Apolipoprotein A1 Inhibits TGF-β1-Induced Epithelial-to-Mesenchymal Transition of Alveolar Epithelial Cells

Background Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterized by the accumulation of excessive fibroblasts and myofibroblasts in the extracellular matrix. The transforming growth factor β1 (TGF-β1)–induced epithelial-to-mesenchymal transition (EMT) is thought to be a possible source of fibroblasts/myofibroblasts in IPF lungs. We have previously reported that apolipoprotein A1 (ApoA1) has anti-fibrotic activity in experimental lung fibrosis. In this study, we determine whether ApoA1 modulates TGF-β1–induced EMT in experimental lung fibrosis and clarify its mechanism of action.