High FFA-induced proliferation and apoptosis in human umbilical vein endothelial cell partly through Wnt/beta-catenin signal pathway.

Free fatty acids (FFA)-induced proliferation and apoptosis was studied in human umbilical vein endothelial cells (HUVECs). A recombinant adenovirus containing a RNAi cassette targeting the GSK-3beta gene was produced and its silencing effect on GSK-3beta gene was detected by Western blot analysis and immunohistochemistry assay in HUVECs. The effect of the RNAi on the protein level of beta-catenin was explored by transfecting the RNAi adenovirus to inhibit the expression of GSK-3beta protein. The subsequent effect on the Wnt/GSK-3beta/beta-catenin signal pathway and on proliferation and apoptosis of HUVECs cultured with FFAs, was analyzed by BrdU assay, Annexin V-FITC/PI Apoptosis Detection Kit, and 4',6-diamidino-2- phenylindole(DAPI) to explore the possible connection between the signaling pathway and FFA-induced proliferation and apoptosis. The Western blot results showed that the expression of GSK-3beta protein in HUVECs could be inhibited efficiently by the RNAi adenovirus, and that the protein level of beta-catenin was increased by RNAi adenovirus transfection. The results of the BrdU assay suggested that knockdown of GSK-3beta with the RNAi adenovirus may stimulate the proliferation of HUVECs. Apoptosis was observed in HUVECs exposed to FFAs (0.75 mmol/L) for 72 h, and this effect could be partly reversed when interfering with the RNAi adenovirus. It may be concluded that the RNAi adenovirus specific to GSK-3beta may partly protect HUVECs from apoptosis induced by FFAs, probably through the up-regulation of the Wnt/beta-catenin signal pathway.