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Bao JP, Chen WP, Wu LD. Lubricin: a novel potential biotherapeutic approaches for the treatment of osteoarthritis. Mol Biol Rep 2010; 38:2879-85. [PMID: 20099082 DOI: 10.1007/s11033-010-9949-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 01/14/2010] [Indexed: 10/19/2022]
Abstract
Osteoarthritis (OA) is a multi-factor disorder of sinovial joints, which characterized by escalated degeneration and loss of articular cartilage. Treatment of OA is a critical unmet need in medicine for regeneration of damaged articular cartilage in elderly. On the other hand, lubricin, a glycoprotein specifically synthesized by chondrocytes located at the surface of articular cartilage, has been shown to provide boundary lubrication of congruent articular surfaces under conditions of high contact pressure and near zero sliding speed. Lubrication of these surfaces is critical to normal joint function, while different gene expressions of lubricin had been found in the synovium of rheumatoid arthritis (RA) and OA. Moreover, mutations or lacking of lubricin gene have been shown to link to the joint disease such as camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP), synovial hyperplasia and failure of joint function, suggesting an important role of lubricin in the pathogenesis of these joint disease. Recent studies demonstrate that administration with recombinant lubricin in the joint cavity would be effective in the prevention of cartilage degeneration in animal OA models. Therefore, a treatment with lubricin which would protect cartilage in vivo would be desirable. This article reviews recent findings with regard to the possible role of lubricin in the progression of OA, and further discusses lubricin as a novel potential biotherapeutic approaches for the treatment of OA.
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Affiliation(s)
- Jia-Peng Bao
- Department of Orthopedics Surgery, The Second Hospital of Medical College, Zhejiang University, JieFang Road 88#, 310009 Hangzhou, People's Republic of China
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102
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Elsaid KA, Machan JT, Waller K, Fleming BC, Jay GD. The impact of anterior cruciate ligament injury on lubricin metabolism and the effect of inhibiting tumor necrosis factor alpha on chondroprotection in an animal model. ACTA ACUST UNITED AC 2009; 60:2997-3006. [PMID: 19790069 DOI: 10.1002/art.24800] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To examine the effects of anterior cruciate ligament transection (ACLT) in a rat model on lubricin metabolism and its relationship to markers of inflammation and cartilage damage, and to determine whether blocking the metabolic effects of tumor necrosis factor alpha (TNFalpha) by etanercept increases the chondroprotection provided by lubricin. METHODS Unilateral ACLT was performed in Lewis rats. Levels of lubricin, TNFalpha, interleukin-1beta (IL-1beta), and sulfated glycosaminoglycans (sGAG) in synovial fluid (SF) lavage specimens and synovial tissue lubricin gene expression were evaluated at 1 week and 4 weeks following ACLT. Histologic evaluation of articular cartilage included staining with lubricin-specific monoclonal antibody 9G3 and Safranin O. The percentage of lubricin staining on the surface of articular cartilage in weight-bearing areas was estimated by digital imaging. Blocking of TNFalpha was performed using etanercept, which was administered subcutaneously at a dose of 0.5 mg/kg around the ACL-transected joints, using different dosing strategies. The ACL-transected and contralateral joints of these rats were harvested 4 weeks following surgery. RESULTS Four weeks following ACLT, SF lubricin concentrations and the percentage of cartilage surface lubricin staining were significantly lower in the injured joints compared with the contralateral joints. A significant decrease in synovial tissue lubricin gene expression was associated with elevated TNFalpha and IL-1beta concentrations in SF lavage samples. With all of the etanercept treatment strategies, blocking of TNFalpha significantly increased the amount of lubricin bound to cartilage, coupled with a significant decrease in sGAG release. However, changes in the concentrations of lubricin in SF were variable. CONCLUSION Blocking TNFalpha resulted in a chondroprotective effect, exemplified by increased lubricin deposition on articular cartilage and a decrease in sGAG release from articular cartilage in an animal model of posttraumatic arthritis.
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Affiliation(s)
- K A Elsaid
- Brown University, Providence, Rhode Island, USA
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103
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Chang DP, Abu-Lail NI, Coles JM, Guilak F, Jay GD, Zauscher S. Friction Force Microscopy of Lubricin and Hyaluronic Acid between Hydrophobic and Hydrophilic Surfaces. SOFT MATTER 2009; 5:3438-3445. [PMID: 20936046 PMCID: PMC2951324 DOI: 10.1039/b907155e] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Lubricin and hyaluronic acid (HA), molecular constituents of synovial fluid, have long been theorized to play a role in joint lubrication and wear protection. While lubricin has been shown to function as a boundary lubricant, conflicting evidence exists as to the boundary lubricating ability of hyaluronic acid. Here, we use colloidal force microscopy to explore the friction behavior of these two molecules on the microscale between chemically uniform hydrophilic (hydroxyl-terminated) and hydrophobic (methyl-terminated) surfaces in physiological buffer solution. Behaviors on both surfaces are physiologically relevant since the heterogeneous articular cartilage surface contains both hydrophilic and hydrophobic elements. Friction between hydrophobic surfaces was initially high (μ=1.1, at 100nN of applied normal load) and was significantly reduced by lubricin addition while friction between hydrophilic surfaces was initially low (μ=0.1) and was slightly increased by lubricin addition. At lubricin concentrations above 200 µg/ml, friction behavior on the two surfaces was similar (μ=0.2) indicating that nearly all interaction between the two surfaces was between adsorbed lubricin molecules rather than between the surfaces themselves. In contrast, addition of HA did not appreciably alter the frictional behavior between the model surfaces. No synergistic effect on friction behavior was seen in a physiological mixture of lubricin and HA. Lubricin can equally mediate the frictional response between both hydrophilic and hydrophobic surfaces, likely fully preventing direct surface-to-surface contact at sufficient concentrations, whereas HA provides considerably less boundary lubrication.
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Affiliation(s)
- Debby P. Chang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC 27708
- Center for Biologically Inspired Materials and Material Systems, Duke University, Durham NC 27708
| | - Nehal I. Abu-Lail
- Chemical Engineering and Bioengineering, Washington State University, Pullman WA 99164
| | - Jeffrey M. Coles
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC 27708
- Center for Biologically Inspired Materials and Material Systems, Duke University, Durham NC 27708
- Center for Biomolecular and Tissue Engineering, Duke University, Durham NC 27708
| | - Farshid Guilak
- Center for Biomolecular and Tissue Engineering, Duke University, Durham NC 27708
- Department of Surgery, Duke University, Durham NC 27710
| | - Gregory D. Jay
- Department of Emergency Medicine, Rhode Island Hospital, Providence, RI 02903
| | - Stefan Zauscher
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC 27708
- Center for Biologically Inspired Materials and Material Systems, Duke University, Durham NC 27708
- Center for Biomolecular and Tissue Engineering, Duke University, Durham NC 27708
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Taniguchi D, Dai P, Hojo T, Yamaoka Y, Kubo T, Takamatsu T. Low-energy laser irradiation promotes synovial fibroblast proliferation by modulating p15 subcellular localization. Lasers Surg Med 2009; 41:232-9. [PMID: 19291756 DOI: 10.1002/lsm.20750] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVE Low-energy laser irradiation (low-level laser therapy) (LELI/LLLT/photobiomodulation) has been found to modulate various biological effects, especially those involved in promoting cell proliferation. Synovial fibroblasts are important in maintaining the homeostasis of articular joints and have strong chondrogenetic capacity. Here, we investigated the effect and molecular basis of LELI on synovial fibroblast proliferation. STUDY DESIGN/MATERIALS AND METHODS HIG-82 rabbit synovial fibroblasts were cultured, and laser irradiation (660 nm) was applied at the power density of 40 mW/cm(2) for 2 minutes, corresponding to laser fluence of 4.8 J/cm(2). The effect of LELI on cell proliferation, cell cycle progression, and expression of cyclin-dependent kinase inhibitors (CKIs) were investigated. We also examined whether the effects of LELI on HIG-82 cell proliferation were affected by cAMP content, which is known to influence the cell cycle via inducing CKIs. RESULTS LELI promoted HIG-82 synovial fibroblast proliferation and induced cytoplasmic localization of cyclin-dependent kinase inhibitor p15 (INK4B/CDKN2B). Moreover, the proliferation of HIG-82 synovial fibroblasts was reduced by cAMP, while cAMP inhibitor, SQ22536, induced p15 cytoplasmic localization and as a result, elevated synovial fibroblast proliferation was observed. In addition, the promotive effect of LELI-induced HIG-82 synovial fibroblast proliferation was abolished by cAMP treatment. Our findings suggest that cAMP may be involved in the effect of LELI on synovial fibroblast proliferation. CONCLUSION We revealed the effect and molecular link involved in synovial fibroblast proliferation induced by 660-nm LELI. Our study provides new insights into the mechanisms by which LELI has biological effects on synovial fibroblast proliferation. These insights may contribute to further investigation on biological effects and application of LELI in regenerative medicine.
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Affiliation(s)
- Daigo Taniguchi
- Department of Pathology and Cell Regulation, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
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Fang HW, Su YC, Huang HT, Tsai WB, Liu HL. Investigation of the friction induced conformational change of protein and wear of UHMWPE by a wear process with microfabricated surfaces. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2009. [DOI: 10.1016/j.msec.2008.09.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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106
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Schmidt TA, Plaas AH, Sandy JD. Disulfide-bonded multimers of proteoglycan 4 (PRG4) are present in normal synovial fluids. Biochim Biophys Acta Gen Subj 2009; 1790:375-84. [DOI: 10.1016/j.bbagen.2009.03.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 03/03/2009] [Accepted: 03/16/2009] [Indexed: 12/01/2022]
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Caligaris M, Ateshian GA. Effects of sustained interstitial fluid pressurization under migrating contact area, and boundary lubrication by synovial fluid, on cartilage friction. Osteoarthritis Cartilage 2008; 16:1220-7. [PMID: 18395475 PMCID: PMC2622427 DOI: 10.1016/j.joca.2008.02.020] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 02/22/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This experimental study tests two hypotheses which address outstanding questions in cartilage lubrication: can the friction coefficient remain low under sustained physiological loading conditions? How effective is synovial fluid (SF) in the lubrication of articular cartilage? Based on theory, it is hypothesized that migrating contact areas can maintain elevated cartilage interstitial fluid pressurization, thus a low friction coefficient, indefinitely. It is also hypothesized that the beneficial effects of SF stem from boundary lubrication rather than fluid-film lubrication. DESIGN Five experiments were conducted on immature bovine femoro-tibial joints, to compare the frictional response under migrating vs stationary contact areas; the frictional response in SF vs saline; the role of sliding velocity and the role of congruence on the friction coefficient. RESULTS Migrating contact area could maintain a low friction coefficient under sustained physiological conditions of loading for at least 1 h. SF reduced the friction coefficient by a factor of approximately 1.5 relative to saline. However, interstitial fluid pressurization was far more effective, reducing the friction coefficient by a factor of approximately 60 relative to equilibrium (zero-pressure) conditions. It was confirmed that SF acts as a boundary lubricant. CONCLUSIONS These results emphasize the importance of interstitial fluid pressurization on the frictional response of cartilage. They imply that the mechanical integrity of cartilage must be maintained to produce low friction in articular joints. The more limited effectiveness of SF implies that intra-articular injections of lubricants in degenerated joints may have only limited effectiveness on their tribological properties.
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Affiliation(s)
- M Caligaris
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, United States
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108
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Wong BL, Bae WC, Chun J, Gratz KR, Lotz M, Robert L. Sah. Biomechanics of cartilage articulation: Effects of lubrication and degeneration on shear deformation. ACTA ACUST UNITED AC 2008; 58:2065-74. [DOI: 10.1002/art.23548] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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109
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Elsaid KA, Fleming BC, Oksendahl HL, Machan JT, Fadale PD, Hulstyn MJ, Shalvoy R, Jay GD. Decreased lubricin concentrations and markers of joint inflammation in the synovial fluid of patients with anterior cruciate ligament injury. ARTHRITIS AND RHEUMATISM 2008; 58:1707-15. [PMID: 18512776 PMCID: PMC2789974 DOI: 10.1002/art.23495] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To study the effect of anterior cruciate ligament (ACL) injury on lubricin concentrations in synovial fluid (SF) and its correlation with time postinjury, inflammatory cytokines, lubricin-degrading enzymes, and SF proteoglycan content. METHODS SF samples were obtained from both knees of 30 patients with unilateral ACL insufficiency, 32-364 days postinjury. Lubricin, inflammatory cytokines (interleukin-1beta [IL-1beta], tumor necrosis factor alpha [TNFalpha], and IL-6), and catabolic enzymes (procathepsin B and neutrophil elastase) were measured in SF from injured and contralateral (uninjured) joints, by enzyme-linked immunosorbent assay. Sulfated glycosaminoglycan (sGAG) levels in the SF were measured by Alcian blue binding assay. RESULTS SF lubricin concentrations were significantly (P < 0.001) reduced at an early stage following ACL injury when compared with those in the contralateral joint. Within 12 months, the lubricin concentration in the injured knee (slope = 0.006, SE = 0.00010, P < 0.001) approached that in the contralateral knee, which did not change with time (slope = -0.0002, SE = 0.00050, P = 0.71). TNFalpha levels showed a significant negative relationship with log2 lubricin levels. IL-1beta, TNFalpha, IL-6, procathepsin B, and neutrophil elastase concentrations in SF from injured knees were greater in samples from recently injured knees compared with those that were chronically injured. There were no detectable cytokines or enzymes in the SF of contralateral joints. Concentrations of sGAG were significantly (P = 0.0002) higher in the SF from injured knees compared with the contralateral joints. CONCLUSION The decrease in SF lubricin concentrations following ACL injury may place the joint at an increased risk of wear-induced damage as a consequence of lack of boundary lubrication, potentially leading to secondary osteoarthritis. The decrease in SF lubricin was associated with an increase in levels of inflammatory cytokines.
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Affiliation(s)
- K A Elsaid
- Rhode Island Hospital, Providence, RI 02903, USA
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110
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Chang DP, Abu-Lail NI, Guilak F, Jay GD, Zauscher S. Conformational mechanics, adsorption, and normal force interactions of lubricin and hyaluronic acid on model surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:1183-1193. [PMID: 18181652 DOI: 10.1021/la702366t] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Glycoproteins, such as lubricin, and hyaluronic acid (HA) play a prominent role in the boundary lubrication mechanism in diarthrodial joints. Although many studies have tried to elucidate the lubrication mechanisms of articular cartilage, the molecular details of how lubricin and HA interact with cartilage surfaces and mediate their interaction still remain poorly understood. Here we used model substrates, functionalized with self-assembled monolayers terminating in hydroxyl or methyl groups, (1) to determine the effect of surface chemistry on lubricin and HA adsorption using surface plasmon resonance (SPR) and (2) to study normal force interactions between these surfaces as a function of lubricin and HA concentration using colloidal probe microscopy. We found that lubricin is amphiphilic and adsorbed strongly onto both methyl- and hydroxyl-terminated surfaces. On hydrophobic surfaces, lubricin likely adopts a compact, looplike conformation in which its hydrophobic domains at the N and C termini serve as surface anchors. On hydrophilic surfaces, lubricin likely adsorbs anywhere along its hydrophilic central domain and adopts, with increasing solution concentration, an extended tail-like conformation. Overall, lubricin develops strong repulsive interactions when compressing two surfaces into contact. Furthermore, upon surface separation, adhesion occurs between the surfaces as a result of molecular bridging and chain disentanglement. This behavior is in contrast to that of HA, which does not adsorb appreciably on either of the model surfaces and does not develop significant repulsive interactions. Adhesive forces, particularly between the hydrophobic surfaces, are large and not appreciably affected by HA. For a mixture of lubricin and HA, we observed slightly larger adsorptions and repulsions than those found for lubricin alone. Our experiments suggest that this interaction depends on unspecific physical rather than chemical interactions between lubricin and HA. We speculate that in mediating interactions at the cartilage surface, an important role of lubricin, possibly in conjunction with HA, is one of providing a protective coating on cartilage surfaces that maintains the contacting surfaces in a sterically repulsive state.
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Affiliation(s)
- Debby P Chang
- Department of Mechanical Engineering and Materials Science, Center for Biologically Inspired Materials and Material Systems, Duke University, Durham, NC 27708, USA
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111
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Teeple E, Elsaid KA, Fleming BC, Jay GD, Aslani K, Crisco JJ, Mechrefe AP. Coefficients of friction, lubricin, and cartilage damage in the anterior cruciate ligament-deficient guinea pig knee. J Orthop Res 2008; 26:231-7. [PMID: 17868097 PMCID: PMC2792715 DOI: 10.1002/jor.20492] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The coefficient of friction (COF) of articular cartilage is thought to increase with osteoarthritis (OA) progression, and this increase may occur due to a decrease in lubricin concentration. The objectives of this study were to measure the COF of guinea pig tibiofemoral joints with different stages of OA and to establish relationships between COF, lubricin concentrations in synovial fluid, and degradation status using the Hartley guinea pig model. Both hind limbs from 24 animals were harvested: seven 3-month-old (no OA), seven 12-month-old (mild OA), and 10 that were euthanized at 12 months of age after undergoing unilateral ACL transection at 3 months of age (moderate OA). Contralateral knees served as age-matched controls. COFs of the tibiofemoral joints were measured using a pendulum apparatus. Synovial fluid lavages were analyzed to determine the concentration and integrity of lubricin using ELISA and Western blot, and the overall articular cartilage status was evaluated by histology. The results showed that the mean COF in the ACL-deficient knees was significantly greater than that of the no OA (p < 0.01) and mild OA knees (p < 0.01). Lubricin concentrations in the ACL-deficient knees were significantly lower than that in both of the other groups (p < 0.01). No significant differences in COF or lubricin concentration were found between the no OA and mild OA knees. Histology verified the extent of cartilage damage in each group.
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Affiliation(s)
- Erin Teeple
- Bioengineering Laboratory, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
| | - Khaled A. Elsaid
- Department of Emergency Medicine, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
| | - Braden C. Fleming
- Bioengineering Laboratory, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
- Division of Engineering, Brown University, Providence, RI, USA
| | - Gregory D. Jay
- Department of Emergency Medicine, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
- Division of Engineering, Brown University, Providence, RI, USA
| | - Koosha Aslani
- Bioengineering Laboratory, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
| | - Joseph J. Crisco
- Bioengineering Laboratory, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
- Division of Engineering, Brown University, Providence, RI, USA
| | - Anthony P. Mechrefe
- Bioengineering Laboratory, Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI, USA
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112
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Schmidt TA, Gastelum NS, Han EH, Nugent-Derfus GE, Schumacher BL, Sah RL. Differential regulation of proteoglycan 4 metabolism in cartilage by IL-1alpha, IGF-I, and TGF-beta1. Osteoarthritis Cartilage 2008; 16:90-7. [PMID: 17596975 DOI: 10.1016/j.joca.2007.05.009] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Accepted: 05/14/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To determine (1) if interleukin-1 alpha (IL-1alpha), insulin like growth factor I (IGF-I), and transforming growth factor-beta 1 (TGF-beta1) regulate proteoglycan 4 (PRG4) metabolism in articular cartilage, in terms of chondrocytes expressing PRG4 and PRG4 bound at the articular surface, and (2) if these features of cartilage PRG4 metabolism correlate with its secretion. METHODS Articular cartilage explants were harvested and cultured for 6 days with or without 10% fetal bovine serum (FBS), alone, or with the addition of 10ng/ml IL-1alpha, 300ng/ml IGF-I, or 10ng/ml TGF-beta1. PRG4 expression by chondrocytes in the cartilage disks was assessed by immunohistochemistry (IHC). PRG4 bound to the articular surface of disks was quantified by extraction and enzyme-linked immunosorbent assay (ELISA). PRG4 secreted into culture medium was quantified by ELISA and characterized by Western Blot. RESULTS PRG4 expression by chondrocytes near the articular surface was markedly decreased by IL-1alpha, stimulated by TGF-beta1, and not affected by IGF-I. The level of PRG4 accumulation in the culture medium was correlated with the number of chondrocytes expressing PRG4. The amount of PRG4 bound at the articular surface was modulated by incubation in medium including FBS, but did not correlate with levels of PRG4 secretion. CONCLUSIONS Cartilage secretion of PRG4 is highly regulated by certain cytokines and growth factors, in part through alteration of the number of PRG4-secreting chondrocytes near the articular surface. The biochemical milieu may regulate the PRG4 content of synovial fluid during cartilage injury or repair.
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Affiliation(s)
- T A Schmidt
- Department of Bioengineering and Whitaker Institute of Biomedical Engineering, University of California-San Diego, La Jolla, CA 92093-0412, USA
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113
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Jay GD, Torres JR, Rhee DK, Helminen HJ, Hytinnen MM, Cha CJ, Elsaid K, Kim KS, Cui Y, Warman ML. Association between friction and wear in diarthrodial joints lacking lubricin. ACTA ACUST UNITED AC 2007; 56:3662-9. [PMID: 17968947 PMCID: PMC2688668 DOI: 10.1002/art.22974] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Objective The glycoprotein lubricin (encoded by the gene Prg4) is secreted by surface chondrocytes and synovial cells, and has been shown to reduce friction in vitro. In contrast to man-made bearings, mammalian diarthrodial joints must endogenously produce friction-reducing agents. This study was undertaken to investigate whether friction is associated with wear. Methods The lubricating ability of synovial fluid (SF) samples from humans with genetic lubricin deficiency was tested in vitro. The coefficient of friction in the knee joints of normal and lubricin-null mice was measured ex vivo; these joints were also studied by light and electron microscopy. Atomic force microscopy was used to image and measure how lubricin reduces friction in vitro. Results SF lacking lubricin failed to reduce friction in the boundary mode. Joints of lubricin-null mice showed early wear and higher friction than joints from their wild-type counterparts. Lubricin self-organized and reduced the work of adhesion between apposing asperities. Conclusion These data show that friction is coupled with wear at the cartilage surface in vivo. They imply that acquired lubricin degradation occurring in inflammatory joint diseases predisposes the cartilage to damage. Lastly, they suggest that lubricin, or similar biomolecules, will have applications in man-made devices in which reducing friction is essential.
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Affiliation(s)
- Gregory D Jay
- Brown University, Department of Emergency Medicine, Providence, Rhode Island 02903, USA.
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114
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Coles JM, Blum JJ, Jay GD, Darling EM, Guilak F, Zauscher S. In situ friction measurement on murine cartilage by atomic force microscopy. J Biomech 2007; 41:541-8. [PMID: 18054362 PMCID: PMC2274896 DOI: 10.1016/j.jbiomech.2007.10.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 09/16/2007] [Accepted: 10/19/2007] [Indexed: 11/20/2022]
Abstract
Articular cartilage provides a low-friction, wear-resistant surface for the motion of diarthrodial joints. The objective of this study was to develop a method for in situ friction measurement of murine cartilage using a colloidal probe attached to the cantilever of an atomic force microscope. Sliding friction was measured between a chemically functionalized microsphere and the cartilage of the murine femoral head. Friction was measured at normal loads ranging incrementally from 20 to 100 nN with a sliding speed of 40 microm/s and sliding distance of 64 microm. Under these test conditions, hydrostatic pressurization and biphasic load support in the cartilage were minimized, providing frictional measurements that predominantly reflect boundary lubrication properties. Friction coefficients measured on murine tissue (0.25+/-0.11) were similar to those measured on porcine tissue (0.23+/-0.09) and were in general agreement with measurements of boundary friction on cartilage by other researchers. Using the colloidal probe as an indenter, the elastic mechanical properties and surface roughness were measured in the same configuration. Interfacial shear was found to be the principal mechanism of friction generation, with little to no friction resulting from plowing forces, collision forces, or energy losses due to normal deformation. This measurement technique can be applied to future studies of cartilage friction and mechanical properties on genetically altered mice or other small animals.
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Affiliation(s)
- Jeffrey M. Coles
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC
- Center for Biomolecular and Tissue Engineering, Duke University, Durham, NC
| | - Jason J. Blum
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC
| | - Gregory D. Jay
- Department of Emergency Medicine and Division of Engineering Brown University, Providence, RI
| | - Eric M. Darling
- Department of Surgery, Duke University Medical Center, Durham NC
- Center for Biomolecular and Tissue Engineering, Duke University, Durham, NC
| | - Farshid Guilak
- Department of Surgery, Duke University Medical Center, Durham NC
- Center for Biomolecular and Tissue Engineering, Duke University, Durham, NC
| | - Stefan Zauscher
- Department of Mechanical Engineering and Materials Science, Duke University, Durham NC
- Center for Biomolecular and Tissue Engineering, Duke University, Durham, NC
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115
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Niikura T, Reddi AH. Differential regulation of lubricin/superficial zone protein by transforming growth factor beta/bone morphogenetic protein superfamily members in articular chondrocytes and synoviocytes. ACTA ACUST UNITED AC 2007; 56:2312-21. [PMID: 17599751 DOI: 10.1002/art.22659] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To investigate the role of transforming growth factor beta (TGFbeta)/bone morphogenetic protein (BMP) superfamily members on accumulation of superficial zone protein (SZP) in articular chondrocytes and synoviocytes. METHODS Chondrocytes and synoviocytes were isolated from articular cartilage and synovium from calf stifle joints and cultured as monolayers in serum-free chemically defined medium. Articular chondrocytes were isolated from 3 distinct zones of the cartilage: superficial, middle, and deep. Accumulation of SZP in the culture medium in response to various members of the TGFbeta/BMP superfamily was demonstrated by immunoblotting and quantified by enzyme-linked immunosorbent assay. RESULTS TGFbeta stimulated SZP accumulation in both superficial zone chondrocytes and synoviocytes. The 3 isoforms of TGFbeta elicited a similar dose response. Inhibition of TGFbeta receptor type I kinase by the specific inhibitor SB431542 abolished the TGFbeta-stimulated accumulation of SZP. BMPs up-regulated SZP accumulation in the superficial zone; however, the magnitude of the effects was not as great as was observed with TGFbeta. There was an additive action between TGFbeta and BMP on SZP accumulation. The response of synoviocytes to BMP was stronger than that of superficial zone chondrocytes. Activin up-regulated SZP accumulation in synoviocytes, but not in chondrocytes. CONCLUSION TGFbeta is a critical regulator of SZP accumulation in both superficial zone articular chondrocytes and synoviocytes. TGFbeta and BMP have an additive effect. Synoviocytes are more sensitive to BMP family members and activins than are superficial zone articular chondrocytes. Thus, regulation of SZP accumulation by TGFbeta /BMP superfamily members is regulated differently in articular chondrocytes and synoviocytes.
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Affiliation(s)
- Takahiro Niikura
- University of California, Davis School of Medicine, Sacramento, CA 95817, USA
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116
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Zhang D, Johnson LJ, Hsu HP, Spector M. Cartilaginous deposits in subchondral bone in regions of exposed bone in osteoarthritis of the human knee: histomorphometric study of PRG4 distribution in osteoarthritic cartilage. J Orthop Res 2007; 25:873-83. [PMID: 17343281 DOI: 10.1002/jor.20344] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective of this study was to identify and characterize cartilaginous deposits aggregates in the subchondral bone in areas of the human osteoarthritic knee with exposed bone. A specific aim was to determine the distribution of the joint lubrication molecule, lubricin/superficial zone protein [referred to by its gene, proteoglycan4 (PRG4)], in these cartilaginous deposits and in osteoarthritic cartilage. This work was carried out in the context of assessing the potential contribution of these chondrocyte aggregates for joint resurfacing in certain cartilage repair procedures. The discarded bone cuts of femoral condyles and tibial plateaus were collected from 11 patients with advanced osteoarthritis (OA) of the knee during total knee arthroplasty; 9 women and 2 men with a mean age of 68 years. Sections of paraffin-embedded tissue were stained with Safranin-O, and with antibodies to type II collagen, alpha-smooth muscle actin (SMA), and PRG4. Chondrocyte aggregates were found in the subchondral bone of regions of exposed bone in sections from five individuals. The average diameter of cartilaginous aggregates was 152 microm, and the average depth of the aggregates below the surface was about 475 microm. Most aggregates were fibrocartilaginous and stained positive for type II collagen. Of interest was the finding that the cartilaginous deposits and osteoarthritic cartilage contained PRG4. Only a small percentage of chondrocytes stained positive for SMA. Cartilaginous deposits containing chondrocyte aggregates exist in subchondral bone in regions of exposed bone in some patients with advanced OA of the knee. These cells may be able to contribute to the resurfacing of the joint in certain cartilage repair procedures.
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Affiliation(s)
- Dong Zhang
- Tissue Engineering, VA Boston Healthcare System, Orthopaedic Research Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02130, USA
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117
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Jay GD, Torres JR, Warman ML, Laderer MC, Breuer KS. The role of lubricin in the mechanical behavior of synovial fluid. Proc Natl Acad Sci U S A 2007; 104:6194-9. [PMID: 17404241 PMCID: PMC1851076 DOI: 10.1073/pnas.0608558104] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Synovial fluid is a semidilute hyaluronate (HA) polymer solution, the rheology of which depends on HA-protein interactions, and lubricin is a HA-binding protein found in synovial fluid and at cartilage surfaces, where it contributes to boundary lubrication under load. Individuals with genetic deficiency of lubricin develop precocious joint failure. The role of lubricin in synovial fluid rheology is not known. We used a multiple-particle-tracking microrheology technique to study the molecular interactions between lubricin and HA in synovial fluid. Particles (200 nm mean diameter) embedded in normal and lubricin-deficient synovial fluid samples were tracked separately by using multiple-particle-tracking microrheology. The time-dependent ensemble-averaged mean-squared displacements of all of the particles were measured over a range of physiologically relevant frequencies. The mean-squared displacement correlation with time lag had slopes with values of unity for simple HA solutions and for synovial fluid from an individual who genetically lacked lubricin, in contrast to slopes with values less than unity (alpha approximately 0.6) for normal synovial fluid. These data correlated with bulk rheology studies of the same samples. We found that the subdiffusive and elastic behavior of synovial fluid, at physiological shear rates, was absent in fluid from a patient who lacks lubricin. We conclude that lubricin provides synovial fluid with an ability to dissipate strain energy induced by mammalian locomotion, which is a chondroprotective feature that is distinct from boundary lubrication.
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Affiliation(s)
- G D Jay
- Division of Engineering and Department of Emergency Medicine, Brown University, Providence, RI 02912, USA.
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118
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Schmidt TA, Gastelum NS, Nguyen QT, Schumacher BL, Sah RL. Boundary lubrication of articular cartilage: Role of synovial fluid constituents. ACTA ACUST UNITED AC 2007; 56:882-91. [PMID: 17328061 DOI: 10.1002/art.22446] [Citation(s) in RCA: 355] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE To determine whether the synovial fluid (SF) constituents hyaluronan (HA), proteoglycan 4 (PRG4), and surface-active phospholipids (SAPL) contribute to boundary lubrication, either independently or additively, at an articular cartilage-cartilage interface. METHODS Cartilage boundary lubrication tests were performed with fresh bovine osteochondral samples. Tests were performed using graded concentrations of SF, HA, and PRG4 alone, a physiologic concentration of SAPL, and various combinations of HA, PRG4, and SAPL at physiologic concentrations. Static (mu(static, Neq)) and kinetic (<mu(kinetic, Neq)>) friction coefficients were calculated. RESULTS Normal SF functioned as an effective boundary lubricant both at a concentration of 100% (<mu(kinetic, Neq)> = 0.025) and at a 3-fold dilution (<mu(kinetic, Neq)> = 0.029). Both HA and PRG4 contributed independently to a low mu in a dose-dependent manner. Values of <mu(kinetic, Neq)> decreased from approximately 0.24 in phosphate buffered saline to 0.12 in 3,300 mug/ml HA and 0.11 in 450 mug/ml PRG4. HA and PRG4 in combination lowered mu further at the high concentrations, attaining a <mu(kinetic, Neq)> value of 0.066. SAPL at 200 mug/ml did not significantly lower mu, either independently or in combination with HA and PRG4. CONCLUSION The results described here indicate that SF constituents contribute, individually and in combination, both at physiologic and pathophysiologic concentrations, to the boundary lubrication of apposing articular cartilage surfaces. These results provide insight into the nature of the boundary lubrication of articular cartilage by SF and its constituents. They therefore provide insight regarding both the homeostatic maintenance of healthy joints and pathogenic processes in arthritic disease.
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119
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Abstract
Articular cartilage injury and degeneration is a frequent occurrence in synovial joints. Treatment of these articular cartilage lesions are a challenge because this tissue is incapable of quality repair and/or regeneration to its native state. Nonoperative treatments endeavor to control symptoms, and include anti-inflammatory medication, viscosupplementation, bracing, orthotics, and activity modification. Techniques to stimulate the intrinsic repair (fibrocartilage) process include drilling, abrasion, and microfracture of the subchondral bone. Currently, the clinical biologic approaches to treat cartilage defects include autologous chondrocyte implantation, periosteal transfer, and osteochondral autograft or allograft transplantation. Newer strategies employing tissue engineering being studied involve the use of combinations of progenitor cells, bioactive factors, and matrices, and the use of focal synthetic devices. Many new and innovative treatments are being explored in this exciting field. However, there is a paucity of prospective, randomized controlled clinical trials that have compared the various techniques, treatment options, indications and efficacy.
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Affiliation(s)
- Timothy M Simon
- Orthopaedic Research Institute and the Southern California Center for Sports Medicine, Long Beach, CA 90806, USA.
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120
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Yang CB, Fang HW, Liu HL, Chang CH, Hsieh MC, Lee WM, Huang HT. Frictional characteristics of the tribological unfolding albumin for polyethylene and cartilage. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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121
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Pun SY, Teng MS, Kim HT. Periodic rewetting enhances the viability of chondrocytes in human articular cartilage exposed to air. ACTA ACUST UNITED AC 2006; 88:1528-32. [PMID: 17075104 DOI: 10.1302/0301-620x.88b11.18091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Desiccation of articular cartilage during surgery is often unavoidable and may result in the death of chondrocytes, with subsequent joint degeneration. This study was undertaken to determine the extent of chondrocyte death caused by exposure to air and to ascertain whether regular rewetting of cartilage could decrease cell death. Macroscopically normal human cartilage was exposed to air for 0, 30, 60 or 120 minutes. Selected samples were wetted in lactated Ringer’s solution for ten seconds every ten or 20 minutes. The viability of chondrocytes was measured after three days by Live/Dead staining. Chondrocyte death correlated with the length of exposure to air and the depth of the cartilage. Drying for 120 minutes caused extensive cell death mainly in the superficial 500 μm of cartilage. Rewetting every ten or 20 minutes significantly decreased cell death. The superficial zone is most susceptible to desiccation. Loss of superficial chondrocytes likely decreases the production of essential lubricating glycoproteins and contributes to subsequent degeneration. Frequent wetting of cartilage during arthrotomy is therefore essential.
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Affiliation(s)
- S Y Pun
- University of California, San Francisco School of Medicine, CA 94143, USA
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122
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Ohno S, Schmid T, Tanne Y, Kamiya T, Honda K, Ohno-Nakahara M, Swentko N, Desai TA, Tanne K, Knudson CB, Knudson W. Expression of superficial zone protein in mandibular condyle cartilage. Osteoarthritis Cartilage 2006; 14:807-13. [PMID: 16563813 PMCID: PMC3182505 DOI: 10.1016/j.joca.2006.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Accepted: 02/02/2006] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Superficial zone protein (SZP) has been shown to function in the boundary lubrication of articular cartilages of the extremities. However, the expression of SZP has not been clarified in mandibular cartilage which is a tissue that includes a thick fibrous layer on the surface. This study was conducted to clarify the distribution of SZP on the mandibular condyle and the regulatory effects of humoral factors on the expression in both explants and fibroblasts derived from mandibular condyle. METHODS The distribution of SZP was determined in bovine mandibular condyle cartilage, and the effects of interleukin-1beta (IL-1beta) and transforming growth factor-beta (TGF-beta) on SZP expression were examined in condyle explants and fibroblasts derived from the fibrous zone of condyle cartilage. RESULTS SZP was highly distributed in the superficial zone of intact condyle cartilage. The SZP expression was up-regulated by TGF-beta in both explants and cultured fibroblasts, whereas the expression was slightly down-regulated by IL-1beta. A significant increase in accumulation of SZP protein was also observed in the culture medium of the fibroblasts treated with TGF-beta. CONCLUSIONS These results suggest that SZP plays an important role in boundary lubrication of mandible condylar cartilage, is synthesized locally within the condyle itself, and exhibits differential regulation by cell mediators relevant to mandibular condyle repairing and pathologies.
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Affiliation(s)
- S Ohno
- Department of Orthodontics and Craniofacial Developmental Biology, Division of Cervico-Gnathostomatology, Hiroshima University Graduate School of Biomedical Sciences, Minami-ku, Hiroshima 734-8553, Japan
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123
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Elsaid KA, Jay GD, Chichester CO. Reduced expression and proteolytic susceptibility of lubricin/superficial zone protein may explain early elevation in the coefficient of friction in the joints of rats with antigen-induced arthritis. ACTA ACUST UNITED AC 2006; 56:108-16. [PMID: 17195213 DOI: 10.1002/art.22321] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To investigate the effect of arthritis development and progression on the integrity and function of lubricin and the relationship of lubricin to cartilage damage in a rat antigen-induced arthritis model. METHODS Arthritis was induced in the right knee joints, using methylated bovine serum albumin and Freund's complete adjuvant. Whole joint friction measurements were performed ex vivo with a modified Stanton pendulum configuration, and coefficients of friction (mu) were determined. Levels of messenger RNA (mRNA) for lubricin, cathepsin B, and interleukin-1beta (IL-1beta) in synovial tissue from control and affected joints were determined by quantitative polymerase chain reaction. Lubricin staining in cartilage was performed using a lubricin-specific monoclonal antibody. RESULTS The mu values in excised right joints following arthritis induction were significantly (P < 0.001) higher than those in excised left joints. Lubricin mRNA expression levels in synovial tissue on days 4 and 7 after arthritis induction were significantly (P < 0.001) lower in the right joints compared with the left joints, whereas levels of cathepsin B and IL-1beta mRNA expression on days 4, 7, and 14 were significantly (P < 0.001) higher in the right joints than the left joints. Lubricin staining was diminished in cartilage from the right joints compared with the left joints. CONCLUSION Elevated coefficients of friction in arthritic joints occur concurrently with enhanced proteolytic degradation by up-regulated cathepsin B and other proteases, as well as decreased lubricin synthesis by synovial fibroblasts and superficial zone chondrocytes. Loss of joint lubrication is an early event in inflammatory arthropathy. Restoring chondroprotection and preventing potential wear-induced cartilage degradation may require lubricin supplementation in synovial fluid.
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MESH Headings
- Adjuvants, Immunologic/pharmacology
- Animals
- Arthritis, Experimental/metabolism
- Arthritis, Experimental/pathology
- Arthritis, Experimental/physiopathology
- Arthritis, Rheumatoid/etiology
- Arthritis, Rheumatoid/metabolism
- Arthritis, Rheumatoid/pathology
- Arthritis, Rheumatoid/physiopathology
- Cartilage, Articular/metabolism
- Cartilage, Articular/pathology
- Cartilage, Articular/physiopathology
- Cathepsin B/genetics
- Cathepsin B/metabolism
- Chondrocytes/metabolism
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Friction
- Gene Expression
- Glycoproteins/genetics
- Glycoproteins/metabolism
- Humans
- Interleukin-1beta/genetics
- Interleukin-1beta/metabolism
- Joints/metabolism
- Joints/pathology
- Joints/physiopathology
- Lubrication
- Male
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Lew
- Reverse Transcriptase Polymerase Chain Reaction
- Synovial Membrane/metabolism
- Synovial Membrane/pathology
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Rhee DK, Marcelino J, Al-Mayouf S, Schelling DK, Bartels CF, Cui Y, Laxer R, Goldbach-Mansky R, Warman ML. Consequences of Disease-causing Mutations on Lubricin Protein Synthesis, Secretion, and Post-translational Processing. J Biol Chem 2005; 280:31325-32. [PMID: 16000300 DOI: 10.1074/jbc.m505401200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lubricin, a protein product of the gene PRG4, is a secreted mucin-like proteoglycan that is a major lubricant in articulating joints. Mutations in PRG4 cause the autosomal recessive, human disorder camptodactyly-arthropathy-coxa vara-pericarditis syndrome. We developed rabbit polyclonal antibodies against human lubricin to determine the consequence of disease-causing mutations at the protein level and to study the protein's normal post-translational processing. Antiserum generated against an epitope in the amino-terminal portion of lubricin detected protein in wild-type synovial fluid and in conditioned media from wild-type cultured synoviocytes. However, the antiserum did not detect lubricin in synovial fluid or cultured synoviocytes from several patients with frameshift or nonsense mutations in PRG4. Antiserum generated against an epitope in the protein's carboxyl-terminal, hemopexin-like domain identified a post-translational cleavage event in wild-type lubricin, mediated by a subtilisin-like proprotein convertase (SPC). Interestingly, in contrast to wild-type lubricin, one disease-causing mutation that removes the last 8 amino acids of the protein, including a conserved cysteine residue, was not cleaved within the hemopexin-like domain when expressed in COS-7 cells. This suggests that formation of an intrachain disulfide bond is required for SPC-mediated cleavage and that SPC-mediated cleavage is essential to protein function.
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Affiliation(s)
- David K Rhee
- Department of Genetics and Center for Human Genetics, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Cleveland, Ohio 44106, USA
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