Epiretinal Amniotic Membrane Influences the Cellular Behavior of Profibrotic Dedifferentiated Cells of Proliferative Vitreoretinopathy In Vitro

Proliferative vitreoretinopathy (PVR) as a rare fibrotic ocular disease is the main reason for failure of retinal detachment surgery and a reduced prognosis following surgery. Amniotic membrane (AM) is a versatile surgical tool for tissue stabilization, antifibrotic properties, and regeneration. Initial clinical case studies now demonstrated intravitreal tolerance as well as good anatomical and functional results for degenerative retinal diseases. Due to its diverse wound healing properties, AM could have promoting, suppressive, or no effects on PVR. To illuminate the potential of epiretinal AM transplantation in complex retinal detachment cases, we investigated its influence on human primary PVR (hPVR) cells in vitro. In our cell culture study, hPVR cells were isolated from surgically removed PVR membranes. Following incubation with AM for 48 h, AM-incubated hPVR showed significantly reduced proliferation (BrdU-ELISA; $p<0.001$ ), migration (Boyden chamber, scratch assay; $p$ = 0.003 and $p<0.001$ ), and cell adhesion ( $p$ = 0.005). Collagen contraction was nearly unaffected ( $p$ = 0.04), and toxicity (histone-complexed DNA ELISA, WST-1 assay, and life/dead staining) was excluded. Next, immunofluorescence showed a myofibroblastic phenotype with reduced expression of fibrosis markers in AM-incubated cells, which was confirmed by Western blot analysis. In the proteomics assay, AM significantly regulated proteins by a more than 2-fold increase in expression which were related to the cytoskeleton, lipid metabolism, cell-matrix contraction, and protein folding. In conclusion, this in vitro work suggests no induction of fibrosis and other key steps in the pathogenesis of PVR through AM but rather inhibiting properties of profibrotic cell behavior, making it a possible candidate for suppression of PVR. Further clinical studies are necessary to evaluate the therapeutic relevance.