Figure 1.

Characterization of rat alveolar type I-like cells. Rat alveolar type I–like cells were cultured as described in Materials and Methods. (A) Sections from paraffin-embedded cells were stained with hematoxylin and eosin. (B) Immunofluorescence detection of T1α in type I–like cells cultured on matrix-coated inserts was done after cell fixation in 4% paraformaldehyde. (C) Western blot analysis for T1α protein in rat alveolar epithelial cells cultured on different culture conditions for 6 d. Lane 1: Cells cultured on tissue culture plastic in 5% FBS supplemented-DMEM. Lane 2: Cells cultured on insert coated with 0.4 ml of a 4:1(vol/vol) mixture of rat tail collagen and Matrigel in 5% FBS-supplemented media. dex (10⁻⁸ M) was added for last 4 d of culture (type I–like cell phenotype). Lane 3: Cells cultured on insert coated with a mixture of rat-tail collagen and Matrigel in media supplemented with 5% RS, 10 ng/ml KGF, and 10⁻⁸ M dex (type II cell phenotype). The results are representative of three independent experiments.