BRP: Molecular Expression of Force Transmission in the Central Nervous System

描述（由申请人提供）：这是一个生物工程研究伙伴关系（BRP）资助的竞争延续，重点是创伤性脑损伤（TBI）的分子机制。我们在最后阶段的工作指出了一个潜在的关键受体-钙渗透性AMPA受体（CP-AMPAR）-出现在神经元机械损伤后，并在神经元死亡中起着关键作用。在该BRP的最后阶段，我们定义了调节CP-AMPAR出现的机制（目标1），确定CP-AMPAR激活何时导致神经元死亡（目标2），并开发用于逆转由CP-AMPAR引发的神经元死亡的疗法（目标3）。我们的治疗方法包括我们可以立即使用可用化合物进行测试的策略，以及使用独特技术开发的新疗法，以靶向导致神经元死亡的关键分子事件。我们的假设是：（a）损伤后CP-AMPAR增加是由于AMPAR亚基翻译的变化、GluR 2 mRNA编辑的变化和ERK介导的GluR 1同源AMPAR插入。(b)立即或延迟抑制钙渗透性AMPAR减少机械损伤后的神经元死亡，并且它们的作用增强，恢复GluR 2编辑（钙蛋白酶抑制）或抑制ERK磷酸化。（c）恢复GluR 2 mRNA的ADAR 2编辑活性，限制GluR 2合成，以及选择性地中断树突中的Elk-1信号传导是改善损伤后神经元存活的有效延迟策略。.我们整合了BRP实验室的集体专业知识，在亚细胞、细胞和器官尺度上测试这些假设。我们评估转录因子（Elk-1）信号传导和损伤后单个树突内CP-AMPAR亚基的合成/调节，测量单个神经元内和切片培养中RNA编辑和转录的变化，并在TBI动物模型中测试新开发的疗法。相关性：这项工作研究了创伤性脑损伤后导致细胞死亡的因素。研究人员使用市售化合物测试减少神经元死亡的治疗方法，并设计出可能在减少细胞死亡方面更有效的新分子。如果在受伤后立即或几个小时内给予，这两种治疗方法的有效性都得到了测试，这对于了解这些方法将来是否会在临床上使用至关重要。

DESCRIPTION (provided by applicant): This is a competing continuation of a Bioengineering Research Partnership (BRP) grant focusing on the molecular mechanisms of traumatic brain injury (TBI). Our work in the last phase points out a potentially critical receptor - the calcium permeable AMPA receptor (CP-AMPAR) - that appears in neurons after mechanical injury and plays a key role in neuronal death. In the final phase of this BRP, we define the mechanisms regulating the appearance of CP-AMPARs (Aim 1), determine when CP-AMPAR activation leads to neuronal death (Aim 2), and develop therapies for reversing neuronal death initiated by CP- AMPARs (Aim 3). Our therapeutic approaches include strategies we can test immediately with available compounds, as well as new therapies developed with unique technologies to target key molecular events that lead to neuronal death. Our overlying hypotheses are (a) CP-AMPARs increase following injury due a change in the translation of AMPAR subunits, a change in the editing of GluR2 mRNA, and an ERK mediated insertion of GluR1 homomeric AMPARs. (b) Immediate or delayed inhibition of calcium permeable AMPARs reduce neuronal death after mechanical injury, and their effect is enhanced restoring G^luR2 editing (calpain inhibition) or inhibiting ERK phosphorylation, (c) Restoring ADAR2 editing activity of GluR2 mRNA, limiting the GluR2 synthesis, and interrupting Elk-1 signaling selectively in dendrites are effective delayed strategies to improve neuronal survival after injury. . We integrate the collective expertise of the BRP labs to test these hypotheses across the subcellular, cellular and organ scale. We evaluate transcription factor (Elk-1) signaling and the synthesis/regulation of CP- AMPAR subunits within individual dendrites after injury, measure changes in RNA editing and transcription within individual neurons and in slice culture, and test newly developed therapies in animal models of TBI. Relevance: This work studies factors that cause cell death after traumatic brain injury. The investigators test treatments to reduce neuronal death using commercially available compounds, and design new molecules that may be even more effective in reducing cell death. Both treatment approaches are tested for their effectiveness if given either immediately or several hours after injury, which is critical to know if these will be used clinically in the future.