Hall Edward D, Detloff Megan R, Johnson Kjell, Kupina Nancy C
Spinal Cord and Brain Injury Research Center, University of Kentucky Chandler Medical Center, Lexington, Kentucky 40536-0305, USA.
J Neurotrauma. 2004 Jan;21(1):9-20. doi: 10.1089/089771504772695904.
The role of reactive oxygen-induced oxidative damage to lipids (i.e., lipid peroxidation, LP) and proteins has been strongly supported in previous work. Most notably, a number of free radical scavengers and lipid antioxidants have been demonstrated to be neuroprotective in traumatic brain injury (TBI) models. However, the specific sources of reactive oxygen species (ROS), the time course of oxidative damage and its relationship to post-traumatic neurodegeneration in the injured brain have been incompletely defined. The present study was directed at an investigation of the role of the ROS, peroxynitrite (PON), in the acute pathophysiology of TBI and its temporal relationship to neurodegeneration in the context of the mouse model of diffuse head injury model. Male CF-1 mice were subjected to a moderately severe head injury and assessed at 1-, 3-, 6-, 12-, 24-, 48-, 72, 96- and 120-h post-injury for neurodegeneration using quantitative image analysis of silver staining and semi-quantitative analysis of PON-mediated oxidative damage to proteins (3-nitrotyrosine, 3-NT) and lipids (4-hydroxynonenal, 4-HNE). Significant evidence of silver staining was not apparent until 24-h post-injury, with peak staining seen between 72- and 120-h. This time-course of neurodegeneration was preceded by intense immunostaining for 3-NT and 4-HNE, which occurred within the first hour post-injury. The time course and staining pattern for 3-NT and 4-HNE were similar, with the highest staining intensity noted within the first 48-h in areas surrounding trauma-induced contusions. In the case of 3-NT, neuronal perikarya and processes and microvessels displayed staining. The temporal and spatial coincidence of protein nitration and LP damage suggests that PON is involved in both. However, lipid-peroxidative (4-HNE) immunoreactivity was broader and more diffuse than 3-NT, suggesting that other reactive oxygen mechanisms, such as iron-dependent LP, may also contribute to the more widespread 4-HNE immunoreactivity. This indicates that optimal pharmacological inhibition of post-traumatic oxidative damage in TBI may need to combine two functionalities: one to scavenge PON or PON-derived radicals, and the second to inhibit LP caused by multiple ROS species.
活性氧诱导的脂质氧化损伤（即脂质过氧化，LP）和蛋白质氧化损伤的作用在先前的研究中得到了有力支持。最值得注意的是，许多自由基清除剂和脂质抗氧化剂已被证明在创伤性脑损伤（TBI）模型中具有神经保护作用。然而，活性氧（ROS）的具体来源、氧化损伤的时间进程及其与受伤大脑中创伤后神经退行性变的关系尚未完全明确。本研究旨在探讨ROS过氧亚硝酸盐（PON）在TBI急性病理生理学中的作用及其在弥漫性头部损伤小鼠模型背景下与神经退行性变的时间关系。雄性CF-1小鼠遭受中度严重头部损伤，并在损伤后1、3、6、12、24、48、72、96和120小时进行评估，使用银染色的定量图像分析以及PON介导的蛋白质（3-硝基酪氨酸，3-NT）和脂质（4-羟基壬烯醛，4-HNE）氧化损伤的半定量分析来检测神经退行性变。银染色的明显证据直到损伤后24小时才出现，在72至120小时之间出现染色峰值。这种神经退行性变的时间进程之前是3-NT和4-HNE的强烈免疫染色，这发生在损伤后的第一小时内。3-NT和4-HNE的时间进程和染色模式相似，在创伤性挫伤周围区域，在最初的48小时内染色强度最高。就3-NT而言，神经元胞体、突起和微血管都显示出染色。蛋白质硝化和LP损伤在时间和空间上的一致性表明PON参与了两者。然而，脂质过氧化（4-HNE）免疫反应性比3-NT更广泛、更弥散，这表明其他活性氧机制，如铁依赖性LP，也可能导致更广泛的4-HNE免疫反应性。这表明，对TBI创伤后氧化损伤的最佳药理学抑制可能需要结合两种功能：一种是清除PON或PON衍生的自由基，另一种是抑制由多种ROS物种引起的LP。
