Abstract
In the present study, the regulatory effect of cytokine-induced neutrophil chemoattractant (CINC) and epithelial neutrophil-activating peptide 78 (ENA-78) on pulmonary neutrophil (PMN) accumulation in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mice, and the therapeutic effect of pyrrolidine dithiocarbamate (PDTC), was investigated. BALB/c mice were divided into control, LPS and PDTC + LPS groups using a random number table. The phosphorylation of nuclear factor-κB (NF-κB) was detected using a western blot, and the mRNA expression levels of CINC were evaluated using reverse transcription-quantitative polymerase chain reaction. The expression of NF-κB, CINC and ENA-78 was detected using immunohistochemistry. The production of interleukin (IL)-8 and IL-10 in serum and broncho-alveolar lavage fluid (BALF) was analyzed using an enzyme-linked immunosorbent assay. The total number of leukocytes and proportion of PMNs in BALF was also determined. Following injection with LPS (20 mg/kg), the expression levels of p-NF-κB, CINC and ENA-78 were increased in lung tissue, and the expression levels of IL-8, IL-10 and the number of PMNs increased in serum and BALF. However, in comparison with the LPS group, the degree of lung injury was reduced in ARDS mice that were treated with PDTC. In addition, the expression level of p-NF-κB and the production of chemokines in lung tissue decreased in ARDS mice that were treated with PDTC, and the number of PMNs in BALF also decreased. In conclusion, the results of the present study suggest that the LPS-induced phosphorylation of NF-κB may result in the synthesis and release of CINC and ENA-78, which induce the accumulation of PMNs in the lung. Therefore, PDTC may be used to reduce the production of chemokines and cytokines, thereby decreasing the activation of PMNs in lung tissue and reducing the damage of lung tissue in ARDS.