Fluorescence Microscopy

Lung tissues sections were fixed in 4% paraformaldehyde (30 minutes), recovered with antigen retrieval buffer (20 minutes), permeabilized with 0.3% Triton X‐100 (10 minutes), and blocked with 5% bovine serum albumin (30 minutes at room temperature). Primary antibody GFP (1:50; Santa Cruz Biotechnology, Paso Robles, CA) was added and incubated overnight at 4°C. Then Alexa Fluor 488‐labeled secondary antibodies (1:500; Abcam Incorporated, Cambridge, UK) were added and incubated 50 minutes in dark. After washed 3 times, the sections were stained with DAPI for 10 minutes and visualized using a fluorescence microscope (Olympus).