Induction by Latanoprost of Collagen Gel Contraction Mediated by Human Tenon Fibroblasts: Role of Intracellular Signaling Molecules

Abstract

The outcome of glaucoma filtration surgery is affected by subconjunctival wound healing. The effects of the antiglaucoma drug latanoprost on the contractility of human Tenon fibroblasts (HTFs) cultured in a three-dimensional collagen gel were investigated. HTFs were cultured in a type I collagen gel with latanoprost or various inhibitors of intracellular signaling. Collagen gel contraction was evaluated by measurement of gel diameter, and collagen degradation was determined by measurement of the amount of hydroxyproline generated by acid-heat hydrolysis of culture supernatants. Phosphorylation of mitogen-activated protein kinases (MAPKs), focal adhesion kinase (FAK), and myosin light chain (MLC) was assessed by immunoblot analysis, and the formation of actin stress fibers was examined by laser confocal microscopy. HTF-mediated collagen gel contraction was stimulated by latanoprost in a concentration- and time-dependent manner. Latanoprost had no effect on collagen degradation by HTFs. Latanoprost induced phosphorylation of MAPKs (ERK, p38, and JNK) and FAK, as well as the formation of stress fibers in HTFs. Furthermore, latanoprost-induced collagen gel contraction was reduced by inhibitors of ERK (PD98059 and ERK inhibitor II), p38 (SB203580), JNK (JNK inhibitor II), Rho-associated kinase (Y27632), phospholipase C (U73122), and MLC kinase (ML-7). Latanoprost induced collagen gel contraction mediated by HTFs. This action of latanoprost appeared to depend on the formation of stress fibers and the activation of MAPKs, FAK, Rho-associated kinase, phospholipase C, and MLC kinase in HTFs. Latanoprost may therefore influence subconjunctival wound healing by affecting the contractility of Tenon fibroblasts.