Abstract
Purpose: :
To detect retinal transcripts that change during a short period of spatially degraded retinal images, while controlling for differences in retinal image brightness.
Methods: :
Three male C57BL/6 mice, aged 30 days, were treated with a diffuser for 30 minutes over one eye while the fellow eye was fitted with a clear neutral density filter with matched light attenuation. Animals were individually placed in the center of a rotating large drum (60 deg/sec), covered inside with a 0.1 cyc/deg vertical square wave grating. Labeled cRNA was prepared from the six retinas and hybridized to Affymetrix GeneChip® Mouse Genome 430 2.0 arrays with more than 34000 characterized genes. Alterations in gene expression of candidates with potential relevance were verified by semi–quantitative real–time reverse transcription polymerase chain reaction (RT–PCR), using SYBR Green I (Qiagen).
Results: :
Significant changes were detected in the expression levels of 191 transcripts. 151 (∼79%) genes were down–regulated and 40 (∼21%) up–regulated in the diffuser treated eyes, relative to the ND filter treated references. 13% of the differentially expressed genes were involved in signal transduction. Of the 12 genes chosen for validation by semi–quantitative real–time RT–PCR, 8 could be confirmed, with a significant correlation between both techniques. Krt2–6b, NfΚbie and Akt2 were up–regulated in the diffuser–treated eyes, whereas Runx2, Ptx3, Htr1d, Zfp75 and Myb were down–regulated.
Conclusions: :
The microarray analysis provided a rich pattern of transcriptional changes, even though the differences in the retinal images were confined to spatial. The candidates provide further insight into the biochemical short–term changes, following retinal image degradation. Since poor retinal image quality induces myopia in both animal models and humans, some of the identified genes should play a role in myopia.
Keywords: myopia • gene/expression • retina