MicroRNA-31 ameliorates LPS-induced inflammation and permeability by activating PI3K/AKT signaling pathway mediated by ROCK1 in endothelial cells

Abstract

Abstract Background and aims Evidence has shown that miR-31 is a molecule associated with inflammation in different types of cells.However,the changes of miR-31 in LPS-stimulated endothelial cells and the effect of this change in expression on endothelial cells are unknown.This study sought to investigate how miR-31 modulates endothelial permeability and inflammation in LPS-stimulated culture pulmonary microvascular endothelial cells (PMVECs). Methods It was discovered that enhanced cell monolayer permeability was defined by lower TER and higher FITC-dextran levels. Cell viability was evaluated using an MTT assay, and inflammatory factor concentration was measured using an ELISA. Western blotting and quantitative real-time PCR were utilized to quantify protein and mRNA expression. Results In LPS-stimulated PMVECs, cell permeability was increased and miR-31 levels were reduced.In PMVECs overexpressed miR-31, the increased cell permeability induced by LPS was significantly improved and the elevated levels of inflammatory factors induced by LPS were reduced. Besides,LPS-induced reductions in PI3K and AKT phosphorylation were restored by overexpressing miR-31. Inhibition of PI3K led to elevated levels of TNF-α, ICAM-1, IL-6, VCAM-1 inflammatory factor, and FITC-dextran and lower levels of TER. MiR-31 negatively controlled ROCK1 expression. The co-expression of ROCK1 and miR-31 caused the downregulation of the phosphorylated PI3K expression and decreased TER and increased FITC-dextran compared with miR-31 overexpression alone. Conclusion In response to LPS, PMVECs downregulate microRNA-31, which has been linked to PMVEC inflammation and permeability through activating the PI3K/AKT signaling cascade via ROCK1.