Abstract:

Objective To explore the signaling pathway and molecular mechanism involved in up⁃regulation of MUC5AC in 16HBE cells induced by CSE using the method of transcriptome sequencing，and to provide theoreti⁃ cal basis for finding new targets of COPD. Methods Differently expressed genes（DEGs）were detected by tran⁃ scriptome sequencing in 16HBE cells induced by CSE. Excavating out which potential signal pathway involved in up⁃ regulation of MUC5AC in 16HBE cells induced by CSE was excavated through bioinformatics analysis. The transcript levels of relevant genes in the screened signaling pathways were verified by RT ⁃ qPCR，and whether the signaling pathway and related genes were involved in up⁃regulation of MUC5AC in 16HBE cells induced by CSE was verified using the method of signaling pathway agonists and siRNA interference. Results A total of 2 567 DEGs were detected by transcriptome sequencing，and the bioinformatics analysis showed that MAPK signaling，WNT signaling， and PI3K⁃Akt in 16HBE cells were abnormally expressed after CSE stimulation. RT⁃qPCR showed that the tran⁃ script levels of WNT4，WNT5B，WNT6 and WNT10A genes were down⁃regulated when compared with control group （0.885 times，0.893 times，0.705 times，0.618 times，P < 0.05），and WNT9A were up ⁃ regulated（3.727 times， P < 0.05），which were consistent with transcriptome sequencing. After the activation of the classical WNT signaling pathway，the MUC5AC transcript level of 16HBE cells was up⁃regulated by 3.197 times when compared with the control group（P = 0.031 3）. However，in the small molecule interference experiment，the transcript level of MUC5AC in WNT5B siRNA + CSE group was 2.092 times higher than that in negative control + CSE group（P = 0.016 2）. Conclusion WNT5B in the non ⁃classical WNT signaling pathway is down ⁃ regulated and participates in CSE induced up⁃regulation of MUC5AC in 16HBE cells. 

Key words:

COPD, CSE, 16HBE, mucus hypersecretion, WNT signaling pathway, transcrip? tome sequencing