Targeted delivery of TrkB receptor to phrenic motoneurons enhances functional recovery of rhythmic phrenic activity after cervical spinal hemisection.
Targeted delivery of TrkB receptor to phrenic motoneurons enhances functional recovery of rhythmic phrenic activity after cervical spinal hemisection.
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DOI：
10.1371/journal.pone.0064755
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Mantilla CB
中科院分区：
文献类型：
--
作者：
Gransee HM;Zhan WZ;Sieck GC;Mantilla CB
在C2（SH）处单侧前外侧索横断的脊髓半切后，随着时间的推移，节律性膈神经活动逐渐恢复。脑源性神经营养因子（BDNF）通过其全长原肌球蛋白相关激酶受体亚型B（Trk B.FL）参与脊髓损伤后的神经可塑性，但其具体的细胞底物尚不清楚。我们假设，选择性靶向增加TrkB.FL表达的膈运动神经元将足以提高恢复后SH的节律性膈活动。筛选了几种表达GFP的腺相关病毒（AAV）血清型，以确定通过胸膜内注射在成年大鼠中进行膈运动神经元转导的特异性。在用AAV血清型7、8和9治疗后3周，在颈脊髓中存在GFP表达，但用AAV 2、6或恒河猴-10治疗后不存在。总体而言，AAV 7在膈运动神经元中产生最一致的GFP表达。在胸膜内注射表达人TrkB.FL-FLAG的AAV 7或盐水后3周进行SH。通过膈运动核中的FLAG蛋白表达和显微切割的膈运动神经元中的人TrkB.FL mRNA表达来证实TrkB.FL-FLAG向膈运动神经元的递送。在所有SH大鼠中，在SH后3天证实了同侧膈肌EMG活动的缺乏，验证了同侧膈运动神经元下行驱动的完全中断。在SH后14天，与8只未处理的SH大鼠中的3只相比，所有AAV 7-TrkB.FL处理的大鼠（n = 11）显示出同侧膈肌EMG活性的恢复（p<0.01）。 在正常呼吸期间，AAV 7-TrkB.FL处理的大鼠表现出73±7%的SH前均方根EMG，而未处理的SH大鼠仅为31±11%，显示出恢复（p<0.01）。这项研究提供了直接的证据表明，增加TrkB.FL在膈运动神经元的表达是足够的，以提高恢复同侧的节律性膈活动后SH，表明选择性靶向基因表达备用运动神经元低于脊髓损伤的水平，可能会促进功能恢复。
Progressive recovery of rhythmic phrenic activity occurs over time after a spinal cord hemisection involving unilateral transection of anterolateral funiculi at C2 (SH). Brain-derived neurotrophic factor (BDNF) acting through its full-length tropomyosin related kinase receptor subtype B (TrkB.FL) contributes to neuroplasticity after spinal cord injury, but the specific cellular substrates remain unclear. We hypothesized that selectively targeting increased TrkB.FL expression to phrenic motoneurons would be sufficient to enhance recovery of rhythmic phrenic activity after SH. Several adeno-associated virus (AAV) serotypes expressing GFP were screened to determine specificity for phrenic motoneuron transduction via intrapleural injection in adult rats. GFP expression was present in the cervical spinal cord 3 weeks after treatment with AAV serotypes 7, 8, and 9, but not with AAV2, 6, or rhesus-10. Overall, AAV7 produced the most consistent GFP expression in phrenic motoneurons. SH was performed 3 weeks after intrapleural injection of AAV7 expressing human TrkB.FL-FLAG or saline. Delivery of TrkB.FL-FLAG to phrenic motoneurons was confirmed by FLAG protein expression in the phrenic motor nucleus and human TrkB.FL mRNA expression in microdissected phrenic motoneurons. In all SH rats, absence of ipsilateral diaphragm EMG activity was confirmed at 3 days post-SH, verifying complete interruption of ipsilateral descending drive to phrenic motoneurons. At 14 days post-SH, all AAV7-TrkB.FL treated rats (n = 11) displayed recovery of ipsilateral diaphragm EMG activity compared to 3 out of 8 untreated SH rats (p<0.01). During eupnea, AAV7-TrkB.FL treated rats exhibited 73±7% of pre-SH root mean squared EMG vs. only 31±11% in untreated SH rats displaying recovery (p<0.01). This study provides direct evidence that increased TrkB.FL expression in phrenic motoneurons is sufficient to enhance recovery of ipsilateral rhythmic phrenic activity after SH, indicating that selectively targeting gene expression in spared motoneurons below the level of spinal cord injury may promote functional recovery.
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影响因子：
6.1
作者：
Dougherty, KD;Dreyfus, CF;Black, IB
通讯作者：
Black, IB
影响因子：
5.3
作者：
Coumans, JV;Lin, TTS;Bregman, BS
通讯作者：
Bregman, BS
影响因子：
5.3
作者：
King, VR;Bradbury, EJ;Priestley, JV
通讯作者：
Priestley, JV
DOI：
10.1073/pnas.89.23.11282
发表时间：
1992-12-01
影响因子：
11.1
作者：
FRISEN, J;VERGE, VMK;RISLING, M
通讯作者：
RISLING, M
影响因子：
5.3
作者：
Golder, FJ;Mitchell, GS
通讯作者：
Mitchell, GS