Endoplasmic Reticulum Stress Induces MUC5AC and MUC5B Expression in Human Nasal Airway Epithelial Cells
- Author:
Min Han KIM
1
;
Chang Hoon BAE
;
Yoon Seok CHOI
;
Hyung Gyun NA
;
Si Youn SONG
;
Yong Dae KIM
Author Information
- Publication Type:Original Article
- Keywords: Endoplasmic Reticulum Stress; X-Box Binding Protein 1; Transcription Factor CHOP; Activating Transcription Factor 6; Mucins
- MeSH: Activating Transcription Factor 6; Carrier Proteins; CCAAT-Enhancer-Binding Proteins; Endoplasmic Reticulum Stress; Endoplasmic Reticulum; Epithelial Cells; Glycoproteins; Humans; Immunoenzyme Techniques; Inositol; Mucins; Phosphotransferases; Real-Time Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Transcription Factor CHOP; Transcription Factors; Transfection; Tunicamycin
- From:Clinical and Experimental Otorhinolaryngology 2019;12(2):181-189
- CountryRepublic of Korea
- Language:English
- Abstract: OBJECTIVES: Endoplasmic reticulum (ER) stress is known to be associated with inflammatory airway diseases, and three major transmembrane receptors: double-stranded RNA-activated protein kinase-like ER kinase, inositol requiring enzyme 1, and activating transcription factor 6 (ATF6) play important roles in ER stress-related proinflammatory signaling. However, the effects of ER stress and these three major signaling pathways on the regulation of the production of airway mucins in human nasal airway epithelial cells have not been elucidated. METHODS: In primary human nasal epithelial cells, the effect of tunicamycin (an ER stress inducer) and 4-phenylbutyric acid (4-PBA, ER stress inhibitor) on the expression of MUC5AC and MUC5B was investigated by reverse transcriptasepolymerase chain reaction, real-time polymerase chain reaction, enzyme immunoassay, and immunoblot analysis. Small interfering RNA (siRNA) transfection was used to identify the mechanisms involved. RESULTS: Tunicamycin increased the expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules, including spliced X-box binding protein 1 (XBP-1), transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP), and ATF6. In addition, 4-PBA attenuated the tunicamycin-induced expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules. Furthermore, siRNA knockdowns of XBP-1, CHOP, and ATF6 blocked the tunicamycin-induced mRNA expressions and glycoprotein productions of MUC5AC and MUC5B. CONCLUSION.: These results demonstrate that ER stress plays an important role in the regulation of MUC5AC and MUC5B via the activations of XBP-1, CHOP, and ATF6 in human nasal airway epithelial cells.
