Objective: Brain microvascular endothelial cells are integral components of the blood-brain barrier and play a role in protecting the brain from invading microbes. CXC motif chemokine ligand 1 (CXCL1) induces the chemotaxis of neutrophils, and neutrophils are important in host defense in the brain. However, dysregulated neutrophil infiltration leads to brain diseases. Toll-like receptor 3 (TLR3) is a pattern recognition receptor that recognizes viral double-stranded RNA (dsRNA). The aim of this study was to investigate the effect of an TLR3 agonist on the expression of CXCL1 in brain vascular endothelial cells. Methods: hCMEC/D3 human cerebral microvascular endothelial cells were cultured and treated with polyinosinic-polycytidylic acid (poly IC), a potent synthetic dsRNA agonist for TLR3. The production of CXCL1 mRNA and protein was assessed by real-time RT-PCR and ELISA. The expression of CXCL1 was compared with that of CXCL8. The effect of pretreatment of cells with a NF-κB inhibitor (SN50), a p38 mitogen-activated protein kinase (MAPK) inhibitor (SB203580), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), an interferon (IFN) regulatory factor 3 inhibitor (MRT67307), and an anti-type I IFN-neutralizing antibody mixture was examined. Phosphorylation of p38 was examined using Western blotting. Results: Treating cultured hCMEC/D3 human cells with poly IC induced the expression of CXCL1 as well as another chemokine CXCL8. Pretreatment of cells with SN50, SB203580, and SP600125 decreased the induction of CXCL1 by poly IC. However, it was not affected by MRT67307 or by an anti-type I IFN-neutralizing antibody mixture. Pretreatment of cells with SN50 decreased the poly IC-induced phosphorylation of p38. Conclusions: Poly IC induces the expression of CXCL1 in hCMEC/D3 cells. NF-κB, p38 MAPK, and JNK are involved in this reaction. There is a cross-talk between NF-κB and p38, and NF-κB partially regulates phosphorylation of p38. CXCL1 produced by brain microvascular endothelial cells may contribute to the brain’s defense against viral infection and various neurological diseases associated with neutrophil accumulation.
Neuroimmunomodulation

中文翻译：

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聚肌苷酸-聚胞苷酸在培养的hCMEC / D3人脑微血管内皮细胞中诱导CXCL1表达。

目的：脑微血管内皮细胞是血脑屏障的组成部分，在保护脑部免受微生物侵袭中发挥作用。CXC基序趋化因子配体1（CXCL1）诱导中性粒细胞的趋化性，中性粒细胞在脑部宿主防御中很重要。但是，嗜中性粒细胞浸润失调会导致脑部疾病。Toll样受体3（TLR3）是一种模式识别受体，可识别病毒双链RNA（dsRNA）。这项研究的目的是研究TLR3激动剂对脑血管内皮细胞CXCL1表达的影响。方法：培养hCMEC / D3人脑微血管内皮细胞，并用多肌苷-聚胞苷酸（poly IC）（一种有效的TLR3合成dsRNA激动剂）处理。通过实时RT-PCR和ELISA评估CXCL1 mRNA和蛋白质的产生。比较CXCL1和CXCL8的表达。用NF-κB抑制剂（SN50），p38丝裂原激活的蛋白激酶（MAPK）抑制剂（SB203580），c-Jun N端激酶（JNK）抑制剂（SP600125），干扰素预处理细胞的效果检查了IFN）调节因子3抑制剂（MRT67307）和抗I型IFN中和抗体的混合物。使用蛋白质印迹检查p38的磷酸化。结果：用poly IC处理培养的hCMEC / D3人细胞可诱导CXCL1和另一种趋化因子CXCL8的表达。用SN50，SB203580和SP600125预处理细胞会降低poly IC对CXCL1的诱导。但是，它不受MRT67307或抗I型IFN中和抗体混合物的影响。用SN50预处理细胞可降低多聚IC诱导的p38磷酸化。结论：Poly IC诱导hCMEC / D3细胞中CXCL1的表达。NF-κB，p38 MAPK和JNK参与该反应。NF-κB与p38之间存在串扰，而NF-κB部分调节p38的磷酸化。脑微血管内皮细胞产生的CXCL1可能有助于大脑防御病毒感染以及与中性粒细胞积累有关的各种神经系统疾病。
神经免疫调节