Streptococcus suis serotype 2 (SS2) is a zoonotic pathogen causing meningitis in humans and pigs. However, information on the comparative protein expression of the blood-brain barrier (BBB) following SS2 infection is limited. Deletion of the serine/threonine kinase (stk) gene can decrease the ability of SS2 to invade the BBB. In the present study, bEnd.3 cells were used as the BBB model, and a SILAC comparative quantitative proteomic study of bEnd.3 cells infected with the SS2 ZY05719 or Δstk strain was performed to determine the differences between these strains infections. Compared with ZY05719-infected cells, 241 proteins were highly upregulated, and 81 were significantly downregulated in Δstk-infected cells. The obtained data revealed major changes in the proteins involved in RNA process, host cytoskeleton, tight junction disruption and immune response. Some differentially expressed proteins were screened by quantitative real-time PCR to examine their regulation at the transcriptional level, and western blot analysis was used to validate the changes of some selected proteins at the translational level. The results obtained in this study may be useful to understand the host response to SS2 infection and provide crucial clues to decipher how STK expression in SS2 helps the bacteria penetrate the BBB.

Significance

A SILAC comparative quantitative proteomic assay was performed in bEnd.3 cells infected with the SS2 ZY05719 or Δstk strain. 241 upregulated and 81 downregulated differentially expressed proteins (DEPs) were identified. DEPs are involved in RNA process, host cytoskeleton, tight junction disruption and immune response. Some DEPs were examined by qPCR and western blot assays, which were similar to those of their corresponding proteins in the quantitative proteomics analysis.

中文翻译：

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用猪链球菌血清型 2 的野生型和 stk 缺陷型菌株感染的 bEnd.3 细胞的蛋白质组学分析揭示了蛋白质和通路调控。

猪链球菌血清型 2 (SS2) 是一种人畜共患病病原体，可引起人和猪的脑膜炎。然而，关于 SS2 感染后血脑屏障 (BBB) 的比较蛋白质表达的信息是有限的。丝氨酸/苏氨酸激酶 ( stk ) 基因的缺失可降低 SS2 侵入 BBB 的能力。本研究以bEnd.3细胞为BBB模型，对SS2 ZY05719或Δstk菌株感染的bEnd.3细胞进行SILAC比较定量蛋白质组学研究，以确定这些菌株感染之间的差异。与 ZY05719 感染的细胞相比，Δ stk中 241 种蛋白质高度上调，81 种蛋白质显着下调-感染的细胞。获得的数据揭示了参与 RNA 过程、宿主细胞骨架、紧密连接破坏和免疫反应的蛋白质的重大变化。通过定量实时PCR筛选一些差异表达的蛋白质，以检查它们在转录水平上的调节，并使用蛋白质印迹分析来验证一些选定蛋白质在翻译水平上的变化。本研究中获得的结果可能有助于了解宿主对 SS2 感染的反应，并为破译 SS2 中的 STK 表达如何帮助细菌穿透 BBB 提供重要线索。

意义

在感染了 SS2 ZY05719 或 Δ stk菌株的 bEnd.3 细胞中进行了 SILAC 比较定量蛋白质组学分析。鉴定了 241 个上调和 81 个下调的差异表达蛋白 (DEP)。DEP 参与 RNA 过程、宿主细胞骨架、紧密连接破坏和免疫反应。通过 qPCR 和蛋白质印迹分析对一些 DEP 进行了检查，这与定量蛋白质组学分析中的相应蛋白质相似。