[DEK-targeting aptamer DTA-64 inhibits epithelial-mesenchymal transition of airway epithelial cells in bronchial asthmatic mice via blocking TGF-β1 signaling pathway].

Objective To investigate the inhibitory effect of DEK targeting aptamer 64 (DTA-64) on airway inflammation and epithelial to mesenchymal transition (EMT) induced by ovalbumin (OVA) in asthmatic mice. Methods Thirty-two female BALB/c mice (8 weeks old) were randomly divided into PBS group, OVA model group, DTA-64 group (1 μg/mouse), and control aptamer group, with 8 in each. HE staining of lung tissues was used to detect inflammatory cell infiltration around the airways; immunohistochemical staining was used to detect DEK expression around the airways; ELISA was used to detect serum IgE, and Th2-type cytokines IL-4, IL-5, IL-13 and Th1-type cytokine IFN-γ in bronchoalveolar lavage fluid (BALF); Western blot was applied to detect the EMT-related proteins α-SMA, Snail+Slug, vimentin, and E-cadherin, and TGF-β1/Smad, MAPK, PI3K, AKT, as well as mTOR in lung; and flow cytometry was used to observe the α-SMA expression in the lung single cell suspensions. Results DEK protein was highly expressed in the lung tissues of OVA group mice and decreased in the DTA-64 group mice; DTA-64 reduced the infiltration of eosinophils and neutrophils around the airways, down-regulated serum OVA-specific IgE and IL-4, IL-5, IL-13 in BALF, and up-regulated IFN-γ; DTA-64 also reduced the expressions of vimentin, α-SMA, Snail+Slug in the lung tissue, and up-regulated epithelial marker E-cadherin. DTA-64 inhibited the expressions of TGF-β1 and its downstream canonical pathways Smad2/3 and Smad4, as well as the phosphorylation of non-canonical TGF-β1 pathways ERK1/2, p38 MAPK, JNK and PI3K/AKT/mTOR. Conclusion DTA-64 may inhibit the airway inflammation and EMT induced by OVA in asthmatic mice via blocking TGF-β1/Smad, MAPK and PI3K signaling pathways, thereby alleviating airway remodeling in asthma.