PKCdelta mediates Nrf2-dependent protection of neuronal cells from NO-induced apoptosis.
A chemical inhibitor library of 84 compounds was screened to investigate the signaling pathway(s) leading to activation of Nrf2 in response to nitric oxide (NO). We identified the protein kinase C delta (PKCdelta) inhibitor rottlerin as the only compound that reduced NO-induced ARE-luciferase reporter activity and diminished NO-induced up-regulation of two Nrf2/ARE-regulated proteins - NAD(P)H:quinone oxidoreductase-1 (NQO1) and hemeoxygenase-1 (HO-1) in SH-Sy5y cells. Rottlerin also sensitized neuroblastoma cells and mouse primary cortical neurons to NO-induced apoptosis. Stable over-expression of PKCdelta augmented NO-induced, ARE-dependent gene expression of HO-1 in SH-Sy5y cells, which were more protected from NO killing. Conversely, NO-induced ARE-dependent gene expression was reduced in PKCdelta-knockdown SH-EP cells, which displayed greater sensitivity to apoptosis. PKCdelta(-/-) cortical neurons exhibited increased NO-induced apoptosis and less HO-1 mRNA and protein induction compared with wild type neurons. Hence, PKCdelta is an important positive modulator of NO-induced Nrf2/ARE-dependent signaling that counteracts NO-mediated apoptosis in neuronal cells.
Zhang
Jindan
J
Cell Death and Human Disease Group, Division of Cancer and Developmental Cell Biology, Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673, Republic of Singapore.
Hung
Amos C
AC
Ng
Poh Yong
PY
Nakayama
Keiichi
K
Hu
Yuanyu
Y
Li
Baojie
B
Porter
Alan G
AG
Dhakshinamoorthy
Saravanakumar
S
D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D020650:Combinatorial Chemistry Techniques; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017930:Genes, Reporter / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000235:genetics; D008156:Luciferases / Q000235:genetics; D051379:Mice; D016660:NAD(P)H Dehydrogenase (Quinone); D009252:NADPH Dehydrogenase / Q000235:genetics; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D009569:Nitric Oxide / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D047428:Protein Kinase Inhibitors; D009569:Nitric Oxide; D008156:Luciferases; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C491732:Nqo1 protein, mouse; D009252:NADPH Dehydrogenase; D051745:Protein Kinase C-delta