Figure 4

Overexpression of KLF4 attenuated TGF-β1-induced EMT of alveolar epithelial cells. (A) KLF4 mRNA level expression in AECs^(a) and lung tissues from mice^(b) was assessed with PCR. Immunocytochemistry was performed using a primary antibody against KLF4 to show the expression of KLF4 in AECs^(c) and lung tissue of mice^(d). Scale bar = 50 μm for (A). (B) AECs were co-infected with AdKLF4 and AdtTA (20 MOI) and maintained in the medium with or without tetracycline (Tc; 0.1 μg/mL). Nuclear protein lysates were immunoblotted with antibodies against KLF4 or Histone as an internal control. (C) F-actin staining was performed to show the morphological changes in AECs upon TGF-β1 stimulation. (D) AECs were co-infected with AdKLF4 and AdtTA in the medium with or without tetracycline and then treated with or without TGF-β1 (5 ng/mL) for 48 hours.The TGF-β1-stimulated morphological change in AECs with or without overexpression of KLF4 was observed under phase contrast light microscopy. (E) Total proteins were immunoblotted with antibodies against E-cadherin and fibronectin. β-actin was used as a loading control. Data shown are representative of three independent experiments. (F) Immunochemistry staining of E-cadherin and fibronectin in TGF-β1-induced EMT in AECs with and without overexpression of KLF4. (G) Cells were fixe F-actin staining (Green) was shown. Nuclei were counterstained with DAPI (Blue). ((A) Scale bar = 50 μm. (B) Scale bar = 20 μm). Data shown are representative of three independent experiments.