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

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.

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.

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.

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.