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Hu S, Zhu M, Xing H, Xue Y, Li J, Wang Z, Zhu Z, Fang M, Li Z, Xu J, He Y, Zhang N. Thread-structural microneedles loaded with engineered exosomes for annulus fibrosus repair by regulating mitophagy recovery and extracellular matrix homeostasis. Bioact Mater 2024; 37:1-13. [PMID: 38515611 PMCID: PMC10951295 DOI: 10.1016/j.bioactmat.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/09/2024] [Accepted: 03/04/2024] [Indexed: 03/23/2024] Open
Abstract
Low back pain is among the most grave public health concerns worldwide and the major clinical manifestation of intervertebral disc degeneration (IVDD). The destruction of annulus fibrosus (AF) is the primary cause of IVDD. A sustainable and stable treatment system for IVDD is lacking because of the special organizational structure and low nutrient supply of AF. We here found that IVDD results in the impaired mitochondrial function of AF tissue, and mitochondrial autophagy (mitophagy) plays a protective role in this process. We therefore reported a thread-structural microneedle (T-MN) matching the ring structure of AF. Based on the adsorption effect of laminin, our T-MN could load with bone marrow mesenchymal stem cell-derived exosomes to envelope the regulating mitophagy microRNA (miRNA 378), named as T-MN@EXO@miR-378. In general, we offered in situ locking in the defect site of AF to prevent nucleus pulposus leakage and promoted AF repair. The design of the thread structure was aimed at bionically matching the layered AF structure, thereby providing stronger adhesion. The T-MN@EXO@miR-378 effectively attached to AF and slowly released therapeutic engineered exosomes, and prevented IVDD progression by restoring mitophagy, promoting AF cell proliferation and migration, and inhibiting the pathological remodeling of the extracellular matrix. This functional system can be used as an excellent tool for sustained drug release and has a certain prospect in substituting the conventional treatment of IVDD.
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Affiliation(s)
- Shaojun Hu
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Meng Zhu
- State Key Laboratory of Fluid Power and Mechatronic Systems, College of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, PR China
| | - Hongyuan Xing
- Department of Orthopaedics, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, PR China
| | - Yucheng Xue
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Jun Li
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Zhan Wang
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Zhou Zhu
- State Key Laboratory of Fluid Power and Mechatronic Systems, College of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, PR China
| | - Miaojie Fang
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Zilong Li
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Jianbin Xu
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
| | - Yong He
- State Key Laboratory of Fluid Power and Mechatronic Systems, College of Mechanical Engineering, Zhejiang University, Hangzhou, 310027, PR China
| | - Ning Zhang
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou City, Zhejiang Province, PR China
- Orthopedics Research Institute of Zhejiang University, Hangzhou City, Zhejiang Province, PR China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou City, Zhejiang Province, PR China
- Clinical Research Center of Motor System Disease of Zhejiang Province, PR China
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Wei Z, Ye H, Li Y, Li X, Liu Y, Chen Y, Yu J, Wang J, Ye X. Mechanically tough, adhesive, self-healing hydrogel promotes annulus fibrosus repair via autologous cell recruitment and microenvironment regulation. Acta Biomater 2024; 178:50-67. [PMID: 38382832 DOI: 10.1016/j.actbio.2024.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/30/2024] [Accepted: 02/13/2024] [Indexed: 02/23/2024]
Abstract
Annulus fibrosus (AF) defect is an important cause of disc re-herniation after discectomy. The self-regeneration ability of the AF is limited, and AF repair is always hindered by the inflammatory microenvironment after injury. Hydrogels represent one of the most promising materials for AF tissue engineering strategies. However, currently available commercial hydrogels cannot withstand the harsh mechanical load within intervertebral disc. In the present study, an innovative triple cross-linked oxidized hyaluronic acid (OHA)-dopamine (DA)- polyacrylamide (PAM) composite hydrogel, modified with collagen mimetic peptide (CMP) and supplied with transforming growth factor beta 1 (TGF-β1) (OHA-DA-PAM/CMP/TGF-β1 hydrogel) was developed for AF regeneration. The hydrogel exhibited robust mechanical strength, strong bioadhesion, and significant self-healing capabilities. Modified with collagen mimetic peptide, the hydrogel exhibited extracellular-matrix-mimicking properties and sustained the AF cell phenotype. The sustained release of TGF-β1 from the hydrogel was pivotal in recruiting AF cells and promoting extracellular matrix production. Furthermore, the composite hydrogel attenuated LPS-induced inflammatory response and promote ECM synthesis in AF cells via suppressing NFκB/NLRP3 pathway. In vivo, the composite hydrogel successfully sealed AF defects and alleviated intervertebral disk degeneration in a rat tail AF defect model. Histological evaluation showed that the hydrogel integrated well with host tissue and facilitated AF repair. The strategy of recruiting endogenous cells and providing an extracellular-matrix-mimicking and anti-inflammatory microenvironment using the mechanically tough composite OHA-DA-PAM/CMP/TGF-β1 hydrogel may be applicable for AF defect repair in the clinic. STATEMENT OF SIGNIFICANCE: Annulus fibrosus (AF) repair is challenging due to its limited self-regenerative capacity and post-injury inflammation. In this study, a mechanically tough and highly bioadhesive triple cross-linked composite hydrogel, modified with collagen mimetic peptide (CMP) and supplemented with transforming growth factor beta 1 (TGF-β1), was developed to facilitate AF regeneration. The sustained release of TGF-β1 enhanced AF cell recruitment, while both TGF-β1 and CMP could modulate the microenvironment to promote AF cell proliferation and ECM synthesis. In vivo, this composite hydrogel effectively promoted the AF repair and mitigated the intervertebral disc degeneration. This research indicates the clinical potential of the OHA-DA-PAM/CMP/TGF-β1 composite hydrogel for repairing AF defects.
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Affiliation(s)
- Zhenyuan Wei
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Department of Orthopaedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Han Ye
- Department of Ophthalmology and Vision Science, Shanghai Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
| | - Yucai Li
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Department of Orthopaedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Xiaoxiao Li
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Yi Liu
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Department of Orthopaedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Yujie Chen
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China
| | - Jiangming Yu
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Department of Orthopaedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China.
| | - Jielin Wang
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China.
| | - Xiaojian Ye
- Laboratory of Key Technology and Materials in Minimally Invasive Spine Surgery, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China; Center for Spinal Minimally Invasive Research, Shanghai Jiao Tong University, Shanghai 200336, China; Department of Orthopaedics, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200336, China.
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Xi J, Wang X, Li X, Wu C, Zhang T, Lu Q. Analysis of the clinical efficacy of visualization of percutaneous endoscopic lumbar discectomy combined with annulus fibrosus suture in lumbar disc herniation. Neurosurg Rev 2024; 47:54. [PMID: 38240919 PMCID: PMC10799126 DOI: 10.1007/s10143-023-02276-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/15/2023] [Accepted: 12/31/2023] [Indexed: 01/22/2024]
Abstract
The objective of this study is to compare the clinical effectiveness of visualization of percutaneous endoscopic lumbar discectomy (VPELD) combined with annulus fibrosus suture technique and simple percutaneous endoscopic lumbar discectomy (PELD) technique in the treatment of lumbar disc herniation. A retrospective analysis was conducted on 106 cases of lumbar disc herniation treated with foraminoscopic technique at our hospital from January 2020 to February 2022. Among them, 33 cases were treated with VPELD combined with annulus fibrosus suture in group A, and 73 cases were treated with PELD in group B. The preoperative and postoperative visual analogue scale (VAS), functional index (Oswestry Disability Index, ODI), healing of the annulus fibrosus, intervertebral space height, and postoperative recurrence were recorded and compared between the two groups. All patients underwent preoperative and postoperative MRI examinations, and the average follow-up period was 12 ± 2 months. Both groups showed significant improvements in postoperative VAS and ODI scores compared to the preoperative scores (P < 0.05), with no statistically significant difference between the groups during the same period (P > 0.05). There was no significant decrease in intervertebral space between the two groups after surgery (P > 0.05). Group A showed significantly lower postoperative recurrence rate and better annulus fibrosus healing compared to group B (P < 0.05). The VPELD combined with annulus fibrosus suture technique is a safe, feasible, and effective procedure for the treatment of lumbar disc herniation. When the indications are strictly adhered to, this technique can effectively reduce the postoperative recurrence rate and reoperation rate. It offers satisfactory clinical efficacy and can be considered as an alternative treatment option for eligible patients.
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Affiliation(s)
- Jintao Xi
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China
| | - Xiaozhen Wang
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China
| | - Xugui Li
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China
| | - Congjun Wu
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China
| | - Tonghui Zhang
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China
| | - Qilin Lu
- Department of Orthopedics, The Affiliated Hospital of Wuhan Sports University, Wuhan, 430079, Hubei, China.
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Leão Monteiro R. Future of low back pain: unravelling IVD components and MSCs' potential. Cell Regen 2024; 13:1. [PMID: 38227139 DOI: 10.1186/s13619-023-00184-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/27/2023] [Indexed: 01/17/2024]
Abstract
Low back pain (LBP) mainly emerges from intervertebral disc (IVD) degeneration. However, the failing mechanism of IVD ́s components, like the annulus fibrosus (AF) and nucleus pulposus (NP), leading to IVD degeneration/herniation is still poorly understood. Moreover, the specific role of cellular populations and molecular pathways involved in the inflammatory process associated with IVD herniation remains to be highlighted. The limited knowledge of inflammation associated with the initial steps of herniation and the lack of suitable models to mimic human IVD ́s complexity are some of the reasons for that. It has become essential to enhance the knowledge of cellular and molecular key players for AF and NP cells during inflammatory-driven degeneration. Due to unique properties of immunomodulation and pluripotency, mesenchymal stem cells (MSCs) have attained diverse recognition in this field of bone and cartilage regeneration. MSCs therapy has been particularly valuable in facilitating repair of damaged tissues and may benefit in mitigating inflammation' degenerative events. Therefore, this review article conducts comprehensive research to further understand the intertwine between the mechanisms of action of IVD components and therapeutic potential of MSCs, exploring their characteristics, how to optimize their use and establish them safely in distinct settings for LPB treatment.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Skidanov A, Ashukina N, Maltseva V, Skidanov M, Danyshchuk Z, Radchenko V. The relationship between structural changes in paraspinal muscles and intervertebral disc and facet joint degeneration in the lumbar spine of rats. J Orthop Surg Res 2024; 19:58. [PMID: 38217024 PMCID: PMC10785363 DOI: 10.1186/s13018-024-04548-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/08/2024] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND Degenerative spine disease is one of the largest causes of disability worldwide and has a multifactorial aetiology. Determining the leading causes of this multifactorial disease could help create new treatment approaches. PURPOSE Study the impact of degenerative changes in the paraspinal muscles caused by local (prolonged compression) or systemic (high-fat diet) factors on the structure of the intervertebral discs (IVDs) and facet joints of the lumbar spine in rats. METHODS The study was conducted using two animal models to create degenerative changes in the paraspinal muscles of 10 white laboratory rats for 90 days and five control rats: 1) high-fat diet model (model 1) involved keeping the rats on a high calorie diet; 2) compression model (model 2) involved binding the paraspinal muscles from L2 to S1 using non-absorbable sutures. Histological analysis for the facet joints and IVDs of rats (at the L1-L4 level) with semi-quantitative analysis of the structure conducted used by degeneration grading system for IVDs and cartilage degeneration score (OARSI) for facet joint. RESULTS In both models, 90 days after the experiment, the degenerative changes observed in the rats' IVDs were more severe in the annulus fibrosus than in the nucleus pulposus. The height of the IVD in model 1 did not differ from the control group, but in the model 2 was 1.3 times greater (p < 0.001) compared with control. Degenerative changes in the IVD were scored out 5.3 ± 1.7 in model 1 and 5.32 ± 2.1 in model 2 of a possible 16. The height of the articular cartilage of the facet joints was smaller by 1.5 times (p < 0.001) and 1.4 times (p < 0.001) in model 1 and model 2, respectively, compared to the control. Degenerative changes of facet joint were scored out 3.7 ± 0.6 in model 1 and 3.8 ± 0.6 in model 2 of five points according to the cartilage degeneration score. CONCLUSIONS It was determined that rats who had structural changes in the lumbar paraspinal muscles as a result of being kept on a high-fat diet or subjected to prolonged compression for 90 days, showed degenerative changes in intervertebral discs and osteoarthritis in facet joints of lumbar spine.
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Affiliation(s)
- Artem Skidanov
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine
| | - Nataliya Ashukina
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine
| | - Valentyna Maltseva
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine.
| | - Mykyta Skidanov
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine
| | - Zinaida Danyshchuk
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine
| | - Volodymyr Radchenko
- Laboratory of Connective Tissue Morphology, Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, 80 Pushkinska St., Kharkiv, 61024, Ukraine
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Zhu P, Wu X, Ni L, Chen K, Dong Z, Du J, Kong F, Mao Y, Tao H, Chu M, Mao H, Yang H, Liu Q, Gan M, Geng D. Inhibition of PP2A ameliorates intervertebral disc degeneration by reducing annulus fibrosus cells apoptosis via p38/MAPK signal pathway. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166888. [PMID: 37722489 DOI: 10.1016/j.bbadis.2023.166888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/05/2023] [Accepted: 09/12/2023] [Indexed: 09/20/2023]
Abstract
BACKGROUND Intervertebral disc degeneration (IVDD) is considered one of the main reasons for low back pain (LBP). To date, the specific pathology of IVDD remains unclear. The annulus fibrosus (AF) is an important part of the intervertebral disc, and AF cell oxidative stress, apoptosis plays a vital role in disc degeneration. Protein phosphatase 2 A (PP2A), a serine/threonine phosphatase, has regulatory functions in various processes, including apoptosis and autophagy. However, thus far, the effect of PP2A on IVDD is not clear. METHODS AF cells derived from caudal intervertebral discs in SD rats were used to analyze the levels of oxidative stress, apoptosis and degeneration as well as PP2A expression. A PP2A agonist (FTY720), inhibitor (microcystin-LR) and siRNA (si-PPP2CA) were employed in IVDD induced by H2O2 to investigate the levels of apoptosis and degeneration. The p38/MAPK signal pathways were evaluated, and a p38 inhibitor (SB203580) and ERK inhibitor (U0126) were added for verification. Finally, FTY720 and microcystin-LR were administered to IVDD rats to assess the effects on levels of apoptosis and degeneration and the relief of IVDD. RESULTS The expression of PP2A was increased in rat AF cells after H2O2 intervention. The levels of apoptosis and degeneration were higher with upregulation of PP2A but were significantly reduced after inhibition of PP2A. The PP2A inhibitor relieved cell apoptosis and degeneration by downregulating the p38/MAPK pathway. In vivo, the knockdown of PP2A resulted in a more complete morphology of discs and less apoptotic and degenerative expression. CONCLUSIONS This study suggests that the downregulation of PP2 A could reduce AF cell apoptosis and degeneration via the p38/MAPK pathway. It also revealed that the inhibition of PP2 A is expected to be a therapeutic target for IVDD.
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Affiliation(s)
- Pengfei Zhu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Xiexing Wu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Li Ni
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Kai Chen
- Department of Orthopedics, Hai'an People's Hospital, Hai'an 226600, Jiangsu, China
| | - Zhongchen Dong
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Jiacheng Du
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Fanchen Kong
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Yubo Mao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Huaqiang Tao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Miao Chu
- Department of Orthopedics, Yixing People's Hospital, Yixing 214200, Jiangsu, China
| | - Haiqin Mao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China
| | - Huilin Yang
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China.
| | - Qinbai Liu
- Department of Orthopaedics, Lianshui People's Hospital of Kangda College Affiliated to Nanjing Medical University, Huai'an 223001, Jiangsu, China; Department of Orthopaedics, Nanjing First Hospital, Nanjing Medical University, Nanjing 210000, Jiangsu, China.
| | - Minfeng Gan
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China.
| | - Dechun Geng
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China.
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Zhou D, Liu H, Zheng Z, Wu D. Design principles in mechanically adaptable biomaterials for repairing annulus fibrosus rupture: A review. Bioact Mater 2024; 31:422-439. [PMID: 37692911 PMCID: PMC10485601 DOI: 10.1016/j.bioactmat.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/25/2023] [Accepted: 08/12/2023] [Indexed: 09/12/2023] Open
Abstract
Annulus fibrosus (AF) plays a crucial role in the biomechanical loading of intervertebral disc (IVD). AF is difficult to self-heal when the annulus tears develop, because AF has a unique intricate structure and biologic milieu in vivo. Tissue engineering is promising for repairing AF rupture, but construction of suitable mechanical matching devices or scaffolds is still a grand challenge. To deeply know the varied forces involved in the movement of the native annulus is highly beneficial for designing biomimetic scaffolds to recreate the AF function. In this review, we overview six freedom degrees of forces and adhesion strength on AF tissue. Then, we summarize the mechanical modalities to simulate related forces on AF and to assess the characteristics of biomaterials. We finally outline some current advanced techniques to develop mechanically adaptable biomaterials for AF rupture repair.
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Affiliation(s)
- Dan Zhou
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Hongmei Liu
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Zhaomin Zheng
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, China
- Pain Research Center, Sun Yat-Sen University, Guangzhou 510080, China
| | - Decheng Wu
- Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
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9
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Liu X, Zhao W, Hu M, Zhang Y, Wang J, Zhang L. Cadmium-induced annulus fibrosus cell senescence contributes to intervertebral disc degeneration via the JNK/p53 signaling pathway. Iran J Basic Med Sci 2024; 27:588-595. [PMID: 38629100 PMCID: PMC11017839 DOI: 10.22038/ijbms.2024.72312.15728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 12/18/2023] [Indexed: 04/19/2024]
Abstract
Objectives Investigating the impact of cadmium (Cd) on annulus fibrosus (AF) cells and its potential mechanism was the purpose of the current study. Materials and Methods Cd was cultivated in different concentrations (0, 1, 5, 10, and 20 μM) on AF cells and the potential effects of the metal were assessed. Using the CCK-8 method, cell viability and proliferation were identified. Using transcriptome analysis, the annulus fibrosus cells were sequenced both with and without cadmium chloride. The EdU method was used to determine the rate of cell proliferation; senescence-associated β-galactosidase (SA-β-Gal) staining was used to determine the number of positive cells; and western blot, RT-PCR, and immunofluorescence were used to determine the protein and mRNA expression of senescence-associated proteins (p16, p21, and p53) and c-Jun N-terminal kinase (JNK). Results According to the findings, Cd has the ability to increase the production of senescence-associated genes (p16 and p21) and senescence-associated secreted phenotype (SASP), which includes IL-1β and IL-6. Through the JNK/p53 signal pathway, Cd exposure simultaneously accelerated AF cell senescence and promoted SASP. Following JNK inhibitor (SP600125) treatment, the expression of p53, JNK, and senescence-associated indices were all down-regulated. Conclusion By activating the JNK/p53 signaling pathway, Cd can induce oxidative stress damage and AF cell senescence. These findings could provide a new approach for treating and preventing intervertebral disc degeneration (IVDD) caused by Cd exposure.
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Affiliation(s)
- Xin Liu
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou 225001, Jiangsu, China
- These authors contributed equally to this work
| | - Wenjie Zhao
- Department of Orthopedics, Dalian Medical University, Dalian 116000, Liaoning, China
- These authors contributed equally to this work
| | - Man Hu
- Department of Orthopedics, Dalian Medical University, Dalian 116000, Liaoning, China
- These authors contributed equally to this work
| | - Yu Zhang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou 225001, Jiangsu, China
| | - Jingcheng Wang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou 225001, Jiangsu, China
| | - Liang Zhang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou 225001, Jiangsu, China
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Chow N, Gregory DE. The effect of intervertebral disc damage on the mechanical strength of the annulus fibrosus in the adjacent segment. Spine J 2023; 23:1935-1940. [PMID: 37487934 DOI: 10.1016/j.spinee.2023.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/03/2023] [Accepted: 07/16/2023] [Indexed: 07/26/2023]
Abstract
BACKGROUND CONTEXT A herniated intervertebral disc (IVD) is a common injury in the human population. Despite the injury being isolated to a singular IVD in the spine, it is important to look at the biomechanical effects that a damaged IVD has on the entire spine, specifically the IVD adjacent to the injury. PURPOSE This study examined the effects of a damaged IVD on the mechanical properties of the annulus fibrosus (AF) in the adjacent cranial IVD. STUDY DESIGN Basic science study using an in-vitro porcine model. METHODS Sixteen porcine cervical spines were used; specifically spinal levels C3/4/5 were assigned to one of two experimental groups: 1) a control group that was not subjected any injuries (n=8); 2) an experimental group that experienced an injury to the anterolateral part of the disc, reaching the nucleus pulposus but without affecting the posterior portion of the AF in the C4/5 functional spine unit (FSU) (n=8). Each specimen underwent a previously published precondition compression protocol of 300 N of compression for 15 minutes followed by a cyclical compression protocol of compression protocol of 0.5 Hz sinusoidal waveform at 300 to 1200 N for 2 hours (3600 cycles). Post compression, the C3/4 AF was dissected to obtain two multilayer samples (one anterior and one posterior) as well as a peel sample (from the posterolateral region). A tensile strength test was conducted to examine the strength of the interlamellar matrix (peel sample) and the overall strength of the AF (multilayer samples). RESULTS Significant results were found in the peel test samples. Specifically, experimental specimens were less stiff compared than control specimens (p<.01). In addition, experimental specimens also had a lower average strength then control specimens (p<.01). This reduction in both interlamellar strength and stiffness increases the risk of delamination in the experimental samples. In contrast, there were no differences found between the two groups when examining the AF as a whole through the multilayer tests (p>.05). CONCLUSIONS It appears that a damaged IVD impacts the biomechanics of the spine and specifically the mechanical properties of the adjacent IVD. Specifically, the observed weakening of the interlamellar matrix in these adjacent IVDs may predispose it to delamination and subsequently degeneration or herniation. CLINICAL SIGNIFICANCE These findings may help clinicians when treating patients who have experienced a disc herniation or severe degeneration, as they may potentially experience accelerated adjacent disc degeneration.
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Affiliation(s)
- Noah Chow
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, Ontario, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Diane E Gregory
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, Ontario, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, Ontario, Canada.
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11
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Hu X, Tian X, Yang C, Ling F, Liu H, Zhu X, Pei M, Yang H, Liu T, Xu Y, He F. Melatonin-loaded self-healing hydrogel targets mitochondrial energy metabolism and promotes annulus fibrosus regeneration. Mater Today Bio 2023; 23:100811. [PMID: 37810753 PMCID: PMC10550778 DOI: 10.1016/j.mtbio.2023.100811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/21/2023] [Accepted: 09/21/2023] [Indexed: 10/10/2023] Open
Abstract
Intervertebral disc (IVD) herniation is a major cause of chronic low back pain and disability. The current nucleus pulposus (NP) discectomy effectively relieves pain symptoms, but the annulus fibrosus (AF) defects are left unrepaired. Tissue engineering approaches show promise in treating AF injury and IVD degeneration; however, the presence of an inflammatory milieu at the injury site hinders the mitochondrial energy metabolism of AF cells, resulting in a lack of AF regeneration. In this study, we fabricated a dynamic self-healing hydrogel loaded with melatonin (an endocrine hormone well-known for its antioxidant and anti-inflammatory properties) and investigate whether melatonin-loaded hydrogel could promote AF defect repair by rescuing the matrix synthesis and energy metabolism of AF cells. The protective effects of melatonin on matrix components (e.g. type I and II collagen and aggrecan) in AF cells were observed in the presence of interleukin (IL)-1β. Additionally, melatonin was found to activate the nuclear factor erythroid 2-related factor signaling pathway, thereby safeguarding the mitochondrial function of AF cells from IL-1β, as evidenced by the increased level of adenosine triphosphate, mitochondrial membrane potential, and respiratory chain factor expression. The incorporation of melatonin into a self-healing hydrogel based on thiolated gelatin and β-cyclodextrin was proposed as a means of promoting AF regeneration. The successful implantation of melatonin-loaded hydrogel has been shown to facilitate in situ regeneration of AF tissue, thereby impeding IVD degeneration by preserving the hydration of nucleus pulposus in a rat box-cut IVD defect model. These findings offer compelling evidence that the development of a melatonin-loaded dynamic self-healing hydrogel can promote the mitochondrial functions of AF cells and represents a promising strategy for IVD regeneration.
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Affiliation(s)
- Xiayu Hu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
| | - Xin Tian
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
| | - Chunju Yang
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
- Suzhou Medical College of Soochow University, Suzhou, 215123, China
| | - Feng Ling
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
- Department of Orthopaedics,the Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou, 225300, China
| | - Hao Liu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
| | - Xuesong Zhu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
| | - Ming Pei
- Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics and Division of Exercise Physiology, West Virginia University, Morgantown, WV 26506, USA
| | - Huilin Yang
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
| | - Tao Liu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
| | - Yong Xu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
| | - Fan He
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou 215006, China
- Orthopaedic Institute, Suzhou Medical College, Soochow University, Suzhou 215000, China
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12
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Bhattacharya S, Dubey DK. A multiscale investigation into the role of collagen-hyaluronan interface shear on the mechanical behaviour of collagen fibers in annulus fibrosus - Molecular dynamics-cohesive finite element-based study. J Mech Behav Biomed Mater 2023; 147:106147. [PMID: 37812947 DOI: 10.1016/j.jmbbm.2023.106147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/30/2023] [Accepted: 09/23/2023] [Indexed: 10/11/2023]
Abstract
Multi-directional deformation exhibited by annulus fibrosus (AF) is contributed by chemo-mechanical interactions among its biomolecular constituents' collagen type I (COL-I), collagen type II (COL-II), proteoglycans (aggrecan and hyaluronan) and water. However, the nature and role of such interactions on AF mechanics are unclear. This work employs a molecular dynamics-cohesive finite element-based multiscale approach to investigate role of COL-I-COL-II interchanging distribution and water concentration (WC) variations from outer annulus (OA) to inner annulus (IA) on collagen-hyaluronan (COL-HYL) interface shear, and the mechanisms by which interface shear impacts fibril sliding during collagen fiber deformation. At first, COL-HYL interface atomistic models are constructed by interchanging COL-I with COL-II and increasing COL-II and WC from 0 to 75%, and 65%-75% respectively. Thereafter, a multiscale approach is employed to develop representative volume elements (RVEs) of collagen fibers by incorporating COL-HYL shear as traction-separation behaviour at fibril-hyaluronan contact. Results show that increasing COL-II and WC increases interface stiffness from 0.6 GPa/nm to 1.2 GPa/nm and reduces interface strength from 155 MPa to 58 MPa from OA to IA, contributed by local hydration alterations. A stiffer and weaker interface enhances fibril sliding with increased straining at the contact - thereby contributing to reduction in modulus from 298 MPa to 198 MPa from OA to IA. Such reduction further contributes to softer mechanical response towards IA, as reported by earlier studies. Presented multiscale analysis provides deeper understanding of hierarchical structure-mechanics relationships in AF and can further aid in developing better substitutes for AF repair.
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Affiliation(s)
- Shambo Bhattacharya
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, Haus Khas, New Delhi, 110016, India
| | - Devendra K Dubey
- Department of Mechanical Engineering, Indian Institute of Technology Delhi, Haus Khas, New Delhi, 110016, India.
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13
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Piao C, Le Floc'h S, Cañadas P, Wagner-Kocher C, Royer P. Fiber orientation and crimp level might control the auxetic effect of biological tissues. J Mech Behav Biomed Mater 2023; 147:106098. [PMID: 37689010 DOI: 10.1016/j.jmbbm.2023.106098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/26/2023] [Accepted: 08/28/2023] [Indexed: 09/11/2023]
Abstract
We propose an analytical micromechanical model for studying the lamellar-composite-like structure of fibrous soft tissue. The tissue under consideration is made up of several lamellae, and is designed to resemble the annulus fibrosus (AF) tissue or media layer of arterial tissue, for example. The collagen fibers are arranged in parallel in each lamella and the fiber orientation differs from one lamella to its neighbors. The parallel fibers in each lamella of AF tissue, for example, have been observed to have a crimped microstructure. The proposed model incorporates this quality, considering fiber waviness as a sinusoidal shape and taking into account the fiber dispersion in different layers, where both fiber and matrix are considered as solid phases. We find that collagen-fiber waviness and layer orientation have a significant influence on Poisson's ratio. The effective Poisson's ratio predicted by the proposed model demonstrates that the crimped collagen fiber microstructure might weaken the auxetic effect of fibrous soft tissue, which might explain why, as the literature suggests, the auxetic behavior is more difficult to observe than large Poisson's ratios. As opposed to the many studies that use the well-known hyperelastic fiber-based constitutive model, in which out-of-plane expansion is often observed, the present work explains the auxetic response found in modeling and in experimental data from the perspective of collagen fiber microstructure.
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Affiliation(s)
- C Piao
- LMGC, Univ. Montpellier, CNRS, Montpellier, France.
| | - S Le Floc'h
- LMGC, Univ. Montpellier, CNRS, Montpellier, France
| | - P Cañadas
- LMGC, Univ. Montpellier, CNRS, Montpellier, France
| | - C Wagner-Kocher
- LMGC, Univ. Montpellier, CNRS, Montpellier, France; LPMT, UHA, Mulhouse, France
| | - P Royer
- LMGC, Univ. Montpellier, CNRS, Montpellier, France
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14
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Zhou Z, Qin W, Zhang P, He J, Cheng Z, Gong Y, Zhu G, Liang D, Ren H, Jiang X, Sun Y. Potential molecular targets and drugs for basement membranes-related intervertebral disk degeneration through bioinformatics analysis and molecular docking. BMC Musculoskelet Disord 2023; 24:772. [PMID: 37784117 PMCID: PMC10544312 DOI: 10.1186/s12891-023-06891-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 09/16/2023] [Indexed: 10/04/2023] Open
Abstract
BACKGROUND Through bioinformatics analysis to identify the hub genes of Intervertebral disc degeneration (IVDD) associated with basement membranes (BMs) and find out the potential molecular targets and drugs for BMs-related annulus fibrosus (AF) degeneration based on bioinformatic analysis and molecular approach. METHODS Intervertebral disc degeneration (IVDD) related targets were obtained from GeneCards, DisGenet and OMIM databases. BMs related genes were obtained from Basement membraneBASE database. The intersection targets were identified and subjected to protein-to-protein interaction (PPI) construction via STRING. Hub genes were identified and conducted Gene ontology (GO) and pathway enrichment analysis through MCODE and Clue GO in Cytospace respectively. DSigDB database was retrieved to predict therapeutic drugs and molecular docking was performed through PyMOL, AutoDock 1.5.6 to verify the binding energy between the drug and the different expressed hub genes. Finally, GSE70362 from GEO database was obtained to verify the different expression and correlation of each hub gene for AF degeneration. RESULTS We identified 41 intersection genes between 3 disease targets databases and Basement membraneBASE database. PPI network revealed 25 hub genes and they were mainly enriched in GO terms relating to glycosaminoglycan catabolic process, the TGF-β signaling pathway. 4 core targets were found to be significant via comparison of microarray samples and they showed strong correlation. The molecular docking results showed that the core targets have strong binding energy with predicting drugs including chitosamine and retinoic acid. CONCLUSIONS In this study, we identified hub genes, pathways, potential targets, and drugs for treatment in BMs-related AF degeneration and IVDD.
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Affiliation(s)
- Zelin Zhou
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Weicheng Qin
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Peng Zhang
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Jiahui He
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Zhaojun Cheng
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Yan Gong
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Guangye Zhu
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Hui Ren
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Xiaobing Jiang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, P.R. China
| | - Yuping Sun
- Pingshan General Hospital, Southern Medical University, Shenzhen, Guangdong, P.R. China.
- Pingshan District People's Hospital of Shenzhen, Shenzhen, Guangdong, P.R. China.
- Rehabilitation Department, Pingshan District People's Hospital, Shenzhen, P.R. China.
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Zhou M, Archibeck ES, Feteih Y, Abubakr Y, O'Connell GD. Non-enzymatic glycation increases the failure risk of annulus fibrosus by predisposing the extrafibrillar matrix to greater stresses. Acta Biomater 2023; 168:223-234. [PMID: 37433360 DOI: 10.1016/j.actbio.2023.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/13/2023] [Accepted: 07/06/2023] [Indexed: 07/13/2023]
Abstract
Growing clinical evidence suggests a correlation between diabetes and more frequent and severe intervertebral disc failure, partially attributed to accelerated advanced glycation end-products (AGE) accumulation in the annulus fibrosus (AF) through non-enzymatic glycation. However, in vitro glycation (i.e., crosslinking) reportedly improved AF uniaxial tensile mechanical properties, contradicting clinical observations. Thus, this study used a combined experimental-computational approach to evaluate the effect of AGEs on anisotropic AF tensile mechanics, applying finite element models (FEMs) to complement experimental testing and examine difficult-to-measure subtissue-level mechanics. Methylglyoxal-based treatments were applied to induce three physiologically relevant AGE levels in vitro. Models incorporated crosslinks by adapting our previously validated structure-based FEM framework. Experimental results showed that a threefold increase in AGE content resulted in a ∼55% increase in AF circumferential-radial tensile modulus and failure stress and a 40% increase in radial failure stress. Failure strain was unaffected by non-enzymatic glycation. Adapted FEMs accurately predicted experimental AF mechanics with glycation. Model predictions showed that glycation increased stresses in the extrafibrillar matrix under physiologic deformations, which may increase tissue mechanical failure or trigger catabolic remodeling, providing insight into the relationship between AGE accumulation and increased tissue failure. Our findings also added to the existing literature regarding crosslinking structures, indicating that AGEs had a greater effect along the fiber direction, while interlamellar radial crosslinks were improbable in the AF. In summary, the combined approach presented a powerful tool for examining multiscale structure-function relationships with disease progression in fiber-reinforced soft tissues, which is essential for developing effective therapeutic measures. STATEMENT OF SIGNIFICANCE: Increasing clinical evidence correlates diabetes with premature intervertebral disc failure, likely due to advanced glycation end-products (AGE) accumulation in the annulus fibrosus (AF). However, in vitro glycation reportedly increases AF tensile stiffness and toughness, contradicting clinical observations. Using a combined experimental-computational approach, our work shows that increases in AF bulk tensile mechanical properties with glycation are achieved at the risk of exposing the extrafibrillar matrix to increased stresses under physiologic deformations, which may increase tissue mechanical failure or trigger catabolic remodeling. Computational results indicate that crosslinks along the fiber direction account for 90% of the increased tissue stiffness with glycation, adding to the existing literature. These findings provide insight into the multiscale structure-function relationship between AGE accumulation and tissue failure.
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Affiliation(s)
- Minhao Zhou
- Department of Mechanical Engineering, University of California, Berkeley, 2162 Etcheverry Hall, #1740, Berkeley, CA 94720-1740, USA
| | - Erin S Archibeck
- Department of Mechanical Engineering, University of California, Berkeley, 2162 Etcheverry Hall, #1740, Berkeley, CA 94720-1740, USA
| | - Yarah Feteih
- Department of Mechanical Engineering, University of California, Berkeley, 2162 Etcheverry Hall, #1740, Berkeley, CA 94720-1740, USA
| | - Yousuf Abubakr
- Department of Mechanical Engineering, University of California, Berkeley, 2162 Etcheverry Hall, #1740, Berkeley, CA 94720-1740, USA
| | - Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, 5122 Etcheverry Hall, #1740, Berkeley, CA 94720-1740, USA; Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, USA.
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Hu X, Wang Z, Zhang H, Cui P, Li Y, Chen X, Kong C, Wang W, Lu S. Single-cell sequencing: New insights for intervertebral disc degeneration. Biomed Pharmacother 2023; 165:115224. [PMID: 37516017 DOI: 10.1016/j.biopha.2023.115224] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/18/2023] [Accepted: 07/23/2023] [Indexed: 07/31/2023] Open
Abstract
Over the past decade, single-cell RNA sequencing (scRNA-seq) has revolutionized research on biological mechanisms of diseases. Moreover, this technique has been utilized to identify and characterize unique cell types and subpopulations, thereby illuminating cellular heterogeneity. The true value of scRNA-seq lies in its ability to detect transcriptional alterations or perturbed pathways within specific cell types under pathological conditions. In the context of intervertebral disc degeneration (IVDD), the pathophysiological foundation is largely rooted in inflammation. The primary target cells of IVDD are nucleus pulposus cells, annulus fibrosus cells, cartilage endplate cells, and macrophages. The advancements in scRNA-seq technology have triggered remarkable progress in IVDD treatment, leading to breakthroughs in the identification of cell subsets, functional analysis, novel therapeutic targets, and the differentiation and development of various cell types. This review is the first of its kind to introduce the application of scRNA-seq techniques in IVDD, with a focus on the most recent scRNA-seq studies that have defined the populations of various cell types and specific cell-cell interactions in IVDD. Furthermore, we highlight several promising future research directions for scRNA-seq in IVDD.
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Affiliation(s)
- Xinli Hu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Zheng Wang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Haojie Zhang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Peng Cui
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yongjin Li
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Xiaolong Chen
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Chao Kong
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Wei Wang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
| | - Shibao Lu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China; National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
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Ao X, Li Y, Jiang T, Li C, Lian Z, Wang L, Zhang Z, Huang M. Angiopoietin-2 Promotes Mechanical Stress-induced Extracellular Matrix Degradation in Annulus Fibrosus Via the HIF-1α/NF-κB Signaling Pathway. Orthop Surg 2023; 15:2410-2422. [PMID: 37475697 PMCID: PMC10475680 DOI: 10.1111/os.13797] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 07/22/2023] Open
Abstract
OBJECTIVE Mechanical stress is an important risk factor for intervertebral disc degeneration (IVDD). Angiopoietin-2 (ANG-2) is regulated by mechanical stress and is widely involved in the regulation of extracellular matrix metabolism. In addition, the signaling cascade between HIF-1α and NF-κB is critical in matrix degradation. This study aims to investigate the role and molecular mechanism of ANG-2 in regulating the degeneration of annulus fibrosus (AF) through the HIF-1α/NF-κB signaling pathway. METHODS The bipedal standing mice IVDD model was constructed, and histological experiments were used to evaluate the degree of IVDD and the expression of ANG-2 in the AF. Mouse primary AF cells were extracted in vitro and subjected to mechanical stretching experiments. Western blot assay was used to detect the effect of mechanical stress on ANG-2, and the role of the ANG-2-mediated HIF-1α/NF-κB pathway in matrix degradation. In addition, the effect of inhibiting ANG-2 expression by siRNA or monoclonal antibody on delaying IVDD was investigated at in vitro and in vivo levels. One-way ANOVA with the least significant difference method was used for pairwise comparison of the groups with homogeneous variance, and Dunnett's method was used to compare the groups with heterogeneous variance. RESULTS In IVDD, the expressions of catabolic biomarkers (mmp-13, ADAMTS-4) and ANG-2 were significantly increased in AF. In addition, p65 expression was increased while HIF-1α expression was significantly decreased. The results of western blot assay showed mechanical stress significantly up-regulated the expression of ANG-2 in AF cells, and promoted matrix degradation by regulating the activity of HIF-1α/NF-κB pathway. Exogenous addition of Bay117082 and CoCl2 inhibited matrix degradation caused by mechanical stress. Moreover, injection of neutralizing antibody or treatment with siRNA to inhibit the expression of ANG-2 improved the matrix metabolism of AF and inhibited IVDD progression by regulating the HIF-1α/NF-κB signaling pathway. CONCLUSION In IVDD, mechanical stress could regulate the HIF-1α/NF-κB signaling pathway and matrix degradation by mediating ANG-2 expression in AF degeneration.
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Affiliation(s)
- Xiang Ao
- Division of Spine Surgery, Department of OrthopaedicsNanfang Hospital of Southern Medical UniversityGuangzhouGuangdongChina
| | - Yuan Li
- Department of Spine Surgery, Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdongChina
- Academy of Orthopaedics·Guangdong ProvinceGuangzhouGuangdongChina
| | - Tao Jiang
- Division of Spine Surgery, Department of OrthopaedicsNanfang Hospital of Southern Medical UniversityGuangzhouGuangdongChina
| | - Chenglong Li
- Division of Spine Surgery, Department of OrthopaedicsNanfang Hospital of Southern Medical UniversityGuangzhouGuangdongChina
| | - Zhengnan Lian
- Department of Spine Surgery, Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdongChina
- Academy of Orthopaedics·Guangdong ProvinceGuangzhouGuangdongChina
| | - Liang Wang
- Department of Spine Surgery, Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdongChina
- Academy of Orthopaedics·Guangdong ProvinceGuangzhouGuangdongChina
| | - Zhongmin Zhang
- Division of Spine Surgery, Department of OrthopaedicsNanfang Hospital of Southern Medical UniversityGuangzhouGuangdongChina
| | - Minjun Huang
- Department of Spine Surgery, Center for Orthopedic SurgeryThe Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdongChina
- Academy of Orthopaedics·Guangdong ProvinceGuangzhouGuangdongChina
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18
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Sun Z, Mi C. On the identification of the ultra-structural organization of elastic fibers and their effects on the integrity of annulus fibrosus. J Biomech 2023; 157:111728. [PMID: 37499432 DOI: 10.1016/j.jbiomech.2023.111728] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/10/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
Due to the complicated structure of the elastic fiber network in annulus fibrosus, existing in-silico studies either simplified or just overlooked its distribution pattern. Nonetheless, experimental and simulation results have proven that elastic fibers are of great importance to maintaining the structural integrity of annulus fibrosus and therefore to ensuring the load-bearing ability of intervertebral discs. Such needs call for a fine model. This work aims at developing a biphasic annulus fibrosus model by incorporating the accurate distribution pattern of collagen and elastic fibers. Both the structural parameters and intrinsic mechanical parameters were successfully identified using single lamella and inter-lamella microscopy anatomy and micromechanical testing data. The proposed model was then used to implement finite element simulations on various anterior and posterolateral multi-lamellae annulus fibrosus specimens. In general, simulation results agree well with available experimental and simulation data. On this basis, the effects of elastic fibers on the integrity of annulus fibrosus were further investigated. It was found that elastic fibers significantly influence the free swelling, radial stretching and circumferential shear performances of annulus fibrosus. Nonetheless, no significant effects were found for the circumferential stretching capability. The proposed biphasic model considers for the first time the distribution characteristics of elastic fibers at two scales, including both the principal orientations of all fiber families and the detailed distribution pattern within each family. Better understandings on the functions of collagen and elastic fibers can therefore be realized. To further enhance its prediction capability, the current model can be extended in the future by taking the fiber-matrix interaction as well as progressive damages into consideration.
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Affiliation(s)
- Zhongwei Sun
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Changwen Mi
- Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China.
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19
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Tu Z, Han F, Zhu Z, Yu Q, Liu C, Bao Y, Li B, Zhou F. Sustained release of basic fibroblast growth factor in micro/nanofibrous scaffolds promotes annulus fibrosus regeneration. Acta Biomater 2023; 166:241-253. [PMID: 37230436 DOI: 10.1016/j.actbio.2023.05.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 05/14/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Tissue engineering has promising applications in the treatment of intervertebral disc degeneration (IDD). The annulus fibrosus (AF) is critical for maintaining the physiological function of the intervertebral disc (IVD), but the lack of vessels and nutrition in AF makes it difficult to repair. In this study, we used hyaluronan (HA) micro-sol electrospinning and collagen type I (Col-I) self-assembly techniques to fabricate layered biomimetic micro/nanofibrous scaffolds, which released basic fibroblast growth factor (bFGF) to promote AF repair and regeneration after discectomy and endoscopic transforaminal discectomy. The bFGF enveloped in the core of the poly-L-lactic-acid (PLLA) core-shell structure was released in a sustained manner and promoted the adhesion and proliferation of AF cells (AFCs). Col-I could self-assemble on the shell of the PLLA core-shell scaffold to mimic the extracellular matrix (ECM) microenvironment, providing structural and biochemical cues for the regeneration of AF tissue. The in vivo studies showed that the micro/nanofibrous scaffolds promoted the repair of AF defects by simulating the microstructure of native AF tissue and inducing endogenous regeneration mechanism. Taken together, the biomimetic micro/nanofibrous scaffolds have clinical potential for the treatment of AF defects caused by IDD. STATEMENT OF SIGNIFICANCE: The annulus fibrosus (AF) is essential for the intervertebral disc (IVD) physiological function, yet it lacks vascularity and nutrition, making repair difficult. Micro-sol electrospinning technology and collagen type I (Col-I) self-assembly technique were combined in this study to create a layered biomimetic micro/nanofibrous scaffold that releases basic fibroblast growth factor (bFGF) to promote AF repair and regeneration. Col-I could mimic the extracellular matrix (ECM) microenvironment, in vivo, offering structural and biochemical cues for AF tissue regeneration. This research indicates that micro/nanofibrous scaffolds have clinical potential for treating AF deficits induced by IDD.
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Affiliation(s)
- Zhengdong Tu
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Feng Han
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Zhuang Zhu
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Qifan Yu
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Changjiang Liu
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Yu Bao
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Bin Li
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China.
| | - Feng Zhou
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, School of Biology & Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China.
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20
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Wang Z, Jin X, Zhang B, Kong J, Deng R, Wu K, Xie L, Liu X, Kang R. Stress stimulation maintaining by genipin crosslinked hydrogel promotes annulus fibrosus healing. J Orthop Translat 2023; 40:104-115. [PMID: 37457311 PMCID: PMC10338907 DOI: 10.1016/j.jot.2023.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/20/2023] [Accepted: 05/30/2023] [Indexed: 07/18/2023] Open
Abstract
Objective To explore the repair effect of tissue engineering for annulus fibrosus (AF) injury in stress-stimulation environment. Methods Non-adhesive fibrinogen (Fib) representing the repair with non-stress stimulation and adhesive hydrogel of fibrinogen, thrombin and genipin mixture (Fib-T-G) representing the repair with stress stimulation were prepared to repair the AF lesion. The relationship between adhesion and stress stimulation was studied in rheological measurements, tension tests and atomic force microscopy (AFM) experiments. The repair effect of stress stimulation was studied in designed acellular AF scaffold models with fissures and defects. The models were repaired by the two different hydrogels, then implanted subcutaneously and cultured for 21 d in rats. Histology and qPCR of COL1A1, COL2A1, aggrecan, RhoA, and ROCK of the tissue engineering of the interface were evaluated afterward. Moreover, the repair effect was also studied in an AF fissure model in caudal disc of rats by the two different hydrogels. Discs were harvested after 21 d, and the disc degeneration score and AF healing quality were evaluated by histology. Result In interfacial stress experiment, Fib-T-G hydrogel showed greater viscosity than Fib hydrogel (24.67 ± 1.007 vs 459333 ± 169205 mPa s). Representative force-displacement and sample modulus for each group demonstrate that Fib-T-G group significantly increased the interfacial stress level and enhanced the modulus of samples, compared with Fib group (P < 0.01). The Fib-T-G group could better bond the interface to resist the loading strain force with the broken point at 1.11 ± 0.10 N compared to the Fib group at 0.12 ± 0.08 N (P < 0.01). Focusing on the interfacial healing in acellular AF scaffold model, compared with Fib + MSCs group, the fissure and defect were connected closely in Fib-T-G + MSCs group (P < 0.01). Relative higher gene expression of COL2A1 and RhoA in Fib-T-G + MSCs group than Fib + MSCs group in AF fissure and AF defect model (P < 0.05). The immunohistochemistry staining showed more positive staining of COL2A1 and RhoA in Fib-T-G + MSCs group than in Fib + MSCs group in both AF fissure and AF defect models. The degree of disc degeneration was more severe in Fib + MSCs group than Fib-T-G + MSCs group in vivo experiment (11.80 ± 1.11 vs 7.00 ± 1.76, P < 0.01). The dorsal AF defect in Fib-T-G + MSCs group (0.02 ± 0.01 mm2) was significantly smaller than that (0.13 ± 0.05 mm2) in Fib + MSCs group (P < 0.05). Immunohistochemical staining showed more positive staining of COL2A1 and Aggrecan in Fib-T-G + MSCs group than in Fib + MSCs group. Conclusion Genipin crosslinked hydrogel can bond the interface of AF lesions and transfer strain force. Stress stimulation maintained by adhesive hydrogel promotes AF healing. The translational potential of this article We believe the effect of stress stimulation could be concluded through this study and provides more ideals in mechanical effects for further research, which is a key technique for repairing intervertebral disc in clinic. The adhesive hydrogel of Fib-T-G+MSCs has low toxicity and helps bond the interface of AF lesion and transfer strain force, having great potential in the repair of AF lesion.
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Affiliation(s)
- Zihan Wang
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Xiaoyu Jin
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Botao Zhang
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Jiaxin Kong
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Rongrong Deng
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Ke Wu
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Lin Xie
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Xin Liu
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
| | - Ran Kang
- The Third Clinical Medical College, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
- Department of Orthopedics, Nanjing Lishui Hospital of Traditional Chinese Medicine, Nanjing, Jiangsu Province, 210028, PR China
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21
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Ma J, Häne S, Eglauf J, Pfannkuche J, Soubrier A, Li Z, Peroglio M, Hoppe S, Benneker L, Lang G, Wangler S, Alini M, Creemers LB, Grad S, Häckel S. Celecoxib alleviates nociceptor sensitization mediated by interleukin-1beta-primed annulus fibrosus cells. Eur Spine J 2023:10.1007/s00586-023-07672-x. [PMID: 37071156 DOI: 10.1007/s00586-023-07672-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/15/2023] [Accepted: 03/18/2023] [Indexed: 04/19/2023]
Abstract
PURPOSE This study aims to analyze the effect of pro-inflammatory cytokine-stimulated human annulus fibrosus cells (hAFCs) on the sensitization of dorsal root ganglion (DRG) cells. We further hypothesized that celecoxib (cxb) could inhibit hAFCs-induced DRG sensitization. METHODS hAFCs from spinal trauma patients were stimulated with TNF-α or IL-1β. Cxb was added on day 2. On day 4, the expression of pro-inflammatory and neurotrophic genes was evaluated using RT-qPCR. Levels of prostaglandin E2 (PGE-2), IL-8, and IL-6 were measured in the conditioned medium (CM) using ELISA. hAFCs CM was then applied to stimulate the DRG cell line (ND7/23) for 6 days. Then, calcium imaging (Fluo4) was performed to evaluate DRG cell sensitization. Both spontaneous and bradykinin-stimulated (0.5 μM) calcium responses were analyzed. The effects on primary bovine DRG cell culture were performed in parallel to the DRG cell line model. RESULTS IL-1ß stimulation significantly enhanced the release of PGE-2 in hAFCs CM, while this increase was completely suppressed by 10 µM cxb. hAFCs revealed elevated IL-6 and IL-8 release following TNF-α and IL-1β treatment, though cxb did not alter this. The effect of hAFCs CM on DRG cell sensitization was influenced by adding cxb to hAFCs; both the DRG cell line and primary bovine DRG nociceptors showed a lower sensitivity to bradykinin stimulation. CONCLUSION Cxb can inhibit PGE-2 production in hAFCs in an IL-1β-induced pro-inflammatory in vitro environment. The cxb applied to the hAFCs also reduces the sensitization of DRG nociceptors that are stimulated by the hAFCs CM.
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Affiliation(s)
- Junxuan Ma
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | - Surya Häne
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
- ETH Zurich, Zurich, Switzerland
| | - Janick Eglauf
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
- ETH Zurich, Zurich, Switzerland
| | - Judith Pfannkuche
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | - Astrid Soubrier
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | - Zhen Li
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | | | - Sven Hoppe
- Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Lorin Benneker
- Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
- Spine Surgery, Sonnenhof Spital, Buchserstrasse 30, 3006, Bern, Switzerland
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center-Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Sebastian Wangler
- Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Mauro Alini
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | - Laura B Creemers
- Department of Orthopaedics, University Medical Center Utrecht, Room G05.228, P.O. Box 85500, 3508 GA, Utrecht, Netherlands
| | - Sibylle Grad
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
- ETH Zurich, Zurich, Switzerland
| | - Sonja Häckel
- Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland.
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22
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Briar KJ, Gregory DE. Combined flexion and compression negatively impact the mechanical integrity of the annulus fibrosus. Eur Spine J 2023; 32:831-838. [PMID: 36631712 DOI: 10.1007/s00586-022-07518-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 11/23/2022] [Accepted: 12/23/2022] [Indexed: 01/13/2023]
Abstract
PURPOSE To observe the effect of static flexion, in combination with compression, on the intralamellar and interlamellar matrix properties of the annulus fibrosus. METHODS C3/C4 cervical functional spinal units of porcine specimens were selected. Following preloading, all specimens were loaded under 1200 N axial compression in either a neutral or static end range flexion posture (15º) for 2 h. Following loading, six annulus samples were dissected from each disc: four single-layer and two multi-layer samples. The multi-layer samples underwent peel tests to quantify the mechanical properties of the interlamellar matrix while the single-layer samples underwent tensile tests to quantify the mechanical properties of the intralamellar matrix. Statistical comparisons between properties were performed to determine differences between postural condition, extraction location, and extraction depth. RESULTS Flexion elicited a decrease in lamellar adhesive strength (p = 0.045) and in single-layer failure strain (p = 0.03) when compared to a neutral posture. Flexion also had extraction depth-specific effects namely increased intralamellar matrix stiffness in the inner annulus when compared to neutral (p = 0019). Flexion also resulted in a significant decrease in toe region strain for the inner region of the annulus (p = 0.035). The inner region of the annulus was shown to have a significant increase in stress at 30% strain when compared to the outer region after flexion (p = 0.041). CONCLUSION The current findings suggest that the mechanical properties of the interlamellar and intralamellar matrices are sensitive to flexion, creating an environment that promotes an increased potential for damage to occur.
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Affiliation(s)
- K Josh Briar
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Diane E Gregory
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada. .,Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada.
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Zhu P, Kong F, Wu X, Dong Z, Du J, Mao Y, Zhou H, Liu Y, Mao H, Gu Y, Yang H, Geng D. A Minimally Invasive Annulus Fibrosus Needle Puncture Model of Intervertebral Disc Degeneration in Rats. World Neurosurg 2023; 169:e1-e8. [PMID: 36283650 DOI: 10.1016/j.wneu.2022.09.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 09/14/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND The needle puncture model in rats has been accepted as an ordinary model to induce intervertebral disc degeneration (IVDD). However, the model primarily penetrated the whole intervertebral disc, resulting in injury to the nucleus pulposus (NP) and annulus fibrosus (AF). The intention of this research was to explore a minimally invasive approach through needle puncture of the AF percutaneously in rats. METHODS Twenty SD rats underwent puncture at Co8/9 via a 20 G percutaneous needle. The needle was slowly advanced perpendicular to the tail skin to penetrate the whole AF without damaging the NP limited by a hand-made sheath. The X-rays and magnetic resonance imaging T2 relaxation was evaluated at 1, 2, and 3 weeks to assess the disc height index and signal changes. Histological and immunohistochemical staining of the IVD were obtained under a light microscope. RESULTS X-rays showed that the disc height had progressively narrowed to 49% of baseline 3 weeks after injury. magnetic resonance imaging evaluation demonstrated that the mean T2-weighted signal intensity at 3 weeks was 43% of that in the uninjured control group at the Co8/9 level. Histological staining demonstrated disorganized lamellae in the AF and decreased proteoglycan content and cellularity within the NP in the injured discs. CONCLUSIONS The present research demonstrates a reliable and convenient approach to induce an AF tear in rats through percutaneous needle puncture. This model reduces harm to the experimental animals significantly while imitating the progressive degeneration process. More importantly, the model confirmed that AF damage alone could lead to IVDD and provided a research method for AF degeneration in IVDD.
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Affiliation(s)
- Pengfei Zhu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Fanchen Kong
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiexing Wu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhongchen Dong
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiacheng Du
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yubo Mao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hong Zhou
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yijie Liu
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiqin Mao
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Ye Gu
- Department of Orthopaedics, Changshu Hospital Affiliated to Soochow University, First People's Hospital of Changshu City, Changshu, Jiangsu, China
| | - Huilin Yang
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China.
| | - Dechun Geng
- Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, China
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Sun H, Wang H, Zhang W, Mao H, Li B. Single-cell RNA sequencing reveals resident progenitor and vascularization-associated cell subpopulations in rat annulus fibrosus. J Orthop Translat 2022; 38:256-267. [PMID: 36568849 PMCID: PMC9758498 DOI: 10.1016/j.jot.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 12/14/2022] Open
Abstract
Background One of the main causes of low back pain is intervertebral disc degeneration (IDD). Annulus fibrosus (AF) is important for the integrity and functions of the intervertebral disc (IVD). However, the resident functional cell components such as progenitors and vascularization-associated cells in AF are yet to be fully identified. Purpose Identification of functional AF cell subpopulations including resident progenitors and vascularization-associated cells. Methods In this study, the single-cell RNA sequencing data of rat IVDs from a public database were analyzed using Seurat for cell clustering, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for functional analysis, StemID for stem cell identification, Monocle and RNA velocity for pseudotime differentiation trajectory validation, single-cell regulatory network inference and clustering (SCENIC) for gene regulatory network (GRN) analysis, and CellChat for cell-cell interaction analysis. Immunostaining on normal and degenerated rat IVDs, as well as human AF, was used for validations. Results From the data analysis, seven AF cell clusters were identified, including two newly discovered functional clusters, the Grem1 + subpopulation and the Lum + subpopulation. The Grem1 + subpopulation had progenitor characteristics, while the Lum + subpopulation was associated with vascularization during IDD. The GRN analysis showed that Sox9 and Id1 were among the key regulators in the Grem1 + subpopulation, and Nr2f2 and Creb5 could be responsible for the vascularization function in the Lum + subpopulation. Cell-cell interaction analysis revealed highly regulated cellular communications between these cells, and multiple signaling networks including PDGF and MIF signaling pathways were involved in the interactions. Conclusions Our results revealed two new functional AF cell subpopulations, with stemness and vascularization induction potential, respectively. The Translational potential of this article These findings complement our knowledge about IVDs, especially the AF, and in return provide potential cell source and regulation targets for IDD treatment and tissue repair. The existence of the cell subpopulations was also validated in human AF, which strengthen the clinical relevance of the findings.
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Affiliation(s)
- Heng Sun
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Huan Wang
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Weidong Zhang
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China
| | - Haijiao Mao
- The Affiliated Hospital of Medical School, Ningbo University, Ningbo, Zhejiang, China,Corresponding author.
| | - Bin Li
- Department of Orthopaedic Surgery, Orthopedic Institute, The First Affiliated Hospital, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, China,Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, China,Corresponding author. 178 Ganjiang Rd, Rm 201 Bldg 18, Soochow University (North Campus), Suzhou, Jiangsu, 215007, China.
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Saghari Fard MR, Krueger JP, Stich S, Berger P, Kühl AA, Sittinger M, Hartwig T, Endres M. A Biodegradable Polymeric Matrix for the Repair of Annulus Fibrosus Defects in Intervertebral Discs. Tissue Eng Regen Med 2022; 19:1311-20. [PMID: 35816226 DOI: 10.1007/s13770-022-00466-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Tissue defects in the annulus fibrosus (AF) due to intervertebral disc (IVD) degeneration or after nucleodiscectomy have little self-healing capacity. To prevent progressive degeneration of the IVD, the AF must be repaired. Biological closure has not yet been achieved and is a challenge for the research community. In this study, a scaffold made of absorbable poly (glycolic acid) (PGA) and hyaluronan (HA) that exhibit excellent biocompatibility and cell colonization properties was used to repair AF defects in an ovine model. METHODS A partial resection was performed in AF in L3/4 or L4/5 of 10 sheep and PGA-HA scaffolds were implanted on the defects (n = 5), while defects in the control group were left untreated (n = 5). Three months post-operation, the lumbar discs were sectioned and stained with hematoxylin and eosin and safranin-O/fast-green. Histological features including proteoglycan content, annular structure, cellular morphology, blood vessel ingrowth and tear/cleft formation were scored using a modified scoring scheme by 3 investigators and evaluated by a pathologist independently. RESULTS The treated AF exhibited significantly enhanced repair tissue structure with signs of proteoglycan formation compared to the untreated group. The median scores were 4.3 for the treated and 9.8 for the untreated group. Cystic degeneration, perivascular infiltration, inflammation and necrosis were only present in the untreated group. Blood vessel ingrowth and tear/cleft formation were increased, though not significant, in the untreated group while cell morphology was comparable in both groups. CONCLUSION PGA-HA scaffolds used for AF closure support repair tissue formation in an ovine lumbar disc defect model.
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Wade K, Berger-Roscher N, Saggese T, Rasche V, Wilke H. How annulus defects can act as initiation sites for herniation. Eur Spine J 2022; 31:1487-500. [PMID: 35174401 DOI: 10.1007/s00586-022-07132-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/13/2022] [Accepted: 01/25/2022] [Indexed: 10/19/2022]
Abstract
PURPOSE Both posture and loading rate are key factors in the herniation process and can determine the mechanism of disc failure. The aim of this study was to test the hypothesis that disruption visible with HR-MRI post-testing corresponds with microstructural features and further elucidate the mechanism by which this disruption weakens the disc. This will enable us to gain new insights into the herniation process. METHODS Thirty ovine lumbar spinal segments were subjected to combinations of four loading conditions (0-12° flexion, 0-9° lateral bending, 0-4° axial rotation, 0-1500 N axial compression) for 1000 loading cycles at 2 Hz in a dynamic disc loading simulator. The discs were scanned in an ultra-high field MRI (11.7 T) then examined using brightfield microscopy to examine their microstructure. RESULTS Four discs herniated and seven discs suffered nucleus displacement. These discs contained pre-existing defects in the central posterior annulus. Generally, following testing discs contained more posterior annulus disruption, Microstructural investigation revealed there was clear correspondence between HR-MRI and microstructural observations, and that the mid-outer annular-endplate junction had failed in all discs examined in this study. CONCLUSIONS While all discs suffered outer annulus damage, only the discs containing pre-existing defects herniated. These pre-existing defects weakened the inner and mid annulus, allowing herniation to occur once the mid and outer annular wall was compromised. We propose this can occur during the degenerative cascade.
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Werbner B, Lee M, Lee A, Yang L, Habib M, Fields AJ, O'Connell GD. Non-enzymatic glycation of annulus fibrosus alters tissue-level failure mechanics in tension. J Mech Behav Biomed Mater 2022; 126:104992. [PMID: 34864399 DOI: 10.1016/j.jmbbm.2021.104992] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 11/18/2021] [Accepted: 11/18/2021] [Indexed: 10/19/2022]
Abstract
Advanced-glycation end products (AGEs) are known to accumulate in biological tissues with age and at an accelerated rate in patients with diabetes and chronic kidney disease. Clinically, diabetes has been linked to increased frequency and severity of back pain, accelerated disc degeneration, and an increased risk of disc herniation. Despite significant clinical evidence suggesting that diabetes-induced AGEs may play a role in intervertebral disc failure and substantial previous work investigating the effects of AGEs on bone, cartilage, and tendon mechanics, the effects of AGEs on annulus fibrosus (AF) failure mechanics have not yet been reported. Thus, the aim of this study was to determine the relationship between physiological levels of AGEs and AF tensile mechanics at two distinct loading rates. In vitro glycation treatments with methylglyoxal were applied to minimize changes in tissue hydration and induce two distinct levels of AGEs based on values measured from human AF tissues. In vitro glycation increased modulus by 48-99% and failure stress by 45-104% versus control and decreased post-failure energy absorption capacity by 15-32% versus control (ANOVA p < 0.0001 on means; range given across two loading rates and glycation levels). AGE content correlated strongly with modulus (R = 0.74, p < 0.0001) and failure stress (R = 0.70, p < 0.0001) and moderately with post-failure energy absorption capacity (R = 0.62, p < 0.0001). Failure strain was reduced by 10-17% at the high-glycation level (ANOVA p = 0.01). Tissue water content remained near or just above fresh-tissue levels for all groups. The alterations in mechanics with glycation reported here are consistent with trends from other connective tissues but do not fully explain the clinical predisposition of diabetics to disc herniation. The results from this study may be used in the development of advanced computational models that aim to study disc disease progression and to provide a deeper understanding of altered structure-function relationships that may lead to tissue dysfunction and failure with aging and disease.
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Affiliation(s)
- Benjamin Werbner
- Department of Mechanical Engineering University of California, Berkeley, USA
| | - Matthew Lee
- Department of Mechanical Engineering University of California, Berkeley, USA
| | - Allan Lee
- Department of Bioengineering University of California, Berkeley, USA
| | - Linda Yang
- Department of Bioengineering University of California, Berkeley, USA
| | - Mohamed Habib
- Department of Orthopaedic Surgery University of California, San Francisco, USA; Mechanical Engineering Department Al Azhar University, Cairo, Egypt
| | - Aaron J Fields
- Department of Orthopaedic Surgery University of California, San Francisco, USA
| | - Grace D O'Connell
- Department of Mechanical Engineering University of California, Berkeley, USA; Department of Orthopaedic Surgery University of California, San Francisco, USA.
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Castro AL, Ribeiro-Machado C, Oliveira CM, Teixeira GQ, Neidlinger-Wilke C, Pereira P, Vaz R, Barbosa MA, Gonçalves RM. Fibrotic alterations in human annulus fibrosus correlate with progression of intervertebral disc herniation. Arthritis Res Ther 2022; 24:25. [PMID: 35039075 DOI: 10.1186/s13075-021-02690-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Intervertebral disc (IVD) herniation is characterized by annulus fibrosus failure (AF) in containing the nucleus pulposus (NP). IVD herniation involves cellular and extracellular matrix (ECM) alterations that have been associated with tissue fibrosis, although still poorly investigated. METHODS Here, fibrotic alterations in human AF were evaluated, by characterizing the herniated ECM. Human AF samples (herniated lumbar IVD (n = 39, age 24-83) and scoliosis controls (n = 6, age 15-21)) were processed for transmission electron microscopy and histological/immunohistochemical analysis of fibrotic markers. Correlations between the fibrotic markers in AF ECM and the degree of NP containment (protused, contained and uncontained) and patients' age were conducted. RESULTS Our results demonstrate that with herniation progression, i.e. loss of NP containment, human AF presents less stained area of sulphated glycosaminoglycans and collagen I, being collagen I fibres thinner and disorganized. On the other hand, fibronectin stained area and percentage of α-smooth muscle actin+ cells increase in human AF, while matrix metalloproteinase-12 (MMP12) production and percentage of macrophages (CD68+ cells) remain constant. These structural and biochemical fibrotic alterations observed in human AF with herniation progression occur independently of the age. CONCLUSIONS The characterization of human AF here conducted evidence the presence of fibrosis in degenerated IVD, while highlighting the importance of considering the herniation progression stage, despite the patients' age, for a better understanding of the mechanisms behind AF failure and IVD herniation.
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Kirnaz S, Singh S, Capadona C, Lintz M, Goldberg JL, McGrath LB, Medary B, Sommer F, Bonassar LJ, Härtl R. Innovative Biological Treatment Methods for Degenerative Disc Disease. World Neurosurg 2021; 157:282-299. [PMID: 34929786 DOI: 10.1016/j.wneu.2021.09.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 10/19/2022]
Abstract
Low back pain is the leading cause of work absences and years lived with disability, and it is often associated with degenerative disc disease. In recent years, biological treatment approaches such as the use of growth factors, cell injections, annulus fibrosus (AF) repair, nucleus pulposus replacement, and tissue-engineered discs have been explored as means for preventing or reversing degenerative disc disease. Both animal and clinical studies have shown promising results for cell-based therapy on the grounds of its regenerative potential. Clinical data also indicate that stem cell injection is safe when appropriately performed, albeit its long-term safety and efficacy are yet to be explored. Numerous challenges also remain to be overcome, such as isolating, differentiating, and preconditioning the disc cells, as well as managing the nutrient-deficient and oxygen-deficient micromilieu of the intervertebral disc (IVD). AF repair methods including devices used in clinical trials have shown success in decreasing reherniation rates and improving overall clinical outcomes. In addition, recent studies that combined AF repair and nucleus pulposus replacement have shown improved biomechanical stability in IVDs after the combined treatment. Tissue-engineered IVDs for total disc replacement are still being developed, and future studies are necessary to overcome the challenges in their delivery, efficacy, and safety.
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Affiliation(s)
- Sertac Kirnaz
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Sunidhi Singh
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Charisse Capadona
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Marianne Lintz
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Jacob L Goldberg
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Lynn B McGrath
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Branden Medary
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Fabian Sommer
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA
| | - Lawrence J Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
| | - Roger Härtl
- Department of Neurological Surgery, Weill Cornell Medicine Brain and Spine Center, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, USA.
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Tamoud A, Zaïri F, Mesbah A, Zaïri F. Modeling multiaxial damage regional variation in human annulus fibrosus. Acta Biomater 2021; 136:375-88. [PMID: 34547514 DOI: 10.1016/j.actbio.2021.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/08/2021] [Accepted: 09/13/2021] [Indexed: 01/03/2023]
Abstract
In the present article, a fully three-dimensional human annulus fibrosus model is developed by considering the regional variation of the complex structural organization of collagen network at different scales to predict the regional anisotropic multiaxial damage of the intervertebral disc. The model parameters are identified using experimental data considering as elementary structural unit, the single annulus lamellae stretched till failure along the micro-sized collagen fibers. The multi-layered lamellar/inter-lamellar annulus model is constructed by considering the effective interactions between adjacent layers and the chemical-induced volumetric strain. The regional dependent model predictions are analyzed under various loading modes and compared to experimental data when available. The stretching along the circumferential and radial directions till failure serves to check the predictive capacities of the annulus model. Model results under simple shear, biaxial stretching and plane-strain compression are further presented and discussed. Finally, a full disc model is constructed using the regional annulus model and simulations are presented to assess the most likely failed areas under disc axial compression. STATEMENT OF SIGNIFICANCE: The damage in annulus soft tissues is a complex multiscale phenomenon due to a complex structural arrangement of collagen network at different scales of hierarchical organization. A fully three-dimensional constitutive representation that considers the regional variation of the structural complexity to estimate annulus multiaxial mechanics till failure has not yet been developed. Here, a model is developed to predict deformation-induced damage and failure of annulus under multiaxial loading histories considering as time-dependent physical process both chemical-induced volumetric effects and damage accumulation. After model identification using single lamellae extracted from different disc regions, the model predictability is verified for various multiaxial elementary loading modes representative of the spine movement. The heterogeneous mechanics of a full human disc model is finally presented.
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Werbner B, Zhou M, McMindes N, Lee A, Lee M, O'Connell GD. Saline-polyethylene glycol blends preserve in vitro annulus fibrosus hydration and mechanics: An experimental and finite-element analysis. J Mech Behav Biomed Mater 2021; 125:104951. [PMID: 34749204 DOI: 10.1016/j.jmbbm.2021.104951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 10/23/2021] [Accepted: 10/27/2021] [Indexed: 01/01/2023]
Abstract
Precise control of tissue water content is essential for ensuring accurate, repeatable, and physiologically relevant measurements of tissue mechanics and biochemical composition. While previous studies have found that saline and polyethylene glycol (PEG) blends were effective at controlling tendon and ligament hydration levels, this work has yet to be extended to the annulus fibrosus (AF). Thus, the first objective of this study was to determine and validate an optimal buffer solution for targeting and maintaining hydration levels of tissue-level AF specimens in vitro. This was accomplished by measuring the transient swelling behavior of bovine AF specimens in phosphate-buffered saline (PBS) and PEG buffers across a wide range of concentrations. Sub-failure, failure, and post-failure mechanics were measured to determine the relationship between changes in tissue hydration and tensile mechanical response. The effect of each buffer solution on tissue composition was also assessed. The second objective of this study was to assess the feasibility and effectiveness of using multi-phasic finite element models to investigate tissue swelling and mechanical responses in different external buffer solutions. A solution containing 6.25%w/v PBS and 6.25%w/v PEG effectively maintained tissue-level AF specimen hydration at fresh-frozen levels after 18 h in solution. Modulus, failure stress, failure strain, and post-failure toughness of specimens soaked in this solution for 18 h closely matched those of fresh-frozen specimens. In contrast, specimens soaked in 0.9%w/v PBS swelled over 100% after 18 h and exhibited significantly diminished sub-failure and failure properties compared to fresh-frozen controls. The increased cross-sectional area with swelling contributed to but was not sufficient to explain the diminished mechanics of PBS-soaked specimens, suggesting additional sub-tissue scale mechanisms. Computational simulations of these specimens generally agreed with experimental results, highlighting the feasibility and importance of including a fluid-phase description when models aim to provide accurate predictions of biological tissue responses. As numerous previous studies suggest that tissue hydration plays a central role in maintaining proper mechanical and biological function, robust methods for controlling hydration levels are essential as the field advances in probing the relationship between tissue hydration, aging, injury, and disease.
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Affiliation(s)
- Benjamin Werbner
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Minhao Zhou
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Nicole McMindes
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Allan Lee
- Department of Bioengineering, University of California, Berkeley, USA
| | - Matthew Lee
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, USA; Department of Orthopaedic Surgery, University of California, San Francisco, USA.
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Rasoulian A, Vakili-Tahami F, Smit TH. Linear and Nonlinear Biphasic Mechanical Properties of Goat IVDs Under Different Swelling Conditions in Confined Compression. Ann Biomed Eng 2021; 49:3296-3309. [PMID: 34480262 DOI: 10.1007/s10439-021-02856-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/18/2021] [Indexed: 11/25/2022]
Abstract
To define technical specifications for artificial substitutes, it is necessary to model their mechanical behaviour. Here we studied the linear and nonlinear biphasic models for Nucleus Pulposus (NP) and Annulus Fibrosus (AF). The associated material parameters were obtained using confined compression stress relaxation tests on goat intervertebral disc (IVD) samples. The first parameter, aggregate modulus HA0, which essentially describes load-bearing capacity of the solid phase, was larger for AF (HA0 = 0.53 ± 0.06 MPa) than for NP (HA0 = 0.26 ± 0.04 MPa). For hydraulic permeability, which quantifies the ability to transmit interstitial fluid, it was the opposite (k0 = (0.20 ± 0.07) × 10-15 m4/Ns for AF and k0 = (0.67 ± 0.08)×10-15 m4/Ns for NP). The values of nonlinearity coefficients, nonlinear stiffening coefficient β and non-dimensional nonlinear permeability coefficient M, reflected that these tissues had nonlinear elastic behaviour and permeability. Also, investigating the effect of swelling conditions in sample preparation showed that for both AF and NP, confined-swollen samples had higher aggregate modulus and lower permeability values compared to the free-swollen ones. The quantitative description of the nonlinear properties of AF and NP provided a better understanding of IVD behaviour as well as technical specifications for their artificial substitutes.
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Affiliation(s)
- Akbar Rasoulian
- Department of Mechanical Engineering, University of Tabriz, 29 Bahman Blvd., 5166616471, Tabriz, Iran.,Department of Orthopedic Surgery, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, De Boelelaan 1117, Amsterdam, 1081 HV, The Netherlands
| | - Farid Vakili-Tahami
- Department of Mechanical Engineering, University of Tabriz, 29 Bahman Blvd., 5166616471, Tabriz, Iran.
| | - Theodoor H Smit
- Department of Orthopedic Surgery, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, De Boelelaan 1117, Amsterdam, 1081 HV, The Netherlands.,Department of Medical Biology, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, 1085 AZ, The Netherlands
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Żak M, Pezowicz C. Effect of overload on changes in mechanical and structural properties of the annulus fibrosus of the intervertebral disc. Biomech Model Mechanobiol 2021; 20:2259-2267. [PMID: 34431033 PMCID: PMC8595169 DOI: 10.1007/s10237-021-01505-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 08/12/2021] [Indexed: 11/02/2022]
Abstract
The research focussed on analysing structural and mechanical properties in the intervertebral disc (IVD), caused by long-term cyclic loading. Spinal motion segments were divided into two groups: the control (C), and the group in which it was analysed the impact of posterior column in the load-bearing system of the spine-specimens with intact posterior column (IPC) and without posterior column (WPC). To evaluate the structural and mechanical changes, the specimens were tested with simulation of 100,000 compression-flexion load cycles after which it was performed macroscopic analysis. Mechanical properties of the annulus fibrosis (AF) from the anterior and posterior regions of the IVD were tested at the uniaxial tension test. The stiffness coefficient values were statistically 32% higher in the WPC group (110 N/mm) than in the IPC (79 N/mm). The dynamics of increase in this parameter does not correspond with the course of decrease in height loss. WPC segments revealed clear structural changes that mainly involve the posterior regions of the IVD (bulging and delamination with the effect of separation of collagen fibre bundles). Pathological changes also caused decreases in the value of stress in the AF. The greatest changes in the stress value about group C (7.43 ± 4.49 MPa) were observed in the front part of the fibrous ring, where this value was for IPC 4.49 ± 4.78 MPa and WPC 2.56 ± 1.01 MPa. The research indicates that the applied load model allows simulating damage that occurs in pathological IVD. And the posterior column's presence affects this change's dynamics, structural and mechanical properties of AF.
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Affiliation(s)
- Małgorzata Żak
- Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Łukasiewicza 7/9, 50-371, Wrocław, Poland.
| | - Celina Pezowicz
- Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Łukasiewicza 7/9, 50-371, Wrocław, Poland
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Kudelko M, Chen P, Tam V, Zhang Y, Kong OY, Sharma R, Au TY, To MKT, Cheah KS, Chan WC, Chan D. PRIMUS: Comprehensive proteomics of mouse intervertebral discs that inform novel biology and relevance to human disease modelling. Matrix Biol Plus 2021; 12:100082. [PMID: 34409283 PMCID: PMC8361275 DOI: 10.1016/j.mbplus.2021.100082] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/08/2021] [Accepted: 07/15/2021] [Indexed: 12/21/2022] Open
Abstract
Proteomics of healthy mouse IVDs differentiating compartments and spine levels. NP cells feature vacuoles with lysosomal, transport and cell–cell communication functions. Collagen XII, decorin and other ECM proteins contribute to function of the AF. Distinct proteomics between lumbar and tail discs. Mouse is a relevant model for human disc biology but care is needed in its use.
Mice are commonly used to study intervertebral disc (IVD) biology and related diseases such as IVD degeneration. Discs from both the lumbar and tail regions are used. However, little is known about compartmental characteristics in the different regions, nor their relevance to the human setting, where a functional IVD unit depends on a homeostatic proteome. Here, we address these major gaps through comprehensive proteomic profiling and in-depth analyses of 8-week-old healthy murine discs, followed by comparisons with human. Leveraging on a dataset of over 2,700 proteins from 31 proteomic profiles, we identified key molecular and cellular differences between disc compartments and spine levels, but not gender. The nucleus pulposus (NP) and annulus fibrosus (AF) compartments differ the most, both in matrisome and cellularity contents. Differences in the matrisome are consistent with the fibrous nature required for tensile strength in the AF and hydration property in the NP. Novel findings for the NP cells included an enrichment in cell junction proteins for cell–cell communication (Cdh2, Dsp and Gja1) and osmoregulation (Slc12a2 and Wnk1). In NP cells, we detected heterogeneity of vacuolar organelles; where about half have potential lysosomal function (Vamp3, Copb2, Lamp1/2, Lamtor1), some contain lipid droplets and others with undefined contents. The AF is enriched in proteins for the oxidative stress responses (Sod3 and Clu). Interestingly, mitochondrial proteins are elevated in the lumbar than tail IVDs that may reflect differences in metabolic requirement. Relative to the human, cellular and structural information are conserved for the AF. Even though the NP is more divergent between mouse and human, there are similarities at the level of cell biology. Further, common cross-species markers were identified for both NP (KRT8/19, CD109) and AF (COL12A1). Overall, mouse is a relevant model to study IVD biology, and an understanding of the limitation will facilitate research planning and data interpretation, maximizing the translation of research findings to human IVDs.
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Affiliation(s)
- Mateusz Kudelko
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Peikai Chen
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- Department of Orthopaedics Surgery and Traumatology, The University of Hong Kong -Shenzhen Hospital (HKU-SZH), Shenzhen, China
| | - Vivian Tam
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Ying Zhang
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Oi-Yin Kong
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Rakesh Sharma
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- Proteomics and Metabolomics Core Facility, The University of Hong Kong, Pokfulam, Hong Kong
| | - Tiffany Y.K. Au
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Michael Kai-Tsun To
- Department of Orthopaedics Surgery and Traumatology, The University of Hong Kong -Shenzhen Hospital (HKU-SZH), Shenzhen, China
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong
| | - Kathryn S.E. Cheah
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Wilson C.W. Chan
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- Department of Orthopaedics Surgery and Traumatology, The University of Hong Kong -Shenzhen Hospital (HKU-SZH), Shenzhen, China
| | - Danny Chan
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong
- Department of Orthopaedics Surgery and Traumatology, The University of Hong Kong -Shenzhen Hospital (HKU-SZH), Shenzhen, China
- Corresponding author at: School of Biomedical Sciences, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong.
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McAlinden A, Hudson DM, Fernandes AA, Ravindran S, Fernandes RJ. Biochemical and immuno-histochemical localization of type IIA procollagen in annulus fibrosus of mature bovine intervertebral disc. Matrix Biol Plus 2021; 12:100077. [PMID: 34337380 PMCID: PMC8313739 DOI: 10.1016/j.mbplus.2021.100077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/08/2021] [Accepted: 06/24/2021] [Indexed: 11/05/2022] Open
Abstract
For next generation tissue-engineered constructs and regenerative medicine to succeed clinically, the basic biology and extracellular matrix composition of tissues that these repair techniques seek to restore have to be fully determined. Using the latest reagents coupled with tried and tested methodologies, we continue to uncover previously undetected structural proteins in mature intervertebral disc. In this study we show that the “embryonic” type IIA procollagen isoform (containing a cysteine-rich amino propeptide) was biochemically detectable in the annulus fibrosus of both calf and mature steer caudal intervertebral discs, but not in the nucleus pulposus where the type IIB isoform was predominantly localized. Specifically, the triple-helical type IIA procollagen isoform immunolocalized in the outer margins of the inner annulus fibrosus. Triple helical processed type II collagen exclusively localized within the inter-lamellae regions and with type IIA procollagen in the intra-lamellae regions. Mass spectrometry of the α1(II) collagen chains from the region where type IIA procollagen localized showed high 3-hydroxylation of Proline-944, a post-translational modification that is correlated with thin collagen fibrils as in the nucleus pulposus. The findings implicate small diameter fibrils of type IIA procollagen in select regions of the annulus fibrosus where it likely contributes to the organization of collagen bundles and structural properties within the type I-type II collagen transition zone.
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Affiliation(s)
- Audrey McAlinden
- Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO, USA.,Department of Cell Biology & Physiology, Washington University School of Medicine, St Louis, MO, USA.,Shriners Hospitals for Children- St Louis, MO, USA
| | - David M Hudson
- Department of Orthopaedic & Sports Medicine, University of Washington, Seattle, WA, USA
| | - Aysel A Fernandes
- Department of Orthopaedic & Sports Medicine, University of Washington, Seattle, WA, USA
| | - Soumya Ravindran
- Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO, USA
| | - Russell J Fernandes
- Department of Orthopaedic & Sports Medicine, University of Washington, Seattle, WA, USA
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36
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McMorran JG, Gregory DE. The effect of compressive loading rate on annulus fibrosus strength following endplate fracture. Med Eng Phys 2021; 93:17-26. [PMID: 34154771 DOI: 10.1016/j.medengphy.2021.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 04/14/2021] [Accepted: 05/18/2021] [Indexed: 02/07/2023]
Abstract
Intervertebral disc degeneration poses a considerable healthcare challenge, although the process is not well understood. Endplate fracture marks severe biomechanical compromise in a segment and may be correlated with degeneration of the disc. The purpose of this experiment was to investigate the relationship between endplate fracture velocity and damage to the annulus fibrosus. Following overnight-thawing, 27 frozen porcine cervical spines were dissected into motion segments (vertebra-disc-vertebra) and compressed until fracture at one of three loading rates (fast=15 mm/s, medium=1.5 mm/s, and slow=0.15 mm/s), or remained unfractured (control). Two annular samples were extracted and mechanically tested from each segment: 1) Bilayer samples underwent uniaxial tension to a stretch-ratio of 1.5; 2) Multilayer samples were delaminated with a 180° peel test configuration. All three rates of compression resulted in specimen fracture observed in the endplate and/or vertebra with varying degree of severity. Significant differences were detected in compressive strength and stiffness of motion segments when loaded at different rates of compression; interestingly these differences were not observed in the mechanical properties of the annulus fibrosus suggesting that at slow rates of loading, fracture of the endplate precedes destruction of the annulus fibrosus. In corroboration of these findings, gross and histological analysis reported no signs of annular disruption, strengthening assertions that annular damage did not occur.
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Affiliation(s)
- John G McMorran
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave West, Waterloo N2L3C5, ON Canada
| | - Diane E Gregory
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave West, Waterloo N2L3C5, ON Canada; Department of Health Sciences, Wilfrid Laurier University, 75 University Ave West, Waterloo N2L3C5, Ontario, Canada.
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37
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Wang D, Hartman R, Han C, Zhou CM, Couch B, Malkamaki M, Roginskaya V, Van Houten B, Mullett SJ, Wendell SG, Jurczak MJ, Kang J, Lee J, Sowa G, Vo N. Lactate oxidative phosphorylation by annulus fibrosus cells: evidence for lactate-dependent metabolic symbiosis in intervertebral discs. Arthritis Res Ther 2021; 23:145. [PMID: 34020698 PMCID: PMC8139157 DOI: 10.1186/s13075-021-02501-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 04/03/2021] [Indexed: 01/03/2023] Open
Abstract
Background Intervertebral disc degeneration contributes to low back pain. The avascular intervertebral disc consists of a central hypoxic nucleus pulpous (NP) surrounded by the more oxygenated annulus fibrosus (AF). Lactic acid, an abundant end-product of NP glycolysis, has long been viewed as a harmful waste that acidifies disc tissue and decreases cell viability and function. As lactic acid is readily converted into lactate in disc tissue, the objective of this study was to determine whether lactate could be used by AF cells as a carbon source rather than being removed from disc tissue as a waste byproduct. Methods Import and conversion of lactate to tricarboxylic acid (TCA) cycle intermediates and amino acids in rabbit AF cells were measured by heavy-isotope (13C-lactate) tracing experiments using mass spectrometry. Levels of protein expression of lactate converting enzymes, lactate importer and exporter in NP and AF tissues were quantified by Western blots. Effects of lactate on proteoglycan (35S-sulfate) and collagen (3H-proline) matrix protein synthesis and oxidative phosphorylation (Seahorse XFe96 Extracellular Flux Analyzer) in AF cells were assessed. Results Heavy-isotope tracing experiments revealed that AF cells imported and converted lactate into TCA cycle intermediates and amino acids using in vitro cell culture and in vivo models. Addition of exogenous lactate (4mM) in culture media induced expression of the lactate importer MCT1 and increased oxygen consumption rate by 50%, mitochondrial ATP-linked respiration by 30%, and collagen synthesis by 50% in AF cell cultures grown under physiologic oxygen (2-5% O2) and glucose concentration (1-5mM). AF tissue highly expresses MCT1, LDH-H, an enzyme that preferentially converts lactate to pyruvate, and PDH, an enzyme that converts pyruvate to acetyl-coA. In contrast, NP tissue highly expresses MCT4, a lactate exporter, and LDH-M, an enzyme that preferentially converts pyruvate to lactate. Conclusions These findings support disc lactate-dependent metabolic symbiosis in which lactate produced by the hypoxic, glycolytic NP cells is utilized by the more oxygenated AF cells via oxidative phosphorylation for energy and matrix production, thus shifting the current research paradigm of viewing disc lactate as a waste product to considering it as an important biofuel. These scientifically impactful results suggest novel therapeutic targets in disc metabolism and degeneration. Supplementary Information The online version contains supplementary material available at 10.1186/s13075-021-02501-2.
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Affiliation(s)
- Dong Wang
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA
| | - Robert Hartman
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA.,University of Pittsburgh Medical Center Enterprises, Pittsburgh, PA, 15213, USA
| | - Chao Han
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA.,Tianjin Hospital, 406 Jiefang South Road Hexi District, Tianjin, PR China
| | - Chao-Ming Zhou
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA
| | - Brandon Couch
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA
| | - Matias Malkamaki
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA
| | - Vera Roginskaya
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA
| | - Bennett Van Houten
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA
| | - Steven J Mullett
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.,Health Sciences Metabolomics and Lipidomics Core, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stacy G Wendell
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.,Health Sciences Metabolomics and Lipidomics Core, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael J Jurczak
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, PA, USA.,Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - James Kang
- Department of Orthopedics, Brigham and Women's Hospital, School of Medicine, Harvard University, 75 Francis Street, Boston, MA, 02115, USA
| | - Joon Lee
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA
| | - Gwendolyn Sowa
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA. .,Department of Physical Medicine and Rehabilitation, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - Nam Vo
- Department of Orthopaedic Surgery, Ferguson Laboratory for Orthopedic and Spine Research, University of Pittsburgh, 200 Lothrop Street, E1644 Biomedical Science Tower, Pittsburgh, PA, 15261, USA.
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Ghezelbash F, Eskandari AH, Shirazi-Adl A, Kazempour M, Tavakoli J, Baghani M, Costi JJ. Modeling of human intervertebral disc annulus fibrosus with complex multi-fiber networks. Acta Biomater 2021; 123:208-221. [PMID: 33453409 DOI: 10.1016/j.actbio.2020.12.062] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/07/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022]
Abstract
Collagen fibers within the annulus fibrosus (AF) lamellae are unidirectionally aligned with alternating orientations between adjacent layers. AF constitutive models often combine two adjacent lamellae into a single equivalent layer containing two fiber networks with a crisscross pattern. Additionally, AF models overlook the inter-lamellar matrix (ILM) as well as elastic fiber networks in between lamellae. We developed a nonhomogenous micromechanical model as well as two coarser homogenous hyperelastic and microplane models of the human AF, and compared their performances against measurements (tissue level uniaxial and biaxial tests as well as whole disc experiments) and seven published hyperelastic models. The micromechanical model had a realistic non-homogenous distribution of collagen fiber networks within each lamella and elastic fiber network in the ILM. For small matrix linear moduli (<0.2 MPa), the ILM showed substantial anisotropy (>10%) due to the elastic fiber network. However, at moduli >0.2 MPa, the effects of the elastic fiber network on differences in stress-strain responses at different directions disappeared (<10%). Variations in sample geometry and boundary conditions (due to uncertainty) markedly affected stress-strain responses of the tissue in uniaxial and biaxial tests (up to 16 times). In tissue level tests, therefore, simulations should represent testing conditions (e.g., boundary conditions, specimen geometry, preloads) as closely as possible. Stress/strain fields estimated from the single equivalent layer approach (conventional method) yielded different results from those predicted by the anatomically more accurate apparoach (i.e., layerwise). In addition, in a disc under a compressive force (symmetric loading), asymmetric stress-strain distributions were computed when using a layerwise simulation. Although all developed and selected published AF models predicted gross compression-displacement responses of the whole disc within the range of measured data, some showed excessively stiff or compliant responses under tissue-level uniaxial/biaxial tests. This study emphasizes, when constructing and validating constitutive models of AF, the importance of the proper simulation of individual lamellae as distinct layers, and testing parameters (sample geometric dimensions/loading/boundary conditions).
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Affiliation(s)
- Farshid Ghezelbash
- Department of Mechanical Engineering, Polytechnique Montreal, Quebec, Canada.
| | - Amir Hossein Eskandari
- Institut de recherche Robert Sauvé en santé et en sécurité du travail, Montréal, Québec, Canada
| | | | - Morteza Kazempour
- Mechanical Engineering Department, University of Tehran, Tehran, Iran
| | - Javad Tavakoli
- Centre for Health Technologies, School of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW, Australia; SpineLabs, St George & Sutherland Clinical School, The University of New South Wales, NSW, Australia
| | - Mostafa Baghani
- Mechanical Engineering Department, University of Tehran, Tehran, Iran
| | - John J Costi
- Biomechanics and Implants Research Group, Medical Device Research Institute, College of Science and Engineering, Flinders University, Adelaide, Australia
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Page MI, Linde PE, Puttlitz CM. Computational modeling to predict the micromechanical environment in tissue engineering scaffolds. J Biomech 2021; 120:110355. [PMID: 33711600 DOI: 10.1016/j.jbiomech.2021.110355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/25/2021] [Accepted: 02/22/2021] [Indexed: 11/26/2022]
Abstract
Cell fate in tissue engineering (TE) strategies is paramount to regenerate healthy, functional organs. The mechanical loads experienced by cells play an important role in cell fate. However, in TE scaffolds with a cell-laden hydrogel matrix, it is prohibitively complex to prescribe and measure this cellular micromechanical environment (CME). Accordingly, this study aimed to develop a finite element (FE) model of a TE scaffold unit cell that can be subsequently implemented to predict the CME and cell fates under prescribed loading. The compressible hyperelastic mechanics of a fibrin hydrogel were characterized by fitting unconfined compression and confined compression experimental data. This material model was implemented in a unit cell FE model of a TE scaffold. The FE mesh and boundary conditions were evaluated with respect to the mechanical response of a region of interest (ROI). A compressible second-order reduced polynomial hyperelastic model gave the best fit to the experimental data (C10 = 1.72 × 10-4, C20 = 3.83 × 10-4, D1 = 3.41, D2 = 8.06 × 10-2). A mesh with seed sizes of 40 µm and 60 µm in the ROI and non-ROI regions, respectively, yielded a converged model in 54 min. The in-plane boundary conditions demonstrated minimal influence on ROI mechanics for a 2-by-2 unit cell. However, the out-of-plane boundary conditions did exhibit an appreciable influence on ROI mechanics for a two bilayer unit cell. Overall, the developed unit cell model facilitates the modeling of the mechanical state of a cell-laden hydrogel within a TE scaffold under prescribed loading. This model will be utilized to characterize the CME in future studies, and 3D micromechanical criteria may be applied to predict cell fate in these scaffolds.
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Affiliation(s)
- Mitchell I Page
- Department of Mechanical Engineering, Colorado State University, Ft Collins, CO, USA
| | - Peter E Linde
- School of Biomedical Engineering, Colorado State University, Ft Collins, CO, USA
| | - Christian M Puttlitz
- Department of Mechanical Engineering, Colorado State University, Ft Collins, CO, USA; School of Biomedical Engineering, Colorado State University, Ft Collins, CO, USA; Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA.
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40
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Sabouri P, Hashemi A. Influence of crack length and anatomical location on the fracture toughness of annulus fibrosus. Med Eng Phys 2021; 88:1-8. [PMID: 33485508 DOI: 10.1016/j.medengphy.2020.11.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 10/16/2020] [Accepted: 11/21/2020] [Indexed: 01/07/2023]
Abstract
Fracture toughness (Jc) of a soft biological tissue is an important mechanical property that characterizes its resistance to crack or tear extension. To date, no information is available on fracture toughness of annulus fibrosus (AF); therefore, its defect tolerance is not known. The present study modified a previously introduced method to determine Jc of ovine AF. Then, the effect of the notch length on the failure pattern and Jc was investigated. Also, the test samples of anterior and lateral regions were collected to determine the effect of the location on Jc. Results showed that for a notch length of less than 45% of total width, no crack extension occurred, but for a notch length above 45% of the width, crack propagation and ultimately the failure of the AF were observed. However, statistical analysis indicated no significant difference on Jc (p = 0.5) for the initial notch length of 50% and 70% of total width. The fracture toughness was significantly higher for the samples extracted from the lateral site than those from the anterior site (p < 0.05). Dissimilar failure patterns were observed for different initial notch lengths. Among the parameters studied, the defect tolerance of AF was dependent on the initial tear size.
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Affiliation(s)
- Pouya Sabouri
- Biomechanical Engineering Group, Biomedical Engineering Department, Amirkabir University of Technology (Tehran Polytechnic), Tehran 15875-4413, Iran
| | - Ata Hashemi
- Biomechanical Engineering Group, Biomedical Engineering Department, Amirkabir University of Technology (Tehran Polytechnic), Tehran 15875-4413, Iran.
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41
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Kienzler JC, Fandino J, Van de Kelft E, Eustacchio S, Bouma GJ; Barricaid® Annular Closure RCT Study Group. Risk factors for early reherniation after lumbar discectomy with or without annular closure: results of a multicenter randomized controlled study. Acta Neurochir (Wien) 2021; 163:259-68. [PMID: 33085021 DOI: 10.1007/s00701-020-04505-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/17/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Reherniation after lumbar discectomy is classified as a failure and occurs in 3 to 18% of cases. Various risk factors for reherniation such as age, sex, body mass index, smoking, and size of annular defect have been reported. The aim of this study was to identify risk factors for early reherniation after one-level lumbar discectomy with or without annular closure within 3 months after surgery. METHODS This study is based on data analysis of a prospective, multicenter randomized controlled trial in Europe. Patients included underwent standard lumbar discectomy-with or without implantation of an annular closure device (ACD). Enrollment of 554 patients in 21 centers in Europe (Germany, Switzerland, Austria, Belgium, The Netherlands, and France) started in 2010 and was completed in October 2014. A total of 276 patients were randomized to the ACD group (ACG) and 278 patients to the control group (CG). RESULTS Four (1.5%) symptomatic reherniations occurred in the ACG and 18 (6.5%) in the CG. In the overall population, a significant correlation was found with recurrent herniation for disc degeneration (Pfirrmann p = 0.009) and a trend for current smoker status (p = 0.07). In CG, age ≥ 50 years (p = 0.05) and disc degeneration (Pfirrmann p = 0.026, Kellgren and Lawrence p = 0.013) were predictive factors for reherniation. CONCLUSION In the current study, risk factors for early recurrent disc herniation after lumbar discectomy were age ≥ 50 years and moderate disc degeneration. The annular closure device reduced the risk of early reherniation. TRIAL REGISTRATION Clinicaltrials.gov NCT01283438.
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42
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van den Akker GGH, Cremers A, Surtel DAM, Voncken W, Welting TJM. Isolation of Nucleus Pulposus and Annulus Fibrosus Cells from the Intervertebral Disc. Methods Mol Biol 2021; 2221:41-52. [PMID: 32979197 DOI: 10.1007/978-1-0716-0989-7_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells isolated from the intervertebral disc are often used for in vitro experimentation. Correctly separating the intervertebral disc tissue in annulus fibrosus and nucleus pulposus is particularly challenging when working with surplus material from surgery or specimens from donors with an advanced age. Moreover, lineage controls are only sparsely reported to verify tissue of origin. Here we describe an approach to intervertebral disc cell isolation from human and bovine origin.
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Affiliation(s)
- Guus G H van den Akker
- Laboratory for Experimental Orthopedics, Department of Orthopedic Surgery, Maastricht University, Maastricht, The Netherlands
| | - Andy Cremers
- Laboratory for Experimental Orthopedics, Department of Orthopedic Surgery, Maastricht University, Maastricht, The Netherlands
| | - Donatus A M Surtel
- Laboratory for Experimental Orthopedics, Department of Orthopedic Surgery, Maastricht University, Maastricht, The Netherlands
| | - Willem Voncken
- Department of Molecular Genetics, Maastricht University, Maastricht, The Netherlands
| | - Tim J M Welting
- Laboratory for Experimental Orthopedics, Department of Orthopedic Surgery, Maastricht University, Maastricht, The Netherlands.
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43
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Zhou M, Werbner B, O'Connell GD. Fiber engagement accounts for geometry-dependent annulus fibrosus mechanics: A multiscale, Structure-Based Finite Element Study. J Mech Behav Biomed Mater 2020; 115:104292. [PMID: 33453608 DOI: 10.1016/j.jmbbm.2020.104292] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 12/10/2020] [Accepted: 12/21/2020] [Indexed: 02/04/2023]
Abstract
A comprehensive understanding of biological tissue mechanics is crucial for designing engineered tissues that aim to recapitulate native tissue behavior. Tensile mechanics of many fiber-reinforced tissues have been shown to depend on specimen geometry, which makes it challenging to compare data between studies. In this study, a validated multiscale, structure-based finite element model was used to evaluate the effect of specimen geometry on multiscale annulus fibrosus tensile mechanics through a fiber engagement analysis. The relationships between specimen geometry and modulus, Poisson's ratio, tissue stress-strain distributions, and fiber reorientation behaviors were investigated at both tissue and sub-tissue levels. It was observed that annulus fibrosus tissue level tensile properties and stress transmission mechanisms were dependent on specimen geometry. The model also demonstrated that the contribution of fiber-matrix interactions to tissue mechanical response was specimen size- and orientation-dependent. The results of this study reinforce the benefits of structure-based finite element modeling in studies investigating multiscale tissue mechanics. This approach also provides guidelines for developing optimal combined computational-experimental study designs for investigating fiber-reinforced biological tissue mechanics. Additionally, findings from this study help explain the geometry dependence of annulus fibrosus tensile mechanics previously reported in the literature, providing a more fundamental and comprehensive understanding of tissue mechanical behavior. In conclusion, the methods presented here can be used in conjunction with experimental tissue level data to simultaneously investigate tissue and sub-tissue scale mechanics, which is important as the field of soft tissue biomechanics advances toward studies that focus on diminishing length scales.
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Affiliation(s)
- Minhao Zhou
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Benjamin Werbner
- Department of Mechanical Engineering, University of California, Berkeley, USA
| | - Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, USA; Department of Orthopaedic Surgery, University of California, San Francisco, USA.
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Sun Z, Zhao H, Liu B, Gao Y, Tang WH, Liu ZH, Luo ZJ. AF cell derived exosomes regulate endothelial cell migration and inflammation: Implications for vascularization in intervertebral disc degeneration. Life Sci 2020; 265:118778. [PMID: 33217442 DOI: 10.1016/j.lfs.2020.118778] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/01/2020] [Accepted: 11/14/2020] [Indexed: 12/19/2022]
Abstract
AIMS The intervertebral disc is the largest avascular organ of the body. Vascularization of the disc has been typically regarded as a pathological feature of intervertebral disc degeneration (IDD). However, the underlying mechanism of vascularization in IDD is still unclear. The current study aimed to investigate the role of AF cell derived exosome (AF-exo) in the interaction with human umbilical vein endothelial cells (HUVECs) and its potential role in the regulation of vascularization in IDD. MAIN METHODS Human AF tissues were obtained from patients with IDD and idiopathic scoliosis. The AF-exo were isolated and identified by transmission electron microscopy (TEM), nanoparticle trafficking analysis (NTA) and Western blotting. Then, the AF-exo were used for HUVECs cultures. The migration of HUVECs was observed in 2D and 3D cultures. The inflammatory phenotype of HUVECs was examined by Real-time PCR and enzyme-linked immunosorbent assay (ELISA). Additionally, apoptosis of HUVECs were analyzed by flow cytometry. KEY FINDINGS Here, we for the first time found that AF cells could secrete AF-exo and that the AF-exo could be phagocytosed by HUVECs. Additionally, we found that degenerated AF-exo exerted pro-vascularization effect on HUVECs by promoting cell migration (in 2D and 3D cultures) and inflammatory factor expression including IL-6, TNF-α, MMP-3, MMP-13 and VEGF, whereas the application of non-degenerated AF-exo demonstrated inverse effects. SIGNIFICANCE These results showed that AF-exo is an essential regulator mediating intercellular communication between AF cells and HUVECs, suggesting its important role in vascularization in the intervertebral disc.
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Affiliation(s)
- Zhen Sun
- Department of Orthopedic, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China.
| | - Hang Zhao
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China; Department of Pharmacy, The 456th Hospital of the People's Liberation Army, Jinan, PR China
| | - Bing Liu
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China
| | - Yang Gao
- Department of Orthopedic, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China
| | - Wen-Hao Tang
- Department of Orthopedic, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China
| | - Zhi-Heng Liu
- Department of Orthopedic, 986 Air Force Hospital of China, Xi'an, Shaanxi Province, PR China
| | - Zhuo-Jing Luo
- Department of Orthopedic, Xijing Hospital, Fourth Military Medical University, Western Changle Road, Xi'an, Shaanxi Province, PR China.
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Tsingas M, Ottone OK, Haseeb A, Barve RA, Shapiro IM, Lefebvre V, Risbud MV. Sox9 deletion causes severe intervertebral disc degeneration characterized by apoptosis, matrix remodeling, and compartment-specific transcriptomic changes. Matrix Biol 2020; 94:110-133. [PMID: 33027692 DOI: 10.1016/j.matbio.2020.09.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 12/27/2022]
Abstract
SOX9 plays an important role in chondrocyte differentiation and, in the developing axial skeleton, maintains the notochord and the demarcation of intervertebral disc compartments. Diminished expression is linked to campomelic dysplasia, resulting in severe scoliosis and progressive disc degeneration. However, the specific functions of SOX9 in the adult spinal column and disc are largely unknown. Accordingly, employing a strategy to conditionally delete Sox9 in Acan-expressing cells (AcanCreERT2Sox9fl/fl), we delineated these functions in the adult intervertebral disc. AcanCreERT2Sox9fl/fl mice (Sox9cKO) showed extensive and progressive remodeling of the extracellular matrix in nucleus pulposus (NP) and annulus fibrosus (AF), consistent with human disc degeneration. Progressive degeneration of the cartilaginous endplates (EP) was also evident in Sox9cKO mice, and it preceded morphological changes seen in the NP and AF compartments. Fate mapping using tdTomato reporter, EdU chase, and quantitative immunohistological studies demonstrated that SOX9 is crucial for disc cell survival and phenotype maintenance. Microarray analysis showed that Sox9 regulated distinct compartment-specific transcriptomic landscapes, with prominent contributions to the ECM, cytoskeleton-related, and metabolic pathways in the NP and ion transport, the cell cycle, and signaling pathways in the AF. In summary, our work provides new insights into disc degeneration in Sox9cKO mice at the cellular, molecular, and transcriptional levels, underscoring tissue-specific roles of this transcription factor. Our findings may direct future cell therapies targeting SOX9 to mitigate disc degeneration.
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Affiliation(s)
- Maria Tsingas
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Olivia K Ottone
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Abdul Haseeb
- Department of Surgery/Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ruteja A Barve
- Department of Genetics, Genome Technology Access Centre at the McDonnell Genome Institute, Washington University, School of Medicine, St. Louis, MO 63110, USA
| | - Irving M Shapiro
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Véronique Lefebvre
- Department of Surgery/Division of Orthopaedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Makarand V Risbud
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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DiStefano TJ, Shmukler JO, Danias G, Di Pauli von Treuheim T, Hom WW, Goldberg DA, Laudier DM, Nasser PR, Hecht AC, Nicoll SB, Iatridis JC. Development of a two-part biomaterial adhesive strategy for annulus fibrosus repair and ex vivo evaluation of implant herniation risk. Biomaterials 2020; 258:120309. [PMID: 32823020 DOI: 10.1016/j.biomaterials.2020.120309] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022]
Abstract
Intervertebral disc (IVD) herniation causes pain and disability, but current discectomy procedures alleviate pain without repairing annulus fibrosus (AF) defects. Tissue engineering strategies seal AF defects by utilizing hydrogel systems to prevent recurrent herniation, however current biomaterials are limited by poor adhesion to wetted tissue surfaces or low failure strength resulting in considerable risk of implant herniation upon spinal loading. Here, we developed a two-part repair strategy comprising a dual-modified (oxidized and methacrylated) glycosaminoglycan that can chemically adsorb an injectable interpenetrating network hydrogel composed of fibronectin-conjugated fibrin and poly (ethylene glycol) diacrylate (PEGDA) to covalently bond the hydrogel to AF tissue. We show that dual-modified hyaluronic acid imparts greater adhesion to AF tissue than dual-modified chondroitin sulfate, where the degree of oxidation is more strongly correlated with adhesion strength than methacrylation. We apply this strategy to an ex vivo bovine model of discectomy and demonstrate that PEGDA molecular weight tunes hydrogel mechanical properties and affects herniation risk, where IVDs repaired with low-modulus hydrogels composed of 20kDa PEGDA failed at levels at or exceeding discectomy, the clinical standard of care. This strategy bonds injectable hydrogels to IVD extracellular matrix proteins, is optimized to seal AF defects, and shows promise for IVD repair.
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Affiliation(s)
- Tyler J DiStefano
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jennifer O Shmukler
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George Danias
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Warren W Hom
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - David A Goldberg
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Damien M Laudier
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Philip R Nasser
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Andrew C Hecht
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steven B Nicoll
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - James C Iatridis
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Derrouiche A, Zaouali A, Zaïri F, Ismail J, Qu Z, Chaabane M, Zaïri F. Osmo-inelastic response of the intervertebral disc annulus fibrosus tissue. Proc Inst Mech Eng H 2020; 234:1000-1010. [PMID: 32615851 DOI: 10.1177/0954411920936047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this article is to provide some insights on the osmo-inelastic response under stretching of annulus fibrosus of the intervertebral disc. Circumferentially oriented specimens of square cross section, extracted from different regions of bovine cervical discs (ventral-lateral and dorsal-lateral), are tested under different strain-rates and saline concentrations within normal range of strains. An accurate optical strain measuring technique, based upon digital image correlation, is used in order to determine the full-field displacements in the lamellae and fibers planes of the layered soft tissue. Annulus stress-stretch relationships are measured along with full-field transversal strains in the two planes. The mechanical response is found hysteretic, rate-dependent and osmolarity-dependent with a Poisson's ratio higher than 0.5 in the fibers plane and negative (auxeticity) in the lamellae plane. While the stiffness presents a regional-dependency due to variations in collagen fibers content/orientation, the strain-rate sensitivity of the response is found independent on the region. A significant osmotic effect is found on both the auxetic response in the lamellae plane and the stiffness rate-sensitivity. These local experimental observations will result in more accurate chemo-mechanical modeling of the disc annulus and a clearer multi-scale understanding of the disc intervertebral function.
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Affiliation(s)
- Amil Derrouiche
- Civil Engineering and geo-Environmental Laboratory (ULR 4515 LGCgE), Lille University, Lille, France
| | - Ameni Zaouali
- Mechanical Engineering Laboratory, ENIM, Monastir University, Monastir, Tunisia
| | - Fahmi Zaïri
- Civil Engineering and geo-Environmental Laboratory (ULR 4515 LGCgE), Lille University, Lille, France
| | - Jewan Ismail
- Civil Engineering and geo-Environmental Laboratory (ULR 4515 LGCgE), Lille University, Lille, France
| | - Zhengwei Qu
- Civil Engineering and geo-Environmental Laboratory (ULR 4515 LGCgE), Lille University, Lille, France
| | - Makram Chaabane
- Mechanical Engineering Laboratory, ENIM, Monastir University, Monastir, Tunisia
| | - Fahed Zaïri
- Hôpital privé Le Bois, Ramsay Générale de Santé, Lille, France
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48
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Zwambag DP, Molladavoodi S, Guerreiro MJ, DeWitte-Orr SJ, Gregory DE. Immuno-stimulatory capacity of decorin in the rat tail intervertebral disc and the mechanical consequence of resultant inflammation. Eur Spine J 2020; 29:1641-1648. [PMID: 32451779 DOI: 10.1007/s00586-020-06469-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/27/2020] [Accepted: 05/14/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE Determine whether decorin is immuno-stimulatory to rat tail IVD cells and to characterize the mechanical consequence of inflammation at the whole rat tail IVD level. METHODS Cultured rat tail annulus fibrosus (AF) cells were exposed to decorin, a resident IVD small leucine-rich proteoglycan (SLRP), with and without the presence of a toll-like receptor (TLR) 4 inhibitor, TAK-242. Resultant expression of pro-inflammatory cytokine and chemokines (MCP-1; MIP-2; RANTES; IL-6; TNFα) were quantified over 24 h. Whole rat tail IVD cultures (n = 50) were also treated with decorin (two concentrations: 0.5 and 5.0 μg/mL) with and without TAK-242 (via nucleus pulpous injection with a 33-gauge needle), and resultant mechanical properties were measured. RESULTS AF cells exposed to decorin showed significant increases in pro-inflammatory cytokine and chemokine production; this was significantly blunted with the presence of TAK-242. Whole IVDs injected with decorin showed a dose-dependent decrease in neutral zone and tensile stiffness and an increase in neutral zone size. When TAK-242 was injected into the IVD with the decorin, mechanical stiffness was preserved and not different from sham controls (injected with PBS). CONCLUSION AF cells are capable of detecting decorin and inducing inflammation. Decorin further resulted in a functional deterioration in IVD mechanical integrity. TAK- 242, a TLR4 inhibitor, blunted chemokine production at the cellular level and preserved mechanical stiffness in the whole IVD.
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Affiliation(s)
- Derek P Zwambag
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON, N2L 3C5, Canada
| | - Sara Molladavoodi
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON, N2L 3C5, Canada
| | - Matthew J Guerreiro
- Department of Integrative Biology, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Stephanie J DeWitte-Orr
- Department of Integrative Biology, Wilfrid Laurier University, Waterloo, ON, Canada.,Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Diane E Gregory
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON, N2L 3C5, Canada. .,Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada.
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49
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Fewster KM, Noguchi M, Gooyers CE, Wong A, Callaghan JP. Exploring the regional disc bulge response of the cervical porcine intervertebral disc under varying loads and posture. J Biomech 2020; 104:109713. [PMID: 32139100 DOI: 10.1016/j.jbiomech.2020.109713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/01/2020] [Accepted: 02/18/2020] [Indexed: 11/24/2022]
Abstract
Nerve compression due to intervertebral disc (IVD) bulging is a known mechanism for low back pain and typically occurs in the posterior region of the disc. Most in vitro studies are limited in the ability to quantify the magnitude of bulging on the posterior aspect of the disc due to the boney structures that occlude a direct line-of-sight in the intact functional spinal units (FSUs). This study examined anterior and posterior annulus fibrosus (AF) bulges in reduced (posterior elements removed) cervical porcine specimens across four loading conditions and two postures. Surface scans from the anterior and posterior aspect of the IVD were recorded in both neutral and flexed postures using a 3D laser scanner to characterize changes in AF bulge. A significant negative correlation was observed for peak AF bulge on the anterior and posterior side of the disc in a flexed posture (Pearson's r = -0.448; p = 0.002; r2 = 0.2003). The results from this investigation support that there may be a connection between the magnitude of AF bulge on the posterior side and estimations computed using the anterior side.
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Affiliation(s)
- Kayla M Fewster
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Mamiko Noguchi
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Chad E Gooyers
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada; Department of Systems, 30 Forensic Engineering, Toronto, Ontario, Canada
| | - Alexander Wong
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
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50
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Ohnishi T, Novais EJ, Risbud MV. Alterations in ECM signature underscore multiple sub-phenotypes of intervertebral disc degeneration. Matrix Biol Plus 2020; 6-7:100036. [PMID: 33543030 PMCID: PMC7852332 DOI: 10.1016/j.mbplus.2020.100036] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 12/18/2022] Open
Abstract
The intervertebral disc is a specialized connective tissue critical for absorption of mechanical loads and providing flexibility to the spinal column. The disc ECM is complex and plays a vital role in imparting tissue its biomechanical function. The central NP is primarily composed of large aggregating proteoglycans (PGs) while surrounding AF is composed of fibrillar collagens, I and II. Aggrecan and versican in particular, due to their high concentration of sulfated GAG chains form large aggregates with hyaluronic acid (HA) and provide water binding capacity to the disc. Degradation of aggrecan core protein due to aggrecanase and MMP activity, SNPs that affect number of chondroitin sulfate (CS) substitutions and alteration in enzymes critical in synthesis of CS chains can impair the aggrecan functionality. Similarly, levels of many matrix and matrix-related molecules e.g. Col2, Col9, HAS2, ccn2 are dysregulated during disc degeneration and genetic animal models have helped establish causative link between their expression and disc health. In the degenerating and herniated discs, increased levels of inflammatory cytokines such as TNF-α, IL-1β and IL-6 are shown to promote matrix degradation through regulating expression and activity of critical proteases and stimulate immune cell activation. Recent studies of different mouse strains have better elucidated the broader impact of spontaneous degeneration on disc matrix homeostasis. SM/J mice showed an increased cell apoptosis, loss of cell phenotype, and cleavage of aggrecan during early stages followed by tissue fibrosis evident by enrichment of several collagens, SLRPs and fibronectin. In summary, while disc degeneration encompasses wide spectrum of degenerative phenotypes extensive matrix degradation and remodeling underscores all of them. The intervertebral disc absorbs loads and provides flexibility to the spine. The ECM is complex and vital for imparting tissue its biomechanical function. Numerous types of proteoglycans and collagens designate the quality of the disc. Many matrix and matrix-related molecules are dysregulated during disc degeneration. Matrix degradation and remodeling underscores wide spectrum of phenotype.
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Affiliation(s)
- Takashi Ohnishi
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Emanuel J Novais
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Makarand V Risbud
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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