Transcriptome changes driving multiple regulatory pathways involved in TGF-β-induced Anterior Subcapsular Cataract

Transforming Growth Factor-beta (TGF-β) promotes lens epithelial-mesenchymal tran-sition (EMT) and fibrosis, contributing to anterior subcapsular cataract (ASC) formation. Transgenic mice overexpressing TGF-β1 in lens have been studied for over three decades, and yet the impact of active TGF-β1-overexpression on the lens epithelial transcriptome is undefined. We have addressed this knowledge gap by examining the gene expression landscape of these unique lens epithelia. High-throughput RNA-sequencing was per-formed on isolated lens epithelia from three-week-old TGF-β1-overexpression trans-genic mice from two independent lines, OVE853 and OVE918, and wild-type mice. Downstream analyses included comparisons with lens datasets (e.g., cataract-surgery model) and investigations using various resources/tools (e.g., Gene Ontology, CompBio, iSyTE). Compared to wild-type murine lens epithelia, 384 differentially expressed genes (DEGs) were commonly identified in lens of both transgenic lines. Candidates involved in EMT, inflammatory response, extracellular matrix organization, and mecha-no-sensation were elevated, while those involved in lipid metabolism, Wnt-suppression, Bmp- and Notch-activation were reduced. Comparative analyses with temporal tran-scriptomes on a mouse cataract-surgery model identified overlapping pathological pathways, and some elevated genes, for example endoplasmic reticulum stress genes, were in agreement with human ASC data. A major discovery was the identification of several novel TGF-β1-targets. All our data is made user-friendly accessible through iSyTE.