Reductions in bacterial viability stimulate the production of Extra-intestinal Pathogenic Escherichia coli (ExPEC) cytoplasm-carrying Extracellular Vesicles (EVs).
Reductions in bacterial viability stimulate the production of Extra-intestinal Pathogenic Escherichia coli (ExPEC) cytoplasm-carrying Extracellular Vesicles (EVs).
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细菌活力的降低刺激肠外致病性大肠杆菌 (ExPEC) 细胞质携带的细胞外囊泡 (EV) 的产生
DOI：
10.1371/journal.ppat.1010908
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发表时间：
2022-10
期刊：
影响因子：
6.7
通讯作者：
中科院分区：
文献类型：
--
作者：
肠外致病性大肠杆菌（ExPEC）被定义为一种肠外食源性病原体，几种优势序列型（STs）的ExPEC分离株具有高毒力，具有人畜共患的潜力。细菌细胞外囊泡（EVs）携带特定的分子货物亚群，影响细菌和宿主的各种生物过程。EVs在exic中的形成机制仍有待阐明。本研究采用超离心方法分离了不同STs的expc菌株纯化的ev。菌株蛋白质组学的比较分析表明，细胞质蛋白在expc ev中所占比例较高。用简单的绿色荧光蛋白（GFP）表达法计算expc ev中携带细胞质囊泡的比例。依赖于RecA/ lexa的SOS反应是产生携带细胞质的ev的关键介质。SOS反应激活了噬菌体相关内溶素Epel1、Epel2.1和Epel2.2的表达，引发细胞裂解，增加了携带expc细胞质的ev的产生。抑制因子LexA通过结合内溶素启动子区域的SOS盒子直接控制这些内溶素的表达。细菌活力的降低刺激了exic ev的产生，尤其是携带细胞质的ev。H2O2暴露导致的细胞分裂失衡、ftsK基因缺失或t6A合成缺陷激活了依赖RecA/ lexa的SOS反应，诱导了内溶素的表达，从而增加了携带细胞质的EVs在总expc EVs中的比例。抗生素虽然降低了细菌活力，但也通过SOS反应增加了携带exic细胞质的ev的产生。细胞质携带ev比例的变化影响了exic ev的总DNA含量。当巨噬细胞暴露于更高比例的携带细胞质的囊泡中时，exic ev对巨噬细胞具有更强的细胞毒性，并伴有更严重的线粒体破坏和更高水平的诱导内禀凋亡。综上所述，我们对exic ev的蛋白质组学分析提供了全面的见解。本研究揭示了携带大肠杆菌胞浆的ev的新形成机制。
Extra-intestinal Pathogenic Escherichia coli (ExPEC) is defined as an extra-intestinal foodborne pathogen, and several dominant sequence types (STs) ExPEC isolates are highly virulent, with zoonotic potential. Bacteria extracellular vesicles (EVs) carry specific subsets of molecular cargo, which affect various biological processes in bacteria and host. The mechanisms of EVs formation in ExPEC remains to be elucidated. Here, the purified EVs of ExPEC strains of different STs were isolated with ultracentrifugation processes. A comparative analysis of the strain proteomes showed that cytoplasmic proteins accounted for a relatively high proportion of the proteins among ExPEC EVs. The proportion of cytoplasm-carrying vesicles in ExPEC EVs was calculated with a simple green fluorescent protein (GFP) expression method. The RecA/LexA-dependent SOS response is a critical mediator of generation of cytoplasm-carrying EVs. The SOS response activates the expression of prophage-associated endolysins, Epel1, Epel2.1, and Epel2.2, which triggered cell lysis, increasing the production of ExPEC cytoplasm-carrying EVs. The repressor LexA controlled directly the expression of these endolysins by binding to the SOS boxes in the endolysin promoter regions. Reducing bacterial viability stimulated the production of ExPEC EVs, especially cytoplasm-carrying EVs. The imbalance in cell division caused by exposure to H2O2, the deletion of ftsK genes, or t6A synthesis defects activated the RecA/LexA-dependent SOS response, inducing the expression of endolysins, and thus increasing the proportion of cytoplasm-carrying EVs in the total ExPEC EVs. Antibiotics, which decreased bacterial viability, also increase the production of ExPEC cytoplasm-carrying EVs through the SOS response. Changes in the proportion of cytoplasm-carrying EVs affected the total DNA content of ExPEC EVs. When macrophages are exposed to a higher proportion of cytoplasm-carrying vesicles, ExPEC EVs were more cytotoxic to macrophages, accompanied with more-severe mitochondrial disruption and a higher level of induced intrinsic apoptosis. In summary, we offered comprehensive insight into the proteome analysis of ExPEC EVs. This study demonstrated the novel formation mechanisms of E. coli cytoplasm-carrying EVs.
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影响因子：
6.7
作者：
Bielaszewska M;Rüter C;Bauwens A;Greune L;Jarosch KA;Steil D;Zhang W;He X;Lloubes R;Fruth A;Kim KS;Schmidt MA;Dobrindt U;Mellmann A;Karch H
通讯作者：
Karch H
影响因子：
5.2
作者：
Aktar S;Okamoto Y;Ueno S;Tahara YO;Imaizumi M;Shintani M;Miyata M;Futamata H;Nojiri H;Tashiro Y
通讯作者：
Tashiro Y
DOI：
10.1073/pnas.1403683111
发表时间：
2014-04-15
影响因子：
11.1
作者：
Altindis, Emrah;Fu, Yang;Mekalanos, John J.
通讯作者：
Mekalanos, John J.
影响因子：
14.9
作者：
Franceschini A;Szklarczyk D;Frankild S;Kuhn M;Simonovic M;Roth A;Lin J;Minguez P;Bork P;von Mering C;Jensen LJ
通讯作者：
Jensen LJ
影响因子：
3.7
作者：
Blank K;Hensel M;Gerlach RG
通讯作者：
Gerlach RG