Differential regulation of cytokine-induced MMP-1 and MMP-13 expression by p38 kinase inhibitors in human chondrosarcoma cells: potential role of Runx2 in mediating p38 effects.
OBJECTIVE
To investigate mitogen activated protein (MAP) kinase pathways for their ability to differentially regulate the expression of matrix metalloprotease (MMP)-1 and -13 in human chondrosarcoma cells using pathway-selective inhibitors.


METHODS
Human chondrosarcoma cell lines (SW1353 and JJ012) and human articular chondrocytes (HACs) were treated with cytokines (IL-1beta and TNFalpha) and the expression of MMP-1 and -13 was analyzed. The effects of MAP kinase inhibitors on cytokine-induced expression of MMP-1 and -13 were evaluated using ELISA and Western blot analyses. The possible involvement of the Runx2 pathway in mediating p38 effects on MMP-13 expression was analyzed using promoter-reporter assays, ELISA and immunoprecipitation analyses.


RESULTS
IL-1beta and TNFalpha strongly induced the expression of MMP-1 and -13 in SW1353 cells and HACs, whereas only TNFalpha was found to induce the expression of these two MMPs in JJ012 cells. Cytokine treatment did not result in a significant increase in the activity of MMPs because of the excess production of endogenous tissue inhibitors of metalloproteases (TIMPs). Treatment with p38 kinase inhibitors (SB203580 and SB242235) strongly inhibited cytokine-induced MMP-13 expression in a dose-dependent fashion while having a somewhat weaker inhibitory effect on MMP-1 expression. In contrast, inhibitors of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) pathways did not inhibit the expression of either MMP. Overexpression of Runx2 robustly stimulated the transcriptional activation of MMP-13 but had no effect on MMP-1 expression. Furthermore, IL-1beta induced the phosphorylation of Runx2, and this effect was blocked by a p38 kinase inhibitor. Our data suggest that Runx2 is likely to be a key downstream mediator of p38 effects in the differential regulation of IL-1beta induced MMP-13 expression.


CONCLUSIONS
These studies demonstrate the differential inhibition of cytokine-induced MMP-1 and -13 expression by p38 kinase inhibitors in human chondrosarcoma cells. Our studies also suggest the involvement of Runx2, at least in part, in mediating the effects of p38 on MMP-13 expression.
Musculoskeletal Research, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN 46285, USA.
Yong
Y
Pei
Anita
A
Harvey
Xiao-Peng
XP
Yu
Srinivasan
S
Chandrasekhar
Kannan
K
Thirunavukkarasu
D015153:Blotting, Western / Q000379:methods; D045744:Cell Line, Tumor; D002813:Chondrosarcoma / Q000201:enzymology* / Q000276:immunology*; D050659:Core Binding Factor Alpha 1 Subunit / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D047468:Immunoprecipitation; D053583:Interleukin-1beta / Q000494:pharmacology*; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection / Q000379:methods; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors*
D050659:Core Binding Factor Alpha 1 Subunit; D053583:Interleukin-1beta; C493709:RUNX2 protein, human; D048051:p38 Mitogen-Activated Protein Kinases; D053509:Matrix Metalloproteinase 13; D020781:Matrix Metalloproteinase 1