Immunolocalisation and expression of proteoglycan 4 (cartilage superficial zone proteoglycan) in tendon

Rees, Sarah; Davies, Jennifer R.; Tudor, D.; Flannery, Carl R.; Hughes, Claire E.; Dent, Chris; Caterson, Bruce

doi:10.1016/s0945-053x(02)00056-2

Cited by 114 publications

(106 citation statements)

References 32 publications

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“…Lubricin, also known as superficial zone protein (SZP), megakaryocyte stimulating factor (MSF), hemangiopoietin (HAPO), or proteoglycan 4 (PRG4), has been found in a number of tissues, including synovial fluid, [1][2][3] superficial zone of cartilage, 4 synovial membrane, 5 tendon, 6 and meniscus, 7 as well as the urine of patients with aplastic anemia and of patients undergoing bone marrow transplantation during a period of acute thrombocytopenia. 8 Its best-known physical characteristic is its excellent boundary lubricating ability.…”

Section: Introductionmentioning

confidence: 99%

Expression and mapping of lubricin in canine flexor tendon

et al. 2006

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Matrix composition and the biomechanical environment are intimately interdependent in most connective tissues. Lubricin has many distinct biological functions, including lubrication, antiadhesion, and cytoprotection in cartilage, tendons, and other tissues. This study investigated the distribution of lubricin in the canine flexor digitorum profundus (FDP) tendon by immunohistochemistry. Lubricin was found both on the tendon surface and at the interface of collagen fiber bundles within the tendon, where the cells are subjected to shear force in addition to tension and compression. The expression of lubricin in regions of the canine flexor tendon that differ in mechanical or nutritional environment was also investigated using RT-PCR. Six N-terminal splicing variants were identified from six distinct anatomical regions of flexor tendon. The variants with larger sizes were noted in regions subjected to significant shear and compressive forces. Lubricin is ubiquitous in the FDP tendon, with variations in distribution and splicing that appear to correspond to discrete anatomic locations that differ by mechanical or nutritional environment. ß

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Section: Introductionmentioning

confidence: 99%

Expression and mapping of lubricin in canine flexor tendon

et al. 2006

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“…The remarkable frictional properties of the tissue are achieved, at least in part, by lubricin, a mucin-like glycoprotein present in synovial fluid (1) and localized at the surface of joint tissue (2)(3)(4). Lubricin is expressed by the proteoglycan 4 (PRG4) gene (5) and is synthesized by a number of tissues, including cartilage, meniscus, intervertebral disc, and tendon (2)(3)(4)(6)(7)(8)(9). There are numerous posttranslated products of the PRG4 gene (5,(10)(11)(12)(13)(14)(15)(16), including megakaryocytestimulating factor precursor and superficial zone protein, which have significant homology to lubricin (11,15), and as such, we will refer to them collectively as lubricin.…”

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confidence: 99%

Alteration of articular cartilage frictional properties by transforming growth factor β, interleukin‐1β, and oncostatin M

Gleghorn¹,

Jones²,

Flannery³

et al. 2009

Arthritis & Rheumatism

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Objective. To evaluate the functional effects of transforming growth factor ␤1 (TGF␤1), interleukin-1␤ (IL-1␤), and oncostatin M (OSM) on the frictional properties of articular cartilage and to determine the role of cytokine-mediated changes in cartilage frictional properties by extracting and redepositing lubricin on the surface of cartilage explants.Methods. Neonatal bovine cartilage explants were cultured in the presence or absence of 10 ng/ml of TGF␤1, IL-1␤, or OSM over 48 hours. Boundary lubrication tests were conducted to determine the effects of endogenously produced surface localized lubricin and of exogenous lubricin at the tissue surface and in the lubricant solution. The initial friction coefficient ( 0 ), equilibrium friction coefficient ( eq ), and Young's modulus (E Y ) were determined from the temporal load data.Results. IL-1␤ and OSM decreased tissue glycosaminoglycan (GAG) content by ϳ20% over 48 hours and decreased E Y to a similar extent (11-17%), but TGF␤ did not alter GAG content or E Y . Alterations in proteoglycan content corresponded to changes in 0 , but endogenous lubricin decreased boundary mode eq . The addition of exogenous lubricin, either localized at the tissue surface or in the lubricating solution, did not modulate 0 , but it did lower eq in cytokine-treated cartilage.Conclusion. This study provides new insight into the functional consequences of cytokine-mediated changes in friction coefficient. In combination with established pathways of cytokine-mediated lubricin metabolism, these data provide evidence of distinct biochemical origins of boundary and biphasic pressuremediated lubrication mechanisms in cartilage, with boundary lubrication regulated by surface accumulation of lubricants and biphasic lubrication controlled by factors such as GAG content that affect water movement through the tissue.

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“…The presence of lubricin in the extracellular matrix suggested the lubricin released from the tendon cells may be diffusing through the tissue, perhaps to reach the surface. Evidence of the constitutive production of lubricin by cells in the tendons is important in light of some studies suggesting mechanical stimuli regulate lubricin expression [10,23,26,29]. Jones and Flannery [16] also investigated the effects of various cytokines on lubricin expression and suggested transforming growth factor (TGF)-b increased lubricin synthesis, secretion, and cartilage boundary association.…”

Section: Discussionmentioning

confidence: 99%

“…Given lubricin is an antiadhesive protein, it may interfere with cell adhesion to the natural or torn tendon surface [23] and interfere with integrative repair processes [6] required for compete healing.…”

Section: Introductionmentioning

confidence: 99%