Induction of matrix metalloproteinases in keratinocytes by cholesteatoma debris and granulation tissue extracts

2000 ◽  
Vol 257 (8) ◽  
pp. 425-429 ◽  
Author(s):  
M. Schmidt ◽  
P. Grünsfelder ◽  
F. Hoppe
Keyword(s):  
Matrix Metalloproteinases ◽  
Granulation Tissue ◽  
Tissue Extracts

The mechanism of aggrecan release from cartilage differs with tissue origin and the agent used to stimulate catabolism

2002 ◽  
Vol 362 (2) ◽  
pp. 465-472 ◽  
Author(s):  
Robert SZTROLOVICS ◽  
Robert J. WHITE ◽  
Peter J. ROUGHLEY ◽  
John S. MORT
Keyword(s):  
Retinoic Acid ◽  
Matrix Metalloproteinases ◽  
Culture Media ◽  
Explant Culture ◽  
Epiphyseal Cartilage ◽  
Human Cartilage ◽  
Nasal Cartilage ◽  
Tissue Extracts ◽  
Significant Release ◽  
Stimulatory Agent

The mechanisms of aggrecan degradation in adult human articular, adult bovine nasal and fetal bovine epiphyseal cartilage in response to either interleukin-1β (IL-1β) or retinoic acid were compared using an explant culture system. Bovine nasal cartilage cultured with either IL-1β or retinoic acid exhibited significant release of glycosaminoglycan (GAG). For both factors, aggrecan proteolysis occurred predominantly at the ‘aggrecanase’ site, with no evidence for the action of matrix metalloproteinases, and resulted in the appearance of the corresponding G1 fragment in tissue extracts and in culture media. In human cartilage, little effect of IL-1β was seen, but abundant release of GAG occurred in the presence of retinoic acid, with evidence of aggrecanase action. Treatment of fetal epiphyseal cartilage with retinoic acid resulted in significant GAG release, whereas treatment with IL-1β did not. In the retinoic acid-treated tissue, however, no evidence for the cleavage of aggrecan in the interglobular region was apparent. Thus, in the fetal system, agents in addition to aggrecanase and matrix metalloproteinases appear to be active. Taken together, these data demonstrate that the pathways utilized for aggrecan catabolism may vary between different cartilages for a given stimulatory agent, and that, for a given tissue, different factors may elicit aggrecan release via different pathways.

Cytokine synergy, collagenases and cartilage collagen breakdown

2003 ◽  
Vol 70 ◽  
pp. 125-133 ◽  
Author(s):  
Tim E. Cawston ◽  
Jenny M. Milner ◽  
Jon B. Catterall ◽  
Andrew D. Rowan
Keyword(s):  
Matrix Metalloproteinases ◽  
Inflammatory Cytokines ◽  
Activator Protein 1 ◽  
Activator Protein ◽  
And Cartilage ◽  
Pro Inflammatory Cytokines

We have investigated proteinases that degrade cartilage collagen. We show that pro-inflammatory cytokines act synergistically with oncastatin M to promote cartilage collagen resorption by the up-regulation and activation of matrix metalloproteinases (MMPs). The precise mechanisms are not known, but involve the up-regulation of c-fos, which binds to MMP promoters at a proximal activator protein-1 (AP-1) site. This markedly up-regulates transcription and leads to higher levels of active MMP proteins.

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