Abstract
Purpose: :
To compare the gene expression profiles of human macular inner and outer choroidal endothelial cells and peripheral inner choroidal endothelial cells.
Methods: :
Human microvascular endothelial cells were isolated from fresh human eyes using anti-CD31 coated dynabeads. All cells were grown to approximately 80% confluence and the RNA isolated using the Qiagen RNeasy minikit. Biotinylated cRNA probes were prepared from the total RNA samples. RNA was reverse transcribed to cDNA which was then amplified by PCR and converted to cRNA The cRNA samples were then fragmented and hybridised onto Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays. The chips were scanned using Affymetrix GeneChip protocols. Comparative analysis of gene expression profiles was performed using the dCHIP software and Significance Analysis of Microarrays (SAM) The sorting and classification of significant genes into different biological processes was conducted using PANTHER.
Results: :
Examination of genes showing a two-fold or higher expression demonstrated 305 genes were differentially expressed between unpassaged proliferating human macular inner choroidal ECs and macular outer choroidal ECs. These differences were largely made up of differences in expression of genes involved in cell signalling (stromal cell derived factor 4, glycine receptor beta), cell structure and nucleic acid metabolism. Forty genes were differentially expressed between unpassaged proliferating human macular inner choroidal ECs and peripheral inner choroidal endothelial cells. Although few in number these differences were in the majority made up of genes involved in cell adhesion (cadherin 1, tetraspanin 7), cell structure (collagen XVI alpha 1), signal transduction (IL13 receptor, trefoil factor 3) fatty acid metabolism (fatty acid binding protein) and immunity (heat shock protein 70, macrophage mannose receptor).
Conclusions: :
These results demonstrate that there are few differences in gene expression in inner choroidal ECs from different ocular locations. There were more significant differences in gene expression between ECs derived from the inner and outer macular. These results may have implications for human macular neovascular disorders.
Keywords: choroid: neovascularization • gene microarray • macula/fovea