Effects of Verteporfin on Interstitial Fluid Flow-Induced Fibrotic Transdifferentiation of Human Tenon Fibroblasts.

PURPOSE: Postoperative scarring remains the major challenge in achieving long-term success after glaucoma filtration surgery. In a previous study, we showed that slow continuous fluid flow is sufficient to induce fibrotic responses in human tenon fibroblasts (HTFs) in two-dimensional (2D) and three-dimensional (3D) in vitro models. In the present study, we investigated the role of the mechanosensitive Yes-associated protein (YAP) and transcriptional coactivator (TAZ) signaling pathway in flow-induced fibrosis. METHODS: HTFs were exposed to continuous fluid flow for 48 or 72 hours in the presence or absence of the YAP/TAZ-transcriptional enhanced associated domain inhibitor verteporfin (VP). In a 2D model, the F-actin cytoskeleton, fibronectin 1 (FN1), YAP, and TAZ were visualized by confocal immunofluorescence microscopy. In a 3D model, mRNA was extracted, and the expression of fibrosis-associated genes was detected by quantitative PCR. RESULTS: HTFs exposed to slow fluid flow showed increased staining intensities for YAP/TAZ. Inhibition of YAP/TAZ by VP slightly reduced flow-induced fibrotic changes in the 2D model. The flow-induced increase in the expression of the extracellular matrix (ECM) genes COL1A1, CTGF, and FN1 was significantly inhibited by VP in the 3D model. CONCLUSIONS: Slow interstitial fluid flow activates the YAP/TAZ pathway. VP exerts antifibrotic potential by reducing morphologic changes and suppressing the expression of ECM genes induced by flow. Therefore, YAP/TAZ inhibition may exhibit therapeutic potential after glaucoma filtration surgery by inhibiting fibrotic changes induced by mechanical stimuli.