[Effects of interleukin-11 antagonist on pulmonary fibrosis in mice].

Objective: To investigate the effects of interleukin 11 (IL-11) antagonist on bleomycin (BLM)-induced pulmonary fibrosis in mice. Methods: C57BL/6 mice were randomly divided into the control group, IL-11 antagonist group, BLM group, and BLM + IL-11 antagonist group (30 in each group). Mice in the BLM group and BLM + IL-11 antagonist group were injected with BLM at the dose of 1.5 mg/kg to induce pulmonary fibrosis. The IL-11 antagonist IL-11 Rα FC (2.5 mg/kg) was administered via the tail vein to the mice in the IL-11 antagonist group and BLM + IL-11 antagonist group every 3 days from the BLM injection. The survival status of the mice was observed. On the 21^st day after modeling, HE staining, Masson staining, and Ashcroft score were used to evaluate the degree of pulmonary fibrosis. The content of hydroxyproline (HYP) in lung tissue was determined by the alkaline hydrolysis method. The gene and protein expressions of Collagen I, Collagen III, and α-SMA in lung tissues were detected by real-time PCR and Western blot, respectively. TGF-β1 content in lung tissue was determined by enzyme-linked immunosorbent assay. Results: Compared with the control group, BLM reduced the survival rate, destructed the lung tissue, and increased the gene and protein expressions of Collagen I, Collagen III, α-SMA, and the content of TGF-β1 in lung tissue. While, IL-11 Rα Fc treatment improved the survival rate of BLM-induced pulmonary mice, reduced pathological changes, and hydroxyproline content in lung tissue. IL-11 Rα Fc also reduced Collagen I, Collagen III, and α-SMA mRNA and protein expression in the lungs of BLM-treated mice, as well as TGF-β1 content. Conclusion: The IL-11 antagonist alleviates BLM-induced pulmonary fibrosis in mice, which provides a new idea for the clinical treatment of pulmonary fibrosis.