Combined Systems Approaches Reveal a Multistage Mode of Action of a Marine Antimicrobial Peptide against Pathogenic Escherichia coli and Its Protective Effect against Bacterial Peritonitis and Endotoxemia.
Combined Systems Approaches Reveal a Multistage Mode of Action of a Marine Antimicrobial Peptide against Pathogenic Escherichia coli and Its Protective Effect against Bacterial Peritonitis and Endotoxemia.
复制标题
组合系统方法揭示了海洋抗菌肽针对致病性大肠杆菌的多阶段作用模式及其对细菌性腹膜炎和内毒素血症的保护作用。
DOI：
10.1128/aac.01056-16
复制
发表时间：
2017-01
影响因子：
4.9
通讯作者：
Wang J
中科院分区：
文献类型：
--
作者：
Wang X;Teng D;Mao R;Yang N;Hao Y;Wang J
海洋 arenicin-3 衍生物 N4 对革兰氏阴性菌表现出有效的抗菌活性，但其抗菌作用模式仍然难以捉摸。本研究首次通过细胞学和转录组学相结合的技术研究了N4对抗致病性大肠杆菌的作用机制。 N4 肽在 1 分钟内透化外膜，0.5 小时后破坏质膜，并在 5 分钟内定位于细胞质。凝胶延迟和圆二色性 (CD) 光谱分析表明，N4 特异性结合 DNA 并破坏 DNA 构象，从 B 型变为 C 型。 N4 在 15 分钟内抑制 21.1% 的 DNA 和 20.6% 的 RNA 合成。 N4 诱导的大肠杆菌表现出细胞凋亡样细胞死亡的几个特征，例如细胞周期停滞在复制 (R) 和分裂 (D) 阶段、活性氧产生、质膜电位去极化以及 0.5 小时内染色质浓缩。透射电镜显示细胞形态变形、质膜消失、内容物渗漏、鬼细胞形成，N4几乎100%杀死细菌。共有428至663个差异表达基因参与对N4的反应，主要与膜生物发生（53.9%至56.7%）和DNA结合（13.3%至14.9%）有关。受到脂多糖 (LPS) 致命攻击的 N4 保护小鼠血清中白细胞介素 6 (IL-6)、IL-1β 和肿瘤坏死因子 α (TNF-α) 水平降低，并保护肺部免受 LPS 诱导的损伤。这些数据有助于加深对海洋抗菌肽（AMP）对抗革兰氏阴性菌的机制的了解，并为在无限海洋资源领域开发和应用新型多靶点 AMP 作为治疗药物提供指导。
A marine arenicin-3 derivative, N4, displayed potent antibacterial activity against Gram-negative bacteria, but its antibacterial mode of action remains elusive. The mechanism of action of N4 against pathogenic Escherichia coli was first researched by combined cytological and transcriptomic techniques in this study. The N4 peptide permeabilized the outer membrane within 1 min, disrupted the plasma membrane after 0.5 h, and localized in the cytoplasm within 5 min. Gel retardation and circular dichroism (CD) spectrum analyses demonstrated that N4 bound specifically to DNA and disrupted the DNA conformation from the B type to the C type. N4 inhibited 21.1% of the DNA and 20.6% of the RNA synthesis within 15 min. Several hallmarks of apoptosis-like cell death were exhibited by N4-induced E. coli, such as cell cycle arrest in the replication (R) and division(D) phases, reactive oxygen species production, depolarization of the plasma membrane potential, and chromatin condensation within 0.5 h. Deformed cell morphology, disappearance of the plasma membrane, leakage of the contents, and ghost cell formation were demonstrated by transmission electron microscopy, and nearly 100% of the bacteria were killed by N4. A total of 428 to 663 differentially expressed genes are involved in the response to N4, which are associated mainly with membrane biogenesis (53.9% to 56.7%) and DNA binding (13.3% to 14.9%). N4-protected mice that were lethally challenged with lipopolysaccharide (LPS) exhibited reduced levels of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) in serum and protected the lungs from LPS-induced injury. These data facilitate an enhanced understanding of the mechanisms of marine antimicrobial peptides (AMPs) against Gram-negative bacteria and provide guidelines in developing and applying novel multitarget AMPs in the field of unlimited marine resources as therapeutics.