Fig. 1

HE stain and Masson stain results of skin and lung tissues in mice (×200). a–d, i–l HE stain; e–h, m–p Masson stain, a–h Skin tissues, i–p Lung tissues. a, e; i, m In the control group, the skin tissues had proper thickness and clear structure; the lung tissues indicated that the alveoli of mice were transparent and bright, the structure was intact. b, f; j, n In the 7-day Model group, the skin tissues showed little thickening and the inflammatory cell infiltration was the most pronounced; the inflammatory cell infiltration was more evident. c, g; k, o In the 28-day Model group, skin samples from the systemic sclerosis mice showed significant thickening; the lung tissues increased collagen deposition, and thickening of alveolar septa. d, h; l, p. In the 42-day Model group, the collagen deposition and skin fibrosis were pronounced; alveolar collapse, collagen deposition, and pulmonary parenchymal fibrosis evident