Abstract
Abstract: :
Purpose – Many investigators have found that injection of fibroblasts into the vitreous of a rabbit eye results in PVR. We have recently reported that this response is dependent on expression of the receptor for platelet-derived growth factor (PDGF). In addition the PDGF α receptor (α PDGFR) has a much higher PVR potential than the PDGF ß receptor (ßPDGFR). The goal of this study was to test the hypothesis that the α PDGFR was better than the ß PDGFR at causing PVR because the α PDGFR was better at promoting collagen synthesis. Methods – Collagen mRNA expression was determined by Northern blot analysis in immortalized mouse embryo fibroblasts that express the α PDGFR or the ß PDGFR or no PDGFRs. In addition, a panel of α PDGFR signaling mutants were tested for expression of collagen mRNA. Results – All cell types expressed readily detectable levels of collagen mRNA, which were not altered by stimulation with PDGF. The basal level of collagen mRNA was markedly enhanced by expression of the α PDGFR but not the ß PDGFR. Analysis of the αPDGFR signaling mutants indicated the c-Src was the signaling enzyme downstream of the αPDGFR that was most probably contributing to the elevation of collagen mRNA. Finally, comparison of the in vivo PVR potential and in vitro production of collagen mRNA revealed that there was no correlation between these two parameters. Conclusion – Expression of α PDGFR is sufficient to elevate collagen mRNA, but this does not appear to explain the enhanced ability of this receptor to drive PVR in the rabbit model of the disease.
Keywords: proliferative vitreoretinopathy • retinal detachment • retina