Abstract
Purpose :
Proliferative vitreoretinopathy (PVR) is a complex vision threatening condition that can is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both the inner and outer side of retina. PVR pathogenesis is driven by retinal tears and inflammatory mediators within the vitreous. Currently, surgery is the only option available to cure PVR as there is no proven pharmacologic agent. The purpose of this study was to characterize the role of the aryl hydrocarbon receptor (AhR) in the pathogenesis of PVR. The AHR is a ligand activated transcription factor that bind to numerous natural and environmental ligands. Intriguingly, prior work suggests a role for the AhR in proliferation, metabolism, inflammation, and the immune response. However, the involvement of AhR in PVR remains unclear.
Methods :
ARPE-19 cells (ATCC, Manassas, VA) and primary RPE cells were grown in Dulbecco’s Modified Eagle’s Medium (DMEM) and Ham’s F12 media supplemented with 10% fetal bovine serum. Cells were treated with the proinflammatory cytokine, TNFα as well as AhR agonists. To confirm the role of AhR, control siRNA and AHR siRNA were introduced using RNA iMAX. Expression of inflammatory and fibrotic markers were measured by qPCR or Western Blotting.
Results :
TNFα, a proinflammatory cytokine, is elevated in the vitreous of PVR patients and regulates many functions of RPE cells. We found that ligand mediated cytoplasmic retention of the AhR attenuates the inflammatory effects of TNFα. Specifically AhR cytoplasmic retention reduces the production of inflammatory cytokines such as IL-6 and MCP-1. We also found that AhR represses TNFα induced expression of Snail, a master regulator of EMT and extracellular matrix proteins, fibronectin and collagen I.
Conclusions :
Our results indicate that TNFα induces nuclear transport of AhR and blocking AhR nuclear transport with a selective AhR ligand attenuated inflammation and EMT. These studies illuminate new insights into the role of the AhR in the pathogenesis of PVR and targeting the AhR in PVR may serve as a potential therapeutic option.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.