Dasatinib affects focal adhesion and myosin regulation to inhibit matrix contraction by Müller cells. (October 2015)

• Record Type: Journal Article
• Authors: Tsukahara, Rintaro; Umazume, Kazuhiko; Yamakawa, Naoyuki; McDonald, Kevin; Kaplan, Henry J.; Tamiya, Shigeo
• Is Part Of: Experimental eye research. Volume 139(2015:Oct.)
• Page Start: 90
• Page End: 96
• Publication Date: 2015-10
• Subjects: Müller cells -- Epiretinal membrane -- Contraction -- Dasatinib -- Focal adhesion -- Stress fibers; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2015.07.019
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Epiretinal membrane (ERM) contraction is associated with a variety of ocular diseases that cause macular dysfunction. Trans-differentiated Müller cells have been identified in ERMs, and have been implicated to be involved in the contractile process. In this study, we tested the effect of dasatinib, an FDA-approved tyrosine kinase inhibitor, on matrix contraction caused by Müller cells, and examined molecular mechanism of action. Type I collagen matrix contraction assays were used to examine the effect of drugs on matrix contraction by trans-differentiated Müller cells. Fluophore-conjugated phalloidin was used for the detection of actin cytoskeleton, and Western-blot analyses were carried out to examine protein expression and phosphorylation status. Dasatinib inhibited collagen matrix contraction by trans-differentiated Müller cells that was associated with decreased cell spreading and reduction of actomyosin stress fibers. Concomitantly, dasatinib-treated Müller cells had reduced phosphorylation of Src family kinase, paxillin, as well as myosin II light chain. Specific inhibitors of Rho/ROCK and myosin II confirmed the critical role played by this pathway in Müller cell contraction. Our data demonstrate that dasatinib significantly reduced matrix contraction by Müller cells via inhibition of focal adhesion, as well as actomyosin contraction. Highlights: Dasatinib, a tyrosine kinase inhibitor, prevents matrix contraction by Müller cells. Dasatinib targets key focal adhesion proteins involved in cell-matrix adhesion. Dasatinib treatment reduces actomyosin stress fibers expression. Rho/ROCK/myosin light chain pathway is essential for Müller cell contraction.