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Liu Q, Wu Q, Xu T, Malakar PK, Zhu Y, Liu J, Zhao Y, Zhang Z. Thanatin: A Promising Antimicrobial Peptide Targeting the Achilles' Heel of Multidrug-Resistant Bacteria. Int J Mol Sci 2024; 25:9496. [PMID: 39273441 PMCID: PMC11395501 DOI: 10.3390/ijms25179496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2024] [Revised: 08/28/2024] [Accepted: 08/30/2024] [Indexed: 09/15/2024] Open
Abstract
Antimicrobial resistance poses an escalating threat to human health, necessitating the development of novel antimicrobial agents capable of addressing challenges posed by antibiotic-resistant bacteria. Thanatin, a 21-amino acid β-hairpin insect antimicrobial peptide featuring a single disulfide bond, exhibits broad-spectrum antibacterial activity, particularly effective against multidrug-resistant strains. The outer membrane biosynthesis system is recognized as a critical vulnerability in antibiotic-resistant bacteria, which thanatin targets to exert its antimicrobial effects. This peptide holds significant promise for diverse applications. This review begins with an examination of the structure-activity relationship and synthesis methods of thanatin. Subsequently, it explores thanatin's antimicrobial activity, detailing its various mechanisms of action. Finally, it discusses prospective clinical, environmental, food, and agricultural applications of thanatin, offering valuable insights for future research endeavors.
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Affiliation(s)
- Qianhui Liu
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Qian Wu
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Tianming Xu
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Pradeep K Malakar
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Yongheng Zhu
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Jing Liu
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
| | - Zhaohuan Zhang
- College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
- International Research Center for Food and Health, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China
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Lim J, Myung H, Lim D, Song M. Antimicrobial peptide thanatin fused endolysin PA90 (Tha-PA90) for the control of Acinetobacter baumannii infection in mouse model. J Biomed Sci 2024; 31:36. [PMID: 38622637 PMCID: PMC11020296 DOI: 10.1186/s12929-024-01027-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 04/08/2024] [Indexed: 04/17/2024] Open
Abstract
BACKGROUND This study addresses the urgent need for infection control agents driven by the rise of drug-resistant pathogens such as Acinetobacter baumannii. Our primary aim was to develop and assess a novel endolysin, Tha-PA90, designed to combat these challenges. METHODS Tha-PA90 incorporates an antimicrobial peptide (AMP) called thanatin at its N-terminus, enhancing bacterial outer membrane permeability and reducing host immune responses. PA90 was selected as the endolysin component. The antibacterial activity of the purified Tha-PA90 was evaluated using an in vitro colony-forming unit (CFU) reduction assay and a membrane permeability test. A549 cells were utilized to measure the penetration into the cytosol and the cytotoxicity of Tha-PA90. Finally, infection control was monitored in A. baumannii infected mice following the intraperitoneal administration of Tha-PA90. RESULTS Tha-PA90 demonstrated remarkable in vitro efficacy, completely eradicating A. baumannii strains, even drug-resistant variants, at a low concentration of 0.5 μM. Notably, it outperformed thanatin, achieving only a < 3-log reduction at 4 μM. Tha-PA90 exhibited 2-3 times higher membrane permeability than a PA90 and thanatin mixture or PA90 alone. Tha-PA90 was found within A549 cells' cytosol with no discernible cytotoxic effects. Furthermore, Tha-PA90 administration extended the lifespan of A. baumannii-infected mice, reducing bacterial loads in major organs by up to 3 logs. Additionally, it decreased proinflammatory cytokine levels (TNF-α and IL-6), reducing the risk of sepsis from rapid bacterial lysis. Our findings indicate that Tha-PA90 is a promising solution for combating drug-resistant A. baumannii. Its enhanced efficacy, low cytotoxicity, and reduction of proinflammatory responses render it a potential candidate for infection control. CONCLUSIONS This study underscores the significance of engineered endolysins in addressing the pressing challenge of drug-resistant pathogens and offers insights into improved infection management strategies.
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Affiliation(s)
- Jeonghyun Lim
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea
| | - Heejoon Myung
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea
- LyseNTech Co., Ltd., Seongnam-Si, 13486, Republic of Korea
| | - Daejin Lim
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Miryoung Song
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea.
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Abdullah SJ, Yan BTS, Palanivelu N, Dhanabal VB, Bifani JP, Bhattacharjya S. Outer-Membrane Permeabilization, LPS Transport Inhibition: Activity, Interactions, and Structures of Thanatin Derived Antimicrobial Peptides. Int J Mol Sci 2024; 25:2122. [PMID: 38396798 PMCID: PMC10888688 DOI: 10.3390/ijms25042122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 01/30/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Currently, viable antibiotics available to mitigate infections caused by drug-resistant Gram-negative bacteria are highly limited. Thanatin, a 21-residue-long insect-derived antimicrobial peptide (AMP), is a promising lead molecule for the potential development of novel antibiotics. Thanatin is extremely potent, particularly against the Enterobacter group of Gram-negative pathogens, e.g., E. coli and K. pneumoniae. As a mode of action, cationic thanatin efficiently permeabilizes the LPS-outer membrane and binds to the periplasmic protein LptAm to inhibit outer membrane biogenesis. Here, we have utilized N-terminal truncated 16- and 14-residue peptide fragments of thanatin and investigated structure, activity, and selectivity with correlating modes of action. A designed 16-residue peptide containing D-Lys (dk) named VF16 (V1PIIYCNRRT-dk-KCQRF16) demonstrated killing activity in Gram-negative bacteria. The VF16 peptide did not show any detectable toxicity to the HEK 293T cell line and kidney cell line Hep G2. As a mode of action, VF16 interacted with LPS, permeabilizing the outer membrane and binding to LptAm with high affinity. Atomic-resolution structures of VF16 in complex with LPS revealed cationic and aromatic surfaces involved in outer membrane interactions and permeabilization. Further, analyses of an inactive 14-residue native thanatin peptide (IM14: IIYCNRRTGKCQRM) delineated the requirement of the β-sheet structure in activity and target interactions. Taken together, this work would pave the way for the designing of short analogs of thanatin-based antimicrobials.
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Affiliation(s)
- Swaleeha Jaan Abdullah
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; (S.J.A.); (N.P.)
| | - Bernice Tan Siu Yan
- A*Star Infectious Diseases Labs, 8A Biomedical Grove, Immunos, Singapore 138648, Singapore
| | - Nithya Palanivelu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; (S.J.A.); (N.P.)
| | - Vidhya Bharathi Dhanabal
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; (S.J.A.); (N.P.)
| | - Juan Pablo Bifani
- A*Star Infectious Diseases Labs, 8A Biomedical Grove, Immunos, Singapore 138648, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; (S.J.A.); (N.P.)
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Abdullah SJ, Mu Y, Bhattacharjya S. Structures, Interactions and Activity of the N-Terminal Truncated Variants of Antimicrobial Peptide Thanatin. Antibiotics (Basel) 2024; 13:74. [PMID: 38247633 PMCID: PMC10812785 DOI: 10.3390/antibiotics13010074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/23/2024] Open
Abstract
Gram-negative bacteria are intrinsically more resistant to many frontline antibiotics, which is attributed to the permeability barrier of the outer membrane, drug efflux pumps and porins. Consequently, discovery of new small molecules antibiotics to kill drug-resistant Gram-negative bacteria presents a significant challenge. Thanatin, a 21-residue insect-derived antimicrobial peptide, is known for its potent activity against Enterobacter Gram-negative bacteria, including drug-resistant strains. Here, we investigated a 15-residue N-terminal truncated analog PM15 (P1IIYCNRRTGKCQRM15) of thanatin to determine modes of action and antibacterial activity. PM15 and the P1 to Y and A substituted variants PM15Y and PM15A delineated interactions and permeabilization of the LPS-outer membrane. In antibacterial assays, PM15 and the analogs showed growth inhibition of strains of Gram-negative bacteria that is largely dependent on the composition of the culture media. Atomic-resolution structures of PM15 and PM15Y in free solution and in complex with LPS micelle exhibited persistent β-hairpin structures similar to native thanatin. However, in complex with LPS, the structures of peptides are more compact, with extensive packing interactions among residues across the two anti-parallel strands of the β-hairpin. The docked complex of PM15/LPS revealed a parallel orientation of the peptide that may be sustained by potential ionic and van der Waals interactions with the lipid A moiety of LPS. Further, PM15 and PM15Y bind to LptAm, a monomeric functional variant of LptA, the periplasmic component of the seven-protein (A-G) complex involved in LPS transport. Taken together, the structures, target interactions and antibacterial effect of PM15 presented in the current study could be useful in designing thanatin-based peptide analogs.
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Affiliation(s)
| | | | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; (S.J.A.); (Y.M.)
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Ye J, Chen X. Current Promising Strategies against Antibiotic-Resistant Bacterial Infections. Antibiotics (Basel) 2022; 12:antibiotics12010067. [PMID: 36671268 PMCID: PMC9854991 DOI: 10.3390/antibiotics12010067] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022] Open
Abstract
Infections caused by antibiotic-resistant bacteria (ARB) are one of the major global health challenges of our time. In addition to developing new antibiotics to combat ARB, sensitizing ARB, or pursuing alternatives to existing antibiotics are promising options to counter antibiotic resistance. This review compiles the most promising anti-ARB strategies currently under development. These strategies include the following: (i) discovery of novel antibiotics by modification of existing antibiotics, screening of small-molecule libraries, or exploration of peculiar places; (ii) improvement in the efficacy of existing antibiotics through metabolic stimulation or by loading a novel, more efficient delivery systems; (iii) development of alternatives to conventional antibiotics such as bacteriophages and their encoded endolysins, anti-biofilm drugs, probiotics, nanomaterials, vaccines, and antibody therapies. Clinical or preclinical studies show that these treatments possess great potential against ARB. Some anti-ARB products are expected to become commercially available in the near future.
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TPGS-based and S-thanatin functionalized nanorods for overcoming drug resistance in Klebsiella pneumonia. Nat Commun 2022; 13:3731. [PMID: 35768446 PMCID: PMC9243133 DOI: 10.1038/s41467-022-31500-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 06/20/2022] [Indexed: 11/12/2022] Open
Abstract
Tigecycline is regarded as the last line of defense to combat multidrug-resistant Klebsiella pneumoniae. However, increasing utilization has led to rising drug resistance and treatment failure. Here, we design a D-alpha tocopheryl polyethylene glycol succinate-modified and S-thanatin peptide-functionalized nanorods based on calcium phosphate nanoparticles for tigecycline delivery and pneumonia therapy caused by tigecycline-resistant Klebsiella pneumoniae. After incubation with bacteria, the fabricated nanorods can enhance tigecycline accumulation in bacteria via the inhibitory effect on efflux pumps exerted by D-alpha tocopheryl polyethylene glycol succinate and the targeting capacity of S-thanatin to bacteria. The synergistic antibacterial capacity between S-thanatin and tigecycline further enhances the antibacterial activity of nanorods, thus overcoming the tigecycline resistance of Klebsiella pneumoniae. After intravenous injection, nanorods significantly reduces the counts of white blood cells and neutrophils, decreases bacterial colonies, and ameliorates neutrophil infiltration events, thereby largely increasing the survival rate of mice with pneumonia. These findings may provide a therapeutic strategy for infections caused by drug-resistant bacteria. Overproduction of efflux pumps represents an important mechanism of Klebsiella pneumonia resistance to tigecycline. Here, the authors design TPGS- and S-thanatin functionalized nanorods loaded with tigecycline to increase drug accumulation inside bacteria and overcome bacterial resistance.
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Atomic-Resolution Structures and Mode of Action of Clinically Relevant Antimicrobial Peptides. Int J Mol Sci 2022; 23:ijms23094558. [PMID: 35562950 PMCID: PMC9100274 DOI: 10.3390/ijms23094558] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/18/2022] [Accepted: 04/18/2022] [Indexed: 02/01/2023] Open
Abstract
Global rise of infections and deaths caused by drug-resistant bacterial pathogens are among the unmet medical needs. In an age of drying pipeline of novel antibiotics to treat bacterial infections, antimicrobial peptides (AMPs) are proven to be valid therapeutics modalities. Direct in vivo applications of many AMPs could be challenging; however, works are demonstrating encouraging results for some of them. In this review article, we discussed 3-D structures of potent AMPs e.g., polymyxin, thanatin, MSI, protegrin, OMPTA in complex with bacterial targets and their mode of actions. Studies on human peptide LL37 and de novo-designed peptides are also discussed. We have focused on AMPs which are effective against drug-resistant Gram-negative bacteria. Since treatment options for the infections caused by super bugs of Gram-negative bacteria are now extremely limited. We also summarize some of the pertinent challenges in the field of clinical trials of AMPs.
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Sinha S, Dhanabal VB, Sperandeo P, Polissi A, Bhattacharjya S. Linking dual mode of action of host defense antimicrobial peptide thanatin: Structures, lipopolysaccharide and LptA m binding of designed analogs. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183839. [PMID: 34915021 DOI: 10.1016/j.bbamem.2021.183839] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
At present, antibiotics options to cure infections caused by drug resistant Gram-negative pathogens are highly inadequate. LPS outer membrane, proteins involved in LPS transport and biosynthesis pathways are vital targets. Thanatin, an insect derived 21-residue long antimicrobial peptide may be exploited for the development of effective antibiotics against Gram-negative bacteria. As a mode of bacterial cell killing, thanatin disrupts LPS outer membrane and inhibits LPS transport by binding to the periplasmic protein LptAm. Here, we report structure-activity correlation of thanatin and analogs for the purpose of rational design. These analogs of thanatin are investigated, by NMR, ITC and fluorescence, to correlate structure, antibacterial activity and binding with LPS and LptAm, a truncated monomeric variant. Our results demonstrate that an analog thanatin M21F exhibits superior antibacterial activity. In LPS interaction analyses, thanatin M21F demonstrate high affinity binding to outer membrane LPS. The atomic resolution structure of thanatin M21F in LPS micelle reveals four stranded β-sheet structure in a dimeric topology whereby the sidechain of aromatic residues Y10, F21 sustained mutual packing at the interface. Strikingly, LptAm binding affinity of thanatin M21F has been significantly increased with an estimated Kd ~ 0.73 nM vs 13 nM for thanatin. Further, atomic resolution structures and interactions of Ala based thanatin analogs define plausible correlations with antibacterial activity and LPS, LptAm interactions. Taken together, the current work provides a frame-work for the designing of thanatin based potent antimicrobial peptides for the treatment of drug resistance Gram-negative bacteria.
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Affiliation(s)
- Sheetal Sinha
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore
| | - Vidhya Bharathi Dhanabal
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Paola Sperandeo
- Dept. of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Alessandra Polissi
- Dept. of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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Fujita K, Takata I, Yoshida I, Takashima H, Sugiyama H. TP0586532, a non-hydroxamate LpxC inhibitor, reduces LPS release and IL-6 production both in vitro and in vivo. J Antibiot (Tokyo) 2022; 75:136-145. [PMID: 34987187 PMCID: PMC8728711 DOI: 10.1038/s41429-021-00498-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/06/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022]
Abstract
UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC) is an essential enzyme in the biosynthesis of Lipid A, an active component of lipopolysaccharide (LPS), from UDP-3-O-acyl-N-acetylglicosamine. LPS is a major component of the cell surface of Gram-negative bacteria. LPS is known to be one of causative factors of sepsis and has been associated with high mortality in septic shock. TP0586532 is a novel non-hydroxamate LpxC enzyme inhibitor. In this study, we examined the inhibitory effect of TP0586532 on the LPS release from Klebsiella pneumoniae both in vitro and in vivo. Our results confirmed the inhibitory effect of TP0586532 on LPS release from the pathogenic bacterial species. On the other hand, meropenem and ciprofloxacin increase the level of LPS release. Furthermore, the effects of TP0586532 on LPS release and interleukin (IL)-6 production in the lung were determined using a murine model of pneumonia caused by K. pneumoniae. As observed in the in vitro study, TP0586532 showed the marked inhibitory effect on LPS release in the lungs, whereas meropenem- and ciprofloxacin-treated mice showed higher levels of LPS release and IL-6 production in the lungs as compared to those in the lungs of vehicle-treated mice. Moreover, TP0586532 used in combination with meropenem and ciprofloxacin attenuated the LPS release and IL-6 production induced by meropenem and ciprofloxacin in the lung. These results indicate that the inhibitory effect of TP0586532 on LPS release from pathogenic bacteria might be of benefit in patients with sepsis.
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Affiliation(s)
- Kiyoko Fujita
- Pharmacology Laboratotries, Taisho Pharmaceutical Co., Ltd, Saitama, Japan
| | - Iichiro Takata
- Pharmacology Laboratotries, Taisho Pharmaceutical Co., Ltd, Saitama, Japan
| | - Ippei Yoshida
- Pharmacology Laboratotries, Taisho Pharmaceutical Co., Ltd, Saitama, Japan
| | - Hajime Takashima
- Chemistry Laboratories, Taisho Pharmaceutical Co., Ltd, Saitama, Japan
| | - Hiroyuki Sugiyama
- Pharmacology Laboratotries, Taisho Pharmaceutical Co., Ltd, Saitama, Japan. .,Medical information, Taisho Pharmaceutical Co., Ltd, Tokyo, Japan.
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Dash R, Bhattacharjya S. Thanatin: An Emerging Host Defense Antimicrobial Peptide with Multiple Modes of Action. Int J Mol Sci 2021; 22:ijms22041522. [PMID: 33546369 PMCID: PMC7913509 DOI: 10.3390/ijms22041522] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial peptides (AMPs) possess great potential for combating drug-resistant bacteria. Thanatin is a pathogen-inducible single-disulfide-bond-containing β-hairpin AMP which was first isolated from the insect Podisus maculiventris. The 21-residue-long thanatin displays broad-spectrum activity against both Gram-negative and Gram-positive bacteria as well as against various species of fungi. Remarkably, thanatin was found to be highly potent in inhibiting the growth of bacteria and fungi at considerably low concentrations. Although thanatin was isolated around 25 years ago, only recently has there been a pronounced interest in understanding its mode of action and activity against drug-resistant bacteria. In this review, multiple modes of action of thanatin in killing bacteria and in vivo activity, therapeutic potential are discussed. This promising AMP requires further research for the development of novel molecules for the treatment of infections caused by drug resistant pathogens.
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Affiliation(s)
- Rachita Dash
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore;
- Department of Systems and Computational Biology, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore;
- Correspondence:
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Papafilippou L, Claxton A, Dark P, Kostarelos K, Hadjidemetriou M. Nanotools for Sepsis Diagnosis and Treatment. Adv Healthc Mater 2021; 10:e2001378. [PMID: 33236524 DOI: 10.1002/adhm.202001378] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/07/2020] [Indexed: 12/12/2022]
Abstract
Sepsis is one of the leading causes of death worldwide with high mortality rates and a pathological complexity hindering early and accurate diagnosis. Today, laboratory culture tests are the epitome of pathogen recognition in sepsis. However, their consistency remains an issue of controversy with false negative results often observed. Clinically used blood markers, C reactive protein (CRP) and procalcitonin (PCT) are indicators of an acute-phase response and thus lack specificity, offering limited diagnostic efficacy. In addition to poor diagnosis, inefficient drug delivery and the increasing prevalence of antibiotic-resistant microorganisms constitute significant barriers in antibiotic stewardship and impede effective therapy. These challenges have prompted the exploration for alternative strategies that pursue accurate diagnosis and effective treatment. Nanomaterials are examined for both diagnostic and therapeutic purposes in sepsis. The nanoparticle (NP)-enabled capture of sepsis causative agents and/or sepsis biomarkers in biofluids can revolutionize sepsis diagnosis. From the therapeutic point of view, currently existing nanoscale drug delivery systems have proven to be excellent allies in targeted therapy, while many other nanotherapeutic applications are envisioned. Herein, the most relevant applications of nanomedicine for the diagnosis, prognosis, and treatment of sepsis is reviewed, providing a critical assessment of their potentiality for clinical translation.
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Affiliation(s)
- Lana Papafilippou
- Nanomedicine Lab Faculty of Biology Medicine and Health AV Hill Building The University of Manchester Manchester M13 9PT UK
| | - Andrew Claxton
- Department of Critical Care Salford Royal Foundation Trust Stott Lane Salford M6 8HD UK
| | - Paul Dark
- Manchester NIHR Biomedical Research Centre Division of Infection Immunity and Respiratory Medicine University of Manchester Manchester M13 9PT UK
| | - Kostas Kostarelos
- Nanomedicine Lab Faculty of Biology Medicine and Health AV Hill Building The University of Manchester Manchester M13 9PT UK
- Catalan Institute of Nanoscience and Nanotechnology (ICN2) Campus UAB Bellaterra Barcelona 08193 Spain
| | - Marilena Hadjidemetriou
- Nanomedicine Lab Faculty of Biology Medicine and Health AV Hill Building The University of Manchester Manchester M13 9PT UK
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Zhang R, Fan X, Jiang X, Zou M, Xiao H, Wu G. Multiple Mechanisms of the Synthesized Antimicrobial Peptide TS against Gram-Negative Bacteria for High Efficacy Antibacterial Action In Vivo. Molecules 2020; 26:molecules26010060. [PMID: 33374458 PMCID: PMC7795306 DOI: 10.3390/molecules26010060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 12/02/2022] Open
Abstract
The emergence of drug-resistant bacteria emphasizes the urgent need for novel antibiotics. The antimicrobial peptide TS shows extensive antibacterial activity in vitro and in vivo, especially in gram-negative bacteria; however, its antibacterial mechanism is unclear. Here, we find that TS without hemolytic activity disrupts the integrity of the outer bacterial cell membrane by displacing divalent cations and competitively binding lipopolysaccharides. In addition, the antimicrobial peptide TS can inhibit and kill E. coli by disintegrating the bacteria from within by interacting with bacterial DNA. Thus, antimicrobial peptide TS’s multiple antibacterial mechanisms may not easily induce bacterial resistance, suggesting use as an antibacterial drug to be for combating bacterial infections in the future.
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Affiliation(s)
- Rui Zhang
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Xiaobo Fan
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Xinglu Jiang
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Mingyuan Zou
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Han Xiao
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
| | - Guoqiu Wu
- Medical School, Southeast University, Nanjing 210009, China; (R.Z.); (X.F.); (X.J.); (M.Z.); (H.X.)
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Southeast University, Nanjing 210009, China
- Department of Clinical Laboratory Medicine, Zhongda Hospital, Southeast University, Nanjing 210009, China
- Correspondence: ; Tel.: +86-25-83272503
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Sinha S, Ng WJ, Bhattacharjya S. NMR structure and localization of the host defense antimicrobial peptide thanatin in zwitterionic dodecylphosphocholine micelle: Implications in antimicrobial activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183432. [PMID: 32781154 DOI: 10.1016/j.bbamem.2020.183432] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/11/2020] [Accepted: 07/24/2020] [Indexed: 02/07/2023]
Abstract
Antimicrobial peptides (AMPs) are potentially vital as the next generation of antibiotics against multidrug resistant bacterial pathogens. Thanatin, an insect derived pathogen inducible 21-residue long antimicrobial peptide, demonstrates antimicrobial activity toward broad range of pathogens. Thanatin is an excellent candidate for antibiotics development due to potent in vivo activity in animal model and low toxicity to human cells. Recent studies indicated mode of action of thanatin could be intriguing and may comprise bacterial membrane permeabilization and interactions with periplasmic proteins. In order to better understand selectivity and membrane disruption, here, we determined 3-D structure of the thanatin in zwitterionic DPC-d38 micelle by NMR spectroscopy. The depth of insertion of thanatin into micelle structure was investigated by spin labelled doxyl lipids, 5-DSA and 16-DSA. DPC-bound structure of thanatin is defined by a β-hairpin structure and an extended and turn conformations, for residues G1-I8, at the N-terminus. The β-hairpin structure is delineated by two antiparallel β-strands, residues I9-C11 and residues K17-R20, which is connected by loop consisted of residues N12-G16. There are cross β-strands sidechain-sidechain packing interactions among hydrophobic and aromatic residues. Spin labelled lipid studies revealed a set of spatially proximal residues V6, I8, Q19, R20 and M21 may be deeply inserted into the hydrophobic core of the DPC micelle. While, residues including those at the turn/loop are merely surface localized. The atomic resolution structure and orientation of thanatin in zwitterionic DPC micelle may be utilized for understating mode of action in lipid membrane and further development of non-toxic analogs.
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Affiliation(s)
- Sheetal Sinha
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore; Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore
| | - Wun Jern Ng
- Environmental Bio-Innovation Group (EBiG), School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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14
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Tanhaeian A, Azghandi M, Mousavi Z, Javadmanesh A. Expression of Thanatin in HEK293 Cells and Investigation of its Antibacterial Effects on Some Human Pathogens. Protein Pept Lett 2020; 27:41-47. [PMID: 31438823 PMCID: PMC6978649 DOI: 10.2174/0929866526666190822162140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Thanatin is the smallest member of Beta-hairpin class of cationic peptide derived from insects with vast activities against various pathogens. OBJECTIVE In this study, the antimicrobial activity of this peptide against some species of human bacterial pathogens as well as its toxicity on NIH cells were evaluated. METHODS Thanatin DNA sequence was cloned into pcDNA3.1+ vector and transformed into a DH5α bacterial strain. Then the recombinant plasmids were transfected into HEK-293 cells by calcium phosphate co-precipitation. After applying antibiotic treatment, the supernatant medium containing thanatin was collected. The peptide quantity was estimated by SDS-PAGE and GelQuant software. The antimicrobial activity of this peptide was performed with Minimum Inhibitory Concentration (MIC) method. In addition, its toxicity on NIH cells were evaluated by MTT assay. RESULTS The peptide quantity was estimated approximately 164.21 µmolL-1. The antibacterial activity of thanatin was estimated between 0.99 and 31.58 µmolL-1 using MIC method. The result of cytotoxicity test on NIH cell line showed that the peptide toxicity up to the concentration of 394.10 µmolL-1 and for 48 hours, was not statistically significant from negative control cells (P>0.05). The antimicrobial assay demonstrated that thanatin had an antibacterial effect on some tested microorganisms. The results obtained in this study also showed that thanatin had no toxicity on mammalian cell lines including HEK293 and NIH. CONCLUSION Antimicrobial peptides such as thanatin are considered to be appropriate alternatives to conventional antibiotics in treating various human pathological diseases bacteria.
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Affiliation(s)
- Abbas Tanhaeian
- Department of Plant Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Marjan Azghandi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Zahra Mousavi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ali Javadmanesh
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
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15
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Gao H, Bai Y, Chen L, Fakhri GE, Wang M. Self-Assembly Nanoparticles for Overcoming Multidrug Resistance and Imaging-Guided Chemo-Photothermal Synergistic Cancer Therapy. Int J Nanomedicine 2020; 15:809-819. [PMID: 32103938 PMCID: PMC7008176 DOI: 10.2147/ijn.s232449] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/02/2020] [Indexed: 12/29/2022] Open
Abstract
Background and Purpose The development of multiple drug resistance (MDR) to chemotherapy and single modal therapy remains unsatisfied for the eradication of tumor, which are major obstacles in cancer therapy. This novel system with excellent characteristics for inhibition of P-glycoprotein (P-gp), and for near-infrared fluorescence (NIRF) imaging-guided chemo-photothermal therapy (PTT), has been identified as a promising way to MDR and achieve synergistic cancer therapy. Methods In this study, we successfully synthesized a multifunctional theranostic system, which was developed through FDA-approved self-assembling drugs, which contain anticancer drug doxorubicin (Dox), imaging and high photothermal conversion drug indocyanine green (ICG) and P-gp regulator TPGS (the system named T/Dox-ICG). We studied the characterization of T/Dox-ICG NPs, including the TEM, SEM, DLS, UV-vis-NIR, zeta potential, CLSM, in vitro FL imaging, in vitro photothermal effect, in vitro Dox and ICG release. We used CLSM to verify the location of intracellular distribution of Dox in SCG 7901/VCR cells, Western blot was performed to demonstrate the TPGS-mediated inhibition of P-gp. And, the cytotoxicity of materials against SCG 7901/VCR cells was studied by the MTT assay. Results The TEM showed the T/Dox-ICG NPs had good monodispersity with diameters of 19.03 nm, Dox and ICG could be released constantly from T/Dox-ICG NPs in vitro. In vitro cell experiments demonstrated higher Dox accumulation and retention in the nucleus. Western blot showed TPGS could obviously inhibit the expression of P-gp. In vitro cytotoxicity assay showed more significant cytotoxicity on MDR cells (SCG 7901/VCR) with only 8.75% of cells surviving. Conclusion MDR cancer therapy indicates that it may be important to develop a safer system that can simultaneously inhibit the drug transporters and monitor the delivery of chemotherapeutic agents, and combination therapy have raised widespread concern on tumor treatment.
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Affiliation(s)
- Haiyan Gao
- Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou 450003, People's Republic of China.,Henan Key Laboratory of Neurological Imaging, Zhengzhou University, Zhengzhou 450003, People's Republic of China
| | - Yan Bai
- Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou 450003, People's Republic of China.,Henan Key Laboratory of Neurological Imaging, Zhengzhou University, Zhengzhou 450003, People's Republic of China
| | - Lijuan Chen
- Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou 450003, People's Republic of China.,Henan Key Laboratory of Neurological Imaging, Zhengzhou University, Zhengzhou 450003, People's Republic of China
| | - Georges Ei Fakhri
- Gordon Center for Medical Imaging, Radiology, Massachusettes General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Meiyun Wang
- Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou 450003, People's Republic of China.,Henan Key Laboratory of Neurological Imaging, Zhengzhou University, Zhengzhou 450003, People's Republic of China
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16
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Jiang X, Fan X, Xu W, Zhang R, Wu G. Biosynthesis of Bimetallic Au–Ag Nanoparticles Using Escherichia coli and its Biomedical Applications. ACS Biomater Sci Eng 2019; 6:680-689. [DOI: 10.1021/acsbiomaterials.9b01297] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Xinglu Jiang
- Medical School of Southeast University, Nanjing 210009, People’s Republic of China
| | - Xiaobo Fan
- Medical School of Southeast University, Nanjing 210009, People’s Republic of China
| | - Wei Xu
- Medical School of Southeast University, Nanjing 210009, People’s Republic of China
| | - Rui Zhang
- Medical School of Southeast University, Nanjing 210009, People’s Republic of China
| | - Guoqiu Wu
- Center of Clinical Laboratory Medicine, Zhongda Hospital, Southeast University, Nanjing 210009, People’s Republic of China
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17
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Nourmohammadi E, Mahoonak AS. Health Implications of Bioactive Peptides: A Review. INT J VITAM NUTR RES 2018; 88:319-343. [DOI: 10.1024/0300-9831/a000418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Abstract. Today, due to immobility, improper food habits, and changes in lifestyle, communities are faced with an increase in health problems such as blood pressure, cholesterol, diabetes, and thrombosis. Bioactive peptides are considered as being the main products of protein hydrolysis which exert high effects on the nervous, immune, and gastrointestinal systems. Unlike synthetic drugs, bioactive peptides have no side effects and this advantage has qualified them as an alternative to such drugs. Due to the above-mentioned properties, this paper focuses on the study of health-improving attributes of bioactive peptides such as anti-oxidative, anti-hypertensive, immunomodulatory, anti-microbial, anti-allergenic, opioid, anti-thrombotic, mineral-binding, anti-inflammatory, hypocholesterolemic, and anti-cancer effects. We also discuss the formation of bioactive peptides during fermentation, the main restrictions on the use of bioactive peptides and their applications in the field of functional foods. In general, food-derived biologically active peptides play an important role in human health and may be used in the development of novel foods with certain health claims.
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Affiliation(s)
- Elham Nourmohammadi
- Department of Food Science and Technology, Gorgan University of Agricultural Science & Natural Resources, Gorgan, Iran
| | - Alireza Sadeghi Mahoonak
- Department of Food Science and Technology, Gorgan University of Agricultural Science & Natural Resources, Gorgan, Iran
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18
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Structure and Interactions of A Host Defense Antimicrobial Peptide Thanatin in Lipopolysaccharide Micelles Reveal Mechanism of Bacterial Cell Agglutination. Sci Rep 2017; 7:17795. [PMID: 29259246 PMCID: PMC5736615 DOI: 10.1038/s41598-017-18102-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/05/2017] [Indexed: 12/15/2022] Open
Abstract
Host defense cationic Antimicrobial Peptides (AMPs) can kill microorganisms including bacteria, viruses and fungi using various modes of action. The negatively charged bacterial membranes serve as a key target for many AMPs. Bacterial cell death by membrane permeabilization has been well perceived. A number of cationic AMPs kill bacteria by cell agglutination which is a distinctly different mode of action compared to membrane pore formation. However, mechanism of cell agglutinating AMPs is poorly understood. The outer membrane lipopolysaccharide (LPS) or the cell-wall peptidoglycans are targeted by AMPs as a key step in agglutination process. Here, we report the first atomic-resolution structure of thanatin, a cell agglutinating AMP, in complex with LPS micelle by solution NMR. The structure of thanatin in complex with LPS, revealed four stranded antiparallel β-sheet in a ‘head-tail’ dimeric topology. By contrast, thanatin in free solution assumed an antiparallel β-hairpin conformation. Dimeric structure of thanatin displayed higher hydrophobicity and cationicity with sites of LPS interactions. MD simulations and biophysical interactions analyses provided mode of LPS recognition and perturbation of LPS micelle structures. Mechanistic insights of bacterial cell agglutination obtained in this study can be utilized to develop antibiotics of alternative mode of action.
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19
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Yang N, Liu X, Teng D, Li Z, Wang X, Mao R, Wang X, Hao Y, Wang J. Antibacterial and detoxifying activity of NZ17074 analogues with multi-layers of selective antimicrobial actions against Escherichia coli and Salmonella enteritidis. Sci Rep 2017; 7:3392. [PMID: 28611436 PMCID: PMC5469750 DOI: 10.1038/s41598-017-03664-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/25/2017] [Indexed: 01/09/2023] Open
Abstract
NZ17074 (N1), an arenicin-3 derivative isolated from the lugworm, has potent antibacterial activity and is cytotoxic. To reduce its cytotoxicity, seven N1 analogues with different structures were designed by changing their disulfide bonds, hydrophobicity, or charge. The “rocket” analogue-N2 and the “kite” analogue-N6 have potent activity and showed lower cytotoxicity in RAW264.7 cells than N1. The NMR spectra revealed that N1, N2, and N6 adopt β-sheet structures stabilized by one or two disulfide bonds. N2 and N6 permeabilized the outer/inner membranes of E. coli, but did not permeabilize the inner membranes of S. enteritidis. N2 and N6 induced E. coli and S. enteritidis cell cycle arrest in the I-phase and R-phase, respectively. In E. coli and in S. enteritidis, 18.7–43.8% of DNA/RNA/cell wall synthesis and 5.7–61.8% of DNA/RNA/protein synthesis were inhibited by the two peptides, respectively. Collapsed and filamentous E. coli cells and intact morphologies of S. enteritidis cells were observed after treatment with the two peptides. Body weight doses from 2.5–7.5 mg/kg of N2 and N6 enhanced the survival rate of peritonitis- and endotoxemia-induced mice; reduced the serum IL-6, IL-1β and TNF-α levels; and protected mice from lipopolysaccharide-induced lung injury. These data indicate that N2 and N6, through multiple selective actions, may be promising dual-function candidates as novel antimicrobial and anti-endotoxin peptides.
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Affiliation(s)
- Na Yang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xuehui Liu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Da Teng
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhanzhan Li
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiumin Wang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China. .,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Ruoyu Mao
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiao Wang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ya Hao
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China.,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jianhua Wang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China. .,Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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20
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Fan X, Fan J, Wang X, Wu P, Wu G. S-thanatin functionalized liposome potentially targeting on Klebsiella pneumoniae and its application in sepsis mouse model. Front Pharmacol 2015; 6:249. [PMID: 26578959 PMCID: PMC4621865 DOI: 10.3389/fphar.2015.00249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/12/2015] [Indexed: 11/13/2022] Open
Abstract
S-thanatin (Ts) was a short antimicrobial peptide with selective antibacterial activity. In this study, we aimed to design a drug carrier with specific bacterial targeting potential. The positively charged Ts was modified onto the liposome surface by linking Ts to the constituent lipids via a PEG linker. The benefits of this design were evaluated by preparing a series of liposomes and comparing their biological effects in vitro and in vivo. The particle size and Zeta potential of the constructed liposomes were measured with a Zetasizer Nano ZS system and a confocal laser scanning microscope. The in vitro drug delivery potential was evaluated by measuring the cellular uptake of encapsulated levofloxacin using HPLC. Ts-linked liposome or its conjugates with quantum dots favored bacterial cells, and increased the bacterial uptake of levofloxacin. In antimicrobial assays, the Ts and levofloxacin combination showed a synergistic effect, and Ts-LPs-LEV exhibited excellent activity against the quality control stain Klebsiella pneumoniae ATCC 700603 and restored the susceptibility of multidrug-resistant K. pneumoniae clinical isolates to levofloxacin in vitro. Furthermore, Ts-LPs-LEV markedly reduced the lethality rate of the septic shock and resulted in rapid bacterial clearance in mouse models receiving clinical multidrug resistant (MDR) isolates. These results suggest that the Ts-functionalized liposome may be a promising antibiotic delivery system for clinical infectious disorders caused by MDR bacteria, in particular the sepsis related diseases.
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Affiliation(s)
- Xiaobo Fan
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast UniversityNanjing, China
- Medical School, Southeast UniversityNanjing, China
| | - Juxiang Fan
- Medical School, Southeast UniversityNanjing, China
| | - Xiyong Wang
- Medical School, Southeast UniversityNanjing, China
| | - Pengpeng Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast UniversityNanjing, China
| | - Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast UniversityNanjing, China
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21
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Robert É, Lefèvre T, Fillion M, Martial B, Dionne J, Auger M. Mimicking and Understanding the Agglutination Effect of the Antimicrobial Peptide Thanatin Using Model Phospholipid Vesicles. Biochemistry 2015; 54:3932-41. [PMID: 26057537 DOI: 10.1021/acs.biochem.5b00442] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thanatin is a cationic 21-residue antimicrobial and antifongical peptide found in the spined soldier bug Podisus maculiventris. It is believed that it does not permeabilize membranes but rather induces the agglutination of bacteria and inhibits cellular respiration. To clarify its mode of action, lipid vesicle organization and aggregation propensity as well as peptide secondary structure have been studied using different membrane models. Dynamic light scattering and turbidimetry results show that specific mixtures of negatively charged and zwitterionic phospholipid vesicles are able to mimic the agglutination effect of thanatin observed on Gram-negative and Gram-positive bacterial cells, while monoconstituent ("conventional") models cannot reproduce this phenomenon. The model of eukaryotic cell reveals no particular interaction with thanatin, which is consistent with the literature. Infrared spectroscopy shows that under the conditions under which vesicle agglutination occurs, thanatin exhibits a particular spectral pattern in the amide I' region and in the region associated with Arg side chains. The data suggest that thanatin mainly retains its hairpin structure, Arg residues being involved in strong interactions with anionic groups of phospholipids. In the absence of vesicle agglutination, the peptide conformation and Arg side-chain environment are similar to those observed in solution. The data show that a negatively charged membrane is required for thanatin to be active, but this condition is insufficient. The activity of thanatin seems to be modulated by the charge surface density of membranes and thanatin concentration.
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Affiliation(s)
- Émile Robert
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
| | - Thierry Lefèvre
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
| | - Matthieu Fillion
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
| | - Benjamin Martial
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
| | - Justine Dionne
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, Canada G1V 0A6
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22
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Wang L, Zhang H, Jia Z, Ma Q, Dong N, Shan A. In vitro and in vivo activity of the dimer of PMAP-36 expressed in Pichia pastoris. J Mol Microbiol Biotechnol 2014; 24:234-40. [PMID: 25196715 DOI: 10.1159/000365572] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The antimicrobial peptide PMAP-36 exists as a homodimer stabilized by an intermolecular disulfide bridge. The dimer of PMAP-36 exhibits a potent and rapid microbicidal activity against a wide spectrum of microorganisms. The gene encoding the antiparallel dimer (PMAP-36)2 was designed and codon-optimized according to bias of Pichia pastoris. The gene was then expressed in the P. pastoris strain GS115. The concentration of the recombinant product reached 106 mg/l. In vitro activity assays indicated that the recombinant peptide showed antimicrobial activities against Gram-positive and Gram-negative bacteria but did not cause hemolysis of chicken erythrocytes. Subsequently, 120 7-day-old male Arbor Acres broilers were used to evaluate the in vivo activities of the peptide. A prophylactic dose of ciprofloxacin lactate was supplemented as the control. The results showed that recombinant (PMAP-36)2 significantly increased the serum IgM content of the birds (p < 0.05). The recombinant peptide significantly increased the amounts of Bifidobacterium and decreased the amount of Escherichia coli cells in the ceca of the experimental birds (p < 0.05). The results obtained in the present study indicate that the recombinant (PMAP-36)2 has a potent in vitro and in vivo activity and can be used as an alternative to antibiotic treatment.
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Affiliation(s)
- Liang Wang
- Laboratory of Molecular Nutrition and Immunity, Institute of Animal Nutrition, Northeast Agricultural University, Harbin, PR China
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23
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Depolymerase improves gentamicin efficacy during Klebsiella pneumoniae induced murine infection. BMC Infect Dis 2014; 14:456. [PMID: 25149315 PMCID: PMC4150946 DOI: 10.1186/1471-2334-14-456] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 08/19/2014] [Indexed: 12/19/2022] Open
Abstract
Background Presence of capsule enhances the virulence of bacteria that cause pneumonia, meningitis, cystic fibrosis, dental caries, periodontitis. Capsule is an important virulence factor for Klebsiella pneumoniae and infections due to this pathogen have been associated with high mortality rates. In the present study, use of an Aeromonas punctata derived capsule depolymerase against K. pneumoniae, to reinstate the efficacy of gentamicin during pneumonia and septicemia was investigated. Methods Depolymerase was administered in mice intraperitoneally (50 μg) alone as well in combination with gentamicin (1.5 mg/kg), 24 h post infection during acute lung infection and 6 h later during septicemia. Bacterial load, neutrophil infiltration and cytokine levels were estimated. The immunogenicity of protein was also studied. Results In comparison to groups treated with gentamicin alone, combination treatment with depolymerase and gentamicin significantly reduced (P < 0.01) bacterial titer in the lungs, liver, kidney, spleen and blood of experimental animals. Highly significant reduction in neutrophil infiltration and levels of pro-inflammatory and anti-inflammatory cytokines was also observed. This indicated an efficient capsule removal by the enzyme, that improved gentamicin efficacy in vivo. Although the enzyme was found to be immunogenic, but no significant reduction in treatment efficacy was observed in the preimmunized as well as naïve mice. In addition, as confirmed through flow cytometry, the hyperimmune sera raised against the enzyme did not neutralize its activity. Conclusion The results confirm that administration of enzyme ‘depolymerase’ along with gentamicin not only checked the virulence of K. pneumoniae in vivo but it also increased its susceptibility to gentamicin at a lower concentration. Such a strategy would help to avoid exposure to higher concentration of gentamicin. Moreover, since this decapsulating protein does not possess a lytic activity therefore there would be no chances of development of bacterial resistance against it. Therefore, it should be studied further for its successful inclusion in our prophylactic/therapeutic regimes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2334-14-456) contains supplementary material, which is available to authorized users.
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24
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Wu G, Wu P, Xue X, Yan X, Liu S, Zhang C, Shen Z, Xi T. Application of S-thanatin, an antimicrobial peptide derived from thanatin, in mouse model of Klebsiella pneumoniae infection. Peptides 2013; 45:73-7. [PMID: 23643614 DOI: 10.1016/j.peptides.2013.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 04/19/2013] [Accepted: 04/19/2013] [Indexed: 10/26/2022]
Abstract
Thanatin was first discovered from the hemipteran insect Podisus maculiventris and showed a promising antimicrobial activity. Multidrug-resistant (MDR) clinical isolates of Klebsiella pneumoniae have developed resistance to current therapies. As an attempt to resolve this problem, the efficacy of thanatin and its analogues against clinical isolates of K. pneumoniae was studied in vitro and in vivo. S-thanatin showed an improved antimicrobial activity with the tested MIC values was 2-8-fold lower than those of other thanatin analogs. Antimicrobial assay indicated a high activity of S-thanatin against K. pneumoniae in vitro with MIC between 4 and 8 μg/ml. Its in vivo activity was evaluated using a K. pneumoniae-infected mice model. Adult male ICR mice were randomly grouped and given an intraperitoneal (i.p.) administration of 2 × 10(10)colony-forming units of K. pneumoniae (CI 120204205). Afterwards, mouse groups were subjected to i.p. administration of saline or S-thanatin (5, 10, or 15 mg/kg). After an inspection of 72 h, the mice were finally sacrificed for analysis of in vivo bacterial growth and plasma endotoxin level. The results showed that S-thanatin administration apparently improved the survival rate and reduced the bacterial CFU from intra-abdominal fluid in mice. The plasma endotoxin level was improved as well. All above implied that S-thanatin, as an alternative, may provide a novel strategy for treating K. pneumoniae infection and other infections due to multidrug-resistant bacteria.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast University, Nanjing 210009, China.
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Schuerholz T, Doemming S, Hornef M, Martin L, Simon TP, Heinbockel L, Brandenburg K, Marx G. The anti-inflammatory effect of the synthetic antimicrobial peptide 19-2.5 in a murine sepsis model: a prospective randomized study. Crit Care 2013; 17:R3. [PMID: 23302299 PMCID: PMC4057408 DOI: 10.1186/cc11920] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 01/07/2013] [Indexed: 11/16/2022] Open
Abstract
Introduction Increasing rates of multi-resistant bacteria are a major problem in the treatment of critically ill patients. Furthermore, conventional antibiotics lead to the release of bacterial derived membrane parts initiating pro-inflammatory cascades with potential harm to the patient. Antimicrobial peptides (AMP) may kill bacteria without releasing pro-inflammatory factors. Thus, we compared three newly developed synthetic anti-lipopolysaccharide peptides (SALPs) with a broader range of efficacy to suppress cytokine release in plasma and CD14 mRNA expression in organ tissue in a murine, polymicrobial sepsis model. Methods A randomized, experimental trial was conducted in an animal research facility. Male NMRI mice (n = 90; 8- to 12-weeks old) were randomized to the following six groups: (i) sham operation and parenteral vehicle (NaCl 0.9%) administration (sham); (ii) cecal ligation and puncture (CLP) and vehicle infusion (sepsis-control), (iii) CLP and polymyxin B infusion (polyB), or (iv to vi) CLP and infusion of three different synthetic antimicrobial peptides Peptide 19-2.5 (Pep2.5), Peptide 19-4 (Pep4) or Peptide 19-8 (Pep8). All animals underwent arterial and venous catheterization for hemodynamic monitoring 48 hours prior to CLP or sham-operation. Physical appearance and behavior (activity), plasma cytokine levels, and CD14 mRNA expression in heart, lung, liver, spleen and kidney tissue were determined 24 hours after CLP or sham operation. Results Only Pep2.5 significantly enhanced the activity after CLP, whereas none of the therapeutic regimens elevated the mean arterial pressure or heart rate. The strongly elevated IL-6, IL-10 and monocyte chemoattractant protein serum levels in septic animals were significantly reduced after Pep2.5 administration (P < 0.001, P < 0.001, and P < 0.001, respectively). Similarly, Pep2.5 significantly reduced the sepsis-induced CD14 mRNA expression in heart (P = 0.003), lung (P = 0.008), and spleen tissue (P = 0.009) but not in kidney and liver. Conclusions Structurally variable SALPs exhibit major differences in their anti-inflammatory effect in vivo. Continuous parenteral administration of Pep2.5 is able to reduce sepsis-induced cytokine release and tissue inflammation.
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Schuerholz T, Brandenburg K, Marx G. Antimicrobial peptides and their potential application in inflammation and sepsis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:207. [PMID: 22429567 PMCID: PMC3681352 DOI: 10.1186/cc11220] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Tobias Schuerholz
- Department of Intensive Care, University Hospital, Pauwelsstr. 30, 52074 Aachen, Germany.
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Wu G, Deng X, Wu P, Shen Z, Xu H. Subacute toxicity of antimicrobial peptide S-thanatin in ICR mice. Peptides 2012; 36:109-13. [PMID: 22537943 DOI: 10.1016/j.peptides.2012.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 04/07/2012] [Accepted: 04/09/2012] [Indexed: 11/26/2022]
Abstract
Antibiotics are commonly used for infectious diseases and saved a lot of lives since its discovery, but the emergence of drug-resistant microorganism has brought a tremendous challenge to clinical therapy at present. Antimicrobial peptides, which are of broad antimicrobial spectrum and rare resistance development in pathogens, are expected to replace conventional antibiotics. S-thanatin, a novel antimicrobial peptide with 21 amino acid residues, was proved of significant benefit on therapy of pathogens infection. To evaluate the security of S-thanatin, its subacute toxicity was examined in ICR mice by continually intravenous injection with 125, 50, 20 mg/kg (1/4, 1/10, 1/25 LD(50)) or saline with equal volume for two weeks. Results demonstrated that neither significant difference of serum chemistry and hematology, nor pathological changes were changed in major organs caused by S-thanatin between groups. In conclusion, S-thanatin appears to be a safe antimicrobial peptide for further preclinical trials.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast University, Nanjing 210009, China.
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Wu G, Wang X, Deng G, Wu L, Ju S, Teng G, Yao Y, Wang X, Liu N. Novel peptide targeting integrin αvβ3-rich tumor cells by magnetic resonance imaging. J Magn Reson Imaging 2012; 34:395-402. [PMID: 21780231 DOI: 10.1002/jmri.22620] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To investigate the targeting activity of the peptide (named P1c) derived from connective tissue growth factor (CTGF) to αvβ3-rich tumor cells. MATERIALS AND METHODS P1c was synthesized and conjugated with ultrasuperparamagnetic iron oxide particles (USPIOs) coated with meso-2,3-dimercaptosuccinic acid (DMSA). The specific binding activity of P1c-USPIOs to αvβ3 was verified by solid phase binding assay. The combination of P1c-USPIOs with a human primary liver cancer cell (Bel 7402) with αvβ3-positive expression and uptake of P1c-USPIOs by cells was investigated by Prussian blue staining, transmission electron microscopy (TEM), and magnetic resonance imaging (MRI). The targeting activity of the probe in vivo was also evaluated using a small-animal tumor model by MRI. RESULTS The cell uptake of P1c-USPIOs was observed in a dose-dependent manner, whereas no significant particle uptake was found in the plain USPIOs group. The differences on T2*-weighted imaging were also found by MRI and the signal intensity (SI) was statistically reduced after coculture of Bel 7402 cells with P1c-USPIOs at a concentration of 20-80 μg/mL compared with plain USPIOs (P < 0.05). The in vivo study showed that the signal reduction was distributed mainly in the periphery and some central areas of the tumor. The tumor-to-muscle CNR (contrast-to-noise ratio) at 12 hours after the administration of the P1c-USPIOs was statistically significantly different compared to those at 0 hour, 1 hour, or the plain USPIO group (P < 0.05). CONCLUSION The peptide P1c might be a good candidate as a targeting carrier for drugs or tracers.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Institute of Biotechnology and Clinical Pharmacy, Southeast University, Nanjing, China.
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Lu X, Shen J, Jin X, Ma Y, Huang Y, Mei H, Chu F, Zhu J. Bactericidal activity of Musca domestica cecropin (Mdc) on multidrug-resistant clinical isolate of Escherichia coli. Appl Microbiol Biotechnol 2011; 95:939-45. [DOI: 10.1007/s00253-011-3793-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/21/2011] [Accepted: 11/24/2011] [Indexed: 11/29/2022]
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Wu G, Deng X, Li X, Wang X, Wang S, Xu H. Application of immobilized thrombin for production of S-thanatin expressed in Escherichia coli. Appl Microbiol Biotechnol 2011; 92:85-93. [PMID: 21655979 DOI: 10.1007/s00253-011-3379-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 05/06/2011] [Accepted: 05/07/2011] [Indexed: 11/28/2022]
Abstract
S-thanatin, a small antimicrobial peptide with 21 amino acid residues, was expressed as a fusion protein containing thrombin cleavage site in Escherichia coli BL21 (DE3). To reduce the production cost, immobilization of thrombin in polyacrylamide gel for cleavage was studied in this work. The immobilized thrombin exhibited excellent activity within wider ranges of pH value and temperature for reaction than free enzyme, and the residual activity could remain above 75% after ten times of usage. Tricine-SDS-PAGE result showed that the immobilized thrombin could cleave the S-thanatin fusion protein effectively. After cleavage, recombinant S-thanatin was purified by preparative reversed-phase high-performance liquid chromatography and mass spectrum showed that the molecular weight (2,448.86) was close to the theoretical value (2,448.98). After purification, about 7 mg of S-thanatin was obtained from 1 l of culture and the recombinant exhibited excellent bioactivity to E. coli ATCC 25922, with the minimum inhibitory concentration of 12 μg/ml. The purification method could be applied to prepare other peptides with similar properties at low cost.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast University, Nanjing, China.
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Wu G, Li X, Fan X, Wu H, Wang S, Shen Z, Xi T. The activity of antimicrobial peptide S-thanatin is independent on multidrug-resistant spectrum of bacteria. Peptides 2011; 32:1139-45. [PMID: 21453736 DOI: 10.1016/j.peptides.2011.03.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 03/17/2011] [Accepted: 03/17/2011] [Indexed: 11/21/2022]
Abstract
In this study, the activity of S-thanatin (an analog of antimicrobial peptide derived from thanatin) against different bacterial pathogens frequently which can cause therapeutic problems was tested. The result showed minimal inhibitory concentrations (MICs) of S-thanatin against all isolates of the Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes, Klebsiella ornithinolytica and Klebsiella oxytoca were in the range of 4-16μg/ml, no matter which antibiotic the bacterial was resistant or susceptible, while almost all MICs to Gram-positive bacterial were >128μg/ml except Enterococcus faecium. S-thanatin was more effective toward Gram-negative strains, especially for Enterobacter and Klebsiella. The MICs of S-thanatin were no significantly different in the same species regardless of antibiotic sensitive or -resistant isolates to single or multiple antibiotic (P>0.05). Likewise, no notable difference could be observed between E. coli, K. pneumoniae, E. cloacae, E. aerogenes, K. ornithinolytica which were sensitive to S-thanatin (P>0.05). It was implied that the antimicrobial activity of S-thanatin was independent on multi-drug resistance spectrum of bacteria.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast University, Nanjing 210009, China.
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Wu G, Li X, Deng X, Fan X, Wang S, Shen Z, Xi T. Protective effects of antimicrobial peptide S-thanatin against endotoxic shock in mice introduced by LPS. Peptides 2011; 32:353-7. [PMID: 21050874 DOI: 10.1016/j.peptides.2010.10.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 10/25/2010] [Accepted: 10/25/2010] [Indexed: 11/19/2022]
Abstract
Sepsis continues to be a major unresolved medical challenge of the present. Severe sepsis and septic shock are the leading causes of multiple organ failure and mortality in noncoronary intensive care units (ICUs). The primary reason of septic shock is the activation of host effecter cells by endotoxin and lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the key point of treatment is removing LPS. S-thanatin (Ts), an analog of thanatin, was synthesized by substituting the 15th amino acid of threonine with serine, which showed a broad antimicrobial activity against gram-negative and gram-positive bacteria. We have reported its LPS-binding and -neutralizing activity in vitro. The aim of this study is to examine the LPS-neutralizing activities and the protective effects of S-thanatin in vivo. Every mice was injected intraperitoneally with LPS (from Escherichia coli O111:B4) 150μg before injected intraperitoneally or vena caudalis with 3mg/kg, 6mg/kg and 12mg/kg, and measured endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, as well as lethality. The results showed that S-thanatin can significantly reduce endotoxin and TNF-α level in plasma, at the same time resulting in the highest survival rates.
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Affiliation(s)
- Guoqiu Wu
- Southeast University, Nanjing, People's Republic of China. guoqiu
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Wu G, Wu H, Fan X, Zhao R, Li X, Wang S, Ma Y, Shen Z, Xi T. Selective toxicity of antimicrobial peptide S-thanatin on bacteria. Peptides 2010; 31:1669-73. [PMID: 20600431 DOI: 10.1016/j.peptides.2010.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 06/13/2010] [Accepted: 06/14/2010] [Indexed: 11/18/2022]
Abstract
S-thanatin, an analog of thanatin, was synthesized by substituting the 15th amino acid of threonine with serine, which showed a broad antimicrobial activity against bacteria. We reported earlier that membrane phospholipid was found to be the target for S-thanatin with different mechanism from other antimicrobial peptides. In this study, we have performed its structural characterization by circular dichroism (CD) spectroscopy. The CD analysis showed that S-thanatin retained its overall conformation beta-sheet in aqueous buffer, beta-turn in 50% trifluoroethanol (TFE) and beta-hairpin in 0.4 mM POPC-LUVs. In hemolysis assay, S-thanatin exhibited low hemolytic activity and bacteria selectivity. We investigated the effect of the presence of 33 mol percent cholesterol on the interactions of the antimicrobial peptide S-thanatin with phosphatidylcholine (PC) model membrane systems. The results showed that S-thanatin was more potent at disrupting cholesterol-free bacterial than cholesterol-containing eukaryotic membranes. Thus, in all respects, fluorescence dye leakage experiments indicated that cholesterol inhibited the S-thanatin-induced permeabilization of PC vesicles. Finally, flow cytometry was used to monitor changes in bacterial cell membrane potential and cell membrane integrity, with specific fluorescent dyes DiBAC(4)(3) and PI. Adding the respiratory poison CCCP seemed to prevent peptide-induced membrane damage, which suggested that S-thanatin acted at the metabolic level on respiratory chain. These findings might explain why S-thanatin was selective toxicity towards bacteria, but low toxicity towards erythrocytes. It might be due to three factors at least: electrostatic interaction (namely anionic phospholipids); cholesterol; respiratory chain.
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Affiliation(s)
- Guoqiu Wu
- Center of Clinical Laboratory Medicine of Zhongda Hospital, Southeast University, Nanjing 210009, PR China.
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