LncRNA-5657 silencing alleviates sepsis-induced lung injury by suppressing the expression of spinster homology protein 2

Background: LncRNAs are closely associated with many human major diseases, however, the roles of lncRNAs in sepsis-induced lung injury remain unclear. Methods: High-throughput sequencing was used to detect the changes in lncRNA expression profile in alveolar macrophages after LPS stimulation. The BALF of patients with sepsis-induced lung injury was collected. Rats with CLP-induced septic lung injury were treated with sh-lncRNA-5657 via intravenous injection. NR8383 cells were transfected with lentiviral vectors expressing lncRNA-5657, lncRNA-5657 smart silencer, or si-spns2. The BALF cells expression levels of lncRNA-5657 and proinflammatory cytokines in BALF of patients and rats as well as in rat macrophages were measured. Changes in histopathologic score, lung wet/dry weight ratio, and spns2 expression in macrophages were examined. The relationship between lncRNA-5657 and its potential target gene spns2 was validated using a dual-luciferase reporter assay. Results: The lncRNA expression profile of LPS-stimulated macrophages demonstrated that lncRNA-5657 showed the greatest fold-change. The BALF cells of patients with sepsis-induced ARDS and the lung tissue of rats with CLP-induced sepsis had significantly increased lncRNA-5657 levels. LncRNA-5657 silencing alleviated CLP-induced lung inflammation in rats. In NR8383 cells, lncRNA-5657 overexpression enhanced, whereas lncRNA-5657 silencing attenuated the expression of proinflammatory cytokines and spns2. A dual-luciferase reporter assay showed that lncRNA-5657 interacted with the promoter of the spns2 gene. Spns2 silencing alleviated LPS-induced inflammatory response and blocked the proinflammatory function of lncRNA-5657 in alveolar macrophages. Conclusion: LncRNA-5657 is closely associated with sepsis-induce lung injury. In vitro and in vivo data demonstrated that LncRNA-5657 silencing alleviates sepsis-induced lung injury by inhibiting lung inflammatory response via suppressing spns2 expression.