GSE67898
Reversal of persistent wound-induced retinal pigmented epithelial-to-mesenchymal transition by the TGFb pathway inhibitor, A-83-01.
Age-related macular degeneration (AMD) is a leading cause of blindness. Most vision loss occurs following the transition from a disease of deposit formation and inflammation to a disease of neovascular fibrosis and/or cell death. Here, we investigate how repeated wound stimulus leads to seminal changes in gene expression and the onset of a perpetual state of stimulus-independent wound response in retinal pigmented epithelial (RPE) cells, a cell-type central to the etiology of AMD. Using a human fetal RPE cell culture model that considers monolayer disruption and subconfluent culture as a proxy for wound stimulus, we have shown that prolonged wound stimulus leads to terminal acquisition of a mesenchymal phenotype post-confluence and altered expression of more than 40% of the transcriptome (see GEO:GSE62224). In contrast, at subconfluence fewer than 5% of expressed transcripts have 2-fold or greater expression differences after repeated passage. Protein-protein and pathway interaction analysis of the genes with passage-dependent expression levels in subconfluent cultures reveals a 158-node interactome comprised of two interconnected modules with functions pertaining to wound response and cell division.  Among the wound response genes are the TGFb pathway activators: TGFB1, TGFB2, INHBA, INHBB, GDF6, CTGF, and THBS1. Significantly, inhibition of TGFBR1/ACVR1B mediated signaling using receptor kinase inhibitors both forestalls and reverses the passage-dependent loss of epithelial potential. In this RNA-Seq based transcriptome analysis we show that the TGFb receptor kinase inhibitor, A-83-01, largely reverses the effects of passage and restores the transcriptome profile of Passage 4 RPE highly similar to that seen in differentiated Passage 0 RPE. Overall design: Examination of mRNA expression in three different primary fetal RPE donor lines in 32 day old  passage 0, passage 3, and passage 3 treated with 500 nM A-83-01 culutres