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Jia Y, Le H, Wang X, Zhang J, Liu Y, Ding J, Zheng C, Chang F. Double-edged role of mechanical stimuli and underlying mechanisms in cartilage tissue engineering. Front Bioeng Biotechnol 2023; 11:1271762. [PMID: 38053849 PMCID: PMC10694366 DOI: 10.3389/fbioe.2023.1271762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/11/2023] [Indexed: 12/07/2023] Open
Abstract
Mechanical stimuli regulate the chondrogenic differentiation of mesenchymal stem cells and the homeostasis of chondrocytes, thus affecting implant success in cartilage tissue engineering. The mechanical microenvironment plays fundamental roles in the maturation and maintenance of natural articular cartilage, and the progression of osteoarthritis Hence, cartilage tissue engineering attempts to mimic this environment in vivo to obtain implants that enable a superior regeneration process. However, the specific type of mechanical loading, its optimal regime, and the underlying molecular mechanisms are still under investigation. First, this review delineates the composition and structure of articular cartilage, indicating that the morphology of chondrocytes and components of the extracellular matrix differ from each other to resist forces in three top-to-bottom overlapping zones. Moreover, results from research experiments and clinical trials focusing on the effect of compression, fluid shear stress, hydrostatic pressure, and osmotic pressure are presented and critically evaluated. As a key direction, the latest advances in mechanisms involved in the transduction of external mechanical signals into biological signals are discussed. These mechanical signals are sensed by receptors in the cell membrane, such as primary cilia, integrins, and ion channels, which next activate downstream pathways. Finally, biomaterials with various modifications to mimic the mechanical properties of natural cartilage and the self-designed bioreactors for experiment in vitro are outlined. An improved understanding of biomechanically driven cartilage tissue engineering and the underlying mechanisms is expected to lead to efficient articular cartilage repair for cartilage degeneration and disease.
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Affiliation(s)
- Yao Jia
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
- The Second Bethune Clinical Medical College of Jilin University, Jilin, China
| | - Hanxiang Le
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
- The Fourth Treatment Area of Trauma Hip Joint Surgery Department, Tianjin Hospital, Tianjin, China
| | - Xianggang Wang
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
| | - Jiaxin Zhang
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
| | - Yan Liu
- The Second Bethune Clinical Medical College of Jilin University, Jilin, China
| | - Jiacheng Ding
- The Second Bethune Clinical Medical College of Jilin University, Jilin, China
| | - Changjun Zheng
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
| | - Fei Chang
- Department of Orthopedics, The Second Hospital of Jilin University, Jilin, China
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Abusharkh HA, Reynolds OM, Mendenhall J, Gozen BA, Tingstad E, Idone V, Abu-Lail NI, Van Wie BJ. Combining stretching and gallic acid to decrease inflammation indices and promote extracellular matrix production in osteoarthritic human articular chondrocytes. Exp Cell Res 2021; 408:112841. [PMID: 34563516 DOI: 10.1016/j.yexcr.2021.112841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 08/21/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
Osteoarthritis (OA) patients undergo cartilage degradation and experience painful joint swelling. OA symptoms are caused by inflammatory molecules and the upregulation of catabolic genes leading to the breakdown of cartilage extracellular matrix (ECM). Here, we investigate the effects of gallic acid (GA) and mechanical stretching on the expression of anabolic and catabolic genes and restoring ECM production by osteoarthritic human articular chondrocytes (hAChs) cultured in monolayers. hAChs were seeded onto conventional plates or silicone chambers with or without 100 μM GA. A 5% cyclic tensile strain (CTS) was applied to the silicone chambers and the deposition of collagen and glycosaminoglycan, and gene expressions of collagen types II (COL2A1), XI (COL11A2), I (COL1A1), and X (COL10A1), and matrix metalloproteinases (MMP-1 and MMP-13) as inflammation markers, were quantified. CTS and GA acted synergistically to promote the deposition of collagen and glycosaminoglycan in the ECM by 14- and 7-fold, respectively. Furthermore, the synergistic stimuli selectively upregulated the expression of cartilage-specific proteins, COL11A2 by 7-fold, and COL2A1 by 47-fold, and, in contrast, downregulated the expression of MMP-1 by 2.5-fold and MMP-13 by 125-fold. GA supplementation with CTS is a promising approach for restoring osteoarthritic hAChs ECM production ability making them suitable for complex tissue engineering applications.
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Affiliation(s)
- Haneen A Abusharkh
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, 99164-6515, USA.
| | - Olivia M Reynolds
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, 99164-6515, USA.
| | - Juana Mendenhall
- Department of Chemistry, Morehouse College, Atlanta, GA, 30314, USA.
| | - Bulent A Gozen
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164-2920, USA.
| | - Edwin Tingstad
- Inland Orthopedic Surgery and Sports Medicine Clinic, Pullman, WA, 99163, USA.
| | - Vincent Idone
- Regeneron Pharmaceuticals Inc, Tarrytown, NY, 10591, USA.
| | - Nehal I Abu-Lail
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, TX, 78249-3209, USA.
| | - Bernard J Van Wie
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, 99164-6515, USA.
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3
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Jin H, Jiang S, Wang R, Zhang Y, Dong J, Li Y. Mechanistic Insight Into the Roles of Integrins in Osteoarthritis. Front Cell Dev Biol 2021; 9:693484. [PMID: 34222261 PMCID: PMC8250141 DOI: 10.3389/fcell.2021.693484] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 05/19/2021] [Indexed: 01/13/2023] Open
Abstract
Osteoarthritis (OA), one of the most common degenerative diseases, is characterized by progressive degeneration of the articular cartilage and subchondral bone, as well as the synovium. Integrins, comprising a family of heterodimeric transmembrane proteins containing α subunit and β subunit, play essential roles in various physiological functions of cells, such as cell attachment, movement, growth, differentiation, and mechanical signal conduction. Previous studies have shown that integrin dysfunction is involved in OA pathogenesis. This review article focuses on the roles of integrins in OA, especially in OA cartilage, subchondral bone and the synovium. A clear understanding of these roles may influence the future development of treatments for OA.
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Affiliation(s)
- Hongfu Jin
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Shigang Jiang
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ruomei Wang
- Department of Endocrinology and Metabolic Diseases, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yi Zhang
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Jiangtao Dong
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yusheng Li
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
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4
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Lee JK, Huwe LW, Paschos N, Aryaei A, Gegg CA, Hu JC, Athanasiou KA. Tension stimulation drives tissue formation in scaffold-free systems. NATURE MATERIALS 2017; 16:864-873. [PMID: 28604717 PMCID: PMC5532069 DOI: 10.1038/nmat4917] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 05/04/2017] [Indexed: 05/04/2023]
Abstract
Scaffold-free systems have emerged as viable approaches for engineering load-bearing tissues. However, the tensile properties of engineered tissues have remained far below the values for native tissue. Here, by using self-assembled articular cartilage as a model to examine the effects of intermittent and continuous tension stimulation on tissue formation, we show that the application of tension alone, or in combination with matrix remodelling and synthesis agents, leads to neocartilage with tensile properties approaching those of native tissue. Implantation of tension-stimulated tissues results in neotissues that are morphologically reminiscent of native cartilage. We also show that tension stimulation can be translated to a human cell source to generate anisotropic human neocartilage with enhanced tensile properties. Tension stimulation, which results in nearly sixfold improvements in tensile properties over unstimulated controls, may allow the engineering of mechanically robust biological replacements of native tissue.
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Affiliation(s)
- Jennifer K. Lee
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Le W. Huwe
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Nikolaos Paschos
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Ashkan Aryaei
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Courtney A. Gegg
- Department of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305
| | - Jerry C. Hu
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Kyriacos A. Athanasiou
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
- Department of Orthopaedic Surgery, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
- Correspondence and reprint requests should be addressed to: KA Athanasiou, Tel.: (530) 754-6645, Fax: (530) 754-5739, , Department of Biomedical Engineering, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
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Yu HS, Kim JJ, Kim HW, Lewis MP, Wall I. Impact of mechanical stretch on the cell behaviors of bone and surrounding tissues. J Tissue Eng 2016; 7:2041731415618342. [PMID: 26977284 PMCID: PMC4765821 DOI: 10.1177/2041731415618342] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 10/15/2015] [Indexed: 12/27/2022] Open
Abstract
Mechanical loading is recognized to play an important role in regulating the behaviors of cells in bone and surrounding tissues in vivo. Many in vitro studies have been conducted to determine the effects of mechanical loading on individual cell types of the tissues. In this review, we focus specifically on the use of the Flexercell system as a tool for studying cellular responses to mechanical stretch. We assess the literature describing the impact of mechanical stretch on different cell types from bone, muscle, tendon, ligament, and cartilage, describing individual cell phenotype responses. In addition, we review evidence regarding the mechanotransduction pathways that are activated to potentiate these phenotype responses in different cell populations.
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Affiliation(s)
- Hye-Sun Yu
- Department of Biochemical Engineering, University College London, London, UK; Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, Dankook University Graduate School, Cheonan, South Korea; Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, South Korea
| | - Jung-Ju Kim
- Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, Dankook University Graduate School, Cheonan, South Korea; Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, South Korea
| | - Hae-Won Kim
- Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, Dankook University Graduate School, Cheonan, South Korea; Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, South Korea; Department of Biomaterials Science, School of Dentistry, Dankook University, Cheonan, South Korea
| | - Mark P Lewis
- Musculo-Skeletal Biology Research Group, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Ivan Wall
- Department of Biochemical Engineering, University College London, London, UK; Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, Dankook University Graduate School, Cheonan, South Korea
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6
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Bleuel J, Zaucke F, Brüggemann GP, Niehoff A. Effects of cyclic tensile strain on chondrocyte metabolism: a systematic review. PLoS One 2015; 10:e0119816. [PMID: 25822615 PMCID: PMC4379081 DOI: 10.1371/journal.pone.0119816] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/16/2015] [Indexed: 12/25/2022] Open
Abstract
Chondrocytes reorganize the extracellular matrix of articular cartilage in response to externally applied loads. Thereby, different loading characteristics lead to different biological responses. Despite of active research in this area, it is still unclear which parts of the extracellular matrix adapt in what ways, and how specific loading characteristics affect matrix changes. This review focuses on the influence of cyclic tensile strain on chondrocyte metabolism in vitro. It also aimed to identify anabolic or catabolic chondrocyte responses to different loading protocols. The key findings show that loading cells up to 3% strain, 0.17 Hz, and 2 h, resulted in weak or no biological responses. Loading between 3–10% strain, 0.17–0.5 Hz, and 2–12 h led to anabolic responses; and above 10% strain, 0.5 Hz, and 12 h catabolic events predominated. However, this review also discusses that various other factors are involved in the remodeling of the extracellular matrix in response to loading, and that parameters like an inflammatory environment might influence the biological response.
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Affiliation(s)
- Judith Bleuel
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Köln, Germany
- * E-mail:
| | - Frank Zaucke
- Center for Biochemistry, Medical Faculty, University of Cologne, Köln, Germany
- Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Köln, Germany
| | - Gert-Peter Brüggemann
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Köln, Germany
- Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Köln, Germany
| | - Anja Niehoff
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Köln, Germany
- Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Köln, Germany
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8
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Tian J, Zhang FJ, Lei GH. Role of integrins and their ligands in osteoarthritic cartilage. Rheumatol Int 2014; 35:787-98. [PMID: 25261047 DOI: 10.1007/s00296-014-3137-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 09/17/2014] [Indexed: 12/31/2022]
Abstract
Osteoarthritis (OA) is a degenerative disease, which is characterized by articular cartilage destruction, and mainly affects the older people. The extracellular matrix (ECM) provides a vital cellular environment, and interactions between the cell and ECM are important in regulating many biological processes, including cell growth, differentiation, and survival. However, the pathogenesis of this disease is not fully elucidated, and it cannot be cured totally. Integrins are one of the major receptors in chondrocytes. A number of studies confirmed that the chondrocytes express several integrins including α5β1, αVβ3, αVβ5, α6β1, α1β1, α2β1, α10β1, and α3β1, and some integrins ligands might act as the OA progression biomarkers. This review focuses on the functional role of integrins and their extracellular ligands in OA progression, especially OA cartilage. Clear understanding of the role of integrins and their ligands in OA cartilage may have impact on future development of successful therapeutic approaches to OA.
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Affiliation(s)
- Jian Tian
- Department of Orthopaedics, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan, China
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9
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Hoshiba T, Lu H, Kawazoe N, Yamada T, Chen G. Effects of extracellular matrix proteins in chondrocyte-derived matrices on chondrocyte functions. Biotechnol Prog 2013; 29:1331-6. [PMID: 23847171 DOI: 10.1002/btpr.1780] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 06/16/2013] [Indexed: 11/08/2022]
Abstract
Loss of cartilaginous phenotype during in vitro expansion culture of chondrocytes is a major barrier to the application of chondrocytes for tissue engineering. In previous study, we showed that dedifferentiation of chondrocytes during the passage culture was delayed by matrices formed by primary chondrocytes (P0-ECM). In this study, we investigated bovine chondrocyte functions when being cultured on isolated extracellular matrix (ECM) protein-coated substrata and P0-ECM. Low chondrocyte attachment was observed on aggrecan-coated substratum and P0-ECM. Cell proliferation on aggrecan- and type II collagen/aggrecan-coated substrata and P0-ECM was lower than that on the other ECM protein (type I collagen and type II collagen)-coated substrata. When chondrocytes were subcultured on aggrecan-coated substratum, decline of cartilaginous gene expression was delayed, which was similar to the cells subcultured on P0-ECM. These results indicate that aggrecan plays an important role in the regulation of chondrocyte functions and P0-ECM may be a good experimental control for investigating the role of each ECM protein in cartilage ECM.
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Affiliation(s)
- Takashi Hoshiba
- Tissue Regeneration Materials Unit, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
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Rosenzweig DH, Solar-Cafaggi S, Quinn TM. Functionalization of dynamic culture surfaces with a cartilage extracellular matrix extract enhances chondrocyte phenotype against dedifferentiation. Acta Biomater 2012; 8:3333-41. [PMID: 22659179 DOI: 10.1016/j.actbio.2012.05.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/15/2012] [Accepted: 05/23/2012] [Indexed: 12/16/2022]
Abstract
Culture on silicone rubber surfaces has been shown to partially overcome the chondrocyte dedifferentiation characteristic of standard culture on rigid polystyrene. These methods typically involve functionalization of culture surfaces with proteins. Collagen type I is often used, but more cartilage-specific proteins may be more appropriate for chondrocytes. To explore this hypothesis, a twofold experimental design was applied. First, chondrocytes were cultured in rigid Petri dishes coated with silicone rubber ("static silicone" or SS culture) functionalized with either cartilage extracellular matrix (ECM) extract or collagen type I. Second, chondrocytes were cultured on monotonically expanded high extension silicone rubber dishes ("continuous expansion" or CE culture) functionalized with ECM extract and compared to cells grown in SS culture. There were no differential effects of surface functionalization with the ECM extract vs. collagen type I on chondrocyte morphology, viability, proliferation or apoptosis in SS culture. However, chondrocyte growth on the ECM extract was associated with significantly reduced collagen types I and X gene expression and significantly increased glycosaminoglycan (GAG) secretion. After 3 passages (P3) on ECM-coated SS culture, chondrocyte phenotype and GAG secretion was enhanced compared to cells passaged on collagen type I. Pellet cultures from P3 SS culture displayed enhanced collagen type II content when ECM extract was used for functionalization rather than collagen type I. In CE culture with ECM functionalization, chondrocyte dedifferentiation was significantly inhibited vs. SS cultures, as evidenced by both gene expression and pellet cultures. Functionalization of extendable culture surfaces with cartilage ECM extract therefore supports enhanced preservation of chondrocyte phenotype.
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Abstract
Dynamic interactions between cells and extracellular matrix (ECM) through integrins influence most cellular functions. Normal cells, but even more, tumor cells are subjected to different forms of stress, including ischemia, radical oxygen species production, starvation, mechanical stress or genotoxic insults due to anti-cancer drugs or irradiation. In these situations, an adaptative cellular response occurs, integrating a complex network of intracellular signaling modules, which, depending on stress intensity, may result to either damage repair followed by complete restitution of cellular functions, or programmed cell death. Because of its implication in oncogenesis and anti-cancer therapy, cellular stress response has been thoroughly investigated. However, most of these studies have been performed in the context of isolated cells without taking into consideration that most cells are part of the tissue within which they interact with ECM through integrin. Few studies have described the influence of stress on cell-to-ECM interaction. However, one can speculate that, in these conditions, cells could functionally interact with protein microenvironment either to create positive interactions to survive (for example by facilitating protective pathways) or negative interaction to die (for example by facilitating detachment). In this review, we summarize the knowledge relative to the influence of different stress modalities on ECM remodeling, integrin expression and/or function modifications, and possible functional consequences, independently from the cellular model as these findings came from a large variety of cells (mesenchymal, endothelial, muscular, epithelial and glandular) and fields of application (cancer, vascular biology and tissue engineering). Most studies support the general notion that non-lethal stress favors ECM stiffness, integrin activation and enhanced survival. This field opens large perspectives not only in tumor biology but also in anti-cancer therapy by targeting one or several steps of the integrin-mediated signaling pathway, including integrin ligation, or activation of integrin-linked enzymes or integrin adaptors.
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Blain EJ. Involvement of the cytoskeletal elements in articular cartilage homeostasis and pathology. Int J Exp Pathol 2009; 90:1-15. [PMID: 19200246 DOI: 10.1111/j.1365-2613.2008.00625.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The cytoskeleton of all cells is a three-dimensional network comprising actin microfilaments, tubulin microtubules and intermediate filaments. Studies in many cell types have indicated roles for these cytoskeletal proteins in many diverse cellular processes including alteration of cell shape, movement of organelles, migration, endocytosis, secretion, cell division and extracellular matrix assembly. The cytoskeletal networks are highly organized in structure enabling them to fulfil their biological functions. This review will primarily focus on the organization and function of the three major cytoskeletal networks in articular cartilage chondrocytes. Articular cartilage is a major load-bearing tissue of the synovial joint; it is well known that the cytoskeleton acts as a physical interface between the chondrocytes and the extracellular matrix in 'sensing' mechanical stimuli. The effect of mechanical load on cytoskeletal element expression and organization will also be reviewed. Abnormal mechanical load is widely believed to be a risk factor for the development of osteoarthritis. Several studies have intimated that the major cytoskeletal networks are disorganized or often absent in osteoarthritic cartilage chondrocytes. The implications and possible reasoning for this are more widely discussed and placed into context with their potential relevance to disease and therapeutic strategies.
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Affiliation(s)
- Emma J Blain
- Connective Tissue Biology Laboratories, School of Biosciences, Cardiff University, Cardiff, UK.
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Nishida T, Kawaki H, Baxter RM, Deyoung RA, Takigawa M, Lyons KM. CCN2 (Connective Tissue Growth Factor) is essential for extracellular matrix production and integrin signaling in chondrocytes. J Cell Commun Signal 2007; 1:45-58. [PMID: 18481209 DOI: 10.1007/s12079-007-0005-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 04/04/2007] [Indexed: 12/31/2022] Open
Abstract
The matricellular protein CCN2 (Connective Tissue Growth Factor; CTGF) is an essential mediator of ECM composition, as revealed through analysis of Ccn2 deficient mice. These die at birth due to complications arising from impaired endochondral ossification. However, the mechanism(s) by which CCN2 mediates its effects in cartilage are unclear. We investigated these mechanisms using Ccn2 ( -/- ) chondrocytes. Expression of type II collagen and aggrecan were decreased in Ccn2 (-/-) chondrocytes, confirming a defect in ECM production. Ccn2 ( -/- ) chondrocytes also exhibited impaired DNA synthesis and reduced adhesion to fibronectin. This latter defect is associated with decreased expression of alpha5 integrin. Moreover, CCN2 can bind to integrin alpha5beta1 in chondrocytes and can stimulate increased expression of integrin alpha5. Consistent with an essential role for CCN2 as a ligand for integrins, immunofluorescence and Western blot analysis revealed that levels of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK)1/2 phosphorylation were reduced in Ccn2 ( -/- ) chondrocytes. These findings argue that CCN2 exerts major effects in chondrocytes through its ability to (1) regulate ECM production and integrin alpha5 expression, (2) engage integrins and (3) activate integrin-mediated signaling pathways.
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Affiliation(s)
- Takashi Nishida
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, 2641 MacDonald Research Laboratories, 675 Charles E. Young Dr. South, Los Angeles, CA, 90095, USA
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