灯盏花素对脑外伤大鼠皮质神经元自噬、炎症损伤及TLR4/NF-κB信号通路的影响

Influence of Breviscapine on Autophagy,Inflammatory Damage and TLR4/NF-κB Signaling Pathway in Cortical Neurons of Rats with Traumatic Brain Injury

目的观察灯盏花素对脑外伤大鼠皮质神经元自噬和炎症损伤的影响及其作用机制。方法随机选取10大鼠为假手术组,其余大鼠建立脑外伤模型,造模成功后分为模型组、米诺环素组(45 mg/kg)、灯盏花素低剂量组(0.1 mg/kg)、灯盏花素中剂量组(0.5 mg/kg)、灯盏花素高剂量组(1 mg/kg),每组10只,假手术组及模型组注射等量容积0.9%氯化钠注射液,治疗2周后,测定大鼠侧脑损伤周围存活的皮质神经元数目、实时荧光定量PCR(q RT-PCR)和免疫组化检测Beclin1的表达水平,使用ELISA检测免疫因子白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)表达水平,采用蛋白免疫印迹(WB)检测TLR4和核因子-κB(NF-κB)表达情况。结果米诺环素组和灯盏花素组大鼠的皮质神经元存活率显著高于模型组(P<0.05),米诺环素组和灯盏花素组大鼠大脑皮层中Beclin1表达水平显著低于模型组(P<0.05),米诺环素组和灯盏花素组大鼠IL-6、TNF-α、TLR4和NF-κB表达水平显著低于模型组(P<0.05),呈现剂量依赖性。结论灯盏花素能够减弱脑外伤大鼠皮质神经元自噬和炎症损伤,这一作用可能通过抑制TLR4/NF-κB信号通路来实现。

Objective： To investigate the effects of breviscapine on autophagy and inflammatory damage in cor- tical neurons of rats with traumatic brain injury （TBI） and its molecular mechanism. Methods： The 10 rats were randomly selected as the sham operation group,and the other rats were treated with TBI,and the models were di- vided into 5 groups ： the model group, minocycline group （ iv.45 mg/kg）, low dose of breviscapine group （ iv.0.1 mg/ kg）,medium dose of breviseapine group （iv.0.5 mg/kg）,and high dose of breviseapine group （iv. 1 mg/kg）, 10 rats in each group. The sham operation group and the model group were given equal volume of saline. After 2 weeks of treatment, the number of surviving cortical neurons around the lateral brain injury in rats was measured. Real time fluorescence quantitative PCR （qRT-PCR） and immunohistochemistry were used to detect the expres- sion level of Beclinl. ELISA was used to detect the expression of IL-6and TNF-α. Western blot （WB） was used to detect the expression of TLR4 and NF-KB. Results： In minocycline group and breviscapine groups,the sur- vival rate of cortical neurons in rats was significantly higher than that in the model group （P〈 0.05）;the expres- sion level of Beclin 1 in the rat cerebral cortex was significantly lower than that of the model group （P〈 0.05 ） ;the expression level of IL-6,TNF-α,TLR4 and NF-KB was significantly lower than that of the model group （P 〈 0.05 ） ,in a dose-dependent manner. Conclusion： Breviscapine can attenuate autophagy and inflammatmy damage in cortical neurons of rats with TBI,and this effect may be aehieved by inhibiting tile TLR4/NF-KB signaling pathways.