by treatment with cell dissociation buffer (Gibco, Grand Island, NY, USA) for 30
min at 37°C. Cells were passed through a 70 μm cell strainer and
incubated with following primary antibodies for 1 hr at 4°C: NKX2.1
(Abcam), carboxypeptidase M (CPM), epithelial cell adhesion molecule (EPCAM,
Santa Cruz, Dallas, TX, USA), Surfactant protein B (SFTPB, EMD Millipore,
Burlington, MA, USA), SFTPC (Abcam), T1α and aquaporin 5 (AQP5). Dead
cells were excluded by 7-aminoactinomycin D (BD Pharmingen, San Diego, CA, USA)
staining. Frequencies of AEC markers were measured using a FACSCantoTM II flow
cytometer (BD Bioscience), and acquired data were analyzed with FlowJo software
(Tree Star, Ashland, OR, USA).