Antimicrobial Peptide CMA3 Derived from the CA-MA Hybrid Peptide: Antibacterial and Anti-inflammatory Activities with Low Cytotoxicity and Mechanism of Action in Escherichia coli
Antimicrobial Peptide CMA3 Derived from the CA-MA Hybrid Peptide: Antibacterial and Anti-inflammatory Activities with Low Cytotoxicity and Mechanism of Action in Escherichia coli
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DOI：
10.1128/aac.01998-15
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发表时间：
2016-01-01
影响因子：
4.9
通讯作者：
Park, Yoonkyung
中科院分区：
文献类型：
--
作者：
Lee, Jong-kook;Seo, Chang Ho;Park, Yoonkyung
CA-MA是一种杂合抗菌肽（AMP），来源于两种天然存在的AMP，天蚕素A和爪蟾抗菌肽2。CA-MA对革兰氏阴性和革兰氏阳性细菌显示出强的抗微生物活性，但对哺乳动物细胞也显示出细胞毒性。我们的目标是通过用带正电荷的R基团（His和Lys）、脂肪族R基团（Leu）或极性R基团（Glu）系统地替换氨基酸来鉴定具有降低的细胞毒性的CA-MA类似物。在研究的CA-MA类似物（CMA 1至-6）中，CMA 3显示出最强的抗菌活性，包括对从医院患者中分离的耐药大肠杆菌和铜绿假单胞菌菌株的抗菌活性。CMA 3似乎通过诱导细菌膜中的孔形成（环形模型）起作用。在细胞毒性测定中，CMA 3对人红细胞（hRBC）或HaCaT细胞显示出很小的细胞毒性。此外，没有荧光从暴露于60 μ M CMA 3 80 s的小或巨大单层囊泡中释放，而荧光在暴露于CA-MA后35 s内释放。CMA 3在RAW 264.7细胞中也表现出很强的脂多糖（LPS）中和活性，并且在大肠杆菌感染后暴露于LPS的BALB/c小鼠在给予0.5 mg/kg体重或1 mg/kg剂量的CMA 3后显示出存活率提高。最后，在感染性休克小鼠模型中，CMA 3降低了促炎症因子（包括一氧化氮和白色血细胞）的水平，并相应减少了肺组织损伤。这项研究表明，CMA 3是一种抗菌/抗内毒素肽，可以作为开发具有低细胞毒性的抗炎和/或抗菌剂的基础。
CA-MA is a hybrid antimicrobial peptide (AMP) derived from two naturally occurring AMPs, cecropin A and magainin 2. CA-MA shows strong antimicrobial activity against Gram-negative and Gram-positive bacteria but also exhibits cytotoxicity toward mammalian cells. Our objective was to identify CA-MA analogues with reduced cytotoxicity by systematic replacement of amino acids with positively charged R groups (His and Lys), aliphatic R groups (Leu), or polar R groups (Glu). Among the CA-MA analogues studied (CMA1 to -6), CMA3 showed the strongest antimicrobial activity, including against drug-resistant Escherichia coli and Pseudomonas aeruginosa strains isolated from hospital patients. CMA3 appeared to act by inducing pore formation (toroidal model) in the bacterial membrane. In cytotoxicity assays, CMA3 showed little cytotoxicity toward human red blood cells (hRBCs) or HaCaT cells. Additionally, no fluorescence was released from small or giant unilamellar vesicles exposed to 60 mu M CMA3 for 80 s, whereas fluorescence was released within 35 s upon exposure to CA-MA. CMA3 also exerted strong lipopolysaccharide (LPS)-neutralizing activity in RAW 264.7 cells, and BALB/c mice exposed to LPS after infection by Escherichia coli showed improved survival after administration of one 0.5-mg/kg of body weight or 1-mg/kg dose of CMA3. Finally, in a mouse model of septic shock, CMA3 reduced the levels of proinflammatory factors, including both nitric oxide and white blood cells, and correspondingly reduced lung tissue damage. This study suggests that CMA3 is an antimicrobial/antiendotoxin peptide that could serve as the basis for the development of anti-inflammatory and/or antimicrobial agents with low cytotoxicity.