Matrix metalloproteinases 2 and 9 are concentrated in the luminal aspect of the cricoid cartilage, diminish with loss of perichondrium, and are reinstated by transforming growth factor beta 3.
OBJECTIVE
We determined the location of matrix metalloproteinases (MMP) 2 and 9, and whether the luminal perichondrium or transforming growth factor (TGF) beta3 influences the presence of MMP-2 and/or -9 within the chondrocytes of the cricoid cartilage.


METHODS
Subglottises from 15 neonatal mice were divided into group A (N = 5; luminal epithelium intact, grown in basic medium), group B (N = 5; epithelium-free, with sections of luminal perichondrium removed, grown in basic medium), and group C (N = 5; epithelium-free, with sections of luminal perichondrium removed, grown in basic medium with supplemental TGF-beta3). Immunohistochemical analysis was done to identify MMP-2 and -9 distributions.


RESULTS
Group A demonstrated concentrations of MMP-2 and -9 in the luminal perichondrial and adjacent chondrocytes with a gradual decrease in signal intensity toward the outer perichondrium. Group B showed findings similar to those in group A, but in the region of removed perichondrium, the adjacent chondrocytes lost MMP-2 and -9 signal. The group C rings demonstrated reestablishment of MMP-2 and -9 signal in regions of luminal perichondrial loss.


CONCLUSIONS
Localization of MMP-2 and -9 is predominantly in the luminal perichondrium and gradually decreases toward the outer perichondrium. The luminal perichondrium maintains expression of MMP-2 and -9 within the adjacent chondrocytes. Exogenous TGF-beta3 reestablishes production of at least MMP-9, and probably MMP-2, in cricoid cartilages missing luminal perichondrium.
Martinez-Alvernia
Efrain A
EA
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, Massachusetts, USA.
Mankarious
Leila A
LA
D000818:Animals; D000831:Animals, Newborn; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism; D003238:Connective Tissue / Q000378:metabolism* / Q000601:surgery; D003413:Cricoid Cartilage / Q000166:cytology / Q000378:metabolism* / Q000601:surgery; D007150:Immunohistochemistry; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051379:Mice; D053782:Transforming Growth Factor beta3 / Q000494:pharmacology*
D053782:Transforming Growth Factor beta3; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9