Anti-angiogenic action of PPARγ ligand in human umbilical vein endothelial cells is mediated by PTEN upregulation and VEGFR-2 downregulation.

Peroxisome proliferator-activated receptor γ (PPARγ) activation has anti-angiogenic and apoptotic effects in endothelial cells. Here, we investigated the mechanisms of the anti-angiogenic action of a novel PPARγ ligand, KR-62980. KR-62980 inhibited in vitro basal tube formation and in vivo neovascularization in mice induced by Matrigel containing vascular endothelial growth factor (VEGF(165), 5 ng/ml). VEGF(165)-induced cell proliferation and chemotactic migration in human umbilical vein endothelial cells (HUVECs) were also suppressed by KR-62980, in a mechanism accompanied by apoptotic cell death. KR-62980 downregulated the VEGF(165)-induced VEGFR-2 expression but increased the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression in parallel with reduced phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2), PI3K p85α, and p38 MAPK. The knockdown of PTEN expression abolished KR-62980-suppressed cell proliferation and angiogenesis. All of the effects of KR-62980 disappeared with pretreatment of bisphenol A diaglycidyl ether (BADGE), a PPARγ antagonist. In summary, KR-62980 inhibited VEGF(165)-induced angiogenesis in HUVECs by PPARγ-mediated dual mechanisms: VEGFR-2 downregulation and PTEN upregulation.