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Series GSE50195 Query DataSets for GSE50195
Status Public on Dec 23, 2013
Title Expression data for human retinal pigment epithelium (RPE)/choroid - early age-related macular degeneration (AMD) and control samples
Organism Homo sapiens
Experiment type Expression profiling by array
Summary Purpose: Age-related degeneration (AMD) is a major cause of blindness in developed countries. The molecular pathogenesis of early events in AMD is poorly understood. We investigated differential gene expression in samples of human retinal pigment epithelium (RPE)/choroid from early AMD and control maculas using exon-based arrays. Methods: Gene expression levels in nine early AMD and nine control human donor eyes were assessed using Affymetrix Human Exon ST 1.0 arrays. Two controls did not pass quality control and were removed. Differentially expressed genes were annotated using DAVID, and gene set enrichment analysis (GSEA) was performed on RPE-specific and endothelium-associated gene sets. CFH genotype was also assessed and differential expression was analyzed with respect to high AMD risk (YH/HH) and low AMD risk (YY) genotypes. Results: Seventy-five genes were identified as differentially expressed (raw p-value < 0.01; >50% fold change, mean log2 expression level in AMD or control ≥ median of all average gene expression values); however, no genes were significant (adj. p-value < 0.01) after correction for multiple hypothesis testing. Of 52 genes with decreased expression in AMD (fold change < 0.5; raw p-value < 0.01), 18 genes were identified by DAVID analysis as associated with vision or neurological processes. GSEA of RPE-associated and endothelium-associated genes revealed a significant decrease in genes typically expressed by endothelial cells in the early AMD group compared to controls, consistent with previous histologic and proteomic studies. Analysis with respect to CFH genotype indicated decreased expression of ADAMTS9 in eyes with high-risk genotypes (fold change = -2.61; raw p-value = 0.0008). Conclusions: GSEA results suggest that RPE transcripts are preserved or elevated in early AMD, concomitant with loss of endothelial cell marker expression. These results are consistent with the notion that choroidal endothelial cell dropout occurs early in the pathogenesis of AMD.
 
Overall design Using AltAnalyze (ver. 2.0.7 beta), we analyzed nine early AMD and nine control eyes using Affymetrix Human Exon ST 1.0 arrays. Following initial processing in AltAnalyze, two control arrays were identified as potential outliers by tests implement in arrayQualityMetrics, a package for R.
 
Contributor(s) Whitmore SS, Braun TA, Skeie JM, Haas CM, Sohn EH, Stone EM, Scheetz TE, Mullins RF
Citation(s) 24265543
Submission date Aug 26, 2013
Last update date Dec 26, 2013
Contact name S. Scott Whitmore
Organization name The University of Iowa
Department The University of Iowa Institute for Vision Research
Street address 375 Newton Road
City Iowa City
State/province IA
ZIP/Postal code 52242
Country USA
 
Platforms (1)
GPL17629 [HuEx-1_0-st] Affymetrix Human Exon 1.0 ST Array [AltAnalyz probeset-to-Ensembl mapping]
Samples (16)
GSM1215520 RPE/choroid-AMD-1
GSM1215521 RPE/choroid-AMD-2
GSM1215522 RPE/choroid-AMD-3
Relations
BioProject PRJNA217084

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Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE50195_RAW.tar 481.7 Mb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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