In vivo transduction of neurons with TAT-UCH-L1 protects brain against controlled cortical impact injury.
In vivo transduction of neurons with TAT-UCH-L1 protects brain against controlled cortical impact injury.
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DOI：
10.1371/journal.pone.0178049
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Graham SH
中科院分区：
文献类型：
--
作者：
Liu H;Rose ME;Ma X;Culver S;Dixon CE;Graham SH
创伤后继发性脑损伤的发生与多种机制或途径有关，如泛素-蛋白酶体途径（UPP）、轴突变性和神经细胞凋亡等。UCH-L1是一种在神经元中高水平表达的蛋白质，可能在UPP、自噬和轴突完整性中起重要作用。本研究旨在评估UCH-L1在创伤后脑损伤（TBI）中的作用及其潜在的治疗作用。将反式激活转导（达特）蛋白的蛋白转导结构域（PTD）与UCH-L1融合，构建了一种新的促进神经元转导的蛋白（TAT-UCH-L1）。小鼠腹腔内给药后，通过免疫印迹和免疫组织化学在脑中容易检测到TAT-UCH-L1蛋白。使用受控皮质撞击（CCI）模型在小鼠中诱导TBI。与溶剂对照组相比，TAT-UCH-L1治疗显著减弱CCI后海马中K48-连接的聚泛素（polyUb）-蛋白的积累，但对K65-连接的polyUb-蛋白没有影响。TAT-UCH-L1治疗也减弱CCI后Beclin-1和LC 3BII的表达。TAT-UCH-L1处理的小鼠与对照溶剂处理的小鼠相比，CCI后21天的备用组织体积显著增加，CA 3神经元存活率增加。在TAT-UCH-L1处理的小鼠中，CCI后24 h和21 d，通过APP免疫组织化学检测的丘脑轴突损伤减少。这些结果表明，TAT-UCH-L1治疗改善了UPP的功能，并降低了CCI后自噬的激活。此外，TAT-UCH-L1治疗还减轻了CCI后的轴突损伤并增加了海马神经元存活。总之，这些结果表明，UCH-L1可能在TBI后细胞死亡和轴突损伤的发病机制中发挥重要作用。
Many mechanisms or pathways are involved in secondary post-traumatic brain injury, such as the ubiquitin-proteasome pathway (UPP), axonal degeneration and neuronal cell apoptosis. UCH-L1 is a protein that is expressed in high levels in neurons and may have important roles in the UPP, autophagy and axonal integrity. The current study aims to evaluate the role of UCH-L1 in post-traumatic brain injury (TBI) and its potential therapeutic effects. A novel protein was constructed that fused the protein transduction domain (PTD) of trans-activating transduction (TAT) protein with UCH-L1 (TAT-UCH-L1) in order to promote neuronal transduction. The TAT-UCH-L1 protein was readily detected in brain by immunoblotting and immunohistochemistry after i.p. administration in mice. TBI was induced in mice using the controlled cortical impact (CCI) model. TAT-UCH-L1 treatment significantly attenuated K48-linkage polyubiquitin (polyUb)-protein accumulation in hippocampus after CCI compared to vehicle controls, but had no effects on K65-linkage polyUb-protein. TAT-UCH-L1 treatment also attenuated expression of Beclin-1 and LC3BII after CCI. TAT-UCH-L1-treated mice had significantly increased spared tissue volumes and increased survival of CA3 neurons 21 d after CCI compared to control vehicle-treated mice. Axonal injury, detected by APP immunohistochemistry, was reduced in thalamus 24 h and 21 d after CCI in TAT-UCH-L1-treated mice. These results suggest that TAT-UCH-L1 treatment improves function of the UPP and decreases activation of autophagy after CCI. Furthermore, TAT-UCH-L1 treatment also attenuates axonal injury and increases hippocampal neuronal survival after CCI. Taken together these results suggest that UCH-L1 may play an important role in the pathogenesis of cell death and axonal injury after TBI.