Abstract
Background: To identify which extracellular matrix components
modify retinal pigment epithelial cell migration and their interplay
with matrix metalloproteinases in directing the behaviour of the cells
in agarose droplets, an in-vitro model for cellular migration.
Methods: Migration of the cells from agarose droplets on coated
tissue culture plastic (fibronectin, laminin and collagen types: I and
IV) in the presence as well as absence of serum was evaluated by
using phase contrast microscopy and computer analysis of captured
images. Expression of metalloproteinases -1, 2 and 9 by retinal
pigment epithelial cells was determined by immunocytochemistry
and was confirmed by western blotting. In addition, the effect of
metalloproteinases inhibitor, batimastat (BB-94), on the cell
migration and expression of MMPs were studied.
Results: Retinal pigment epithelial cells migrated from agarose
droplets in the presence of serum and fibronectin acted as an
additional stimulus to migration, while laminin and collagen type IV
inhibited migration in a dose dependent manner. Metalloproteinases
-1, 2 and 9 were expressed by retinal pigment epithelial cells in
culture as shown by immunocytochemistry and by western blotting.
Expression of metalloproteinases on western blots was inhibited by
use of BB-94. BB-94, also inhibited cellular migration from agarose
droplets in a dose dependent manner.
Conclusions: Retinal pigment epithelial cells migrate in the
presence of fibronectin while expression of metalloproteinases
may reflect cellular behaviour during PVR in which migration
of cells from their basement membrane on to retinal surfaces
requires an interaction between ECM protein and enzymes such as
metalloproteinases to permit cellular invasion.