MMP inhibitor (Ilomastat) / post operative ocular scarring
Invest Ophthalmol Vis Sci. 2003 Mar;44(3):1104-10.
Matrix metalloproteinase inhibition modulates fibroblast-mediated matrix contraction and collagen production in vitro.
Daniels JT, Cambrey AD, Occleston NL, Garrett Q, Tarnuzzer RW, Schultz GS, Khaw PT.
Wound Healing Research Unit, Department of Pathology and Glaucoma, Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom. j.daniels@ucl.ac.uk
PURPOSE: To investigate the effect of matrix metalloproteinase (MMP) inhibition on fibroblast-mediated matrix contraction and production. METHODS: Free-floating fibroblast-populated type I collagen lattices were prepared with human Tenon's capsule fibroblasts. Lattice areas were photographed and digitally analyzed to indicate the degree of lattice contraction. Quantitative competitive reverse transcription-polymerase chain reaction (QCRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to quantify mRNA and protein respectively for MMP-1, -2, and -3 by fibroblasts during lattice contraction. Gelatin zymography demonstrated activity of MMPs released into the conditioned medium of contracting lattices. Concentrations of the broad-spectrum MMP inhibitors ilomastat, CellTech (Slough, UK), and BB-94 were added to the contracting fibroblast-populated collagen lattices. Secreted C-terminal propeptide of type I collagen was measured in conditioned medium of contracting lattices by ELISA. Fibroblast proliferation in the presence of concentrations of ilomastat was measured by using the reagent water-soluble tetrazolium-1 (WST-1). RESULTS: During contraction of type I collagen lattices, Tenon's capsule fibroblasts expressed MMP-1, -2, and -3 mRNA and protein. Zymography demonstrated the release of four gelatinolytic species into the conditioned medium of contracting lattices (57, 72, 91, and 100 kDa). Inclusion of MMP inhibitors in the zymogram-developing buffer reduced the proteolytic activity of the detected bands. MMP inhibition (1-100 microM) significantly reduced fibroblast-mediated collagen lattice contraction (P < 0.05), and this effect was found to be reversible. Ilomastat also significantly inhibited production of collagen in a dose-dependent manner (P < 0.05). No effect on fibroblast proliferation was found in the presence of ilomastat. CONCLUSIONS: MMPs are produced during Tenon's capsule fibroblast-mediated collagen lattice contraction. Broad-spectrum MMP inhibition significantly reduced matrix contraction and production without cell toxicity. Future clinical use of MMP inhibitors may be possible, because MMP inhibition significantly reduces fibroblast functions associated with contractile scarring.
PMID: 12601036 [PubMed - indexed for MEDLINE]
rcophth.ac.uk
11.40 a.m. Modulation of matrix metalloproteinases controls fibroblast scarring activity and minimises ocular scarring following experimental surgery
T. T. L. Wong, J. T. Daniels, A. L. Mead, G. Murphy, P. T. Khaw
Institute of Ophthalmology, London
Purpose: Matrix metalloproteinases (MMPs) are important modulators of wound healing. Excessive post-operative scarring following glaucoma surgery leads to poor intraocular pressure control and disease progression. We investigated the effect of MMP modulation on fibroblast activity both in vitro and in vivo.
Methods: The effect of MMP inhibition on human Tenon's fibroblast-mediated collagen gel contraction was determined in vitro. Gel contraction was measured, MMP activity, protein and mRNA expression were analysed. Using an experimental model of filtration surgery, the effect of subconjunctival injections of Ilomastat on post-operative scarring was determined and compared to Mitomycin-C. Clinical signs of scarring were recorded and the tissue was histologically analysed.
Results: Inhibiting MMP activity reduced collagen gel contraction (p<0.001). MMP activity and expression were dose-dependently reduced by Ilomastat. Surgical outcome was significantly improved with Ilomastat (Log Rank p=0.001) compared to vehicle control. A reduction in scar tissue formation was observed (p<0.01). Treatment with Ilomastat resulted in bleb survival comparable to the MMC-treated animals (Log Rank p=0.0163). Intraocular pressure (IOP) remained low postoperatively with both Ilomastat and MMC compared to vehicle (Log rank p=0.033).
Conclusions: Modulation of MMPs inhibits fibroblast-mediated scarring activity. MMP inhibition successfully maintained low post-operative IOP and significantly improved surgical outcome similar to MMC. However, unlike antimetabolite treatment, the conjunctival tissue retained normal morphology and extensive cell death was not seen. By targeting these enzymes, a more controlled and physiological method of modulating scarring may be achieved and prove useful in the prevention of scarring in other parts of the eye and human body. |
