OBJECTIVETo investigate the transduction pathway of triggering receptor-1 expressed on myeloid cells (TREM-1) in acute lung injure induced by paraquat in rats through the activating or blocking TREM-1, to observe the effect of signal transduction pathway in the acute lung injure induced-paraquat.

METHODS80 SD rats were randomly divided into normal saline control group (n=20) , PQ poisoning group (n=20) , antibody group (n=20) , and LP17 group (n=20). poisoning group, antibody group and LP17 group were given saline diluting PQ 80 mg/kg of disposable lavage after 2 h, a single set of intraperitoneal injection of anti-TREM-1 mAb (250 g/kg) , tail intravenous LP17 group synthetic peptide (3.5 mg/kg) , poisoning group was given equal normal saline intraperitoneal injection, control group given normal saline 1 mg/kg after 2 h after lavage, given the amount of intraperitoneal injection of saline solution. The expression of NF-κB in lung tissue was determined by immunohistochemistry.The levels of TNF-a, IL-10, TREM-1, and soluble TREM-1 (sTREM-1) in lung tissue and serum were measured by ELISA. Pathology changes of lung were observed under light microscope, and lung score of pathology was compared.

RESULTSAdministration of anti-TREM-1 mAb after PQ poisoning modeling significantly increased the NF-κB expression in lung tissue at 48 h, resulting in a large number of pro-inflammatory cytokines releasing in the lung tissue and serum and lung pathology injury score increasing.Administration of LP17 after modeling significantly down-·regulated the expressions of NF-κB and proinflammatory cytokines, while led to a slight increase of anti-inflammatory cytokines and a decline of lung pathology injury score.

CONCLUSIONTREM-1 may involve in inflammatory response by promoting the generation of inflammatory factors via NF-κB pathway, thus lead to lung pathological changes.