Rapôso Catarina, Odorissi Paulo Alexandre Miranda, Savioli Stefania Fioravanti, Hell Rafaela Chitarra Rodrigues, Simões Gustavo Ferreira, Ruela-de-Sousa Roberta R, de Oliveira Alexandre Leite Rodrigues, da Cruz-Höfling Maria Alice
Department of Biochemistry and Tissue Biology, State University of Campinas- Unicamp, Campinas, São Paulo, Brazil.
Department of Functional and Structural Biology, State University of Campinas- Unicamp, Campinas, São Paulo, Brazil.
PLoS One. 2014 Sep 11;9(9):e107292. doi: 10.1371/journal.pone.0107292. eCollection 2014.
Severe accidents caused by the "armed" spider Phoneutria nigriventer cause neurotoxic manifestations in victims. In experiments with rats, P. nigriventer venom (PNV) temporarily disrupts the properties of the BBB by affecting both the transcellular and the paracellular route. However, it is unclear how cells and/or proteins participate in the transient opening of the BBB. The present study demonstrates that PNV is a substrate for the multidrug resistance protein-1 (MRP1) in cultured astrocyte and endothelial cells (HUVEC) and increases mrp1 and cx43 and down-regulates glut1 mRNA transcripts in cultured astrocytes. The inhibition of nNOS by 7-nitroindazole suggests that NO derived from nNOS mediates some of these effects by either accentuating or opposing the effects of PNV. In vivo, MRP1, GLUT1 and Cx43 protein expression is increased differentially in the hippocampus and cerebellum, indicating region-related modulation of effects. PNV contains a plethora of Ca(2+), K(+) and Na(+) channel-acting neurotoxins that interfere with glutamate handling. It is suggested that the findings of the present study are the result of a complex interaction of signaling pathways, one of which is the NO, which regulates BBB-associated proteins in response to PNV interference on ions physiology. The present study provides additional insight into PNV-induced BBB dysfunction and shows that a protective mechanism is activated against the venom. The data shows that PNV has qualities for potential use in drug permeability studies across the BBB.
“武装”蜘蛛黑腹捕鸟蛛引发的严重事故会使受害者出现神经毒性表现。在对大鼠的实验中，黑腹捕鸟蛛毒液（PNV）通过影响跨细胞途径和细胞旁途径，暂时破坏血脑屏障（BBB）的特性。然而，目前尚不清楚细胞和/或蛋白质如何参与血脑屏障的短暂开放。本研究表明，PNV是培养的星形胶质细胞和内皮细胞（人脐静脉内皮细胞，HUVEC）中多药耐药蛋白1（MRP1）的底物，并增加培养的星形胶质细胞中mrp1和cx43的表达，同时下调glut1 mRNA转录本。7-硝基吲唑对一氧化氮合酶（nNOS）的抑制作用表明，源自nNOS的一氧化氮（NO）通过增强或对抗PNV的作用来介导其中一些效应。在体内，MRP1、葡萄糖转运蛋白1（GLUT1）和连接蛋白43（Cx43）的蛋白表达在海马体和小脑中差异增加，表明存在区域相关的效应调节。PNV含有大量作用于钙（Ca2+）、钾（K+）和钠（Na+）通道的神经毒素，这些毒素会干扰谷氨酸的处理。本研究结果表明，这些发现是信号通路复杂相互作用的结果，其中一条信号通路是NO，它在PNV干扰离子生理的情况下调节与血脑屏障相关的蛋白质。本研究为PNV诱导的血脑屏障功能障碍提供了更多见解，并表明针对该毒液激活了一种保护机制。数据显示，PNV具有用于血脑屏障药物通透性研究的潜在价值。
