Western Blot Analysis of Tight Junction Proteins

Western blotting was performed in accordance with standard procedures, as described previously [2 (link)]. Anti-occludin, anti-zonula occludens-1 (ZO-1), anti-Nrf2, anti-NQO1, and anti-Keap1 (Santa Cruz Biotechnology, Inc.) antibodies and secondary antibody (1 : 2000; Millipore) were used to detect targeted protein expression. Anti-β-actin antibody (Proteintech) was used at 1 : 5000. Images were acquired by a Tanon 5500 imaging system (Tanon, Shanghai). ImageJ software was used to quantitate the staining intensity in the images, and the data were normalized to the sham or control values.