Characterization of cellular inflammatory component in a mice choroidal neovascularization model

TOVO, A; SUBIRADA PV; VAGLIENTI MV; LUNA, JD; SANCHEZ, MC; CHIABRANDO, GA; BARCELONA, PF

Buenos Aires

Encuentro; Primer Encuentro Del Club de la Glía Cono Sur 19 al 21 de Octubre de 2022.; 2022

Club de la Glía

Argentina. Age-related macular degeneration (AMD) in its Choroidal Neovascularization (CNV) stage, where growing neovessels invade the retina inducing photoreceptor degeneration, is the leading cause of vision loss among adults. Mononuclear phagocytic cells (MPCs), such as resident microglia and monocyte-derived macrophages, collaborate in establish a chronic inflammatory state, which can lead to the onset of CNV. Our lab has previously demonstrated that multi-ligand Low density lipoprotein receptor-related protein 1 (LRP1), is expressed by MPCs in choroid from mice with CNV. In the present study, we aim to evaluate LRP1 expression and localization in retinal tissue during CNV in an animal model. C57BL/6 adult mice were treated with four spots of argon green laser photocoagulation per eye. At 1, 4, 7, 14 and 21 days after laser, they were sacrificed and retinal tissue was processed by WB to study LRP1 protein expression. It has been established that the model show the highest levels of cell infiltration at 4 days after laser, so at this time point we evaluated LRP1 transcript levels by rtPCR, its expression on resident MPCs by FACS assay and its localization in retinal cryosections by Immunofluorescence. We could observed that LRP1 protein expression increases from day 1 to 21. Particularly at 4 days after laser, we found a higher number of MPCs expressing LRP1. However, receptor transcript levels do not show changes. By IF it is possible to observe the activation of both, Muller and microglial cells, together with changes in LRP1 expression close to CNV area at inner nuclear layer. These results lead us to conclude that retinal expression of LRP1 might be involved in the inflammatory process during CNV. What is more, MPCs number could be responsible of this effect. Further studies are needed to know the role of LRP1 on the inflammatory component.