Background and objectives: Matrix metalloproteinases (MMPs) and their physiological inhibitors, the tissue inhibitors of metalloproteinases (TIMPs) play significant roles in wound repair. The aim of this study was to determine whether MMP and TIMP-1 mRNA is differentially expressed between laser-created and excisional skin wounds.
Study design/materials and methods: Full-thickness wounds were created on the dorsal surface of Balb/c mice by either excision of the skin or with a CO2 laser. Animals were sacrificed at days 1, 3, 5, 7, 10, and 13, and their wounds processed for RNA isolation or histology and immunohistochemistry.
Results: Northern hybridization for MMP-3, -10, -13, and TIMP-1 mRNA demonstrated higher expression on days 1, 3, and 5 in the laser wounds as compared to the excisional wounds. Histological evaluation revealed a two day delay in the resurfacing of laser wounds as compared to excisional wounds. Immunohistochemistry of Day 5 and 7 excisional and laser wounds showed MMP-3 within the epidermal compartment and the neo-dermis. No remarkable differences were noted in the spatial distribution patterns of MMP-3 between wound types.
Conclusions: Our findings demonstrate that MMPs and TIMP-1 mRNA expression is higher on days 1-5 post injury in full thickness laser-created wounds than in comparable same day excisional wounds.
Copyright 2002 Wiley-Liss, Inc.