Gene expression changes in the retina following optic nervetransection

[摘要] Purpose: To obtain and analyze the gene expression profiles of theretina following optic nerve transection (ONT).Methods: An axotomy animal model was generated by taking a crosssection of the optic nerve with care not to damage the adjacent bloodsupply. The extent of cell loss was evaluated by counting cells in theganglion cell layer (GCL) of flat-mounted retinas stained with cresylviolet. Gene expression profiles of control and ONT retinas wereanalyzed with Agilent's rat oligo microarray slides. Differentiallyexpressed genes were identified from three independent experiments andclustered based on their functions with expression analysis systematicexplorer software. Real-time quantitative and semiquantitative RT-PCRwere used to validate changes in gene expression levels.Results: Gene expression changes in axotomized retinas were analyzedwith rat oligo microarray slides containing 22,575 oligonucleotideprobes that represent over 20,000 genes and expressed sequence tags(ESTs). The expression of 493 genes was increased more than 1.5 fold,including 85 that were upregulated more than 2 fold, and the expressionof 113 genes was decreased 1.5 fold or more, including 21 that weredownregulated more than 2 fold. Differentially expressed genes wereclustered based on their functions. Several novel genes expressed in theGCL have been identified and their expression patterns in differenttissues were analyzed. Among the genes differentially regulated inretinas with induced retinal ganglion cell (RGC) death, we haveidentified 13 genes that are mapped to known glaucoma loci and can beconsidered for mutation screening in patients with inherited forms ofglaucoma.Conclusions: The gene expression profiles of the ONT retinas can beused to identify RGC-expressed genes, which may be essential for themorphological and physiological characteristics of RGCs. The results ofthis study can also be used to evaluate the molecular changes takingplace in the retina in response to RGC loss.

[学科分类] 生物化学/生物物理