Abstract
Purpose :
RPE death is a hallmark of many ocular degenerative diseases such as age-related macular degeneration (AMD). However, the molecular pathways promoting RPE cell death during disease progression remain poorly understood. In this study, we have established screening assays to characterize pathways involved in RPE death and identify novel compounds able to prevent RPE death under disease mimicking conditions.
Methods :
A CytoTox-Glo cytotoxicity assay (Promega) was used as the primary screen measuring effects of compounds on preventing cell death induced by all-trans-retinal (atRAL, 18uM). 2,892 compounds with known targets (Novartis mechanism-of-action box) were evaluated and top hits were validated in a dose dependent study. Compound’s ability to prevent 4-hydroxy-2-nonenal (4-HNE)-induced cell death measured by propidium Iodide (PI) staining was assessed as secondary screening followed by hit validation on iPS-RPE (FUJIFILM Cellular Dynamics).
Results :
We identified 14 compounds able to prevent ARPE-19 cell death induced by both atRAL and 4-HNE (Figure 1A), including the AhR agonist 2-(4-Amino-3-methylphenyl) benzothiazole (DF 203, IC50=1.66 uM for atRAL, IC50=1.16 uM for 4-HNE). Another AhR agonist 5,11-Dihydroindolo[3,2-b] carbazole-6-carboxaldehyde (FICZ) also protected ARPE-19 from cell death induced by both atRAL (IC50=0.15 uM) and 4-HNE (IC50=0.027 uM, Figure 1B). Both DF 203 and FICZ showed strong protective effect against iPS-RPE death induced by 4-HNE (IC50=5.1 uM and IC50=0.62 uM, Figure 1C).
Conclusions :
Through a screen of 2,892 compounds, two AhR agonists were found to prevent toxin-induced cell death of ARPE-19 and iPS- RPE, indicating AhR agonism as a potential therapeutic approach for ocular diseases associated with RPE degeneration and death such as AMD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.