栀子苷减轻LPS诱导的血脑屏障功能障碍

Geniposide alleviates LPS-induced blood-brain barrier dysfunction

目的探索栀子苷(geniposide,Gen)对脂多糖(lipopolysaccharide,LPS)诱导的血脑屏障(blood–brain barrier,BBB)功能障碍的作用和生物学机制。方法腹腔注射LPS制作大鼠脑白质损伤(white matter injury,WMI)模型,腹腔注射Gen干预WMI;通过埃文斯蓝(Evans blue,EB)染色和IgG染色检测BBB渗透性,免疫荧光染色观察脑组织中闭锁小带蛋白1(zonula occludens protein 1,ZO-1)和咬合蛋白(occludin)表达,胶质原纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和离子钙结合适配分子1(ionized calcium-binding adapter molecule 1,Iba1)标记法评估脑内星形胶质细胞和小胶质细胞活化;Western blot法检测脑组织中TLR4/NF-κB信号活性。结果LPS刺激明显增加EB和IgG的渗漏,破坏ZO-1和occludin在细胞连接处连续分布,促进星形胶质细胞和小胶质细胞活化,增加TLR4/NF-κB信号活性;而Gen治疗显著改善LPS诱导的上述指标变化。结论Gen能减轻LPS诱导的BBB功能障碍,其这种作用可能与其降低脑内星形胶质细胞和小胶质细胞活化和TLR4/NF-κB信号活性以及改善紧密连接蛋白的分布方式有关。

Objective To explore the effect and biological mechanism of geniposide(Gen)on blood-brain barrier(BBB)dysfunction induced by lipopolysaccharide(LPS).Methods LPS was injected intraperitoneally to make a rat model of white matter injury,and Gen was injected intraperitoneally to intervene WMI.BBB permeability was detected by Evans Blue(EB)staining and immunoglobulin G(IgG)staining.The expression distribution of zonula occludens protein 1(ZO-1)and occludin in brain tissue was observed by immunofluorescence staining.The activation of astrocytes and microglia in brain tissue was observed by glial fibrillary acidic protein(GFAP)labeling and ionized calcium-binding adapter molecule 1(Iba1)labeling.TLR4/NF-κB signaling activity in brain tissue was detected by Western blot.Results LPS stimulation significantly increased the leakage of EB and IgG(P<0.001),disrupted the continuous distribution of ZO-1 and occludin in cell junction,promoted the activation of astrocytes and microglia,and increased TLR4/NF-κB signaling activity.Gen treatment significantly improved LPS-induced changes of the above indexes.Conclusion Gen attenuates LPS-induced BBB dysfunction,which may be related to the reduction of astrocyte and microglial activation,TLR4/NF-κB signaling activity and the improvement of tight junction protein distribution in brain.