Motoneuron apoptosis is blocked by CEP-1347 (KT 7515), a novel inhibitor of the JNK signaling pathway.
Neurons undergoing apoptosis can be rescued by trophic factors that simultaneously increase the activity of extracellular signal-regulated kinase (ERK) and decrease c-Jun N-terminal kinase (JNK) and p38. We identified a molecule, CEP-1347 (KT7515), that rescues motoneurons undergoing apoptosis and investigated its effect on ERK1 and JNK1 activity. Cultured rat embryonic motoneurons, in the absence of trophic factor, began to die 24-48 hr after plating. During the first 24 hr ERK1 activity was unchanged, whereas JNK1 activity increased fourfold. CEP-1347 completely rescued motoneurons for at least 72 hr with an EC50 of 20 +/- 2 nM. CEP-1347 did not alter ERK1 activity but rapidly inhibited JNK1 activation. The IC50 of CEP-1347 for JNK1 activation was the same as the EC50 for motoneuron survival. Inhibition of JNK1 activation by CEP-1347 was not selective to motoneurons. CEP-1347 also inhibited JNK1 activity in Cos7 cells under conditions of ultraviolet irradiation, osmotic shock, and inhibition of glycosylation. Inhibition by CEP-1347 of the JNK1 signaling pathway appeared to be selective, because CEP-1347 did not inhibit p38-regulated mitogen-activated protein kinase-activated protein kinase-2 (MAPKAP2) activity in Cos7 cells subjected to osmotic shock. The direct molecular target of CEP-1347 was not JNK1, because CEP-1347 did not inhibit JNK1 activity in Cos7 cells cotransfected with MEKK1 and JNK1 cDNA constructs. This is the first demonstration of a small organic molecule that promotes motoneuron survival and that simultaneously inhibits the JNK1 signaling cascade.
Maroney
A C
AC
Cephalon Incorporated, West Chester, Pennsylvania 19380, USA.
Glicksman
M A
MA
Basma
A N
AN
Walton
K M
KM
Knight
E
E
Murphy
C A
CA
Bartlett
B A
BA
Finn
J P
JP
Angeles
T
T
Matsuda
Y
Y
Neff
N T
NT
Dionne
C A
CA
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D002227:Carbazoles / Q000138:chemical synthesis / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology*; D005333:Fetus / Q000166:cytology; D015870:Gene Expression; D007093:Imidazoles / Q000494:pharmacology; D026121:Indole Alkaloids; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009046:Motor Neurons / Q000166:cytology* / Q000201:enzymology / Q000648:ultrastructure; D016501:Neurites / Q000502:physiology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000235:genetics; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases
D002227:Carbazoles; D004791:Enzyme Inhibitors; D007093:Imidazoles; D026121:Indole Alkaloids; D047428:Protein Kinase Inhibitors; D011725:Pyridines; C049985:staurosporine aglycone; D002795:Choline O-Acetyltransferase; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; C093642:SB 203580