Down-regulation of microRNA-126-5p contributes to overexpression of VEGFA in lipopolysaccharide-induced acute lung injury.

Abstract

To investigate the role of microRNA-126-5p (miR-126-5p) in acute lung injury induced by bronchial instillation of lipopolysaccharide (LPS), and to explore the potential target(s) of miR-126-5p in acute lung injury. In the mice with LPS-induced acute lung injury, the level of miR-126-5p in the pulmonary tissues was decreased by 41% whilst pulmonary vascular endothelial growth factor-A (VEGFA) doubled in its mRNA content and increased threefold in its protein level. Similar results were observed in the alveolar type II (ATII) cells treated with LPS. By using luciferase reporter assay, we found that miR-126-5p inhibited VEGFA expression by targeting its 3'-untranslated region. In addition, overexpression of miR-126-5p attenuated LPS-induced reduction of epithelial sodium channel and aquaporin 1 in ATII cells MiR-126-5p was down-regulated in LPS-induced acute lung injury in mice. Thus overexpression of miR-126-5p may alleviate acute lung injury by down-regulating VEGFA.