Effects of fibroblastic and endothelial extracellular matrices on corneal endothelial cells

Extracellular matrices (ECM) isolated from chick embryo fibroblast and human and rabbit corneal stromal cells induce polarization and elongation of corneal endothelial cells in culture. ECM isolated from rabbit corneal or bovine aortic endothelial cells neither polarize nor elongate corneal endothelial cells in culture. By indirect immunofluorescence, fibronectin is seen as arrays of long fibers in fibroblastic ECM, whereas in endothelial ECM, fibronectin is found in discreet foci as short fibers. The morphology corneal endothelial cells in culture is associated with the structure of the ECM laid down; short fibers in clusters associated with a typical polygonal shape, long polarized fibers inducing a fibroblastic-like appearance. ECM isolated from both fibroblastic or endothelial sources promote cell growth. Since coating the plastic with plasma fibronectin or denatured collagen does not promote endothelial cell growth, the authors assume the polymerized fibronectin network or a component bound to this network enhances the growth of corneal endothelial cells cultured in the presence of serum.