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Barrett DW, David AL, Thrasivoulou C, Mata A, Becker DL, Engels AC, Deprest JA, Chowdhury TT. Connexin 43 is overexpressed in human fetal membrane defects after fetoscopic surgery. Prenat Diagn 2016; 36:942-952. [PMID: 27568096 PMCID: PMC5082503 DOI: 10.1002/pd.4917] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/03/2016] [Accepted: 08/20/2016] [Indexed: 12/31/2022]
Abstract
OBJECTIVE We examined whether surgically induced membrane defects elevate connexin 43 (Cx43) expression in the wound edge of the amniotic membrane (AM) and drives structural changes in collagen that affects healing after fetoscopic surgery. METHOD Cell morphology and collagen microstructure was investigated by scanning electron microscopy and second harmonic generation in fetal membranes taken from women who underwent fetal surgery. Immunofluoresence and real-time quantitative polymerase chain reaction was used to examine Cx43 expression in control and wound edge AM. RESULTS Scanning electron microscopy showed dense, helical patterns of collagen fibrils in the wound edge of the fetal membrane. This arrangement changed in the fibroblast layer with evidence of collagen fibrils that were highly polarised along the wound edge but not in control membranes. Cx43 was increased by 112.9% in wound edge AM compared with controls (p < 0.001), with preferential distribution in the fibroblast layer compared with the epithelial layer (p < 0.01). In wound edge AM, mesenchymal cells had a flattened morphology, and there was evidence of poor epithelial migration across the defect. Cx43 and COX-2 expression was significantly increased in wound edge AM compared with controls (p < 0.001). CONCLUSION Overexpression of Cx43 in the AM after fetal surgery induces morphological and structural changes in the collagenous matrix that may interfere with normal healing mechanisms. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.
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Affiliation(s)
- David W Barrett
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Anna L David
- Institute for Women's Health, University College London, London, UK
| | | | - Alvaro Mata
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - David L Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Alex C Engels
- Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium
| | - Jan A Deprest
- Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium
| | - Tina T Chowdhury
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London, UK.
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Tilwani RK, Vessillier S, Pingguan-Murphy B, Lee DA, Bader DL, Chowdhury TT. Oxygen tension modulates the effects of TNFα in compressed chondrocytes. Inflamm Res 2016; 66:49-58. [PMID: 27658702 PMCID: PMC5209429 DOI: 10.1007/s00011-016-0991-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/07/2016] [Accepted: 09/13/2016] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE AND DESIGN Oxygen tension and biomechanical signals are factors that regulate inflammatory mechanisms in chondrocytes. We examined whether low oxygen tension influenced the cells response to TNFα and dynamic compression. MATERIALS AND METHODS Chondrocyte/agarose constructs were treated with varying concentrations of TNFα (0.1-100 ng/ml) and cultured at 5 and 21 % oxygen tension for 48 h. In separate experiments, constructs were subjected to dynamic compression (15 %) and treated with TNFα (10 ng/ml) and/or L-NIO (1 mM) at 5 and 21 % oxygen tension using an ex vivo bioreactor for 48 h. Markers for catabolic activity (NO, PGE2) and tissue remodelling (GAG, MMPs) were quantified by biochemical assay. ADAMTS-5 and MMP-13 expression were examined by real-time qPCR. 2-way ANOVA and a post hoc Bonferroni-corrected t test were used to analyse data. RESULTS TNFα dose-dependently increased NO, PGE2 and MMP activity (all p < 0.001) and induced MMP-13 (p < 0.05) and ADAMTS-5 gene expression (pp < 0.01) with values greater at 5 % oxygen tension than 21 %. The induction of catabolic mediators by TNFα was reduced by dynamic compression and/or L-NIO (all p < 0.001), with a greater inhibition observed at 5% than 21 %. The stimulation of GAG synthesis by dynamic compression was greater at 21 % than 5 % oxygen tension and this response was reduced with TNFα or reversed with L-NIO. CONCLUSIONS The present findings revealed that TNFα increased production of NO, PGE2 and MMP activity at 5 % oxygen tension. The effects induced by TNFα were reduced by dynamic compression and/or the NOS inhibitor, linking both types of stimuli to reparative activities. Future therapeutics should develop oxygen-sensitive antagonists which are directed to interfering with the TNFα-induced pathways.
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Affiliation(s)
- R K Tilwani
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - S Vessillier
- Biotherapeutics Group, National Institute for Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - B Pingguan-Murphy
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - D A Lee
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - D L Bader
- Faculty of Health Sciences, Southampton General Hospital, University of Southampton, Southampton, SO16 6YD, UK
| | - T T Chowdhury
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
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Peake NJ, Bader DL, Vessillier S, Ramachandran M, Salter DM, Hobbs AJ, Chowdhury TT. C-type natriuretic peptide signalling drives homeostatic effects in human chondrocytes. Biochem Biophys Res Commun 2015; 465:784-9. [PMID: 26307537 DOI: 10.1016/j.bbrc.2015.08.087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 10/23/2022]
Abstract
Signals induced by mechanical loading and C-type natriuretic peptide (CNP) represent chondroprotective routes that may potentially prevent osteoarthritis (OA). We examined whether CNP will reduce hyaluronan production and export via members of the multidrug resistance protein (MRP) and diminish pro-inflammatory effects in human chondrocytes. The presence of interleukin-1β (IL-1β) increased HA production and export via MRP5 that was reduced with CNP and/or loading. Treatment with IL-1β conditioned medium increased production of catabolic mediators and the response was reduced with the hyaluronan inhibitor, Pep-1. The induction of pro-inflammatory cytokines by the conditioned medium was reduced by CNP and/or Pep-1, αCD44 or αTLR4 in a cytokine-dependent manner, suggesting that the CNP pathway is protective and should be exploited further.
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Affiliation(s)
- N J Peake
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - D L Bader
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - S Vessillier
- National Institute for Biological Standards and Control, Biotherapeutics Group, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK
| | - M Ramachandran
- Department of Orthopaedics and Trauma, The Royal London Hospital and Barts & The London School of Medicine & Dentistry, Queen Mary University of London, Whitechapel Road, London E1 1BB, UK
| | - D M Salter
- Centre for Genomics and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Crew Road, Edinburgh EH4 2XU, UK
| | - A J Hobbs
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, QMUL, Charterhouse Square, London EC1M 6BQ, UK
| | - T T Chowdhury
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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Encapsulation of Chondrocytes in High-Stiffness Agarose Microenvironments for In Vitro Modeling of Osteoarthritis Mechanotransduction. Ann Biomed Eng 2014; 43:1132-44. [DOI: 10.1007/s10439-014-1183-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 11/04/2014] [Indexed: 01/05/2023]
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Chowdhury B, David AL, Thrasivoulou C, Becker DL, Bader DL, Chowdhury TT. Tensile strain increased COX-2 expression and PGE2 release leading to weakening of the human amniotic membrane. Placenta 2014; 35:1057-64. [PMID: 25280972 DOI: 10.1016/j.placenta.2014.09.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/14/2014] [Accepted: 09/11/2014] [Indexed: 11/25/2022]
Abstract
INTRODUCTION There is evidence that premature rupture of the fetal membrane at term/preterm is a result of stretch and tissue weakening due to enhanced prostaglandin E2 (PGE2) production. However, the effect of tensile strain on inflammatory mediators and the stretch sensitive protein connexin-43 (Cx43) has not been examined. We determined whether the inflammatory environment influenced tissue composition and response of the tissue to tensile strain. METHODS Human amniotic membranes isolated from the cervix (CAM) or placenta regions (PAM) were examined by second harmonic generation to identify collagen orientation and subjected to tensile testing to failure. In separate experiments, specimens were subjected to cyclic tensile strain (2%, 1 Hz) for 24 h. Specimens were examined for Cx43 by immunofluorescence confocal microscopy and expression of COX-2 and Cx43 by RT-qPCR. PGE2, collagen, elastin and glycosaminoglycan (GAG) levels were analysed by biochemical assay. RESULTS Values for tensile strength were significantly higher in PAM than CAM with mechanical parameters dependent on collagen orientation. Gene expression for Cx43 and COX-2 was enhanced by tensile strain leading to increased PGE2 release and GAG levels in PAM and CAM when compared to unstrained controls. In contrast, collagen and elastin content was reduced by tensile strain in PAM and CAM. DISCUSSION Fibre orientation has a significant effect on amniotic strength. Tensile strain increased Cx43/COX-2 expression and PGE2 release resulting in tissue softening mediated by enhanced GAG levels and a reduction in collagen/elastin content. CONCLUSION A combination of inflammatory and mechanical factors may disrupt amniotic membrane biomechanics and matrix composition.
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Affiliation(s)
- B Chowdhury
- Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - A L David
- Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - C Thrasivoulou
- Department of Cell and Developmental Biology, UCL, Gower Street, London WC1E 6BT, UK
| | - D L Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University, 11, Mandalay Road, Singapore
| | - D L Bader
- Institute of Bioengineering, School of Engineering and Material Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK; Faculty of Health Sciences, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - T T Chowdhury
- Institute of Bioengineering, School of Engineering and Material Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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Thompson C, Chapple J, Knight M. Primary cilia disassembly down-regulates mechanosensitive hedgehog signalling: a feedback mechanism controlling ADAMTS-5 expression in chondrocytes. Osteoarthritis Cartilage 2014; 22:490-8. [PMID: 24457103 PMCID: PMC3988976 DOI: 10.1016/j.joca.2013.12.016] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/12/2013] [Accepted: 12/20/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Hedgehog signalling is mediated by the primary cilium and promotes cartilage degeneration in osteoarthritis. Primary cilia are influenced by pathological stimuli and cilia length and prevalence are increased in osteoarthritic cartilage. This study aims to investigate the relationship between mechanical loading, hedgehog signalling and cilia disassembly in articular chondrocytes. METHODS Primary bovine articular chondrocytes were subjected to cyclic tensile strain (CTS; 0.33 Hz, 10% or 20% strain). Hedgehog pathway activation (Ptch1, Gli1) and A Disintegrin And Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS-5) expression were assessed by real-time PCR. A chondrocyte cell line generated from the Tg737(ORPK) mouse was used to investigate the role of the cilium in this response. Cilia length and prevalence were quantified by immunocytochemistry and confocal microscopy. RESULTS Mechanical strain upregulates Indian hedgehog expression and activates hedgehog signalling. Ptch1, Gli1 and ADAMTS-5 expression were increased following 10% CTS, but not 20% CTS. Pathway activation requires a functioning primary cilium and is not observed in Tg737(ORPK) cells lacking cilia. Mechanical loading significantly reduced cilium length such that cilia became progressively shorter with increasing strain magnitude. Inhibition of histone deacetylase 6 (HDAC6), a tubulin deacetylase, prevented cilia disassembly and restored mechanosensitive hedgehog signalling and ADAMTS-5 expression at 20% CTS. CONCLUSIONS This study demonstrates for the first time that mechanical loading activates primary cilia-mediated hedgehog signalling and ADAMTS-5 expression in adult articular chondrocytes, but that this response is lost at high strains due to HDAC6-mediated cilia disassembly. The study provides new mechanistic insight into the role of primary cilia and mechanical loading in articular cartilage.
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Affiliation(s)
- C.L. Thompson
- Institute of Bioengineering, School of Engineering and Material Sciences, Queen Mary University of London, London, UK,Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK,Address correspondence and reprint requests to: C.L. Thompson, Institute of Bioengineering, School of Engineering and Material Sciences, Queen Mary University of London, London E1 4NS, UK. Tel: 44-(0)-20-7882-9307.
| | - J.P. Chapple
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - M.M. Knight
- Institute of Bioengineering, School of Engineering and Material Sciences, Queen Mary University of London, London, UK
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Parker E, Vessillier S, Pingguan-Murphy B, Abas W, Bader DL, Chowdhury TT. Low oxygen tension increased fibronectin fragment induced catabolic activities--response prevented with biomechanical signals. Arthritis Res Ther 2013; 15:R163. [PMID: 24286132 PMCID: PMC3978917 DOI: 10.1186/ar4346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 09/27/2013] [Indexed: 11/10/2022] Open
Abstract
Introduction The inherent low oxygen tension in normal cartilage has implications on inflammatory conditions associated with osteoarthritis (OA). Biomechanical signals will additionally contribute to changes in tissue remodelling and influence the inflammatory response. In this study, we investigated the combined effects of oxygen tension and fibronectin fragment (FN-f) on the inflammatory response of chondrocytes subjected to biomechanical signals. Methods Chondrocytes were cultured under free-swelling conditions at 1%, 5% and 21% oxygen tension or subjected to dynamic compression in an ex vivo 3D/bioreactor model with 29 kDa FN-f, interleukin-1beta (IL-1β) and/or the nitric oxide synthase (NOS) inhibitor for 6 and 48 hours. Markers for catabolic activity (NO, PGE2), tissue remodelling (GAG, MMPs) and cytokines (IL-1β, IL-6 and TNFα) were quantified by biochemical assay. Aggrecan, collagen type II, iNOS and COX-2 gene expression were examined by real-time quantitative PCR. Two-way ANOVA and a post hoc Bonferroni-corrected t-test were used to analyse data. Results Both FN-fs and IL-1β increased NO, PGE2 and MMP production (all P < 0.001). FN-f was more active than IL-1β with greater levels of NO observed at 5% than 1% or 21% oxygen tension (P < 0.001). Whilst FN-f reduced GAG synthesis at all oxygen tension, the effect of IL-1β was significant at 1% oxygen tension. In unstrained constructs, treatment with FN-f or IL-1β increased iNOS and COX-2 expression and reduced aggrecan and collagen type II (all P < 0.001). In unstrained constructs, FN-f was more effective than IL-1β at 5% oxygen tension and increased production of NO, PGE2, MMP, IL-1β, IL-6 and TNFα. At 5% and 21% oxygen tension, co-stimulation with compression and the NOS inhibitor abolished fragment or cytokine-induced catabolic activities and restored anabolic response. Conclusions The present findings revealed that FN-fs are more potent than IL-1β in exerting catabolic effects dependent on oxygen tension via iNOS and COX-2 upregulation. Stimulation with biomechanical signals abolished catabolic activities in an oxygen-independent manner and NOS inhibitors supported loading-induced recovery resulting in reparative activities. Future investigations will utilize the ex vivo model as a tool to identify key targets and therapeutics for OA treatments.
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Peake N, Su N, Ramachandran M, Achan P, Salter DM, Bader DL, Moyes AJ, Hobbs AJ, Chowdhury TT. Natriuretic peptide receptors regulate cytoprotective effects in a human ex vivo 3D/bioreactor model. Arthritis Res Ther 2013; 15:R76. [PMID: 23883591 PMCID: PMC3978875 DOI: 10.1186/ar4253] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 07/24/2013] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION The present study examined the effect of C-type natriuretic peptide (CNP) and biomechanical signals on anabolic and catabolic activities in chondrocyte/agarose constructs. METHODS Natriuretic peptide (Npr) 2 and 3 expression were compared in non-diseased (grade 0/1) and diseased (grade IV) human cartilage by immunofluoresence microscopy and western blotting. In separate experiments, constructs were cultured under free-swelling conditions or subjected to dynamic compression with CNP, interleukin-1β (IL-1β), the Npr2 antagonist P19 or the Npr3 agonist cANF⁴⁻²³. Nitric oxide (NO) production, prostaglandin E₂ (PGE₂) release, glycosaminoglycan (GAG) synthesis and CNP concentration were quantified using biochemical assays. Gene expression of Npr2, Npr3, CNP, aggrecan and collagen type II were assessed by real-time qPCR. Two-way ANOVA and a post hoc Bonferroni-corrected t-test were used to analyse the data. RESULTS The present study demonstrates increased expression of natriuretic peptide receptors in diseased or older cartilage (age 70) when compared to non-diseased tissue (age 60) which showed minimal expression. There was strong parallelism in the actions of CNP on cGMP induction resulting in enhanced GAG synthesis and reduction of NO and PGE₂ release induced by IL-1β. Inhibition of Npr2 with P19 maintained catabolic activities whilst specific agonism of Npr3 with cANF⁴⁻²³ had the opposite effect and reduced NO and PGE₂ release. Co-stimulation with CNP and dynamic compression enhanced anabolic activities and inhibited catabolic effects induced by IL-1β. The presence of CNP and the Npr2 antagonist abolished the anabolic response to mechanical loading and prevented loading-induced inhibition of NO and PGE₂ release. In contrast, the presence of the Npr3 agonist had the opposite effect and increased GAG synthesis and cGMP levels in response to mechanical loading and reduced NO and PGE₂ release comparable to control samples. In addition, CNP concentration and natriuretic peptide receptor expression were increased with dynamic compression. CONCLUSIONS Mechanical loading mediates endogenous CNP release leading to increased natriuretic peptide signalling. The loading-induced CNP/Npr2/cGMP signalling route mediates anabolic events and prevents catabolic activities induced by IL-1β. The CNP pathway therefore represents a potentially chondroprotective intervention for patients with OA, particularly when combined with physiotherapeutic approaches to stimulate biomechanical signals.
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Tilwani RK, Bader DL, Chowdhury TT. Biomechanical Conditioning Enhanced Matrix Synthesis in Nucleus Pulposus Cells Cultured in Agarose Constructs with TGFβ. J Funct Biomater 2012; 3:23-36. [PMID: 24956513 PMCID: PMC4031018 DOI: 10.3390/jfb3010023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 12/23/2011] [Accepted: 12/28/2011] [Indexed: 11/24/2022] Open
Abstract
Biomechanical signals play an important role in normal disc metabolism and pathology. For instance, nucleus pulposus (NP) cells will regulate metabolic activities and maintain a balance between the anabolic and catabolic cascades. The former involves factors such as transforming growth factor-β (TGFβ) and mechanical stimuli, both of which are known to regulate matrix production through autocrine and paracrine mechanisms. The present study examined the combined effect of TGFβ and mechanical loading on anabolic activities in NP cells cultured in agarose constructs. Stimulation with TGFβ and dynamic compression reduced nitrite release and increased matrix synthesis and gene expression of aggrecan and collagen type II. The findings from this work has the potential for developing regenerative treatment strategies which could either slow down or stop the degenerative process and/or promote healing mechanisms in the intervertebral disc.
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Affiliation(s)
- Reshma K Tilwani
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Dan L Bader
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Tina T Chowdhury
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1β in chondrocyte/agarose constructs. Arthritis Res Ther 2011; 13:R145. [PMID: 21914170 PMCID: PMC3308073 DOI: 10.1186/ar3459] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 08/02/2011] [Accepted: 09/13/2011] [Indexed: 11/10/2022] Open
Abstract
Introduction The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression. Methods Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1β (IL-1β), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data. Results CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1β. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1β (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1β, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1β-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1β-treated constructs. Conclusions Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1β. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old.
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Chowdhury TT, Schulz RM, Rai SS, Thuemmler CB, Wuestneck N, Bader A, Homandberg GA. Biomechanical modulation of collagen fragment-induced anabolic and catabolic activities in chondrocyte/agarose constructs. Arthritis Res Ther 2010; 12:R82. [PMID: 20462435 PMCID: PMC2911866 DOI: 10.1186/ar3009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 01/26/2010] [Accepted: 05/12/2010] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION The present study examined the effect of collagen fragments on anabolic and catabolic activities by chondrocyte/agarose constructs subjected to dynamic compression. METHODS Constructs were cultured under free-swelling conditions or subjected to continuous and intermittent compression regimes, in the presence of the N-terminal (NT) and C-terminal (CT) telopeptides derived from collagen type II and/or 1400 W (inhibits inducible nitric oxide synthase (iNOS)). The anabolic and catabolic activities were compared to the amino-terminal fibronectin fragment (NH2-FN-f) and assessed as follows: nitric oxide (NO) release and sulphated glycosaminoglycan (sGAG) content were quantified using biochemical assays. Tumour necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) release were measured by ELISA. Gene expression of matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-13 (MMP-13), collagen type II and fibronectin were assessed by real-time quantitative polymerase chain reaction (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t-test was used to examine data. RESULTS The presence of the NT or CT peptides caused a moderate to strong dose-dependent stimulation of NO, TNFalpha and IL-1beta production and inhibition of sGAG content. In some instances, high concentrations of telopeptides were just as potent in stimulating catabolic activities when compared to NH2-FN-f. Depending on the concentration and type of fragment, the increased levels of NO and cytokines were inhibited with 1400 W, resulting in the restoration of sGAG content. Depending on the duration and type of compression regime employed, stimulation with compression or incubation with 1400 W or a combination of both, inhibited telopeptide or NH2-FN-f induced NO release and cytokine production and enhanced sGAG content. All fragments induced MMP-3 and MMP-13 expression in a time-dependent manner. This effect was reversed with compression and/or 1400 W resulting in the restoration of sGAG content and induction of collagen type II and fibronectin expression. CONCLUSIONS Collagen fragments containing the N- and C-terminal telopeptides have dose-dependent catabolic activities similar to fibronectin fragments and increase the production of NO, cytokines and MMPs. Catabolic activities were downregulated by dynamic compression or by the presence of the iNOS inhibitor, linking reparative activities by both types of stimuli. Future investigations which examine the signalling cascades of chondrocytes in response to matrix fragments with mechanical influences may provide useful information for early osteoarthritis treatments.
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Affiliation(s)
- Tina T Chowdhury
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Ronny M Schulz
- Department of Cell Techniques and Applied Stem Cell Biology, University of Leipzig, Deutscher Platz 5, Leipzig, 04103, Germany
| | - Sonpreet S Rai
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Christian B Thuemmler
- Department of Cell Techniques and Applied Stem Cell Biology, University of Leipzig, Deutscher Platz 5, Leipzig, 04103, Germany
| | - Nico Wuestneck
- Department of Cell Techniques and Applied Stem Cell Biology, University of Leipzig, Deutscher Platz 5, Leipzig, 04103, Germany
| | - Augustinus Bader
- Department of Cell Techniques and Applied Stem Cell Biology, University of Leipzig, Deutscher Platz 5, Leipzig, 04103, Germany
| | - Gene A Homandberg
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Box 9037, Grand Forks, ND 58202, USA
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