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Hansen AM, Bonke G, Hogendorf WFJ, Björkling F, Nielsen J, Kongstad KT, Zabicka D, Tomczak M, Urbas M, Nielsen PE, Franzyk H. Microwave-assisted solid-phase synthesis of antisense acpP peptide nucleic acid-peptide conjugates active against colistin- and tigecycline-resistant E. coli and K. pneumoniae. Eur J Med Chem 2019; 168:134-145. [PMID: 30807888 DOI: 10.1016/j.ejmech.2019.02.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 11/26/2022]
Abstract
Recent discovery of potent antibacterial antisense PNA-peptide conjugates encouraged development of a fast and efficient synthesis protocol that facilitates structure-activity studies. The use of an Fmoc/Boc protection scheme for both PNA monomers and amino acid building blocks in combination with microwave-assisted solid-phase synthesis proved to be a convenient procedure for continuous assembly of antisense PNA-peptide conjugates. A validated antisense PNA oligomer (CTCATACTCT; targeting mRNA of the acpP gene) was linked to N-terminally modified drosocin (i.e., RXR-PRPYSPRPTSHPRPIRV; X = aminohexanoic acid) or to a truncated Pip1 peptide (i.e., RXRRXR-IKILFQNRRMKWKK; X = aminohexanoic acid), and determination of the antibacterial effects of the resulting conjugates allowed assessment of the influence of different linkers as well as differences between the L- and D-forms of the peptides. The drosocin-derived compound without a linker moiety exhibited highest antibacterial activity against both wild-type Escherichia coli and Klebsiella pneumoniae (MICs in the range 2-4 μg/mL ∼ 0.3-0.7 μM), while analogues displaying an ethylene glycol (eg1) moiety or a polar maleimide linker also possessed activity toward wild-type K. pneumoniae (MICs of 4-8 μg/mL ∼ 0.6-1.3 μM). Against two colistin-resistant E. coli strains the linker-deficient compound proved most potent (with MICs in the range 2-4 μg/mL ∼ 0.3-0.7 μM). The truncated all-L Pip1 peptide had moderate inherent activity against E. coli, and this was unaltered or reduced upon conjugation to the antisense PNA oligomer. By contrast, this peptide was 8-fold less potent against K. pneumoniae, but in this case some PNA-peptide conjugates exhibited potent antisense activity (MICs of 2-8 μg/mL ∼ 0.3-1.2 μM). Most interestingly, the antibacterial activity of the D-form peptide itself was 2- to 16-fold higher than that of the L-form, even for the colistin- and tigecycline-resistant E. coli strains (MIC of 1-2 μg/mL ∼ 0.25-0.5 μM). Low activity was found for conjugates with a two-mismatch PNA sequence corroborating an antisense mode of action. Conjugates containing a D-form peptide were also significantly less active. In conclusion, we have designed and synthesized antisense PNA-drosocin conjugates with potent antibacterial activity against colistin- and tigecycline-resistant E. coli and K. pneumonia without concomitant hemolytic properties. In addition, a truncated D-form of Pip1 was identified as a peptide exhibiting potent activity against both wild-type and multidrug-resistant E. coli, P. aeruginosa, and A. baumannii (MICs within the range 1-4 μg/mL ∼ 0.25-1 μM) as well as toward wild-type Staphylococcus aureus (MIC of 2-4 μg/mL ∼ 0.5-1.0 μM).
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Affiliation(s)
- Anna Mette Hansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - Gitte Bonke
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - Wouter Frederik Johan Hogendorf
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - Fredrik Björkling
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - John Nielsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - Kenneth T Kongstad
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark
| | - Dorota Zabicka
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, ul. Chełmska 30/34, 00-725, Warsaw, Poland
| | - Magdalena Tomczak
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, ul. Chełmska 30/34, 00-725, Warsaw, Poland
| | - Malgorzata Urbas
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, ul. Chełmska 30/34, 00-725, Warsaw, Poland
| | - Peter E Nielsen
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2100, Denmark
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 162, DK-2100, Denmark.
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102
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Giedyk M, Jackowska A, Równicki M, Kolanowska M, Trylska J, Gryko D. Vitamin B 12 transports modified RNA into E. coli and S. Typhimurium cells. Chem Commun (Camb) 2019; 55:763-766. [PMID: 30480264 DOI: 10.1039/c8cc05064c] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Specifically designed, antisense oligonucleotides are promising candidates for antibacterial drugs. They suppress the correct expression of bacterial genes by complementary binding to essential sequences of bacterial DNA or RNA. The main obstacle in fully utilizing their potential as therapeutic agents comes from the fact that bacteria do not uptake oligonucleotides from their environment. Herein, we report that vitamin B12 can transport oligonucleotides into Escherichia coli and Salmonella typhimurium cells. 5'-Aminocobalamin with an alkyne linker and azide-modified oligonucleotides enabled the synthesis of vitamin B12-2'OMeRNA conjugates using an efficient "click" methodology. Inhibition of protein expression in E. coli and S. Typhimurium cells indicates an unprecedented transport of 2'OMeRNA oligomers into bacterial cells via the vitamin B12 delivery pathway.
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Affiliation(s)
- Maciej Giedyk
- Institute of Organic Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
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103
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Kotil S, Jakobsson E. Rationally designing antisense therapy to keep up with evolving bacterial resistance. PLoS One 2019; 14:e0209894. [PMID: 30645595 PMCID: PMC6333403 DOI: 10.1371/journal.pone.0209894] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
Antisense molecules used as antibiotics offer the potential to keep up with acquired resistance, by redesigning the sequence of an antisense. Once bacteria acquire resistance by mutating the targeted sequence, new antisense can readily be designed by using sequence information of a target gene. However, antisense molecules require additional delivery vehicles to get into bacteria and be protected from degradation. Based on progress in the last few years it appears that, while redesigning or finding new delivery vehicle will be more difficult than redesigning the antisense cargo, it will perhaps be less difficult than finding new conventional small molecule antibiotics. In this study we propose a protocol that maximizes the combined advantages of engineered delivery vehicle and antisense cargo by decreasing the immediate growth advantage to the pathogen of mutating the entry mechanisms and increasing the advantage to the pathogen of antisense target mutations. Using this protocol, we show by computer simulation an appropriately designed antisense therapy can potentially be effective many times longer than conventional antibiotics before succumbing to resistance. While the simulations describe an in-vitro situation, based on comparison with other in-vitro studies on acquired resistance we believe the advantages of the combination antisense strategy have the potential to provide much more sustainability in vivo than conventional antibiotic therapy.
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Affiliation(s)
- Seyfullah Kotil
- Program in Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Eric Jakobsson
- Program in Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Molecular and Integrative Physiology, University of Illlinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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104
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Molecules that Inhibit Bacterial Resistance Enzymes. Molecules 2018; 24:molecules24010043. [PMID: 30583527 PMCID: PMC6337270 DOI: 10.3390/molecules24010043] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/14/2022] Open
Abstract
Antibiotic resistance mediated by bacterial enzymes constitutes an unmet clinical challenge for public health, particularly for those currently used antibiotics that are recognized as "last-resort" defense against multidrug-resistant (MDR) bacteria. Inhibitors of resistance enzymes offer an alternative strategy to counter this threat. The combination of inhibitors and antibiotics could effectively prolong the lifespan of clinically relevant antibiotics and minimize the impact and emergence of resistance. In this review, we first provide a brief overview of antibiotic resistance mechanism by bacterial secreted enzymes. Furthermore, we summarize the potential inhibitors that sabotage these resistance pathways and restore the bactericidal activity of inactive antibiotics. Finally, the faced challenges and an outlook for the development of more effective and safer resistance enzyme inhibitors are discussed.
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105
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Równicki M, Pieńko T, Czarnecki J, Kolanowska M, Bartosik D, Trylska J. Artificial Activation of Escherichia coli mazEF and hipBA Toxin-Antitoxin Systems by Antisense Peptide Nucleic Acids as an Antibacterial Strategy. Front Microbiol 2018; 9:2870. [PMID: 30534121 PMCID: PMC6275173 DOI: 10.3389/fmicb.2018.02870] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/08/2018] [Indexed: 12/14/2022] Open
Abstract
The search for new, non-standard targets is currently a high priority in the design of new antibacterial compounds. Bacterial toxin-antitoxin systems (TAs) are genetic modules that encode a toxin protein that causes growth arrest by interfering with essential cellular processes, and a cognate antitoxin, which neutralizes the toxin activity. TAs have no human analogs, are highly abundant in bacterial genomes, and therefore represent attractive alternative targets for antimicrobial drugs. This study demonstrates how artificial activation of Escherichia coli mazEF and hipBA toxin-antitoxin systems using sequence-specific antisense peptide nucleic acid oligomers is an innovative antibacterial strategy. The growth arrest observed in E. coli resulted from the inhibition of translation of the antitoxins by the antisense oligomers. Furthermore, two other targets, related to the activities of mazEF and hipBA, were identified as promising sites of action for antibacterials. These results show that TAs are susceptible to sequence-specific antisense agents and provide a proof-of-concept for their further exploitation in antimicrobial strategies.
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Affiliation(s)
- Marcin Równicki
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, Poland
| | - Tomasz Pieńko
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Department of Drug Chemistry, Faculty of Pharmacy with the Laboratory Medicine Division, Medical University of Warsaw, Warsaw, Poland
| | - Jakub Czarnecki
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
- Unit of Bacterial Genome Plasticity, Department of Genomes and Genetics, Pasteur Institute, Paris, France
| | - Monika Kolanowska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- Genomic Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Dariusz Bartosik
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
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106
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Sugimoto S, Maeda H, Kitamatsu M, Nishikawa I, Shida M. Selective growth inhibition of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans by antisense peptide nucleic acids. Mol Cell Probes 2018; 43:45-49. [PMID: 30471338 DOI: 10.1016/j.mcp.2018.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/13/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
Abstract
Peptide nucleic acids (PNA) are DNA/RNA analogs in which the sugar-phosphate backbone is replaced by N-2-aminoethylglycine. PNA are widely used for experimental antisense therapy due to their strong affinity to mRNA. By targeting specific genes, protein synthesis and the growth of bacteria or cancer cells can be inhibited by PNA. Here, we report the design and evaluation of antisense PNA for selective growth inhibition of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, potent pathogens associated with periodontitis. Antisense PNA against groEL and acpP were prepared with carrier peptide (KFFKFFKFFK). Anti-groEL PNA for P. gingivalis specifically inhibited growth in a dose-dependent manner, and growth was inhibited for 5 h at a concentration of 3 μM. Anti-groEL PNA for A. actinomycetemcomitans inhibited growth for 2 h at a concentration of 3 μM with reduced GroEL protein expression. Anti-acpP PNA did not show a marked growth inhibitory effect on either species. Although further studies are needed to develop more effective antisense PNA for both species, anti-groEL PNA may be potentially useful species-specific antibacterial tools against oral pathogens.
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Affiliation(s)
- Sadaomi Sugimoto
- Department of Endodontics, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka, 573-1121, Japan
| | - Hiroshi Maeda
- Department of Endodontics, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka, 573-1121, Japan.
| | - Mizuki Kitamatsu
- Department of Applied Chemistry, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka, 577-8502, Japan
| | - Ikuo Nishikawa
- Department of Endodontics, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka, 573-1121, Japan
| | - Muneyasu Shida
- Department of Endodontics, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka, 573-1121, Japan
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107
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Santos RS, Figueiredo C, Azevedo NF, Braeckmans K, De Smedt SC. Nanomaterials and molecular transporters to overcome the bacterial envelope barrier: Towards advanced delivery of antibiotics. Adv Drug Deliv Rev 2018; 136-137:28-48. [PMID: 29248479 DOI: 10.1016/j.addr.2017.12.010] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 01/13/2023]
Abstract
With the dramatic consequences of bacterial resistance to antibiotics, nanomaterials and molecular transporters have started to be investigated as alternative antibacterials or anti-infective carrier systems to improve the internalization of bactericidal drugs. However, the capability of nanomaterials/molecular transporters to overcome the bacterial cell envelope is poorly understood. It is critical to consider the sophisticated architecture of bacterial envelopes and reflect how nanomaterials/molecular transporters can interact with these envelopes, being the major aim of this review. The first part of this manuscript overviews the permeability of bacterial envelopes and how it limits the internalization of common antibiotic and novel oligonucleotide drugs. Subsequently we critically discuss the mechanisms that allow nanomaterials/molecular transporters to overcome the bacterial envelopes, focusing on the most promising ones to this end - siderophores, cyclodextrins, metal nanoparticles, antimicrobial/cell-penetrating peptides and fusogenic liposomes. This review may stimulate drug delivery and microbiology scientists in designing effective nanomaterials/molecular transporters against bacterial infections.
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108
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Magistro G, Magistro C, Stief CG, Schubert S. A simple and highly efficient method for gene silencing in Escherichia coli. J Microbiol Methods 2018; 154:25-32. [PMID: 30296471 DOI: 10.1016/j.mimet.2018.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 10/28/2022]
Abstract
Here we present a simple and rapidly achievable protocol for gene silencing in Escherichia coli (E. coli). In this procedure, antisense RNA (asRNA) of 400-nucleotides (nt) length and absolute complementarity to the target is produced by an expression plasmid. The designed asRNA should ideally cover at least the -10 site of the promoter and the Shine-Dalgarno sequence, and additional 300-bp of the following open reading frame of the target gene. We show that the transcription process of the target is not affected at all, whereas the translation process is impaired. Based on high constitutive expression of asRNA we were able to extend the silencing effect to knock-out levels. By inducible expression, we show that also the modulation is possible. This technique should be widely useful to study gene function in E. coli and other bacteria.
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Affiliation(s)
- Giuseppe Magistro
- Department of Urology, Ludwig-Maximilians-University, Munich, Germany.
| | - Christiane Magistro
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Munich, Germany
| | - Christian G Stief
- Department of Urology, Ludwig-Maximilians-University, Munich, Germany
| | - Sören Schubert
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Munich, Germany
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109
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Ghosh S, Saini S, Saraogi I. Peptide nucleic acid mediated inhibition of the bacterial signal recognition particle. Chem Commun (Camb) 2018; 54:8257-8260. [PMID: 29989112 DOI: 10.1039/c8cc04715d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have identified the bacterial signal recognition particle (SRP) as a novel antibacterial target. As a proof of principle, we used an antisense peptide nucleic acid to target a key SRP RNA. The PNA molecules showed efficient inhibition of SRP function and bacterial cell growth, thereby validating our hypothesis.
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Affiliation(s)
- Sudipta Ghosh
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, MP, India.
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110
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Antimicrobial synergy between mRNA targeted peptide nucleic acid and antibiotics in E. coli. Bioorg Med Chem Lett 2018; 28:3094-3098. [PMID: 30082123 DOI: 10.1016/j.bmcl.2018.07.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/18/2018] [Accepted: 07/26/2018] [Indexed: 11/22/2022]
Abstract
A combination of antibacterial agents should make the emergence of resistance in bacteria less probable. Thus we have analyzed the synergistic effects between antibacterial antisense peptide nucleic acids (PNA) and conventional antibiotics against Escherichia coli AS19 (lipopolysaccharide defective) strain and a derivative of a pathogenic strain E. coli O157:H7. PNAs were designed to target mRNA transcripts encoding the essential acyl carrier protein (gene acpP) and conjugated to the cell-penetrating peptide (KFF)3K for cellular uptake. Antibiotics included aminoglycosides, aminopenicillins, polymyxins, rifamycins, sulfonamides and trimethoprim. Synergies were evaluated using the checkerboard technique. Fractional Inhibitory Concentration indices (FICi) were calculated for all combinations based on the minimal inhibitory concentration of each individual agent. The results demonstrate two novel synergistic combinations of antimicrobial agents, namely, (KFF)3K-PNA anti-acpP with polymyxin B and (KFF)3K-PNA anti-acpP with trimethoprim (both with FICi = 0.38). Polymyxin B's synergy postulates cell wall targeted antibiotics as attractive agents to improve the uptake of PNA while trimethoprim's interaction with PNA my reveal a new inhibitory mechanism.
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111
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Jasiński M, Feig M, Trylska J. Improved Force Fields for Peptide Nucleic Acids with Optimized Backbone Torsion Parameters. J Chem Theory Comput 2018; 14:3603-3620. [PMID: 29791152 DOI: 10.1021/acs.jctc.8b00291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Peptide nucleic acids are promising nucleic acid analogs for antisense therapies as they can form stable duplex and triplex structures with DNA and RNA. Computational studies of PNA-containing duplexes and triplexes are an important component for guiding their design, yet existing force fields have not been well validated and parametrized with modern computational capabilities. We present updated CHARMM and Amber force fields for PNA that greatly improve the stability of simulated PNA-containing duplexes and triplexes in comparison with experimental structures and allow such systems to be studied on microsecond time scales. The force field modifications focus on reparametrized PNA backbone torsion angles to match high-level quantum mechanics reference energies for a model compound. The microsecond simulations of PNA-PNA, PNA-DNA, PNA-RNA, and PNA-DNA-PNA complexes also allowed a comprehensive analysis of hydration and ion interactions with such systems.
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Affiliation(s)
- Maciej Jasiński
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States.,Centre of New Technologies , University of Warsaw , Warsaw , Poland
| | - Michael Feig
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Joanna Trylska
- Centre of New Technologies , University of Warsaw , Warsaw , Poland
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112
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Daly SM, Sturge CR, Greenberg DE. Inhibition of Bacterial Growth by Peptide-Conjugated Morpholino Oligomers. Methods Mol Biol 2018; 1565:115-122. [PMID: 28364238 DOI: 10.1007/978-1-4939-6817-6_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Morpholino oligomers (MOs) are antisense molecules designed for sequence-specific binding of target mRNA. In bacteria, inhibition is hypothesized to occur by preventing translation initiation. Cell-penetrating peptides may be conjugated to the 5'- or 3'-termini of an MO to enhance cellular entry and therefore inhibition. Here we describe the three standard microbiological assays to assess in vitro antibacterial MO efficacy.
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Affiliation(s)
- Seth M Daly
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Carolyn R Sturge
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - David E Greenberg
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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113
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Xue XY, Mao XG, Zhou Y, Chen Z, Hu Y, Hou Z, Li MK, Meng JR, Luo XX. Advances in the delivery of antisense oligonucleotides for combating bacterial infectious diseases. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2018; 14:745-758. [PMID: 29341934 DOI: 10.1016/j.nano.2017.12.026] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/12/2017] [Accepted: 12/31/2017] [Indexed: 12/22/2022]
Abstract
Discovery and development of new antibacterial drugs against multidrug resistant bacterial strains have become more and more urgent. Antisense oligonucleotides (ASOs) show immense potential to control the spread of resistant microbes due to its high specificity of action, little risk to human gene expression, and easy design and synthesis to target any possible gene. However, efficient delivery of ASOs to their action sites with enough concentration remains a major obstacle, which greatly hampers their clinical application. In this study, we reviewed current progress on delivery strategies of ASOs into bacteria, focused on various non-virus gene vectors, including cell penetrating peptides, lipid nanoparticles, bolaamphiphile-based nanoparticles, DNA nanostructures and Vitamin B12. The current review provided comprehensive understanding and novel perspective for the future application of ASOs in combating bacterial infections.
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Affiliation(s)
- Xiao-Yan Xue
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China.
| | - Xing-Gang Mao
- Department of Neurosurgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Ying Zhou
- Department of Pharmacology, Xi'an Medical University, Xi'an, China
| | - Zhou Chen
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China
| | - Yue Hu
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China
| | - Zheng Hou
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China
| | - Ming-Kai Li
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China
| | - Jing-Ru Meng
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China
| | - Xiao-Xing Luo
- Department of Pharmacology, School of Pharmacy, The Fourth Military Medical University, Xi'an, China.
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114
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Oh E, Jeon B. Method of Peptide Nucleic Acid (PNA)-Mediated Antisense Inhibition of Gene Expression in Campylobacter jejuni. Methods Mol Biol 2018; 1512:43-49. [PMID: 27885597 DOI: 10.1007/978-1-4939-6536-6_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Peptide nucleic acid (PNA) is an oligonucleotide mimic that recognizes and binds to nucleic acids. The strong binding affinity of PNA to mRNA coupled with its high sequence specificity enable antisense PNA to selectively inhibit (i.e., knockdown) the protein synthesis of a target gene. This novel technology provides a powerful tool for Campylobacter studies because molecular techniques have been relatively less well-developed for this bacterium as compared to other pathogens, such as Escherichia coli and Salmonella. This chapter describes a protocol for PNA-mediated antisense inhibition of gene expression in Campylobacter jejuni.
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Affiliation(s)
- Euna Oh
- School of Public Health, University of Alberta, 116th Street and 85 Avenue, Edmonton, AB, Canada, T6G 2 R3
| | - Byeonghwa Jeon
- School of Public Health, University of Alberta, 116th Street and 85 Avenue, Edmonton, AB, Canada, T6G 2 R3.
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115
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Costerton WJ, Montanaro L, Balaban N, Arciola CR. Prospecting Gene Therapy of Implant Infections. Int J Artif Organs 2018; 32:689-95. [DOI: 10.1177/039139880903200919] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Infection still represents one of the most serious and ravaging complications associated with prosthetic devices. Staphylococci and enterococci, the bacteria most frequently responsible for orthopedic postsurgical and implant-related infections, express clinically relevant antibiotic resistance. The emergence of antibiotic-resistant bacteria and the slow progress in identifying new classes of antimicrobial agents have encouraged research into novel therapeutic strategies. The adoption of antisense or “antigene” molecules able to silence or knock-out bacterial genes responsible for their virulence is one possible innovative approach. Peptide nucleic acids (PNAs) are potential drug candidates for gene therapy in infections, by silencing a basic gene of bacterial growth or by tackling the antibiotic resistance or virulence factors of a pathogen. An efficacious contrast to bacterial genes should be set up in the first stages of infection in order to prevent colonization of periprosthesis tissues. Genes encoding bacterial factors for adhesion and colonization (biofilm and/or adhesins) would be the best candidates for gene therapy. But after initial enthusiasm for direct antisense knock-out or silencing of essential or virulence bacterial genes, difficulties have emerged; consequently, new approaches are now being attempted. One of these, interference with the regulating system of virulence factors, such as agr, appears particularly promising.
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Affiliation(s)
- William J. Costerton
- Center for Genomic Sciences Allegheny-Singer Research Institute, Pittsburgh, Pennsylvania - USA
| | - Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopedic Institute, Bologna - Italy
- Experimental Pathology Department, University of Bologna, Bologna - Italy
| | - Naomi Balaban
- Department of Biomedical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts - USA
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopedic Institute, Bologna - Italy
- Experimental Pathology Department, University of Bologna, Bologna - Italy
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116
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Elskens J, Manicardi A, Costi V, Madder A, Corradini R. Synthesis and Improved Cross-Linking Properties of C5-Modified Furan Bearing PNAs. Molecules 2017; 22:molecules22112010. [PMID: 29156637 PMCID: PMC6150320 DOI: 10.3390/molecules22112010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 11/07/2017] [Accepted: 11/09/2017] [Indexed: 12/21/2022] Open
Abstract
Over the past decades, peptide nucleic acid/DNA (PNA:DNA) duplex stability has been improved via backbone modification, often achieved via introducing an amino acid side chain at the α- or γ-position in the PNA sequence. It was previously shown that interstrand cross-linking can further enhance the binding event. In this work, we combined both strategies to fine-tune PNA crosslinking towards single stranded DNA sequences using a furan oxidation-based crosslinking method; for this purpose, γ-l-lysine and γ-l-arginine furan-PNA monomers were synthesized and incorporated in PNA sequences via solid phase synthesis. It was shown that the l-lysine γ-modification had a beneficial effect on crosslink efficiency due to pre-organization of the PNA helix and a favorable electrostatic interaction between the positively-charged lysine and the negatively-charged DNA backbone. Moreover, the crosslink yield could be optimized by carefully choosing the type of furan PNA monomer. This work is the first to describe a selective and biocompatible furan crosslinking strategy for crosslinking of γ-modified PNA sequences towards single-stranded DNA.
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Affiliation(s)
- Joke Elskens
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, 9000 Gent, Belgium.
| | - Alex Manicardi
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, 9000 Gent, Belgium.
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Valentina Costi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Annemieke Madder
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, 9000 Gent, Belgium.
| | - Roberto Corradini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
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117
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Równicki M, Wojciechowska M, Wierzba AJ, Czarnecki J, Bartosik D, Gryko D, Trylska J. Vitamin B 12 as a carrier of peptide nucleic acid (PNA) into bacterial cells. Sci Rep 2017; 7:7644. [PMID: 28794451 PMCID: PMC5550456 DOI: 10.1038/s41598-017-08032-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/06/2017] [Indexed: 01/02/2023] Open
Abstract
Short modified oligonucleotides targeted at bacterial DNA or RNA could serve as antibacterial agents provided that they are efficiently taken up by bacterial cells. However, the uptake of such oligonucleotides is hindered by the bacterial cell wall. To overcome this problem, oligomers have been attached to cell-penetrating peptides, but the efficiency of delivery remains poor. Thus, we have investigated the ability of vitamin B12 to transport peptide nucleic acid (PNA) oligomers into cells of Escherichia coli and Salmonella Typhimurium. Vitamin B12 was covalently linked to a PNA oligomer targeted at the mRNA of a reporter gene expressing Red Fluorescent Protein. Cu-catalyzed 1,3-dipolar cycloaddition was employed for the synthesis of PNA-vitamin B12 conjugates; namely the vitamin B12 azide was reacted with PNA possessing the terminal alkyne group. Different types of linkers and spacers between vitamin B12 and PNA were tested, including a disulfide bond. We found that vitamin B12 transports antisense PNA into E. coli cells more efficiently than the most widely used cell-penetrating peptide (KFF)3K. We also determined that the structure of the linker impacts the antisense effect. The results of this study provide the foundation for developing vitamin B12 as a carrier of PNA oligonucleotides into bacterial cells.
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Affiliation(s)
- Marcin Równicki
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, Banacha 2c, 02-097, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Aleksandra J Wierzba
- Institute of Organic Chemistry, Polish Academy of Sciences, M. Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Jakub Czarnecki
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Dariusz Bartosik
- Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Dorota Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, M. Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.
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118
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Nakano K, Tanabe J, Ishimatsu R, Imato T. Monolithic Peptide-Nucleic Acid Hybrid Functioning as an Artificial Microperoxidase. Bioconjug Chem 2017; 28:2031-2034. [PMID: 28696677 DOI: 10.1021/acs.bioconjchem.7b00216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new peptide nucleic acid (PNA) with an installed peroxidase function has been developed. Fmoc solid phase peptide synthesis prepared a PNA hybrid (VQKCAQCHTVE-(C2H4O)2CH2-[PNA(T)]6-G) that renders the microperoxidase backbone, followed by reconstitution with hemin. The resulting holocompound catalyzed the oxidation of 3,3',5,5'-tetramthylbenzidine by H2O2 to 50% that of natural microperoxidase-11, whereas the apo-form and hemin gave no responses. The peroxidase domain was found to be active toward direct electrochemistry and the PNA hybrid served for gene sensor; in the presence of the target DNA (5'-CATGTATAAAAAA-3'), an electrode-attached DNA probe (5'-TsTsTsTsTsTCTCATACATG-3') showed the ferric-to-ferrous quasi-reversible wave (-276 mV vs Ag/AgCl) through sandwich hybridization. Moreover, the hybridization product could accept H2O2 as an oxidant to enhance the reduction current, which occurred likely based on the iron(II)-center-recycling with specific rate constant of 0.19 s-1.
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Affiliation(s)
- Koji Nakano
- Department of Applied Chemistry, Faculty of Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka, Japan
| | - Junichi Tanabe
- Department of Applied Chemistry, Faculty of Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka, Japan
| | - Ryoich Ishimatsu
- Department of Applied Chemistry, Faculty of Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka, Japan
| | - Toshihiko Imato
- Department of Applied Chemistry, Faculty of Engineering, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka, Japan
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119
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Peptide nucleic acids (PNAs): currently potential bactericidal agents. Biomed Pharmacother 2017; 93:580-588. [PMID: 28686972 DOI: 10.1016/j.biopha.2017.06.092] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 06/12/2017] [Accepted: 06/23/2017] [Indexed: 01/09/2023] Open
Abstract
In recent years, the emergence of ESBL-producing and multi-drug resistant bacteria have been increased and designing novel components is necessary for confrontation these bacteria. Peptide nucleic acids (PNAs) are one of the synthetic components that bind to single strand DNA and RNA. Applications of these components are wide while, and one of the important applications of these components is inhibition of gene expression and knock downing the target gene follow as inhibition of bacterial growth. For PNA targeting gene, peptide-PNAs (PPNA) activity cannot be occurred without sequence homology, at the same time, it has been affected by sequence-based specific target and dose-dependent-based manner. Choosing the conserved sequence in different bacterial genus can provide broad-spectrum antimicrobial activity. In this review article, we studied several research papers and extract PNA targeting genes that cause gene knock down and inhibition of bacterial growth. Some novel opportunities for advancement and the design ultra-narrow-spectrum antimicrobial drugs against multi-drug can be accessible by utilizing PNA against necessary genes of pathogens. These results open novel vision for therapeutic intervention. Future researches are required to evaluate the safety, toxicity and pharmacokinetics properties of PPNAs in order to be utilized in clinical treatment.
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120
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Kamaruzzaman NF, Kendall S, Good L. Targeting the hard to reach: challenges and novel strategies in the treatment of intracellular bacterial infections. Br J Pharmacol 2017; 174:2225-2236. [PMID: 27925153 PMCID: PMC5481648 DOI: 10.1111/bph.13664] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/20/2016] [Accepted: 10/06/2016] [Indexed: 12/22/2022] Open
Abstract
Infectious diseases continue to threaten human and animal health and welfare globally, impacting millions of lives and causing substantial economic loss. The use of antibacterials has been only partially successful in reducing disease impact. Bacterial cells are inherently resilient, and the therapy challenge is increased by the development of antibacterial resistance, the formation of biofilms and the ability of certain clinically important pathogens to invade and localize within host cells. Invasion into host cells provides protection from both antibacterials and the host immune system. Poor delivery of antibacterials into host cells causes inadequate bacterial clearance, resulting in chronic and unresolved infections. In this review, we discuss the challenges associated with existing antibacterial therapies with a focus on intracellular pathogens. We consider the requirements for successful treatment of intracellular infections and novel platforms currently under development. Finally, we discuss novel strategies to improve drug penetration into host cells. As an example, we discuss our recent demonstration that the cell penetrating cationic polymer polyhexamethylene biguanide has antibacterial activity against intracellular Staphylococcus aureus. LINKED ARTICLES This article is part of a themed section on Drug Metabolism and Antibiotic Resistance in Micro-organisms. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.14/issuetoc.
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Affiliation(s)
- Nor Fadhilah Kamaruzzaman
- Department of Pathology and Pathogen BiologyRoyal Veterinary College, University of LondonNW10TUUK
- Faculty of Veterinary MedicineUniversiti Malaysia KelantanLocked Bag 36, Pengkalan Chepa16100Kota BharuKelantanMalaysia
| | - Sharon Kendall
- Department of Pathology and Pathogen BiologyRoyal Veterinary College, University of LondonNW10TUUK
| | - Liam Good
- Department of Pathology and Pathogen BiologyRoyal Veterinary College, University of LondonNW10TUUK
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121
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Purification and characterization of lipase by Bacillus methylotrophicus PS3 under submerged fermentation and its application in detergent industry. J Genet Eng Biotechnol 2017; 15:369-377. [PMID: 30647675 PMCID: PMC6296573 DOI: 10.1016/j.jgeb.2017.06.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/07/2017] [Accepted: 06/10/2017] [Indexed: 11/20/2022]
Abstract
Lipase production bacterial isolate was isolated from soil of service station and identified as Bacillus methylotrophicus PS3 by 16SrRNA with accession number |LN999829.1|. Lipase enzyme was purified by sequential methods of ammonium sulfate precipitation and Sephadex G-100 gel column chromatography. The molecular weight of purified enzyme was 31.40 kDa on SDS-PAGE. This purification procedure resulted in 2.90-fold purification of lipase with a 24.10% final yield. The purified lipase presented maximal hydrolytic activity at a temperature of 55 °C, and pH of 7.0. Lipase activity was stimulated by Triton X-100 and SDS with Mg2+ and Ca2+ metals employ a positive effect and outlast its stable in organic solvent i.e. methanol and ethanol.
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122
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Kulik M, Markowska-Zagrajek A, Wojciechowska M, Grzela R, Wituła T, Trylska J. Helix 69 of Escherichia coli 23S ribosomal RNA as a peptide nucleic acid target. Biochimie 2017; 138:32-42. [PMID: 28396015 DOI: 10.1016/j.biochi.2017.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 03/03/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
A fragment of 23S ribosomal RNA (nucleotides 1906-1924 in E. coli), termed Helix 69, forms a hairpin that is essential for ribosome function. Helix 69 forms a conformationally flexible inter-subunit connection with helix 44 of 16S ribosomal RNA, and the nucleotide A1913 of Helix 69 influences decoding accuracy. Nucleotides U1911 and U1917 are post-transcriptionally modified with pseudouridines (Ψ) and U1915 with 3-methyl-Ψ. We investigated Helix 69 as a target for a complementary synthetic oligonucleotide - peptide nucleic acid (PNA). We determined thermodynamic properties of Helix 69 and its complexes with PNA and tested the performance of PNA targeted at Helix 69 in inhibiting translation in cell-free extracts and growth of E. coli cells. First, we examined the interactions of a PNA oligomer complementary to the G1907-A1919 fragment of Helix 69 with the sequences corresponding to human and bacterial species (with or without pseudouridine modifications). PNA invades the Helix 69 hairpin creating stable complexes and PNA binding to the pseudouridylated bacterial sequence is stronger than to Helix 69 without any modifications. Second, we confirmed the binding of PNA to 23S rRNA and 70S ribosomes. Third, we verified the efficiency of translation inhibition of these PNA oligomers in the cell-free translation/transcription E. coli system, which were in a similar range as tetracycline. Next, we confirmed that PNA conjugated to the (KFF)3K transporter peptide inhibited E. coli growth in micromolar concentrations. Overall, targeting Helix 69 with PNA or other sequence-specific oligomers could be a promising way to inhibit bacterial translation.
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Affiliation(s)
- Marta Kulik
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland; Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - Agnieszka Markowska-Zagrajek
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland; Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Renata Grzela
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Tomasz Wituła
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.
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123
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Pieńko T, Wierzba AJ, Wojciechowska M, Gryko D, Trylska J. Conformational Dynamics of Cyanocobalamin and Its Conjugates with Peptide Nucleic Acids. J Phys Chem B 2017; 121:2968-2979. [PMID: 28301169 DOI: 10.1021/acs.jpcb.7b00649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Vitamin B12 also called cobalamin (Cbl) is an important enzymatic cofactor taken up by mammalian and also by many bacterial cells. Peptide nucleic acid (PNA) is a synthetic DNA analogue that has the ability to bind in a complementary manner to natural nucleic acids. Provided that PNA is efficiently delivered to cells, it could act as a steric blocker of functional DNA or RNA and regulate gene expression at the level of transcription or translation. Recently, Cbl has been examined as a transporter of various molecules to cells. Also, PNA, if covalently linked with Cbl, can be delivered to bacterial cells, but it is crucial to verify that Cbl does not change the desired PNA biological properties. We have analyzed the structure and conformational dynamics of conjugates of Cbl with a PNA monomer and oligomer. We synthesized a cyanocobalamin derivative with a PNA monomer C connected via the triazole linker and determined its NMR spectra. Using microsecond-long molecular dynamics simulations, we examined the internal dynamics of cyanocobalamin-C, its conjugate with a 14-mer PNA, and free PNA. The results suggest that all compounds acquire rather compact structures but the PNA oligomer conformations vary. For the Cbl-C conjugate the cross-peaks from the ROESY spectrum corroborated with the clusters from molecular dynamics trajectories. Within PNA the dominant interaction is stacking but the stacking bases are not necessarily neighboring in the PNA sequence. More bases stack in free PNA than in PNA of the conjugate, but stacking is less stable in free PNA. PNA in the conjugate is slightly more exposed to solvent. Overall, cyanocobalamin attached to a PNA oligomer increases the flexibility of PNA in a way that could be beneficial for its hybridization with natural nucleic acid oligomers.
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Affiliation(s)
- Tomasz Pieńko
- Centre of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland.,Department of Drug Chemistry, Faculty of Pharmacy with the Laboratory Medicine Division, Medical University of Warsaw , S. Banacha 1a, 02-097 Warsaw, Poland
| | - Aleksandra J Wierzba
- Institute of Organic Chemistry, Polish Academy of Sciences , M. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland
| | - Dorota Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences , M. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw , S. Banacha 2c, 02-097 Warsaw, Poland
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124
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Thoduka SG, Zaleski PA, Dąbrowska Z, Równicki M, Stróżecka J, Górska A, Olejniczak M, Trylska J. Analysis of ribosomal inter-subunit sites as targets for complementary oligonucleotides. Biopolymers 2017; 107. [PMID: 27858985 DOI: 10.1002/bip.23004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 10/06/2016] [Accepted: 11/10/2016] [Indexed: 01/15/2023]
Abstract
The bacterial ribosome has many functional ribosomal RNA (rRNA) sites. We have computationally analyzed the rRNA regions involved in the interactions between the 30S and 50S subunits. Various properties of rRNA such as solvent accessibility, opening energy, hydrogen bonding pattern, van der Waals energy, thermodynamic stability were determined. Based on these properties we selected rRNA targets for hybridization with complementary 2'-O-methyl oligoribonucleotides (2'-OMe RNAs). Further, the inhibition efficiencies of the designed ribosome-interfering 2'-OMe RNAs were tested using a β-galactosidase assay in a translation system based on the E. coli extract. Several of the oligonucleotides displayed IC50 values below 1 μM, which were in a similar range as those determined for known ribosome inhibitors, tetracycline and pactamycin. The calculated opening and van der Waals stacking energies of the rRNA targets correlated best with the inhibitory efficiencies of 2'-OMe RNAs. Moreover, the binding affinities of several oligonucleotides to both 70S ribosomes and isolated 30S and 50S subunits were measured using a double-filter retention assay. Further, we applied heat-shock chemical transformation to introduce 2'-OMe RNAs to E. coli cells and verify inhibition of bacterial growth. We observed high correlation between IC50 in the cell-free extract and bacterial growth inhibition. Overall, the results suggest that the computational analysis of potential rRNA targets within the conformationally dynamic regions of inter-subunit bridges can help design efficient antisense oligomers to probe the ribosome function.
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Affiliation(s)
- Sapna G Thoduka
- Centre of New Technologies, University of Warsaw, Warsaw, 02-097, Poland
| | - Paul A Zaleski
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznań, Poznań, 61-614, Poland
| | - Zofia Dąbrowska
- Centre of New Technologies, University of Warsaw, Warsaw, 02-097, Poland
| | - Marcin Równicki
- Centre of New Technologies, University of Warsaw, Warsaw, 02-097, Poland.,College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Banacha 2c, Warsaw, 02-097, Poland
| | - Joanna Stróżecka
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznań, Poznań, 61-614, Poland
| | - Anna Górska
- Centre of New Technologies, University of Warsaw, Warsaw, 02-097, Poland
| | - Mikołaj Olejniczak
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznań, Poznań, 61-614, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Warsaw, 02-097, Poland
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125
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Otsuka T, Brauer AL, Kirkham C, Sully EK, Pettigrew MM, Kong Y, Geller BL, Murphy TF. Antimicrobial activity of antisense peptide-peptide nucleic acid conjugates against non-typeable Haemophilus influenzae in planktonic and biofilm forms. J Antimicrob Chemother 2016; 72:137-144. [PMID: 27986898 DOI: 10.1093/jac/dkw384] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/10/2016] [Accepted: 08/16/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Antisense peptide nucleic acids (PNAs) are synthetic polymers that mimic DNA/RNA and inhibit bacterial gene expression in a sequence-specific manner. METHODS To assess activity against non-typeable Haemophilus influenzae (NTHi), we designed six PNA-peptides that target acpP, encoding an acyl carrier protein. MICs and minimum biofilm eradication concentrations (MBECs) were determined. Resistant strains were selected by serial passages on media with a sub-MIC concentration of acpP-PNA. RESULTS The MICs of six acpP-PNA-peptides were 2.9-11 mg/L (0.63-2.5 μmol/L) for 20 clinical isolates, indicating susceptibility of planktonic NTHi. By contrast, MBECs were up to 179 mg/L (40 μmol/L). Compared with one original PNA-peptide (acpP-PNA1-3'N), an optimized PNA-peptide (acpP-PNA14-5'L) differs in PNA sequence and has a 5' membrane-penetrating peptide with a linker between the PNA and peptide. The optimized PNA-peptide had an MBEC ranging from 11 to 23 mg/L (2.5-5 μmol/L), indicating susceptibility. A resistant strain that was selected by the original acpP-PNA1-3'N had an SNP that introduced a stop codon in NTHI0044, which is predicted to encode an ATP-binding protein of a conserved ABC transporter. Deletion of NTHI0044 caused resistance to the original acpP-PNA1-3'N, but showed no effect on susceptibility to the optimized acpP-PNA14-5'L. The WT strain remained susceptible to the optimized PNA-peptide after 30 serial passages on media containing the optimized PNA-peptide. CONCLUSIONS A PNA-peptide that targets acpP, has a 5' membrane-penetrating peptide and has a linker shows excellent activity against planktonic and biofilm NTHi and is associated with a low risk for induction of resistance.
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Affiliation(s)
- Taketo Otsuka
- Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA.,Clinical and Translational Research Center, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Aimee L Brauer
- Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA.,Clinical and Translational Research Center, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Charmaine Kirkham
- Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA.,Clinical and Translational Research Center, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Erin K Sully
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Melinda M Pettigrew
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, USA
| | - Yong Kong
- Department of Molecular Biophysics and Biochemistry, W.M. Keck Foundation Biotechnology Resource Laboratory, Yale University, New Haven, CT, USA
| | - Bruce L Geller
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Timothy F Murphy
- Division of Infectious Diseases, Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA .,Clinical and Translational Research Center, University at Buffalo, State University of New York, Buffalo, NY, USA.,Department of Microbiology and Immunology, University at Buffalo, State University of New York, Buffalo, NY, USA
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126
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Sharma C, Awasthi SK. Versatility of peptide nucleic acids (PNAs): role in chemical biology, drug discovery, and origins of life. Chem Biol Drug Des 2016; 89:16-37. [PMID: 27490868 DOI: 10.1111/cbdd.12833] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 06/03/2016] [Accepted: 07/28/2016] [Indexed: 12/16/2022]
Abstract
This review briefly discussed nomenclature, synthesis, chemistry, and biophysical properties of a plethora of PNA derivatives reported since the discovery of aegPNA. Different synthetic methods and structural analogs of PNA synthesized till date were also discussed. An insight was gained into various chemical, physical, and biological properties of PNA which make it preferable over all other classes of modified nucleic acid analogs. Thereafter, various approaches with special attention to the practical constraints, characteristics, and inherent drawbacks leading to the delay in the development of PNA as gene therapeutic drug were outlined. An explicit account of the successful application of PNA in different areas of research such as antisense and antigene strategies, diagnostics, molecular probes, and so forth was described along with the current status of PNA as gene therapeutic drug. Further, the plausibility of the existence of PNA and its role in primordial chemistry, that is, origin of life was explored in an endeavor to comprehend the mystery and open up its deepest secrets ever engaging and challenging the human intellect. We finally concluded it with a discussion on the future prospects of PNA technology in the field of therapeutics, diagnostics, and origin of life.
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Affiliation(s)
- Chiranjeev Sharma
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi, Delhi, India
| | - Satish Kumar Awasthi
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi, Delhi, India
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127
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Maekawa K, Azuma M, Okuno Y, Tsukamoto T, Nishiguchi K, Setsukinai KI, Maki H, Numata Y, Takemoto H, Rokushima M. Antisense peptide nucleic acid–peptide conjugates for functional analyses of genes in Pseudomonas aeruginosa. Bioorg Med Chem 2016; 23:7234-9. [PMID: 26602085 DOI: 10.1016/j.bmc.2015.10.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 10/13/2015] [Indexed: 11/29/2022]
Abstract
Pseudomonas aeruginosa is one of the most common and clinically important pathogens because of its resistance to a wide variety of antibiotics. A number of treatments of P. aeruginosa have been developed, but there is still no definitive one. Antisense drugs have a great potential to treat multidrug-resistant P. aeruginosa because this technology, in principle, can inhibit the expression of any essential genes. Nucleic Acid Ther.2012, 22, 323 reported that peptide nucleic acid (PNA) antisenses conjugated to the carrier peptide (RXR)4 and targeted to ftsZ and acpP (essential genes) had antibacterial activity in P. aeruginosa. However, growth inhibition was also found with peptide-PNA antisense conjugates of mismatched sequences (negative controls), and hence there remains a possibility for considerable enhancement of basal level activity due to the general toxicity. To assess the true potential of peptide-PNA conjugates, we measured sequence-dependent knockdown of the (RXR)4-PNA conjugates by using a scrambled sequence as a negative control. In addition, we evaluated (RXR)4-PNA antisenses against three other essential genes (lepB, lptD and mraY) and a non-essential gene (PA1303), and confirmed that multiple sequences targeting only the essential genes showed antimicrobial activity in P. aeruginosa PAO1 cells. We also conducted a rescue experiment and confirmed that the antimicrobial activity of anti-mraY antisenses was an on-target effect, not due to general toxicity. These findings indicate that the (RXR)4–PNA antisense should be a useful tool for target validation of a specific gene and could be a therapeutic platform capable of targeting a variety of genes in P. aeruginosa.
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128
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Sully EK, Geller BL. Antisense antimicrobial therapeutics. Curr Opin Microbiol 2016; 33:47-55. [PMID: 27375107 PMCID: PMC5069135 DOI: 10.1016/j.mib.2016.05.017] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/17/2016] [Accepted: 05/31/2016] [Indexed: 01/17/2023]
Abstract
Antisense antimicrobial therapeutics are synthetic oligomers that silence expression of specific genes. This specificity confers an advantage over broad-spectrum antibiotics by avoiding unintended effects on commensal bacteria. The sequence-specificity and short length of antisense antimicrobials also pose little risk to human gene expression. Because antisense antimicrobials are a platform technology, they can be rapidly designed and synthesized to target almost any microbe. This reduces drug discovery time, and provides flexibility and a rational approach to drug development. Recent work has shown that antisense technology has the potential to address the antibiotic-resistance crisis, since resistance mechanisms for standard antibiotics apparently have no effect on antisense antimicrobials. Here, we describe current reports of antisense antimicrobials targeted against viruses, parasites, and bacteria.
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Affiliation(s)
- Erin K Sully
- Department of Microbiology, 226 Nash Hall, Oregon State University, Corvallis, OR 97331-3804, USA
| | - Bruce L Geller
- Department of Microbiology, 226 Nash Hall, Oregon State University, Corvallis, OR 97331-3804, USA.
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129
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Górska A, Markowska-Zagrajek A, Równicki M, Trylska J. Scanning of 16S Ribosomal RNA for Peptide Nucleic Acid Targets. J Phys Chem B 2016; 120:8369-78. [PMID: 27105576 DOI: 10.1021/acs.jpcb.6b02081] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have designed a protocol and server to aid in the search for putative binding sites in 16S rRNA that could be targeted by peptide nucleic acid oligomers. Various features of 16S rRNA were considered to score its regions as potential targets for sequence-specific binding that could result in inhibition of ribosome function. Specifically, apart from the functional importance of a particular rRNA region, we calculated its accessibility, flexibility, energetics of strand invasion by an oligomer, as well as similarity to human rRNA. To determine 16S rRNA flexibility in the ribosome context, we performed all-atom molecular dynamics simulations of the 30S subunit in explicit solvent. We proposed a few 16S RNA target sites, and one of them was tested experimentally to verify inhibition of bacterial growth by a peptide nucleic acid oligomer.
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Affiliation(s)
- Anna Górska
- Centre of New Technologies, University of Warsaw , Banacha 2c, 02-097 Warsaw, Poland
| | - Agnieszka Markowska-Zagrajek
- Centre of New Technologies, University of Warsaw , Banacha 2c, 02-097 Warsaw, Poland.,Department of Biology, University of Warsaw , Miecznikowa 1, 02-096 Warsaw, Poland
| | - Marcin Równicki
- Centre of New Technologies, University of Warsaw , Banacha 2c, 02-097 Warsaw, Poland.,College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences , Banacha 2c, 02-097 Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw , Banacha 2c, 02-097 Warsaw, Poland
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130
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GUO ZHENGRONG, PENG HUANYAN, KANG JIWEN, SUN DIANXING. Cell-penetrating peptides: Possible transduction mechanisms and therapeutic applications. Biomed Rep 2016; 4:528-534. [PMID: 27123243 PMCID: PMC4840506 DOI: 10.3892/br.2016.639] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/09/2016] [Indexed: 01/09/2023] Open
Abstract
Cell-penetrating peptides (CPPs), also known as protein transduction domains, are a class of diverse peptides with 5-30 amino acids. CPPs are divided into cationic, amphipathic and hydrophobic CPPs. They are able to carry small molecules, plasmid DNA, small interfering RNA, proteins, viruses, imaging agents and other various nanoparticles across the cellular membrane, resulting in internalization of the intact cargos. However, the mechanisms of CPP internalization remain to be elucidated. Recently, CPPs have received considerable attention due to their high transduction efficiency and low cytotoxicity. These peptides have a significant potential for diagnostic and therapeutic applications, such as delivery of fluorescent or radioactive compounds for imaging, delivery of peptides and proteins for therapeutic application, and delivery of molecules into induced pluripotent stem cells for directing differentiation. The present study reviews the classifications and transduction mechanisms of CPPs, as well as their potential applications.
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Affiliation(s)
- ZHENGRONG GUO
- The Liver Diseases Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, Hebei 050082, P.R. China
- Department of Gastroenterology, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - HUANYAN PENG
- The Liver Diseases Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, Hebei 050082, P.R. China
- Hebei Medical University Graduate School, Shijiazhuang, Hebei 050017, P.R. China
| | - JIWEN KANG
- The Liver Diseases Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, Hebei 050082, P.R. China
| | - DIANXING SUN
- The Liver Diseases Diagnosis and Treatment Center of PLA, Bethune International Peace Hospital, Shijiazhuang, Hebei 050082, P.R. China
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131
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Readman JB, Dickson G, Coldham NG. Translational Inhibition of CTX-M Extended Spectrum β-Lactamase in Clinical Strains of Escherichia coli by Synthetic Antisense Oligonucleotides Partially Restores Sensitivity to Cefotaxime. Front Microbiol 2016; 7:373. [PMID: 27047482 PMCID: PMC4805641 DOI: 10.3389/fmicb.2016.00373] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/08/2016] [Indexed: 11/13/2022] Open
Abstract
Synthetic antisense oligomers are DNA mimics that can specifically inhibit gene expression at the translational level by ribosomal steric hindrance. They bind to their mRNA targets by Watson-Crick base pairing and are resistant to degradation by both nucleases and proteases. A 25-mer phosphorodiamidate morpholino oligomer (PMO) and a 13-mer polyamide (peptide) nucleic acid (PNA) were designed to target mRNA (positions -4 to +21, and -17 to -5, respectively) close to the translational initiation site of the extended-spectrum β-lactamase resistance genes of CTX-M group 1. These antisense oligonucleotides were found to inhibit β-lactamase activity by up to 96% in a cell-free translation-transcription coupled system using an expression vector carrying a bla CTX-M-15 gene cloned from a clinical isolate. Despite evidence for up-regulation of CTX-M gene expression, they were both found to significantly restore sensitivity to cefotaxime (CTX) in E. coli AS19, an atypical cell wall permeable mutant, in a dose dependant manner (0-40 nM). The PMO and PNA were covalently bound to the cell penetrating peptide (CPP; (KFF)3K) and both significantly (P < 0.05) increased sensitivity to CTX in a dose dependent manner (0-40 nM) in field and clinical isolates harboring CTX-M group 1 β-lactamases. Antisense oligonucleotides targeted to the translational initiation site and Shine-Dalgarno region of bla CTX-M-15 inhibited gene expression, and when conjugated to a cell penetrating delivery vehicle, partially restored antibiotic sensitivity to both field and clinical isolates.
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Affiliation(s)
- John B Readman
- Bacteriology Department, Animal and Plant Health AgencySurrey, UK; Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of LondonSurrey, UK
| | - George Dickson
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of London Surrey, UK
| | - Nick G Coldham
- Bacteriology Department, Animal and Plant Health Agency Surrey, UK
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132
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The antimicrobial polymer PHMB enters cells and selectively condenses bacterial chromosomes. Sci Rep 2016; 6:23121. [PMID: 26996206 PMCID: PMC4800398 DOI: 10.1038/srep23121] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 02/29/2016] [Indexed: 11/08/2022] Open
Abstract
To combat infection and antimicrobial resistance, it is helpful to elucidate drug mechanism(s) of action. Here we examined how the widely used antimicrobial polyhexamethylene biguanide (PHMB) kills bacteria selectively over host cells. Contrary to the accepted model of microbial membrane disruption by PHMB, we observed cell entry into a range of bacterial species, and treated bacteria displayed cell division arrest and chromosome condensation, suggesting DNA binding as an alternative antimicrobial mechanism. A DNA-level mechanism was confirmed by observations that PHMB formed nanoparticles when mixed with isolated bacterial chromosomal DNA and its effects on growth were suppressed by pairwise combination with the DNA binding ligand Hoechst 33258. PHMB also entered mammalian cells, but was trapped within endosomes and excluded from nuclei. Therefore, PHMB displays differential access to bacterial and mammalian cellular DNA and selectively binds and condenses bacterial chromosomes. Because acquired resistance to PHMB has not been reported, selective chromosome condensation provides an unanticipated paradigm for antimicrobial action that may not succumb to resistance.
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133
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Hansen AM, Bonke G, Larsen CJ, Yavari N, Nielsen PE, Franzyk H. Antibacterial Peptide Nucleic Acid-Antimicrobial Peptide (PNA-AMP) Conjugates: Antisense Targeting of Fatty Acid Biosynthesis. Bioconjug Chem 2016; 27:863-7. [PMID: 26938833 DOI: 10.1021/acs.bioconjchem.6b00013] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Antisense peptide nucleic acid (PNA) oligomers constitute a novel class of potential antibiotics that inhibit bacterial growth via specific knockdown of essential gene expression. However, discovery of efficient, nontoxic delivery vehicles for such PNA oligomers has remained a challenge. In the present study we show that antimicrobial peptides (AMPs) with an intracellular mode of action can be efficient vehicles for bacterial delivery of an antibacterial PNA targeting the essential acpP gene. The results demonstrate that buforin 2-A (BF2-A), drosocin, oncocin 10, Pep-1-K, KLW-9,13-a, (P59→W59)-Tat48-60, BF-2A-RXR, and drosocin-RXR are capable of transporting PNA effectively into E. coli (MICs of 1-4 μM). Importantly, presence of the inner-membrane peptide transporter SbmA was not required for antibacterial activity of PNA-AMP conjugates containing Pep-1-K, KLW-9,13-a, or drosocin-RXR (MICs of 2-4 μM).
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Affiliation(s)
- Anna Mette Hansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Gitte Bonke
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Camilla Josephine Larsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Niloofar Yavari
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, Panum Institute, University of Copenhagen , Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Peter E Nielsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.,Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, Panum Institute, University of Copenhagen , Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark
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134
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Jackson A, Jani S, Sala CD, Soler-Bistué AJC, Zorreguieta A, Tolmasky ME. Assessment of configurations and chemistries of bridged nucleic acids-containing oligomers as external guide sequences: a methodology for inhibition of expression of antibiotic resistance genes. Biol Methods Protoc 2016; 1. [PMID: 27857983 PMCID: PMC5108630 DOI: 10.1093/biomethods/bpw001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
External guide sequences (EGSs) are short antisense oligoribonucleotides that elicit RNase P-mediated cleavage of a target mRNA, which results in inhibition of gene expression. EGS technology is used to inhibit expression of a wide variety of genes, a strategy that may lead to development of novel treatments of numerous diseases, including multidrug-resistant bacterial and viral infections. Successful development of EGS technology depends on finding nucleotide analogs that resist degradation by nucleases present in biological fluids and the environment but still elicit RNase P-mediated degradation when forming a duplex with a target mRNA. Previous results suggested that locked nucleic acids (LNA)/DNA chimeric oligomers have these properties. LNA are now considered the first generation of compounds collectively known as bridged nucleic acids (BNAs) – modified ribonucleotides that contain a bridge at the 2ʹ,4ʹ-position of the ribose. LNA and the second-generation BNA, known as BNANC, differ in the chemical nature of the bridge. Chimeric oligomers containing LNA or BNANC and deoxynucleotide monomers in different configurations are nuclease resistant and could be excellent EGS compounds. However, not all configurations may be equally active as EGSs. RNase P cleavage assays comparing LNA/DNA and BNANC/DNA chimeric oligonucleotides that share identical nucleotide sequence but with different configurations were carried out using as target the amikacin resistance aac(6ʹ)-Ib mRNA. LNA/DNA gapmers with 5 and 3/4 LNA residues at the 5ʹ- and 3ʹ-ends, respectively, were the most efficient EGSs while all BNANC/DNA gapmers showed very poor activity. When the most efficient LNA/DNA gapmer was covalently bound to a cell-penetrating peptide, the hybrid compound conserved the EGS activity as determined by RNase P cleavage assays and reduced the levels of resistance to amikacin when added to Acinetobacter baumannii cells in culture, an indication of cellular uptake and biological activity.
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Affiliation(s)
- Alexis Jackson
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA
| | - Saumya Jani
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA
| | - Carol Davies Sala
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA; Fundación Instituto Leloir, IIBBA-CONICET, and FCEyN, University of Buenos Aires, Argentina
| | - Alfonso J C Soler-Bistué
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA; Fundación Instituto Leloir, IIBBA-CONICET, and FCEyN, University of Buenos Aires, Argentina
| | - Angeles Zorreguieta
- Fundación Instituto Leloir, IIBBA-CONICET, and FCEyN, University of Buenos Aires, Argentina
| | - Marcelo E Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, USA
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135
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Wagner S, Sommer R, Hinsberger S, Lu C, Hartmann RW, Empting M, Titz A. Novel Strategies for the Treatment of Pseudomonas aeruginosa Infections. J Med Chem 2016; 59:5929-69. [DOI: 10.1021/acs.jmedchem.5b01698] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Stefanie Wagner
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Roman Sommer
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Stefan Hinsberger
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Cenbin Lu
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Rolf W. Hartmann
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Martin Empting
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Alexander Titz
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
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136
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Vinothkumar K, Kumar GN, Bhardwaj AK. Characterization of Vibrio fluvialis qnrVC5 Gene in Native and Heterologous Hosts: Synergy of qnrVC5 with other Determinants in Conferring Quinolone Resistance. Front Microbiol 2016; 7:146. [PMID: 26913027 PMCID: PMC4753295 DOI: 10.3389/fmicb.2016.00146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 01/26/2016] [Indexed: 12/02/2022] Open
Abstract
Resistance of various pathogens toward quinolones has emerged as a serious threat to combat infections. Analysis of plethora of genes and resistance mechanisms associated with quinolone resistance reveals chromosome-borne and transferable determinants. qnr genes have been found to be responsible for transferable quinolone resistance. In the present work, a new allele qnrVC5 earlier reported in Vibrio fluvialis from this laboratory was characterized in detail for its sequence, genetic context and propensity to decrease the susceptibility for quinolones. The study has revealed persistence of qnrVC5 in clinical isolates of V. fluvialis from Kolkata region through the years 2002–2006. qnrVC5 existed in the form of a gene cassette with the open reading frame being flanked by an upstream promoter and a downstream V. cholerae repeat region suggestive of its superintegron origin. Sequence analysis of different qnrVC alleles showed that qnrVC5 was closely related to qnrVC2 and qnrVC4 and these alleles were associated with V. cholerae repeats. In contrast, qnrVC1, qnrVC3, and qnrVC6 belonging to another group were associated with V. parahaemolyticus repeats. The gene manifested its activity in native V. fluvialis host as well as in Escherichia coli transformants harboring it by elevating the MIC toward various quinolones by twofold to eightfold. In combination with other quinolone resistance factors such as topoisomerase mutations and aac(6’)-Ib-cr gene, qnrVC5 gene product contributed toward higher quinolone resistance displayed by V. fluvialis isolates. Silencing of the gene using antisense peptide nucleic acid sensitized the V. fluvialis parent isolates toward ciprofloxacin. Recombinant QnrVC5 vividly demonstrated its role in conferring quinolone resistance. qnrVC5 gene, its synergistic effect and global dissemination should be perceived as a menace for quinolone-based therapies.
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Affiliation(s)
- Kittappa Vinothkumar
- Molecular Biology of Diseases, Department of Human Health and Diseases, School of Biological Sciences and Biotechnology, Indian Institute of Advanced ResearchGandhinagar, India; Department of Bio-Chemistry, Faculty of Science, The Maharaja Sayajirao University of BarodaVadodara, India
| | - G N Kumar
- Department of Bio-Chemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda Vadodara, India
| | - Ashima K Bhardwaj
- Molecular Biology of Diseases, Department of Human Health and Diseases, School of Biological Sciences and Biotechnology, Indian Institute of Advanced Research Gandhinagar, India
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137
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Santos RS, Dakwar GR, Xiong R, Forier K, Remaut K, Stremersch S, Guimarães N, Fontenete S, Wengel J, Leite M, Figueiredo C, De Smedt SC, Braeckmans K, Azevedo NF. Effect of Native Gastric Mucus on in vivo Hybridization Therapies Directed at Helicobacter pylori. MOLECULAR THERAPY. NUCLEIC ACIDS 2015; 4:e269. [PMID: 26645765 PMCID: PMC5014538 DOI: 10.1038/mtna.2015.46] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/28/2015] [Indexed: 12/17/2022]
Abstract
Helicobacter pylori infects more than 50% of the worldwide population. It is mostly found deep in the gastric mucus lining of the stomach, being a major cause of peptic ulcers and gastric adenocarcinoma. To face the increasing resistance of H. pylori to antibiotics, antimicrobial nucleic acid mimics are a promising alternative. In particular, locked nucleic acids (LNA)/2'-OMethyl RNA (2'OMe) have shown to specifically target H. pylori, as evidenced by in situ hybridization. The success of in vivo hybridization depends on the ability of these nucleic acids to penetrate the major physical barriers-the highly viscoelastic gastric mucus and the bacterial cell envelope. We found that LNA/2'OMe is capable of diffusing rapidly through native, undiluted, gastric mucus isolated from porcine stomachs, without degradation. Moreover, although LNA/2'OMe hybridization was still successful without permeabilization and fixation of the bacteria, which is normally part of in vitro studies, the ability of LNA/2'OMe to efficiently hybridize with H. pylori was hampered by the presence of mucus. Future research should focus on developing nanocarriers that shield LNA/2'OMe from components in the gastric mucus, while remaining capable of diffusing through the mucus and delivering these nucleic acid mimics directly into the bacteria.
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Affiliation(s)
- Rita S Santos
- LEPABE, Department of Chemical Engineering, Faculty of Engineering of the University of Porto, Porto, Portugal
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
| | - George R Dakwar
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Ranhua Xiong
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Katrien Forier
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Katrien Remaut
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Stephan Stremersch
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Nuno Guimarães
- LEPABE, Department of Chemical Engineering, Faculty of Engineering of the University of Porto, Porto, Portugal
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
- Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Sílvia Fontenete
- LEPABE, Department of Chemical Engineering, Faculty of Engineering of the University of Porto, Porto, Portugal
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
- Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
- Abel Salazar Institute of Biomedical Sciences (ICBAS), University of Porto, Porto, Portugal
| | - Jesper Wengel
- Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Marina Leite
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
| | - Céu Figueiredo
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
- Department of Pathology and Oncology, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Stefaan C De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Kevin Braeckmans
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Nuno F Azevedo
- LEPABE, Department of Chemical Engineering, Faculty of Engineering of the University of Porto, Porto, Portugal
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138
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George R, Cavalcante R, Jr CC, Marques E, Waugh JB, Unlap MT. Use of siRNA molecular beacons to detect and attenuate mycobacterial infection in macrophages. World J Exp Med 2015; 5:164-181. [PMID: 26309818 PMCID: PMC4543811 DOI: 10.5493/wjem.v5.i3.164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/05/2015] [Accepted: 06/11/2015] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis is one of the leading infectious diseases plaguing mankind and is mediated by the facultative pathogen, Mycobacterium tuberculosis (MTB). Once the pathogen enters the body, it subverts the host immune defenses and thrives for extended periods of time within the host macrophages in the lung granulomas, a condition called latent tuberculosis (LTB). Persons with LTB are prone to reactivation of the disease when the body’s immunity is compromised. Currently there are no reliable and effective diagnosis and treatment options for LTB, which necessitates new research in this area. The mycobacterial proteins and genes mediating the adaptive responses inside the macrophage is largely yet to be determined. Recently, it has been shown that the mce operon genes are critical for host cell invasion by the mycobacterium and for establishing a persistent infection in both in vitro and in mouse models of tuberculosis. The YrbE and Mce proteins which are encoded by the MTB mce operons display high degrees of homology to the permeases and the surface binding protein of the ABC transports, respectively. Similarities in structure and cell surface location impute a role in cell invasion at cholesterol rich regions and immunomodulation. The mce4 operon is also thought to encode a cholesterol transport system that enables the mycobacterium to derive both energy and carbon from the host membrane lipids and possibly generating virulence mediating metabolites, thus enabling the bacteria in its long term survival within the granuloma. Various deletion mutation studies involving individual or whole mce operon genes have shown to be conferring varying degrees of attenuation of infectivity or at times hypervirulence to the host MTB, with the deletion of mce4A operon gene conferring the greatest degree of attenuation of virulence. Antisense technology using synthetic siRNAs has been used in knocking down genes in bacteria and over the years this has evolved into a powerful tool for elucidating the roles of various genes mediating infectivity and survival in mycobacteria. Molecular beacons are a newer class of antisense RNA tagged with a fluorophore/quencher pair and their use for in vivo detection and knockdown of mRNA is rapidly gaining popularity.
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139
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Canady TD, Telmer CA, Oyaghire SN, Armitage BA, Bruchez MP. In Vitro Reversible Translation Control Using γPNA Probes. J Am Chem Soc 2015; 137:10268-75. [PMID: 26241615 DOI: 10.1021/jacs.5b05351] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
On-demand regulation of gene expression in living cells is a central goal of chemical biology and antisense therapeutic development. While significant advances have allowed regulatory modulation through inserted genetic elements, on-demand control of the expression/translation state of a given native gene by complementary sequence interactions remains a technical challenge. Toward this objective, we demonstrate the reversible suppression of a luciferase gene in cell-free translation using Watson-Crick base pairing between the mRNA and a complementary γ-modified peptide nucleic acid (γPNA) sequence with a noncomplementary toehold. Exploiting the favorable thermodynamics of γPNA-γPNA interactions, the antisense sequence can be removed by hybridization of a second, fully complementary γPNA, through a strand displacement reaction, allowing translation to proceed. Complementary RNA is also shown to displace the bound antisense γPNA, opening up possibilities of in vivo regulation by native gene expression.
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Affiliation(s)
- Taylor D Canady
- †Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Cheryl A Telmer
- †Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Stanley N Oyaghire
- †Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Bruce A Armitage
- †Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Marcel P Bruchez
- †Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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140
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Park H, Yoon Y, Suk S, Lee JY, Lee Y. Effects of different target sites on antisense RNA-mediated regulation of gene expression. BMB Rep 2015; 47:619-24. [PMID: 24411463 PMCID: PMC4281340 DOI: 10.5483/bmbrep.2014.47.11.257] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Indexed: 11/20/2022] Open
Abstract
Antisense RNA is a type of noncoding RNA (ncRNA) that binds to complementary mRNA sequences and induces gene repression by inhibiting translation or degrading mRNA. Recently, several small ncRNAs (sRNAs) have been identified in Escherichia coli that act as antisense RNA mainly via base pairing with mRNA. The base pairing predominantly leads to gene repression, and in some cases, gene activation. In the current study, we examined how the location of target sites affects sRNA-mediated gene regulation. An efficient antisense RNA expression system was developed, and the effects of antisense RNAs on various target sites in a model mRNA were examined. The target sites of antisense RNAs suppressing gene expression were identified, not only in the translation initiation region (TIR) of mRNA, but also at the junction between the coding region and 3' untranslated region. Surprisingly, an antisense RNA recognizing the upstream region of TIR enhanced gene expression through increasing mRNA stability.
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Affiliation(s)
- Hongmarn Park
- Department of Chemistry, KAIST, Daejeon 305-701, Korea
| | | | - Shinae Suk
- Department of Chemistry, KAIST, Daejeon 305-701, Korea
| | - Ji Young Lee
- Department of Chemistry, KAIST, Daejeon 305-701, Korea
| | - Younghoon Lee
- Department of Chemistry, KAIST, Daejeon 305-701, Korea
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141
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Acyl carrier protein is a bacterial cytoplasmic target of cationic antimicrobial peptide LL-37. Biochem J 2015; 470:243-53. [PMID: 26188040 DOI: 10.1042/bj20150432] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/16/2015] [Indexed: 11/17/2022]
Abstract
In addition to membrane disruption, the cathelicidin antimicrobial peptide (AMP) LL-37 translocates through the bacterial inner membrane to target intracellular molecules. The present study aims to identify an alternate mechanism and a cytoplasmic target of LL-37 in Francisella. LL-37 binding proteins from Francisella novicida U112 bacterial lysates were precipitated by using biotinylated LL-37 (B-LL-37) and NeutrAvidin-agarose beads. Bound proteins were identified by LC-MS/MS, validated and characterized by bead pull-down assays and differential scanning fluorimetry (DSF). The cationic AMP (CAMP) LL-37 was able to interact with Francisella cytoplasmic acyl carrier protein (AcpP; FTN1340/FTT1376). Further study confirmed that LL-37 peptide could bind to AcpP and that the sheep cathelicidin SMAP-29 (Sheep Myeloid Antimicrobial Peptide 29) further increased LL-37 binding to AcpP, suggesting a synergistic effect of SMAP-29 on the binding. LL-37 could also bind to both AcpP of Escherichia coli and Bacillus anthracis, implying a mechanism of broad action of LL-37-AcpP binding. Overexpression of the acpP gene in F. novicida led to an increase in LL-37 susceptibility. LL-37 binding to AcpP changed the fatty acid composition profiles. Taken together, we identified a novel cytoplasmic target of LL-37 in Francisella, suggesting a mechanism of action of this peptide beyond membrane permeabilization. Our findings highlight a novel mechanism of antimicrobial activity of this peptide and document a previously unexplored target of α-helical CAMPs.
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142
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Inhibition of AAC(6')-Ib-mediated resistance to amikacin in Acinetobacter baumannii by an antisense peptide-conjugated 2',4'-bridged nucleic acid-NC-DNA hybrid oligomer. Antimicrob Agents Chemother 2015; 59:5798-803. [PMID: 26169414 DOI: 10.1128/aac.01304-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/08/2015] [Indexed: 01/08/2023] Open
Abstract
Multiresistant Acinetobacter baumannii, a common etiologic agent of severe nosocomial infections in compromised hosts, usually harbors aac(6')-Ib. This gene specifies resistance to amikacin and other aminoglycosides, seriously limiting the effectiveness of these antibiotics. An antisense oligodeoxynucleotide (ODN4) that binds to a duplicated sequence on the aac(6')-Ib mRNA, one of the copies overlapping the initiation codon, efficiently inhibited translation in vitro. An isosequential nuclease-resistant hybrid oligomer composed of 2',4'-bridged nucleic acid-NC (BNA(NC)) residues and deoxynucleotides (BNA(NC)-DNA) conjugated to the permeabilizing peptide (RXR)4XB ("X" and "B" stand for 6-aminohexanoic acid and β-alanine, respectively) (CPPBD4) inhibited translation in vitro at the same levels observed in testing ODN4. Furthermore, CPPBD4 in combination with amikacin inhibited growth of a clinical A. baumannii strain harboring aac(6')-Ib in liquid cultures, and when both compounds were used as combination therapy to treat infected Galleria mellonella organisms, survival was comparable to that seen with uninfected controls.
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143
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Boisguérin P, Deshayes S, Gait MJ, O'Donovan L, Godfrey C, Betts CA, Wood MJA, Lebleu B. Delivery of therapeutic oligonucleotides with cell penetrating peptides. Adv Drug Deliv Rev 2015; 87:52-67. [PMID: 25747758 PMCID: PMC7102600 DOI: 10.1016/j.addr.2015.02.008] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/23/2015] [Accepted: 02/25/2015] [Indexed: 12/15/2022]
Abstract
Oligonucleotide-based drugs have received considerable attention for their capacity to modulate gene expression very specifically and as a consequence they have found applications in the treatment of many human acquired or genetic diseases. Clinical translation has been often hampered by poor biodistribution, however. Cell-penetrating peptides (CPPs) appear as a possibility to increase the cellular delivery of non-permeant biomolecules such as nucleic acids. This review focuses on CPP-delivery of several classes of oligonucleotides (ONs), namely antisense oligonucleotides, splice switching oligonucleotides (SSOs) and siRNAs. Two main strategies have been used to transport ONs with CPPs: covalent conjugation (which is more appropriate for charge-neutral ON analogues) and non-covalent complexation (which has been used for siRNA delivery essentially). Chemical synthesis, mechanisms of cellular internalization and various applications will be reviewed. A comprehensive coverage of the enormous amount of published data was not possible. Instead, emphasis has been put on strategies that have proven to be effective in animal models of important human diseases and on examples taken from the authors' own expertise.
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Affiliation(s)
- Prisca Boisguérin
- Centre de Recherche de Biochimie Macromoléculaire, UMR 5237 CNRS, 1919 Route de Mende, 34293 Montpellier, France.
| | - Sébastien Deshayes
- Centre de Recherche de Biochimie Macromoléculaire, UMR 5237 CNRS, 1919 Route de Mende, 34293 Montpellier, France
| | - Michael J Gait
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Liz O'Donovan
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Caroline Godfrey
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford OX1 3QX, UK
| | - Corinne A Betts
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford OX1 3QX, UK
| | - Matthew J A Wood
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford OX1 3QX, UK
| | - Bernard Lebleu
- UMR 5235 CNRS, Université Montpellier 2, Place Eugene Bataillon, Montpellier 34095, France
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144
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Courtney CM, Chatterjee A. Sequence-Specific Peptide Nucleic Acid-Based Antisense Inhibitors of TEM-1 β-Lactamase and Mechanism of Adaptive Resistance. ACS Infect Dis 2015; 1:253-63. [PMID: 27622741 DOI: 10.1021/acsinfecdis.5b00042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recent surge of drug-resistant superbugs and shrinking antibiotic pipeline are serious challenges to global health. In particular, the emergence of β-lactamases has caused extensive resistance against the most frequently prescribed class of β-lactam antibiotics. Here, we develop novel synthetic peptide nucleic acid-based antisense inhibitors that target the start codon and ribosomal binding site of the TEM-1 β-lactamase transcript and act via translation inhibition mechanism. We show that these antisense inhibitors are capable of resensitizing drug-resistant Escherichia coli to β-lactam antibiotics exhibiting 10-fold reduction in the minimum inhibitory concentration (MIC). To study the mechanism of resistance, we adapted E. coli at MIC levels of the β-lactam/antisense inhibitor combination and observed a nonmutational, bet-hedging based adaptive antibiotic resistance response as evidenced by phenotypic heterogeneity as well as heterogeneous expression of key stress response genes. Our data show that both the development of new antimicrobials and an understanding of cellular response during the development of tolerance could aid in mitigating the impending antibiotic crisis.
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Affiliation(s)
- Colleen M. Courtney
- Department of Chemical and Biological Engineering and ‡BioFrontiers
Institute, 596 UCB, University of Colorado, Boulder, Colorado 80303, United States
| | - Anushree Chatterjee
- Department of Chemical and Biological Engineering and ‡BioFrontiers
Institute, 596 UCB, University of Colorado, Boulder, Colorado 80303, United States
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145
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Brun O, Elduque X, Pedroso E, Grandas A. On-Resin Conjugation of Diene-Polyamides and Maleimides via Diels-Alder Cycloaddition. J Org Chem 2015; 80:6093-101. [PMID: 25985351 DOI: 10.1021/acs.joc.5b00592] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The reaction between maleimides and resin-linked diene-polyamides allows the latter to be used in the preparation of conjugates. Conjugation takes place by reacting the insoluble, hydrophobic diene component either with water-soluble dienophiles or with dienophiles requiring mixtures of water and organic solvents. Experimental conditions can be adjusted to furnish the target conjugate in good yield with no need of adding large excesses of soluble reagent. In case protected maleimides are used, maleimide deprotection and Diels-Alder cycloaddition can be simultaneously carried out to render conjugates with different linking positions. On-resin conjugation is followed by an acidic treatment that removes the polyamide protecting groups with no harm to the cycloadduct, in contrast with the unreacted diene that is indeed degraded under these conditions. Cycloadducts incorporating suitable functional groups can undergo subsequent additional conjugation reactions in solution to furnish double conjugates.
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Affiliation(s)
- Omar Brun
- Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Xavier Elduque
- Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Enrique Pedroso
- Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Anna Grandas
- Departament de Química Orgànica, Facultat de Química and IBUB, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
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146
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Chaudhary AK, Na D, Lee EY. Rapid and high-throughput construction of microbial cell-factories with regulatory noncoding RNAs. Biotechnol Adv 2015; 33:914-30. [PMID: 26027891 DOI: 10.1016/j.biotechadv.2015.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/27/2015] [Accepted: 05/27/2015] [Indexed: 12/11/2022]
Abstract
Due to global crises such as pollution and depletion of fossil fuels, sustainable technologies based on microbial cell-factories have been garnering great interest as an alternative to chemical factories. The development of microbial cell-factories is imperative in cutting down the overall manufacturing cost. Thus, diverse metabolic engineering strategies and engineering tools have been established to obtain a preferred genotype and phenotype displaying superior productivity. However, these tools are limited to only a handful of genes with permanent modification of a genome and significant labor costs, and this is one of the bottlenecks associated with biofactory construction. Therefore, a groundbreaking rapid and high-throughput engineering tool is needed for efficient construction of microbial cell-factories. During the last decade, copious small noncoding RNAs (ncRNAs) have been discovered in bacteria. These are involved in substantial regulatory roles like transcriptional and post-transcriptional gene regulation by modulating mRNA elongation, stability, or translational efficiency. Because of their vulnerability, ncRNAs can be used as another layer of conditional control over gene expression without modifying chromosomal sequences, and hence would be a promising high-throughput tool for metabolic engineering. Here, we review successful design principles and applications of ncRNAs for high-throughput metabolic engineering or physiological studies of diverse industrially important microorganisms.
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Affiliation(s)
- Amit Kumar Chaudhary
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea
| | - Dokyun Na
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
| | - Eun Yeol Lee
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea.
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147
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Ma S, Schroeder B, Sun C, Loufakis DN, Cao Z, Sriranganathan N, Lu C. Electroporation-based delivery of cell-penetrating peptide conjugates of peptide nucleic acids for antisense inhibition of intracellular bacteria. Integr Biol (Camb) 2015; 6:973-8. [PMID: 25160797 DOI: 10.1039/c4ib00172a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cell penetrating peptides (CPPs) have been used for a myriad of cellular delivery applications and were recently explored for delivery of antisense agents such as peptide nucleic acids (PNAs) for bacterial inhibition. Although these molecular systems (i.e. CPP-PNAs) have shown ability to inhibit growth of bacterial cultures in vitro, they show limited effectiveness in killing encapsulated intracellular bacteria in mammalian cells such as macrophages, presumably due to difficulty involved in the endosomal escape of the reagents. In this report, we show that electroporation delivery dramatically increases the bioavailability of CPP-PNAs to kill Salmonella enterica serovar Typhimurium LT2 inside macrophages. Electroporation delivers the molecules without involving endocytosis and greatly increases the antisense effect. The decrease in the average number of Salmonella per macrophage under a 1200 V cm(-1) and 5 ms pulse was a factor of 9 higher than that without electroporation (in an experiment with a multiplicity of infection of 2 : 1). Our results suggest that electroporation is an effective approach for a wide range of applications involving CPP-based delivery. The microfluidic format will allow convenient functional screening and testing of PNA-based reagents for antisense applications.
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Affiliation(s)
- Sai Ma
- School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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148
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Reen FJ, Gutiérrez-Barranquero JA, Dobson ADW, Adams C, O’Gara F. Emerging concepts promising new horizons for marine biodiscovery and synthetic biology. Mar Drugs 2015; 13:2924-54. [PMID: 25984990 PMCID: PMC4446613 DOI: 10.3390/md13052924] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 04/22/2015] [Accepted: 04/28/2015] [Indexed: 12/23/2022] Open
Abstract
The vast oceans of the world, which comprise a huge variety of unique ecosystems, are emerging as a rich and relatively untapped source of novel bioactive compounds with invaluable biotechnological and pharmaceutical potential. Evidence accumulated over the last decade has revealed that the diversity of marine microorganisms is enormous with many thousands of bacterial species detected that were previously unknown. Associated with this diversity is the production of diverse repertoires of bioactive compounds ranging from peptides and enzymes to more complex secondary metabolites that have significant bioactivity and thus the potential to be exploited for innovative biotechnology. Here we review the discovery and functional potential of marine bioactive peptides such as lantibiotics, nanoantibiotics and peptidomimetics, which have received particular attention in recent years in light of their broad spectrum of bioactivity. The significance of marine peptides in cell-to-cell communication and how this may be exploited in the discovery of novel bioactivity is also explored. Finally, with the recent advances in bioinformatics and synthetic biology, it is becoming clear that the integration of these disciplines with genetic and biochemical characterization of the novel marine peptides, offers the most potential in the development of the next generation of societal solutions.
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Affiliation(s)
- F. Jerry Reen
- BIOMERIT Research Centre, School of Microbiology, University College Cork—National University of Ireland, Cork, Ireland; E-Mails: (F.J.R.); (J.A.G.-B.); (C.A.)
| | - José A. Gutiérrez-Barranquero
- BIOMERIT Research Centre, School of Microbiology, University College Cork—National University of Ireland, Cork, Ireland; E-Mails: (F.J.R.); (J.A.G.-B.); (C.A.)
| | - Alan D. W. Dobson
- School of Microbiology, University College Cork—National University of Ireland, Cork, Ireland; E-Mail:
| | - Claire Adams
- BIOMERIT Research Centre, School of Microbiology, University College Cork—National University of Ireland, Cork, Ireland; E-Mails: (F.J.R.); (J.A.G.-B.); (C.A.)
| | - Fergal O’Gara
- BIOMERIT Research Centre, School of Microbiology, University College Cork—National University of Ireland, Cork, Ireland; E-Mails: (F.J.R.); (J.A.G.-B.); (C.A.)
- School of Biomedical Sciences, Curtin University, Perth WA 6845, Australia
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149
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Watanabe T, Hoshida T, Sakyo J, Kishi M, Tanabe S, Matsuura J, Akiyama S, Nakata M, Tanabe Y, Suzuki AZ, Watanabe S, Furuta T. Synthesis of nucleobase-caged peptide nucleic acids having improved photochemical properties. Org Biomol Chem 2015; 12:5089-93. [PMID: 24921960 DOI: 10.1039/c4ob00418c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A nucleobase-caged peptide nucleic acid (PNA) having a (6-bromo-7-methoxycoumarin)-4-ylmethoxycarbonyl (Bmcmoc) caging group was newly synthesized. The Bmcmoc-caged PNAs were photolyzed to produce parent PNAs with a high photochemical efficiency. Introduction of a single Bmcmoc group was sufficient to suppress polymerase chain reaction (PCR) clamping activity and triplex invasion complex formation. Photo-mediated restoration of the PCR clamping activity was also demonstrated.
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Affiliation(s)
- Takayoshi Watanabe
- Department of Biomolecular Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
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150
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Soheili S, Ghafourian S, Sekawi Z, Neela VK, Sadeghifard N, Taherikalani M, Khosravi A, Ramli R, Hamat RA. The mazEF toxin-antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:2553-61. [PMID: 26005332 PMCID: PMC4428366 DOI: 10.2147/dddt.s77263] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The toxin–antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains.
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Affiliation(s)
- Sara Soheili
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Sobhan Ghafourian
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Zamberi Sekawi
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Vasantha Kumari Neela
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Nourkhoda Sadeghifard
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Morovat Taherikalani
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Afra Khosravi
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
| | - Ramliza Ramli
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaakob Latif, Bandar Tun Razak, Kuala Lumpur, Malaysia
| | - Rukman Awang Hamat
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health sciences, Universiti Putra Malaysia, Serdang, Malaysia
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