Abstract:Objective To investigate the protective effect of interleukin-1 receptor antagonist (IL-1RA) on airway inflammation and airway remodeling in rats with chronic obstructive pulmonary disease (COPD). Methods Thirty Wistar rats were induced by smoking and intratracheal injection of lipopolysaccharide (LPS). They were divided into control group, methylprednisolone treatment group and IL-1RA treatment group according to random number table method, with 10 rats in each group. Rats in each group were continuously intervened for 20 days starting on the 20th day. The control group was injected with 0.5 mg/(kg·d) saline, the methylprednisolone treatment group was injected with 0.5 mg/(kg·d) methylprednisolone, and the IL-1RA treatment group was subcutaneously injected with IL-lRA l00 pg per rat. The appearance of rats in each group was observed, blood gas was measured, lung histopathological examination was carried out, and mean alveolar number (MAN) and mean lining interval (MLI) were calculated. The content of High mobility group protein B1 (HMGB1) in bronchoalveolar lavage fluid (BALF) of rats in each group was detected by enzyme-linked immunosorbent assay, and the expression of HMGB1 in lung tissue of rats in each group was detected by Western blot. Results After treatment, there were significant differences in MAN and MLI among the three groups (P < 0.05). MAN in IL-1RA group was higher than that in methylprednisolone group and control group (P < 0.05), and MLI in IL-1RA group was significantly lower than that in methylprednisolone group and control group (P < 0.05). The expression of HMGB1 in BALF and lung tissue of three groups was significantly different (P < 0.05). The expression of HMGB1 in BALF of IL-1RA group was lower than that of methylprednisolone group and control group (P < 0.05), and the expression of HMGB1 in lung tissue was lower than that of methylprednisolone group and control group (P < 0.05). Conclusion IL-RA can reduce the expression of HMGB1 in lung tissue and alveoli of COPD rats, reduce airway inflammation, improve blood gas function and protect airway remodeling.