The Expression of Retinal miRNA Evoked by Hyperglycemia and After Adiponectin Treatment in Human Retinal Endothelial Cells

Abstract

Background: Diabetes mellitus is a chronic metabolic disease resulting in microvascular complications including diabetic retinopathy (DR). Adiponectin (ApN) is an adipokine hormone, and recent studies demonstrated that ApN could ameliorate critical biological process involved in the pathogenesis of DR. Micro-Ribonucleic acids (miRNAs) have been documented as novel biomarkers and are increasingly considered as molecules with significant modulatory action. Aim: To characterize the miRNA profile and expression in human retinal endothelial cells (HRECs) exposed to hyperglycemic conditions (HG) and illustrate the effect of adiponectin on miRNA expression and related pathways in HRECs exposed to HG. Methods: HRECs were treated with high glucose (30mM) for 96 hours duration followed by adiponectin (30μg/ml) for 24 h. Total RNA was extracted from HRECs. The gene panel array for both adhesion and angiogenesis molecules were performed using commercial RT2 Profiler PCR arrays. Furthermore, we utilized the small RNA sequencing for microRNA expression profiling of the HRECs. Results: HG treatment increases the expression of different well-known adhesion and angiogenesis genes as well as predicted miRNAs involved in these pathways, which was counteracted by ApN. RNA-Seq for miRNA profiling revealed 13 differentially expressed miRNAs in HRECs exposed to HG. miR-146a-5p was differentially expressed in HRECs treated with ApN. Analysis pathway linked the significantly changed miRNAs induced by HG to essential pathways such as hypoxia signaling, inflammation, and oxidative stress. Conclusion: HG induces expression of various adhesion and angiogenesis genes. Using RNA-Seq technology can accurately identify dysregulated miRNA profiles in HG retinal cells. MiR-146a was upregulated by adiponectin which targets different pathways involved in DR genesis.