京尼平苷酸通过稳定微管促进脊髓损伤后轴突生长

Geniposidic Acid Enhances Axonal Regeneration after Spinal Cord Injury by Stablilizing Microtubule

脊髓损伤(spinal cord injury,SCI)是中枢神经系统最严重的创伤之一,其可造成患者感觉和运动功能障碍,并且引发一系列严重的并发症。促进轴突再生是修复脊髓损伤后功能恢复的关键因素。京尼平苷酸(geniposidic acid,GA)具有神经保护作用,但其在脊髓损伤后轴突生长的作用及机制方面尚未见报道。本研究通过提取原代神经元,并建立糖氧剥夺模型(oxygen glucose deprivation,OGD)。通过RT-PCR、Western印迹、免疫荧光等方法,探讨GA对神经元轴突的促进作用及其机制。结果发现,GA可以显著促进神经元轴突生长,并呈剂量依赖性。与OGD组神经元轴突长度(22±5. 788μm)相比,给予10μmol/L的GA可使神经元轴突长度显著增加(68±17. 73μm)。同时,轴突生长相关蛋白(GAP43,MAP2)的基因和蛋白质水平都显著上升。不仅如此,我们发现,GA促进轴突生长与稳定神经元轴突微管相关,可使A/T的比值增加约1. 5倍。同时,通过建立大鼠急性脊髓损伤模型评价GA在体内的效果,与对照组相比,每天腹腔注射GA(10 mg/kg)的大鼠在术后28 d的BBB评分(11. 8分)和斜板试验(41. 7°)均显著增高。上述结果表明,GA可能通过稳定微管从而促进轴突再生,最终促进脊髓损伤后运动功能的恢复。因此,GA可能成为治疗脊髓损伤的有前景的候选药物。

Spinal cord injury(SCI)is one of the most devastating diseases in the central nervous system that causes sensory and motor dysfunction and a series of severe complications.Promoting axonal regeneration plays a crucial role in locomotor recovery after SCI.Geniposidic acid(GA)has a good neuroprotective effect,however,its effect and mechanism in axonal growth after SCI remains unreported.In vitro,we established oxygen glucose deprivation(OGD)model in primary cortical neurons.The effect and molecular mechanism of GA on neuronal axon was studied by RT-PCR,Western blotting and immunofluorescence analysis.The results showed that GA could markedly promote axonal regeneration in a dose-dependent manner.Compared with the axon length of the OGD group(22±5.788μm),administration of 10μmol/L of GA significantly increased the length of neuronal axon(68±17.73μm).At the same time,the mRNA and protein levels of axon growth-associated proteins(GAP43,MAP2)increased significantly.Furthermore,we found that GA facilitated axonal regeneration and was associated with regulating the stability of microtubule and increasing the A/T ratio by approximately 1.5 times.In this study,we evaluated the effect of GA in vivo by establishing a rat model of acute SCI.Compared to the sham group,rats with intraperitoneal injection of GA(10 mg/kg/day)had a significant increase in BBB score(11.8 points)and the inclined plate test(41.7°)at 28 days postoperatively.These results suggest that GA may facilitate axonal regeneration by improving microtubule stability,ultimately improve functional recovery after SCI.GA may therefore be a promising candidate for the treatment of spinal cord injury.