Anti-apoptotic action of (2S,3S,4R)-N"-cyano-N-(6-amino-3,4-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N'-benzylguanidine (KR-31378) by suppression of the phosphatase and tensin homolog deleted from chromosome 10 phosphorylation and increased phosphorylation of casein kinase2/Akt/ cyclic AMP response element binding protein via maxi-K channel opening in neuronal cells.
This study shows the signaling pathway by which (2S,3S,4R)-N"-cyano-N-(6-amino-3,4-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N'-benzylguanidine (KR-31378) prevents tumor necrosis factor (TNF)-alpha-induced neuronal cell death. KR-31378 restored TNF-alpha-induced decreased cell viability of SK-N-SH. U87-MG cells (PTEN-null glioblastoma cell line) transfected with expression vectors for sense PTEN (phosphatase and tensin homolog deleted from chromosome 10) showed significantly decreased cell viability, which was restored by KR-31378. TNF-alpha-induced increased PTEN phosphorylation and decreased phosphorylation of Akt/cyclic AMP response element-binding protein (CREB) in SK-N-SH cells were concentration-dependently reversed by KR-31378, those of which were antagonized by iberiotoxin, a maxi-K channel blocker. TNF-alpha and apigenin, a casein kinase2 (CK2) inhibitor, showed decreased CK2 phosphorylation and increased PTEN phosphorylation, which were reversed by KR-31378. KR-31378 increased K(+) currents by activating the maxi-K channels in SK-N-SH cells, with suppression of TNF-alpha-induced increase in cytosolic Ca(2+) and elevation of suppressed mitochondrial membrane potential, all of which were antagonized by iberiotoxin. It is suggested that increase in cell viability by KR-31378 is ascribed to the maxi-K channel opening-coupled upregulation of CK2/Akt/CREB phosphorylation and downregulation of PTEN phosphorylation in association with increased Bcl-2 and decreased Bax levels.
Kim
Ki Young
KY
Medicinal Science Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600, Korea.
Lee
Jeong Hyun
JH
Park
Jae Hong
JH
Yoo
Mi-Ae
MA
Kwak
Yong-Geun
YG
Kim
Sun-Ok
SO
Yoo
Sung-Eun
SE
Hong
Ki Whan
KW
D017209:Apoptosis / Q000187:drug effects*; D047390:Casein Kinase II / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D015640:Ion Channel Gating; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008564:Membrane Potentials; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D051059:PTEN Phosphohydrolase; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D011714:Pyrans / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D006146:Guanidines; D051036:Large-Conductance Calcium-Activated Potassium Channels; C438686:N''-cyano-N-(6-amino-3,4-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N'-benzylguanidine; D010455:Peptides; D026902:Potassium Channel Blockers; D024681:Potassium Channels, Calcium-Activated; D011518:Proto-Oncogene Proteins; D011714:Pyrans; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C064719:iberiotoxin; D000242:Cyclic AMP; C494918:AKT1 protein, human; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human