MicroRNAs may provide new strategies in the treatment and diagnosis of diabetic retinopathy: Importance of VEGF

Abstract

Diabetic retinopathy (DR) is ocular microvascular complications of diabetes mellitus. Along with the increasing prevalence of diabetes worldwide, DR has come into the major cause of human blindness. Several studies have demonstrated the important roles of the expression alteration in the proteins contributed to vascular dysfunction during DR, especially vascular endothelial growth factor (VEGF). However, there is a need for further mechanistic research in this context to design new therapeutic and diagnostic programs. MicroRNAs (miRNAs, miRs) have been introduced as key controllers of gene expression in a variety of biological processes including differentiation, proliferation, and metabolism. Altered expression of miRNAs during DR development indicates a close relationship between these regulatory molecules and DR through regulating gene expressions. This review discusses and updates the functions of miRNA-dependent pathways and key roles of VEGF in the DR, which may increase our understanding and ability to target these small but important molecules to efficiently improve therapeutic and diagnostic approaches.

Keywords: Diabetic retinopathy; Gene regulation; Molecular targeting; VEGF; miRNAs.

Figure 1

miRNA biosynthesis, function, and transportation. miRNA genes are transcribed into pri-miRNAs. The pri-miRNAs are then cleaved into the pre-miRNAs by the Drosha/DGCR8 complex. After transportation from nuclear to the cytoplasm by the Ran/GTP/Exportin-5 complex, the pre-miRNAs are processed by Dicer to produce mature miRNAs, which are ready to regulate gene expression. DGCR8: Digeorge syndrome critical region 8

Figure 2

Schematic overview of the miRNAs and their effects on VEGF and other molecules contributed to the pathogenesis of diabetic retinopathy. VEGF: Vascular endothelial growth factor