ABSTRACT
Diabetic retinopathy (DR) is the leading cause of blindness in patients with diabetes. However, biomarkers for early detection of DR are still lacking. MicroRNAs (miRNAs) regulate multiple biological functions and are often deregulated in DR. We aimed to investigate whether circulating miRNAs can be used as biomarkers of early-stage DR. We used RNA-seq and qRT-PCR to identify differential serum miRNAs in patients with type 2 diabetes mellitus with DR (T2DM-DR), T2DM without DR (T2DM-no-DR), and healthy controls. We validated differential circulating miRNAs in two phases using qRT-PCR assays. RNA-seq analysis identified 7 differential circulating miRNAs between T2DM-DR and T2DM-no-DR and 47 differential miRNAs between T2DM-DR and healthy subjects. Two-stage analysis verified that a profile of five serum miRNAs (hsa-let-7a-5p, hsa-miR-novel-chr5_15976, hsa-miR-28-3p, has-miR-151a-5p, has-miR-148a-3p) was significantly associated with T2DM-DR. Receiver-operator-characteristic analyses showed that a panel of three miRNAs (hsa-let-7a-5p, hsa-miR-novel-chr5_15976, and hsa-miR-28-3p) presented 0.92 sensitivity and 0.94 specificity for distinguishing T2DM-DR from T2DM-no-DR, and 0.93 sensitivity and 0.86 specificity for differentiating early-stage T2DM-DR (NPDR) from late-stage DR (PDR). Lentivirus-mediated overexpression of hsa-let-7a-5p in human retinal microvascular endothelial cells (HRMECs) significantly promoted proliferation rates of HRMECs. In conclusion, the three-miRNA signature from serum may serve as a noninvasive diagnostic biomarker for DR. Furthermore, we showed that DR-associated miRNAs may be involved in the pathogenesis of DR, at least in part, through modifying proliferation of HRMECs.
Subject(s)
Biomarkers/blood , Diabetic Retinopathy/blood , MicroRNAs/blood , Adult , Aged , Case-Control Studies , Cell Proliferation , Endothelial Cells/metabolism , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Female , Humans , Male , Middle Aged , ROC Curve , Real-Time Polymerase Chain Reaction , Sequence Analysis, RNA , Sincalide/metabolismABSTRACT
Ursolic acid is a triterpenoid reported to inhibit the invasion of cancer cells. In this study, there was a significant increase in the gene expression of matrix metalloproteinase (MMP)-1, -2 -3, -9 and -10 in H460 cells after treatment with 10 microM ursolic acid for 24 h. Under these experimental conditions, it was found that ursolic acid induced H460 cell apoptosis. These results indicated that matrix metalloproteinase family members are involved not only in invasion, but also in apoptosis of cancer cells. It has been suggested that ursolic acid acts via a glucocorticoid receptor in the regulation of MMP. Our study also demonstrated that the localization of glucocorticoid receptor in the cytosol might be an important factor of MMP up-regulation during ursolic acid-induced H460 cell apoptosis. Ursolic acid induced a typical apoptosis on H460 cells, which was characterized by the activation of caspase-3, nuclear morphological changes and DNA fragmentation.
