Disease transcriptomics and chromatin accessibility in intermediate AMD at single cell resolution

Abstract

Purpose : Age-related Macular Degeneration (AMD), a leading cause of blindness in developed countries, lacks curative therapies partly due to variable end-stage phenotypes. The non-exudative AMD phenotype, characterized by sub-retinal drusen formation and subsequent degeneration of macular retinal cells, leads to irreversible central vision loss. The goal of this study is to identify pathways underlying AMD progression from intermediate (iAMD) to advanced non-exudative disease (Geographic Atrophy). While several published transcriptomics studies include AMD ocular tissue both at bulk and single cell level, a comprehensive human molecular atlas of the AMD macula, with detailed phenotypic assessment allowing for disease-related transcriptomics, is still lacking. To address this knowledge gap and elucidate molecular drivers of AMD pathology, here we detail single cell multiomics datasets from age-matched normal and intermediate AMD macular tissues (iAMD) phenotyped by post-mortem imaging

Methods : Retinal tissues from rapidly autopsied (<6 hours) and rigorously post-mortem phenotyped eyes were analyzed, including 10 age-matched controls or AREDS3 iAMD eyes as published by our group using the Utah Protocol (PMID: 30924847). A 6 mm macular punch was isolated and retina were dissected from underlying RPE/choroid tissues using microscopic dissection. Nuclei were isolated and processed using 10x Genomics multiomics workflow to generate single NucSeq and ATACseq datasets.

Results : In this study, we profiled an average of 12-15k nuclei from each donor macular retina. We generated single cell gene expression and chromatin accessibility datasets from the same nuclei and characterized major cell types from control and iAMD tissues. Using this data, we examined changes in gene expression between control and AMD, and explored putative causal genes and regulatory regions in AMD GWAS loci. This study will be expanded to a larger cohort of donors to achieve a well-powered multiomics study of iAMD.

Conclusions : This is the first comparative single cell multiomics analysis of rapidly autopsied and deeply phenotyped macular tissues from human iAMD. This study provides valuable insight 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 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.