Cilostazol inhibits cytokine-induced nuclear factor-kappaB activation via AMP-activated protein kinase activation in vascular endothelial cells.
OBJECTIVE
Cilostazol is a selective inhibitor of phosphodiesterase 3 that increases intracellular cyclic AMP (cAMP) levels and activates protein kinase A, thereby inhibiting platelet aggregation and inducing peripheral vasodilation. We hypothesized that cilostazol may prevent inflammatory cytokine induced-nuclear factor (NF)-kappaB activation by activating AMP-activated protein kinase (AMPK) in vascular endothelial cells.


RESULTS
Cilostazol was observed to activate AMPK and its downstream target, acetyl-CoA carboxylase, in human umbilical vein endothelial cells (HUVEC). Phosphorylation of AMPK with cilostazol was not affected by co-treatment with an adenylate cyclase inhibitor, SQ 22536, and a cell-permeable cAMP analogue, pCTP-cAMP, did not induce AMPK phosphorylation and had no effect on cilostazol-induced AMPK phosphorylation, suggesting that cilostazol-induced AMPK activation occurs through a signalling pathway independent of cyclic AMP. Cilostazol also dose-dependently inhibited tumour necrosis factor alpha (TNFalpha)-induced NF-kappaB activation and TNFalpha-induced I kappa B kinase activity. Furthermore, cilostazol attenuated the TNFalpha-induced gene expression of various pro-inflammatory and cell adhesion molecules, such as vascular cell adhesion molecule-1, E-selectin, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 (MCP-1), and PECAM-1 in HUVEC. RNA interference of AMPK alpha 1 or the AMPK inhibitor compound C attenuated cilostazol-induced inhibition of NF-kappaB activation by TNFalpha.


CONCLUSIONS
In the light of these findings, we suggest that cilostazol might attenuate the cytokine-induced expression of adhesion molecule genes by inhibiting NF-kappaB following AMPK activation.
Hattori
Yoshiyuki
Y
Department of Endocrinology and Metabolism, Dokkyo University School of Medicine, Mibu, Tochigi 321-0293, Japan.
Suzuki
Kunihiro
K
Tomizawa
Atsuko
A
Hirama
Noriko
N
Okayasu
Toshie
T
Hattori
Sachiko
S
Satoh
Hiroko
H
Akimoto
Kazumi
K
Kasai
Kikuo
K
D000091162:AMP-Activated Protein Kinase Kinases; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D000077407:Cilostazol; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019040:E-Selectin / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013777:Tetrazoles / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D019040:E-Selectin; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D010726:Phosphodiesterase Inhibitors; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012333:RNA, Messenger; D013777:Tetrazoles; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D000072000:NF-KappaB Inhibitor alpha; D000242:Cyclic AMP; D011494:Protein Kinases; D000091162:AMP-Activated Protein Kinase Kinases; D000077407:Cilostazol