MicroRNA-200b Expression in the Vitreous Humor of Patients with Proliferative Diabetic Retinopathy.

BACKGROUND: The role of microRNA (miRNA)-200b in the pathogenesis of proliferative diabetic retinopathy (PDR) has been studied in diabetic animal models. The aim of this study was to assess miRNA-200b expression in the vitreous of patients with PDR and to determine its correlation with vascular endothelial growth factor (VEGF), one of the pathogenic mechanisms in PDR. METHODS: Quantitative reverse transcription polymerase chain reaction was used to measure miRNA-200b expression in the vitreous from 29 eyes with PDR and 30 eyes with idiopathic macular holes (IMH; control group). Vitreous VEGF was measured using an enzyme-linked immunosorbent assay. RESULTS: miRNA-200b expression was about 5-fold increased in the vitreous samples from eyes with PDR compared with the controls (p ≤ 0.001). Vitreous VEGF expression was also significantly higher in the PDR group than in the IMH group (p ≤ 0.001), but no significant correlation was found between miRNA-200b and VEGF. CONCLUSION: Both miRNA-200b and VEGF are increased in the vitreous of patients with PDR but in a noncorrelated pattern. miRNA-200b may be involved in the pathogenesis of PDR but through VEGF-independent mechanisms. Further studies are needed to identify the miRNA-200b-targeted genes involved in the pathogenesis of PDR and to examine the potential role of miRNA-200b as a target for PDR treatment.

Differentially expressed microRNAs in maternal plasma for the noninvasive prenatal diagnosis of Down syndrome (trisomy 21).

OBJECTIVES: Most developmental processes are under the control of small regulatory RNAs called microRNAs (miRNAs). We hypothesize that different fetal developmental processes might be reflected by extracellular miRNAs in maternal plasma and may be utilized as biomarkers for the noninvasive prenatal diagnosis of chromosomal aneuploidies. In this proof-of-concept study, we report on the identification of extracellular miRNAs in maternal plasma of Down syndrome (DS) pregnancies. METHODS: Using high-throughput quantitative PCR (HT-qPCR), 1043 miRNAs were investigated in maternal plasma via comparison of seven DS pregnancies with age and fetal sex matched controls. RESULTS: Six hundred and ninety-five miRNAs were identified. Thirty-six significantly differentially expressed mature miRNAs were identified as potential biomarkers. Hierarchical cluster analysis of these miRNAs resulted in the clear discrimination of DS from euploid pregnancies. Gene targets of the differentially expressed miRNAs were enriched in signaling pathways such as mucin type-O-glycans, ECM-receptor interactions, TGF-beta, and endocytosis, which have been previously associated with DS. CONCLUSIONS: miRNAs are promising and stable biomarkers for a broad range of diseases and may allow a reliable, cost-efficient diagnostic tool for the noninvasive prenatal diagnosis of DS.