【目的】 探讨苦参碱通过调节腺苷酸活化蛋白激酶/哺乳动物雷帕霉素靶蛋白/UNC-51样激酶1（AMPK/mTOR/ULK1）通 路对创伤性脑损伤（TBI）大鼠神经元自噬的影响。【方法】 构建TBI大鼠模型并将其随机分为模型组，苦参碱低、中、高剂量 组，苦参碱高剂量＋Metformin（AMPK 激活剂）组，每组 24只。另设假手术组（24只大鼠）。水迷宫试验评估大鼠认知功能， Nissl染色法观察海马组织病理变化，TUNEL法观察海马神经元凋亡情况，透射电镜观察神经元自噬，Western Blot法检测海 马组织p-AMPK、AMPK、p-mTOR、mTOR、p-ULK1、ULK1及自噬相关蛋白Beclin-1和微管相关蛋白1轻链3（LC3）蛋白表 达量。【结果】 与假手术组比较，模型组大鼠认知功能减弱，脑含水量升高，神经元凋亡占比增加，神经元形态不规则，尼 氏体染色变浅，神经元中有较多的溶酶体和自噬体，p-AMPK/AMPK、p-ULK1/ULK1比值及Beclin-1和LC3蛋白表达量显著 增多，p-mTOR/mTOR 比值显著降低（P＜0.05）；与模型组比较，苦参碱低、中、高剂量组大鼠认知功能恢复，脑含水量减 少，神经元形态结构趋于完整，尼氏体染色变深，神经元中的溶酶体和自噬体以及神经元凋亡部分减少，p-AMPK/AMPK、 p-ULK1/ULK1比值及 Beclin-1和 LC3蛋白表达量降低，p-mTOR/mTOR 比值变大（P＜0.05），呈剂量依赖效应；与苦参碱高 剂量组比较，苦参碱高剂量+Metformin组大鼠神经元形态结构破坏、认知功能减弱，脑含水量及神经元凋亡占比增多，自噬 增强，提示Metformin逆转了苦参碱对TBI大鼠神经元自噬的抑制作用。【结论】 苦参碱可通过抑制AMPK/mTOR/ULK1信号通 路，减轻TBI大鼠神经元自噬，改善神经损伤。

Objective To investigate the effects of matrine on neuronal autophagy via the adenosine monophosphateactivated protein kinase/mammalian target of rapamycin/UNC-51 like autophagy activating kinase 1 （AMPK/ mTOR/ULK1） pathway in rats with traumatic brain injury （TBI）. Methods A TBI rat model was established and the modeled rats were randomly divided into the model group，low-，medium-，and high-dose matrine groups， and a high-dose matrine + Metformin （an AMPK activator） group，with 24 rats in each group. In addition，the sham-operation group（24 rats） was set up. The Morris water maze test was employed to assess cognitive function. Pathological changes in hippocampal tissue were observed using Nissl staining. Hippocampal neuronal apoptosis was detected by TUNEL assay. Neuronal autophagy was observed via transmission electron microscopy. Western Blot was used to measure the protein expression levels of p-AMPK， AMPK， p-mTOR， mTOR， p-ULK1， ULK1， the autophagy-related protein Beclin-1， and microtubule-associated protein 1 light chain 3（LC3） in hippocampal tissue. Results Compared with the sham-operation group， the model group showed impaired cognitive function，increased brain water content，increased percentage of neuronal apoptosis，irregular neuronal morphology， lighter Nissl staining， more lysosomes and autophagosomes in neurons， significantly increased ratios of p-AMPK/AMPK and p-ULK1/ULK1， and increased protein expression levels of Beclin-1 and LC3， while the p-mTOR/mTOR ratio was significantly decreased （P＜0.05）. Compared with the model group，the low-， medium- ， and high-dose matrine groups exhibited restored cognitive function， reduced brain water content， more intact neuronal morphology and structure，darker Nissl staining，reduced lysosomes，autophagosomes，and neuronal apoptosis， decreased protein expression ratios of p-AMPK/AMPK and p-ULK1/ULK1， decreased protein expression of Beclin-1 and LC3，and an increased p-mTOR/mTOR ratio （P＜0.05），showing a dosedependent effect. Compared with the high-dose matrine group， the high-dose matrine+Metformin group demonstrated disrupted neuronal morphology and structure， impaired cognitive function， increased brain water content and percentage of neuronal apoptosis，and enhanced autophagy，suggesting that Metformin reversed the inhibitory effect of matrine on neuronal autophagy in TBI rats. Conclusion Matrine can reduce neuronal autophagy， and ameliorate neural damage in TBI rats，potentially by inhibiting the AMPK/mTOR/ULK1 signaling pathway.

R285.5

湖北省自然科学基金项目（编号：2023AFB1051）