Fig. 2

Piezo1 induced type II pneumocytes apoptosis in ARDS. a Oxygenation index was calculated as PaO2/FiO2, OI was less than 300 in ARDS as defined by Berlin definition. Wet/dry ratio was significantly increased in ARDS rat. Lung morphometry assessed by HE staining in different groups (100X/400X magnification) edema, hemorrhage and alveolar wall thickness were observed in the image of ARDS group accompanied by inflammatory cells infiltration .b Immunofluorescence staining of Piezo1and SP-A. Piezo1 and SP-A double positive cells stained in orange.(100X magnification) c Apoptosis of type II pneumocytes in control and ARDS mice, analyzed by annexin V-fluorescein isothiocyanate/PI double staining. Cells in the B2 and B4 quadrants(annexin V+/PI+ and annexin V+/PI-, respectively) were considered to be apoptotic. Graphical representation shows significant difference. d. Apoptosis of A549 cells treated with stretch and/or siRNA, analyzed by annexin V-fluorescein isothiocyanate/PI double staining. Graphical representation shows significant difference. e Western blot of Piezo1, caspase 3 and Bcl-2 in different group. Stretch represents A549 under stretch, control siRNA + stretch represents A549 transfected with control siRNA and was applied stretch.Piezo1 siRNA + stretch represents knock down of Piezo1 in A549 and applied stretch. Cleaved caspase 3 was the activated form of caspase. GAPDH was used as internal reference. f The relative protein expression levels of cleaved caspase3/caspase3,Bcl-2 and Piezo1