Expression of microRNA-181b in sepsis-induced acute lung injury rats and its correlation with the levels of inflammatory cytokines

Abstract

Objective To investigate the differential expression of microRNA (miRNA, miR)-181b in sepsis-induced acute lung injury (ALI) and its correlation with interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Methods Twenty-four SD male rats were randomly divided into 4 groups: normal control group, 3-h sepsis group, 6-h sepsis group, and 12-h sepsis group in equal number. Sepsis-induced ALI model was induced by intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg). The injury of lung tissue was evaluated histopathologically. The expression of miR-181b was detected by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 and TNF-α were measured by enzyme linked immunosorbent assay (ELISA) and the correlation analysis was carried out. Results The lung tissue hematoxylin -eosin staining indicated ALI model was successfully established in the sepsis group. The expression level of miR-181b in the lung tissue of the sepsis group (6 h) was 0.41±0.05 respectively, which was significantly lower than that in the normal control group (P=0.002). The expression of miR-181b in the lung tissue of the sepsis group (6 h) was negatively correlated with the level of IL-6 and TNF-α (r=-0.985, P=0.000; r=-0.990, P=0.000). Conclusion The expression level of miR-181b was significantly down-regulated in sepsis-induced ALI, and had a significantly negative correlation with IL-6 and TNF-α. Key words: MicroRNA-181b; Sepsis; Acute lung injury; Inflammatory cytokines