野黄芩素改善高糖诱导小胶质细胞活化引起的血脑屏障功能障碍

Scutellarein alleviates dysfunction of blood-brain-barrierinitiated by hyperglycemia-stimulated microglia cells

目的研究野黄芩素(scutellarein)对高糖诱导的小胶质细胞活化引起的血脑屏障功能障碍的改善。方法将神经小胶质细胞BV-2与小鼠脑血管内皮细胞bEnd.3共培养,建立血脑屏障细胞模型。跨内皮电阻实验和细胞渗漏实验检测内皮细胞屏障的损伤情况;酶联免疫吸附法测定BV2细胞上清中TNF-α的含量;免疫印迹法检测bEnd.3细胞中紧密连接蛋白,包括occludin、claudin1、claudin5和claudin19的表达。结果用高糖诱导活化BV-2细胞或用TNF-α直接刺激bEnd.3细胞都会损伤bEnd.3细胞构成的细胞屏障,野黄芩素可逆转这种损伤。野黄芩素可以减少高糖诱导活化的BV-2细胞中TNF-α的分泌。TNF-α可以降低bEnd.3细胞中紧密连接蛋白claudin1、claudin5和claudin19的表达,野黄芩素能够逆转TNF-α降低的claudin1和claudin19蛋白表达。结论野黄芩素可以阻断高糖诱导的神经小胶质细胞活化,减少炎性因子TNF-α的释放,缓解高糖诱导激活神经小胶质细胞和TNF-α直接刺激脑血管内皮细胞所导致的血脑屏障破损。

Aim To investigate the effect of scutellarein on the blood-brain barrier(BBB)dysfunction mediated by hyperglycemia-stimulated microglia cells.Methods The microglia cells(BV-2)were co-cultured with murine cerebrovascular endothelial cells(bEnd.3)to establish a blood-brain barrier cell model.The damage of endothelial barrier was measured by transendothelial electrical resistance and cell leakage assay.The amount of TNF-α in the supernatant from BV-2 cells was detected by enzyme-linked immunosorbent assay.The effect of scutellarein on the expression of tight junction proteins(including occluding,claudin1,claudin5 and claudin19)was detected by Western blot.Results HG-stimulated BV-2 co-cultured with bEnd.3 or TNF-α directly stimulated bEnd.3 damaged cellular barrier formed by bEnd.3 cells,which could be reversed by scutellarin.Scutellarein decreased the release of pro-inflammatory cytokine TNF-αfrom HG-stimulated microglia cells.TNF-α decreased the expression of tight junction proteins including claudin1,claudin5 and claudin19 in b.End3 cells,but scutellarein reversed such reduction induced by TNF-α.Conclusions Scutellarein decreases the release of pro-inflammatory cytokine TNF-α via abrogating hyperglycemia-stimulated microglia activation,and alleviates BBB dysfunction in brain endothelial cellsb.End3 induced by HG-stimulated microglial cells or TNF-α alone.