基于BDNF/TrκB信号通路探讨补阳还五汤治疗脊髓损伤的作用机制

Approach to effect and mechanism of Buyang Huanwu decoction on spinal cord injury based on BDNF/TrkB signaling pathway

目的:基于BDNF/TrκB信号通路探讨补阳还五汤治疗脊髓损伤(spinal cord injury,SCI)大鼠的作用机制。方法:制作SCI大鼠模型。将40只大鼠随机分为模型组、中药组、抑制剂组、假手术组4组。每组脊髓损伤大鼠术后连续治疗7天后进行尼氏染色观察脊髓细胞形态,免疫组织化学法检测BDNF的表达,免疫印记法(western blot,WB)检测脊髓组织中BDNF、TrκB以及p-TrκB含量。结果:治疗后,尼氏染色结果显示模型组脊髓组织明显破坏,大量空洞样改变,髓鞘排列散乱;中药组、抑制剂组、假手术组脊髓损伤程度减轻。与模型组比较,中药组、抑制剂组及假手术组脊髓组织中BDNF阳性表达升高(P﹤0.05),尤以中药组中脊髓组织BDNF阳性表达最为显著(P﹤0.05)。与模型组比较,中药组、抑制剂组BDNF、TrκB、p-TrκB的表达显著增加(P﹤0.05),而与假手术组TrκB表达无明显差异(P﹥0.05);与抑制剂组比较,假手术组、中药组p-TrκB表达显著增加(P﹤0.05)。结论:补阳还五汤可以促进大鼠损伤区脊髓组织内BDNF和TrκB以及p-TrκB含量增多,从而达到对脊髓神经元的保护作用。BDNF/TrκB信号通路在补阳还五汤抑制脊髓神经元凋亡、促进脊髓神经元再生的过程中起到了关键作用。

Objective:To approach the effect and mechanism of Buyang Huanwu decoction on spinal cord injury(SCI)based on BDNF/TrκB signaling pathway.Methods:SCI rat model was established.40 rats were randomly divided into four groups:model group,TCM group,inhibitor group and sham-operation group.After the rats with spinal cord injury in each group were treated continuously for 7 days after operation,the morphology of spinal cord cells was observed by Nissl staining.The expression of BDNF was detected by immunohistochemistry.The contents of BDNF,TrκB and p-TrκB in spinal cord tissue were detected by Western blot.Results:After treatment,Nissl staining showed that spinal cord tissue of model group was obviously destroyed,and with a large number of cavitylike changes and scattered arrangement of myelin sheath.The degree of spinal cord injury was reduced in TCM group,inhibitor group and sham-operation group.Compared with the model group,the positive expression of BDNF in spinal cord tissue was increased in TCM group,inhibitor group and sham-operation group(P﹤0.05);especially,the positive expression of BDNF in spinal cord tissue was the most significant in TCM group(P﹤0.05).Compared with the model group,the expressions of BDNF,TrκB and p-TrκB were significantly increased in TCM group and inhibitor group(P﹤0.05),while the expression of TrκB was not significantly different in sham operation group(P﹥0.05);compared with the inhibitor group,the expression of p-TrκB was significantly increased in sham-operation group and TCM group(P﹤0.05).Conclusion:Buyang Huanwu decoction can promote the increment of contents of BDNF,TrκB and p-TrκB in spinal cord tissue in injured area of rats,so as to achieve the protective effect on spinal cord neurons.BDNF/TrκB signaling pathway plays a key role for Buyang Huanwu decoction inhibiting apoptosis of spinal cord neurons and promoting regeneration of spinal cord neurons.