Effects of indomethacin on the production of matrix metalloproteinase-3 and tissue inhibitor of metalloproteinases-1 by human articular chondrocytes.
OBJECTIVE
To study the action of indomethacin on cartilage catabolic activity by comparing the production of a matrix degrading proteinase and its inhibitor in human articular chondrocyte cultures.


METHODS
Matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in conditioned medium from human articular chondrocyte cultures were measured using a one-step sandwich enzyme immunoassay. TIMP-1 mRNA expression was analyzed by Northern blotting using a 0.6 kb cDNA probe for human TIMP-1.


RESULTS
Human recombinant interleukin 1 beta (IL-1 beta) increased MMP-3 levels in primary chondrocyte cultures. Indomethacin at 10(-5) M inhibited this IL-1 beta stimulation, but had no effect in the therapeutic range (10(-6)-10(-7) M). Low levels of indomethacin (10(-7) M) significantly increased the production of TIMP-1 by chondrocytes. Synthesis of TIMP-1 appeared to be inhibited by prostaglandin E2 (PGE2), since exogenously added PGE2 reversed the stimulating effect of indomethacin on TIMP-1 production. Northern blot analysis showed that 10(-7) M indomethacin increased TIMP-1 mRNA levels in chondrocytes.


CONCLUSIONS
Our findings indicate that low levels of indomethacin can benefit matrix metabolism by affecting the balance of proteinases to their inhibitors in human articular cartilage.
Department of Orthopaedic Surgery, National Defense Medical College, Saitama, Japan.
H
H
Yamada
T
T
Kikuchi
O
O
Nemoto
K
K
Obata
H
H
Sato
M
M
Seiki
M
M
Shinmei
D015152:Blotting, Northern; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D017364:Collagenases / Q000378:metabolism*; D015232:Dinoprostone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D019714:Tissue Inhibitor of Metalloproteinases
D006023:Glycoproteins; D007375:Interleukin-1; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D017364:Collagenases; D019278:Matrix Metalloproteinase 3; D015232:Dinoprostone; D007213:Indomethacin