MicroRNA Expression Analysis of Mice Retinas with Oxygen-Induced Retinopathy by RNA Sequencing

Abstract

Purpose. To characterize the microRNA (miRNA) expression profiles in the retinas of mice with oxygen-induced retinopathy by RNA sequencing and to ascertain miRNAs associated with retinal neovascularization. Methods. Retina samples were obtained from 3 groups (6 retinas/group) of OIR mice and normal mice at P17. RNA was isolated from 24 retina samples and then detected on an Illumina HiSeq. Twelve retina samples were used for quantitative polymerase chain reaction to validate the RNA sequencing. Bioinformatics analyses were performed. Result. The RNA sequence showed that 565 miRNAs were detected in the retina of OIR mice and 583 miRNAs in the retina of normal control mice. A total of 553 miRNAs were expressed in both groups. Thirty-eight miRNAs showed altered expression in both groups ( $p\le 0.05$ ). Compared with the control group, 2 miRNAs were significantly upregulated in the OIR group, while 36 miRNAs were significantly downregulated. Meanwhile, 2 candidate miRNAs (miR-181a-5p and miR-21a-5p) with significant differences in miRNA expression ( $p<0.01$ ) were selected for validation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to confirm the relative expression of the two miRNAs. Bioinformatics analyses showed that pathways involved in ischemic retinopathy (such as TGF-β, Ras, Hippo, PI3K-Akt, VEGF, and HIF-1 signaling pathways) were enriched. Conclusions. Our study provided an overall view of miRNA profiling in the OIR retina. These miRNA profiles provide a valuable framework for the potential therapy of retinal angiogenesis.