases. The serum levels of melatonin decline with age and are reported to be negatively correlated with the symptomatic and histopathological scores of IDD. In vivo studies have shown that exogenous administration of melatonin could maintain the structural integrity of the intervertebral disc and inhibit the development of IDD. Mechanistically, by interacting with its membrane or intracellular receptors, melatonin can promote autophagic flux, scavenge free radicals, inhibit the release of pro-inflammatory factors, and block apoptotic pathways, thereby enhancing anti-stress abilities and matrix anabolism in different types of disc cells. Therefore, melatonin supplementation may be a promising therapeutic strategy for IDD. This review aimed to summarize the latest findings regarding the therapeutic potential of melatonin in IDD.
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Small Extracellular Vesicles Derived from Adipocytes Attenuate Intervertebral Disc Degeneration in Rats by Rejuvenating Senescent Nucleus Pulposus Cells and Endplate Cells by Delivering Exogenous NAMPT. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:9955448. [PMID: 34434488 PMCID: PMC8382538 DOI: 10.1155/2021/9955448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/24/2021] [Accepted: 07/30/2021] [Indexed: 01/15/2023]
Abstract
Cellular senescence is a key factor in the development of intervertebral disc degeneration (IVDD). Age-associated decreases in NAD+ levels play a critical role in regulating cellular senescence. Previous studies have found that small extracellular vesicles (sEVs) secreted by adipocytes (Adipo-sEVs) or adipose tissue are abundant in nicotinamide phosphoribosyltransferase (NAMPT), which is the key NAD+ biosynthetic enzyme in mammals. Systemic injection of these sEVs significantly improves physical activity and extends the lifespan of aged mice by increasing NAD+ levels. However, to date, the therapeutic potential of Adipo-sEVs in other age-associated disease models, such as IVDD, has not been explored. In this study, we investigated the therapeutic effects of Adipo-sEVs on senescence of nucleus pulposus cells (NPCs) and cartilaginous endplate cells (EPCs). In vitro, Adipo-sEVs could rejuvenate the senescence of NPCs and EPCs. Age-related dysfunctions were also ameliorated by Adipo-sEVs by delivering NAMPT and activating NAD+ biosynthesis and the Sirt1 pathway. Further in vivo experiments revealed that Adipo-sEV-mediated delivery of NAMPT attenuated IVDD in rats by rejuvenating senescent NPCs and EPCs. Collectively, the results indicate a new cell-free tool and provide a promising sEV-mediated delivery method of NAMPT as a therapeutic approach for IVDD clinically.
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Wang L, Han M, Wong J, Zheng P, Lazar AA, Krug R, Fields AJ. Evaluation of human cartilage endplate composition using MRI: Spatial variation, association with adjacent disc degeneration, and in vivo repeatability. J Orthop Res 2021; 39:1470-1478. [PMID: 32592504 PMCID: PMC7765737 DOI: 10.1002/jor.24787] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/02/2020] [Accepted: 06/24/2020] [Indexed: 02/04/2023]
Abstract
Cartilage endplate (CEP) biochemical composition may influence disc degeneration and regeneration. However, evaluating CEP composition in patients remains a challenge. We used T2* mapping from ultrashort echo-time (UTE) magnetic resonance imaging (MRI), which is sensitive to CEP hydration, to investigate spatial variations in CEP T2* values and to determine how CEP T2* values correlate with adjacent disc degeneration. Thirteen human cadavers (56.4 ± 12.7 years) and seven volunteers (36.9 ± 10.9 years) underwent 3T MRI, including UTE and T1ρ mapping sequences. Spatial mappings of T2* values in L4-S1 CEPs were generated from UTE images and compared between subregions. In the abutting discs, mean T1ρ values in the nucleus pulposus were compared between CEPs with high vs low T2* values. To assess in vivo repeatability, precision errors in mean T2* values, and intraclass correlation coefficients (ICC) were measured from repeat scans. Results showed that CEP T2* values were highest centrally and lowest posteriorly. In the youngest individuals (<50 years), who had mild-to-moderately degenerated Pfirrmann grade II-III discs, low CEP T2* values associated with severer disc degeneration: T1ρ values were 26.7% lower in subjects with low CEP T2* values (P = .025). In older individuals, CEP T2* values did not associate with disc degeneration (P = .39-.62). Precision errors in T2* ranged from 1.7 to 2.6 ms, and reliability was good-to-excellent (ICC = 0.89-0.94). These findings suggest that deficits in CEP composition, as indicated by low T2* values, associate with severer disc degeneration during the mild-to-moderate stages. Measuring CEP T2* values with UTE MRI may clarify the role of CEP composition in patients with mild-to-moderate disc degeneration.
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Affiliation(s)
- Linshanshan Wang
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCalifornia
| | - Misung Han
- Department of Radiology & Biomedical ImagingUniversity of CaliforniaSan FranciscoCalifornia
| | - Jason Wong
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCalifornia
| | - Patricia Zheng
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCalifornia
| | - Ann A. Lazar
- Department of Epidemiology and BiostatisticsUniversity of CaliforniaSan FranciscoCalifornia,Department of Preventive and Restorative Dental SciencesUniversity of CaliforniaSan FranciscoCalifornia
| | - Roland Krug
- Department of Radiology & Biomedical ImagingUniversity of CaliforniaSan FranciscoCalifornia
| | - Aaron J. Fields
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCalifornia
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30
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Wu X, Liu Y, Du J, Li X, Lin J, Ni L, Zhu P, Zhou H, Kong F, Yang H, Geng D, Mao H. Melatonin Attenuates Intervertebral Disk Degeneration via Maintaining Cartilaginous Endplate Integrity in Rats. Front Physiol 2021; 12:672572. [PMID: 34220535 PMCID: PMC8248798 DOI: 10.3389/fphys.2021.672572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/10/2021] [Indexed: 01/08/2023] Open
Abstract
Objective The aim of this study is to verify whether melatonin (Mel) could mitigate intervertebral disk degeneration (IVDD) in rats and to investigate the potential mechanism of it. Method A rat acupuncture model of IVDD was established with intraperitoneal injection of Mel. The effect of Mel on IVDD was analyzed via radiologic and histological evaluations. The specific Mel receptors were investigated in both the nucleus pulposus (NP) and cartilaginous endplates (EPs). In vitro, EP cartilaginous cells (EPCs) were treated by different concentrations of Mel under lipopolysaccharide (LPS) and Luzindole conditions. In addition, LPS-induced inflammatory response and matrix degradation following nuclear factor kappa-B (NF-κB) pathway activation were investigated to confirm the potential mechanism of Mel on EPCs. Results The percent disk height index (%DHI) and MRI signal decreased after initial puncture in the degeneration group compared with the control group, while Mel treatment protected disk height from decline and prevented the loss of water during the degeneration process. In the meantime, the histological staining of the Mel groups showed more integrity and well-ordered construction of the NP and EPs in both low and high concentration than that of the degeneration group. In addition, more deep-brown staining of type II collagen (Coll-II) was shown in the Mel groups compared with the degeneration group. Furthermore, in rat samples, immunohistochemical staining showed more positive cells of Mel receptors 1a and 1b in the EPs, instead of in the NP. Moreover, evident osteochondral lacuna formation was observed in rat EPs in the degeneration group; after Mel treatment, the osteochondral destruction alleviated accompanying fewer receptor activator for nuclear factor-κB ligand (RANKL) and tartrate-resistant acid phosphatase (TRAP)-stained positive cells expressed in the EPs. In vitro, Mel could promote the proliferation of EPCs, which protected EPCs from degeneration under LPS treatment. What is more, Mel downregulated the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway through binding to its specific receptors. Conclusion These results indicate that Mel protects the integrity of the EPs and attenuates IVDD by binding to the Mel receptors in the EPs. It may alleviate the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway.
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Affiliation(s)
- Xiexing Wu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yijie Liu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiacheng Du
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiaoping Li
- Department of Clinical Education, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiayi Lin
- Department of Orthopedics Center, Ningbo No. 2 Hospital, Ningbo, China
| | - Li Ni
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Pengfei Zhu
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hong Zhou
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Fanchen Kong
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Huilin Yang
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Dechun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiqing Mao
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
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Lee NN, Salzer E, Bach FC, Bonilla AF, Cook JL, Gazit Z, Grad S, Ito K, Smith LJ, Vernengo A, Wilke H, Engiles JB, Tryfonidou MA. A comprehensive tool box for large animal studies of intervertebral disc degeneration. JOR Spine 2021; 4:e1162. [PMID: 34337336 PMCID: PMC8313180 DOI: 10.1002/jsp2.1162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/12/2022] Open
Abstract
Preclinical studies involving large animal models aim to recapitulate the clinical situation as much as possible and bridge the gap from benchtop to bedside. To date, studies investigating intervertebral disc (IVD) degeneration and regeneration in large animal models have utilized a wide spectrum of methodologies for outcome evaluation. This paper aims to consolidate available knowledge, expertise, and experience in large animal preclinical models of IVD degeneration to create a comprehensive tool box of anatomical and functional outcomes. Herein, we present a Large Animal IVD Scoring Algorithm based on three scales: macroscopic (gross morphology, imaging, and biomechanics), microscopic (histological, biochemical, and biomolecular analyses), and clinical (neurologic state, mobility, and pain). The proposed algorithm encompasses a stepwise evaluation on all three scales, including spinal pain assessment, and relevant structural and functional components of IVD health and disease. This comprehensive tool box was designed for four commonly used preclinical large animal models (dog, pig, goat, and sheep) in order to facilitate standardization and applicability. Furthermore, it is intended to facilitate comparison across studies while discerning relevant differences between species within the context of outcomes with the goal to enhance veterinary clinical relevance as well. Current major challenges in pre-clinical large animal models for IVD regeneration are highlighted and insights into future directions that may improve the understanding of the underlying pathologies are discussed. As such, the IVD research community can deepen its exploration of the molecular, cellular, structural, and biomechanical changes that occur with IVD degeneration and regeneration, paving the path for clinically relevant therapeutic strategies.
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Affiliation(s)
- Naomi N. Lee
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Elias Salzer
- Orthopaedic Biomechanics, Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
| | - Frances C. Bach
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
| | - Andres F. Bonilla
- Preclinical Surgical Research Laboratory, Department of Clinical SciencesColorado State UniversityColoradoUSA
| | - James L. Cook
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Zulma Gazit
- Department of SurgeryCedars‐Sinai Medical CenterLos AngelesCaliforniaUSA
| | | | - Keita Ito
- Orthopaedic Biomechanics, Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
| | - Lachlan J. Smith
- Departments of Neurosurgery and Orthopaedic SurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Andrea Vernengo
- AO Research Institute DavosDavosSwitzerland
- Department of Chemical EngineeringRowan UniversityGlassboroNew JerseyUSA
| | - Hans‐Joachim Wilke
- Institute of Orthopaedic Research and BiomechanicsUniversity Hospital UlmUlmGermany
| | - Julie B. Engiles
- Department of Pathobiology, New Bolton Center, School of Veterinary MedicineUniversity of PennsylvaniaKennett SquarePennsylvaniaUSA
| | - Marianna A. Tryfonidou
- Department of Clinical Sciences, Faculty of Veterinary MedicineUtrecht UniversityUtrechtThe Netherlands
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Newman HR, DeLucca JF, Peloquin JM, Vresilovic EJ, Elliott DM. Multiaxial validation of a finite element model of the intervertebral disc with multigenerational fibers to establish residual strain. JOR Spine 2021; 4:e1145. [PMID: 34337333 PMCID: PMC8313175 DOI: 10.1002/jsp2.1145] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 01/20/2023] Open
Abstract
Finite element models of the intervertebral disc are used to address research questions that cannot be tested through typical experimentation. A disc model requires complex geometry and tissue properties to be accurately defined to mimic the physiological disc. The physiological disc possesses residual strain in the annulus fibrosus (AF) due to osmotic swelling and due to inherently pre-strained fibers. We developed a disc model with residual contributions due to swelling-only, and a multigeneration model with residual contributions due to both swelling and AF fiber pre-strain and validated it against organ-scale uniaxial, quasi-static and multiaxial, dynamic mechanical tests. In addition, we demonstrated the models' ability to mimic the opening angle observed following radial incision of bovine discs. Both models were validated against organ-scale experimental data. While the swelling only model responses were within the experimental 95% confidence interval, the multigeneration model offered outcomes closer to the experimental mean and had a bovine model opening angle within one SD of the experimental mean. The better outcomes for the multigeneration model, which allowed for the inclusion of inherently pre-strained fibers in AF, is likely due to its uniform fiber contribution throughout the AF. We conclude that the residual contribution of pre-strained fibers in the AF should be included to best simulate the physiological disc and its behaviors.
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Affiliation(s)
- Harrah R. Newman
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - John F. DeLucca
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - John M. Peloquin
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
| | - Edward J. Vresilovic
- Department of Orthopaedic SurgeryUniversity of Pennsylvania Medical CenterHersheyPennsylvaniaUSA
| | - Dawn M. Elliott
- Department of Biomedical EngineeringUniversity of DelawareNewarkDelawareUSA
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Ashinsky B, Smith HE, Mauck RL, Gullbrand SE. Intervertebral disc degeneration and regeneration: a motion segment perspective. Eur Cell Mater 2021; 41:370-380. [PMID: 33763848 PMCID: PMC8607668 DOI: 10.22203/ecm.v041a24] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Back and neck pain have become primary reasons for disability and healthcare spending globally. While the causes of back pain are multifactorial, intervertebral disc degeneration is frequently cited as a primary source of pain. The annulus fibrosus (AF) and nucleus pulposus (NP) subcomponents of the disc are common targets for regenerative therapeutics. However, disc degeneration is also associated with degenerative changes to adjacent spinal tissues, and successful regenerative therapies will likely need to consider and address the pathology of adjacent spinal structures beyond solely the disc subcomponents. This review summarises the current state of knowledge in the field regarding associations between back pain, disc degeneration, and degeneration of the cartilaginous and bony endplates, the AF-vertebral body interface, the facet joints and spinal muscles, in addition to a discussion of regenerative strategies for treating pain and degeneration from a whole motion segment perspective.
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Affiliation(s)
| | | | | | - S E Gullbrand
- Corporal Michael J. Crescenz VA Medical Centre, Research, Building 21, Rm A214, 3900 Woodland Ave, Philadelphia, PA 19104,
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Baumgartner L, Wuertz-Kozak K, Le Maitre CL, Wignall F, Richardson SM, Hoyland J, Ruiz Wills C, González Ballester MA, Neidlin M, Alexopoulos LG, Noailly J. Multiscale Regulation of the Intervertebral Disc: Achievements in Experimental, In Silico, and Regenerative Research. Int J Mol Sci 2021; 22:E703. [PMID: 33445782 PMCID: PMC7828304 DOI: 10.3390/ijms22020703] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/17/2022] Open
Abstract
Intervertebral disc (IVD) degeneration is a major risk factor of low back pain. It is defined by a progressive loss of the IVD structure and functionality, leading to severe impairments with restricted treatment options due to the highly demanding mechanical exposure of the IVD. Degenerative changes in the IVD usually increase with age but at an accelerated rate in some individuals. To understand the initiation and progression of this disease, it is crucial to identify key top-down and bottom-up regulations' processes, across the cell, tissue, and organ levels, in health and disease. Owing to unremitting investigation of experimental research, the comprehension of detailed cell signaling pathways and their effect on matrix turnover significantly rose. Likewise, in silico research substantially contributed to a holistic understanding of spatiotemporal effects and complex, multifactorial interactions within the IVD. Together with important achievements in the research of biomaterials, manifold promising approaches for regenerative treatment options were presented over the last years. This review provides an integrative analysis of the current knowledge about (1) the multiscale function and regulation of the IVD in health and disease, (2) the possible regenerative strategies, and (3) the in silico models that shall eventually support the development of advanced therapies.
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Affiliation(s)
- Laura Baumgartner
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
| | - Karin Wuertz-Kozak
- Department of Biomedical Engineering, Rochester Institute of Technology (RIT), Rochester, NY 14623, USA;
- Schön Clinic Munich Harlaching, Spine Center, Academic Teaching Hospital and Spine Research Institute of the Paracelsus Medical University Salzburg (Austria), 81547 Munich, Germany
| | - Christine L. Le Maitre
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK;
| | - Francis Wignall
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Stephen M. Richardson
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Judith Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Carlos Ruiz Wills
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
| | - Miguel A. González Ballester
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
- Catalan Institution for Research and Advanced Studies (ICREA), Pg. Lluis Companys 23, 08010 Barcelona, Spain
| | - Michael Neidlin
- Department of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece; (M.N.); (L.G.A.)
| | - Leonidas G. Alexopoulos
- Department of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece; (M.N.); (L.G.A.)
| | - Jérôme Noailly
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
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35
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Lakstins K, Arnold L, Gunsch G, Khan S, Moore S, Purmessur D. Characterization of bovine and canine animal model cartilage endplates and comparison to human cartilage endplate structure, matrix composition, and cell phenotype. JOR Spine 2020; 3:e1116. [PMID: 33392453 PMCID: PMC7770203 DOI: 10.1002/jsp2.1116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/20/2020] [Accepted: 05/28/2020] [Indexed: 12/19/2022] Open
Abstract
There is a need to further explore mechanisms of cartilage endplate (CEP) degeneration, due to its role in the onset and progression of intervertebral disc degeneration and low back pain. Therefore, the goal of this study was to evaluate structure, matrix composition, and cell phenotype between the human and bovine or canine, both clinically relevant animal models currently used to study the intervertebral disc, CEP. This information may be used in addition to other relevant studies, to help determine optimal animal models for use in studying the role of the CEP in intervertebral disc degeneration and back pain. Endplate structure, matrix composition, cell morphology, and gene expression were evaluated using a picrosirius red/alcian blue and hematoxylin and eosin stain, a dimethylmethylene blue assay, and quantitative reverse transcription polymerase chain reaction. The bovine and canine CEPs were thinner with more rounded cells and thicker bony endplates. The canine CEP contained significantly more sulfated glycosaminoglycans. The bovine CEP demonstrated higher expression of ACAN, COL1, and COL2 and lower expression of T, FBLN1, and collagen X (COLX) compared to the human CEP. The canine CEP had higher COL2 and lower COL1, KRT19, MKX, FBLN1, COLX expression compared to human. These similarities and differences between human and bovine or canine CEP are important to consider when evaluating which animal model is most optimal to use in future studies, interpreting research findings using these animal models and assessing translatability to the human condition.
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Affiliation(s)
- Katherine Lakstins
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Lauren Arnold
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Gilian Gunsch
- Department of BiologyThe Ohio State UniversityColumbusOhioUSA
| | - Safdar Khan
- Department of OrthopaedicsThe Ohio State UniversityColumbusOhioUSA
| | - Sarah Moore
- Department of Veterinary Clinical SciencesThe Ohio State UniversityColumbusOhioUSA
| | - Devina Purmessur
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
- Department of OrthopaedicsThe Ohio State UniversityColumbusOhioUSA
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36
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Zhang C, Gullbrand SE, Schaer TP, Boorman S, Elliott DM, Chen W, Dodge GR, Mauck RL, Malhotra NR, Smith LJ. Combined Hydrogel and Mesenchymal Stem Cell Therapy for Moderate-Severity Disc Degeneration in Goats. Tissue Eng Part A 2020; 27:117-128. [PMID: 32546053 DOI: 10.1089/ten.tea.2020.0103] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Intervertebral disc degeneration is a cascade of cellular, structural, and biomechanical changes that is strongly implicated as a cause of low-back pain. Current treatment strategies have poor long-term efficacy as they seek only to alleviate symptoms without preserving or restoring native tissue structure and function. The objective of this study was to evaluate the efficacy of a combined triple interpenetrating network hydrogel (comprising dextran, chitosan, and teleostean) and mesenchymal stem cell (MSC) therapy targeting moderate-severity disc degeneration in a clinically relevant goat model. Degeneration was induced in lumbar discs of 10 large frame goats by injection of chondroitinase ABC. After 12 weeks, degenerate discs were treated by injection of either hydrogel alone or hydrogel seeded with allogeneic, bone marrow-derived MSCs. Untreated healthy and degenerate discs served as controls, and animals were euthanized 2 weeks after treatment. Discs exhibited a significant loss of disc height 12 weeks after degeneration was induced. Two weeks after treatment, discs that received the combined hydrogel and MSC injection exhibited a significant, 10% improvement in disc height index, as well as improvements in histological condition. Discs that were treated with hydrogel alone exhibited reduced tumor necrosis factor-α expression in the nucleus pulposus (NP). Microcomputed tomography imaging revealed that the hydrogel remained localized to the central NP region of all treated discs after 2 weeks of unrestricted activity. These encouraging findings motivate further, longer term studies of therapeutic efficacy of hydrogel and MSC injections in this large animal model. Impact statement Low-back pain is the leading cause of disability worldwide, and degeneration of the intervertebral discs is considered to be one of the most common reasons for low-back pain. Current treatment strategies focus solely on alleviation of symptoms, and there is a critical need for new treatments that also restore disc structure and function. In this study, using a clinically relevant goat model of moderate-severity disc degeneration, we demonstrate that a combined interpenetrating network hydrogel and mesenchymal stem cell therapy provides acute improvements in disc height, histological condition, and local inflammation.
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Affiliation(s)
- Chenghao Zhang
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sarah E Gullbrand
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Thomas P Schaer
- Comparative Orthopaedic Research Laboratory, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Sophie Boorman
- Comparative Orthopaedic Research Laboratory, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Dawn M Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Weiliam Chen
- Department of Surgery, New York University School of Medicine, New York, New York, USA
| | - George R Dodge
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert L Mauck
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Neil R Malhotra
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lachlan J Smith
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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37
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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] [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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38
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Zhan JW, Wang SQ, Feng MS, Wei X, Yu J, Yin XL, Han T, Zhu LG. Constant compression decreases vascular bud and VEGFA expression in a rabbit vertebral endplate ex vivo culture model. PLoS One 2020; 15:e0234747. [PMID: 32584845 PMCID: PMC7316323 DOI: 10.1371/journal.pone.0234747] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 06/02/2020] [Indexed: 12/30/2022] Open
Abstract
SUMMARY OF BACKGROUND DATA The vascular buds in the vertebral endplate (VEP) are the structural foundation of nutrient exchange in the intervertebral disc (IVD). VEGF is closely related to angiogenesis in the endplate and intervertebral disc degeneration (IDD). OBJECTIVE To investigate the effects of static load on vascular buds and VEGF expression in the VEP and to further clarify the relation between IDD and VEGF. METHODS IVD motion segments were harvested from rabbit lumbar spines and cultured under no-loading conditions (controls) or in custom-made apparatuses under a constant compressive load (0.5 MPa) for up to 14 days. Tissue integrity and the number of vascular buds were determined, and the concentrations and expression of Aggrecan, COL2a1, and VEGFA in the VEPs were assessed after 3, 7, and 14 days of culturing and then compared with those of fresh tissues. RESULTS Under the constant compression, the morphological integrity of the VEPs was gradually disrupted, and immunohistochemistry results showed a significant decrease in the levels of Agg and COL2a1. During the static load, the number of vascular buds in the VEPs was gradually reduced from the early stage of culture, and ELISA showed that the constant compressive load caused a significant decrease in the VEGFA and VEGFR2 protein concentrations, which were consistent with the immunohistochemistry results. Western blot and RT-PCR results also showed that the loading state caused a significant decrease in VEGFA expression compared with that of fresh and control samples. CONCLUSIONS Constant compression caused degeneration of the VEP as well as a decreased number of vascular buds, thereby accelerating disc degeneration. VEGFA is involved in this process. We anticipate that regulating the expression of VEGFA may improve the condition of the lesions to the vascular buds in the endplates, thus enhancing the nutritional supply function in IVD and providing new therapeutic targets and strategies for the effective prevention and treatment of IDD.
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Affiliation(s)
- Jia-Wen Zhan
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shang-Quan Wang
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Min-Shan Feng
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xu Wei
- Scientific Research Office, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jie Yu
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xun-Lu Yin
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Tao Han
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Li-Guo Zhu
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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39
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Xiao ZF, Su GY, Hou Y, Chen SD, Zhao BD, He JB, Zhang JH, Chen YJ, Lin DK. Mechanics and Biology Interact in Intervertebral Disc Degeneration: A Novel Composite Mouse Model. Calcif Tissue Int 2020; 106:401-414. [PMID: 31912171 DOI: 10.1007/s00223-019-00644-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 11/27/2019] [Indexed: 12/16/2022]
Abstract
The aim of this study was to distinguish the characteristics of intervertebral disc degeneration (IVDD) originating from mechanics imbalance, biology disruption, and their communion, and to develop a composite IVDD model by ovariectomy combined with lumbar facetectomy for mimicking elderly IVDD with osteoporosis and lumbar spinal instability. Mice were randomly divided into four groups and subjected to sham surgery (CON), ovariectomy (OVX), facetectomy (mechanical instability, INS) or their combination (COM), respectively. Radiographical (n = 4) and histological changes (n = 8) of L4/5 spinal segments were analyzed. Tartrate-resistant acid phosphatase (TRAP) staining was conducted to detect osteoclasts, and expression of osterix (OSX), type I collagen (Col I), type II collagen (Col II) and vascular endothelial growth factor (VEGF) were evaluated by immunochemistry. OVX affected the body's metabolism but INS did not, as the body weight increased and uterus weight decreased in OVX and COM mice compared to CON and INS mice. OVX, INS, and COM caused IVDD in various degrees at 12 weeks after surgery. However, the major pathogeneses of OVX- and INS-induced IVDD were different, which focused on endplate (EP) remodeling and annulus fibrosus (AF) collapse, respectively. OVX induced osteopenia of vertebra. In contrast, INS promoted the stress-adaptive increase of subchondral bone trabeculae. The COM produced a reproducible severe IVDD model with characteristics of sparse vertebral trabeculae, cartilaginous EP ossification, subchondral bone sclerosis, fibrous matrix disorder, angiogenesis, disc stiffness, as well as space fusion. Additionally, all groups had elevated bone and cartilage turnover compared with CON group, as the quantity of trap + osteoclasts and the osteogenic OSX expression increased in these groups. Likewise, the VEGF expression levels were similar, accompanied by the altered matrix expression of disc, including the changed distribution and contents of Col II and Col I. The findings suggested that the composite mouse model to some extent could effectively mimic the interactions of biology and mechanics engaged in the onset and natural course of IVDD, which would be more compatible with the IVDD of elderly with vertebral osteoporosis and spinal instability and benefit to further clarify the complicated mechanobiological environment of elderly IVDD progression.
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Affiliation(s)
- Zhi-Feng Xiao
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Guo-Yi Su
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Yu Hou
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Shu-Dong Chen
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Bing-de Zhao
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Jian-Bo He
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Ji-Heng Zhang
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Yan-Jun Chen
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China
| | - Ding-Kun Lin
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong Provincial Academy of Chinese Medical Sciences, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, People's Republic of China.
- Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, People's Republic of China.
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Melatonin modulates IL-1β-induced extracellular matrix remodeling in human nucleus pulposus cells and attenuates rat intervertebral disc degeneration and inflammation. Aging (Albany NY) 2019; 11:10499-10512. [PMID: 31772145 PMCID: PMC6914432 DOI: 10.18632/aging.102472] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/06/2019] [Indexed: 02/07/2023]
Abstract
The inflammatory-associated factors interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are widely reported to be associated with intervertebral disc (IVD) degeneration (IVDD). N-acetyl-5-methoxytryptamine (melatonin) is a natural hormone secreted by the pineal gland which has been shown to participate in several physiological and pathological progresses, such as aging, anti-inflammation, anti-apoptosis and autophagy regulation. However, the effects of melatonin on IVD remain unclear. In the present study, we treated human nucleus pulposus cells (NPCs) with melatonin and discovered that melatonin could modulate extracellular matrix (ECM) remodeling induced by IL-1β by enhancing collagen II and aggrecan expression levels and by downregulating matrix metalloproteinase-3 (MMP-3) levels. These findings were verified by western blot and immunofluorescence assays. Intraperitoneal injection of melatonin mitigated IVDD in the rat tail puncture model. X-ray and magnetic resonance imaging (MRI), as well as hematoxylin-eosin (H&E), Safranine O-Green, Alcian blue and Celium red staining methods were adopted to evaluate IVDD grades, the structural integrity of nucleus pulposus (NP) and annulus fibrosus (AF) and the damage and calcification of the cartilage endplate. Melatonin reduced inflammatory cell aggregation and the release of the inflammatory factors IL-1β, IL-6, TNF-α as determined by immunohistochemistry. In conclusion, the present study demonstrated that melatonin could modulate ECM remodeling by IL-1β in vitro and attenuate the IVDD and induction of inflammation in a rat tail puncture model in vivo. The data demonstrated that melatonin may contribute to the restoration processs of IVD following damage and may be used as a potential novel therapy for IVDD.
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Nutrient supply and nucleus pulposus cell function: effects of the transport properties of the cartilage endplate and potential implications for intradiscal biologic therapy. Osteoarthritis Cartilage 2019; 27:956-964. [PMID: 30721733 PMCID: PMC6536352 DOI: 10.1016/j.joca.2019.01.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/19/2019] [Accepted: 01/25/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Intradiscal biologic therapy is a promising strategy for managing intervertebral disc degeneration. However, these therapies require a rich nutrient supply, which may be limited by the transport properties of the cartilage endplate (CEP). This study investigated how fluctuations in CEP transport properties impact nutrient diffusion and disc cell survival and function. DESIGN Human CEP tissues harvested from six fresh cadaveric lumbar spines (38-66 years old) were placed at the open sides of diffusion chambers. Bovine nucleus pulposus (NP) cells cultured inside the chambers were nourished exclusively by nutrients diffusing through the CEP tissues. After 72 h in culture, depth-dependent NP cell viability and gene expression were measured, and related to CEP transport properties and biochemical composition determined using fluorescence recovery after photobleaching and Fourier transform infrared (FTIR) spectroscopy. RESULTS Solute diffusivity varied nearly 4-fold amongst the CEPs studied, and chambers with the least permeable CEPs appeared to have lower aggrecan, collagen-2, and matrix metalloproteinase-2 gene expression, as well as a significantly shorter viable distance from the CEP/nutrient interface. Increasing chamber cell density shortened the viable distance; however, this effect was lost for low-diffusivity CEPs, which suggests that these CEPs may not provide enough nutrient diffusion to satisfy cell demands. Solute diffusivity in the CEP was associated with biochemical composition: low-diffusivity CEPs had greater amounts of collagen and aggrecan, more mineral, and lower cross-link maturity. CONCLUSIONS CEP transport properties dramatically affect NP cell survival/function. Degeneration-related CEP matrix changes could hinder the success of biologic therapies that require increased nutrient supply.
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Dolor A, Sampson SL, Lazar AA, Lotz JC, Szoka FC, Fields AJ. Matrix modification for enhancing the transport properties of the human cartilage endplate to improve disc nutrition. PLoS One 2019; 14:e0215218. [PMID: 30970007 PMCID: PMC6457523 DOI: 10.1371/journal.pone.0215218] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/28/2019] [Indexed: 02/07/2023] Open
Abstract
Poor solute transport through the cartilage endplate (CEP) impairs disc nutrition and could be a key factor that limits the success of intradiscal biologic therapies. Here we demonstrate that treating the CEP with matrix metalloproteinase-8 (MMP-8) reduces the matrix constituents that impede solute uptake and thereby improves nutrient diffusion. Human CEP tissues harvested from four fresh cadaveric lumbar spines (age range: 38-66 years old) were treated with MMP-8. Treatment caused a dose-dependent reduction in sGAG, localized reductions to the amount of collagen, and alterations to collagen structure. These matrix modifications corresponded with 16-24% increases in the uptake of a small solute (376 Da). Interestingly, the effects of MMP-8 treatment depended on the extent of non-enzymatic glycation: treated CEPs with high concentrations of advanced glycation end products (AGEs) exhibited the lowest uptake compared to treated CEPs with low concentrations of AGEs. Moreover, AGE concentrations were donor-specific, and the donor tissues with the highest AGE concentrations appeared to have lower uptake than would be expected based on the initial amounts of collagen and sGAG. Finally, increasing solute uptake in the CEP improved cell viability inside diffusion chambers, which supports the nutritional relevance of enhancing the transport properties of the CEP. Taken together, our results provide new insights and in vitro proof-of-concept for a treatment approach that could improve disc nutrition for biologic therapy: specifically, matrix reduction by MMP-8 can enhance solute uptake and nutrient diffusion through the CEP, and AGE concentration appears to be an important, patient-specific factor that influences the efficacy of this approach.
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Affiliation(s)
- Aaron Dolor
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States of America
| | - Sara L. Sampson
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, United States of America
| | - Ann A. Lazar
- Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA, United States of America
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, United States of America
| | - Jeffrey C. Lotz
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, United States of America
| | - Francis C. Szoka
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States of America
| | - Aaron J. Fields
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, United States of America
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Hu BW, Lv X, Chen SF, Shao ZW. Application of Finite Element Analysis for Investigation of Intervertebral Disc Degeneration: from Laboratory to Clinic. Curr Med Sci 2019; 39:7-15. [PMID: 30868485 DOI: 10.1007/s11596-019-1993-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 09/06/2018] [Indexed: 01/06/2023]
Abstract
Due to the ethical concern and inability to detect inner stress distributions of intervertebral disc (IVD), traditional methods for investigation of intervertebral disc degeneration (IVDD) have significant limitations. Many researchers have demonstrated that finite element analysis (FEA) is an effective tool for the research of IVDD. However, the specific application of FEA for investigation of IVDD has not been systematically elucidated before. In the present review, we summarize the current finite element models (FEM) used for the investigation of IVDD, including the poroelastic nonlinear FEM, diffusive-reactive theory model and cell-activity coupled mechano-electrochemical theory model. We further elaborate the use of FEA for the research of IVDD pathogenesis especially for nutrition and biomechanics associated etiology, and the biological, biomechanical and clinical influences of IVDD. In addition, the application of FEA for evaluation and exploration of various treatments for IVDD is also elucidated. We conclude that FEA is an excellent technique for research of IVDD, which could be used to explore the etiology, biology and biomechanics of IVDD. In the future, FEA may help us to achieve the goal of individualized precision therapy.
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Affiliation(s)
- Bin-Wu Hu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Xiao Lv
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Song-Feng Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Zeng-Wu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Zhang ZQ, Wang CS, Yang P, Wang KZ. Mesenchymal Stem Cells Induced by Microencapsulated Chondrocytes on Repairing of Intervertebral Disc Degeneration. Orthop Surg 2018; 10:328-336. [PMID: 30485683 DOI: 10.1111/os.12411] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 12/22/2017] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To evaluate the therapeutic effects of mesenchymal stem cells induced by microencapsulated chondrocytes on repairing of intervertebral disc degeneration. METHODS Rabbit chondrocytes and bone marrow-derived mesenchymal stem cells (MSC) were derived. Chondrocytes were microencapsulated by a microcapsule generator to produce microencapsulated chondrocytes (MEC). MSC were then co-cultured with MEC (MSC-MEC) and the properties and the therapeutic effects on repairing of intervertebral disc degeneration were studied. For the in vitro study, cell proliferation, type II collagen, and glycosaminoglycan (GAG) were studied. The MSC induced by chondrocytes in the Transwell system (MSC-MLC) and pure MSC were used as the control group. For the in vivo studied, MSC-MEC were implanted into the intervertebral disc degenerated (IDD) models, and the radiological images, biomechanical properties, collagen II, and histology of the discs were studied. The IDD, MSC, and MSC-MLC groups were used as the control group. RESULTS In the in vitro study, no significant differences were found among the three groups, indicating that the microcapsule co-culture system will not affect the proliferation of MSC. The type II collagen quantity secreted by MSC-MEC was 23.57 ± 2.46 ng/μL, which was more than for MSC-MLC (15.14 ± 2.31 ng/μL) and MSC groups (4.17 ± 1.23 ng/μL, all P < 0.025). GAG secreted by MSC-MEC was 0.184 ± 0.006 mg/well, which was more than for the MSC-MLC (0.151 ± 0.011 mg/well) and MSC groups (0.023 ± 0.002 mg/well, all P < 0.025). In the in vivo study, no obvious degenerative or protrusive disc was found in the MSC-MEC group, while protrusive discs could be found in the MSC-MLC group, and both degenerative and protrusive discs were found in MSC and IDD groups, which indicated that the reparative effects of MSC-MEC on degenerated discs were better than for the control groups. Biomechanical properties of discs in the MSC-MEC group were maintained at all four time points (2nd, 4th, 8th, and 16th week after implantation). The compressive strength (CS) and the elastic modulus (EM) of MSC and IDD groups were consistently decreased. The CS of the MSC-MLC group was increased in the 4th week but decreased again in the 8th week, while the EM of the MSC-MLC group consistently decreased. Western blot results indicated that discs of the MSC-MEC group had more collagen II, which is an important component of discs. Histology staining showed that the nucleus pulposus of MSC-MEC was complete; no obvious fragment of component loss was found, while those of MSC-MLC, MSC, and IDD groups were widened, broken, and hollow. CONCLUSION The microencapsulation method for half-contact co-culturing improves the differentiation extent of MSC, and MSC induced by chondrocytes could also be used for treatment of IDD.
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Affiliation(s)
- Zi-Qi Zhang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Chun-Sheng Wang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Pei Yang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Kun-Zheng Wang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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Sampson SL, Sylvia M, Fields AJ. Effects of dynamic loading on solute transport through the human cartilage endplate. J Biomech 2018; 83:273-279. [PMID: 30554819 DOI: 10.1016/j.jbiomech.2018.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 11/07/2018] [Accepted: 12/03/2018] [Indexed: 12/29/2022]
Abstract
Nutrient and metabolite transport through the cartilage endplate (CEP) is important for maintaining proper disc nutrition, but the mechanisms of solute transport remain unclear. One unresolved issue is the role of dynamic loading. In comparison to static loading, dynamic loading is thought to enhance transport by increasing convection. However, the CEP has a high resistance to fluid flow, which could limit solute convection. Here we measure solute transport through site-matched cadaveric human lumbar CEP tissues under static vs. dynamic loading, and we determine how the degree of transport enhancement from dynamic loading depends on CEP porosity and solute size. We found that dynamic loading significantly increased small and large solute transport through the CEP: on average, dynamic loading increased the transport of sodium fluorescein (376 Da) by a factor of 1.85 ± 0.64 and the transport of a large dextran (4000 Da) by a factor of 4.97 ± 3.05. Importantly, CEP porosity (0.65 ± 0.07; range: 0.47-0.76) strongly influenced the degree of transport enhancement. Specifically, for both solutes, transport enhancement was greater for CEPs with low porosity than for CEPs with high porosity. This is because the CEPs with low porosity were susceptible to larger improvements in fluid flow under dynamic loading. The CEP becomes less porous and less hydrated with aging and as disc degeneration progresses. Together, these findings suggest that as those changes occur, dynamic loading has a greater effect on solute transport through the CEP compared to static loading, and thus may play a larger role in disc nutrition.
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Affiliation(s)
- Sara L Sampson
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Meghan Sylvia
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Aaron J Fields
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.
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Abstract
Purpose of review The endplates form the interface between the rigid vertebral bodies and compliant intervertebral discs. Proper endplate function involves a balance between conflicting biomechanical and nutritional demands. This review summarizes recent data that highlight the importance of proper endplate function and the relationships between endplate dysfunction, adjacent disc degeneration, and axial low back pain. Recent findings Changes to endplate morphology and composition that impair its permeability associate with disc degeneration. Endplate damage also associates with disc degeneration, and the progression of degeneration may be accelerated and the chronicity of symptoms heightened when damage coincides with evidence of adjacent bone marrow lesions. Summary The endplate plays a key role in the development of disc degeneration and low back pain. Clarification of the mechanisms governing endplate degeneration and developments in clinical imaging that enable precise evaluation of endplate function and dysfunction will distinguish the correlative vs. causative nature of endplate damage and motivate new treatments that target pathologic endplate function.
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47
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Ruiz Wills C, Foata B, González Ballester MÁ, Karppinen J, Noailly J. Theoretical Explorations Generate New Hypotheses About the Role of the Cartilage Endplate in Early Intervertebral Disk Degeneration. Front Physiol 2018; 9:1210. [PMID: 30283342 PMCID: PMC6156535 DOI: 10.3389/fphys.2018.01210] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
Altered cell nutrition in the intervertebral disk (IVD) is considered a main cause for disk degeneration (DD). The cartilage endplate (CEP) provides a major path for the diffusion of nutrients from the peripheral vasculature to the IVD nucleus pulposus (NP). In DD, sclerosis of the adjacent bony endplate is suggested to be responsible for decreased diffusion and disk cell nutrition. Yet, experimental evidence does not support this hypothesis. Hence, we evaluated how moderate CEP composition changes related to tissue degeneration can affect disk nutrition and cell viability. A novel composition-based permeability formulation was developed for the CEP, calibrated, validated, and used in a mechano-transport finite element IVD model. Fixed solute concentrations were applied at the outer surface of the annulus and the CEP, and three cycles of daily mechanical load were simulated. The CEP model indicated that CEP permeability increases with the degeneration/aging of the tissue, in accordance with recent measurements reported in the literature. Additionally, our results showed that CEP degeneration might be responsible for mechanical load-induced NP dehydration, which locally affects oxygen and lactate levels, and reduced glucose concentration by 16% in the NP-annulus transition zone. Remarkably, CEP degeneration was a condition sine-qua-non to provoke cell starvation and death, while simulating the effect of extracellular matrix depletion in DD. This theoretical study cast doubts about the paradigm that CEP calcification is needed to provoke cell starvation, and suggests an alternative path for DD whereby the early degradation of the CEP plays a key role.
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Affiliation(s)
- Carlos Ruiz Wills
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Baptiste Foata
- Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Miguel Á González Ballester
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Jaro Karppinen
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.,Center for Life Course Health Research, Oulu University Hospital, Oulu, Finland.,Finnish Institute of Occupational Health, Oulu, Finland
| | - Jérôme Noailly
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
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48
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Bardonova LA, Sheikh O, Malova IO, Sorokovikov VA, Byvaltsev VA. ENERGY SUPPLY AND DEMAND IN THE INTERVERTEBRAL DISC. COLUNA/COLUMNA 2018. [DOI: 10.1590/s1808-185120181703193837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT The intervertebral disc (IVD) is one of the parts of the body most commonly affected by disease, and it is only recently that we have come closer to understanding the reasons for its degeneration, in which nutrient supply plays a crucial role. In this literature review, we discuss the basic principles and characteristics of energy supply and demand to the IVD. Specifically, we review how different metabolites influence IVD cell activity, the effects of mechanical loading on IVD cell metabolism, and differences in energy metabolism of the annulus fibrous and nucleus pulposus cell phenotypes. Determining the factors that influence nutrient supply and demand in the IVD will enhance our understanding of the IVD pathology, and help to elucidate new therapeutic targets for IVD degeneration treatment.
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Berg-Johansen B, Han M, Fields AJ, Liebenberg EC, Lim BJ, Larson PE, Gunduz-Demir C, Kazakia GJ, Krug R, Lotz JC. Cartilage Endplate Thickness Variation Measured by Ultrashort Echo-Time MRI Is Associated With Adjacent Disc Degeneration. Spine (Phila Pa 1976) 2018; 43:E592-E600. [PMID: 28984733 PMCID: PMC5882595 DOI: 10.1097/brs.0000000000002432] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A magnetic resonance imaging study of human cadaver spines. OBJECTIVE To investigate associations between cartilage endplate (CEP) thickness and disc degeneration. SUMMARY OF BACKGROUND DATA Damage to the CEP is associated with spinal injury and back pain. However, CEP morphology and its association with disc degeneration have not been well characterized. METHODS Ten lumbar motion segments with varying degrees of disc degeneration were harvested from six cadaveric spines and scanned with magnetic resonance imaging in the sagittal plane using a T2-weighted two-dimensional (2D) sequence, a three-dimensional (3D) ultrashort echo-time (UTE) imaging sequence, and a 3D T1ρ mapping sequence. CEP thicknesses were calculated from 3D UTE image data using a custom, automated algorithm, and these values were validated against histology measurements. Pfirrmann grades and T1ρ values in the disc were assessed and correlated with CEP thickness. RESULTS The mean CEP thickness calculated from UTE images was 0.74 ± 0.04 mm. Statistical comparisons between histology and UTE-derived measurements of CEP thickness showed significant agreement, with the mean difference not significantly different from zero (P = 0.32). Within-disc variation of T1ρ (standard deviation) was significantly lower for Pfirrmann grade 4 than Pfirrmann grade 3 (P < 0.05). Within-disc variation of T1ρ and adjacent CEP thickness heterogeneity (coefficient of variation) had a significant negative correlation (r = -0.65, P = 0.04). The standard deviation of T1ρand the mean CEP thickness showed a moderate positive correlation (r = 0.40, P = 0.26). CONCLUSION This study demonstrates that quantitative measurements of CEP thickness measured from UTE magnetic resonance imaging are associated with disc degeneration. Our results suggest that variability in CEP thickness and T1ρ, rather than their mean values, may serve as valuable diagnostic markers for disc degeneration. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Britta Berg-Johansen
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
- Department of Bioengineering, UC Berkeley/UCSF Joint Program in Bioengineering, Berkeley, CA
| | - Misung Han
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | - Aaron J Fields
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
| | - Ellen C Liebenberg
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
| | - Brandon J Lim
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
| | - Peder Ez Larson
- Department of Bioengineering, UC Berkeley/UCSF Joint Program in Bioengineering, Berkeley, CA
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | - Cigdem Gunduz-Demir
- Department of Computer Engineering, Bilkent University, Ankara, Turkey
- Neuroscience Graduate Program, Bilkent University, Ankara, Turkey
| | - Galateia J Kazakia
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | - Roland Krug
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | - Jeffrey C Lotz
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
- Department of Bioengineering, UC Berkeley/UCSF Joint Program in Bioengineering, Berkeley, CA
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50
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Lin X, Chen J, Qiu P, Zhang Q, Wang S, Su M, Chen Y, Jin K, Qin A, Fan S, Chen P, Zhao X. Biphasic hierarchical extracellular matrix scaffold for osteochondral defect regeneration. Osteoarthritis Cartilage 2018; 26:433-444. [PMID: 29233641 DOI: 10.1016/j.joca.2017.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 11/25/2017] [Accepted: 12/04/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the effect of decellularized osteochondral extracellular matrix (ECM) scaffold for osteochondral defect regeneration. DESIGN We compared the histological features and microstructure of degenerated cartilage to normal articular cartilage. We also generated and evaluated osteochondral ECM scaffolds through decellularization technology. Then scaffolds were implanted to osteochondral defect in rabbit model. After 12 weeks surgery, regeneration tissues were analyzed by histology, immunohistochemistry evaluation. And possible mechanisms of angiogenesis and cell migration were explored. RESULTS We demonstrated decreased cell numbers, formation of fibrous cartilage, lost microstructure and worse permeability in degenerated cartilage compared to normal cartilage. We also generated an osteochondral ECM scaffold with a hierarchical structure that exhibited low immunogenicity, high bioactivity, and well biocompatibility. We found that the ECM scaffold promoted tissue regeneration in osteochondral defects, which was dependent on the scaffold constituents and stratified three-dimensional microstructure as well as on its ability to inhibit angiogenesis and stimulate cell migration. CONCLUSIONS Our findings demonstrated that the biphasic hierarchical ECM scaffold represents a novel and effective biomaterial that can be used in the treatment of osteochondral defect.
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Affiliation(s)
- X Lin
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - J Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - P Qiu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - Q Zhang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - S Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - M Su
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - Y Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China
| | - K Jin
- Department of Pathophysiology, Wenzhou Medical University, Wenzhou, China
| | - A Qin
- Department of Orthopedics, Shanghai Key Laboratory of Orthopedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - S Fan
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China.
| | - P Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China.
| | - X Zhao
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, China.
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