Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli.
Epigallocatechin Gallate-Mediated Cell Death Is Triggered by Accumulation of Reactive Oxygen Species Induced via the Cpx Two-Component System in Escherichia coli.
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表没食子儿茶素没食子酸酯介导的细胞死亡是由大肠杆菌中的 Cpx 双组分系统诱导的活性氧物质的积累引发的
DOI：
10.3389/fmicb.2018.00246
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发表时间：
2018
影响因子：
5.2
通讯作者：
Li P
中科院分区：
文献类型：
--
作者：
Nie T;Zhang C;Huang A;Li P
表没食子儿茶素没食子酸酯（EGCG）是茶多酚中最具生物活性的成分，具有许多健康益处，其高抗菌活性是众所周知的。然而，人们对所涉及的机制知之甚少。在这里，我们发现了活性氧（ROS），Cpx系统和EGCG介导的细胞死亡之间的关系。我们首先发现氨苄青霉素抗性的增加以及参与细胞壁合成的LD-转肽酶（LD-TclG）的转录水平的增加; ycbB转录上调，而另一种LD-TclG，ynhG，在大肠杆菌短时间暴露于亚抑制剂量的EGCG后似乎是恒定的。此外，属于Cpx调节子的下游基因cpxP的转录水平与EGCG的浓度呈正相关，并且当用高剂量的EGCG处理细胞时检测到显著上调。通过对一株cpxR缺失菌株（ΔcpxR）的分析，我们发现ΔcpxR的活性氧水平恒定，存活率显著提高，而野生型菌株的活性氧水平升高，存活率显著降低。此外，硫脲，这是一种抗氧化剂，降低活性氧水平和抗菌活性的表没食子儿茶素。综上所述，这些结果表明，表没食子儿茶素没食子酸酯通过激活Cpx系统诱导ROS形成并介导细胞死亡。
The high antimicrobial activity of epigallocatechin gallate (EGCG), the most bioactive component of tea polyphenol with a number of health benefits, is well-known. However, little is known about the mechanism involved. Here, we discovered the relationship between reactive oxygen species (ROS), the Cpx system, and EGCG-mediated cell death. We first found an increase in ampicillin resistance as well as the transcription level of a LD-transpeptidase (LD-TPase) involved in cell wall synthesis; ycbB transcription was upregulated whereas that of another LD-TPase, ynhG, appeared to be constant after a short exposure of Escherichia coli to sub-inhibitory doses of EGCG. Additionally, the transcription level of cpxP, a downstream gene belonging to the Cpx regulon, was positively correlated with the concentration of EGCG, and significant upregulation was detected when cells were treated with high doses of EGCG. Through analysis of a cpxR deletion strain (ΔcpxR), we identified a constant ROS level and a notable increase in the survival rate of ΔcpxR, while the ROS level increased and the survival rate decreased remarkably in the wild-type strain. Furthermore, thiourea, which is an antioxidant, reduced the ROS level and antimicrobial activity of EGCG. Taken together, these results suggest that EGCG induces ROS formation by activating the Cpx system and mediates cell death.
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影响因子：
64.5
作者：
Kohanski MA;Dwyer DJ;Wierzbowski J;Cottarel G;Collins JJ
通讯作者：
Collins JJ
影响因子：
6
作者：
Nakayama, Motokazu;Shimatani, Kanami;Miyamoto, Takahisa
通讯作者：
Miyamoto, Takahisa
影响因子：
3.2
作者：
Mahoney, Tara F.;Silhavy, Thomas J.
通讯作者：
Silhavy, Thomas J.
影响因子：
3.2
作者：
Raivio, TL;Silhavy, TJ
通讯作者：
Silhavy, TJ
影响因子：
10.5
作者：
DANESE, PN;SNYDER, WB;SILHAVY, TJ
通讯作者：
SILHAVY, TJ