Silencing of PHLPP1 promotes neuronal apoptosis and inhibits functional recovery after spinal cord injury in mice
Silencing of PHLPP1 promotes neuronal apoptosis and inhibits functional recovery after spinal cord injury in mice
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PHLPP1沉默促进小鼠脊髓损伤后神经元凋亡并抑制功能恢复
DOI：
10.1016/j.lfs.2018.08.030
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发表时间：
2018-09-15
期刊：
影响因子：
6.1
通讯作者：
Mei, Xifan
中科院分区：
文献类型：
--
作者：
Shao, Zhenya;Lv, Gang;Mei, Xifan
目的：脊髓损伤(SCI)引起神经细胞凋亡增加，导致脊髓不可逆性功能障碍。在本研究中，我们研究了Pleckstrin同源(PH)结构域和富亮氨酸重复蛋白磷酸酶1(PHLPP1)基因沉默后对脊髓损伤进展和细胞凋亡的影响。主要方法：脊髓注射和携带针对PHLPP1的小干扰RNA(SiRNA)的重组腺病毒载体(AdsiPHLPP1)成功地沉默PHLPP1。分别在体内和体外建立了PHLPP1沉默的模型，使转基因在神经元中稳定表达。关键发现：结果表明，沉默PHLPP1明显降低了脊髓损伤后核因子红系2相关因子2(Nrf2)的水平。Western印迹分析显示，注射AdsiPHLPP1的小鼠在体内和体外均表现出促凋亡因子(Bax和裂解半胱氨酸天冬氨酸蛋白酶3)的表达增加，神经营养因子(BDNF)和抗凋亡因子(Bcl-2)的水平降低。注射AdsiPHLPP1的小鼠运动功能恢复较野生型(WT)小鼠慢。此外，脊髓损伤后脊髓前角存活的运动神经元数量也减少。意义：我们的结果证实，在体内和体外，沉默PHLPP1促进神经元凋亡，抑制损伤后的功能恢复。因此，PHLPP1基因可能成为临床治疗脊髓损伤的潜在靶向基因。
Aim: Spinal cord injury (SCI) causes increased apoptosis of neurons, leading to irreversible dysfunction of the spinal cord. In this study, we investigated the effects of the progression of SCI and potential regulation of apoptosis after the Pleckstrin homology (PH) domain and leucine rich repeat protein phosphatase 1 (PHLPP1) gene was silenced.Main methods: Spinal cord injection, and neuronal transfection with a recombinant adenovirus vector encoding small interfering RNA (siRNA) against PHLPP1 (AdsiPHLPP1) successfully silenced PHLPP1. These created in vivo and in vitro PHLPP1-silenced models, respectively, resulting in stable expression of the transgene in neurons.Key findings: The results showed that silencing of PHLPP1 evidently reduced levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) after SCI. Western blot analysis revealed that the mice injected with AdsiPHLPP1 showed increased the expression of pro-apoptotic factors (Bax and cleaved-caspase 3), and reduced levels of neurotrophic (BDNF) and anti-apoptotic (Bcl-2) factors, both in vivo and in vitro. The motor function of AdsiPHLPP1-injected mice was restored more slowly than that of wild type (WT) mice. In addition, the number of motor neurons surviving in the anterior horn of the spinal cord was also reduced after SCI.Significance: Our results confirm that silencing of PHLPP1 promotes neuronal apoptosis and inhibits functional recovery after injury in vivo and in vitro. Consequently, PHLPP1 represents a potential therapeutic target gene for the clinical treatment of SCI.