Figure 5

Bleomycin (BLM)-induced pulmonary fibrosis was attenuated by ACE2/Ang(1–7) and exacerbated by AngII via different effects on the mir-21-mediated Spry1/ERK/NF-κB/NLRP3 pathway. Representative microphotographs of lung sections from controls and the BLM, BLM + AngII, BLM + Ang(1–7), BLM + lentiACE2, and BLM + lentiNC groups [n = 12 rats per group] stained with H&E are shown (original magnification × 200; scale bar = 100 μm). (A,B) Morphological changes in fibrotic lungs were quantified by the Ashcroft score. (C) The hydroxyproline content of lungs in the different groups. (D) The expression of mir-21 in lungs was determined by qRT-PCR. (E) In situ hybridization (ISH) staining was performed to determine the localization and expression of mir-21 (original magnification × 200; scale bar = 50 μm). (F) The protein levels of Spry1, p-ERK, NF-κB, and collagen in lung tissues were analyzed by western blot. (G,H) Immunohistochemical staining was performed to determine the localization and expression of NF-κB (G: original magnification × 400; scale bar = 50 μm) and NLRP3 (H: original magnification × 200; scale bar = 100 μm) proteins. The data are presented as means ± SD. *P < 0.05 versus control; ^# P < 0.05 versus BLM; ^† P < 0.05 versus BLM; ^‡ P < 0.05 versus BLM + lentiNC.