Homeostasis of the extracellular matrix of normal and osteoarthritic human articular cartilage chondrocytes in vitro

Proteoglycan biosynthesis by human osteochondrophytic spurs (osteophytes) obtained from osteoarthritic femoral heads at the time of surgical joint replacement was studied under defined culture conditions in vitro. Osteophytes were primarily present in two anatomic locations, marginal and epi-articular. Minced tissue slices were incubated in the presence of [35S]sulphate or [14C]glucosamine. Osteophytes incorporated both labelled precursors into proteoglycan, which was subsequently characterized by CsCl-isopycnic-density-gradient ultracentrifugation and chromatography on Sepharose CL-2B. The material extracted with 0.5m-guanidinium chloride showed 78.1% of [35S]sulphate in the A1 fraction after centrifugation. Only 23.0% of the [35S]sulphate in this A1 fraction was eluted in the void volume of Sepharose CL-2B under associative conditions. About 60–80% of the [35S]sulphate in the tissue 4m-guanidinium chloride extract was associated with monomeric proteoglycan (fraction D1). The average partition coefficient (Kav.) of the proteoglycan monomer on Sepharose CL-2B was 0.28–0.33. Approx. 12.4% of this monomer formed stable aggregates with high-molecular-weight hyaluronic acid in vitro. Sepharose CL-2B chromatography of fractions with lower buoyant densities (fractions D2–D4) demonstrated elution profiles on Sepharose CL-2B substantially different than that of fraction D1, indicative of the polydisperse nature of the newly synthesized proteoglycan. Analysis of the composition and chain size of the glycosaminoglycans showed the following: (1) preferential elution of both [35S]sulphate and [14C]glucosamine in the 0.5m-LiCl fraction on DEAE-cellulose; (2) the predominant sulphated glycosaminoglycan was chondroitin 6-sulphate (60–70%), with 9–11% keratan sulphate in the monomer proteoglycan; (3) Kav. values of 0.38 on Sephadex G-200 and 0.48 on Sepharose CL-6B were obtained with papain-digested and NaBH4-treated D1 monomer respectively. A comparison of the synthetic with endogenous glycosaminoglycans indicated similar types. These studies indicated that human osteophytes synthesized in vitro sulphated proteoglycans with some characteristics similar to those of mature human articular cartilage, notably in the size of their proteoglycan monomer and predominance of chondroitin 6-sulphate. They differed from articular cartilage primarily in the lack of substantial quantities of keratan sulphate and aggregation properties associated with monomer interaction with hyaluronic acid.

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Recombinant human gelsolin promotes the migration of human articular cartilage chondrocytes by regulating gene expression in vitro

Osteoarthritis and Cartilage Open ◽

10.1016/j.ocarto.2020.100124 ◽

2020 ◽

Vol 2 (4) ◽

pp. 100124

Author(s):

Jessica Feldt ◽

Jessica Welss ◽

Verena Schropp ◽

Kolja Gelse ◽

Michael Tsokos ◽

...

Keyword(s):

Gene Expression ◽

Articular Cartilage ◽

Human Articular Cartilage

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The response of elderly human articular cartilage to mechanical stimuli in vitro

Osteoarthritis and Cartilage ◽

10.1016/j.joca.2005.07.002 ◽

2005 ◽

Vol 13 (12) ◽

pp. 1084-1091 ◽

Cited By ~ 17

Author(s):

M.S. Plumb ◽

R.M. Aspden

Keyword(s):

Articular Cartilage ◽

Human Articular Cartilage ◽

Mechanical Stimuli

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Association of magnesium whitlockite crystals with lipid components of the extracellular matrix in human articular cartilage

Osteoarthritis and Cartilage ◽

10.1016/s1063-4584(97)80004-0 ◽

1997 ◽

Vol 5 (2) ◽

pp. 107-119 ◽

Cited By ~ 6

Author(s):

C.A. Scotchford ◽

S.Y. Ali

Keyword(s):

Extracellular Matrix ◽

Articular Cartilage ◽

Human Articular Cartilage ◽

Lipid Components

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Characterization of proteins from human synovium and mononuclear leucocytes that induce resorption of cartilage proteoglycan in vitro

Biochemical Journal ◽

10.1042/bj2090337 ◽

1983 ◽

Vol 209 (2) ◽

pp. 337-344 ◽

Cited By ~ 51

Author(s):

J Saklatvala ◽

S J Sarsfield ◽

L M C Pilsworth

Keyword(s):

Articular Cartilage ◽

Synovial Tissue ◽

Gel Filtration ◽

Human Articular Cartilage ◽

Nasal Cartilage ◽

Cartilage Proteoglycan ◽

Mononuclear Leucocytes ◽

Culture Supernatants

Both human synovial tissue in culture and lectin-stimulated mononuclear leucocytes produced a protein that induced proteoglycan resorption in explants of bovine nasal cartilage and human articular cartilage. On gel filtration the protein had Mr 16000-20000 and on isoelectric focusing its pI was 5.2-5.3. The protein corresponded to catabolin, which has previously been identified as a product of cultured porcine synovial tissue and mononuclear leucocytes. The action of partially purified human catabolin was not inhibited by cortisol, although the activity of the leucocyte supernatants from which it had been isolated was inhibited. For this reason it is not possible to be sure that the active factor detected in the bioassay of the crude leucocyte culture supernatants is in fact catabolin.

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Localization of hyaluronic acid in human articular cartilage.

Journal of Histochemistry & Cytochemistry ◽

10.1177/42.4.8126377 ◽

1994 ◽

Vol 42 (4) ◽

pp. 513-522 ◽

Cited By ~ 24

Author(s):

A Asari ◽

S Miyauchi ◽

S Kuriyama ◽

A Machida ◽

K Kohno ◽

...

Keyword(s):

Extracellular Matrix ◽

Hyaluronic Acid ◽

Articular Cartilage ◽

Dermatan Sulfate ◽

Keratan Sulfate ◽

Human Articular Cartilage ◽

Middle Zone ◽

Deep Zone ◽

Weak Staining ◽

Pre Treatment

To demonstrate localization of hyaluronic acid (HA) in articular cartilage of the human femur, biotinylated HA-binding region, which specifically binds HA molecules, was applied to the tissue. In sections fixed by 2% paraformaldehyde-2% glutaraldehyde, HA staining was detected in lamina splendens and chondrocytes in the middle zone. By pretreatment with trypsin, intense HA staining appeared in the extracellular matrix of the deep zone and weak staining in the superficial and middle zones. Moreover, pre-treatment with chondroitinase ABC (CHase ABC) intensely enhanced the stainability for HA in the superficial and middle zones and weakly in the deeper zone. Combined pre-treatment of trypsin with CHase ABC abolished intra- and extracellular staining for HA in all zones. By microbiochemical study, the concentrations of HA and dermatan sulfate were high in the middle zone, whereas those of chondroitin sulfate and keratan sulfate were high in the deep zone. These results suggest that HA is abundantly synthesized in and secreted from the chondrocytes, particularly in the middle zone, whereas it is largely masked by proteoglycan constituents in the extracellular matrix.

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