Purchase this article with an account.
B.M. Martin, P.T. Khaw, M. Bailly; Effect of MMP Inhibitor Ilomastat on Tissue Contraction Mediated by Different Fibroblasts . Invest. Ophthalmol. Vis. Sci. 2006;47(13):2621.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Broad spectrum MMP inhibitor Ilomastast has proven efficient in preventing ocular tissue scarring after experimental glaucoma filtration surgery. The purpose of this study is to characterise its biological mode of action in a standard in vitro contraction.
Free–floating fibroblast–populated type I collagen matrices were prepared with Scleral, Tenon's capsule and NIH3T3 fibroblasts. Gel contraction induced with foetal calf serum in presence or absence of Ilomastat was monitored macroscopically using digital photography. The biological behaviour of the cells and their interaction with the collagen matrix was analysed using confocal reflection microscopy. OpenLab and Volocity software packages were used to analyse the 3 and 4D reconstructed image series. Cell division and matrix metalloproteinase activity were measured by cell counts and fluorimetric assay respectively.
While similar end point contraction (70–90% of original volume) was obtained by varying the number of cells in the gels, the different types of fibroblasts display distinct behaviour and interaction with the matrix during contraction. The Tenon's did not divide in the matrix but efficiently pulled collagen fibers. Scleral cells divided significantly over 7 days, but were poorly efficient in pulling matrix fibers, while 3T3 cell displayed moderate behaviour for both cell division and matrix displacement. Conversely, collagen degradation around the cells was more pronounced with the scleral fibroblasts. The inhibitory effect of Ilomastat on contraction was more pronounced on Tenon's fibroblasts than 3T3 or scleral fibroblasts, despite Ilomastat clearly inhibiting on cell division in the latter ones. Ilomastat decreased the MMP activity released in the gels after serum stimulation of scleral cells, but increased membrane–bound MMP activity over 7 days.
We propose that different types of cell use different behavioural combinations to achieve matrix contraction. Tenon's fibroblasts are extremely efficient at pulling collagen fibers, resulting in active contracting force. Scleral fibroblasts are poorly efficient at pulling the matrix but can increase their overall contracting force through cell division. These cells are poorly inhibited in their contraction ability by Ilomastat, despite the MMP inhibitor significantly blocking cell division and soluble MMP production. Our data suggest that successful modulation of tissue scarring in the eye by MMP inhibitors will depend on the type of tissue affected.
This PDF is available to Subscribers Only