Cells | COPD versus control | TGF-β1 | TGF-β R1 | TGF-β R2 | Smad 2 | Smad 3 | Smad 4 | Smad 7 |
Epi cells airways | Stage II | ▾ | ▾ | ▾ | ▾ | |||
Stage IV | ▾ | |||||||
Stroma cells | Stage II | ▾ | ▾ | ▾ | ▾ | |||
Stage IV | ||||||||
Type-2 cells | Stage II | ▾ | ▾ | |||||
Stage IV |
COPD: chronic obstructive pulmonary disease; TGF: transforming growth factor; epi: epithelial; Stage II: Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II COPD; Stage IV: GOLD stage IV COPD. ▾: indicates a significantly lower expression in the stage II or stage IV group compared with the control group. No significant upregulations were observed.