miR-1 and miR-802 regulate mesenchymal-epithelial transition during kidney development by regulating Wnt-4/β-catenin signaling.

Objective: Mesenchymal-epithelial transition (MET) is an important part of kidney development. However, the role of microRNA (miRNA) in MET and the regulating mechanism is still not well known.

Materials And Methods: qRT-PCR and western blot were performed to detect the expression of miR-1 and miR-802 and related protein expression. Luciferase reporter assay and western blot were used to identify the target of miR-1 and miR-802. Confocal microscopy was used to analyze the MET process.

Results: We demonstrated that miR-1 expression was downregulated and miR-802 expression was upregulated during kidney development. And during the process, proteins levels of Wnt-4 and β-catenin changed significantly. In MDCK cells, overexpression of Wnt-4 inhibited the expression of β-catenin, and promote the MET, and overexpression of β-catenin inhibited MET. Further studies suggested that miR-1 and miR-802 regulated MET by binding to Wnt-4 and β-catenin mRNA, regulated the expression of Wnt-4 and β-catenin. In conclusion, miR-1 and miR-802 regulate MET during kidney development by regulating Wnt-4/β-catenin signaling.