Bioinformatics and in vitro study reveal the roles of microRNA-346 in high glucose-induced human retinal pigment epithelial cell damage

To study microRNAs (miRNAs) and their potential effects in high glucose-induced human retinal pigment epithelial cell damage.

miR-346 is a key miRNA and plays an important role in HG-induced damage in human retinal pigment epithelial cells.

We screened the GSE52233 miRNA expression dataset for differentially expressed miRNAs (DEMs). The target genes of the top 10 DEMs were predicted using miRWalk 2.0 database, followed by function enrichment and protein-protein interaction analysis. miRNA expression was determined in the human retinal pigment epithelial cell line ARPE-19 treated with high glucose (HG) by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell proliferation was determined using cell counting kit (CCK)-8 assay. Cell cycle, apoptosis, and reactive oxygen species (ROS) levels were determined by flow cytometry. The direct interaction between miRNA and targets was validated using dual-luciferase reporter assay.

Thirty-nine DEMs were screened, and we predicted 125 miRNA-mRNA pairs for the top 10 DEMs, including 119 target genes of seven DEMs such as miR-346, which was upregulated in diabetic retinopathy (DR). miR-346 target genes were substantially enriched in the regulation of intracellular transport and retinoic acid-inducible gene I (RIG-I)-like receptor signaling pathway. Expression of three upregulated and downregulated miRNAs were verified by qRT-PCR in HG-treated ARPE-19 cells. Expression of miR-346 was elevated in HG treated ARPE-19 cells in a dose-dependent manner. HG inhibited cell proliferation and induced apoptosis, which were partly reversed by transfecting an miR-346 inhibitor, which even decreased the ROS levels elevated due to HG. Argonaute 2 (AGO2) was a target of miR-346.