Overexpression of protein kinase C isoforms protects RAW 264.7 macrophages from nitric oxide-induced apoptosis: involvement of c-Jun N-terminal kinase/stress-activated protein kinase, p38 kinase, and CPP-32 protease pathways.
Nitric oxide (NO) induces apoptotic cell death in murine RAW 264.7 macrophages. To elucidate the inhibitory effects of protein kinase C (PKC) on NO-induced apoptosis, we generated clones of RAW 264.7 cells that overexpress one of the PKC isoforms and explored the possible interactions between PKC and three structurally related mitogen-activated protein (MAP) kinases in NO actions. Treatment of RAW 264.7 cells with sodium nitroprusside (SNP), a NO-generating agent, activated both c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38 kinase, but did not activate extracellular signal-regulated kinase (ERK)-1 and ERK-2. In addition, SNP-induced apoptosis was slightly blocked by the selective p38 kinase inhibitor (SB203580) but not by the MAP/ERK1 kinase inhibitor (PD098059). PKC transfectants (PKC-beta II, -delta, and -eta) showed substantial protection from cell death induced by the exposure to NO donors such as SNP and S-nitrosoglutathione (GSNO). In contrast, in RAW 264.7 parent or in empty vector-transformed cells, these NO donors induced internucleosomal DNA cleavage. Moreover, overexpression of PKC isoforms significantly suppressed SNP-induced JNK/SAPK and p38 kinase activation, but did not affect ERK-1 and -2. We also explored the involvement of CPP32-like protease in the NO-induced apoptosis. Inhibition of CPP32-like protease prevented apoptosis in RAW 264.7 parent cells. In addition, SNP dramatically activated CPP32 in the parent or in empty vector-transformed cells, while slightly activated CPP32 in PKC transfectants. Therefore, we conclude that PKC protects NO-induced apoptotic cell death, presumably nullifying the NO-mediated activation of JNK/SAPK, p38 kinase, and CPP32-like protease in RAW 264.7 macrophages.
Jun
C D
CD
Department of Microbiology and Immunology, Wonkwang University School of Medicine, Iksan, Chonbuk, Korea. cdjun@wonnms.wonkwang.ac.kr
Oh
C D
CD
Kwak
H J
HJ
Pae
H O
HO
Yoo
J C
JC
Choi
B M
BM
Chun
J S
JS
Park
R K
RK
Chung
H T
HT
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism / Q000502:physiology*; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D004789:Enzyme Activation / Q000276:immunology; D007527:Isoenzymes / Q000096:biosynthesis / Q000502:physiology; D048031:JNK Mitogen-Activated Protein Kinases; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D009569:Nitric Oxide / Q000494:pharmacology*; D011493:Protein Kinase C / Q000096:biosynthesis* / Q000502:physiology; D015398:Signal Transduction / Q000276:immunology*; D048051:p38 Mitogen-Activated Protein Kinases
D061945:Caspase Inhibitors; D007527:Isoenzymes; D009569:Nitric Oxide; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases