Modeling dry eye with an air-liquid interface in corneal epithelium-on-a-chip

Abstract

ABSTRACTDry eye syndrome (DES) is a complex ocular condition characterized by an unstable tear film and inadequate tear production, leading to tissue damage. Despite its common occurrence, there is currently no comprehensivein vitromodel that accurately reproduce the cellular characteristics of DES. Here we modified a corneal epithelium-on-a-chip (CEpOC) model to recapitulate DES by subjecting HCE-T human corneal epithelial cells to an air-liquid (AL) interface stimulus. We then assessed the effects of AL stimulation both in the presence and absence of diclofenac (DCF). Transcriptomic analysis revealed distinct gene expression changes in response to AL and AL_DCF, affecting pathways related to development, epithelial structure, inflammation, and extracellular matrix remodeling. Both treatments upregulatedPIEZO2, linked to corneal damage signaling, while downregulatingOCLN, involved in cell-cell junctions. They increased the expression of inflammatory genes (e.g.,IL6) and reduced mucin production genes (e.g.,MUC16), reflecting dry eye characteristics.TGFB1, crucial for corneal wound healing, was slightly downregulated in AL_DCF, potentially affecting wound healing processes rather than reducing inflammation by DCF. Metabolomic analysis showed increased secretion of metabolites associated with cell damage and inflammation (e.g., methyl-2-oxovaleric acid, 3-methyl-2-oxobutanoic acid, lauroyl-carnitine) in response to AL and even more with AL_DCF, indicating a shift in cellular metabolism. This study showcases the utilization of AL stimulus within the CEpOC as a comprehensive approach to faithfully reproduce the cellular characteristics of DES.