Change in expression of nuclear factor-κB and intercellular adhesion molecule-1 in lung tissues of rats with transfusion-related acute lung injury and its significance

Abstract

Objective To determine the change in the expression of nuclear factor-κB (NF-κB) and intercellular adhesion molecule 1 (ICAM-1) in the lung tissues of rats with transfusion-related acute lung injury, and to investigate its clinical significance. Methods Sixty SD rats were randomly divided into the normal control group, lipopolysaccharide (LPS) control group, TRALI group and positive control group (n=15 each) . The normal control group was treated with sham operation. The LPS control group was intraperitoneally injected with LPS (2 mg/kg, completed within ≤ 1 min) , and was given intravenous infusion of normal saline at 2 h (about 1 ml/rat) . The TRALI group was treated with intravenous infusion of blood (about 1 ml/rat) at 2 h after intraperitoneal injection of LPS (2 mg/kg) . The positive control group was treated with intravenous infusion of LPS (5 mg/kg) to induce acute lung injury. The sediment of bronchial alveolar lavage fluid (BALF) was determined by Wright-Giemsa staining for differential leukocyte count. The lesions in the lung tissue of rats were assessed by semi-quantitative lung injury scoring. The expression of ICAM-1 in alveolar epithelial cells was determined by immunohistochemistry and semi-quantitative analysis. The NF-κB nuclear translocation was determined by semi-quantitative analysis. Results In the positive control group and the TRALI group, the ratio of polymorphonuclear leukocytes (PMN) in the bronchoalveolar lavage fluid[ (39.6±12.5) % and (33.5±11.5) %]and the lung injury score[ (2.32±0.70) and (1.98±0.87) ] were significantly higher than those in the normal control group[ (9.8±3.5) % and (0.00±0.00) ]and the LPS control group[ (11.4±4.1) % and (1.07±0.48) ], respectively (all P<0.05) . In the positive control group and TRALI group, the expressions of ICAM-1 protein[ (0.28±0.09) and (0.24±0.07) ]and ICAM-1 mRNA [ (1.53±0.17) and (1.24±0.11) ]in the alveolar epithelial cells were significantly higher than those in the normal control group[ (0.12±0.03) and (0.36±0.05) ]and LPS control group[ (0.16±0.07) and (0.89±0.10) ], respectively (all P<0.05) . In the positive control group and TRALI group, the expression of NF-κB in the alveolar epithelial cells[ (23.8±3.20) and (27.4±4.60) ]was significantly higher than that in the normal control group (6.90±2.30) and the LPS group (11.7±2.80) , respectively (all P<0.05) . Conclusion In the lung tissues of TRALI rats, the expressions of ICAM-1 protein and ICAM-1 mRNA, and the infiltration of PMN increase. Meanwhile, the expression of NF-κB increases in rat alveolar epithelial cells, indicating that ICAM-1 may be involved in adhesion and aggregation of PMN and endothelial cells, suggesting that NF-κB activation may be involved in the regulation of TRALI inflammatory mediators and ICAM-1 gene transcription, which may play a significant role in the pathophysiology of TRALI. Key words: Acute lung injury, transfusion-related; Lung; NF-κB; Intercellular adhesion molecule