Differential expression of MT1-MMP (MMP-14) and collagenase III (MMP-13) genes in normal and wounded rat corneas.
OBJECTIVE
Several members of the matrix metalloproteinase (MMP) group have been identified in the rat cornea during corneal wound healing. The aim of the present study was to identify additional members of the MMP gene family in the rat cornea and localize the expression of membrane type-1 matrix metalloproteinase (MT1-MMP; MMP-14) and collagenase III (MMP-13) in normal and wounded corneas.


METHODS
Adult rats underwent laser keratectomy on the right eye. Unwounded left eyes were normal controls. Corneas were collected and processed at different times post-wounding. Reverse transcription-polymerase chain reaction (RT-PCR) and DNA sequencing were used to discover the MMP genes expressed in the corneas. In situ hybridization was performed to localize the mRNA expression of MMP-14 and MMP-13.


RESULTS
MMP-13 mRNA was detected in epithelial cells of wounded corneas, but not in normal controls; MMP-14 was found in both normal and wounded corneas. MMP-14 mRNA was expressed predominantly in the stromal keratocytes and rarely in the basal epithelial cells in normal and wounded corneas. MMP-13 mRNA was localized exclusively to basal cells of the epithelium at the wounded area from 6 hours to 3 days after wounding.


CONCLUSIONS
MMP-14 and MMP-13 expression in rat corneas parallels that of gelatinases A and B, respectively. MMP-13 may play an important role in the gelatinase B-associated proteolytic cascade that allows rapid turnover of the extracellular matrix (ECM) components during corneal wound healing. MMP-14 may contribute to removing abnormal ECM components through activation of gelatinase A in rat corneas.
Ye
H Q
HQ
Schepens Eye Research Institute and the. Massachusetts Eye and Ear Infirmary Department of Ophthalmology, Harvard Medical School, Boston 02114, USA.
Maeda
M
M
Yu
F S
FS
Azar
D T
DT
D000818:Animals; D017364:Collagenases / Q000096:biosynthesis / Q000235:genetics*; D003315:Cornea / Q000201:enzymology*; D065306:Corneal Injuries; D003319:Corneal Stroma / Q000201:enzymology; D019573:Epithelium, Corneal / Q000201:enzymology; D005131:Eye Injuries / Q000201:enzymology*; D015870:Gene Expression; D017403:In Situ Hybridization; D007834:Lasers; D053508:Matrix Metalloproteinase 12; D053509:Matrix Metalloproteinase 13; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000235:genetics*; D015347:RNA Probes / Q000737:chemistry; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014945:Wound Healing
D015347:RNA Probes; D012333:RNA, Messenger; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C507083:Mmp13 protein, rat; D053508:Matrix Metalloproteinase 12