Alterations of circular RNAs in hyperglycemic human endothelial cells

Circular RNA (circRNA), a family of RNA generated by RNA circularization, is ubiquitously expressed in tissues and possesses increasingly important biological functions. Hyperglycemia-induced endothelial dysfunction is an initiating event in the pathogenesis of diabetes-associated cardiovascular complications. How high glucose may affect circRNAs is unknown. To address this issue, human endothelial cells were exposed to high glucose treatment and the changes of circRNAs were measured by RNA sequencing. A total 3686 circRNAs, including 1040 previously unrecorded circRNAs, were detected; and 95 different expression (DE) circRNAs were observed. The host genes of these DE circRNAs were further studied by function enrichment analyses. These analyses revealed genes of phosphoproteins, transferases, and zine finger proteins. Since circRNAs can function as a microRNA (miRNA) sponge, circRNAs-miRNAs interaction networks were explored by bioinformatics. These analyses identified a number of miRNAs, which might interact with DE circRNAs and play roles in the actions of high glucose on endothelial cells. These results demonstrate that high glucose exposure profoundly changes circRNA expression in endothelial cells. Altered circRNA expression may contribute to the effects of high glucose on endothelial function in diabetes.