Maroney A C, Glicksman M A, Basma A N, Walton K M, Knight E, Murphy C A, Bartlett B A, Finn J P, Angeles T, Matsuda Y, Neff N T, Dionne C A
Cephalon Incorporated, West Chester, Pennsylvania 19380, USA.
J Neurosci. 1998 Jan 1;18(1):104-11. doi: 10.1523/JNEUROSCI.18-01-00104.1998.
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.
正在经历凋亡的神经元可被营养因子拯救，这些营养因子能同时增强细胞外信号调节激酶（ERK）的活性，并降低c-Jun氨基末端激酶（JNK）和p38的活性。我们鉴定出一种分子CEP-1347（KT7515），它能拯救正在经历凋亡的运动神经元，并研究了其对ERK1和JNK1活性的影响。在无营养因子的情况下，培养的大鼠胚胎运动神经元在接种后24-48小时开始死亡。在最初的24小时内，ERK1活性未发生变化，而JNK1活性增加了四倍。CEP-1347能完全拯救运动神经元至少72小时，其半数有效浓度（EC50）为20±2 nM。CEP-1347不会改变ERK1活性，但能迅速抑制JNK1的激活。CEP-1347对JNK1激活的半数抑制浓度（IC50）与运动神经元存活的EC50相同。CEP-1347对JNK1激活的抑制作用并非运动神经元所特有。在紫外线照射、渗透休克和糖基化抑制等条件下，CEP-1347也能抑制Cos7细胞中的JNK1活性。CEP-1347对JNK1信号通路的抑制作用似乎具有选择性，因为在经历渗透休克的Cos7细胞中，CEP-1347不会抑制p38调节的丝裂原活化蛋白激酶激活的蛋白激酶-2（MAPKAP2）的活性。CEP-1347的直接分子靶点不是JNK1，因为在共转染了MEKK1和JNK1 cDNA构建体的Cos7细胞中，CEP-1347不会抑制JNK1活性。这是首次证明一种小分子有机化合物能促进运动神经元存活并同时抑制JNK1信号级联反应。
