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Suh HR, Cho HY, Han HC. Development of a novel model of intervertebral disc degeneration by the intradiscal application of monosodium iodoacetate (MIA) in rat. Spine J 2022; 22:183-192. [PMID: 34118415 DOI: 10.1016/j.spinee.2021.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Low back pain is one of the most common musculoskeletal disorders. Although, the pathology of intervertebral disc (IVD) degeneration has been modeled using various biological methods, these models are inadequate for simulating similar pathologic states in humans. PURPOSE This study investigated whether monosodium iodoacetate (MIA) injection into the IVD of rats could generate a reliable model of IVD degeneration. STUDY DESIGN/SETTINGS In vivo animal study. METHODS MIA was injected into two-disc spaces (L4-5 and L5-6) of Sprague-Dawley rats. Their behaviors were examined by measuring weight load shifts from hind to forefoot, rearing, and von Frey tests. We examined the inhibition of pain behavior through intraperitoneal morphine injection and measured cyclooxygenase-2 (COX-2) and transcription factor nuclear factor-kappa B (NF-κB) levels in the IVD and dorsal root ganglion (DRG) by Western blot. Bone alterations were assessed by microfocus computed tomography (micro-CT), and IVD and/or cartilage changes were evaluated by hematoxylin and eosin and safranin-O staining and inducible nitric oxide synthase (iNOS) immunohistochemistry. The other authors declare no conflicts of interest. This project funded by the Memorial Fund and the National Research Foundation of Korea (NRF). RESULTS We observed increased weight load shifts to the forefoot and decreased rearing. Morphine-injected rats showed reduced pain. NF-κB and COX-2 expression increased in the IVD and left and/or right DRG. Micro-CT analyses suggested progressive bone deformation. Histologic examination showed decreased IVD width and nucleus pulposus area. Cartilaginous changes indicated epiphyseal growth plate loss. Finally, iNOS expression was increased in the subchondral endplate. CONCLUSIONS These results suggest that low back pain (LBP) models can be developed by MIA injection into the IVDs of rats and that an animal model is useful for exploring degenerative alterations in the affected discs. Therefore, MIA injection may be a useful model for the study of changes in the IVD to elucidate the mechanisms underlying clinical symptoms, such as LBP, in patients with IVD degeneration. CLINICAL SIGNIFICANCE This model in which MIA was injected into the disc better represented the human histologic and behavioral characteristics than the existing puncture model.
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Affiliation(s)
- Hye Rim Suh
- Department of Physiology, Korea University, Seoul, Republic of Korea
| | - Hwi-Young Cho
- Department of Physical Therapy, Gachon University, Incheon, Republic of Korea.
| | - Hee Chul Han
- Department of Physiology, Korea University, Seoul, Republic of Korea.
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2
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Xing Y, Zhang P, Zhang Y, Holzer L, Xiao L, He Y, Majumdar R, Huo J, Yu X, Ramasubramanian MK, Jin L, Wang Y, Li X, Oberholzer J. A multi-throughput mechanical loading system for mouse intervertebral disc. J Mech Behav Biomed Mater 2020; 105:103636. [PMID: 32279855 DOI: 10.1016/j.jmbbm.2020.103636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 12/01/2022]
Abstract
Mechanical loading plays an important role in maintaining disc health and function, and in particular, excessive mechanical loading has been identified as one of major reasons of disc degeneration. Intervertebral disc organ culture serves as a valuable tool to study disc biology/pathology. In this study, we report the development and validation of a new mouse disc organ culture system by dynamically applying compression loading in a customized micro-culture device tailored for mouse lumbar discs. Precise axial compression force was delivered by a computer-controlled system consisting of a robust micromechanical linear actuator, a force sensitive resistor, and a precision micro-stepping machinery. Customized PDMS-based loading chambers allowed simultaneous loading of six discs per regimen, which streamlined the workflow to reach sufficient statistic power. The detrimental loading regimen of mouse lumbar discs (0.5 MPa of axial compression at 1Hz for 7 days) was demonstrated through live-dead assay, histology, and fluorescence probe based collagen staining. In addition, various mechanical compression profiles were simulated using different materials and geometry designs, potentiating for more sophisticated loading protocols. In summary, we developed a new mechanical loading system for dynamic axial compression of mouse discs, which created a unique avenue to study disc pathogenesis with enriched mouse species-related resources, and complemented the existing spectrum of bioreactor systems predominately for discs of human and large animals.
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Affiliation(s)
- Yuan Xing
- Department of Surgery, University of Virginia, 345 Crispell Drive, Charlottesville, VA, 22908, United States
| | - Pu Zhang
- Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA, 22904, United States
| | - Yangpu Zhang
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States; Current Address: Department of Orthopedic Surgery, Beijing Chaoyang Hospital, Capital Medical University, Chaoyang District, Beijing, China
| | - Liam Holzer
- Department of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, United States
| | - Li Xiao
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States
| | - Yi He
- Department of Surgery, University of Virginia, 345 Crispell Drive, Charlottesville, VA, 22908, United States
| | - Rahul Majumdar
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States
| | - Jianzhong Huo
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States; Current Address: Department of Orthopaedic Surgery, Shanxi DaYi Hospital, 99 Long Road, Taiyuan, Shanxi, 030032, China
| | - Xiaoyu Yu
- Department of Surgery, University of Virginia, 345 Crispell Drive, Charlottesville, VA, 22908, United States
| | - Melur K Ramasubramanian
- Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA, 22904, United States
| | - Li Jin
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States
| | - Yong Wang
- Department of Surgery, University of Virginia, 345 Crispell Drive, Charlottesville, VA, 22908, United States
| | - Xudong Li
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, VA, 22908, United States.
| | - Jose Oberholzer
- Department of Surgery, University of Virginia, 345 Crispell Drive, Charlottesville, VA, 22908, United States.
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Dai J, Xing Y, Xiao L, Li J, Cao R, He Y, Fang H, Periasamy A, Oberhozler J, Jin L, Landers JP, Wang Y, Li X. Microfluidic Disc-on-a-Chip Device for Mouse Intervertebral Disc-Pitching a Next-Generation Research Platform To Study Disc Degeneration. ACS Biomater Sci Eng 2019; 5:2041-2051. [PMID: 31763444 DOI: 10.1021/acsbiomaterials.8b01522] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Low back pain is the most common cause of disability worldwide, and intervertebral disc degeneration is a major cause of low back pain. Unfortunately, discogenic low back pain is often treated with symptomatic relief interventions, as no disease-modifying medications are yet available. Both to-be-deciphered disc biology/pathology and inadequate in vitro research platform are major hurdles limiting drug discovery progress for disc degeneration. Here, we developed a microfluidic disc-on-a-chip device tailored for mouse disc organ as an in vitro research platform. We hypothesize that continuous nutrients empowered by a microfluidic device would improve biological performance of cultured mouse discs compared to those in static condition. This device permitted continuous media flow to mimic in vivo disc microenvironment. Intriguingly, mouse discs cultured on the microfluidic device exhibited much higher cell viability, better preserved structure integrity and anabolic-catabolic metabolism in both nucleus pulposus and annulus fibrosus, for up to 21 days compared to those in static culture. This first "disc-on-a-chip" device lays groundwork for future preclinical studies in a relative long-term organ culture given the chronic nature of intervertebral disc degeneration. In addition, this platform is readily transformable into a streamlined in vitro research platform to recapitulate physiological and pathophysiological microenvironment to accelerate disc research.
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Affiliation(s)
- Jun Dai
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, Virginia 22908, United States.,Department of Orthopaedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue Qiaokou District, Wuhan 430030, P.R. China
| | - Yuan Xing
- Department of Surgery, University of Virginia, 345 Cripell Drive, Charlottesville, Virginia 22908, United States
| | - Li Xiao
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, Virginia 22908, United States
| | - Jingyi Li
- ∥ Department of Chemistry, University of Virginia, 409 McCormick Road, Charlottesville, Virginia 22904, United States
| | - Ruofan Cao
- W.M. Keck Center for Cellular Imaging, University of Virginia, 90 Geldard Drive, Charlottesville, Virginia 22904, United States
| | - Yi He
- Department of Surgery, University of Virginia, 345 Cripell Drive, Charlottesville, Virginia 22908, United States
| | - Huang Fang
- Department of Orthopaedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue Qiaokou District, Wuhan 430030, P.R. China
| | - Ammasi Periasamy
- W.M. Keck Center for Cellular Imaging, University of Virginia, 90 Geldard Drive, Charlottesville, Virginia 22904, United States
| | - Jose Oberhozler
- Department of Surgery, University of Virginia, 345 Cripell Drive, Charlottesville, Virginia 22908, United States
| | - Li Jin
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, Virginia 22908, United States
| | - James P Landers
- ∥ Department of Chemistry, University of Virginia, 409 McCormick Road, Charlottesville, Virginia 22904, United States.,Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, Virginia 22904, United States.,Department of Pathology, University of Virginia, 415 Lane Road, Charlottesville, Virginia 22908, United States
| | - Yong Wang
- Department of Surgery, University of Virginia, 345 Cripell Drive, Charlottesville, Virginia 22908, United States
| | - Xudong Li
- Department of Orthopaedic Surgery, University of Virginia, 135 Hospital Drive, Charlottesville, Virginia 22908, United States.,Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, Virginia 22908, United States
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Chen Q, Shi F, Yang X, Liu L, Song Y. [Comparative study on biological characteristics between different generations of rabbit nucleus pulposus cells]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2018; 32:660-667. [PMID: 29905041 DOI: 10.7507/1002-1892.201707017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Objective To research the biological characteristics of different generations of rabbit nucleus pulposus cells (NPCs) that were cultured with natural culture and subculture method. Methods The thoracolumbar segments of New Zealand white rabbits (6-8 weeks old and weighing 1.5-2.5 kg) were obtained and nucleus pulposus were isolated from disc regions. And NPCs were harvested by enzymatic digestion from nucleus pulposus. Primary NPCs were counted as P0 generation. Then, NPCs were passaged by trypsin and counted as P1, P2, P3 with a totle of 4 generations. P0 to P3 generations NPCs were separately examined by observation of cell morphology and proliferation time, detection of apoptosis rates of cells by flow cytometry, and detection of hypoxia-inducible factor 1α (HIF-1α), matrix metalloproteinases 2 (MMP-2), Aggrecan, and collagen type Ⅱ proteins by immunofluorescence and Western blot. Results The morphology of NPCs transformed from triangular or polygonal in P0 generation to spindle in P3 generation; the characteristic vacuolated cells gradually disappeared; and the cell volume and cell proliferation time increased. The cell apoptosis rates were 5.47%±0.91%, 13.77%±2.42%, 33.46%±1.82%, and 38.76%±1.50% from P0 to P3 generations, with the increase of culture time, and there were significant differences between 4 generations ( P<0.05). Immunofluorescence staining showed that with the increase of cells generation, the fluorescence intensity of HIF-1α, collagen type Ⅱ, and Aggrecan decreased, and the fluorescence intensity of MMP-2 increased. Western blot results showed that the relative expression of HIF-1α protein was high in P0 generation, the P1 generation has a rising trend, and then gradually decreased; the differences between generations were significant ( P<0.05). The relative expression of collagen type Ⅱ protein decreased from P0 to P3 generations and there were significant differences between generations ( P<0.05). The relative expression of Aggrecan protein decreased from P0 to P2 generations and there were significant differences between generations ( P<0.05); but no significant difference was found between P2 and P3 generations ( P>0.05). The relative expression of MMP-2 protein increased significantly in P3 generation; except that the difference between P0 and P2 generations was not significant ( P>0.05), the significant differences were found between the other generations ( P<0.05). Conclusion Rabbit NPCs degeneration model was successfully established by the natural culture and subculture method. Transforming of NPCs morphology, increasing of cell apoptosis rates, decreasing of anabolism, and increasing of catabolism were presented in NPCs degeneration model.
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Affiliation(s)
- Qi Chen
- Department of Orthopedics, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou Zhejiang, 310014, P.R.China;Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Fangfang Shi
- Department of Hematology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou Zhejiang, 310014, P.R.China
| | - Xi Yang
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Limin Liu
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Yueming Song
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041,
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Zvicer J, Obradovic B. Bioreactors with hydrostatic pressures imitating physiological environments in intervertebral discs. J Tissue Eng Regen Med 2017; 12:529-545. [PMID: 28763577 DOI: 10.1002/term.2533] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 06/27/2017] [Accepted: 07/27/2017] [Indexed: 12/28/2022]
Abstract
Intervertebral discs are normally exposed to a variety of loads and stresses but hydrostatic pressure (HP) could be the main biosignal for chondrogenic cell differentiation and maintenance of this tissue. Although there are simple approaches to intermittently expose cell cultures to HP in separate material testing devices, utilization of biomimetic bioreactors aiming to provide in vitro conditions mimicking those found in vivo, attracts special attention. However, design of such bioreactors is complex due to the requirement of high HP magnitudes (up to 3 MPa) applied in different regimes mimicking pressures arising in intervertebral disc during normal daily activities. Furthermore, efficient mass transfer has to be facilitated to cells within 3D scaffolds, and the engineering challenges include avoidance or removal of gas bubbles in the culture medium before pressurization as well as selection of appropriate, biocompatible construction materials and maintenance of sterility during cultivation. Here, we review approaches to induce HP in 2D and 3D cell cultures categorized into 5 groups: (I) discontinuous systems with direct pressurization of the cultivation medium by a piston, (II) discontinuous systems with indirect pressurization by a compression fluid, (III) continuous systems with direct pressurization of the cultivation medium, static culture, (IV) continuous systems with culture perfusion, and (V) systems applying HP in conjunction with other physical signals. Although the complexity is increasing as additional features are added to the systems, the need to understand HP effects on cells and tissues in a physiologically relevant, yet precisely controlled, environment together with current technological advancements are leading towards innovative bioreactor solutions.
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Affiliation(s)
- Jovana Zvicer
- Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
| | - Bojana Obradovic
- Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
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Functional impact of integrin α5β1 on the homeostasis of intervertebral discs: a study of mechanotransduction pathways using a novel dynamic loading organ culture system. Spine J 2015; 15:417-26. [PMID: 25546513 PMCID: PMC5673479 DOI: 10.1016/j.spinee.2014.12.143] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 12/09/2014] [Accepted: 12/19/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Intervertebral disc (IVD) degeneration, a major cause of low back pain, is considered to be induced by daily mechanical loading. Mechanical stress is widely known to affect cell survival and extracellular matrix metabolism in many cell types. Although the involvement of integrin α5β1 transmembrane mechanoreceptor in IVD degeneration has been reported, the precise function of integrin α5β1 remains obscure. PURPOSE To reflect IVD tissue response to mechanical stress using a dynamic loading organ culture system and elucidate the functional impact of integrin α5β1 on the pathomechanism of IVD degeneration. STUDY DESIGN An ex vivo study using a dynamic loading organ culture system. METHODS Ninety-six rat IVD explants were examined. Intervertebral discs were subjected to 1.3 MPa, 1.0 Hz dynamic compressive load in the presence or absence of an Arg-Gly-Asp (RGD) peptide with affinity to the fibronectin binding-site of integrin α5β1. Cell viability and histomorphology were assessed. The localization of integrin α5β1 in the IVD was assessed by immunohistochemistry. Gene expression levels of IVD cells were evaluated using real-time reverse transcription-polymerase chain reaction. RESULTS In the nucleus pulposus (NP), cell density and viability were reduced by dynamic compressive load. Histologic degenerative alterations, mainly seen in the NP, were the morphologic changes of NP cells. In both NP and annulus fibrosus (AF), immunohistochemistry revealed localization of integrin α5β1 and that the messenger-RNA expression of integrin α5β1 was increased by dynamic load. Dynamic load induced a catabolic effect, the stimulation of matrix metalloproteinase-3 and -13 gene expressions by NP and AF cells. The RGD peptide partially blocked the histologic alterations and the catabolic effect. CONCLUSIONS The dynamic loading organ culture system simulated cellular responses to mechanical loading of the IVD. Our results suggest that IVD cells recognize the mechanical stress through RGD integrins, particularly the α5β1 subtype that is highly expressed in NP and AF cells. Further experiments using this system will provide information about pathomechanisms of IVD degeneration through the mechanotransduction pathways.
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Dynamic pressurization induces transition of notochordal cells to a mature phenotype while retaining production of important patterning ligands from development. Arthritis Res Ther 2014; 15:R122. [PMID: 24427812 PMCID: PMC3978427 DOI: 10.1186/ar4302] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Introduction Notochordal cells (NCs) pattern aneural and avascular intervertebral discs (IVDs), and their disappearance, is associated with onset of IVD degeneration. This study induced and characterized the maturation of nucleus pulposus (NP) tissue from a gelatinous NC-rich structure to a matrix-rich structure populated by small NP cells using dynamic pressurization in an ex vivo culture model, and also identified soluble factors from NCs with therapeutic potential. Methods Porcine NC-rich NP tissue was cultured and loaded with hydrostatic pressure (0.5 to 2 MPa at 0.1 Hz for 2 hours) either Daily, for 1 Dose, or Control (no pressurization) groups for up to eight days. Cell phenotype and tissue maturation was characterized with measurements of cell viability, cytomorphology, nitric oxide, metabolic activity, matrix composition, gene expression, and proteomics. Results Daily pressurization induced transition of NCs to small NP cells with 73.8%, 44%, and 28% NCs for Control, 1 Dose and Daily groups, respectively (P < 0.0002) and no relevant cell death. Dynamic loading matured NP tissue by significantly increasing metabolic activity and accumulating Safranin-O-stained matrix. Load-induced maturation was also apparent from the significantly decreased glycolytic, cytoskeletal (Vimentin) and stress-inducible (HSP70) proteins assessed with proteomics. Loading increased the production of bioactive proteins Sonic Hedgehog (SHH) and Noggin, and maintained Semaphorin3A (Sema3A). Discussion NP tissue maturation was induced from dynamic hydrostatic pressurization in a controlled ex vivo environment without influence from systemic effects or surrounding structures. NCs transitioned into small nonvacuolated NP cells probably via differentiation as evidenced by high cell viability, lack of nitric oxide and downregulation of stress-inducible and cytoskeletal proteins. SHH, Sema3A, and Noggin, which have patterning and neurovascular-inhibiting properties, were produced in both notochordal and matured porcine NP. Results therefore provide an important piece of evidence suggesting the transition of NCs to small NP cells is a natural part of aging and not the initiation of degeneration. Bioactive candidates identified from young porcine IVDs may be isolated and harnessed for therapies to target discogenic back pain.
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Assessment of the matrix degenerative effects of MMP-3, ADAMTS-4, and HTRA1, injected into a bovine intervertebral disc organ culture model. Spine (Phila Pa 1976) 2013; 38:E1377-87. [PMID: 23778376 DOI: 10.1097/brs.0b013e31829ffde8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN In vitro study to develop an intervertebral disc degeneration organ culture model, using coccygeal bovine intervertebral discs (IVDs) and injection of proteolytic enzymes MMP-3, ADAMTS-4, and HTRA1. OBJECTIVE This study aimed to develop an in vitro model of enzyme-mediated intervertebral disc degeneration to mimic the clinical outcome in humans for investigation of therapeutic treatment options. SUMMARY OF BACKGROUND DATA Bovine IVDs are comparable with human IVDs in terms of cell composition and biomechanical behavior. Researchers injected papain and trypsin into them to create an intervertebral disc degeneration model with a degenerated nucleus pulposus (NP) area. They achieved macroscopic cavities as well as a loss of glycosaminoglycans (GAGs). However, none of these enzymes are clinically relevant. METHODS Bovine IVDs were harvested maintaining the endplates. Active forms of MMP-3, ADAMTS-4, and HTRA1 were injected at a dose of 10 μg/mL each. Phosphate-buffered saline was injected as a control. Discs were cultured for 8 days and loaded diurnally (days 1-4 with ≈0.4 MPa for 16 hr) and left under free swelling condition from days 4 to 8 to avoid expected artifacts because of dehydration of the NP. Outcome parameters included disc height, metabolic cell activity, DNA content, GAG content, total collagen content, relative gene expression, and histological investigation. RESULTS The mean metabolic cell activity was significantly lower in the NP area of discs injected with ADAMTS-4 than the day 0 control discs. Disc height was decreased after injection with HTRA1 and was significantly correlated with changes in GAG/DNA of the NP tissue. Total collagen content tended to be lower in groups injected with ADAMTS4 and MMP-3. CONCLUSION MMP-3, ADAMTS-4, and HTRA1 provoked neither visible matrix degradation nor major shifts in gene expression. However, cell activity was significantly reduced and HTRA1 induced loss of disc height that positively correlated with changes in GAG/DNA content. The use of higher doses of these enzymes or a combination thereof may, therefore, be necessary to induce disc degeneration.
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Paul CPL, Zuiderbaan HA, Zandieh Doulabi B, van der Veen AJ, van de Ven PM, Smit TH, Helder MN, van Royen BJ, Mullender MG. Simulated-physiological loading conditions preserve biological and mechanical properties of caprine lumbar intervertebral discs in ex vivo culture. PLoS One 2012; 7:e33147. [PMID: 22427972 PMCID: PMC3302815 DOI: 10.1371/journal.pone.0033147] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 02/09/2012] [Indexed: 01/07/2023] Open
Abstract
Low-back pain (LBP) is a common medical complaint and associated with high societal costs. Degeneration of the intervertebral disc (IVD) is assumed to be an important causal factor of LBP. IVDs are continuously mechanically loaded and both positive and negative effects have been attributed to different loading conditions. In order to study mechanical loading effects, degeneration-associated processes and/or potential regenerative therapies in IVDs, it is imperative to maintain the IVDs' structural integrity. While in vivo models provide comprehensive insight in IVD biology, an accompanying organ culture model can focus on a single factor, such as loading and may serve as a prescreening model to reduce life animal testing. In the current study we examined the feasibility of organ culture of caprine lumbar discs, with the hypothesis that a simulated-physiological load will optimally preserve IVD properties. Lumbar caprine IVDs (n = 175) were cultured in a bioreactor up to 21 days either without load, low dynamic load (LDL), or with simulated-physiological load (SPL). IVD stiffness was calculated from measurements of IVD loading and displacement. IVD nucleus, inner- and outer annulus were assessed for cell viability, cell density and gene expression. The extracellular matrix (ECM) was analyzed for water, glycosaminoglycan and total collagen content. IVD biomechanical properties did not change significantly with loading conditions. With SPL, cell viability, cell density and gene expression were preserved up to 21 days. Both unloaded and LDL resulted in decreased cell viability, cell density and significant changes in gene expression, yet no differences in ECM content were observed in any group. In conclusion, simulated-physiological loading preserved the native properties of caprine IVDs during a 21-day culture period. The characterization of caprine IVD response to culture in the LDCS under SPL conditions paves the way for controlled analysis of degeneration- and regeneration-associated processes in the future.
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Affiliation(s)
- Cornelis P. L. Paul
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Research institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
| | - Hendrik A. Zuiderbaan
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
| | - Behrouz Zandieh Doulabi
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Faculty of Oral Cell Biology, Academic Centre of Dentistry Amsterdam, Amsterdam, The Netherlands
| | - Albert J. van der Veen
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Peter M. van de Ven
- Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | - Theo H. Smit
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Research institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
- Skeletal Tissue Engineering Group Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Marco N. Helder
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Research institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
- Skeletal Tissue Engineering Group Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Barend J. van Royen
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Research institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
- Skeletal Tissue Engineering Group Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Margriet G. Mullender
- Department of Orthopedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
- Research institute MOVE, VU University Medical Center, Amsterdam, The Netherlands
- Skeletal Tissue Engineering Group Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
- Department of Plastic, Reconstructive and Hand Surgery, VU University Medical Center, Amsterdam, The Netherlands
- * E-mail:
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Hwang D, Gabai AS, Yu M, Yew AG, Hsieh AH. Role of load history in intervertebral disc mechanics and intradiscal pressure generation. Biomech Model Mechanobiol 2011; 11:95-106. [PMID: 21380846 DOI: 10.1007/s10237-011-0295-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 02/03/2011] [Indexed: 11/25/2022]
Abstract
Solid-fluid interactions play an important role in mediating viscoelastic behaviour of biological tissues. In the intervertebral disc, water content is governed by a number of factors, including age, disease and mechanical loads, leading to changes in stiffness characteristics. We hypothesized that zonal stress distributions depend on load history, or the prior stresses experienced by the disc. To investigate these effects, rat caudal motion segments were subjected to compressive creep biomechanical testing in vitro using a protocol that consisted of two phases: a Prestress Phase (varied to represent different histories of load) followed immediately by an Exertion Phase, identical across all Prestress groups. Three analytical models were used to fit the experimental data in order to evaluate load history effects on gross and zonal disc mechanics. Model results indicated that while gross transient response was insensitive to load history, there may be changes in the internal mechanics of the disc. In particular, a fluid transport model suggested that the role of the nucleus pulposus in resisting creep during Exertion depended on Prestress conditions. Separate experiments using similarly defined load history regimens were performed to verify these predictions by measuring intradiscal pressure with a fibre optic sensor. We found that the ability for intradiscal pressure generation was load history-dependent and exhibited even greater sensitivity than predicted by analytical models. A 0.5 MPa Exertion load resulted in 537.2 kPa IDP for low magnitude Prestress compared with 373.7 kPa for high magnitude Prestress. Based on these measurements, we developed a simple model that may describe the pressure-shear environment in the nucleus pulposus. These findings may have important implications on our understanding of how mechanical stress contributes to disc health and disease etiology.
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Affiliation(s)
- David Hwang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
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Richardson SM, Hoyland JA, Mobasheri R, Csaki C, Shakibaei M, Mobasheri A. Mesenchymal stem cells in regenerative medicine: Opportunities and challenges for articular cartilage and intervertebral disc tissue engineering. J Cell Physiol 2010; 222:23-32. [DOI: 10.1002/jcp.21915] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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