Claudin-3-deficient C57BL/6J mice display intact brain barriers
Claudin-3-deficient C57BL/6J mice display intact brain barriers
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DOI：
10.1038/s41598-018-36731-3
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发表时间：
2019-01-18
影响因子：
4.6
通讯作者：
Engelhardt, Britta
中科院分区：
文献类型：
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作者：
Dias, Mariana Castro;Coisne, Caroline;Engelhardt, Britta
紧密连接蛋白claudin-3已被确定为调节血脑屏障（BBB）成熟的Wnt/ β -连环蛋白信号通路的转录靶点。在神经系统疾病中，在血脑屏障和血脑脊液屏障（BCSFB）受损处观察到claudin-3免疫染色的丧失。尽管这些观察结果支持了claudin-3在调节脑屏障紧密连接完整性中的核心作用，但claudin-3在脑屏障中的表达仍然存在争议。这促使我们建立了claudin-3(-/-) C57BL/6J小鼠来研究claudin-3在健康和神经炎症的脑屏障完整性中的作用。对WT和claudin-3（-/-）小鼠的脑微血管样本进行大细胞和单细胞RNA测序和直接比较qRT-PCR分析，毫无疑问地表明，脑内皮细胞不表达claudin-3 mRNA。在体内和体外血脑屏障处检测到claudin-3蛋白是由于抗claudin-3抗体对一种未知抗原的连接反应性，这种抗原仍在claudin-3（-/-）脑内皮中检测到。我们证实了claudin-3在脉络膜丛BCSFB的表达和连接定位。我们的研究阐明了claudin-3不在血脑屏障处表达，表明在C57BL/6J小鼠健康和神经炎症期间，claudin-3的缺失不会损害脑屏障功能。
The tight junction protein claudin-3 has been identified as a transcriptional target of the Wnt/beta-catenin signaling pathway regulating blood-brain barrier (BBB) maturation. In neurological disorders loss of claudin-3 immunostaining is observed at the compromised BBB and blood-cerebrospinal fluid barrier (BCSFB). Although these observations support a central role of claudin-3 in regulating brain barriers' tight junction integrity, expression of claudin-3 at the brain barriers has remained a matter of debate. This prompted us to establish claudin-3(-/-) C57BL/6J mice to study the role of claudin-3 in brain barrier integrity in health and neuroinflammation. Bulk and single cell RNA sequencing and direct comparative qRT-PCR analysis of brain microvascular samples from WT and claudin-3(-/-) mice show beyond doubt that brain endothelial cells do not express claudin-3 mRNA. Detection of claudin-3 protein at the BBB in vivo and in vitro is rather due to junctional reactivity of anti-claudin-3 antibodies to an unknown antigen still detected in claudin-3(-/-) brain endothelium. We confirm expression and junctional localization of claudin-3 at the BCSFB of the choroid plexus. Our study clarifies that claudin-3 is not expressed at the BBB and shows that absence of claudin-3 does not impair brain barrier function during health and neuroinflammation in C57BL/6J mice.