College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.
J Proteomics. 2021 Jan 6;230:103983. doi: 10.1016/j.jprot.2020.103983. Epub 2020 Sep 19.
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.
猪链球菌 2 型（SS2）是一种人畜共患病原体，可引起人类和猪的脑膜炎。然而，关于 SS2 感染后血脑屏障（BBB）的比较蛋白质表达的信息有限。丝氨酸/苏氨酸激酶（stk）基因的缺失可以降低 SS2 侵袭 BBB 的能力。在本研究中，我们使用 bEnd.3 细胞作为 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，以确定这两种菌株感染之间的差异。与 ZY05719 感染的细胞相比，Δstk 感染的细胞中有 241 种蛋白质高度上调，81 种蛋白质显著下调。获得的数据显示，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发生了重大变化。通过定量实时 PCR 筛选一些差异表达蛋白，以检查其在转录水平的调节，并用 Western blot 分析验证一些选定蛋白在翻译水平的变化。本研究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 STK 在 SS2 中的表达如何帮助细菌穿透 BBB 提供重要线索。意义：在 SS2 ZY05719 或 Δstk 菌株感染的 bEnd.3 细胞中进行了 SILAC 比较定量蛋白质组学分析。鉴定出 241 种上调和 81 种下调的差异表达蛋白（DEPs）。DEPs 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 Western blot 检测了一些 DEP，与定量蛋白质组学分析中相应蛋白的结果相似。
