Human corneal epithelial cells require MMP-1 for HGF-mediated migration on collagen I.
OBJECTIVE
To investigate the potential regulation of matrix metalloproteinases (MMPs) by hepatocyte growth factor (HGF), and to identify individual MMPs essential for migration of human corneal epithelial cells.


METHODS
Migration of human corneal epithelial cells (HCECs) was measured with a colony dispersion assay in response to concentrations of HGF (0-50 ng/mL). MMP activity in the conditioned media collected from the dispersion assay was assessed by zymography. The broad-spectrum MMP inhibitor ilomastat (1-100 microM) or an MMP-9-neutralizing antibody (1-10 microg/mL) were included in the dispersion assay to determine their effects on HCEC migration. Immunocytochemistry and in situ hybridization were used to localize MMP-1 in HCECs in the colony dispersion assay and in a human ex vivo corneal wound-healing model, respectively. ELISA for MMP-1 was performed on conditioned medium from migrating HCECs. Neutralizing antibodies to MMP-1 and -9 were added to an in vitro scratch-wound model to assess the effect on HCEC healing.


RESULTS
HCEC migration (P < 0.05) and MMP-2 and -9 released into the medium increased in response to HGF in a dose-dependent manner up to 20 ng/mL. Broad-spectrum MMP inhibition significantly reduced HCEC migration (P < 0.05). In contrast, neutralization of MMP-9 increased migration (P < 0.05). MMP-1 was found in association with HCECs at the migratory leading edge in both the dispersion and the ex vivo wound-healing experiments, and was found to be stimulated above basal levels by HGF. Neutralization of MMP-1 significantly decreased (P < 0.05), whereas neutralization of MMP-9 significantly increased (P < 0.05), scratch-wound closure.


CONCLUSIONS
This study provided novel data regarding HCEC migration in response to HGF and highlighted the importance of MMPs, particularly MMP-1 in migration and possibly reepithelialization in vivo. MMP-9 and/or -2 may be released by HCECs to remodel matrix behind the leading migratory front. Studies such as this are essential to assist in the safe and efficacious design of MMP inhibitors for therapeutic use in the eye.
Daniels
Julie T
JT
Epithelial Repair and Regeneration Group, Wound Healing Research Unit, Division of Pathology, Institute of Ophthalmology, London, United Kingdom. j.daniels@ucl.ac.uk
Limb
G Astrid
GA
Saarialho-Kere
Ulpu
U
Murphy
Gillian
G
Khaw
Peng T
PT
D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000201:enzymology; D019573:Epithelium, Corneal / Q000166:cytology* / Q000201:enzymology*; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D006877:Hydroxamic Acids; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D007211:Indoles / Q000494:pharmacology; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D014945:Wound Healing
D024042:Collagen Type I; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D007211:Indoles; D061965:Matrix Metalloproteinase Inhibitors; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor; D020781:Matrix Metalloproteinase 1; C119203:ilomastat