Temporal relationship of peroxymtrite-induced oxidative damage, calpain-mediated cytoskeletal degradation and neurodegeneration after traumatic brain injury
Temporal relationship of peroxymtrite-induced oxidative damage, calpain-mediated cytoskeletal degradation and neurodegeneration after traumatic brain injury
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DOI：
10.1016/j.expneurol.2007.01.023
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发表时间：
2007-05-01
影响因子：
5.3
通讯作者：
Hall, Edward D.
中科院分区：
文献类型：
--
作者：
Deng, Ying;Thompson, Brian M.;Hall, Edward D.
在严重的单侧控制皮质撞击(CCI)创伤性脑损伤(TBI)模型中，我们评估了PN诱导的氧化损伤的时间和空间特征及其与Calain介导的细胞骨架退化和神经退行性变的关系。对幼年雄性CF-I小鼠同侧大脑皮质损伤后30min、1、3、6、12、24、48、72h和7d的氧化损伤标志物3-硝基酪氨酸(3NT)和4-羟基壬烯醛(4HNE)进行了定量的时程研究。其次，通过对细胞骨架蛋白α-血影蛋白降解产物的定量Western-blotting测定，分析了钙激活、钙蛋白酶介导的蛋白降解的时间进程。最后用De Olmos银染法观察神经退行性变的时间进程。两种氧化损伤标志物均在损伤后即刻(30min)升高，并在伤后3~6h升高，然后恢复到基线水平。在免疫染色研究中，PN选择性标记3NT和脂质过氧化标记4HNE在损伤的皮质组织中强烈重叠。作为钙蛋白酶介导的细胞骨架降解生物标志物的α-血影蛋白降解产物在损伤后也有所增加，但时间滞后于氧化损伤的峰值，直到损伤后24小时才达到最大值。反过来，细胞骨架的降解先于神经变性的高峰，发生在损伤后48小时。这些研究使我们假设，PN介导的氧化损伤是一个早期事件，有助于破坏钙离子稳态机制，导致大量的钙超载和钙蛋白酶激活，这是导致创伤后神经退化的最终共同途径。(C)2007 Elsevier Inc.保留所有权利。
We assessed the temporal and spatial characteristics of PN-induced oxidative damage and its relationship to calpain-mediated cytoskeletal degradation and neurodegeneration in a severe unilateral controlled cortical impact (CCI) traumatic brain injury (TBI) model. Quantitative temporal time course studies were performed to measure two oxidative damage markers: 3-nitrotyrosine (3NT) and 4-hydroxynonenal (4HNE) at 30 min, 1, 3, 6, 12, 24, 48, 72 h and 7 days after injury in ipsilateral cortex of young adult male CF- I mice. Secondly, the time course of Ca++-activated, calpain-mediated proteolysis was also analyzed using quantitative western-blot measurement of breakdown products of the cytoskeletal protein alpha-spectrin. Finally, the time course of neurodegeneration was examined using de Olmos silver staining. Both oxidative damage markers increased in cortical tissue immediately after injury (30 min) and elevated for the first 3-6 h before returning to baseline. In the immunostaining study, the PN-selective marker, 3NT, and the lipid peroxidation marker, 4HNE, were intense and overlapping in the injured cortical tissue. alpha-Spectrin breakdown products, which were used as biomarker for calpain-mediated cytoskeletal degradation, were also increased after injury, but the time course lagged behind the peak of oxidative damage and did not reach its maximum until 24 h post-injury. In turn, cytoskeletal degradation preceded the peak of neurodegeneration which occurred at 48 h post-injury. These studies have led us to the hypothesis that PN-mediated oxidative damage is an early event that contributes to a compromise of Ca++ homeostatic mechanisms which causes a massive Ca++ overload and calpain activation which is a final common pathway that results in post-traumatic neurodegeneration. (C) 2007 Elsevier Inc. All rights reserved.