Rapid loss of the alveolar epithelial cell phenotype during primary culture in a matrix-independent fashion

Rationale: The alveolar epithelium is mainly composed of two cell types, alveolar epithelial type I (ATI) and alveolar epithelial type II (ATII) cells. In vitro, defining the ATI and ATII phenotype remains difficult, although primary ATII cells have been proposed to (de)differentiate into ATI-like cells over time. Methods and Results: We analyzed protein expression profiles of primary mouse alveolar epithelial cells (AEC) cultured in the presence/absence of fibronectin (FN) over time (comparing freshly isolated AEC with those cultured for 1, 3, or 5 days), using 2D-gel electrophoresis and mass spectrometry. Seve…