AKT1 and Hyperglycemia: IGF-1 is a direct target of miR-142-5p and/or miR-18b, and the downregulation of these two microRNAs in the retinal tissues of DR rats and human RCVECs stimulated with hyperglycemia leads to VEGF activation by affecting the IGF-1 and AKT signaling pathways [64, 65].