Abstract
Purpose :
Previous studies have shown that Pigment-Epithelium-Derived-Factor (PEDF) and its derived shorter peptides can stimulate the growth of limbal stem cells. Additionally, PEDF-derived shorter peptides (PDSP) have a regulatory role in healing corneal wounds in vivo models. This study aims to investigate the effect of PDSP on the regulation of cell proliferation and wound healing in retinal or corneal epithelial cells.
Methods :
Cell viability was studied by crystal violet cell viability/proliferation assay on rat retinal cell line R28 (n=3~4 independent experiments). Effects on PDSP-induced cell proliferation and migration were investigated by an in vitro scratch-wound model using both retinal cell line R28 (n=3~4 independent experiments) and human corneal epithelial cells (hCECs; n=5 independent experiments)
Results :
As shown in Figure 1, the PDSP treatment increased R28 cell growth in a dose-dependent manner, peaking at 1x10^-7M (p=0.0044 for 10^-16 vs 10^-7 M; p=0.0168 for 10^-15 vs 10^-7 M; p=0.0105 for 10^-14 vs 10^-7 M). The wound healing assay depicted in Figure 2a & c indicates that R28 cells and hCECs treated with PDSP repaired the scratch area much faster than the untreated cells. We observed a significant increase in the number of migrating cells in the presence of PDSP at 18 and 36 hours after creating the scratch, compared to the untreated R28 cells. This effect was most prominent at the concentration of 8 nM (18hr: 0 vs 8nM, p=0.0135; 36hr: 0 vs 6 nM, p=0.0363; 0 vs 8nM, p=0.0206). Additionally, the treatment with PDSP significantly increased wound closure in hCECs (P<0.05). This was especially evident at the concentration of 10 nM and 15 nM (18hr: 0 vs 10nM, p=0.0496; 0 vs 15nM, p=0.0234; 24hr: 0 vs 10nM, p=0.0231; 0 vs 15nM, p=0.0194).
Conclusions :
Treatment of PDSP, a PEDF-derived short peptide, can promote retinal and corneal epithelial cell proliferation and migration. Upon increasing the concentration, we observed a decrease in response. Further investigation is required to determine if this is due to the PEDF receptor internalization caused by the high concentration of PDSP treatment, which leads to a loss of efficacy
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.