Fig. 1

Single-walled carbon nanotubes (SWCNTs) induced pulmonary fibrosis and senescence of AECIIs in mouse lung tissues. Mice were exposed to 40 μg SWCNT by intratracheal instillation, then lung tissues were collected on days 3, 7 and 28. A Scheme of workflow for evaluation of cellular senescence and pulmonary fibrosis induced by SWCNTs in vivo. B–D Western Blotting analysis of p21 and p16 protein expressions (n = 3) in lung tissues. Contents of TGF-β (E) and PAI-1 (F) in bronchoalveolar lavage fluid (BALF) quantified by ELISA (n = 5). HE staining (G) and Masson’s trichrome staining (H) of mouse lung tissues (200×). I The semiquantitative Ashcroft scores for the severity of pulmonary fibrosis (n = 4). J The hydroxyproline (HYP) level (n = 4) in lung tissues of mice. K Immunohistochemistry (IHC) of COL I expression (n = 5) in lung tissues of mice. L, M The correlation of hydroxyproline contents in mice lung tissues and senescence-associated secretory phenotype (SASP) factors (TGF-β and PAI-1) in BALF. N Immunostaining for p16 (a senescence-related marker) and SP-C (an AECIIs marker) from SWCNTs-exposed lung tissues of mice on day 28 was detected by immunofluorescence (IF) (400×). *P < 0.05 vs CTRL group