Role of Cardiolipin Oxidation After Traumatic Brain Injury in Immature Rat

是细胞凋亡性死亡的关键早期事件。Cyt c绑定到 线粒体内膜与心磷脂(CL)的结合 仅存在于真核细胞的线粒体膜内。最近我们展示了新的氧化还原 Cytc的催化性能是通过它与CL和PS的相互作用而实现的。 产生的产物CL和PS氢过氧化氢在两条凋亡途径中扮演重要信号- 细胞凋亡因子从线粒体释放到胞浆的调控及PS标记的外化 用于吞噬的凋亡细胞。我们的假设是，TBI启动了ROS和氧化的过度产生 由CL/Cyt c复合体催化的CL，这是从 线粒体。氯的氧化是由紧密结合在线粒体膜上的细胞色素c催化的。 通过其在神经元中与CL的络合物。因此，我们预测，TBI诱导CL氧化和细胞凋亡 可以通过抗氧化策略和处理来预防，通过以下方式降低CL对氧化的敏感度 对其脂肪酸残留物的饮食控制。在本提案中，我们将使用受控皮质冲击(CCI)模型 在出生后一天(PND)17只大鼠结合体外研究来验证这些特定的假说和 解决以下具体目标：1)确定ROS产生的程度、空间和时间模式； 脑外伤后幼脑和谷氨酸暴露后神经元中抗氧化剂的耗竭和CL的氧化。2) 确定抗氧化剂和饮食操作抑制线粒体CL氧化和 保护脑损伤后未成熟脑和谷氨酸暴露后神经元的细胞凋亡。这些研究 将利用新开发的氧化脂质组学技术提供重要的机制 细胞色素c-CL相互作用在儿童颅脑损伤后神经细胞凋亡中的作用 模特。与这项建议的具体目标相关的体内研究将总的CL氧化与Cytc联系起来 释放和细胞凋亡一直缺乏。选择性地调节Cytc释放的能力可能导致 针对脑外伤的靶向治疗，最终改善儿童的预后。 项目说明第6页

is a critical early event in apoptotic cell death. Cyt c is bound to the inner mitochondrial membrane by its association with cardiolipin (CL), an anionic phospholipid found exclusively in the inner mitochondrial membrane of eukarydtic cells. Recently we have shown novel redox catalytic properties of cyt c realized though its interactions with CL and PS resulting in their selective oxidation. The resulting products, CL and PS hydroperoxides act as important signals in two apoptotic pathways - regulation of release of apoptotic factors from mitochondria into cytosol, and externalization of PS marking apoptotic cells for phagocytosis. Our hypothesis is that TBI initiates excessive production of ROS and oxidation of CL catalyzed by CL/cyt c complex, which is required for the release of pro-apoptotic factors from mitochondria. CL oxidation is catalyzed by a pool of cyt c that is tightly bound to inner mitochondrial membrane by its complex with CL in neurons. As a consequence, we predict that TBI induced CL oxidation and apoptosis can be prevented by antioxidant strategies and treatments decreasing susceptibility of CL to oxidation by dietary manipulation of its fatty acid residues. In this proposal we will use controlled cortical impact (CCI) model of TBI in post-natal day (PND) 17 rats coupled with in vitro studies to test these specific hypotheses and address the following specific aims: 1) Determine the degree, spatial and temporal pattern of ROS production, antioxidant depletion and CL oxidation in immature brain after TBI and in neurons after glutamate exposure. 2) Determine the potential of antioxidants and dietary manipulation to inhibit mitochondrial CL oxidation and protect against apoptosis in immature brain after TBI and in neurons after glutamate exposure. These studies will employ the newly developing technology of oxidative lipidomics to provide important mechanistic information on the role of cyt c -CL interactions in neuronal apoptosis after pediatric TBI in an experimental model. Relevant to the specific aims of this proposal in vivo studies linking overall CL oxidation with cyt c release and apoptosis have been lacking. The ability to selectively modulate Cyt c release could lead to targeted therapies for TBI and ultimately improve outcome for children. Project Description Page 6