Interaction of retinal glial cells with collagen matrices: implications for pathogenesis of cell-mediated vitreous traction.

Traction retinal detachment results in severe visual loss in many proliferative vitreoretinal disorders. Retinal glial cells participate in nearly all of the proliferative diseases involving the retina. In order to better understand the mechanism of vitreous traction we used phase-contrast and scanning electron microscopy to study the interaction of human retinal glial cells and rabbit dermal fibroblasts with collagen gels. To modify this interaction, we placed a peptide containing the arginine-glycine-aspartic acid sequence that competes for the cellular binding site of fibronectin onto the collagen gels. We found that both glial cells and fibroblasts attached to collagen fibers and pulled them centripetally. The cells extended their processes toward adjacent cells in the gel creating "strands" and traction in a self-promoting fashion. Despite a dramatic effect on fibroblast-mediated traction, the peptide had little effect on glial cells even at 3 mg/ml.