Johnson Kyle, Liu Li, Majdzadeh Nazanin, Chavez Cindy, Chin Paul C, Morrison Brad, Wang Lulu, Park Jane, Chugh Priti, Chen Hsin-Mei, D'Mello Santosh R
Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas 75083, USA.
J Neurochem. 2005 May;93(3):538-48. doi: 10.1111/j.1471-4159.2004.03004.x.
Increasing evidence suggests that neuronal apoptosis is triggered by the inappropriate activation of cyclin-dependent kinases leading to an abortive re-entry of neurons into the cell cycle. Pharmacological inhibitors of cell-cycle progression may therefore have value in the treatment of neurodegenerative diseases in humans. GW8510 is a 3' substituted indolone that was developed recently as an inhibitor of cyclin-dependent kinase 2 (CDK2). We found that GW8510 inhibits the death of cerebellar granule neurons caused by switching them from high potassium (HK) medium to low potassium (LK) medium. Although GW8510 inhibits CDK2 and other CDKs when tested in in vitro biochemical assays, when used on cultured neurons it only inhibits CDK5, a cytoplasmic CDK that is not associated with cell-cycle progression. Treatment of cultured HEK293T cells with GW8510 does not inhibit cell-cycle progression, consistent with its inability to inhibit mitotic CDKs in intact cells. Neuroprotection by GW8510 is independent of Akt and MEK-ERK signaling. Furthermore, GW8510 does not block the LK-induced activation of Gsk3beta and, while inhibiting c-jun phosphorylation, does not inhibit the increase in c-jun expression observed in apoptotic neurons. We also examined the effectiveness of other 3' substituted indolone compounds to protect against neuronal apoptosis. We found that like GW8510, the VEGF Receptor 2 Kinase Inhibitors [3-(1H-pyrrol-2-ylmethylene)-1,3-dihydroindol-2-one], {(Z)-3-[2,4-Dimethyl-3-(ethoxycarbonyl)pyrrol-5-yl)methylidenyl]indol-2-one} and [(Z)-5-Bromo-3-(4,5,6,6-tetrahydro-1H-indol-2-ylmethylene)-1,3-dihydroindol-2-one], the Src family kinase inhibitor SU6656 and a commercially available inactive structural analog of an RNA-dependent protein kinase inhibitor 5-Chloro-3-(3,5-dichloro-4-hydroxybenzylidene)-1,3-dihydro-indol-2-one, are all neuroprotective when tested on LK-treated neurons. Along with our recent identification of the c-Raf inhibitor GW5074 (also a 3' substituted indolone) as a neuroprotective compound, our findings identify the 3' substituted indolone as a core structure for the designing of neuroprotective drugs that may be used to treat neurodegenerative diseases in humans.
越来越多的证据表明，细胞周期蛋白依赖性激酶的不适当激活会引发神经元凋亡，导致神经元异常重新进入细胞周期。因此，细胞周期进程的药理学抑制剂可能对治疗人类神经退行性疾病具有价值。GW8510是一种3' 取代的吲哚酮，它是最近开发的一种细胞周期蛋白依赖性激酶2（CDK2）抑制剂。我们发现，GW8510可抑制将小脑颗粒神经元从高钾（HK）培养基转换为低钾（LK）培养基所导致的细胞死亡。尽管在体外生化试验中测试时，GW8510可抑制CDK2和其他细胞周期蛋白依赖性激酶，但在培养的神经元上使用时，它仅抑制CDK5，一种与细胞周期进程无关的细胞质细胞周期蛋白依赖性激酶。用GW8510处理培养的HEK293T细胞不会抑制细胞周期进程，这与其无法在完整细胞中抑制有丝分裂细胞周期蛋白依赖性激酶一致。GW8510的神经保护作用独立于Akt和MEK-ERK信号传导。此外，GW8510不会阻断LK诱导的Gsk3β激活，并且在抑制c-jun磷酸化的同时，不会抑制在凋亡神经元中观察到的c-jun表达增加。我们还研究了其他3' 取代的吲哚酮化合物对预防神经元凋亡的有效性。我们发现，与GW8510一样，VEGF受体2激酶抑制剂[3-(1H-吡咯-2-基亚甲基)-1,3-二氢吲哚-2-酮]、{(Z)-3-[2,4-二甲基-3-(乙氧基羰基)吡咯-5-基)亚甲基]吲哚-2-酮}和[(Z)-5-溴-3-(4,5,6,6-四氢-1H-吲哚-2-基亚甲基)-1,3-二氢吲哚-2-酮]、Src家族激酶抑制剂SU6656以及一种市售的RNA依赖性蛋白激酶抑制剂5-氯-3-(3,5-二氯-4-羟基亚苄基)-1,3-二氢吲哚-2-酮的无活性结构类似物，在对LK处理过的神经元进行测试时均具有神经保护作用。连同我们最近鉴定出c-Raf抑制剂GW5074（也是一种3' 取代的吲哚酮）为神经保护化合物一起，我们的研究结果确定3' 取代的吲哚酮是设计可用于治疗人类神经退行性疾病的神经保护药物的核心结构。
