Fig. 2

Hyperoxia caused AECII apoptosis and ubiquitin proteasome pathway changed. A After 24, 48 and 72 h hyperoxia exposure, AECII apoptosis was analyzed by Annexin V-FITC/PI double staining followed by flow cytometry. B The expression of ubiquitinated proteins were detected by Western blot assays in different groups and the grouping of gels cropped from the same gel. β-actin was used as the loading control. The part of original data were presented in Additional file 1: Fig. S2. C Reagent kit with specific fluorescent substrate was utilized to measure the activity of 20 s proteasome. Values represent mean ± SD; ** P < 0.05 versus normoxia group