Expression of matrix metalloproteinases (MMP)-12 by myofibroblasts during alkali-burned corneal wound healing.
OBJECTIVE
The purpose of this study was to determine the expression of MMP-12 by myofibroblasts during the healing of alkali-burned rabbit corneas (ARC), thus implicating its role in ECM remodeling.


METHODS
Rabbit corneas during alkali burn were examined for MMP-12 mRNA expression by RT-PCR. Immunohistochemistry was used to determine the presence of alpha-SMA, MMP-12 protein, and macrophages. In situ hybridization was performed to identify MMP-12 mRNA expressing cells.


RESULTS
RT-PCR showed that MMP-12 mRNA was expressed in the alkali-burned corneas from one week after the injury. Immunohistochemistry showed myofibroblasts positive for MMP-12 expression. In situ hybridization revealed that MMP-12 mRNA was expressed by myofibroblasts.


CONCLUSIONS
Our results indicate that, in alkali-burned corneas, myofibroblasts express both MMP-12 mRNA and protein. We suggest that MMP-12 may disintegrate some components of the ECM released after severe alkali burn, which may be involved in the ECM remodeling.
Iwanami
Haruhi
H
Department of Ophthalmology, Nippon Medical School, Bunkyo-ku, Tokyo, Japan.
Ishizaki
Masamichi
M
Fukuda
Yuh
Y
Takahashi
Hiroshi
H
D000199:Actins / Q000378:metabolism; D000818:Animals; D002057:Burns, Chemical / Q000235:genetics* / Q000378:metabolism; D003315:Cornea / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005126:Eye Burns / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000201:enzymology*; D019084:Fluorescent Antibody Technique, Indirect; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008297:Male; D053508:Matrix Metalloproteinase 12 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012972:Sodium Hydroxide; D014945:Wound Healing / Q000502:physiology*
D000199:Actins; D012333:RNA, Messenger; D012972:Sodium Hydroxide; D053508:Matrix Metalloproteinase 12