Abstract
Purpose :
Currently, anti-vascular endothelial growth factor (VEGF) therapy is the first line treatment for neovascular age-related macular degeneration (nAMD). However, a substantial number of patients are not responsive to the treatment or may develop resistance over time. Furthermore, subretinal fibrosis can develop in approximately 50% of patients after two years of anti-VEGF treatment. Epithelial-mesenchymal transition (EMT) in retinal pigment epithelial cells (RPECs) was reported to play a key role in subretinal fibrosis associated with nAMD. In this study, we aim to investigate the impact of a novel lipase, SIPRAD007, on RPEC function.
Methods :
Trypan blue exclusion and Ki-67 proliferation assays were performed to study the role of SIPRAD007 on the viability and proliferation of immortalised human RPECs, ARPE-19. The effect of SIPRAD007 on TGFβ1-induced expression of cytostatic and fibrotic genes was studied by real-time quantitative polymerase chain reaction (RT-qPCR) and/or Western blot analysis.
Results :
Our study showed a significant reduction in the viability and proliferation of SIPRAD007 siRNA transfected ARPE-19 cells as compared to scrambled siRNA-treated control cells by 14.2 ± 2.7% (n=4) and 46.3 ± 12.9% (n=3) respectively. This observation was supported by an increased expression of cell cycle inhibitors, p15 and p21, in SIPRAD007 knockdown ARPE-19 cells. Furthermore, the siSIPRAD007-treated ARPE-19 cells were more responsive to TGFβ1-induced expression of connective tissue growth factor (CTGF) and plasminogen activator inhibitor-1 (PAI-1).
Conclusions :
Our results demonstrated an important role of SIPRAD007 in RPEC viability, proliferation and the expression of fibrotic markers, including PAI-1 and CTGF.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.