title: Antiangiogenic effect of rosiglitazone is mediated via peroxisome proliferator-activated receptor gamma-activated maxi-K channel opening in human umbilical vein endothelial cells.
abstract: Recent evidence shows that peroxisome proliferator-activated receptor gamma (PPARgamma) ligands induce the antiangiogenic effect in endothelial cells and tumors. In the present study, we elucidated the involvement of maxi-K channel activation in the antiangiogenic effect of rosiglitazone, a well known PPARgamma ligand in human umbilical vein endothelial cells. We found that the antiangiogenic effects of rosiglitazone were reversed by either bisphenol A diaglycidyl ether, a PPARgamma antagonist, or iberiotoxin, a maxi-K channel blocker. Knockdown of maxi-K channel expression also reversed the antiangiogenic effects. Iberiotoxin reversed the rosiglitazone-induced hyperpolarization while having no effect on the endogenous PPARgamma activation, suggesting that rosiglitazone activates maxi-K channel via PPARgamma. In the rosiglitazone-induced antiangiogenic process, endothelial nitric-oxide synthase-Ser1179 phosphorylation and NO production were significantly elevated, and treatment with the NOS inhibitor N(G)-monomethyl-L-arginine acetate abolished the antiangiogenic and apoptotic effects of rosiglitazone, indicating NO as a key mediator of the rosiglitazone actions. In conclusion, rosiglitazone significantly inhibited VEGF165-induced angiogenesis by a proapoptotic mechanism via PPARgamma-mediated NO production, followed by maxi-K channel opening.
authors.affiliation: Medicinal Science Division, Korea Research Institute of Chemical Technology, P. O. Box 107, Yuseong-gu, Daejeon 305-600, Korea.
authors.forename: Ki Young
authors.initials: KY
authors.lastname: Kim
authors.affiliation: Medicinal Science Division, Korea Research Institute of Chemical Technology, P. O. Box 107, Yuseong-gu, Daejeon 305-600, Korea. Electronic address: hgcheon@krict.re.kr.
authors.forename: Hyae Gyeong
authors.initials: HG
authors.lastname: Cheon
mesh_terms: D001562:Benzimidazoles / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D047495:PPAR gamma / Q000378:metabolism*; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001562:Benzimidazoles; D051036:Large-Conductance Calcium-Activated Potassium Channels; D047495:PPAR gamma; D045162:Thiazolidinediones; D014665:Vasodilator Agents; D000077154:Rosiglitazone; C086491:NS 1619