Effect of transfusion-related acute lung injury on expression of intercellular adhesion molecule-1 in lung tissues of rats

Abstract

Objective To determine the changes of intercellular adhesion molecule (ICAM) - 1 protein and gene expression in plasma and lung tissues of SD rats with transfusion-related acute lung injury(TRALI) , and to investigate the role of ICAM-1 expression in the pathophysiology of TRALI. Methods Sixty SD rats were randomly divided into normal control group, lipopolysaccharide (LPS) control group, TRALI group, and positive control group (n=15 each). The normal control group was treated by sham operation. LPS control group received intravenous infusion of normal saline (approximately 1 ml/each) at 2 h after intraperitoneal injection of LPS (2 mg/kg, ≤1 min completed). TRALI group received intravenous infusion of plasma (approximately 1 ml/each) at 2h after intraperitoneal injection of LPS (2 mg/kg). The positive control group received intravenous infusion of LPS (5 mg/kg) to induce acute lung injury. Using enzyme- linked immunosorbent assay (ELISA) to determine ICAM- 1 protein in plasma and bronchoalveolar lavage fluid (BALF) of rats. ICAM - 1 protein expression in lung tissues of rats was observed by immunohistochemistry. Real-time quantitative polymerase chain reaction (RT-PCR) was used to determine ICAM-1 gene expression in lung tissues of rats. Results The expression of ICAM - 1 protein content in plasma and BALF of the positive control group and TRALI group was significantly higher than that in the normal control group and LPS control group (25.4±2.7 and 19.1±3.3 vs. 12.3±3.5 and 14.4±3.5; 23.3±2.6 and 17.2±2.9 vs. 10.5±3.2 and 12.7±3.1) (all P<0.05). The expressions of ICAM-1 protein and ICAM-1 mRNA in lung tissues of the positive control group and TRALI group were significantly higher than those in the normal control group and LPS group (69 816±7 672 and 56 908±8 823 vs. 12 908±4 836 and 18 964±5 283; 1.63±0.17 and 1.24±0.11 vs. 0.31±0.05 and 0.4±0.07) (all P<0.05). The total cell number and PMN percentage in BALF of the TRALI group [(310±76) ×106/L and (33.5±11.5)%] were significantly higher than those in the normal control group and LPS group [(101±63) ×106/L and (9.8±3.5)%] and [(165±65) ×106/L and (11.4±4.1)%] (all P<0.05). Conclusion The expression of ICAM-1 protein and ICAM-1mRNA is increased in plasma and lung tissues of TRALI rats, with increased PMN infiltration in lung tissue, suggesting that ICAM-1 may be involved in the TRALI PMN and endothelial cells adhesion and aggregation, and indicating that ICAM - 1 plays an important role in the pathophysiological process of TRALI. Key words: Acute lung injury; Transfusion - related; Intercellular adhesion molecule - 1; Neutrophils