Effects of honokiol on ER structure, SHP-1 activity, and VEGF generation.

<p>(A) Cells were treated with honokiol (HUVECs, 10 µM; SCM-1, 40 µM) for 18 h. Cells were collected and visualized by electron microscopy as described in “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043711#s4" target="_blank">Materials and Methods</a>”. Arrows indicate dilated ER. Original magnification: 9800x. (B) Cells were treated with or without honokiol (HUVECs, 20 µM; AGS, 20 µM) in the presence or absence of recombinant protein of calpain II (re-calpain) or calpain II siRNA transfection, and then cells were analyzed for SHP-1 activity. (C) Cells were transfected with wild type STAT-3 (wt) and mutant STAT-3 (mut) plasmids or SHP-1 siRNA, and then the VEGF generation was determined. (D) Interaction of calpain and SHP-1 was detected in AGS cells. Immunoprecipitated proteins were collected and subjected to SDS-PAGE and immunoblotting with anti-calpain-II or anti-SHP-1 antibodies. In A and D, results shown are representative of at least 4 independent experiments. In B and C, data are presented as mean ± SEM (n≥4). *P<0.05 as compared with control. #P<0.05 as compared with honokiol alone.