Recombinant matrix metalloproteinase-14 catalytic domain induces apoptosis in human osteoblastic SaOS-2 cells.
Our study previously showed that estrogen and progesterone stimulated the production of matrix metalloproteinase-14 [MMP-14, or also named membrane type matrix metalloproteinses-1 (MT1-MMP)] in osteoblastic cells. MMP-14 was implied to regulate the function of osteoblasts by degrading bone matrix or growth factors, but the mechanism is unclear. Since MMP-14 plays a role primarily through the catalytic domain, and truncated MMP-14 containing the catalytic domain and lacking transmembrane domain can be secreted into medium by cultured cells, our present study was performed to observe the direct effects of recombinant MMP-14 catalytic domain on cultured human osteoblastic osteogenic sarcoma (SaOS)-2 cells. Our data showed that recombinant MMP-14 catalytic domain activated proMMP-2 secreted into media by SaOS-2 cells, and this process was blocked by ethylenediamine tetraacetic acid (EDTA) treatment. Recombinant MMP-14 catalytic domain inhibited the adhesion of SaOS-2 cells to immobilized type I collagen or fibronectin in a dose-dependent manner, and these effects on SaOS-2 cells were abolished by EDTA. Recombinant MMP-14 catalytic domain induced SaOS-2 cells apoptosis in a dose-dependent manner, and apoptosis-inducing activity of MMP-14 catalytic domain was blocked if it was treated with EDTA. In conclusion, we revealed that recombinant MMP-14 catalytic domain induced SaOS-2 cells apoptosis. We also indirectly showed the activity of MMP-14 catalytic domain to degrade extracellular matrix (ECM) in cultures of SaOS-2 cells through Gelatin Zymograms and adhesion assay. This suggests that since adhesion of cells to ECM serves as a survival mechanism in osteoblasts, the catalytic activity of recombinant MMP-14 catalytic domain on matrix proteins contributes to its apoptosis-inducing activity.
Luo
X H
XH
Institute of Endocrinology and Metabolism, The Second Xiangya Hospital of Central South University, Changsha, Hunan, PR China. xianghangluo@21cn.com
Liao
E Y
EY
Liao
H J
HJ
Jin
Y
Y
Zhou
H D
HD
Huang
G
G
D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D020134:Catalytic Domain; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology
D011994:Recombinant Proteins; D004492:Edetic Acid; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases