ヒト血管内皮細胞におけるカルシニューリンを介した情報伝達系 : 免疫抑制剤FK506は一酸化窒素合成酵素のリン酸化を促進する

概要

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FK506 and cyclosporin A (CsA) are major immunosuppressants that function with FK-binding protein (FKBP) and cyclophillin by inhibiting calcineurin (CN) thereby modulating transcriptional regulation in T cells. FK506 has been reported to enhance phosphorylation of neural constitutive nitric oxide synthase (NcNOS). In this study, we investigated whether FK506 can inhibit CN activity as well as regulate phosphorylation of endothelial constitutive NOS (EcNOS) in human endothelial cells. Human umbilical vein endothelial cells (HUVECs) were incubated with [^<32>P] orthophosphate and treated with the addition of 12-O-tetradecanoylphorbol 13-acetate (TPA), CN, or FK506. After treatment, immunoprecipitated EcNOS was resolved using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and the phosphorylation level was quantified. EcNOS showed a substantial increase in phosphorylation with TPA. The addition of CN significantly reduced TPA-induced phosphorylation whereas the addition of FK506 significantly enhanced it. We also found TPA reduced nitrite accumulation and FK506 further inhibited NO production. In conclusion, FK506 was found to block CN-dependent dephosphorylation of EcNOS as well as inhibit NO production in human endothelial cells.
東京女子医科大学の論文
1996-10-25