title: Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.
abstract: Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p < 0.03) versus control (no intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p < 0.03) and increased expression of α-smooth muscle actin in HLE B-3 after six days, although only poly(2-hydroxyethyl methacrylate) induced a significant difference versus control (p < 0.01). Our results imply that-contrary to prior uveal biocompatibility understanding-macrophage adherence is not necessary for a strong inflammatory response to an intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal biocompatibility, specifically through the quantification of cell-surface markers of leukocyte activation.
authors.affiliation: Faculty of Engineering, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Pintwala
authors.affiliation: Faculty of Engineering, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Cameron
authors.initials: C
authors.lastname: Postnikoff
authors.affiliation: Faculty of Engineering, Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Molladavoodi
authors.affiliation: Faculty of Engineering, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada mgorbet@uwaterloo.ca.
authors.forename: Maud
authors.initials: M
authors.lastname: Gorbet
mesh_terms: D000199:Actins / Q000378:metabolism; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry; D058442:Capsule Opacification / Q000209:etiology; D002448:Cell Adhesion; D002460:Cell Line; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis; D004847:Epithelial Cells / Q000473:pathology; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007249:Inflammation / Q000209:etiology; D018836:Inflammation Mediators / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007908:Lens, Crystalline / Q000473:pathology*; D007910:Lenses, Intraocular / Q000009:adverse effects*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008422:Materials Testing; D010641:Phenotype; D011102:Polyhydroxyethyl Methacrylate / Q000009:adverse effects / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000009:adverse effects / Q000737:chemistry; D057852:Posterior Capsule of the Lens / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D001672:Biocompatible Materials; D016207:Cytokines; D018836:Inflammation Mediators; D017382:Reactive Oxygen Species; D018799:Intercellular Adhesion Molecule-1; D011102:Polyhydroxyethyl Methacrylate; D019904:Polymethyl Methacrylate
keywords: Lens epithelial cells; biocompatibility; coculture in vitro model; confocal microscopy; flow cytometry; intraocular lens biomaterials; macrophages