Background:
Matrix metalloproteinases (mmps) contribute to matrix remodelling in venous leg ulcers. extracellular mmp inducer (emmprin; cd147) has been reported to increase mmp expression, and membrane type 1 mmp (mt1-mmp) has been implicated in the activation of mmps.
Objectives:
To examine whether and to what degree emmprin, mmp-2, mt1-mmp and membrane type 2 mmp (mt2-mmp) are expressed in venous leg ulcers as well as the association with mmp activity.
Methods:
Emmprin, mmp-2, mt1-mmp and mt2-mmp were analysed by zymography and immunohistochemistry in biopsies from healthy skin and lesional tissue from venous leg ulcers.
Results:
Zymography provided direct evidence of increased proteolytic activity of mmp-2 in lesional skin in comparison with healthy controls. immunostaining showed intense expression of emmprin, mmp-2, mt1-mmp and mt2-mmp in dermal structures of venous leg ulcers, whereas only emmprin and mmp-2 showed elevated expression in perivascular regions. our findings indicate that venous leg ulcers are characterized by elevated expression of emmprin, mmp-2, mt1-mmp and mt2-mmp. the immunohistological findings of skin alterations reflect the dynamic process of activation of soluble and membrane-bound mmps, which may be highly induced by emmprin.
Conclusions:
These data suggest for the first time that membrane-bound mmps may favour enhanced turnover of the extracellular matrix and support unrestrained mmp activity in venous leg ulcers.