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Oxidized low density lipoproteins induce a pathologic response by retinal pigmented epithelial cells
Author(s) -
Yamada Yuko,
Tian Jane,
Yang Yanqin,
Cutler Roy G.,
Wu Tinghuai,
Telljohann Richard S.,
Mattson Mark P.,
Handa James T.
Publication year - 2008
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2008.05211.x
Subject(s) - sphingomyelin , apoptosis , chemistry , oxidative stress , retinal , lipoprotein , lipid metabolism , bruch's membrane , microbiology and biotechnology , biology , cholesterol , biochemistry , retinal pigment epithelium
The accumulation of apolipoprotein B100 lipoproteins in Bruch membrane is an early event thought to promote age‐related macular degeneration (AMD). Immunohistochemistry using an anti‐oxidized low density lipoprotein antibody on 10 AMD specimens showed staining in Bruch membrane including basal deposits, a marker of AMD. To determine whether retinal pigmented epithelial cells develop a pathologic phenotype after interaction with lipoproteins, ARPE‐19 cells were exposed to low density lipoproteins (LDL) or oxidized LDLs (oxLDL). Analysis using the Affymetrix U133 Plus 2.0 (Affymetrix, Inc., Santa Clara, CA, USA) gene chip showed physiological and pathological transcriptional responses after LDL and oxLDL treatment, respectively. LDL induced a down‐regulation of cholesterol biosynthesis genes while oxLDL induced transcriptional alterations in genes related to lipid metabolism, oxidative stress, inflammation and apoptosis. Electrospray mass spectrometry showed that oxLDL, but not LDL induced large cellular increases of sphingomyelin, ceramides, and cholesteryl esters. With TUNEL labeling, oxLDL caused 14.6% apoptosis compared to <1% after LDL. Addition of an inhibitor of sphingomyelin synthase inhibited this apoptosis by 41%. These data support the hypothesis that oxidized lipoproteins are one trigger for initiating early events in the pathogenesis of AMD.