title: Retinal pigment epithelium cell alignment on nanostructured collagen matrices.
abstract: We investigated attachment and migration of human retinal pigment epithelial cells (primary, SV40-transfected and ARPE-19) on nanoscopically defined, two-dimensional matrices composed of parallel-aligned collagen type I fibrils. These matrices were used non-cross-linked (native) or after riboflavin/UV-A cross-linking to study cell attachment and migration by time-lapse video microscopy. Expression of collagen type I and IV, MMP-2 and of the collagen-binding integrin subunit α(2) were examined by immunofluorescence and Western blotting. SV40-RPE cells quickly attached to the nanostructured collagen matrices and aligned along the collagen fibrils. However, they disrupted both native and cross-linked collagen matrices within 5 h. Primary RPE cells aligned more slowly without destroying either native or cross-linked substrates. Compared to primary RPE cells, ARPE-19 cells showed reduced alignment but partially disrupted the matrices within 20 h after seeding. Expression of the collagen type I-binding integrin subunit α(2) was highest in SV40-RPE cells, lower in primary RPE cells and almost undetectable in ARPE-19 cells. Thus, integrin α(2) expression levels directly correlated with the degree of cell alignment in all examined RPE cell types. Specific integrin subunit α(2)-mediated matrix binding was verified by preincubation with an α(2)-function-blocking antibody, which impaired cell adhesion and alignment to varying degrees in primary and SV40-RPE cells. Since native matrices supported extended and directed primary RPE cell growth, optimizing the matrix production procedure may in the future yield nanostructured collagen matrices serving as transferable cell sheet carriers.
authors.affiliation: Institute of Anatomy, Biotechnology Center, TU Dresden, Dresden, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Ulbrich
authors.forename: Jens
authors.initials: J
authors.lastname: Friedrichs
authors.forename: Monika
authors.initials: M
authors.lastname: Valtink
authors.forename: Simo
authors.initials: S
authors.lastname: Murovski
authors.forename: Clemens M
authors.initials: CM
authors.lastname: Franz
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Müller
authors.forename: Richard H W
authors.initials: RH
authors.lastname: Funk
authors.forename: Katrin
authors.initials: K
authors.lastname: Engelmann
mesh_terms: D049109:Cell Proliferation; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D039001:Integrin alpha Chains / Q000378:metabolism; D049329:Nanostructures / Q000737:chemistry*; D055213:Retinal Pigment Epithelium / Q000737:chemistry / Q000378:metabolism*; D059008:Time-Lapse Imaging
chemical_list: D039001:Integrin alpha Chains; D003094:Collagen