BDNF/TrkB/小G蛋白对脊髓耐受性的影响及参芪麝蓉丸的调控作用研究

Spinal cord, that adapted to the compression of intervertebral discs and vertebral osteophyte, with slight, or even without clinical symptoms, is called “spinal cord tolerance”. It is the key to the onset of the cervical spondylotic myelopathy (CSM). The chronic compression of spinal cord could induce stress products, then activate the BDNF/TrkB through the PI3K/Akt, PLC/PKC, small G-protein (Ras/Raf)/MEK/ERK signal pathway, to promote neuronal survival, and improve the plasticity of structure and function of neuron, it is an important mechanism for promoting spinal cord ischemia and hypoxia tolerance. The project team had found that the Arf-like protein 5b (Arl5b) from the small G-protein family is a risk gene for the CSM. The efficacy of the Shenqisherong Pill for CSM has been confirmed, and it could increase the expression of BNDF, promote the recovery of neurological function. We will propose idiopathic CSM twy mice and hydrogel-induced chronic spinal cord compression rats, apply immunohistochemistry, Western Blot, Real time RT PCR to detect the signal molecules, and observe the regulation of the BDNF/TrkB/ small G-protein (Arl5b, Ras and Raf) for the spinal cord tolerance, and reveal the pathogenesis of CSM, and the mechanism Shenqisherong Pill to improve of the spinal cord tolerance to treat CSM.

脊髓适应和抵抗压迫（脊髓耐受性）是脊髓型颈椎病（CSM）发病的关键。慢性压迫刺激脊髓，激活BDNF/TrkB及下游PI3K/Akt、PLC/PKC、小G蛋白（Ras/Raf/Rap1）/MEK/ERK信号通路，促进神经元存活、提高结构与功能可塑性，是促进脊髓耐受缺血缺氧的重要机制。项目组发现小G蛋白家族Arl5b是CSM的危险基因，故提出BDNF和TrkB调节小G蛋白（Arl5b、Rap1），是脊髓耐受性的关键作用通路。参芪麝蓉丸改善CSM疗效明确，能增加BNDF表达，促进神经功能恢复。我们拟用自发性CSM的twy小鼠和水凝胶缓慢压迫脊髓的大鼠CSM模型，采用免疫组化、Western Blot、Real time RT-PCR等实验方法检测上述信号分子，观察BDNF/TrkB/小G蛋白（Arl5b、Rap1）对脊髓耐受性的调控效应，揭示CSM发病及参芪麝蓉丸提高脊髓耐受性治疗CSM的机制。

脊髓适应和抵抗压迫（脊髓耐受性）是脊髓型颈椎病（CSM）发病的关键。慢性压迫刺激脊髓，激活BDNF/TrkB及下游PI3K/Akt、PLC/PKC、小G蛋白（Ras/Raf/Rap1）/MEK/ERK信号通路，促进神经元存活、提高结构与功能可塑性，是促进脊髓耐受缺血缺氧的重要机制。项目组发现小G蛋白家族Arl5b是CSM的危险基因，故提出BDNF和TrkB调节小G蛋白（Arl5b、Rap1），是脊髓耐受性的关键作用通路。参芪麝蓉丸改善CSM疗效明确，能增加BNDF表达，促进神经功能恢复。.我们用水凝胶缓慢压迫脊髓的大鼠CSM模型，采用免疫组化、Western Blot、Real time RT-PCR等实验方法检测上述信号分子。HE 染色显示，模型组受压颈髓组织可见炎症带、出血和大量中性粒细胞浸润， 神经元大量坏死，形成脊髓空洞，脊髓组织结构遭破坏；而参芪麝蓉丸干预后，能 有效抑制脊髓组织水肿和变性，减少中性粒细胞浸润、神经元坏死和脊髓空洞数量， 受压颈髓组织区域结构改善。免疫荧光染色和Western blot 显示，模型组大鼠受压部位BDNF、TrkB 和NeuN、Bcl-2 表达显著下调，Cleaved Caspase-3、Bax 表达显著升高；与模型组比较，参芪麝蓉丸组的 BDNF、TrkB 和 NeuN、Bcl-2 表达明显升高，Cleaved Caspase-3、Bax 表达明显降低。TUNEL 染色显示，与模型组比较，参芪麝蓉丸组颈髓压迫部位的神经元细胞凋亡少，NeuN 阳性细胞数量有一定程度增加。初步揭示了参芪麝蓉丸提高脊髓耐受性治疗脊髓型颈椎病的机制。