Figure 6.

CD166^pos lung epithelial cells (LECs) were responsible for the repair of acute lung injury. (a) Kaplan–Meier curve showing survival rates of mice transplanted with phosphate-buffered saline (PBS), CD166^pos or CD166^neg LECs derived from human embryonic stem (hES) over a 3 weeks period after bleomycin-induced lung injury. The experiment was performed twice with eight mice in each of the experimental groups. The survival analysis was performed using Kaplan–Meier estimator. The P values between the experimental groups are as shown. (b) Immunocytochemistry of lung section from surviving mice transplanted with CD166^pos LECs. Top left panel represents control lung section obtained from surviving mice that were treated with bleomycin, but without cellular transplantation. For mice that were transplanted with CD166^pos LECs, the cells were present at the terminal bronchioles and appeared as clusters in the alveolar regions of damaged areas. Some of the green fluorescent protein (GFP)-positive cells were shown to be positive for SPC, a specific marker for type II pneumocyte (white arrow). Clusters of GFP^pos CD166^pos LECs eventually spread out to form new alveoli. Cell nuclei (blue) were stained with 4, 6-diamindino-2-phenylindole (DAPI). Sections were scanned with a high-resolution MIRAX MIDI system (Carl Zeiss) equipped with both bright field and fluorescence illumination. Images were then analyzed by the software Miraxviewer. Bar = 50 µm. (c) Measurement of lung pulmonary functions was performed by whole body plethysmography of mice transplanted with PBS, CD166^pos or CD166^neg lung epithelial cells (LECs). The breathing rates and tidal volumes of the three groups of mice were monitored over a 3 weeks period. Error bars represent standard deviation obtained from surviving mice at each time point.