Cationic phosphorodiamidate morpholino oligomers efficiently prevent growth of Escherichia coli in vitro and in vivo
| Autor: | Matthew Dale Reeves, Dwight D. Weller, Brett L. Mellbye, Bruce L. Geller, Patrick L. Iversen, Candace E. Lovejoy, Jed N. Hassinger |
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| Rok vydání: | 2009 |
| Předmět: |
Microbiology (medical)
Gram-negative bacteria Morpholino Injections Subcutaneous Morpholines Peptide Microbial Sensitivity Tests Peritonitis medicine.disease_cause Morpholinos Mice In vivo Escherichia coli medicine Animals Humans Pharmacology (medical) Escherichia coli Infections Antibacterial agent Pharmacology chemistry.chemical_classification Mice Inbred BALB C biology biology.organism_classification Survival Analysis Molecular biology In vitro Anti-Bacterial Agents Blood Infectious Diseases chemistry Biochemistry Female lipids (amino acids peptides and proteins) Bacterial outer membrane |
| Zdroj: | Journal of Antimicrobial Chemotherapy. 65:98-106 |
| ISSN: | 1460-2091 0305-7453 |
| DOI: | 10.1093/jac/dkp392 |
| Popis: | Objectives Phosphorodiamidate morpholino oligomers (PMOs) are uncharged DNA analogues that can inhibit bacterial growth by a gene-specific, antisense mechanism. Attaching cationic peptides to PMOs enables efficient penetration through the Gram-negative outer membrane. We hypothesized that cationic groups attached directly to the PMO would obviate the need to attach peptides. Methods PMOs with identical 11-base sequence (AcpP) targeted to acpP (an essential gene) of Escherichia coli were synthesized with various numbers of either piperazine (Pip) or N-(6-guanidinohexanoyl)piperazine (Gux) coupled to the phosphorodiamidate linker. Peptide-PMO conjugates were made using the membrane-penetrating peptide (RXR)(4)XB (X is 6-aminohexanoic acid; B is beta-alanine). Results MICs (microM/mg/L) were measured using E. coli: 3 + Pip-AcpP, 160/653; 6 + Pip-AcpP, 160/673; 2 + Gux-AcpP, 20/88; 5 + Gux-AcpP, 10/49; 8 + Gux-AcpP, 10/56; 3 + Pip-AcpP-(RXR)(4)XB, 0.3/2; and 5 + Gux-AcpP-(RXR)(4)XB, 0.6/4. In cell-free protein synthesis reactions, all PMOs inhibited gene expression approximately the same. These results suggested that Pip-PMOs inefficiently penetrated the outer membrane. Indeed, the MICs of 3 + Pip-AcpP and 6 + Pip-AcpP were reduced to 0.6 and 2.5 microM (1.2 and 10.5 mg/L), respectively, using as indicator a strain with a 'leaky' outer membrane. In vivo, mice were infected intraperitoneally with E. coli. Intraperitoneal treatment with 50 mg/kg 3 + Pip-AcpP, 15 mg/kg 5 + Gux-AcpP or 0.5 mg/kg 3 + Pip-AcpP-(RXR)(4)XB, or subcutaneous treatment with 15 mg/kg 5 + Gux-AcpP or (RXR)(4)XB-AcpP reduced bacteria in blood and increased survival. Conclusions Cationic PMOs inhibited bacterial growth in vitro and in vivo, and Gux-PMOs were more effective than Pip-PMOs. However, neither was as effective as the equivalent PMO-peptide conjugates. Subcutaneous treatment showed that 5 + Gux-AcpP or (RXR)(4)XB-AcpP entered the circulatory system, reduced infection and increased survival. |
| Databáze: | OpenAIRE |
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