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MMP-13 is induced during chondrocyte hypertrophy
M D'Angelo1, Z Yan, M Nooreyazdan
1Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Journal of Cellular Biochemistry
|April 20, 2000
Summary
Matrix metalloproteinase-13 (MMP-13) is a marker for chondrocyte hypertrophy and cartilage calcification. MMP-13 activation by MMP-2 is crucial for preparing cartilage matrix for endochondral ossification.
Area of Science:
- Biochemistry
- Developmental Biology
- Cell Biology
Background:
- Matrix metalloproteinase-13 (MMP-13) mRNA is associated with cartilage hypertrophy during development.
- This suggests a role for MMP-13 in chondrocyte enlargement and cartilage calcification.
Purpose of the Study:
- To investigate the relationship between MMP-13 expression and the transition to chondrocyte hypertrophy.
- To identify the role of MMP-13 in cartilage maturation and calcification.
Main Methods:
- Chondrocytes from chick embryo sternae were cultured and induced to hypertrophy using ascorbate and bone morphogenetic protein-2 (BMP-2).
- MMP-13 mRNA levels were assessed, and proteinase activity was analyzed using zymography.
- A polyclonal antibody against chick MMP-13 was used for confirmation.
Main Results:
- MMP-13 mRNA levels paralleled type X collagen during hypertrophy.
- MMP-13 mRNA was confirmed as a marker for hypertrophy, being absent in nonhypertrophic chondrocytes.
- MMP-13 protein was detected at 59 kDa, with activity increasing in parallel with MMP-2 during later maturation stages.
Conclusions:
- MMP-13 is a reliable marker for chondrocyte hypertrophy.
- MMP-13 activation by MMP-2 is essential for chondrocyte maturation.
- The combined action of MMP-13 and MMP-2 prepares cartilage matrix for calcification and endochondral ossification.