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

描述（由申请人提供）：这是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种潜在的关键受体——钙透性AMPA受体（CP-AMPAR），它出现在机械损伤后的神经元中，并在神经元死亡中起关键作用。在这个BRP的最后阶段，我们定义了调节CP- ampar出现的机制（目标1），确定了CP- ampar激活何时导致神经元死亡（目标2），并开发了逆转由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用现有化合物测试的策略，以及利用独特技术开发的针对导致神经元死亡的关键分子事件的新疗法。我们的主要假设是(a)损伤后由于AMPAR亚基翻译的改变、GluR2 mRNA编辑的改变以及ERK介导的GluR1同源AMPAR的插入而导致cp -AMPAR增加。(b)立即或延迟抑制钙透性ampar可减少机械损伤后神经元的死亡，其作用增强，恢复G^luR2编辑（calpain抑制）或抑制ERK磷酸化，(c)恢复GluR2 mRNA的ADAR2编辑活性，限制GluR2合成，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。我们评估了损伤后单个树突内转录因子（Elk-1）信号传导和CP- AMPAR亚基的合成/调控，测量了单个神经元和切片培养中RNA编辑和转录的变化，并在TBI动物模型中测试了新开发的治疗方法。相关性：本工作研究了创伤性脑损伤后导致细胞死亡的因素。研究人员测试了使用市售化合物减少神经元死亡的治疗方法，并设计了可能更有效地减少细胞死亡的新分子。这两种治疗方法都要在受伤后立即或几小时内进行有效性测试，这对于了解这些治疗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.