Chen Mianmian, Zhang Jiaxue, Xia Jing, Sun Jing, Zhang Xian, Xu Jiali, Deng Simin, Han Yue, Jiang Lingli, Song Houhui, Cheng Changyong
Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China.
Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China.
Microbiol Spectr. 2023 Sep 5;11(5):e0236523. doi: 10.1128/spectrum.02365-23.
Glutathione (GSH) is an essential component of the glutaredoxin (Grx) system, and it is synthesized by the enzyme glutathione synthase GshF in . GSH plays a crucial role in regulating virulence by modifying the virulence factors LLO and PrfA. In this study, we investigated the involvement of GshF in oxidative tolerance and intracellular infection. Our findings revealed that the deletion of resulted in a significant reduction in bacterial growth when exposed to diamide and copper ions stress. More importantly, this deletion also impaired the efficiency of invasion and proliferation in macrophages and mice organs. Furthermore, GshF influenced global transcriptional profiles, including carbohydrate and amino acid metabolism, particularly those related to the phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) genes , under oxidative stress conditions. In the wild-type strain, the transcription of was notably downregulated in response to copper ions and diamide stress compared to normal conditions. However, in the absence of , the transcripts of were upregulated in response to these stress conditions. Notably, the deletion of () enhanced oxidative stress tolerance to copper ions, whereas overexpression of reduced this resistance. In conclusion, our study provides the first evidence that GshF plays a crucial role in bacterial antioxidation through the regulation of .IMPORTANCE has developed various mechanisms to withstand oxidative stress, including the thioredoxin and glutaredoxin systems. However, the specific role of the glutathione synthase GshF, responsible for synthesizing GSH in , in oxidative tolerance remains unclear. This study aimed to elucidate the relationship between GshF and oxidative tolerance in by examining the efficiency of invasion and proliferation in macrophages and mice organs, as well as analyzing global transcriptional profiles under oxidative stress conditions. The results revealed that GshF plays a significant role in ' response to oxidative stress. Notably, GshF acts to suppress the transcription of phosphoenolpyruvate-carbohydrate phosphotransferase system genes , among which () was identified as the most critical gene for resisting oxidative stress. These findings enhance our understanding of how adapts to its environment and provide valuable insights for investigating the environmental adaptation mechanisms of other pathogenic bacteria.
谷胱甘肽（GSH）是谷氧还蛋白（Grx）系统的重要组成部分，由谷胱甘肽合酶GshF在……中合成。GSH通过修饰毒力因子LLO和PrfA在调节毒力方面发挥关键作用。在本研究中，我们调查了GshF在氧化耐受和细胞内感染中的作用。我们的研究结果表明，缺失……会导致细菌在暴露于二酰胺和铜离子胁迫时生长显著减少。更重要的是，这种缺失还损害了在巨噬细胞和小鼠器官中的侵袭和增殖效率。此外，在氧化应激条件下，GshF影响全局转录谱，包括碳水化合物和氨基酸代谢，特别是那些与磷酸烯醇丙酮酸 - 碳水化合物磷酸转移酶系统（PTS）基因相关的代谢。在野生型菌株中，与正常条件相比，在铜离子和二酰胺胁迫下，……的转录明显下调。然而，在缺失……的情况下，在这些胁迫条件下，……的转录本上调。值得注意的是，缺失……（）增强了对铜离子的氧化应激耐受性，而……的过表达降低了这种抗性。总之，我们的研究提供了首个证据，表明GshF通过调节……在细菌抗氧化中起关键作用。重要性……已发展出多种机制来抵御氧化应激，包括硫氧还蛋白和谷氧还蛋白系统。然而，负责在……中合成GSH的谷胱甘肽合酶GshF在氧化耐受中的具体作用仍不清楚。本研究旨在通过检查在巨噬细胞和小鼠器官中的侵袭和增殖效率，以及分析氧化应激条件下的全局转录谱，阐明GshF与……氧化耐受之间的关系。结果表明，GshF在……对氧化应激的反应中起重要作用。值得注意的是，GshF起到抑制磷酸烯醇丙酮酸 - 碳水化合物磷酸转移酶系统基因……转录的作用，其中……（）被确定为抵抗氧化应激的最关键基因。这些发现增进了我们对……如何适应其环境的理解，并为研究其他病原菌的环境适应机制提供了有价值的见解。
