[Inhibition of M2 macrophage polarization and reduction of airway inflammation in asthmatic mice with lncRNA MRAK088388 knockout].

Objective To investigate the long non-coding RNA(lncRNA) MRAK08838 regulates macrophage function to influence the development of asthmatic airway inflammation. Methods MRAK088388 gene knockout (MRAK088388) mouse model was prepared and allergic asthma was induced by dust mite protein Dermatophagoides farinae 1 (Der f1). The mice were sacrificed after 28 days of modeling, and serum was collected to measure IgE and IgG. The FinePointe RC system was used to measure airway hyperresponsiveness and evaluate lung function in mice. Lung tissue was taken for HE staining, and periodic acid-Schiff (PAS) staining was used to evaluate inflammatory infiltration and mucus secretion in mouse lungs. Fluorescence quantitative PCR was used to detect the expression level of lncRNA MRAK08838 in bronchoalveolar lavage fluid (BALF) cells and lung tissue of asthmatic mice. ELISA was used to detect the levels of inflammatory cytokines IFN-γ, IL-4, IL-5, IL-13, IL-10 and IL-17A. Flow cytometry was used to evaluate the phenotype of macrophages in BALF and lung tissue, as well as the proportion of neutrophils, eosinophils, and alveolar macrophages. The changes of the above indicators were detected in mice by adoptive transfer of bone marrow-derived macrophages (BMDM). Results Under the challengle of Der f1, MRAK088388 mice showed reduced allergic airway inflammation, including reduced eosinophils in BALF and reduced production of IgE and IgG1. In addition, Der f1-treated MRAK088388 mice had fewer M2 macrophages than wild-type asthmatic mice. Wild-type mouse BMDM (M0) and Der f1-treated MRAK088388 mice also showed mild inflammatory response. Conclusion Knockout of MRAK088388 alleviates airway inflammation in asthmatic mice by inhibiting M2 polarization of airway macrophages.