交通医学

目的：探讨人参皂苷Rg1联合跑台训练抑制大鼠脊髓损伤（spinal cord injury,SCI）后内侧前额叶皮层（medial prefrontal cortex,mPFC）及海马神经炎症反应机制。方法：取SD大鼠90只，随机分为Sham组、SCI组、SCI+生理盐水组、SCI+人参皂苷Rg1组、SCI+跑台训练组及SCI+跑台训练+人参皂苷Rg1组（每组15只）。采用精密脊髓损伤撞击器建立SCI模型，依据组别给予腹腔注射人参皂苷Rg1、大鼠跑台训练，术后14天取大鼠mPFC及海马组织，采用BBB量表评估各组大鼠后肢运动功能，q-PCR检测海马组织小胶质细胞及星形胶质细胞标志物mRNA表达水平，免疫荧光法检测mPFC组织小胶质细胞数量，q-PCR检测海马组织Caspase-3/Bcl-2 mRNA表达水平，酶联免疫吸附法检测mPFC及海马组织中促炎因子水平。结果：SCI组BBB评分较Sham组明显降低，SCI+人参皂苷Rg1+跑台训练组BBB评分较SCI组明显提升（均P<0.05）。q-PCR检测结果显示，SCI组、SCI+生理盐水组Iba-1、GFAP mRNA表达水平高于Sham组（均P<0.05）;SCI+跑台训练+人参皂苷Rg1组Iba1、GFAP mRNA表达水平高于Sham组，但低于SCI组、SCI+人参皂苷Rg1组和SCI+跑台训练组（均P<0.05）。免疫荧光法检测结果显示，SCI组、SCI+生理盐水组Iba-1阳性细胞较Sham组增多（均P<0.05）;SCI+跑台训练+Rg1组Iba-1阳性细胞多于Sham组，但少于SCI组、SCI+人参皂苷Rg1组、SCI+跑台训练组（均P<0.05）。SCI组及SCI+生理盐水组Caspase-3、Bcl-2 mRNA表达水平显著高于Sham组（均P<0.05）;SCI+人参皂苷Rg1组、SCI+跑台训练组Caspase-3、Bcl-2 mRNA表达水平较SCI组显著降低（均P<0.05）；而SCI+跑台训练+人参皂苷Rg1组Caspase-3、Bcl-2 mRNA表达水平进一步降低，但与SCI+人参皂苷Rg1组、SCI+跑台训练组的差异均无统计学意义（P>0.05）。SCI组、SCI+生理盐水组mPFC组织及海马组织内TNF-α、IL-1及IL-6水平高于Sham组（均P<0.05）;SCI+跑台训练+人参皂苷Rg1组TNF-α、IL-1及IL-6水平高于Sham组（均P<0.05），但低于SCI组、SCI+生理盐水组、SCI+人参皂苷Rg1组和SCI+跑台训练组（均P<0.05）。结论：跑台训练与人参皂苷Rg1联合干预，可通过调控胶质细胞活化状态，抑制神经细胞凋亡，并显著减轻mPFC及海马组织的神经炎症反应。

Objective: To investigate the mechanism by which ginsenoside Rg1 combined with treadmill training in inhibiting neuroinflammatory responses in the medial prefrontal cortex(mPFC) and hippocampus after spinal cord injury(SCI) in rats. Methods: A total of 90 SD rats were randomly assigned to the Sham group, the SCI group, the SCI+normal saline group, the SCI +ginsenoside Rg1 group, the SCI +treadmill training group, and the SCI +treadmill training +ginsenoside Rg1 group(n =15 per group). An SCI model was established using a precision spinal cord impactor. Based on group assignment, rats received intraperitoneal injection of ginsenoside Rg1 and treadmill training. After 14 days, the mPFC and hippocampal tissues of rats were collected. The hindlimb motor function of rats in each group was assessed using the BBB scale. q-PCR was used to detect mRNA expression levels of microglial and astrocytic markers in hippocampal tissue.Immunofluorescence was employed to determine the number of microglia in mPFC tissue. q-PCR was also performed to measure Caspase-3/Bcl-2 mRNA expression levels in hippocampal tissue, while enzyme-linked immunosorbent assay(ELISA) was used to detect pro-inflammatory cytokine levels in both mPFC and hippocampal tissues. Results: The BBB scores in the SCI group were significantly lower than those in the Sham group, while the BBB scores in the SCI+Rg1+treadmill training group were significantly higher than those in the SCI group(all P<0.05). q-PCR results showed that the expression levels of Iba-1 and GFAP mRNA in the SCI group and the SCI+saline group were higher than those in the Sham group(all P<0.05); the expression levels of Iba-1 and GFAP mRNA in the SCI+treadmill exercise+ginsenoside Rg1 group were higher than those in the Sham group, but lower than those in the SCI group, SCI+ginsenoside Rg1 group, and SCI+treadmill training group(all P<0.05). The results of the immunofluorescence assay showed that the number of Iba-1 positive cells in the SCI group and the SCI + normal saline group was higher than that in the Sham group(all P<0.05); the number of Iba-1 positive cells in the SCI + treadmill exercise + Rg1 group was more than that in the Sham group, but less than that in the SCI group, the SCI + Rg1 group, and the SCI + treadmill training group(all P<0.05). The expression levels of Caspase-3 and Bcl-2 mRNA in the SCI group and the SCI + normal saline group were significantly higher than those in the Sham group(all P<0.05); the expression levels of Caspase-3 and Bcl-2 mRNA in the SCI + ginsenoside Rg1 group and the SCI + treadmill training group were significantly lower than those in the SCI group(all P<0.05); while the expression levels of Caspase-3 and Bcl-2 mRNA in the SCI + treadmill exercise + ginsenoside Rg1 group further decreased, and there were no statistically significant differences compared with the SCI + ginsenoside Rg1 group and the SCI + treadmill training group(P>0.05). The levels of TNF-α, IL-1 and IL-6 in the mPFC and hippocampus tissues of the SCI group and the SCI +normal saline group were higher than those in the Sham group(all P<0.05); the levels of TNF-α, IL-1 and IL-6 in the SCI +treadmill exercise + ginsenoside Rg1 group were higher than those in the Sham group(all P<0.05), but lower than those in the SCI group, the SCI + normal saline group, the SCI + ginsenoside Rg1 group and the SCI + treadmill training group(all P <0.05). Conclusion: The combined intervention of treadmill training and ginsenoside Rg1 can inhibit the apoptosis of nerve cells by regulating the activation state of glial cells, and significantly reduce the inflammatory response in the mPFC and hippocampal tissues.