Retinal Pigment Epithelial Cell Behavior is Modulated by Alterations in Focal Cell–Substrate Contacts

Abstract

To investigate how the cellular behavior of cultured retinal pigment epithelial (RPE) cells was affected by the manipulation of early focal contact. To manipulate early focal contact, a reduced focal cell-substrate contact area on the micropatterned surfaces was implemented by microfabrication with polydimethylsiloxane (PDMS). The micropatterned PDMS surfaces had a circular pillar with a diameter of 5 microm. The human retinal pigment epithelial cell line, ARPE-19, was seeded onto the fibronectin-coated PDMS surfaces. Cell adhesion, growth, cell cycle, morphology, and interleukin-6 (IL-6) expression were observed for 3 weeks. The fluorescent images of localized vinculin and actin stress fibers appeared to be more prominent on smooth PDMS surfaces. Although there was no significant effect on cell adhesion, a statistically significant inhibition of cell cycle progression was observed for micropatterned PDMS surfaces. Similarly, micropatterned surfaces showed significantly less cell growth than that of smooth surfaces. Cultures over a period of 3 weeks showed a distinct cell-cell phenotype discrepancy. Furthermore, IL-6 mRNA and secreted protein induced by IL-1beta in ARPE-19 were downregulated on micropatterned PDMS surfaces. Disturbed focal contact in ARPE-19 cells grown on micropatterned surfaces altered cell cycle, growth, morphology, and the expression of IL-6 in vitro.