MicroRNA-19a regulates lipopolysaccharide-induced endothelial cell apoptosis through modulation of apoptosis signal-regulating kinase 1 expression

Background: MicroRNAs, small non-encoding RNAs that post-transcriptionally modulate expression of their target genes, have been implicated as critical regulatory molecules in endothelial cells. Results: In the present study, we found that overexpression of miR-19a protects endothelial cells from lipopolysaccharide (LPS)-induced apoptosis through the apoptosis signal-regulating kinase 1 (ASK1)/p38 pathway. Quantitative real-time PCR demonstrated that the expression of miR-19a in endothelial cell was markedly down-regulated by LPS stimulation. Furthermore, LPS-induced apoptosis was significantly inhibited by over-expression of miR-19a. Finally, both a luciferase reporter assay and western blot analysis showed that ASK1 is a direct target of miR-19a. Conclusions: MiR-19a regulates ASK1 expression by targeting specific binding sites in the 3' untranslated region of ASK1 mRNA. Overexpression of miR-19a is an effective method to protect against LPS-induced apoptosis of endothelial cells.