Presence of DNA Fragmentation and Lack of Neuroprotective Effect in DFF45 Knockout Mice Subjected to Traumatic Brain Injury
Presence of DNA Fragmentation and Lack of Neuroprotective Effect in DFF45 Knockout Mice Subjected to Traumatic Brain Injury
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遭受创伤性脑损伤的 DFF45 基因敲除小鼠中存在 DNA 碎片且缺乏神经保护作用
作者：
A. Yakovlev;X. Di;V. Movsesyan;Paul G. M. Mullins;Geping Wang;Hamid A. Boulares;Jianhua Zhang;Ming Xu;A. Faden
背景细胞凋亡在创伤性脑损伤（TBI）后神经细胞丢失和相关神经功能缺损中起重要的病理生理作用。DNA片段化是神经元凋亡的特征性生化特征之一，在实验性TBI后观察到。DFF 45和DFF 40是必不可少的DNA片段在各种模型的apoptosis.Materials和MethodsWe使用小鼠DFF 45和野生型对照缺陷。使用体内和体外测定分析由TBI诱导的寡核小体DNA片段化。通过Western分析评估DFF 45和DFF 40蛋白的表达和完整性。其他结果的测量包括神经评分，学习/记忆测试，病变体积测量（MRI），并在体外细胞活力的评估amongother.ResultsWe比较了DFF 45基因敲除小鼠和野生型对照的控制皮质撞击（CCI）创伤的影响。对野生型和DFF 45敲除小鼠脑皮质中TBI诱导的DNA片段化的分析表明，DFF 45敲除小鼠在TBI后发生DNA的寡核小体切割，尽管有些延迟。DFF 45敲除与野生型对照相比，TBI后的行为结果或病变体积没有显着差异。使用体外重建系统，我们还表明，裂解DFF 45的caspase-3是不足以诱导大鼠大脑皮层的蛋白质提取物的DNA片段。我们发现，在大鼠脑皮层TBI后诱导的核酸内切酶活性依赖于Mg ~（2+）和Ca ~（2+）的存在，但不受Zn ~（2+）的抑制。DFF 45敲除的原代神经元培养物未能显示响应于星形孢菌素的DNA梯状化，但在用依托泊苷处理后确实显示出显著的DNA片段化，尽管延迟。与此相反，野生型动物的原代神经元表现出显着的DNA片段化处理后与staurosporine或etoposided.ConclusionsThe结果表明，除了DFF 45/40，其他内切酶可能是必不可少的染色质降解过程中的神经元凋亡在成人脑外伤后。
BackgroundApoptosis plays an important pathophysiologic role in neuronal cell loss and associated neurologic deficits following traumatic brain injury (TBI). DNA fragmentation represents one of the characteristic biochemical features of neuronal apoptosis and is observed after experimental TBI. DFF45 and DFF40 are essential for DNA fragmentation in various models of apoptosis.Materials and MethodsWe used mice deficient in DFF45 and wild-type controls. Oligonucleosomal DNA fragmentation induced by TBI was analyzed using in vivo and in vitro assays. Expression and integrity of DFF45 and DFF40 proteins was assessed by Western analysis. Other outcome measurements included neurologic scoring, learning/memory tests, lesion volume measurements (MRI), and assessment of cell viability in vitro among others.ResultsWe compared the effects of controlled cortical impact (CCI) trauma in DFF45 knockout mice and wild-type controls. Analysis of TBI-induced DNA fragmentation in brain cortex from wild-type and DFF45 knockout mice indicates that, although somewhat delayed, oligonucleosomal cleavage of DNA occurs after TBI in DFF45 knockout mice. DFF45 knockouts showed no significant differences in behavioral outcomes or lesion volumes after TBI as compared to wild-type controls. Using an in vitro reconstitution system, we also demonstrated that cleavage of DFF45 by caspase-3 is not sufficient for DNA fragmentation induced by protein extracts from rat brain cortex. We found that endonuclease activity induced in rat brain cortex following TBI depends on the presence of Mg2+ and Ca2+, but is not inhibited by Zn2+. Primary neuronal cultures from DFF45 knockouts failed to show DNA laddering in response to staurosporine, but did show prominent, albeit delayed, DNA fragmentation following treatment with etoposide. In contrast, primary neurons from wildtype animals demonstrated marked DNA fragmentation following treatment with staurosporine or etoposide.ConclusionsThe results of this study suggest that, in addition to DFF45/40, other endonucleases may be essential for chromatin degradation during neuronal apoptosis in adult brain after TBI.
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影响因子：
3.9
作者：
BARRY, MA;EASTMAN, A
通讯作者：
EASTMAN, A
影响因子：
3.7
作者：
Cigola, E;Kajstura, J;Anversa, P
通讯作者：
Anversa, P
DOI：
--
发表时间：
1995
期刊：
The American journal of pathology
影响因子：
--
作者：
A. Rink;K. Fung;J. Trojanowski;V. Lee;E. Neugebauer;Tracy K. McIntosh
通讯作者：
A. Rink;K. Fung;J. Trojanowski;V. Lee;E. Neugebauer;Tracy K. McIntosh
DOI：
10.1073/pnas.95.15.8461
发表时间：
1998-07-21
影响因子：
11.1
作者：
Liu, XS;Li, P;Wang, XD
通讯作者：
Wang, XD
DOI：
10.1073/pnas.95.21.12480
发表时间：
1998-10
影响因子：
11.1
作者：
Jianhua Zhang;Xuesong Liu;David C. Scherer;L. Kaer;Xiaodong Wang;Ming Xu
通讯作者：
Jianhua Zhang;Xuesong Liu;David C. Scherer;L. Kaer;Xiaodong Wang;Ming Xu