A microarray analysis of retinal transcripts that are controlledby image contrast in mice

[摘要] Purpose: The development of myopia is controlled by still largelyunknown retinal signals. The aim of this study was to investigate thechanges in retinal mRNA expression after different periods of visualdeprivation in mice, while controlling for retinal illuminance.Methods: Each group consisted of three male C57BL/6 mice. Treatmentperiods were 30 min, 4 h, and 6+6 h. High spatial frequencies werefiltered from the retinal image by frosted diffusers over one eye whilethe fellow eyes were covered by clear neutral density (ND) filters thatexhibited similar light attenuating properties (0.1 log units) as thediffusers. For the final 30 min of the respective treatment period micewere individually placed in a clear Perspex cylinder that was positionedin the center of a rotating (60 degrees) large drum. The inside of thedrum was covered with a 0.1 cyc/degree vertical square wave grating.This visual environment was chosen to standardize illuminances andcontrasts seen by the mice. Labeled cRNA was prepared and hybridized toAffymetrix GeneChip® Mouse Genome 430 2.0 arrays. Alterations inmRNA expression levels of candidate genes with potential biologicalrelevance were confirmed by semi-quantitative real-time reversetranscription polymerase chain reaction (RT-PCR).Results: In all groups, Egr-1 mRNA expression was reduced indiffuser-treated eyes. Furthermore, the degradation of the spatialfrequency spectrum also changed the cFos mRNA level, with reducedexpression after 4 h of diffuser treatment. Other interesting candidateswere Akt2, which was up-regulated after 30 min of deprivation andMapk8ip3, a neuron specific JNK binding and scaffolding protein thatwas temporally regulated in the diffuser-treated eyes only.Conclusions: The microarray analysis demonstrated a pattern ofdifferential transcriptional changes, even though differences in theretinal images were restricted to spatial features. The candidate genesmay provide further insight into the biochemical short-term changesfollowing retinal image degradation in mice. Because deprivation ofspatial vision leads to increased eye growth and myopia in both animalsand humans, it is believed some of the identified genes play a role inmyopia development.

[学科分类] 生物化学/生物物理