BioProject

LDL or Ox-LDL 200ug/ml, which showed no loss of viability after a 48 hour exposure, induced a physiological and pathological transcriptional response, respectively. LDL induced a downregulation of genes associated with cholesterol biosynthesis while ox-LDL induced transcriptional alterations in genes related to inflammation, matrix expansion, lipid metabolism and processing, and apoptosis. Pentraxin-3 was secreted into the culture medium after RPE cells were stimulated with ox-LDL, and immunohistochemically evident in Bruch’s membrane of human macular samples with age-related macular degeneration. ARPE-19 cells exposed to 200?g/ml ox-LDL had a 38% apoptosis rate compared to less than 1% when exposed to LDL or untreated controls (p<0.0001). While LDL induced a physiologic response by RPE cells, a pathological phenotypic response was seen after treatment with oxidatively modified LDL. The transcriptional, biochemical, and functional data provide initial support of a role for the hypothesis that modified LDLs are one trigger for initiating events that contribute to the development of age-related macular degeneration. Keywords: treatment with non-treatment control Overall design: Human ARPE-19 cells were exposed to LDL or oxidatively modified LDL (ox-LDL) for 48 hours for RNA extraction and hybridization on Affymetrix microarrays. We sought to determine whether retina, pigment epithelial cells develop a pathologic phenotype after exposure to low density lipoproteins (LDL) that are oxidatively modified.We have made two comparsions: LDL treatment versus non-treatment; ox-LDL treatment versus non-treatment.