lncRNA NEAT1 aggravates sepsis-induced lung injury by regulating the miR-27a/PTEN axis.

Sepsis is an acute inflammatory reaction and a cause of acute respiratory distress syndrome (ARDS). In the present study, we explored the roles and underlying mechanism of the lncRNA Nuclear enriched abundant transcript 1 (NEAT1) in ARDS. The expression levels of genes, proteins and pro-inflammatory cytokines in patients with ARDS, LPS-stimulated cells and septic mouse models were quantified using qPCR, western blotting and ELISA assays, respectively. The molecular targeting relationship was validated by conducting a dual-luciferase reporter assay. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The cell cycle phase was determined by flow cytometry assay. The expression levels of NEAT1 and pro-inflammatory cytokines were higher in patients with ARDS and septic models than in controls. Knockdown of NEAT1 significantly increased cell proliferation and cycle progression and prolonged mouse survival in vitro and in vivo. Mechanistically, miR-27a was identified as a downstream target of NEAT1 and directly inhibited PTEN expression. Further rescue experiments revealed that inhibition of miR-27a impeded the promoting effects of NEAT1 silence on cell proliferation and cycle progression, whereas inhibition of PTEN markedly weakened the inhibitory effects of NEAT1 overexpression on cell proliferation and cycle progression. Altogether, our study revealed that NEAT1 plays a promoting role in the progression of ARDS via the NEAT1/miR-27a/PTEN regulatory network, providing new insight into the pathologic mechanism behind ARDS.