Figure 3.

The effect of cecropin A on tight junction (TJ) protein expression, membrane distribution and F-actin polymerization. Western blotting analysis of zonula occludens-1 (ZO-1), occludin and claudin-1 expression were upregulated by cecropin A treatment ((A), n = 3); quantification of ZO-1, occludin, and claudin-1 protein expression was shown ((B), n = 3); cell immunofluorescence (C) (400×) showed that the cecropin A induced the TJs polymerized at the cell–cell boundary (a–f) and indicated F-actin polymerization (g,h) in cells ((c), n = 3). The results were confirmed by three independent experiments per treatment. Representative results of the three independent experiments are shown. Data (mean ± SEM) were analyzed with the Student’s t-test. Cell nuclei were stained by 4′,6-Diamidino-2-phenylindole dihydrochloride (DAPI) and are shown in blue. Claudin-1, ZO-1 and occludin are shown in red and pointed out by white arrow heads. F-actin is shown in green. Scale bar is 50 μm. *** p < 0.001.