Idiopathic Pulmonary Fibrosis: Aberrant Recapitulation of Developmental Programs? (original) (raw)
Figure 1
Schematic Overview of the Epithelial–Mesenchymal Transition as Modulated by TGF-β and BMPs
In IPF lungs, TGF-β3, gremlin, and LEF-1 are up-regulated, while BMP-2 is down-regulated. Dysregulation of TGF-β/BMP pathway induces a fibrotic phenotype. EMT, so important in development, is likely to represent one possible response of the alveolar epithelial cell facing sustained injury. Increased expression of BMPs may not only antagonize TGF-β-induced EMT, enhancing re-epithelialization, but also may cause the opposite process, mesenchymal-to-epithelial transition (MET).