Abstract
Purpose :
The role of ROCK1 and ROCK2(two isoforms of Rho-kinase) in the development of proliferative vitreoretinopathy (PVR) is unknown. The purpose of this study was to establish a mouse model of PVR, study rho kinase expression during PVR and investigate the effect of Rho-kinase inhibitors fasudil (a pan-ROCK inhibitor) and belumosudil (a specific ROCK2 inhibitor) on PVR development.
Methods :
We established a PVR mouse (C57BL/6 mouse, mixed sex, 8-9 weeks, n=6 per group) model by intravitreal injection of ARPE-19 cells (ATCC, CRL-2302; 0.8 X 104 cells). From day 21 to 35 after PVR induction, treatment involved daily intraperitoneal administration of fasudil and twice-daily injections of belosumodil. Optical coherence tomography (OCT) was performed on 7, 14, 21, 28 and 35 days following the successful modelling. Eyes were used at each time point for paraffin sectioning (H&E,immunohistochemistry) and tissue harvesting for western blots. We also compared fibrosis-related, apoptosis-related, and angiogenesis-related antibody expressions in normal and PVR mouse retinas using Imaging Mass Cytometry (IMC).
Results :
A PVR mouse model was successfully established which resembles the human condition with formation of preretinal fibrosis and retinal detachment. Over time, PVR formation became more severe in the vehicle treated group. At 21 days, retinal detachment, a serious complication of PVR, was observed in some of the mice eyes. However, 14 days of ROCK inhibitor treatment led to a reduction of mouse PVR. Post-treatment, immunohistochemical analysis revealed a significant decrease in ROCK1,ROCK2 and fibrotic marker expression, confirmed in western blot and IMC analyses.
Conclusions :
Treatment with fasudil and belumosudil reduces PVR severity in mice and alters the expression of fibrotic markers related to the condition.For the first time, employing IMC technology, we have identified cell types on mouse retina, and distinct differences in marker expression between normal mouse retinas and those with PVR.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.