title: Involvement of protein kinase C in phagocytosis of human retinal pigment epithelial cells and induction of matrix metalloproteinase secretion.
abstract: Protein kinase C (PKC) is involved in cell activation. We investigated PKC-mediated pathways and secretion of matrix metalloproteinases (MMPs) in phagocytosis by human retinal pigment epithelial cells (RPE). We used time-resolved fluorometry for europium-labeled microsphere uptake and gel zymography to assay the influence of PKC modulators. PKC inhibitors blocked phagocytosis by RPE. ARPE-19, a human RPE-cell line, showed reduced secretion of MMP-2, although MMP-9 secretion by PKC activation was conserved in both cell types, namely in the primary RPEs and in the RPE-cell line. Particle uptake by RPE cells requires activation of PKC; the use of PKC inhibitors as new anticancer drugs may possibly cause ocular side-effects.
authors.affiliation: Clinical Department of Ophthalmology, Innsbruck Medical University, 6020 Innsbruck, Austria. eveline.schretter-irschick@i-med.ac.at
authors.forename: Eveline U
authors.initials: EU
authors.lastname: Irschick
authors.forename: Gertrud
authors.initials: G
authors.lastname: Haas
authors.forename: Josef
authors.initials: J
authors.lastname: Troger
authors.forename: Florian
authors.initials: F
authors.lastname: Ueberall
authors.forename: Hartwig P
authors.initials: HP
authors.lastname: Huemer
mesh_terms: D002478:Cells, Cultured; D015536:Down-Regulation; D004789:Enzyme Activation; D005063:Europium; D005470:Fluorometry; D006801:Humans; D049408:Luminescent Agents; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008863:Microspheres; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D055213:Retinal Pigment Epithelium / Q000166:cytology* / Q000502:physiology*
chemical_list: D049408:Luminescent Agents; D047428:Protein Kinase Inhibitors; D005063:Europium; D011493:Protein Kinase C; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9