Fig. 1

MiRNA-21a-5p overexpression promotes skin and lung fibrosis in bleomycin-induced SSc mice. The SSc murine model was induced by subcutaneously injecting 100 μg bleomycin dissolved in 100 μL PBS into 8 week-old C57BL/6 mice daily for 5 weeks. On days 14, 21, and 28 from the start of bleomycin injection, plasmid containing of 100 μg pre-miRNA-21a-5p (n = 5) or pre-miR-NC as a control (n = 5) in 1 mL saline was hydrodynamically injected into the mice. The mice were sacrificed on day 33 from the start of bleomycin injection, and histologic analysis was performed. a, b Representative images of the skin stained with hematoxylin and eosin and Masson’s trichrome (MT) a and lung b tissues of bleomycin-induced mice injected with plasmid containing of pre-miRNA-21a-5p or pre-miR-NC. The graphs show the skin dermal thickness a and pulmonary fibrosis score b. Original magnification: 100 × . Scale bar: 100 µm