Silencing of miR-486 alleviates LPS-stimulated inflammatory response of macrophages through targeting SIRT1.

Abstract

Previous studies identified that microRNAs (miRNAs) have promising diagnostic and prognostic value against sepsis. MiR-486 was demonstrated to be upregulated in sepsis. However, the detailed role and underlying mechanism of miR-486 in the inflammatory response of sepsis are still unclear. In this research, macrophages were stimulated with lipopolysaccharide (LPS) to establish a sepsis model in vitro. qRT-PCR was used to detect miR-486 expression and the mRNA levels of sirtuin (SIRT1), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β. ELISA assay was performed to measure the levels of TNF-α, IL-6 and IL-1β. SIRT1 protein expression was determined by Western blot analysis. The targeted relationship of miR-486 and SIRT1 was confirmed by dual-luciferase reporter assay. Our data supported that miR-486 was upregulated in the serum of sepsis patients. MiR-486 expression and inflammatory response were elevated by LPS stimulation in macrophages. MiR-486 silencing or SIRT1 overexpression alleviated inflammatory response in LPS-stimulated macrophages. Moreover, SIRT1 was a direct target of miR-486. Anti-miR-486-mediated anti-inflammatory response in LPS-stimulated macrophages was antagonized by SIRT1 inhibition. Our data suggested that miR-486 silencing alleviated inflammatory response in macrophages under LPS stimulation at least partly through targeting SIRT1. Targeting miR-486 may provide a novel way to protect against dysregulated inflammatory response in sepsis patients.