1
|
Gupta LK, Molla J, Prabhu AA. Story of Pore-Forming Proteins from Deadly Disease-Causing Agents to Modern Applications with Evolutionary Significance. Mol Biotechnol 2024; 66:1327-1356. [PMID: 37294530 DOI: 10.1007/s12033-023-00776-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/21/2023] [Indexed: 06/10/2023]
Abstract
Animal venoms are a complex mixture of highly specialized toxic molecules. Among them, pore-forming proteins (PFPs) or toxins (PFTs) are one of the major disease-causing toxic elements. The ability of the PFPs in defense and toxicity through pore formation on the host cell surface makes them unique among the toxin proteins. These features made them attractive for academic and research purposes for years in the areas of microbiology as well as structural biology. All the PFPs share a common mechanism of action for the attack of host cells and pore formation in which the selected pore-forming motifs of the host cell membrane-bound protein molecules drive to the lipid bilayer of the cell membrane and eventually produces water-filled pores. But surprisingly their sequence similarity is very poor. Their existence can be seen both in a soluble state and also in transmembrane complexes in the cell membrane. PFPs are prevalent toxic factors that are predominately produced by all kingdoms of life such as virulence bacteria, nematodes, fungi, protozoan parasites, frogs, plants, and also from higher organisms. Nowadays, multiple approaches to applications of PFPs have been conducted by researchers both in basic as well as applied biological research. Although PFPs are very devastating for human health nowadays researchers have been successful in making these toxic proteins into therapeutics through the preparation of immunotoxins. We have discussed the structural, and functional mechanism of action, evolutionary significance through dendrogram, domain organization, and practical applications for various approaches. This review aims to emphasize the PFTs to summarize toxic proteins together for basic knowledge as well as to highlight the current challenges, and literature gap along with the perspective of promising biotechnological applications for their future research.
Collapse
Affiliation(s)
- Laxmi Kumari Gupta
- Bioprocess Development Laboratory, Department of Biotechnology, National Institute of Technology Warangal, Warangal, Telangana, 506004, India
| | - Johiruddin Molla
- Ghatal Rabindra Satabarsiki Mahavidyalaya Ghatal, Paschim Medinipur, Ghatal, West Bengal, 721212, India
| | - Ashish A Prabhu
- Bioprocess Development Laboratory, Department of Biotechnology, National Institute of Technology Warangal, Warangal, Telangana, 506004, India.
| |
Collapse
|
2
|
Sabino YNV, de Araújo Domingues KC, O'Connor PM, Marques PH, Santos EH, Tótola MR, Abreu LM, de Queiroz MV, Cotter PD, Mantovani HC. Bacillus velezensis iturins inhibit the hemolytic activity of Staphylococcus aureus. Sci Rep 2024; 14:9469. [PMID: 38658583 PMCID: PMC11043418 DOI: 10.1038/s41598-024-58973-0] [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: 09/08/2023] [Accepted: 04/05/2024] [Indexed: 04/26/2024] Open
Abstract
Bovine mastitis caused by S. aureus has a major economic impact on the dairy sector. With the crucial need for new therapies, anti-virulence strategies have gained attention as alternatives to antibiotics. Here we aimed to identify novel compounds that inhibit the production/activity of hemolysins, a virulence factor of S. aureus associated with mastitis severity. We screened Bacillus strains obtained from diverse sources for compounds showing anti-hemolytic activity. Our results demonstrate that lipopeptides produced by Bacillus spp. completely prevented the hemolytic activity of S. aureus at certain concentrations. Following purification, both iturins, fengycins, and surfactins were able to reduce hemolysis caused by S. aureus, with iturins showing the highest anti-hemolytic activity (up to 76% reduction). The lipopeptides showed an effect at the post-translational level. Molecular docking simulations demonstrated that these compounds can bind to hemolysin, possibly interfering with enzyme action. Lastly, molecular dynamics analysis indicated general stability of important residues for hemolysin activity as well as the presence of hydrogen bonds between iturins and these residues, with longevous interactions. Our data reveals, for the first time, an anti-hemolytic activity of lipopeptides and highlights the potential application of iturins as an anti-virulence therapy to control bovine mastitis caused by S. aureus.
Collapse
Affiliation(s)
| | | | | | - Pedro Henrique Marques
- Department of Microbiology, Immunology and Parasitology, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Eduardo Horta Santos
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | | | - Paul D Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Cork, Ireland
- APC Microbiome Ireland, Cork, Ireland
| | | |
Collapse
|
3
|
Sardaru MC, Rosca I, Ursu C, Dascalu IA, Ursu EL, Morariu S, Rotaru A. Photothermal Hydrogel Composites Featuring G4-Carbon Nanomaterial Networks for Staphylococcus aureus Inhibition. ACS OMEGA 2024; 9:15833-15844. [PMID: 38617624 PMCID: PMC11007816 DOI: 10.1021/acsomega.3c07724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 03/06/2024] [Accepted: 03/20/2024] [Indexed: 04/16/2024]
Abstract
Microbial infections represent a significant health risk, often leading to severe complications and, in some cases, even fatalities. As a result, there is an urgent need to explore innovative drug delivery systems and alternative therapeutic techniques. The photothermal therapy has emerged as a promising antibacterial approach and is the focus of this study. Herein, we report the successful synthesis of two distinct supramolecular composite hydrogels by incorporating graphene oxide (GO) and single-walled carbon nanotubes (SWNTs) into guanosine quadruplex (G4) based hydrogels containing covalently bound β-cyclodextrin (β-CD). The G4 matrix was synthesized through a two-step process, establishing a robust network between G4 and β-CDs, followed by the encapsulation of either GO or SWNTs. Comprehensive characterization of these composite hydrogels were conducted using analytical techniques, including circular dichroism, Raman spectroscopy, rheological investigations, X-ray diffraction, and scanning electron microscopy. A notable discovery from the conducted research is the differential photothermal responses exhibited by the hydrogels when exposed to near-infrared laser irradiation. Specifically, SWNT-based hydrogels demonstrated superior photothermal performance, achieving a remarkable temperature increase of up to 52 °C, in contrast to GO-based hydrogels, which reached a maximum of 34 °C. These composite hydrogels showed good cytotoxicity evaluation results and displayed synergistic antibacterial activity against Staphylococcus aureus, positioning them as promising candidates for antibacterial photothermic platforms, particularly in the context of wound treatment. This study offers a valuable contribution to the development of advanced and combined therapeutic strategies for combating microbial infections and highlights the potential of carbon nanomaterial-enhanced supramolecular hydrogels in photothermal therapy applications.
Collapse
Affiliation(s)
- Monica-Cornelia Sardaru
- The
Research Institute of the University of Bucharest (ICUB), 90 Sos. Panduri, 050663 Bucharest, Romania
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Centre of Advanced Research in Bionanoconjugates and
Biopolymers, Grigore
Ghica Voda Alley 41 A, 700487 Iasi, Romania
| | - Irina Rosca
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Centre of Advanced Research in Bionanoconjugates and
Biopolymers, Grigore
Ghica Voda Alley 41 A, 700487 Iasi, Romania
| | - Cristian Ursu
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Physics of Polymers and Polymeric Materials Laboratory, Grigore Ghica Voda Alley 41 A, 700487 Iasi, Romania
| | - Ioan-Andrei Dascalu
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Centre of Advanced Research in Bionanoconjugates and
Biopolymers, Grigore
Ghica Voda Alley 41 A, 700487 Iasi, Romania
| | - Elena-Laura Ursu
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Centre of Advanced Research in Bionanoconjugates and
Biopolymers, Grigore
Ghica Voda Alley 41 A, 700487 Iasi, Romania
| | - Simona Morariu
- Natural
Polymers, Bioactive and Biocompatible Materials, “Petru Poni” Institute of Macromolecular Chemistry,
Romanian Academy, Grigore
Ghica Voda Alley 41 A, Iasi 700487, Romania
| | - Alexandru Rotaru
- “Petru
Poni” Institute of Macromolecular Chemistry, Romanian Academy, Centre of Advanced Research in Bionanoconjugates and
Biopolymers, Grigore
Ghica Voda Alley 41 A, 700487 Iasi, Romania
| |
Collapse
|
4
|
Magnifico I, Perna A, Cutuli MA, Medoro A, Pietrangelo L, Guarnieri A, Foderà E, Passarella D, Venditti N, Vergalito F, Petronio Petronio G, Di Marco R. A Wall Fragment of Cutibacterium acnes Preserves Junctional Integrity Altered by Staphylococcus aureus in an Ex Vivo Porcine Skin Model. Pharmaceutics 2023; 15:pharmaceutics15041224. [PMID: 37111709 PMCID: PMC10145065 DOI: 10.3390/pharmaceutics15041224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/07/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
(1) Background alteration of the skin microbiota, dysbiosis, causes skin barrier impairment resulting in disease development. Staphylococcus aureus, the main pathogen associated with dysbiosis, secretes several virulence factors, including α-toxin that damages tight junctions and compromises the integrity of the skin barrier. The use of members of the resident microbiota to restore the skin barrier, bacteriotherapy, represents a safe treatment for skin conditions among innovative options. The aim of this study is the evaluation of a wall fragment derived from a patented strain of Cutibacterium acnes DSM28251 (c40) alone and conjugated to a mucopolysaccharide carrier (HAc40) in counteracting S. aureus pathogenic action on two tight junction proteins (Claudin-1 and ZO-1) in an ex vivo porcine skin infection model. Methods: skin biopsies were infected with live S. aureus strains ATCC29213 and DSM20491. Tissue was pre-incubated or co-incubated with c40 and HAc40. (3) Results: c40 and HAc40 prevent and counteract Claudin-1 and Zo-1 damage (4) Conclusions: c40 and the functional ingredient HAc40 represent a potential non-pharmacological treatment of skin diseases associated with cutaneous dysbiosis of S. aureus. These findings offer numerous avenues for new research.
Collapse
Affiliation(s)
- Irene Magnifico
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Angelica Perna
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Marco Alfio Cutuli
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Alessando Medoro
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Laura Pietrangelo
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Antonio Guarnieri
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Emanuele Foderà
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Daniela Passarella
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Noemi Venditti
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Franca Vergalito
- Department of Agricultural, Environmental and Food Sciences (DiAAA), Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Giulio Petronio Petronio
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| | - Roberto Di Marco
- Department of Medicine and Health Science "V. Tiberio", Università degli Studi del Molise, 8600 Campobasso, Italy
| |
Collapse
|
5
|
Electrophysiological and spectroscopic investigation of hydrolysable tannins interaction with α-hemolysin of S. aureus. Bioelectrochemistry 2023; 150:108318. [PMID: 36470005 DOI: 10.1016/j.bioelechem.2022.108318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/04/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022]
Abstract
In this study, using bilayer lipid membrane technique, we report a novel facet of antihemolytic activity of two tannins (1,2,3,4,5-penta-O-galloyl-β-D-glucose (PGG) and 1,2-di-O-galloyl-4,6-valoneoyl-β-D-glucose (dGVG)), which consists in inhibiting the formation of α-hemolysin channels and blocking the conductivity of already formed channels. These effects were observed at tannin concentrations well below minimal inhibitory concentration values for S. aureus growth. Using spectroscopic methods, we show that these two tannins differing in molecular structure but having the same number of -OH groups and aromatic rings form firm complexes with hemolysin in aqueous solutions, which may underlie the disruption of its subsequent interaction with the membrane, thus preventing hemolysis of erythrocytes. In all experimental settings, PGG was the more active compound compared to dGVG, that indicates the important role of the flexibility of the tannin molecule in interaction with the toxin. In addition, we found that PGG, but not dGVG, was able to block the release of the toxin by bacterial cells. This toxin is a strong pathogenic factor causing a number of diseases and therefore is considered as a virulence target for treatment of S. aureus infection, so the data obtained suggest that PGG and possibly other tannins of similar structure have therapeutic potential in fighting the virulence of S. aureus.
Collapse
|
6
|
Sabino YNV, Cotter PD, Mantovani HC. Anti-virulence compounds against Staphylococcus aureus associated with bovine mastitis: A new therapeutic option? Microbiol Res 2023; 271:127345. [PMID: 36889204 DOI: 10.1016/j.micres.2023.127345] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023]
Abstract
Bovine mastitis represents a major economic burden faced by the dairy industry. S. aureus is an important and prevalent bovine mastitis-associated pathogen in dairy farms worldwide. The pathogenicity and persistence of S. aureus in the bovine mammary gland are associated with the expression of a range of virulence factors involved in biofilm formation and the production of several toxins. The traditional therapeutic approach to treating bovine mastitis includes the use of antibiotics, but the emergence of antibiotic-resistant strains has caused therapeutic failure. New therapeutic approaches targeting virulence factors of S. aureus rather than cell viability can have several advantages including lower selective pressure towards the development of resistance and little impact on the host commensal microbiota. This review summarizes the potential of anti-virulence therapies to control S. aureus associated with bovine mastitis focusing on anti-toxin, anti-biofilm, and anti-quorum sensing compounds. It also points to potential sources of new anti-virulence inhibitors and presents screening strategies for identifying these compounds.
Collapse
Affiliation(s)
| | | | - Hilario C Mantovani
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
7
|
Olchowik-Grabarek E, Mies F, Sekowski S, Dubis AT, Laurent P, Zamaraeva M, Swiecicka I, Shlyonsky V. Enzymatic synthesis and characterization of aryl iodides of some phenolic acids with enhanced antibacterial properties. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184011. [PMID: 35872033 DOI: 10.1016/j.bbamem.2022.184011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Phenolic acids represent a class of drugs with mild antibacterial properties. We have synthesized iodinated gallic and ferulic acids and together with commercially available iodinated forms of salicylic acids studied their cytotoxicity, bacteriostatic and anti-virulence action. Out of these, iodogallic acid had lowest minimal inhibitory concentration (MIC) against Staphylococcus aureus (MIC = 0.4 mM/118.8 μg/ml). Yet, it had strong effect on erythrocyte membrane lipid ordering and on α-hemolysin secretion by the bacteria at lower non-bacteriostatic and non-cytotoxic concentrations (<0.1 mM). Iodogallic acid formed static complexes with α-hemolysin in solutions (logKb = 4.69 ± 0.07) and inhibited its nano-pore conduction in artificial lipid bilayers (IC50 = 37.9 ± 5.3 μM). These effects of iodogallic acid converged on prevention of hemolysis induced by α-hemolysin (IC50 = 41.5 ± 4.2 μM) and pointed to enhanced and diverse anti-virulence properties of some aryl iodides. The analysis of molecular surface electrostatic charge distribution, molecular hydrophilicity, electronegativity, and dipole moment of studied compounds suggested the importance of the number of hydroxyl groups and their proximity to iodine in anti-virulence activity manifestation. In iodogallic acid, charge redistribution resulted in higher hydrophilicity without concomitant change in overall molecular electronegativity and dipole moment compared to non-iodinated gallic acid. This study shows new directions for the development of antibacterial/antivirulence therapeutics.
Collapse
Affiliation(s)
- Ewa Olchowik-Grabarek
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, Poland
| | - Frédérique Mies
- Laboratory of Physiology and Pharmacology, Faculty of Medicine, Université libre de Bruxelles, Belgium
| | - Szymon Sekowski
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, Poland
| | - Alina T Dubis
- Department of Organic Chemistry, Faculty of Chemistry, University of Bialystok, Poland
| | - Pascal Laurent
- Laboratory of Chemistry Instruction, Faculty of Medicine, Université libre de Bruxelles, Belgium
| | - Maria Zamaraeva
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, Poland
| | - Izabela Swiecicka
- Laboratory of Molecular Biophysics, Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, Poland
| | - Vadim Shlyonsky
- Laboratory of Physiology and Pharmacology, Faculty of Medicine, Université libre de Bruxelles, Belgium.
| |
Collapse
|
8
|
Ulhuq FR, Mariano G. Bacterial pore-forming toxins. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001154. [PMID: 35333704 PMCID: PMC9558359 DOI: 10.1099/mic.0.001154] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/03/2022] [Indexed: 12/11/2022]
Abstract
Pore-forming toxins (PFTs) are widely distributed in both Gram-negative and Gram-positive bacteria. PFTs can act as virulence factors that bacteria utilise in dissemination and host colonisation or, alternatively, they can be employed to compete with rival microbes in polymicrobial niches. PFTs transition from a soluble form to become membrane-embedded by undergoing large conformational changes. Once inserted, they perforate the membrane, causing uncontrolled efflux of ions and/or nutrients and dissipating the protonmotive force (PMF). In some instances, target cells intoxicated by PFTs display additional effects as part of the cellular response to pore formation. Significant progress has been made in the mechanistic description of pore formation for the different PFTs families, but in several cases a complete understanding of pore structure remains lacking. PFTs have evolved recognition mechanisms to bind specific receptors that define their host tropism, although this can be remarkably diverse even within the same family. Here we summarise the salient features of PFTs and highlight where additional research is necessary to fully understand the mechanism of pore formation by members of this diverse group of protein toxins.
Collapse
Affiliation(s)
- Fatima R. Ulhuq
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
9
|
Du X, Wang Y, Zhang S, Fan P, Yan S, Zhang P, Chen HY, Huang S. Microscopic Screening of Cyclodextrin Channel Blockers by DiffusiOptoPhysiology. Anal Chem 2021; 93:14161-14168. [PMID: 34641671 DOI: 10.1021/acs.analchem.1c02775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Blockers of pore-forming toxins (PFTs) limit bacterial virulence by blocking relevant channel proteins. However, screening of desired blockers from a large pool of candidate molecules is not a trivial task. Acknowledging its advantages of low cost, high throughput, and multiplicity, DiffusiOptoPhysiology (DOP), an emerging nanopore technique that visually monitors the states of individual channel proteins without using any electrodes, has shown its potential use in the screening of channel blockers. By taking different α-hemolysin (α-HL) mutants as model PFTs and different cyclodextrins as model blockers, we report direct screening of pore blockers solely by using fluorescence microscopy. Different combinations of pores and blockers were simultaneously evaluated on the same DOP chip and a single-molecule resolution is directly achieved. The entire chip is composed of low-cost and biocompatible materials, which is fully disposable after each use. Though only demonstrated with cyclodextrin derivatives and α-HL mutants, this proof of concept has also suggested its generality to investigate other pore-forming proteins.
Collapse
Affiliation(s)
- Xiaoyu Du
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Yuqin Wang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Shanyu Zhang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Pingping Fan
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Shuanghong Yan
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Panke Zhang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hong-Yuan Chen
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Shuo Huang
- State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| |
Collapse
|
10
|
Ahmad-Mansour N, Loubet P, Pouget C, Dunyach-Remy C, Sotto A, Lavigne JP, Molle V. Staphylococcus aureus Toxins: An Update on Their Pathogenic Properties and Potential Treatments. Toxins (Basel) 2021; 13:677. [PMID: 34678970 PMCID: PMC8540901 DOI: 10.3390/toxins13100677] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 01/12/2023] Open
Abstract
Staphylococcus aureus is a clinically important pathogen that causes a wide range of human infections, from minor skin infections to severe tissue infection and sepsis. S. aureus has a high level of antibiotic resistance and is a common cause of infections in hospitals and the community. The rising prevalence of community-acquired methicillin-resistant S. aureus (CA-MRSA), combined with the important severity of S. aureus infections in general, has resulted in the frequent use of anti-staphylococcal antibiotics, leading to increasing resistance rates. Antibiotic-resistant S. aureus continues to be a major health concern, necessitating the development of novel therapeutic strategies. S. aureus uses a wide range of virulence factors, such as toxins, to develop an infection in the host. Recently, anti-virulence treatments that directly or indirectly neutralize S. aureus toxins have showed promise. In this review, we provide an update on toxin pathogenic characteristics, as well as anti-toxin therapeutical strategies.
Collapse
Affiliation(s)
- Nour Ahmad-Mansour
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
| | - Paul Loubet
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Cassandra Pouget
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, 30908 Nîmes, France;
| | - Catherine Dunyach-Remy
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Albert Sotto
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Jean-Philippe Lavigne
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Virginie Molle
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
| |
Collapse
|
11
|
Sardaru MC, Rosca I, Morariu S, Ursu EL, Ghiarasim R, Rotaru A. Injectable Thixotropic β-Cyclodextrin-Functionalized Hydrogels Based on Guanosine Quartet Assembly. Int J Mol Sci 2021; 22:ijms22179179. [PMID: 34502085 PMCID: PMC8431444 DOI: 10.3390/ijms22179179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/16/2022] Open
Abstract
Facile method for the preparation of β–cyclodextrin–functionalized hydrogels based on guanosine quartet assembly was described. A series of seven hydrogels were prepared by linking β–cyclodextrin molecules with guanosine moieties in different ratios through benzene–1,4–diboronic acid linker in the presence of potassium hydroxide. The potassium ions acted as a reticulation agent by forming guanosine quartets, leading to the formation of self–sustained transparent hydrogels. The ratios of the β–cyclodextrin and guanosine components have a significant effect on the internal structuration of the components and, correspondingly, on the mechanical properties of the final gels, offering a tunablity of the system by varying the components ratio. The insights into the hydrogels’ structuration were achieved by circular dichroism, scanning electron microscopy, atomic force microscopy, and X–ray diffraction. Rheological measurements revealed self–healing and thixotropic properties of all the investigated samples, which, in combination with available cyclodextrin cavities for active components loading, make them remarkable candidates for specific applications in biomedical and pharmaceutical fields. Moreover, all the prepared samples displayed selective antimicrobial properties against S. aureus in planktonic and biofilm phase, the activity also depending on the guanosine and cyclodextrin ratio within the hydrogel structure.
Collapse
Affiliation(s)
- Monica-Cornelia Sardaru
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania; (M.-C.S.); (I.R.); (E.-L.U.); (R.G.)
| | - Irina Rosca
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania; (M.-C.S.); (I.R.); (E.-L.U.); (R.G.)
| | - Simona Morariu
- Natural Polymers, Bioactive and Biocompatible Materials, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania;
| | - Elena-Laura Ursu
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania; (M.-C.S.); (I.R.); (E.-L.U.); (R.G.)
| | - Razvan Ghiarasim
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania; (M.-C.S.); (I.R.); (E.-L.U.); (R.G.)
| | - Alexandru Rotaru
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, Romanian Academy, Grigore Ghica Voda Alley 41 A, Iasi 700487, Romania; (M.-C.S.); (I.R.); (E.-L.U.); (R.G.)
- Correspondence:
| |
Collapse
|
12
|
Liu W, Nestorovich EM. Anthrax toxin channel: What we know based on over 30 years of research. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183715. [PMID: 34332985 DOI: 10.1016/j.bbamem.2021.183715] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 07/21/2021] [Accepted: 07/24/2021] [Indexed: 10/20/2022]
Abstract
Protective antigen channel is the central component of the deadly anthrax exotoxin responsible for binding and delivery of the toxin's enzymatic lethal and edema factor components into the cytosol. The channel, which is more than three times longer than the lipid bilayer membrane thickness and has a 6-Å limiting diameter, is believed to provide a sophisticated unfoldase and translocase machinery for the foreign protein transport into the host cell cytosol. The tripartite toxin can be reengineered, one component at a time or collectively, to adapt it for the targeted cancer therapeutic treatments. In this review, we focus on the biophysical studies of the protective antigen channel-forming activity, small ion transport properties, enzymatic factor translocation, and blockage comparing it with the related clostridial binary toxin channels. We address issues linked to the anthrax toxin channel structural dynamics and lipid dependence, which are yet to become generally recognized as parts of the toxin translocation machinery.
Collapse
Affiliation(s)
- Wenxing Liu
- Department of Biology, The Catholic University of America, 620 Michigan Ave, Washington, DC 20064, USA
| | - Ekaterina M Nestorovich
- Department of Biology, The Catholic University of America, 620 Michigan Ave, Washington, DC 20064, USA.
| |
Collapse
|
13
|
Vlaeminck J, Raafat D, Surmann K, Timbermont L, Normann N, Sellman B, van Wamel WJB, Malhotra-Kumar S. Exploring Virulence Factors and Alternative Therapies against Staphylococcus aureus Pneumonia. Toxins (Basel) 2020; 12:toxins12110721. [PMID: 33218049 PMCID: PMC7698915 DOI: 10.3390/toxins12110721] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/13/2022] Open
Abstract
Pneumonia is an acute pulmonary infection associated with high mortality and an immense financial burden on healthcare systems. Staphylococcus aureus is an opportunistic pathogen capable of inducing S. aureus pneumonia (SAP), with some lineages also showing multidrug resistance. Given the high level of antibiotic resistance, much research has been focused on targeting S. aureus virulence factors, including toxins and biofilm-associated proteins, in an attempt to develop effective SAP therapeutics. Despite several promising leads, many hurdles still remain for S. aureus vaccine research. Here, we review the state-of-the-art SAP therapeutics, highlight their pitfalls, and discuss alternative approaches of potential significance and future perspectives.
Collapse
Affiliation(s)
- Jelle Vlaeminck
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
| | - Dina Raafat
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, 17475 Greifswald, Germany; (D.R.); (N.N.)
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt
| | - Kristin Surmann
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany;
| | - Leen Timbermont
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
| | - Nicole Normann
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, 17475 Greifswald, Germany; (D.R.); (N.N.)
| | - Bret Sellman
- Microbiome Discovery, Microbial Sciences, BioPharmaceuticals R & D, AstraZeneca, Gaithersburg, MD 20878, USA;
| | - Willem J. B. van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 Rotterdam, The Netherlands;
| | - Surbhi Malhotra-Kumar
- Laboratory of Medical Microbiology, Vaccine and Infectious Diseases Institute, University of Antwerp, 2610 Antwerp, Belgium; (J.V.); (L.T.)
- Correspondence: ; Tel.: +32-3-265-27-52
| |
Collapse
|
14
|
Inhibition of interaction between Staphylococcus aureus α-hemolysin and erythrocytes membrane by hydrolysable tannins: structure-related activity study. Sci Rep 2020; 10:11168. [PMID: 32636484 PMCID: PMC7341856 DOI: 10.1038/s41598-020-68030-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/11/2020] [Indexed: 01/17/2023] Open
Abstract
The objective of the study was a comparative analysis of the antihemolytic activity against two Staphylococcus aureus strains (8325-4 and NCTC 5655) as well as α-hemolysin and of the membrane modifying action of four hydrolysable tannins with different molecular mass and flexibility: 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-d-glucose (T1), 1,2,3,4,5-penta-O-galloyl-β-d-glucose (T2), 3-O-galloyl-1,2-valoneoyl-β-d-glucose (T3) and 1,2-di-O-galloyl-4,6-valoneoyl-β-d-glucose (T4). We showed that all the compounds studied manifested antihemolytic effects in the range of 5–50 µM concentrations. However, the degree of the reduction of hemolysis by the investigated tannins was not uniform. A valoneoyl group—containing compounds (T3 and T4) were less active. Inhibition of the hemolysis induced by α-hemolysin was also noticed on preincubated with the tannins and subsequently washed erythrocytes. In this case the efficiency again depended on the tannin structure and could be represented by the following order: T1 > T2 > T4 > T3. We also found a relationship between the degree of antihemolytic activity of the tannins studied and their capacity to increase the ordering parameter of the erythrocyte membrane outer layer and to change zeta potential. Overall, our study showed a potential of the T1 and T2 tannins as anti-virulence agents. The results of this study using tannins with different combinations of molecular mass and flexibility shed additional light on the role of tannin structure in activity manifestation.
Collapse
|
15
|
Polyketides from marine-derived Aspergillus welwitschiae inhibit Staphylococcus aureus virulence factors and potentiate vancomycin antibacterial activity in vivo. Microb Pathog 2020; 143:104066. [DOI: 10.1016/j.micpath.2020.104066] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/09/2020] [Accepted: 02/12/2020] [Indexed: 12/11/2022]
|
16
|
Liu JY, Zhang X, Tian BR. Selective modifications at the different positions of cyclodextrins: a review of strategies. Turk J Chem 2020; 44:261-278. [PMID: 33488156 PMCID: PMC7671212 DOI: 10.3906/kim-1910-43] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/21/2020] [Indexed: 12/19/2022] Open
Abstract
Cyclodextrins (CDs) are natural, nontoxic, and biodegradable macrocyclic oligosaccharides. As supramolecular hosts, CDs have numerous applications in many aspects. However, nonsubstituted CDs have the disadvantages of solubility, unspecific recognition sites, and weak interactions with guest molecules. Therefore, new CD-based derivatives are successfully designed, synthesized, and widely used in various fields. This contribution outlines the research progress in CD derivatives. In particular, this review emphasizes the synthesis and application of CDs modified through functionalization in definite positions, random substitution, and reconstruction of the skeleton. At the end of this review, a summary and future directions are presented.
Collapse
Affiliation(s)
- Jia Yue Liu
- School of Pharmacy, Ningxia Medical University, Yinchuan P.R. China
| | - Xiao Zhang
- Pingliang Center for Disease Control and Prevention, Pingliang P.R. China
| | - Bing Ren Tian
- School of Pharmacy, Ningxia Medical University, Yinchuan P.R. China.,College of Chemistry and Chemical Engineering, Xinjiang University, Urumchi P.R. China
| |
Collapse
|
17
|
Marchetti M, De Bei O, Bettati S, Campanini B, Kovachka S, Gianquinto E, Spyrakis F, Ronda L. Iron Metabolism at the Interface between Host and Pathogen: From Nutritional Immunity to Antibacterial Development. Int J Mol Sci 2020; 21:E2145. [PMID: 32245010 PMCID: PMC7139808 DOI: 10.3390/ijms21062145] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/08/2023] Open
Abstract
Nutritional immunity is a form of innate immunity widespread in both vertebrates and invertebrates. The term refers to a rich repertoire of mechanisms set up by the host to inhibit bacterial proliferation by sequestering trace minerals (mainly iron, but also zinc and manganese). This strategy, selected by evolution, represents an effective front-line defense against pathogens and has thus inspired the exploitation of iron restriction in the development of innovative antimicrobials or enhancers of antimicrobial therapy. This review focuses on the mechanisms of nutritional immunity, the strategies adopted by opportunistic human pathogen Staphylococcus aureus to circumvent it, and the impact of deletion mutants on the fitness, infectivity, and persistence inside the host. This information finally converges in an overview of the current development of inhibitors targeting the different stages of iron uptake, an as-yet unexploited target in the field of antistaphylococcal drug discovery.
Collapse
Affiliation(s)
- Marialaura Marchetti
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
| | - Omar De Bei
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Stefano Bettati
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
- National Institute of Biostructures and Biosystems, 00136 Rome, Italy
| | - Barbara Campanini
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Sandra Kovachka
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Eleonora Gianquinto
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Luca Ronda
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
| |
Collapse
|
18
|
Caira MR. Cyclodextrin Inclusion of Medicinal Compounds for Enhancement of their Physicochemical and Biopharmaceutical Properties. Curr Top Med Chem 2019; 19:2357-2370. [PMID: 31648636 DOI: 10.2174/1568026619666191018101524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 08/07/2019] [Accepted: 08/26/2019] [Indexed: 12/18/2022]
Abstract
Owing to their wide structural diversity and unique complexing properties, cyclodextrins (CDs) find manifold applications in drug discovery and development. The focus of this mini-review is on their uses as 'enabling excipients' both in the context of early drug discovery and in subsequent optimisation of drug performance. Features highlighted here include descriptions of the structures of CDs, synthetic derivatisation to fine-tune their properties, the nature of inclusion complexation of drugs within the CD cavity, methodology for the study of free and complexed hosts in the solid state and in solution, the inherent pharmacological activity of several CDs and its utility, novel CD-based drug delivery systems, and the role of CDs in drug discovery and optimisation. Illustrative examples are generally based on research reported during the last two decades. Application of CDs to the optimisation of the performance of established drugs is commonplace, but there are many opportunities for the intervention of CDs during the early stages of drug discovery, which could guide the selection of suitable candidates for development, thereby contributing to reducing the attrition rate of new molecular entities.
Collapse
Affiliation(s)
- Mino R Caira
- Department of Chemistry, Centre for Supramolecular Chemistry Research, University of Cape Town, Rondebosch 7701, South Africa
| |
Collapse
|
19
|
Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
Collapse
Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| |
Collapse
|
20
|
Exploring the Nature of Cationic Blocker Recognition by the Anthrax Toxin Channel. Biophys J 2019; 117:1751-1763. [PMID: 31587826 DOI: 10.1016/j.bpj.2019.08.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/11/2019] [Accepted: 08/05/2019] [Indexed: 01/20/2023] Open
Abstract
Obstructing conductive pathways of the channel-forming toxins with targeted blockers is a promising drug design approach. Nearly all tested positively charged ligands have been shown to reversibly block the cation-selective channel-forming protective antigen (PA63) component of the binary anthrax toxin. The cationic ligands with more hydrophobic surfaces, particularly those carrying aromatic moieties, inhibited PA63 more effectively. To understand the physical basis of PA63 selectivity for a particular ligand, detailed information is required on how the blocker structural elements (e.g., positively charged and aromatic groups) influence the molecular kinetics of the blocker/channel binding reactions. In this study, we address this problem using the high-resolution single-channel planar lipid bilayer technique. Several structurally distinct cationic blockers, namely per-6-S-(3-amino) propyl-β-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-α-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-β-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-γ-cyclodextrin, methyltriphenylphosphonium ion, and G0 polyamidoamine dendrimer are tested for their ability to inhibit the heptameric and octameric PA63 variants and PA63F427A mutant. The F427 residues form a hydrophobic constriction region inside the channel, known as the "ϕ-clamp." We show that the cationic blockers interact with PA63 through a combination of forces. Analysis of the binding reaction kinetics suggests the involvement of cation-π, Coulomb, and salt-concentration-independent π-π or hydrophobic interactions in the cationic cyclodextrin binding. It is possible that these blockers bind to the ϕ-clamp and are also stabilized by the Coulomb interactions of their terminal amino groups with the water-exposed negatively charged channel residues. In PA63F427A, only the suggested Coulomb component of the cyclodextrin interaction remains. Methyltriphenylphosphonium ion and G0 polyamidoamine dendrimer, despite being positively charged, interact primarily with the ϕ-clamp. We also show that seven- and eightfold symmetric cyclodextrins effectively block the heptameric and octameric forms of PA63 interchangeably, adding flexibility to the earlier formulated blocker/target symmetry match requirement.
Collapse
|
21
|
Staphylococcus aureus Toxins: From Their Pathogenic Roles to Anti-virulence Therapy Using Natural Products. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-019-0059-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
22
|
Yamini G, Nestorovich EM. Multivalent Inhibitors of Channel-Forming Bacterial Toxins. Curr Top Microbiol Immunol 2019; 406:199-227. [PMID: 27469304 PMCID: PMC6814628 DOI: 10.1007/82_2016_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Rational design of multivalent molecules represents a remarkable modern tool to transform weak non-covalent interactions into strong binding by creating multiple finely-tuned points of contact between multivalent ligands and their supposed multivalent targets. Here, we describe several prominent examples where the multivalent blockers were investigated for their ability to directly obstruct oligomeric channel-forming bacterial exotoxins, such as the pore-forming bacterial toxins and B component of the binary bacterial toxins. We address problems related to the blocker/target symmetry match and nature of the functional groups, as well as chemistry and length of the linkers connecting the functional groups to their multivalent scaffolds. Using the anthrax toxin and AB5 toxin case studies, we briefly review how the oligomeric toxin components can be successfully disabled by the multivalent non-channel-blocking inhibitors, which are based on a variety of multivalent scaffolds.
Collapse
Affiliation(s)
- Goli Yamini
- Department of Biology, The Catholic University of America, Washington, D.C., 20064, USA
| | | |
Collapse
|
23
|
Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote. Nat Commun 2019; 10:1655. [PMID: 31040274 PMCID: PMC6491561 DOI: 10.1038/s41467-019-09681-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 03/25/2019] [Indexed: 01/11/2023] Open
Abstract
The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection of a jellyfish venom-induced cell death pathway by screening for host components required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis. We identify the peripheral membrane protein ATP2B1, a calcium transporting ATPase, as one host factor required for venom cytotoxicity. Targeting ATP2B1 prevents venom action and confers long lasting protection. Informatics analysis of host genes required for venom cytotoxicity reveal pathways not previously implicated in cell death. We also discover a venom antidote that functions up to 15 minutes after exposure and suppresses tissue necrosis and pain in mice. These results highlight the power of whole genome CRISPR screening to investigate venom mechanisms of action and to rapidly identify new medicines. Box jellyfish venom causes tissue damage, pain, and death through unknown molecular mechanisms. Here, Lau et al. perform a CRISPR screen to identify genes required for venom action and use this information to develop an antidote that blocks venom-induced pain and tissue damage in vivo.
Collapse
|
24
|
Affiliation(s)
- Lin-Lin Zhou
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai 201203 China
- University of the Chinese Academy of Sciences; Beijing 100049 China
| | - Cai-Guang Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai 201203 China
| |
Collapse
|
25
|
Pharmacological Targeting of Pore-Forming Toxins as Adjunctive Therapy for Invasive Bacterial Infection. Toxins (Basel) 2018; 10:toxins10120542. [PMID: 30562923 PMCID: PMC6316385 DOI: 10.3390/toxins10120542] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/23/2022] Open
Abstract
For many of the most important human bacterial infections, invasive disease severity is fueled by the cell damaging and pro-inflammatory effects of secreted pore-forming toxins (PFTs). Isogenic PFT-knockout mutants, e.g., Staphylococcus aureus lacking α-toxin or Streptococcus pneumoniae deficient in pneumolysin, show attenuation in animal infection models. This knowledge has inspired multi-model investigations of strategies to neutralize PFTs or counteract their toxicity as a novel pharmacological approach to ameliorate disease pathogenesis in clinical disease. Promising examples of small molecule, antibody or nanotherapeutic drug candidates that directly bind and neutralize PFTs, block their oligomerization or membrane receptor interactions, plug establishment membrane pores, or boost host cell resiliency to withstand PFT action have emerged. The present review highlights these new concepts, with a special focus on β-PFTs produced by leading invasive human Gram-positive bacterial pathogens. Such anti-virulence therapies could be applied as an adjunctive therapy to antibiotic-sensitive and -resistant strains alike, and further could be free of deleterious effects that deplete the normal microflora.
Collapse
|
26
|
Vurgun N, Nitz M. Highly Functionalized β-Cyclodextrins by Solid-Supported Synthesis. Chemistry 2018; 24:4459-4467. [PMID: 29389050 DOI: 10.1002/chem.201800028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Indexed: 12/26/2022]
Abstract
Using covalent capture, a high yielding selective mono-functionalization of heptakis-[6-deoxy-6-(2-aminoethylsulfanyl)]-β-CD with a 5-mercaptopentyl functional group has been achieved. Here, we demonstrate the immobilization of the mono-thiol functionalized β-CD on PEGA resin via a disulfide bond, enabling solid-phase elaboration of the remaining six primary amines. To showcase the potential of this method, the amines were elaborated to tripeptides through standard Fmoc-peptide chemistry. A small library of CD-tripeptide conjugates was generated which, when reduced from the solid support, could be tagged at the released thiol with an environmentally sensitive fluorophore. The resulting library of sensors showed potential for the differential sensing of various bile salts. The described methodology provides a rapid and versatile route to synthesize highly functionalized libraries of CD derivatives that may be tailored towards applications in sensing, catalysis, and multivalent displays.
Collapse
Affiliation(s)
- Nesrin Vurgun
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada
| | - Mark Nitz
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada
| |
Collapse
|
27
|
Bilitewski U, Blodgett JAV, Duhme-Klair AK, Dallavalle S, Laschat S, Routledge A, Schobert R. Chemical and Biological Aspects of Nutritional Immunity-Perspectives for New Anti-Infectives that Target Iron Uptake Systems. Angew Chem Int Ed Engl 2017; 56:14360-14382. [PMID: 28439959 DOI: 10.1002/anie.201701586] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Indexed: 12/22/2022]
Abstract
Upon bacterial infection, one of the defense mechanisms of the host is the withdrawal of essential metal ions, in particular iron, which leads to "nutritional immunity". However, bacteria have evolved strategies to overcome iron starvation, for example, by stealing iron from the host or other bacteria through specific iron chelators with high binding affinity. Fortunately, these complex interactions between the host and pathogen that lead to metal homeostasis provide several opportunities for interception and, thus, allow the development of novel antibacterial compounds. This Review focuses on iron, discusses recent highlights, and gives some future perspectives which are relevant in the fight against antibiotic resistance.
Collapse
Affiliation(s)
- Ursula Bilitewski
- AG Compound Profiling and Screening, Helmholtz Zentrum für Infektionsforschung, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Joshua A V Blodgett
- Department of Biology, Washington University, St. Louis, MO, 63130-4899, USA
| | | | - Sabrina Dallavalle
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, I-20133, Milano, Italy
| | - Sabine Laschat
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 7, 0569, Stuttgart, Germany
| | - Anne Routledge
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Rainer Schobert
- Organische Chemie I, Universität Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| |
Collapse
|
28
|
Bilitewski U, Blodgett JAV, Duhme-Klair AK, Dallavalle S, Laschat S, Routledge A, Schobert R. Chemische und biologische Aspekte von “Nutritional Immunity” - Perspektiven für neue Antiinfektiva mit Fokus auf bakterielle Eisenaufnahmesysteme. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701586] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ursula Bilitewski
- AG Compound Profiling and Screening; Helmholtz-Zentrum für Infektionsforschung; Inhoffenstraße 7 38124 Braunschweig Deutschland
| | | | | | - Sabrina Dallavalle
- Department of Food, Environmental and Nutritional Sciences; Università degli Studi di Milano; I-20133 Milano Italien
| | - Sabine Laschat
- Institut für Organische Chemie; Universität Stuttgart; Pfaffenwaldring 55, 7 0569 Stuttgart Deutschland
| | - Anne Routledge
- Department of Chemistry; University of York, Heslington; York YO10 5DD Großbritannien
| | - Rainer Schobert
- Organische Chemie I; Universität Bayreuth; Universitätsstraße 30 95447 Bayreuth Deutschland
| |
Collapse
|
29
|
Rokitskaya TI, Nazarov PA, Golovin AV, Antonenko YN. Blocking of Single α-Hemolysin Pore by Rhodamine Derivatives. Biophys J 2017; 112:2327-2335. [PMID: 28591605 DOI: 10.1016/j.bpj.2017.04.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/06/2017] [Accepted: 04/25/2017] [Indexed: 11/30/2022] Open
Abstract
Measurements of ion conductance through α-hemolysin pore in a bilayer lipid membrane revealed blocking of the ion channel by a series of rhodamine 19 and rhodamine B esters. The longest dwell closed time of the blocking was observed with rhodamine 19 butyl ester (C4R1), whereas the octyl ester (C8R1) was of poor effect. Voltage asymmetry in the binding kinetics indicated that rhodamine derivatives bound to the stem part of the aqueous pore lumen. The binding frequency was proportional to a quadratic function of rhodamine concentrations, thereby showing that the dominant binding species were rhodamine dimers. Two levels of the pore conductance and two dwell closed times of the pore were found. The dwell closed times lengthened as the voltage increased, suggesting impermeability of the channel for the ligands. Molecular docking analysis revealed two distinct binding sites within the lumen of the stem of the α-hemolysin pore for the C4R1 dimer, but only one binding site for the C8R1 dimer. The blocking of the α-hemolysin nanopore by rhodamines could be utilized in DNA sequencing as additional optical sensing owing to bright fluorescence of rhodamines if used for DNA labeling.
Collapse
Affiliation(s)
- Tatyana I Rokitskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
| | - Pavel A Nazarov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Andrey V Golovin
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
30
|
Seilie ES, Bubeck Wardenburg J. Staphylococcus aureus pore-forming toxins: The interface of pathogen and host complexity. Semin Cell Dev Biol 2017; 72:101-116. [PMID: 28445785 DOI: 10.1016/j.semcdb.2017.04.003] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/22/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022]
Abstract
Staphylococcus aureus is a prominent human pathogen capable of infecting a variety of host species and tissue sites. This versatility stems from the pathogen's ability to secrete diverse host-damaging virulence factors. Among these factors, the S. aureus pore-forming toxins (PFTs) α-toxin and the bicomponent leukocidins, have garnered much attention for their ability to lyse cells at low concentrations and modulate disease severity. Although many of these toxins were discovered nearly a century ago, their host cell specificities have only been elucidated over the past five to six years, starting with the discovery of the eukaryotic receptor for α-toxin and rapidly followed by identification of the leukocidin receptors. The identification of these receptors has revealed the species- and cell type-specificity of toxin binding, and provided insight into non-lytic effects of PFT intoxication that contribute to disease pathogenesis.
Collapse
Affiliation(s)
- E Sachiko Seilie
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, United States; Department of Microbiology, The University of Chicago, Chicago, IL 60637, United States
| | | |
Collapse
|
31
|
Assis LM, Nedeljković M, Dessen A. New strategies for targeting and treatment of multi-drug resistant Staphylococcus aureus. Drug Resist Updat 2017; 31:1-14. [PMID: 28867240 DOI: 10.1016/j.drup.2017.03.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/07/2017] [Accepted: 03/23/2017] [Indexed: 12/17/2022]
Abstract
Staphylococcus aureus is a major cause of bacterial infection in humans, and has been notoriously able to acquire resistance to a variety of antibiotics. An example is methicillin-resistant S. aureus (MRSA), which despite having been initially associated with clinical settings, now is one of the key causative agents of community-acquired infections. Antibiotic resistance in S. aureus involves mechanisms ranging from drug efflux to increased expression or mutation of target proteins, and this has required innovative approaches to develop novel treatment methodologies. This review provides an overview of the major mechanisms of antibiotic resistance developed by S. aureus, and describes the emerging alternatives being sought to circumvent infection and proliferation, including new generations of classic antibiotics, synergistic approaches, antibodies, and targeting of virulence factors.
Collapse
Affiliation(s)
- L Mayrink Assis
- Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, São Paulo, Brazil
| | - M Nedeljković
- Institut de Biologie Structurale (IBS), Univ Grenoble Alpes, CEA, CNRS, Bacterial Pathogenesis Group, 38044 Grenoble, France
| | - A Dessen
- Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, São Paulo, Brazil; Institut de Biologie Structurale (IBS), Univ Grenoble Alpes, CEA, CNRS, Bacterial Pathogenesis Group, 38044 Grenoble, France.
| |
Collapse
|
32
|
Baaske R, Richter M, Möller N, Ziesemer S, Eiffler I, Müller C, Hildebrandt JP. ATP Release from Human Airway Epithelial Cells Exposed to Staphylococcus aureus Alpha-Toxin. Toxins (Basel) 2016; 8:toxins8120365. [PMID: 27929417 PMCID: PMC5198559 DOI: 10.3390/toxins8120365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 11/20/2022] Open
Abstract
Airway epithelial cells reduce cytosolic ATP content in response to treatment with S. aureus alpha-toxin (hemolysin A, Hla). This study was undertaken to investigate whether this is due to attenuated ATP generation or to release of ATP from the cytosol and extracellular ATP degradation by ecto-enzymes. Exposure of cells to rHla did result in mitochondrial calcium uptake and a moderate decline in mitochondrial membrane potential, indicating that ATP regeneration may have been attenuated. In addition, ATP may have left the cells through transmembrane pores formed by the toxin or through endogenous release channels (e.g., pannexins) activated by cellular stress imposed on the cells by toxin exposure. Exposure of cells to an alpha-toxin mutant (H35L), which attaches to the host cell membrane but does not form transmembrane pores, did not induce ATP release from the cells. The Hla-mediated ATP-release was completely blocked by IB201, a cyclodextrin-inhibitor of the alpha-toxin pore, but was not at all affected by inhibitors of pannexin channels. These results indicate that, while exposure of cells to rHla may somewhat reduce ATP production and cellular ATP content, a portion of the remaining ATP is released to the extracellular space and degraded by ecto-enzymes. The release of ATP from the cells may occur directly through the transmembrane pores formed by alpha-toxin.
Collapse
Affiliation(s)
- Romina Baaske
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Mandy Richter
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Nils Möller
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Sabine Ziesemer
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Ina Eiffler
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Christian Müller
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| | - Jan-Peter Hildebrandt
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Felix Hausdorff-Strasse 1, B.10.06, D-17489 Greifswald, Germany.
| |
Collapse
|
33
|
Eiffler I, Behnke J, Ziesemer S, Müller C, Hildebrandt JP. Staphylococcus aureus α-toxin-mediated cation entry depolarizes membrane potential and activates p38 MAP kinase in airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2016; 311:L676-85. [PMID: 27496896 DOI: 10.1152/ajplung.00090.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022] Open
Abstract
Membrane potential (Vm)-, Na(+)-, or Ca(2+)-sensitive fluorescent dyes were used to analyze changes in Vm or intracellular ion concentrations in airway epithelial cells treated with Staphylococcus aureus α-toxin (Hla), a major virulence factor of pathogenic strains of these bacteria. Gramicidin, a channel-forming peptide causing membrane permeability to monovalent cations, a mutated form of Hla, rHla-H35L, which forms oligomers in the plasma membranes of eukaryotic cells but fails to form functional transmembrane pores, or the cyclodextrin-derivative IB201, a blocker of the Hla pore, were used to investigate the permeability of the pore. Na(+) as well as Ca(2+) ions were able to pass the Hla pore and accumulated in the cytosol. The pore-mediated influx of calcium ions was blocked by IB201. Treatment of cells with recombinant Hla resulted in plasma membrane depolarization as well as in increases in the phosphorylation levels of paxillin (signaling pathway mediating disruption of the actin cytoskeleton) and p38 MAP kinase (signaling pathway resulting in defensive actions). p38 MAP kinase phosphorylation, but not paxillin phosphorylation, was elicited by treatment of cells with gramicidin. Although treatment of cells with rHla-H35L resulted in the formation of membrane-associated heptamers, none of these cellular effects were observed in our experiments. This indicates that formation of functional Hla-transmembrane pores is required to induce the cell physiological changes mediated by α-toxin. Specifically, the changes in ion equilibria and plasma membrane potential are important activators of p38 MAP kinase, a signal transduction module involved in host cell defense.
Collapse
Affiliation(s)
- Ina Eiffler
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Greifswald, Germany
| | - Jane Behnke
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Greifswald, Germany
| | - Sabine Ziesemer
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Greifswald, Germany
| | - Christian Müller
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Greifswald, Germany
| | - Jan-Peter Hildebrandt
- Animal Physiology and Biochemistry, Ernst Moritz Arndt-University, Greifswald, Germany
| |
Collapse
|
34
|
Li W, Wen L, Li C, Chen R, Ye Z, Zhao J, Pan J. Contribution of the outer membrane protein OmpW in Escherichia coli to complement resistance from binding to factor H. Microb Pathog 2016; 98:57-62. [PMID: 27364548 DOI: 10.1016/j.micpath.2016.06.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/14/2016] [Accepted: 06/24/2016] [Indexed: 01/20/2023]
Abstract
The serum complement system is essential for innate immune defense against invading pathogenic bacteria. Some of the 8-stranded β-barrel outer membrane proteins confer bacterial resistance to the innate host immunity. We have previously demonstrated that OmpW, also an 8-stranded β-barrel protein that was identified a decade ago, protects bacteria against host phagocytosis. In this study, we investigated the complement resistance of OmpW. Our results indicate that the upregulation of OmpW is associated with increased survival when bacteria are exposed to normal human sera (NHS). Mutant bacteria lacking OmpW in NHS exhibited significantly lower survival rates in comparison to wild-type and ompW complemented bacteria. Furthermore, the bacterial survival significantly decreased in NHS that was supplemented with EGTA-Mg(2+) compared to that in NHS supplemented with EDTA. These results suggest that OmpW confer resistance to alternative complement pathway-mediated killing. Moreover, the binding of OmpW to factor H, a major inhibitor of alternative pathway, was found, indicating that OmpW recruitment of factor H is a mechanism for bacterial evasion of complement attack.
Collapse
Affiliation(s)
- Weiyan Li
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Liangyou Wen
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Chuchu Li
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Ran Chen
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhicang Ye
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jie Zhao
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jianyi Pan
- School of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
| |
Collapse
|
35
|
Silin V, Kasianowicz JJ, Michelman-Ribeiro A, Panchal RG, Bavari S, Robertson JWF. Biochip for the Detection of Bacillus anthracis Lethal Factor and Therapeutic Agents against Anthrax Toxins. MEMBRANES 2016; 6:E36. [PMID: 27348008 PMCID: PMC5041027 DOI: 10.3390/membranes6030036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 01/18/2023]
Abstract
Tethered lipid bilayer membranes (tBLMs) have been used in many applications, including biosensing and membrane protein structure studies. This report describes a biosensor for anthrax toxins that was fabricated through the self-assembly of a tBLM with B. anthracis protective antigen ion channels that are both the recognition element and electrochemical transducer. We characterize the sensor and its properties with electrochemical impedance spectroscopy and surface plasmon resonance. The sensor shows a sensitivity similar to ELISA and can also be used to rapidly screen for molecules that bind to the toxins and potentially inhibit their lethal effects.
Collapse
Affiliation(s)
- Vitalii Silin
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20899, USA.
| | - John J Kasianowicz
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
| | - Ariel Michelman-Ribeiro
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
| | - Rekha G Panchal
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
| | - Sina Bavari
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
| | - Joseph W F Robertson
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.
| |
Collapse
|
36
|
Ouyang P, Chen J, Sun M, Yin Z, Lin J, Fu H, Shu G, He C, Lv C, Deng X, Wang K, Geng Y, Yin L. Imperatorin inhibits the expression of alpha-hemolysin in Staphylococcus aureus strain BAA-1717 (USA300). Antonie van Leeuwenhoek 2016; 109:915-22. [PMID: 27043440 DOI: 10.1007/s10482-016-0690-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/28/2016] [Indexed: 10/22/2022]
Abstract
Both community-associated and hospital-acquired infections with methicillin-resistant Staphylococcus aureus (MRSA) have been increasingly reported around the world in the past 20 years. In 2006, the Centers for Disease Control and Prevention reported that 64 % of MRSA isolates were of the USA300 clonal type in infected patients in USA. The aim of our study was to estimate the in vitro effect of imperatorin on MRSA strain BAA-1717 (USA300). The effects of imperatorin on alpha-hemolysin (Hla) production, when strain BAA-1717 was co-cultured with sub-inhibitory concentrations of imperatorin, were analysed using susceptibility testing, hemolysis assays, western blotting and real-time PCR. Live/Dead analysis and cytotoxicity assays were employed to examine the protective effect of imperatorin against the strain BAA-1717-mediated injury of human alveolar epithelial cells (A549). The results showed that imperatorin has no anti-S. aureus activity at the tested concentrations in vitro. However, imperatorin can observably inhibit the production of Hla in culture supernatants and reduce the transcriptional levels of hla (the gene encoding Hla) and arg (the accessory gene regulator). Imperatorin prevented Hla-mediated A549 epithelial cell injury in a co-culture system. In conclusion, our results suggested that imperatorin has the potential to be developed as a new anti-virulence drug candidate for managing S. aureus infection.
Collapse
Affiliation(s)
- Ping Ouyang
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Junjie Chen
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Mao Sun
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Zhongqiong Yin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Juchun Lin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Hualin Fu
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Gang Shu
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Changliang He
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Cheng Lv
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Xuming Deng
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Kaiyu Wang
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Yi Geng
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China
| | - Lizi Yin
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, China.
| |
Collapse
|
37
|
Kong C, Neoh HM, Nathan S. Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy. Toxins (Basel) 2016; 8:toxins8030072. [PMID: 26999200 PMCID: PMC4810217 DOI: 10.3390/toxins8030072] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/03/2016] [Accepted: 03/10/2016] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.
Collapse
Affiliation(s)
- Cin Kong
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
| | - Hui-min Neoh
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, 56000 Cheras, Kuala Lumpur, Malaysia.
| | - Sheila Nathan
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
| |
Collapse
|
38
|
Melo MCA, Teixeira LR, Pol-Fachin L, Rodrigues CG. Inhibition of the hemolytic activity caused by Staphylococcus aureus alpha-hemolysin through isatin-Schiff copper(II) complexes. FEMS Microbiol Lett 2015; 363:fnv207. [PMID: 26519261 DOI: 10.1093/femsle/fnv207] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2015] [Indexed: 02/01/2023] Open
Abstract
A great number of pathogens secrete pore-forming proteins during infection. Such molecules, from either bacterial or viral origin, are considered important virulence factors, which makes them attractive targets in the study of new therapeutic agents. Thus, the inhibitory activity of isatin-Schiff base copper(II) complexes was evaluated against membrane damage activity of Staphylococcus aureus α-hemolysin (α-HL). For this purpose, a standard hemolysis assay with rabbit erythrocytes and micromolar concentrations of the compounds was employed. Additionally, planar artificial lipid membranes with a single α-HL ion channel and molecular docking studies were used to elucidate the molecular mechanism of the complexes. Accordingly, the compounds were observed to possess a significant anti-hemolytic activity, capable of interacting with the constriction region of α-HL channel and blocking it in a potential dependent manner. Based on these results, it is expected that such isatin-Schiff base Copper(II) complexes may be employed as cotherapeutic agents for the treatment of staphylococcal infections.
Collapse
Affiliation(s)
- Maria C A Melo
- Laboratory of Membrane Biophysics and Stem Cell Dr. Oleg Krasilnikov, Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Luciana R Teixeira
- Laboratory of Membrane Biophysics and Stem Cell Dr. Oleg Krasilnikov, Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Laercio Pol-Fachin
- Biomaterials Laboratory, Department of Fundamental Chemistry, Federal University of Pernambuco, Recife, Pernambuco, Brazil Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Recife, Pernambuco, Brazil
| | - Claudio G Rodrigues
- Laboratory of Membrane Biophysics and Stem Cell Dr. Oleg Krasilnikov, Department of Biophysics and Radiobiology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| |
Collapse
|
39
|
Sri Charan Bindu B, Mishra DP, Narayan B. Inhibition of virulence of Staphylococcus aureus – a food borne pathogen – by squalene, a functional lipid. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.07.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
40
|
Modifiers of membrane dipole potentials as tools for investigating ion channel formation and functioning. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 315:245-97. [PMID: 25708465 DOI: 10.1016/bs.ircmb.2014.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrostatic fields generated on and within biological membranes play a fundamental role in key processes in cell functions. The role of the membrane dipole potential is of particular interest because of its powerful impact on membrane permeability and lipid-protein interactions, including protein insertion, oligomerization, and function. The membrane dipole potential is defined by the orientation of electric dipoles of lipid headgroups, fatty acid carbonyl groups, and membrane-adsorbed water. As a result, the membrane interior is several hundred millivolts more positive than the external aqueous phase. This potential decrease depends on the lipid, and especially sterol, composition of the membrane. The adsorption of certain electroneutral molecules known as dipole modifiers may also lead to significant changes in the magnitude of the potential decrease. These agents are widely used to study the effects of the dipole potential on membrane transport. This review presents a critical analysis of a variety of data from studies dedicated to ion channel formation and functioning in membranes with different dipole potentials. The types of ion channels found in cellular membranes and pores formed by antimicrobial agents and toxins in artificial lipid membranes are summarized. The mechanisms underlying the influence of the membrane dipole potential on ion channel activity, including dipole-dipole and charge-dipole interactions in the pores and in membranes, are discussed. A hypothesis, in which lipid rafts in both model and cellular membranes also modulate ion channel activity by virtue of an increased or decreased dipole potential, is also considered.
Collapse
|
41
|
Oscherwitz J, Cease KB. Identification and validation of a linear protective neutralizing epitope in the β-pore domain of alpha toxin. PLoS One 2015; 10:e0116882. [PMID: 25635901 PMCID: PMC4311967 DOI: 10.1371/journal.pone.0116882] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 12/16/2014] [Indexed: 02/07/2023] Open
Abstract
The plethora of virulence factors associated with Staphylococcus aureus make this bacterium an attractive candidate for a molecularly-designed epitope-focused vaccine. This approach, which necessitates the identification of neutralizing epitopes for incorporation into a vaccine construct, is being evaluated for pathogens where conventional approaches have failed to elicit protective humoral responses, like HIV-1 and malaria, but may also hold promise for pathogens like S. aureus, where the elicitation of humoral immunity against multiple virulence factors may be required for development of an effective vaccine. Among the virulence factors employed by S. aureus, animal model and epidemiological data suggest that alpha toxin, a multimeric β-pore forming toxin like protective antigen from Bacillus anthracis, is particularly critical, yet no candidate neutralizing epitopes have been delineated in alpha toxin to date. We have previously shown that a linear determinant in the 2β2-2β3 loop of the pore forming domain of B. anthracis protective antigen is a linear neutralizing epitope. Antibody against this site is highly potent for neutralizing anthrax lethal toxin in vitro and for protection of rabbits in vivo from virulent B. anthracis. We hypothesized that sequences in the β-pore of S. aureus alpha toxin that share structural and functional homology to β-pore sequences in protective antigen would contain a similarly critical neutralizing epitope. Using an in vivo mapping strategy employing peptide immunogens, an optimized in vitro toxin neutralization assay, and an in vivo dermonecrosis model, we have now confirmed the presence of this epitope in alpha toxin, termed the pore neutralizing determinant. Antibody specific for this determinant neutralizes alpha toxin in vitro, and is highly effective for mitigating dermonecrosis and bacterial growth in a mouse model of S. aureus USA300 skin infection. The delineation of this linear neutralizing determinant in alpha toxin could facilitate the development of an epitope-focused vaccine against S. aureus.
Collapse
Affiliation(s)
- Jon Oscherwitz
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America; VA Ann Arbor Healthcare System, 2215 Fuller Road, Ann Arbor, Michigan, 48105, United States of America
| | - Kemp B Cease
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America; VA Ann Arbor Healthcare System, 2215 Fuller Road, Ann Arbor, Michigan, 48105, United States of America
| |
Collapse
|
42
|
Arana AM, Bierdeman MA, Balzli CL, Tang A, Caballero AR, Patel R, O'Callaghan RJ. Staphylococcus Alpha-Toxin Action on the Rabbit Iris: Toxic Effects and Their Inhibition. Curr Eye Res 2014; 40:830-8. [DOI: 10.3109/02713683.2014.959609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
43
|
He XP, Li RH, Maisonneuve S, Ruan Y, Chen GR, Xie J. Fluorogenic supramolecular complexes formed between pyrenyl-β-cyclodextrin and glyco-rhodamine for the selective detection of lectins. Chem Commun (Camb) 2014; 50:14141-4. [DOI: 10.1039/c4cc06356b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
44
|
Gurnev PA, Nestorovich EM. Channel-forming bacterial toxins in biosensing and macromolecule delivery. Toxins (Basel) 2014; 6:2483-540. [PMID: 25153255 PMCID: PMC4147595 DOI: 10.3390/toxins6082483] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/08/2014] [Accepted: 08/08/2014] [Indexed: 12/19/2022] Open
Abstract
To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on "Intracellular Traffic and Transport of Bacterial Protein Toxins", reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their "second life" in a variety of developing medical and technological applications.
Collapse
Affiliation(s)
- Philip A Gurnev
- Physics Department, University of Massachusetts, Amherst, MA 01003, USA.
| | | |
Collapse
|
45
|
Roeder M, Nestorovich EM, Karginov VA, Schwan C, Aktories K, Barth H. Tailored cyclodextrin pore blocker protects mammalian cells from clostridium difficile binary toxin CDT. Toxins (Basel) 2014; 6:2097-114. [PMID: 25029374 PMCID: PMC4113744 DOI: 10.3390/toxins6072097] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 06/16/2014] [Accepted: 06/27/2014] [Indexed: 12/11/2022] Open
Abstract
Some Clostridium difficile strains produce, in addition to toxins A and B, the binary toxin Clostridium difficile transferase (CDT), which ADP-ribosylates actin and may contribute to the hypervirulence of these strains. The separate binding and translocation component CDTb mediates transport of the enzyme component CDTa into mammalian target cells. CDTb binds to its receptor on the cell surface, CDTa assembles and CDTb/CDTa complexes are internalised. In acidic endosomes, CDTb mediates the delivery of CDTa into the cytosol, most likely by forming a translocation pore in endosomal membranes. We demonstrate that a seven-fold symmetrical positively charged β-cyclodextrin derivative, per-6-S-(3-aminomethyl)benzylthio-β-cyclodextrin, which was developed earlier as a potent inhibitor of the translocation pores of related binary toxins of Bacillus anthracis, Clostridium botulinum and Clostridium perfringens, protects cells from intoxication with CDT. The pore blocker did not interfere with the CDTa-catalyzed ADP-ribosylation of actin or toxin binding to Vero cells but inhibited the pH-dependent membrane translocation of CDTa into the cytosol. In conclusion, the cationic β-cyclodextrin could serve as the lead compound in a development of novel pharmacological strategies against the CDT-producing strains of C. difficile.
Collapse
Affiliation(s)
- Maurice Roeder
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | | | - Vladimir A Karginov
- Innovative Biologics, Inc., 13455 Sunrise Valley Dr., Suite 200, Herndon, VA 20171, USA.
| | - Carsten Schwan
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79104 Freiburg, Germany.
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79104 Freiburg, Germany.
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| |
Collapse
|
46
|
Förstner P, Bayer F, Kalu N, Felsen S, Förtsch C, Aloufi A, Ng DYW, Weil T, Nestorovich EM, Barth H. Cationic PAMAM dendrimers as pore-blocking binary toxin inhibitors. Biomacromolecules 2014; 15:2461-74. [PMID: 24954629 PMCID: PMC4215879 DOI: 10.1021/bm500328v] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dendrimers are unique highly branched macromolecules with numerous groundbreaking biomedical applications under development. Here we identified poly(amido amine) (PAMAM) dendrimers as novel blockers for the pore-forming B components of the binary anthrax toxin (PA63) and Clostridium botulinum C2 toxin (C2IIa). These pores are essential for delivery of the enzymatic A components of the internalized toxins from endosomes into the cytosol of target cells. We demonstrate that at low μM concentrations cationic PAMAM dendrimers block PA63 and C2IIa to inhibit channel-mediated transport of the A components, thereby protecting HeLa and Vero cells from intoxication. By channel reconstitution and high-resolution current recording, we show that the PAMAM dendrimers obstruct transmembrane PA63 and C2IIa pores in planar lipid bilayers at nM concentrations. These findings suggest a new potential role for the PAMAM dendrimers as effective polyvalent channel-blocking inhibitors, which can protect human target cells from intoxication with binary toxins from pathogenic bacteria.
Collapse
Affiliation(s)
- Philip Förstner
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center , D-89081 Ulm, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Kusters I, van Oijen AM, Driessen AJM. Membrane-on-a-chip: microstructured silicon/silicon-dioxide chips for high-throughput screening of membrane transport and viral membrane fusion. ACS NANO 2014; 8:3380-92. [PMID: 24601516 DOI: 10.1021/nn405884a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Screening of transport processes across biological membranes is hindered by the challenge to establish fragile supported lipid bilayers and the difficulty to determine at which side of the membrane reactants reside. Here, we present a method for the generation of suspended lipid bilayers with physiological relevant lipid compositions on microstructured Si/SiO2 chips that allow for high-throughput screening of both membrane transport and viral membrane fusion. Simultaneous observation of hundreds of single-membrane channels yields statistical information revealing population heterogeneities of the pore assembly and conductance of the bacterial toxin α-hemolysin (αHL). The influence of lipid composition and ionic strength on αHL pore formation was investigated at the single-channel level, resolving features of the pore-assembly pathway. Pore formation is inhibited by a specific antibody, demonstrating the applicability of the platform for drug screening of bacterial toxins and cell-penetrating agents. Furthermore, fusion of H3N2 influenza viruses with suspended lipid bilayers can be observed directly using a specialized chip architecture. The presented micropore arrays are compatible with fluorescence readout from below using an air objective, thus allowing high-throughput screening of membrane transport in multiwell formats in analogy to plate readers.
Collapse
Affiliation(s)
- Ilja Kusters
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and the Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 7, Groningen, The Netherlands
| | | | | |
Collapse
|
48
|
Ukhatskaya EV, Kurkov SV, Hjálmarsdóttir MA, Karginov VA, Matthews SE, Rodik RV, Kalchenko VI, Loftsson T. Cationic quaternized aminocalix[4]arenes: cytotoxicity, haemolytic and antibacterial activities. Int J Pharm 2013; 458:25-30. [PMID: 24157345 DOI: 10.1016/j.ijpharm.2013.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/08/2013] [Accepted: 10/13/2013] [Indexed: 10/26/2022]
Abstract
This study reports the characterization of three cationic amphiphillic aminocalix[4]arenes as potential antimicrobial agents in vitro. In cytotoxicity tests on mouse macrophage RAW 264.7 cells aminocalix[4]arenes 1 and 3 showed no toxicity up to 200 and 100 μM concentrations, respectively, while 2 was non-toxic only up to 50 μM. With regard to the haemolytic activity on rabbit red blood cells, 1 was not active at concentrations up to 100 μM in contrast to the other two studied macrocycles. Compounds showed negligible ability to protect either mouse macrophage RAW 264.7 cells from anthrax lethal toxin of Bacillus anthracis (B. anthracis) or rabbit red blood cells from α-haemolysin of Staphylococcus aureus (S. aureus) in comparison to amino-β-cyclodextrins. However, all aminocalix[4]arenes showed potential as antimicrobials. Their minimum inhibitory concentrations (MIC) against Escherichia coli (E. coli) and S. aureus were in the 16-32 μg/ml concentration range, while minimum lethal concentrations (MLC) varied from 16 to 256 μg/ml depending on the bacteria and aminocalix[4]arene considered. Macrocycle 1 showed partial synergism against S. aureus in tandem with a model antibacterial drug, fusidic acid, at certain concentration combinations.
Collapse
Affiliation(s)
- Elena V Ukhatskaya
- Faculty of Pharmaceutical Sciences, University of Iceland, Hofsvallagata 53, IS-107, Reykjavik, Iceland
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Cyclodextrin derivatives as anti-infectives. Curr Opin Pharmacol 2013; 13:717-25. [PMID: 24011515 DOI: 10.1016/j.coph.2013.08.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/05/2013] [Accepted: 08/14/2013] [Indexed: 11/22/2022]
Abstract
Cyclodextrin derivatives can be utilized as anti-infectives with pore-forming proteins as the targets. The highly efficient selection of potent inhibitors was achieved because per-substituted cyclodextrins have the same symmetry as the target pores. Inhibitors of several bacterial toxins produced by Bacillus anthracis, Staphylococcus aureus, Clostridium perfringens, Clostridium botulinum, and Clostridium difficile were identified from a library of ∼200 CD derivatives. It was demonstrated that multi-targeted inhibitors can be found using this approach and could be utilized for the development of broad-spectrum drugs against various pathogens.
Collapse
|
50
|
Beitzinger C, Bronnhuber A, Duscha K, Riedl Z, Huber-Lang M, Benz R, Hajós G, Barth H. Designed azolopyridinium salts block protective antigen pores in vitro and protect cells from anthrax toxin. PLoS One 2013; 8:e66099. [PMID: 23840407 PMCID: PMC3688708 DOI: 10.1371/journal.pone.0066099] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/02/2013] [Indexed: 11/28/2022] Open
Abstract
Background Several intracellular acting bacterial protein toxins of the AB-type, which are known to enter cells by endocytosis, are shown to produce channels. This holds true for protective antigen (PA), the binding component of the tripartite anthrax-toxin of Bacillus anthracis. Evidence has been presented that translocation of the enzymatic components of anthrax-toxin across the endosomal membrane of target cells and channel formation by the heptameric/octameric PA63 binding/translocation component are related phenomena. Chloroquine and some 4-aminoquinolones, known as potent drugs against Plasmodium falciparium infection of humans, block efficiently the PA63-channel in a dose dependent way. Methodology/Principal Findings Here we demonstrate that related positively charged heterocyclic azolopyridinium salts block the PA63-channel in the µM range, when both, inhibitor and PA63 are added to the same side of the membrane, the cis-side, which corresponds to the lumen of acidified endosomal vesicles of target cells. Noise-analysis allowed the study of the kinetics of the plug formation by the heterocycles. In vivo experiments using J774A.1 macrophages demonstrated that the inhibitors of PA63-channel function also efficiently block intoxication of the cells by the combination lethal factor and PA63 in the same concentration range as they block the channels in vitro. Conclusions/Significance These results strongly argue in favor of a transport of lethal factor through the PA63-channel and suggest that the heterocycles used in this study could represent attractive candidates for development of novel therapeutic strategies against anthrax.
Collapse
Affiliation(s)
- Christoph Beitzinger
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Anika Bronnhuber
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Kerstin Duscha
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Zsuzsanna Riedl
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Markus Huber-Lang
- Institute of Traumatology, Hand- and Reconstructive Surgery, University of Ulm Medical Center, Ulm, Germany
| | - Roland Benz
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
- * E-mail: (RB); (HB)
| | - György Hajós
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
- * E-mail: (RB); (HB)
| |
Collapse
|