Hyperactive PI3Kinase delta enables long distance regeneration of the rat corticospinal tract
Hyperactive PI3Kinase delta enables long distance regeneration of the rat corticospinal tract
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高度活跃的 PI3 激酶 delta 能够实现大鼠皮质脊髓束的远距离再生
DOI：
10.1101/2023.10.27.564182
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Karova K
中科院分区：
文献类型：
--
作者：
Karova K
中枢神经系统神经元的成熟导致其内在再生潜力的丧失。特别是在成人脊髓损伤后，控制步态和精细运动的皮质脊髓轴突的再生很少。先前的研究表明，敲低 PTEN 来增加 PIP3 水平可以促进幼年动物的再生，但对成年动物的影响要小得多，这可能是由于 PIP3 产量较低。在这里，我们用高度活跃的 PI3K、PI3K&δ 转导了感觉运动皮层神经元，这增加了成熟神经元中的 PIP3。这使得皮质神经元能够再生皮质脊髓轴突并改善行为结果。我们在成年大鼠中使用了 C4 背柱损伤模型，并在 4 个部位同时注射了 AAV1-PIK3CD 和 AAV1-eGFP 的混合物或仅滴度匹配的 AAV1-eGFP 混合物。我们让老鼠存活了 6、9、12 或 16 周。免疫染色显示皮质神经元中有 70 - 80% 的共表达，在 12 周和 16 周时均保持稳定。我们对 20μm 脊髓切片中 GFP 标记的轴突进行了计数。在 PI3KCD 处理的动物中，发现许多轴突在病变边缘周围再生，聚集成轴突结，在尾端具有典型的再生外观。沿着脊髓追踪，排除可能来自未病变腹侧 CST 的轴突和神经突，我们发现轴突延伸至病变下方 1 厘米，数量随着距病变距离的增加而减少。 16 周后，病变尾端出现约 200 个轴突，再生指数为 0.2，12 周时这一数字减半。 16 周的行为测试显示，与仅使用 GFP 的对照组相比，接受 PIK3CD 治疗的大鼠在熟练的爪子触及、握力和梯级行走方面都有所改善。除了行为测试之外，PIK3CD 治疗的大鼠的功能恢复也通过电生理记录得到证实，在此期间我们刺激了右侧金字塔。与仅 GFP 对照、仅病变对照和未受伤假手术组相比，病变上方和下方的脊髓背电位 (CDP) 和 EMG 前爪远端屈肌显示出显着增加的连接性。我们得出的结论是，强制皮质神经元中 PI3K&δ 的上调会导致脊髓损伤后的强劲再生，从而导致功能恢复。
Maturation of central nervous system neurons leads to loss of their intrinsic regeneration potential. In particular after injury of the adult spinal cord there is minimal regeneration of corticospinal axons, which control gait and fine movement. Previous work has shown that knockdown of PTEN to increase PIP3 levels can promote regeneration in young animals, but the effect is much less in adults probably due to low PIP3 production. Here, we have transduced sensorimotor cortex neurons with a hyperactive form of PI3K, PI3K&[delta], which increases PIP3 in mature neurons. This enables cortical neurons to regenerate corticospinal axons and improve behavioural outcomes.We used a C4 dorsal column lesion model in adult rats and injected the right motor cortex at 4 sites concurrently with a mixture AAV1-PIK3CD and AAV1-eGFP or titre matched AAV1-eGFP only. We allowed rats to survive for 6, 9, 12 or 16 weeks. Immunostaining showed 70 - 80% co-expression in cortical neurons which remained stable at both 12 and 16 weeks. We counted GFP labelled axons in 20 &[mu]m spinal cord sections. In PI3KCD-treated animals many axons were seen to have regenerated around the margins of lesions, collecting into a knot of axons with the typical appearance of regeneration at the caudal end. Tracing down the cord, and excluding axons and neurites that could have come from unlesioned ventral CST, we found axons extending up to 1 cm below lesions, numbers decreasing with distance from the lesion. After 16 weeks there were circa 200 axons at the caudal end of lesions with a regeneration index of 0.2, with half this number at 12 weeks. Behavioural testing for 16 weeks revealed functional improvements in skilled paw reaching, grip strength and ladder rung walking in rats treated with PIK3CD compared to GFP only controls. In addition to behavioural testing, functional recovery of PIK3CD treated rats was confirmed with electrophysiological recordings during which we stimulated the right pyramid. Cord dorsum potentials (CDPs) above and below lesion and EMG forepaw distal flexor muscles showed greatly increased connectivity compared with GFP only controls, lesion only controls and uninjured shams. We conclude that forcing upregulation of PI3K&[delta] in cortical neurons leads to robust regeneration after spinal cord injury that results in functional restoration.
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影响因子：
29
作者：
Han, Qi;Xie, Yuxiang;Xu, Xiao-Ming
通讯作者：
Xu, Xiao-Ming
体内小鼠中枢神经系统中已确定的神经通路的传导特性
DOI：
--
发表时间：
2004
期刊：
Neurosci Res 49
影响因子：
--
作者：
Tanaka H;et. al.
通讯作者：
et. al.
影响因子：
8.8
作者：
Geoffroy CG;Hilton BJ;Tetzlaff W;Zheng B
通讯作者：
Zheng B
影响因子：
5.9
作者：
Leibinger, Marco;Hilla, Alexander M.;Fischer, Dietmar
通讯作者：
Fischer, Dietmar