mitoNEET as a therapeutic target for TBI

积累的临床证据以及当代军事行动的经验表明， 创伤性脑损伤（TBI）是这场战争的标志性损伤，使我们的部队成为TBI的高危人群。 在2009年使用VA服务的327，388名OEF/OIF退伍军人中，6.7%被诊断患有TBI，其中73% 被诊断为创伤后应激障碍（PTSD）。然而，迄今为止， TBI的治疗，部分原因是对TBI的病理生物学的不完全理解。因此 迫切需要在这一研究领域取得进展。最近，我们发现吡格列酮 脑外伤后的神经保护作用，其作用机制可能直接与其与神经元的相互作用有关。 线粒体蛋白mitoNEET。与这些想法一致，我们的初步结果表明吡格列酮不是 在mitoNEET敲除动物中具有保护性，并且用特异性mitoNEET配体（NL 1）治疗， TBI后的神经保护拟定实验旨在通过以下方式阐明机制： 吡格列酮通过检验新的假设， 吡格列酮通过mitoNEET相互作用直接改善线粒体功能障碍。为了验证这一 假设我们提出了三个具体目标，包括使用多种创新工具和技术， 我们手头上，特别是使用mitoNEET无效转基因小鼠，一种新的mitoNEET配体（NL-1）， 拮抗剂NL-3。在具体目标1中，我们将确定以下药物的最佳剂量和治疗窗： 吡格列酮维持损伤后线粒体稳态的机会。这些测量将，对于 第一次，测量损伤核心中突触和非突触线粒体的线粒体功能障碍， 一个动物的半影在特定目标2中，将测量皮质保留和行为的程度 使用确定的最佳剂量，TBI后通过吡格列酮治疗介导的改善 具体目标1。在这个目标中，我们将使用T2加权和DTI MRI纵向评估皮质的变化， 在损伤后-3，3，7，14，28和168天， 受伤后168天此外，我们还将测量急性运动，系列认知功能测试和攻击性 行为功能和恐惧条件反射（PTSD的慢性测量），以评估功能性 治疗的结果。具体目标3将确定吡格列酮提供 通过验证吡格列酮的治疗作用是通过相互作用介导的假设， 关于MitoNeet该目的将采用转基因mitoNEET敲除小鼠与新的mitoNEET敲除小鼠串联使用。 特异性配体（NL-1）和mitoNEET拮抗剂（NL-3）。将在24小时测量线粒体生物能量学 并在TBI后测量行为结果和组织保留。这些研究的结果将不会 他们不仅阐明了TBI神经病理学中涉及的基本过程， 将FDA化合物重新用于治疗TBI和拟议的实验可能会查明潜在的 治疗TBI和其他神经元损伤的新靶点。

Accumulating clinical evidence, as well as experience in contemporary military operations, suggests that traumatic brain injury (TBI) is the signature injury of this war making our troops a high-risk population for TBI. Among the 327,388 OEF/OIF veterans using VA services in 2009, 6.7% were diagnosed with TBI of which 73% of those were diagnosed with posttraumatic stress disorder (PTSD). However, to date there is no approved treatment for TBI, in part due to an incomplete understanding of the pathobiology underlying TBI. Therefore progress in this area of research is desperately needed. Recently, we have shown that pioglitazone is neuroprotective following TBI and that its mechanism of action may be directly related to its interactions with the mitochondrial protein mitoNEET. Consistent with these ideas, our preliminary results indicate pioglitazone is not protective in mitoNEET knockout animals and that treatment with a specific mitoNEET ligand (NL1), is neuroprotective following TBI. The proposed experiments are designed to elucidate the mechanism(s) by which pioglitazone confers neuroprotection following TBI by testing the novel hypothesis that pioglitazone, via mitoNEET interaction directly ameliorates mitochondrial dysfunction. To test this hypothesis we propose three specific aims that include the use of multiple innovative tools and techniques that we have in hand, specifically the use of mitoNEET null transgenic mice, a novel mitoNEET ligand (NL-1) and antagonist (NL-3). In Specific Aim 1, we will determine the optimal dosage and therapeutic window of opportunity for pioglitazone to maintain mitochondrial homeostasis post-injury. These measurements will, for the first time, measure mitochondrial dysfunction from synaptic and nonsynaptic mitochondria in the injury core and penumbra from a single animal. In Specific Aim 2 will measure the degree of cortical sparing and behavior improvements that are mediated through pioglitazone treatment after TBI using the optimal dosage determined in Specific Aim 1. In this aim we will use T2 weighted and DTI MRI to longitudinally assess changes in cortical and hippocampal morphology at -3, 3, 7, 14, 28, and 168 days post-injury followed by unbiased stereology at 168 days post-injury. Additionally we will measure acute motor, serial cognitive functional testing and aggressive behavioral function and fear conditioning (chronic measurements of PTSD) to assess the degree of functional recovery as a result of treatment. Specific Aim 3 will determine the mechanism by which pioglitazone affords neuroprotection by testing the hypothesis that pioglitazone's therapeutic effect is mediated through interactions with mitoNEET. This aim will employ the use of transgenic mitoNEET null mice in tandem with a novel mitoNEET specific ligand (NL-1) and mitoNEET antagonist (NL-3). Mitochondrial bioenergetics will be measured at 24 hours and behavioral outcome and tissue sparing will be measured following TBI. The results of these studies will not only shed light on the fundamental processes involved in TBI neuropathology they also move forward the repurposing of an FDA compound for the treatment of TBI and the proposed experiments may pinpoint potential novel targets for the treatment of TBI and perhaps, other neuronal injuries.