Single cell atlas of the human trabecular meshwork and ciliary body

The trabecular meshwork (TM) and ciliary body (CB) play critical roles in regulating vitreous homeostasis in the human eye. The TM serves as the primary outflow pathway for aqueous humor, while the CB controls lens shape and produces aqueous humor. Both tissues are composed of diverse cell types, with cell abundances varying across several orders of magnitude. To create a comprehensive single-cell atlas and advance our understanding of TM and CB biology, we generated large-scale datasets from healthy human donors using single-nucleus RNA-seq (snRNA-seq), single-cell RNA-seq (scRNA-seq), and single-nucleus ATAC-seq (snATAC-seq) across a range of ages, genders, and ethnic backgrounds. Additionally, we performed a meta-analysis by integrating previously published datasets. All data were uniformly preprocessed and combined, resulting in a comprehensive TM and CB atlas that includes transcriptomic profiles of over 1 million cells from 70 donors. We identified 19 distinct cell types, including rare populations such as immune cells, with the least abundant types representing as little as 0.08% of the total cell population. Furthermore, snATAC-seq profiling of over 500,000 nuclei provided detailed chromatin accessibility landscapes, allowing for the identification of cis-regulatory elements specific to each cell type. All datasets are publicly accessible via CELLxGENE and the UCSC Cell Browser, enabling interactive exploration of gene expression and chromatin states at the single-cell level. As part of the Human Cell Atlas initiative, our TM and CB atlas offers a valuable resource for understanding eye physiology and establishes a foundation for further research into the cellular and molecular mechanisms regulating intraocular pressure and related ocular diseases.