Liu Gang, Deng Bowen, Huo Luyao, Fan Xiao, Bai Huizhong, Zhao Yi, Xu Lin, Gao Feng, Mu Xiaohong
Beijing University of Chinese Medicine, Dongzhimen Hospital, Beijing, 100029, China.
Tsinghua University, Department of Mechanical Engineering, 100084, China.
Eur J Pharmacol. 2024 Aug 15;977:176710. doi: 10.1016/j.ejphar.2024.176710. Epub 2024 Jun 4.
OBJECTIVE: Tetramethylpyrazine (TMP) has been demonstrated to alleviate neuronal ferroptosis following spinal cord injury (SCI), thereby promoting neural repair. However, the precise underlying mechanisms remain elusive. METHODS: The SCI model was established using a modified version of Allen's method. TMP (40, 80, 120, and 160 mg/kg) and ras-selective lethal 3 (RSL3) (5 mg/kg) were administered intraperitoneally once daily for 7 days. HE and Nissl staining were employed to examine histomorphology and neurons, respectively. Perls staining was used to identify the distribution of iron. A transmission electron microscope was used to observe the microcosmic morphology of mitochondria. Immunofluorescence staining and Western blot were used to analyze neuronal nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP) surrounding injury sites. Additionally, glutathione peroxidase 4 (GPX4)/NeuN + cells and acyl-CoA synthetase long-chain family member 4 (ACSL4)/NeuN + cells were observed. RT-qPCR was conducted to examine the mRNA expression levels of GPX4 and ACSL4. ELISA were used to quantify the concentrations of GPX4, reactive oxygen species (ROS), L-glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and tissue iron. RESULTS: TMP had an inhibitory effect on the concentrations of tissue iron, ROS, GSH, MDA, and SOD. TMP improved the microcosmic morphology of mitochondria and increased GPX4 level while decreasing that of ACSL4. TMP reduced lesion sizes, enhanced neuronal survival, and inhibited glial scar formation. However, the effect of TMP can be effectively reversed by RSL3. CONCLUSION: TMP alleviates neuronal ferroptosis by regulating the GPX4/ACSL4 axis, thereby protecting the remaining neurons surrounding injury sites and reducing glial scar formation.
目的:已证实川芎嗪(TMP)可减轻脊髓损伤(SCI)后的神经元铁死亡,从而促进神经修复。然而,其确切的潜在机制仍不清楚。 方法:采用改良的Allen法建立SCI模型。TMP(40、80、120和160mg/kg)和ras选择性致死3(RSL3)(5mg/kg)每天腹腔注射1次,连续7天。分别采用苏木精-伊红(HE)染色和尼氏染色检查组织形态学和神经元。普鲁士蓝染色用于鉴定铁的分布。透射电子显微镜用于观察线粒体的微观形态。免疫荧光染色和蛋白质免疫印迹法用于分析损伤部位周围的神经元核蛋白(NeuN)和胶质纤维酸性蛋白(GFAP)。此外,观察谷胱甘肽过氧化物酶4(GPX4)/NeuN+细胞和酰基辅酶A合成酶长链家族成员4(ACSL4)/NeuN+细胞。采用逆转录-定量聚合酶链反应(RT-qPCR)检测GPX4和ACSL4的mRNA表达水平。酶联免疫吸附测定(ELISA)用于定量GPX4、活性氧(ROS)、L-谷胱甘肽(GSH)、丙二醛(MDA)、超氧化物歧化酶(SOD)和组织铁的浓度。 结果:TMP对组织铁、ROS、GSH、MDA和SOD的浓度有抑制作用。TMP改善了线粒体的微观形态,提高了GPX4水平,同时降低了ACSL4水平。TMP减小了损伤面积,提高了神经元存活率,抑制了胶质瘢痕形成。然而,RSL3可有效逆转TMP的作用。 结论:TMP通过调节GPX4/ACSL4轴减轻神经元铁死亡,从而保护损伤部位周围的剩余神经元,减少胶质瘢痕形成。
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