Bleomycin-induced mouse pulmonary fibrosis model

Male C57BL/6 mice (6–7 weeks old) were purchased from the Medical School of Yangzhou University (Yangzhou, China). All mice were maintained under standard conditions with free access to water and laboratory rodent food. For the evaluation of the effect of miR-877-3p on bleomycin-induced pulmonary fibrosis, mice were anesthetized with pentobarbital sodium (3 mg/kg). Next, mice received a single, slow intratracheal injection of 2 × 10⁸ TU LV-negative control (NC) or LV-miR-877-3p with MicroSprayer (Penn-Century, Wyndmoor, PA). The GFP was insert in the LV-vector. Three days later, mice received 5 mg/kg bleomycin (Nippon Kayaku Co., Tokyo, Japan) dissolved in 50 μl of saline on day 0. Control mice received 50 μl of saline instead. Mice were sacrificed on days 14. Mouse lungs were obtained for the analysis of histopathology, collagen content, Q-PCR and western blotting.