Effects of ulinastatin on toll-like receptor 4 signaling pathway in lung tissue of rats after lipopolysaccharide insult / 中华急诊医学杂志

ABSTRACT

Objective To investigate the protective mechanisms of ulinastatin (UTI) in lung injury in septic rats.Methods Thirty healthy SD rats of clean grade were randomly (random number) divided into saline control group,lipopolysaccharide (LPS) group and lipopolysaccharide + ulinastatin (LPS + UTI) group (n =10,in each).The lung tissues were obtained for morphological observation at the 24th-hour after LPS injection.RT-PCR or Western blot,ELISA methods were applied to measure the expressions of Toll-like receptor 4 (TLR4),nuclear factor (NF)-κB,tumor necrosis factor (TNF)-α mRNA and their protein levels.Results LPS injection could result in lung injury.UTI could down-regulate the expressions of TLR4 mRNA (t =3.563,P =0.032),TNF-α mRNA (t =5.147,P =0.028),TLR4 protein (t =2.692,P =0.041),NF-κB protein (t =2.459,P =0.024) and TNF-α protein (t =3.336,P =0.037) in lung,and could in turn alleviate lung injury.Conclusions UTI showed protective effects on LPS induced lung injury,and one of the mechanisms was perhaps associated with the inhibition of TLR4-NF-κB signal transduction pathway.