Fig. 1

FSTL1 was highly expressed in COPD patients and correlated with autophagy. a FSTL1 level was significantly higher in the serum of COPD patients (n = 28) compared with control (n = 25) (ELISA). b Airway specimens of COPD showed inflammation infiltration, RBM fragmentation (black triangle), epithelial integrity loss, and cilia lodging (black arrow) (HE staining, ×400). c Positive areas of FSTL1 in airway specimens of COPD patients were significantly larger than those of control subjects (immunohistochemistry staining, ×400). d Positive areas of LC3B in airway specimens were significantly larger than control subjects (immunohistochemistry staining, ×400). e Quantification of IHC. Median of each group is presented. * difference between control and COPD group, p < 0.05; ***p < 0.001, t-test. Scale bar, 20 μm. Abbreviations: CON, control