Bioinformatic analysis of retinal gene function and expression in diabetic rats

The aim of the present study was to investigate the changes in retinal gene expression at three time points and assess the underlying molecular mechanisms of diabetic retinopathy (DR) in a streptozotocin (STZ)-induced diabetes rat model using bioinformatics analysis. The gene expression profile of GSE28831 was extracted from the Gene Expression Omnibus database and differentially expressed genes (DEGs) were identified at three different time points (1, 4 and 12 weeks) using the limma package in R language. Gene ontology (GO) enrichment analysis of DEGs was performed followed by a principal component and pathway enrichment analysis of the selected DEGs along with protein-protein interaction network construction at the three time points. A total of 402, 105 and 213 DEGs were screened at 1, 4 and 12 weeks, respectively. In addition, the expression of 8 genes was identified to be significantly different at different time points, including cytochrome P450 2B2 (CYP2B2; downregulated gene; P=0.048; at 1 week), mannan binding lectin-associated serine protease-2 (MASP2; downregulated gene; P=0.044), lecithin retinol acyltransferase (LRAT; downregulated gene; P=0.015), retinal pigment epithelium (RPE)-specific protein 65 kDa (RPE65; downregulated gene; P=0.025), 11-cis-retinoldehydrogenase (RDH5; downregulated gene; P=0.04; at 4 weeks), mitogen-activated protein kinase 13 (MAPK13; upregulated gene; P=0.036), LRAT (downregulated gene; P=0.01) and RPE65 (downregulated gene; P=0.009; at 12 weeks). Furthermore, pathway enrichment and GO enrichment analyses revealed that DEGs at 4 weeks were primarily enriched in retinol metabolism and processes associated with visual functions, including 'visual perception' and 'retinol metabolism'. DEGs, including CYP2B2, MASP2, LRAT, RPE65, RDH5 and MAPK13 may be potential targets for the diagnosis and treatment of DR. Thus, the current study demonstrated that abnormal visual functions occur at 4 weeks in STZ-induced diabetic rats. This may provide a scientific basis for the diagnosis and treatment of DR because DEGs may be used to facilitate the development of novel therapeutic strategies to diagnose and treat DR.