Treponema pallidum Tp0751 alters the expression of tight junction proteins by promoting bEnd3 cell apoptosis and IL-6 secretion
Treponema pallidum Tp0751 alters the expression of tight junction proteins by promoting bEnd3 cell apoptosis and IL-6 secretion
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DOI：
10.1016/j.ijmm.2022.151553
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发表时间：
2022-03-28
影响因子：
4.1
通讯作者：
Wu, Yimou
中科院分区：
文献类型：
--
作者：
Lu, Simin;Wang, Jianye;Wu, Yimou
背景：神经梅毒是由梅毒螺旋体（Treponema pallidum subsp.）侵入中枢神经系统引起的严重并发症。苍白球（T.苍白球）。然而，T.目的：本实验设计的主要目的是探讨T。方法：采用BEnd 3细胞体外构建单层血脑屏障模型。经重组蛋白TP 0751刺激后，通过跨内皮细胞阻力仪和透射电镜观察血脑屏障模型的完整性。Hoechst 33258染色和流式细胞术检测细胞凋亡率。Western blotting检测细胞紧密连接蛋白和凋亡相关蛋白的表达。酶活性检测试剂盒负责检测Caspase 3、Caspase 8和Caspase 9的酶活性。结果：Tp 0751作用于bEnd 3细胞后，细胞间紧密连接结构未出现明显断裂，但紧密连接蛋白紧密连接蛋白zonula occludens-1和occludin的表达水平降低。此外，进一步的研究表明，在与bEnd 3细胞孵育后，Tp 0751通过caspase 8/caspase 3途径以浓度和时间依赖的方式诱导细胞凋亡。这些凋亡过程可能导致紧密连接蛋白表达的变化。此外，Tp 0751蛋白可能参与了T.结论：本研究首次揭示并强调了Tp 0751可能通过诱导细胞凋亡和促进炎性细胞因子IL-6的分泌，影响紧密连接蛋白的表达，从而在神经梅毒的发病过程中发挥作用。苍白球
Background: Neurosyphilis is a serious complication caused by the invasion of the central nervous system by Treponema pallidum subsp. pallidum (T. pallidum). However, the molecular mechanism by which T. pallidum crosses the blood-brain barrier has not been fully elucidated.Objectives: The primary purpose of this experimental design was to explore the effect of the T. pallidum adhesion protein Tp0751 on the blood-brain barrier and cerebrovascular endothelial cells.Methods: BEnd3 cells were used to construct a monolayer blood-brain barrier model in vitro. The integrity of blood-brain barrier model was evaluated by a transendothelial cell resistance meter and transmission electron microscope after the stimulation of recombinant protein TP0751. Hoechst 33258 staining and flow cytometry were used to detect the apoptosis rate. Western blotting assay was used to measure the expression of tight junction proteins and apoptosis-related proteins. The enzyme activity detection kit was responsible for detecting the enzyme activities of Caspase 3, Caspase 8 and Caspase 9. The expression of pro-inflammatory cytokines TNF-alpha, IL-1 beta and IL-6 at the transcription and translation levels were detected by qRT-PCR and ELISA, respectively.Results: The results showed that, the tight junction structures between cells showed no obvious fragmentation, but the levels of the tight junction proteins zonula occludens-1 and occludin were reduced by the effects of Tp0751 on bEnd3 cells. In addition, further research demonstrated that after incubation with bEnd3 cells, Tp0751 induced cell apoptosis in a concentration-and time-dependent manner via the caspase 8/caspase 3 pathway. These apoptotic processes may have contributed to the changes in tight junction proteins expression. Furthermore, the Tp0751 protein may be involved in the pathogenic process by which T. pallidum crosses the blood-brain barrier by promoting secretion of the proinflammatory factor interleukin-6.Conclusions: On the whole, this study is the first to reveal and highlight that Tp0751 may affect the expression of tight junction proteins by inducing apoptosis and promoting the secretion of the inflammatory cytokine IL-6, thus playing a role in the progression of neurosyphilis caused by T. pallidum.