Time-dependent Glucocorticoid-Induced Transcriptomic Changes in Human Trabecular Meshwork and Schlemm's Canal

PurposeTo identify the transcriptomic changes induced by dexamethasone (DEX) in trabecular meshwork (TM) and Schlemms canal endothelial (SCE) cells with RNA-sequencing (RNA-seq). MethodsHuman TM (n=10) and SCE cell strains (n=5) were isolated from healthy donor eyes and exposed to DEX 100nM and vehicle (control). Three DEX exposure times were evaluated: 1-hour, 6-hours, and 2 days. RNA-seq was performed on Illuminas TruSeq platform and gene expression was quantified using featureCount. DESeq2 paired (treated and untreated) sample test was applied to identify genes transcriptionally responsive to DEX (DEGs) at false discovery rate <0.05. Gene-set enrichment analyses were performed on DEGs. DEGs were tested for association with glaucoma (POAG) and intraocular pressure (IOP). ResultsNine TM and 4 SCE strains passed quality control. After 2-day DEX exposure, there were 857 and 2,086 DEGs in TM and SCE, respectively. Of these, 411 genes were differentially expressed in both TM and SCE, including FKBP5 (17.3-fold-change, p=6.9x10-53) and FAM107A (25.1-fold-change, p=4.0x10-240), the most significant DEG after 2-day DEX exposure in TM and SCE, respectively. The 2-day DEX DEGs in TM and SCE were enriched in cell adhesion, extracellular matrix, and response to stimulus in Gene Ontologies (p<3.7x10-6). Early response DEGs were enriched in immune-related processes. Thirteen DEGs in TM were significant at all three time points, including PER1. LTBP2 is a TM-only DEG and FAM105A a SCE-only DEG associated with IOP and POAG risk. ConclusionsThis study identified candidate genes and pathways for glucocorticoid-induced ocular hypertension which can be further explored in human genetic analyses.