Abstract
Purpose :
Glaucoma is a complex trait involving genetic, aging, and environmental factors. Recent studies indicate that miRNAs are involved in the development of glaucoma. However, it is not clear how miRNAs contribute to this disease. To move this field forward, it is essential to systematically address whether miRNA-mediated gene expression changes are responsible for glaucoma onset and progression. The DBA/2J (D2) strain is widely used to study of causes and treatment of glaucoma because it accurately models main features of human glaucoma. This study takes advantage of D2 mouse model to investigate the role of miRNAs in the progression of glaucoma.
Methods :
Total RNA and miRNA were extracted from retina of D2 and D2-Gpnmb+ control mice at six time points ranged from 1~15 months. They were hybridized to Affymetrix Mouse Gene 2.0ST and GeneChip miRNA arrays, following protocols. Expression data were normalized using RMA method. Differential expression of genes and miRNAs were analyzed using two-way ANOVA and Rnits package. GO enrichment, gene-disease annotation, and miRNA target prediction were performed using DAVID, human-mouse disease connection and miRWalk2.0.
Results :
A total of 50 genes (fold change ≥2, p ≤0.05) and 132 miRNAs (fold change ≥1.5, p ≤0.05) were differentially expressed between D2 and wildtype. GO enrichment revealed that those genes are significantly involved in the eye (p = 6.44E-14), visual sensation (p = 1.35E-12), and eye development (p = 1.75E-6). Gene-disease annotation showed that 24 genes have been associated with eye related phenotypes or disease. Target prediction revealed that 94 miRNAs bind 41 of the differentially expressed genes. Some of these miRNAs, such as miR-214-5p and miR-9-5p, have been previously implicated in glaucoma. These miRNAs are preferentially upregulated at the onset of glaucoma and display negative correlation with target genes, some of which are known glaucoma-associated genes, such as Ogn, Sfrp1, Mip, and Gpnmb.
Conclusions :
Fifty genes were differentially expressed between retinae from D2 and control. About 36% of them are targeted by miRNAs whose expression has negative correlation with their target and had significant difference between D2 and D2-Gpnmb+. This suggests that a subset of glaucoma-associated genes are involved in the development of glaucoma through miRNA regulation. Our findings demonstrate that miRNAs are biomarkers and potential therapeutic targets for glaucoma.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.