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Pseudomonas aeruginosais an opportunistic pathogen that forms antibiotic-resistant biofilms, which facilitate chronic infections in immunocompromised hosts. We have previously shown thatP. aeruginosasecretes outer-membrane vesicles that deliver a small RNA to human airway epithelial cells (AECs), in which it suppresses the innate immune response. Here, we demonstrate that interdomain communication through small RNA–containing membrane vesicles is bidirectional and that microRNAs (miRNAs) in extracellular vesicles (EVs) secreted by human AECs regulate protein expression, antibiotic sensitivity, and biofilm formation byP. aeruginosa. Specifically, human EVs deliver miRNA let-7b-5p toP. aeruginosa, which systematically decreases the abundance of proteins essential for biofilm formation, including PpkA and ClpV1-3, and increases the ability of beta-lactam antibiotics to reduce biofilm formation by targeting the beta-lactamase AmpC. Let-7b-5p is bioinformatically predicted to target not only PpkA, ClpV1, and AmpC inP. aeruginosabut also the corresponding orthologs inBurkholderia cenocepacia, another notorious opportunistic lung pathogen, suggesting that the ability of let-7b-5p to reduce biofilm formation and increase beta-lactam sensitivity is not limited toP. aeruginosa. Here, we provide direct evidence for transfer of miRNAs in EVs secreted by eukaryotic cells to a prokaryote, resulting in subsequent phenotypic alterations in the prokaryote as a result of this interdomain communication. Since let-7–family miRNAs are in clinical trials to reduce inflammation and because chronicP. aeruginosalung infections are associated with a hyperinflammatory state, treatment with let-7b-5p and a beta-lactam antibiotic in nanoparticles or EVs may benefit patients with antibiotic-resistantP. aeruginosainfections.
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Rational inhibitor design for Pseudomonas aeruginosa salicylate adenylation enzyme PchD
Abstract Pseudomonas aeruginosais an increasingly antibiotic-resistant pathogen that causes severe lung infections, burn wound infections, and diabetic foot infections.P. aeruginosaproduces the siderophore pyochelin through the use of a non-ribosomal peptide synthetase (NRPS) biosynthetic pathway. Targeting members of siderophore NRPS proteins is one avenue currently under investigation for the development of new antibiotics against antibiotic-resistant organisms. Here, the crystal structure of the pyochelin adenylation domain PchD is reported. The structure was solved to 2.11 Å when co-crystallized with the adenylation inhibitor 5′-O-(N-salicylsulfamoyl)adenosine (salicyl-AMS) and to 1.69 Å with a modified version of salicyl-AMS designed to target an active site cysteine (4-cyano-salicyl-AMS). In the structures, PchD adopts the adenylation conformation, similar to that reported for AB3403 fromAcinetobacter baumannii. Graphical abstract
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- Award ID(s):
- 2041047
- PAR ID:
- 10371203
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- JBIC Journal of Biological Inorganic Chemistry
- Volume:
- 27
- Issue:
- 6
- ISSN:
- 1432-1327
- Page Range / eLocation ID:
- p. 541-551
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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