Role of DNA-dependent protein kinase in neuronal survival
Role of DNA-dependent protein kinase in neuronal survival
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DOI：
10.1046/j.1471-4159.2001.00380.x
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发表时间：
2001-07-01
影响因子：
4.7
通讯作者：
Naegele, JR
中科院分区：
文献类型：
--
作者：
Chechlacz, M;Vemuri, MC;Naegele, JR
DNA依赖蛋白激酶(DNA-PK)是一种DNA修复酶，由一个称为Ku70/80的DNA结合组分和一个称为DNA-PKcs的催化亚基组成。许多研究人员利用来自严重联合免疫缺陷(SCID)小鼠的DNA-PKcs缺陷细胞和细胞系来研究DNA修复和凋亡。然而，人们对这些小鼠的中枢神经系统知之甚少。本研究采用新生野生型和SCID小鼠大脑半球原代培养神经元，探讨DNA-PK功能缺失对神经元成熟和存活的影响。纯化的神经元培养在轴突形成和神经元标志物的表达方面发育类似，但SCID培养显示死亡细胞的百分比显著增加。此外，当星状孢子素诱导细胞凋亡时，SCID神经元死亡更快，数量更多。凋亡的SCID神经元出现核固缩、DNA断裂和caspase-3激活，但一般的caspase抑制剂N-苄氧羰基-Val-Ala-Asp-(O-甲基)氟甲基酮处理不能阻止星形孢子素诱导的细胞凋亡。我们的结论是，培养的SCID神经元中DNA-PK缺乏可能导致DNA损伤的积累，并增加对caspase非依赖形式的程序性细胞死亡的易感性。
DNA-dependent protein kinase (DNA-PK) is a DNA repair enzyme composed of a DNA-binding component called Ku70/80 and a catalytic subunit called DNA-PKcs. Many investigators have utilized DNA-PKcs-deficient cells and cell lines derived from severe combined immunodeficiency (scid) mice to study DNA repair and apoptosis. However, little is known about the CNS of these mice. This study was carried out using primary neuronal cultures derived from the cerebral hemispheres of new-born wild-type and scid mice to investigate the effects of loss of DNA-PK function on neuronal maturation and survival. Purified neuronal cultures developed comparably in terms of neurite formation and expression of neuronal markers, but scid cultures showed a significant increase in the percentage of dying cells. Furthermore, when apoptosis was induced by staurosporine, scid neurons died more rapidly and in higher numbers. Apoptotic scid neurons exhibited nuclear condensation, DNA fragmentation and caspase-3 activation, but treatment with the general caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-(O-methyl) fluoromethyl ketone did not prevent staurosporine-induced apoptosis. We conclude that a DNA-PK deficiency in cultured scid neurons may cause an accumulation of DNA damage and increased susceptibility to caspase-independent forms of programmed cell death.