Regulation of plasminogen activation, matrix metalloproteinases and urokinase-type plasminogen activator-mediated extracellular matrix degradation in human osteosarcoma cell line MG63 by interleukin-1 alpha
article
Plasmin-mediated extracellular proteolysis has been implicated in the degradation of bone in normal and pathological conditions. Normal and malignant osteoblasts can produce both tissue-type plasminogen activator (t- PA) and urokinase-type plasminogen activator (u-PA). We have used the osteosarcoma cell line MG63 to address the question of whether the enhanced bone turnover in osteosarcomas is mediated by t-PA or by u-PA and to study the effect of the cytokine interleukin-1α (IL-1α), known to influence bone degradation, on the plasminogen activator production and extracellular matrix degradation in malignant osteoblastic cells. Furthermore, the effect of IL- 1α on the synthesis of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) was analyzed. u-PA production by MG63 was high (approximately 180 ng/106 cells/2,4 h). Also t-PA and PAI-1 production was observed. u-PA production was rapidly increased in MG63 by IL-1α (10 ng/ml), whereas an effect on t-PA production was only found after a prolonged incubation and hardly any effect of IL-1α on PAI-1 production was observed. mRNA analysis revealed similar effects. u-PA receptor (u-PAR) mRNA was detectable in MG63 cells and could be increased by IL-1α after 24 h. In MG63, u-PA-mediated extracellular matrix degradation was detectable, and IL-1α increased the u- PA-mediated matrix degradation (approximately 2-fold). Under control conditions in MG63, only MMP-2, TIMP-1, and TIMP-2 mRNA could be observed. After the addition of IL-1α, a very rapid increase in MMP-1 and MMP-3 mRNA could be observed as well as a moderate increase in TIMP-1 mRNA. The presence of MMP-2 was demonstrated by gelatin zymography. These results show that IL- 1α can stimulate u-PA production and can regulate extracellular proteolytic activity mainly via u-PA induction in the MG63 osteosarcoma cell line. Furthermore, IL-1α has a strong stimulating effect on the production of MMP- 1 and MMP-3. These findings suggest that u-PA and possibly MMP-1 and MMP-3 play an important role in the process of bone turnover in osteosarcomas. Chemicals/CAS: collagenase, 37288-86-1, 39433-96-0, 9001-12-1; gelatinase, 9040-48-6; metalloproteinase, 81669-70-7; plasminogen, 9001-91-6; stromelysin, 79955-99-0; tissue inhibitor of metalloproteinase, 97837-28-0; urokinase, 139639-24-0; Interleukin-1; Metalloendopeptidases, EC 3.4.24; Plasminogen Activators, EC 3.4.21.-; Plasminogen Inactivators; Urinary Plasminogen Activator, EC 3.4.21.73
Topics
collagenasegelatinaseinterleukin 1alphamessenger rnametalloproteinaseplasminogenstromelysintissue inhibitor of metalloproteinaseurokinaseanimal cellanimal tissuearticlebone matrixbone turnovercalvariacattlecontrolled studyextracellular matrixhumanhuman cellmousenonhumanosteolysisosteosarcomaprotein degradationExtracellular MatrixHumanInterleukin-1MetalloendopeptidasesOsteoblastsOsteosarcomaPlasminogen ActivatorsPlasminogen InactivatorsSupport, Non-U.S. Gov'tTumor Cells, CulturedUrinary Plasminogen Activator
TNO Identifier
232826
ISSN
08840431
Source
Journal of Bone and Mineral Research, 10(9), pp. 1374-1384.
Pages
1374-1384
Files
To receive the publication files, please send an e-mail request to TNO Repository.