Single cell genomics of macular retina and RPE/choroid in intermediate Age-related Macular Degeneration

Abstract

Purpose : The goal of the study is to identify molecular mechanisms underlying Age-related Macular Degeneration (AMD). AMD is a leading cause of visual impairment in developed countries. While anti-VEGF treatments are effective for neovascular AMD, there remains a large unmet need for therapeutics of dry forms of AMD. Inhibitors of C3/ C5 complements were recently approved for Geographic Atrophy, though the efficacy of these treatments are still limited. For intermediate AMD, which affects ~185M patients worldwide, there are no treatment options beyond AREDS2 supplements. While emerging genomic studies of AMD ocular tissues are beginning to shed light on molecular changes in disease, a comprehensive single cell atlas of the AMD macula, with detailed phenotypic assessment allowing for disease-related pathways, is still lacking. Here we present our progress on generating large single cell genomic comparisons of normal and intermediate AMD macular tissues (iAMD) phenotyped by multi-modal post-mortem imaging

Methods : Macular retina and RPE-choroid tissues from the same eye were obtained from age-matched rapidly autopsied eyes, (<6 hours) which were subject to post-mortem phenotyping, as detailed in Utah protocol (PMID: 30924847). Microscopic dissection was used to isolate the macular retina from underlying RPE-choroid. Nuclei were isolated from the cryopreserved tissues (retina and RPE/choroid) and processed using 10x multiomics or 10X 3’ v3.1 kit respectively to generate gene expression and chromatin accessibility data from the same nuclei

Results : In this study, we generated gene expression data from the macular retinas and macular RPE/choroid from a cohort of control and iAMD donors. We profiled an average of ~10k nuclei per donor and the major cell types of the ocular tissues were well represented across all donors. As expected, we did not see any global shifts in gene expression and chromatin accessibility when we compared the control and iAMD tissues. Pseudobulk differential analysis were used to explore molecular pathways in intermediate AMD.

Conclusions : This is the first comparative single cell analysis of rapidly autopsied and deeply phenotyped macular tissues from human iAMD. This study provides valuable insights into the molecular basis of AMD pathophysiology, and offers a benchmark for emerging in vivo and in vitro disease models of AMD.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.