title: Biological effects of native and oxidized low-density lipoproteins in cultured human retinal pigment epithelial cells.
abstract: Age-related macular degeneration (AMD) and artherosclerosis share common characteristics in their pathogenesis. In this study, we investigated the effects of lipoproteins like native (n)-LDL, oxidized (ox)-LDL and high-density lipoprotein (HDL) on advanced senescence, extracellular matrix accumulation, cell loss, and transforming growth factor-beta2 (TGF-beta2) expression in cultured human retinal pigment epithelial (RPE) cells. Primary human RPE cells were incubated with 10-100 microg/ml n-LDL, ox-LDL, and HDL for 24h. For determination of advanced senescence, beta-galactosidase staining was used. The induction of fibronectin (Fn), laminin alpha 1 (Laa1), and collagen type IV alpha 2 (Col4a2) mRNA was quantified by real-time PCR. Cell loss was investigated by live dead assay. Expression of TGF-beta2 was analyzed by real-time PCR and ELISA assays. Ox-LDL accelerated dose-dependently the onset of RPE senescence, whereas LDL and HDL had no effect. LDL and ox-LDL led to induced expression of Fn, Laa1 and Col4a2, whereas HDL had no influence. Incubation of RPE cells with 100 microg/ml ox-LDL induced marked cell death compared to untreated control cells. Expression of TGF-beta2 was dose-dependently increased by LDL and ox-LDL. LDL and ox-LDL induced cellular changes in RPE cells in vitro, which may resemble pathogenic events of AMD. These results may provide further information about the effects of LDL and ox-LDL in the human RPE and their potential role in the pathogenesis of AMD.
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Alice L
authors.initials: AL
authors.lastname: Yu
authors.forename: Reinhard L
authors.initials: RL
authors.lastname: Lorenz
authors.forename: Christos
authors.initials: C
authors.lastname: Haritoglou
authors.forename: Anselm
authors.initials: A
authors.lastname: Kampik
authors.forename: Ulrich
authors.initials: U
authors.lastname: Welge-Lussen
mesh_terms: D000328:Adult; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects; D008076:Cholesterol, HDL / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008268:Macular Degeneration / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000187:drug effects*; D053781:Transforming Growth Factor beta2 / Q000096:biosynthesis / Q000235:genetics
chemical_list: D008076:Cholesterol, HDL; D016326:Extracellular Matrix Proteins; D008077:Lipoproteins, LDL; D012333:RNA, Messenger; D053781:Transforming Growth Factor beta2; C099252:oxidized low density lipoprotein