IL-11 neutralizing antibodies alleviate pulmonary fibrosis in aging mice by inhibiting TGF-β/NOX4/IL-11 signaling pathway.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic interstitial lung disease mainly occurs in the elderly, presents limited therapeutic options and necessitating the development of novel drugs. Interleukin-11 (IL-11) belongs to the interleukin-6 (IL-6) family and plays a wide role in fields such as hematopoiesis, immune regulation and tumorigenesis. Recent studies have shown that IL-11 could serve as a potential target for the treatment of IPF and plays a certain role in the aging process. In this study we aims to evaluate the role and mechanism of targeted IL-11 in aging-related pulmonary fibrosis. Firstly, neutralizing antibodies targeting IL-11 were obtained through evaluation and combination of two antibodies with different epitopes can effectively alleviate pulmonary fibrosis in vivo and in vitro. Subsequently, we established pulmonary fibrosis model in aging mice and found that IL-11 was highly expressed in the serum, lung tissues and fibroblasts of fibrotic aging mice. The overexpression or functional loss of IL-11 could significantly change the profibrotic phenotype of senescent lung fibroblasts, and IL-11 neutralizing antibodies could effectively alleviate early and late pulmonary fibrosis in aging mice. Further mechanism studies have confirmed the importance of the TGF-β1/NOX4/IL-11 signaling pathway in regulating the senescence phenotype of lung fibroblasts and aging-related pulmonary fibrosis. In summary, this study elucidate the correlation between IL and 11 and pulmonary fibrosis in aging mice. Both in vitro and in vivo experiments have validated the therapeutic efficacy and molecular mechanisms of IL-11-neutralizing antibodies in pulmonary fibrosis, offering promising insights for future anti-fibrotic drug development. Abbreviations: IL-11, Interleukin-11; IPF, Idiopathic pulmonary fibrosis; TGF-β, Transforming growth factor-β; NOX4, NADPH oxidase-4; SASP, Senescence-associated secretory phenotype; ECM, Extracellular matrix; α-SMA, α-smooth muscle actin; STAT3, Signal transducer and activator of transcription 3; ERK, Extracellular regulated protein kinases; AKT, Protein kinase B; BLM, Bleomycin; WT, Wild-type; KO, Knockout; qRT-PCR, Quantitative real-time polymerase chain reaction; WB, Western blot; hAb, Humanized antibody; mAb, Monoclonal antibody; FVC, Forced vital capacity; CTGF, Connective tissue growth factor; PDGFR-α, Platelet-derived growth factor receptor-α; TNF-α, Tumor necrosis factor-α; Nrf2, NFE2-related factor 2; EMT, Epithelial-mesenchymal transition; HE, Hematoxylin and eosin; PVDF, Polyvinylidene fluoride; GAPDH, Glyceraldehyde-3-phosphate dehydrogenase; siRNA, Small interfering RNA; IL-6, Interleukin-6; MEK, Mitogen-Activated Protein Kinase Kinase; TIME, TGF-β1/IL-11/MEK/ERK; HRP, Horseradish Peroxidase; MLG, Mouse lung fibroblast cell line MLg; NCBI, National Center for Biotechnology Information; Bcl2, BCL2 apoptosis regulator; Bax, BCL2 Associated X, apoptosis regulator; MSC, Mesenchymal Stem Cell; RSK, p90 Ribosomal S6 Kinase; KD, Dissociation Constant; Nin, Nintedanib; CTL, Control; Eto, Etoposide; SA-β-Gal, Senescence-Associated β-Galactosidase.