Abstract | OBJECTIVE: METHODS: RESULTS:
Hexosaminidase was found to be the dominant enzyme released by chondrocytes into the extracellular compartment. Stimulation of chondrocytes with interleukin-1beta resulted in a selective increase of the extracellular hexosaminidase activity and, to a lesser degree, of the extracellular beta-galactosidase activity, without significant changes in the activity of the other studied enzymes. Analysis of the pH dependency of the enzymatic activities revealed that even at neutral pH, hexosaminidase expressed a measurable activity, much higher than the activity of the other studied enzymes. Chondrocyte apoptosis did not result in increased extracellular glycosidase activities, including hexosaminidase activity. The spectrum of glycosidase and glycoside sulfatase activities in the synovial fluid from patients with osteoarthritis was similar to that in cultured human articular chondrocytes. CONCLUSION: These data support the concept that lysosomal glycosidases, in particular hexosaminidase, represent a distinct subset of cartilage matrix-degrading enzymes that are activated by proinflammatory stimuli.
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Authors | A R Shikhman, D C Brinson, M Lotz |
Journal | Arthritis and rheumatism
(Arthritis Rheum)
Vol. 43
Issue 6
Pg. 1307-14
(Jun 2000)
ISSN: 0004-3591 [Print] United States |
PMID | 10857789
(Publication Type: Journal Article)
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Chemical References |
- Glycosaminoglycans
- Glycosides
- Inflammation Mediators
- Interleukin-1
- Sulfatases
- Glycoside Hydrolases
- beta-N-Acetylhexosaminidases
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Topics |
- Apoptosis
(physiology)
- Cartilage, Articular
(drug effects, enzymology, pathology)
- Cells, Cultured
- Chondrocytes
(drug effects, enzymology, physiology)
- Extracellular Space
(enzymology)
- Glycosaminoglycans
(metabolism)
- Glycoside Hydrolases
(metabolism)
- Glycosides
(metabolism)
- Homeostasis
(physiology)
- Humans
- Hydrogen-Ion Concentration
- Inflammation Mediators
(pharmacology)
- Interleukin-1
(pharmacology)
- Osteoarthritis
(enzymology, pathology)
- Reference Values
- Sulfatases
(metabolism)
- Synovial Fluid
(enzymology)
- beta-N-Acetylhexosaminidases
(metabolism)
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