Shiga toxin type-2 (Stx2) induces glutamate release via phosphoinositide 3-kinase (PI3K) pathway in murine neurons.
Shiga toxin type-2 (Stx2) induces glutamate release via phosphoinositide 3-kinase (PI3K) pathway in murine neurons.
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DOI：
10.3389/fnmol.2015.00030
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发表时间：
2015
影响因子：
4.8
通讯作者：
Latinovic OS
中科院分区：
文献类型：
--
作者：
Obata F;Hippler LM;Saha P;Jandhyala DM;Latinovic OS
产滋贺毒素大肠杆菌（STEC）可引起中枢神经系统（CNS）损伤，导致瘫痪、癫痫发作和昏迷。与导致CNS损害的全身性疾病相关的关键STEC毒力因子是滋贺毒素（Stx）。虽然神经元在体内表达Stx受体神经酰胺三己糖苷（Gb 3），但尚未研究Stx对神经元的直接毒性。我们使用小鼠新生神经元培养物来研究滋贺毒素2型（Stx 2）与细胞表面表达的Gb 3的相互作用。单分子成像三维随机光学重建显微镜-全内反射荧光（3D STORM-TIRF）可以可视化和量化Stx 2-Gb 3相互作用。此外，我们证明，Stx 2增加神经元胞质Ca 2+，NMDA受体抑制阻断Stx 2诱导的Ca 2+内流，表明Stx 2介导的谷氨酸释放。Wortmannin对磷酸肌醇3-激酶（PI 3 K）的特异性抑制降低了Stx 2诱导的细胞内Ca 2+，表明PI 3 K信号通路可能参与Stx 2相关的谷氨酸释放，并且这些通路可能导致与STEC感染相关的CNS损伤。
Shiga toxin-producing Escherichia coli (STEC) can cause central nervous system (CNS) damage resulting in paralysis, seizures, and coma. The key STEC virulence factors associated with systemic illness resulting in CNS impairment are Shiga toxins (Stx). While neurons express the Stx receptor globotriaosylceramide (Gb3) in vivo, direct toxicity to neurons by Stx has not been studied. We used murine neonatal neuron cultures to study the interaction of Shiga toxin type 2 (Stx2) with cell surface expressed Gb3. Single molecule imaging three dimensional STochastic Optical Reconstruction Microscopy—Total Internal Reflection Fluorescence (3D STORM-TIRF) allowed visualization and quantification of Stx2-Gb3 interactions. Furthermore, we demonstrate that Stx2 increases neuronal cytosolic Ca2+, and NMDA-receptor inhibition blocks Stx2-induced Ca2+ influx, suggesting that Stx2-mediates glutamate release. Phosphoinositide 3-kinase (PI3K)-specific inhibition by Wortmannin reduces Stx2-induced intracellular Ca2+ indicating that the PI3K signaling pathway may be involved in Stx2-associated glutamate release, and that these pathways may contribute to CNS impairment associated with STEC infection.