Molecular taxonomy of human ocular outflow tissues defined by single-cell transcriptomics.
The conventional outflow pathway is a complex tissue responsible for maintaining intraocular pressure (IOP) homeostasis. The coordinated effort of multiple cells with differing responsibilities ensures healthy outflow function and IOP maintenance. Dysfunction of one or more resident cell types results in ocular hypertension and risk for glaucoma, a leading cause of blindness. In this study, single-cell RNA sequencing was performed to generate a comprehensive cell atlas of human conventional outflow tissues. We obtained expression profiles of 17,757 genes from 8,758 cells from eight eyes of human donors representing the outflow cell transcriptome. Upon clustering analysis, 12 distinct cell types were identified, and region-specific expression of candidate genes was mapped in human tissues. Significantly, we identified two distinct expression patterns (myofibroblast- and fibroblast-like) from cells located in the trabecular meshwork (TM), the primary structural component of the conventional outflow pathway. We also located Schwann cell and macrophage signatures in the TM. The second primary component structure, Schlemm's canal, displayed a unique combination of lymphatic/blood vascular gene expression. Other expression clusters corresponded to cells from neighboring tissues, predominantly in the ciliary muscle/scleral spur, which together correspond to the uveoscleral outflow pathway. Importantly, the utility of our atlas was demonstrated by mapping glaucoma-relevant genes to outflow cell clusters. Our study provides a comprehensive molecular and cellular classification of conventional and unconventional outflow pathway structures responsible for IOP homeostasis.
['Patel|Gaurang|G|0000-0003-2497-665X', 'Fury|Wen|W|', 'Yang|Hua|H|', 'Gomez-Caraballo|Maria|M|', 'Bai|Yu|Y|', 'Yang|Tao|T|', 'Adler|Christina|C|', 'Wei|Yi|Y|', 'Ni|Min|M|', 'Schmitt|Heather|H|0000-0003-2007-7542', 'Hu|Ying|Y|', 'Yancopoulos|George|G|', 'Stamer|W Daniel|WD|', 'Romano|Carmelo|C|0000-0003-1138-4241']
D001082:Aqueous Humor D005901:Glaucoma D006801:Humans D007429:Intraocular Pressure D008264:Macrophages D058628:Myofibroblasts D000081246:RNA-Seq D012583:Schwann Cells D059010:Single-Cell Analysis D014129:Trabecular Meshwork
single-cell transcriptomics glaucoma trabecular meshwork anterior chamber outflow facility