基于HMGB1/TLR4/NF-κB通路探讨丹红注射液对高脂血症合并脑缺血损伤大鼠神经保护作用

Discussion on the neuroprotective effects of Danhong Injection in hyperlipidemia rats with cerebral ischemia injury based on the regulation of HMGB1/TLR4/NF-κB pathway

目的:观察丹红注射液对高脂血症合并脑缺血损伤大鼠的神经保护作用,并探讨其可能的作用机制。方法:SD大鼠高脂饲料喂养6周,建立高脂血症模型,将造模成功的高脂血症大鼠随机分假手术组,模型组,丹红注射液低、中、高(0.5、1.0、2.0mL/kg)剂量组,然后采用Zea Longa线栓法建立大鼠脑缺血再灌注模型。24h后进行神经功能评分,尼氏染色观察脑皮层神经元病理变化,RT-PCR法检测大鼠缺血侧脑皮层中高迁移率族蛋白1(HMGB1)、Toll样受体4(TLR4)、髓样分化因子88(MyD88)、核因子κB(NF-κB) p65 mRNA的表达,免疫组化法检测BDNF和NF-κB p65的蛋白表达,ELISA法检测肝组织匀浆中总胆固醇(TC)、甘油三酯(TG)含量。结果:与模型组比较,丹红注射液各剂量组能不同程度降低脑缺血大鼠的神经功能评分(P<0.05,P<0.01),使大鼠缺血侧脑皮层中HMGB1、TLR4、MyD88、NF-κB p65 mRNA表达水平降低(P<0.05,P<0.01),升高BDNF阳性细胞表达(除丹红注射液低剂量组外)(P<0.01),抑制NF-κB p65蛋白表达(P<0.05,P<0.01),降低肝组织匀浆中TC、TG含量(P<0.01)。结论:丹红注射液能减轻高脂血症合并脑缺血大鼠的脑组织损伤,降低肝组织匀浆中TC和TG含量,其机制可能与上调BDNF的表达及抑制HMGB1/TLR4/NF-κB信号通路激活有关。

Objective: To observe the neuroprotective effects of Danhong Injection in hyperlipidemia rats with cerebral ischemia injury and explore its possible mechanism. Methods: SD rats were fed with high-fat diet for 6 weeks to establish the hyperlipidemia model. The successful hyperlipidemia model rats were randomly divided into hyperlipidemia sham operation group, hyperlipidemia with cerebral ischemia model group, and Danhong Injection low, medium and high(0.5, 1.0, 2.0 mL/kg) dose group. Then the rat cerebral ischemia-reperfusion model was established by the Zea Longa suture method. After 24 h, the neurological function scores were evaluated;the pathological changes of brain cortex neurons were observed by Nissl staining;the mRNA expressions of HMGB1, TLR4, MyD88 and NF-κB in the cerebral cortex of ischemic rats were detected by reverse transcription-polymerase chain reaction(RT-PCR);the protein expressions of brain-derived neurotrophic factor(BDNF) and NF-κB p65 were detected by immunohistochemistry;the contents of total cholesterol(TC) and triglyceride(TG) in liver tissue homogenate were detected by enzyme linked immunosorbent assay(ELISA). Results: Compared with the model group, Danhong Injection different dose groups reduced the neurological function score of rats with cerebral ischemia in different degrees(P<0.05, P<0.01), decreased the mRNA expressions of HMGB1, TLR4, MyD88 and NF-κB p65 in the cerebral brain cortex of ischemic rats(P<0.05, P<0.01), increased the expression of BDNF positive cells(Danhong Injection Low dose group besides)(P<0.01), inhibited the protein expression of NF-κB p65(P<0.05, P<0.01), and reduced the contents of TC and TG in liver homogenate(P<0.01). Conclusion: Danhong Injection can alleviate the brain tissue damage of hyperlipidemia rats with cerebral ischemia and reduce the contents of TC and TG in liver homogenate. The mechanism may be related to up-regulating the expression of BDNF and inhibiting the activation of HMGB1/TLR4/NF-κB signaling pathway.