A compensatory RNase E variation increases Iron Piracy and Virulence in multidrug-resistant Pseudomonas aeruginosa during Macrophage infection.
A compensatory RNase E variation increases Iron Piracy and Virulence in multidrug-resistant Pseudomonas aeruginosa during Macrophage infection.
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DOI：
10.1371/journal.ppat.1010942
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发表时间：
2023-04
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影响因子：
6.7
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中科院分区：
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在慢性囊性纤维化 (CF) 感染期间，铜绿假单胞菌抗生素耐药性的发展与肺部病情加重、肺功能下降和住院治疗有关。然而，人们对抗生素耐药性感染引起的更糟糕结果的毒力机制知之甚少。在这里，我们研究了进化的氨曲南耐药铜绿假单胞菌毒力机制。使用巨噬细胞感染模型并结合基因组和转录组分析，我们发现编码 RNase E 的 rne 基因的补偿性突变增加了pyoverdine 和 pyochelin 铁载体基因的表达，导致巨噬细胞铁死亡和裂解。我们发现，铁结合的绿脓杆菌足以引起巨噬细胞铁死亡和裂解，然而，脱辅基绿脓杆菌、铁结合的脓毒素或脱辅基脓毒素不足以杀死巨噬细胞。通过用铁模拟镓处理可以消除巨噬细胞的杀伤作用。临床分离株中存在丰富的 RNase E 变体，CF 痰基因表达数据显示临床分离株在巨噬细胞感染期间具有表型化的 RNase E 变体功能。这些数据共同表明，铜绿假单胞菌 RNase E 变体如何通过增加铁载体产生和宿主细胞铁死亡来造成宿主损伤，但也可能成为镓精准治疗的目标。在囊性纤维化 (CF) 患者中，铜绿假单胞菌在长达数十年的肺部感染过程中会对抗生素产生耐药性，而耐药性与 CF 患者的更糟糕的结果有关。虽然耐药性明显降低了治疗效果，但人们对耐药菌用于导致更严重疾病的毒力功能知之甚少。在这里，我们研究了抗生素耐药性铜绿假单胞菌的毒力机制。我们发现，耐药细菌能够更有效地杀死巨噬细胞免疫细胞，而这一过程是由编码 RNase E 的细菌基因突变驱动的，RNase E 是细菌中用于降解信使 RNA 的关键酶。我们证明，RNase E 突变导致铜绿假单胞菌过量产生铁清除铁载体分子，进而损害巨噬细胞细胞膜。在感染 CF 的铜绿假单胞菌中也检测到了 RNase E 变体，这表明这些变体可以帮助这种细菌在人类感染期间对抗免疫细胞。我们还表明，镓是一种新兴的抗菌药物，可以降低 RNase E 变体的毒力，这表明镓可以用作这些危险感染的精准治疗方法。这些发现揭示了 RNase E 变体和铁载体在细菌发病机制中的新作用。
During chronic cystic fibrosis (CF) infections, evolved Pseudomonas aeruginosa antibiotic resistance is linked to increased pulmonary exacerbations, decreased lung function, and hospitalizations. However, the virulence mechanisms underlying worse outcomes caused by antibiotic resistant infections are poorly understood. Here, we investigated evolved aztreonam resistant P. aeruginosa virulence mechanisms. Using a macrophage infection model combined with genomic and transcriptomic analyses, we show that a compensatory mutation in the rne gene, encoding RNase E, increased pyoverdine and pyochelin siderophore gene expression, causing macrophage ferroptosis and lysis. We show that iron-bound pyochelin was sufficient to cause macrophage ferroptosis and lysis, however, apo-pyochelin, iron-bound pyoverdine, or apo-pyoverdine were insufficient to kill macrophages. Macrophage killing could be eliminated by treatment with the iron mimetic gallium. RNase E variants were abundant in clinical isolates, and CF sputum gene expression data show that clinical isolates phenocopied RNase E variant functions during macrophage infection. Together these data show how P. aeruginosa RNase E variants can cause host damage via increased siderophore production and host cell ferroptosis but may also be targets for gallium precision therapy. In people with cystic fibrosis (CF), Pseudomonas aeruginosa becomes antibiotic resistant during decades-long lung infections and resistance is linked to worse outcomes in people with CF. While resistance clearly reduces treatment efficacy, the virulence functions used by resistant bacteria to drive worse disease are poorly understood. Here we investigated virulence mechanisms in antibiotic resistant P. aeruginosa. We show that resistant bacteria are more effective at killing macrophage immune cells, and this process is driven by a mutation in a bacterial gene encoding RNase E, a key enzyme in bacteria used to degrade messenger RNAs. We demonstrate that the RNase E mutation causes P. aeruginosa to overproduce iron scavenging siderophore molecules that, in turn, damage macrophage cell membranes. RNase E variants are also detected in P. aeruginosa infecting people with CF, suggesting that these variants could help this bacterium fight immune cells during human infections. We also show that gallium, an emerging antibacterial, can reduce virulence of RNase E variants, which indicates that gallium could be used as a precision treatment for these dangerous infections. These findings reveal new roles for RNase E variants and siderophores in bacterial pathogenesis.
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影响因子：
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作者：
BRITIGAN, BE;RASMUSSEN, GT;COX, CD
通讯作者：
COX, CD
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Argüelles S
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3.1
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ANKENBAUER, R;SRIYOSACHATI, S;COX, CD
通讯作者：
COX, CD
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3.1
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Cox, CD
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12.4
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Simon, H. U.