Quantitative PCR
Total messenger RNA (mRNA) was extracted from lung tissues using TRIzol regent (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s instructions and then reverse transcribed into complementary DNA (cDNA) using the TIANGEN kit (KR 103, TIANGEN Biotechnology, Beijing, China). An SYBR Green I Q-PCR kit (TransGen Biotech, Beijing, China) was used to amplify PCR by the Bio-Rad IQ5 system (Bio Rad, Hercules, CA, USA ). A fluorescence reporter signal was detected based on the internal reference dye signal for β -actin to normalize for non-PCR associated fluorescence fluctuations between microwells. Supplementary Table 1 lists the primer sequences used in our experiments. All primers were synthesized by Beijing Tianyihuiyuan Biotechnology Company.