Abstract
Purpose:
MicroRNAs (miRNAs) are known to participate in post-transcriptional regulation of gene expression and are involved in multiple pathogenic processes. It was recently reported that the some miRNAs change in expression levels during the development and progression of various diseases such as cancer and diabetes. The purposes of this study were to identify miRNA expression changes in the retinas of Akita mice, a genetic model of type 1 diabetes and to elucidate the potential role of miRNA in diabetic retinopathy.
Methods:
miRNA expression changes in the retinas of Akita mice were identified by miRNA-specific microarray and confirmed by quantitative reverse transcription (RT)-PCR (qRT-PCR). The potential downstream targets of identified miRNAs were predicted by bioinformatics analysis using web-based applications and confirmed by dual-luciferase assay. The mRNA and protein levels of identified downstream targets of miRNA were examined by qRT-PCR and Western blot analysis.
Results:
miRNA-specific microarray and qRT-PCR showed that miR-184 was significantly down-regulated in the retina of Akita mice. Bioinformatics analysis predicted that some components in Wnt signaling may be regulated by miR-184. Thus, we identified that Wnt signaling activity was significantly down-regulated by the transfection of miR-184 precursor (mimic) and over expression of miR-184, whereas it was up-regulated by the transfection of anti-sense miR-184 (inhibitor). Furthermore, we will identify the downstream target genes regulated by miR-184 using dual-luciferase assay.
Conclusions:
It is suggested that aberrant activation of Wnt signaling pathway in the diabetic retina may cause pathogenesis of diabetic retinopathy. Current study suggests that down-regulation of miR-184 in diabetes may lead to activation of Wnt signaling in the retina, which plays an important role in the pathogenesis, development and progression of diabetic retinopathy.
Keywords: 533 gene/expression •
535 gene microarray •
499 diabetic retinopathy