Role of prohibitin in ischemic brain injury

摘要 线粒体蛋白质Prohibitin（PHB）是生命所必需的。它对细胞活动的重要性 通过以下事实证明：在小鼠中，缺失PHB是胚胎致死的，并且迄今为止没有突变 在任何疾病条件下，在PHB的编码区都发现了，这表明 体细胞突变是有害的。已经证明，PHB对于以下方面至关重要： 线粒体在应激情况下的功能，因为它在缺血预处理（IPC）中上调。 在前一个资助期，我们使用神经元特异性的PHB转基因小鼠，证明了 选择性神经元PHB表达导致对大脑中动脉的显著神经保护作用， 动脉闭塞（MCAO）引起的脑损伤。然而，这种重要蛋白质的功能如何 在IPC中的调节，以及它在其他神经系统疾病中的失调，仍然存在 令人惊讶的未知。在探索PHB调节机制的过程中，我们发现， 氧化物（NO）是IPC和PHB上调所必需的。因此，我们调查了 NO和PHB之间的相互作用，发现NO修饰后的PHB，通过 蛋白质S-亚硝基化。在此更新申请中，我们建议研究PHBS- 亚硝酰化和机制的潜在功能调节的聚羟基丁酸的NO。我们的中央 假设是PHB亚硝基化对其神经保护功能至关重要，并且干扰 的亚硝化是有害的。我们将使用一个突变敲入小鼠，其中唯一的 突变了PHB蛋白的半胱氨酸残基，使其不能被亚硝基化， 神经元敲除小鼠，其中通过表达野生型的AAV来补充PHB缺失 或非亚硝基化的C69 S突变体，以分析NO调节的机制以及 在IPC中，对PHB功能的PHB亚硝基化损失。三个具体目标将系统地检验 假说.拟议研究的结果将揭示一个以前未描述的监管 这可能是一种新的机制，可以使有中风和其他神经系统疾病风险的患者受益。

ABSTRACT The mitochondrial protein Prohibitin (PHB) is essential for life. Its importance to cellular activities is attested by the fact that deletion of PHB is embryonic lethal in mice and that to date no mutation has been found in the coding region of PHB in any disease conditions, indicating that PHB integrity is essential and that somatic mutation is detrimental. PHB has been shown to be critical for mitochondrial function in stress situations, as it is upregulated in ischemic preconditioning (IPC). In the previous funding period, using neuron specific PHB transgenic mice, we demonstrated that selective neuronal PHB expression leads to remarkable neuroprotection against middle cerebral arterial occlusion (MCAO) induced brain injury. However, how this important protein is functionally regulated in IPC, as well as how it is dysregulated in other neurological conditions, remain surprisingly unknown. In exploring the mechanisms of PHB regulation, we discovered that nitric oxide (NO) is required for both IPC and PHB upregulation. Therefore, we investigated the interaction between NO and PHB and found that NO modifies PHB post-translationally, through protein s-nitrosylation. In this renewal application, we propose to study the effects of PHB S- nitrosylation and the mechanisms underlying functional regulation of PHB by NO. Our central hypothesis is that PHB nitrosylation is critical for its neuroprotective function and that disturbances of PHB nitrosylation is detrimental. We will use a mutant knockin mouse, in which the sole cysteine residue of PHB protein is mutated so that PHB cannot be nitrosylated, and a PHB neuronal knockout mouse, in which PHB deletion is complemented by AAV expressing wild type or non-nitrosylated C69S mutant to analyze the mechanisms of NO regulation and the effects of loss of PHB nitrosylation on PHB function, in IPC. Three specific aims will systematically test the hypothesis. The results of the proposed studies will reveal a previously undescribed regulatory mechanism of PHB and could benefit patients at risk of stroke and other neurological conditions.