[Wood smoke condensate induced epithelial-mesenchymal transition in human airway epithelial cells].
OBJECTIVE
To observe the detrimental effects of wood smoke condensate (WSC) exposure on human bronchial epithelial cells (HBEC), and to explore the expression of epithelial-mesenchymal transition (EMT) markers in HBEC exposed to WSC.


METHODS
HBEC were exposed respectively to 5, 10, 20, 40 and 50 mg/L of WSC /CSC for 7 days, with control groups only in cell culture medium at the same time, then the total cytoactivity was detected by cell counting kit-8. After observing the cellular morphology of WSC-stimulated HBEC. Western blot and immunofluorescence method were used to evaluate the expression levels of type I collagen, vimentin, E-cad and MMP-9 in HBEC exposed to WSC (10 mg/L) and cigarette smoke condensate (CSC) (10 mg/L) for 7 days. Statistical evaluation of the continuous data was performed by ANOVA. Independent-Samples t-test for between-group comparisons.


RESULTS
After 7 days of exposure to WSC, HBEC manifested a morphological characteristic of loss of cell-cell contact and elongated shape. The level of E-cad was decreased in WSC exposure groups (Western blot: 0.30 ± 0.05, F = 22.07, P < 0.05) compared with the groups without WSC exposure (Western blot: 0.59 ± 0.08, F = 22.07, P < 0.05). In contrast, an upregulation in expression of type I collagen (Western blot: 0.58 ± 0.04 vs 0.26 ± 0.02, F = 119.72, P < 0.05) and MMP-9 (0.56 ± 0.08 vs 0.19 ± 0.03, F = 21.79, P < 0.05) was observed in the presence of WSC, compared with the control groups. Immunofluorescence analysis showed that after a 7-day exposure to WSC in these cells, the E-cad protein was lost whereas type I collagen, vimentin and MMP-9 were acquired. Both Western blot and immunofluorescence analysis showed no difference in expression levels of E-cad, type I collagen, vimentin and MMP-9 between WSC and CSC exposure groups.


CONCLUSIONS
WSC exposure could induce EMT-like process in human airway epithelial cells.
The State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital, Guangzhou Medical University, Guangzhou 510120, China.
Wenxi
W
Li
Weifeng
W
Zou
Bing
B
Li
The State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital, Guangzhou Medical University, Guangzhou 510120, China. Email: pxran@gzhmc.edu.cn.
Pixin
P
Ran
D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology; D012906:Smoke / Q000009:adverse effects*; D014026:Nicotiana / Q000633:toxicity; D014746:Vimentin / Q000378:metabolism; D014934:Wood
D024042:Collagen Type I; D012906:Smoke; D014746:Vimentin