Nejvíce citovaný článek - PubMed ID 19348784
Different modes of membrane permeabilization by two RTX toxins: HlyA from Escherichia coli and CyaA from Bordetella pertussis
Finding effective antibiotics against multi-resistant strains of bacteria has been a challenging race. Linker-Evolved-Group-Optimized-Lipophosphonoxins (LEGO-LPPOs) are small modular synthetic antibacterial compounds targeting the cytoplasmic membrane. Here we focused on understanding the reasons for the variable efficacy of selected LEGO-LPPOs (LEGO-1, LEGO-2, LEGO-3, and LEGO-4) differing in hydrophobic and linker module structure and length. LEGO-1-4 permeabilized cytoplasmic membrane of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli, LEGO-1 with the longest linker module being the most effective. Gram-positive bacteria were more sensitive to LEGO-LPPO action compared to Gram-negatives, which was manifested as a delayed membrane permeabilization, higher minimal inhibitory concentration and lower amount of LEGO-LPPO bound to the cells. Outer membrane permeability measurements and time-kill assay showed that presence of the intact outer membrane brought about reduced susceptibility of Gram-negatives. Using liposome leakage and in silico simulations, we showed that membranes with major content of phosphatidylethanolamine were more prone to LEGO-LPPO permeabilization. The proposed mechanism stems from an electrostatic repulsion between highly positively charged LEGO-1 molecules and positively charged amino groups of phosphatidylethanolamine which destabilizes the membrane. Collectively, these data suggest that LEGO-LPPO membrane activity is enhanced by presence of phosphatidylethanolamine but hindered by presence of intact outer membrane.
- MeSH
- antibakteriální látky * farmakologie chemie MeSH
- buněčná membrána metabolismus MeSH
- Escherichia coli metabolismus účinky léků MeSH
- fosfatidylethanolaminy * chemie metabolismus MeSH
- mikrobiální testy citlivosti * MeSH
- permeabilita buněčné membrány účinky léků MeSH
- Staphylococcus aureus účinky léků metabolismus MeSH
- vnější bakteriální membrána metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antibakteriální látky * MeSH
- fosfatidylethanolaminy * MeSH
- phosphatidylethanolamine MeSH Prohlížeč
Bordetellae, pathogenic to mammals, produce an immunomodulatory adenylate cyclase toxin-hemolysin (CyaA, ACT or AC-Hly) that enables them to overcome the innate immune defense of the host. CyaA subverts host phagocytic cells by an orchestrated action of its functional domains, where an extremely catalytically active adenylyl cyclase enzyme is delivered into phagocyte cytosol by a pore-forming repeat-in-toxin (RTX) cytolysin moiety. By targeting sentinel cells expressing the complement receptor 3, known as the CD11b/CD18 (αMβ₂) integrin, CyaA compromises the bactericidal functions of host phagocytes and supports infection of host airways by Bordetellae. Here, we review the state of knowledge on structural and functional aspects of CyaA toxin action, placing particular emphasis on signaling mechanisms by which the toxin-produced 3',5'-cyclic adenosine monophosphate (cAMP) subverts the physiology of phagocytic cells.
- Klíčová slova
- Bordetella, CD11b/CD18, adenylate cyclase toxin, cAMP, cell signaling, complement receptor 3, innate immunity, membrane pores, repeats-in-toxin, β2 integrins,
- MeSH
- adenylátcyklasový toxin chemie MeSH
- alveolární makrofágy cytologie MeSH
- AMP cyklický chemie MeSH
- Bordetella pertussis MeSH
- dendritické buňky cytologie MeSH
- fagocyty chemie MeSH
- kinasa Syk MeSH
- lidé MeSH
- makrofágový antigen 1 MeSH
- neutrofily cytologie MeSH
- proteinové domény MeSH
- signální transdukce * MeSH
- terciární struktura proteinů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- adenylátcyklasový toxin MeSH
- AMP cyklický MeSH
- kinasa Syk MeSH
- makrofágový antigen 1 MeSH
- SYK protein, human MeSH Prohlížeč
The structural properties of microfiber meshes made from poly(2-hydroxyethyl methacrylate) (PHEMA) were found to significantly depend on the chemical composition and subsequent cross-linking and nebulization processes. PHEMA microfibres showed promise as scaffolds for chondrocyte seeding and proliferation. Moreover, the peak liposome adhesion to PHEMA microfiber scaffolds observed in our study resulted in the development of a simple drug anchoring system. Attached foetal bovine serum-loaded liposomes significantly improved both chondrocyte adhesion and proliferation. In conclusion, fibrous scaffolds from PHEMA are promising materials for tissue engineering and, in combination with liposomes, can serve as a simple drug delivery tool.
- MeSH
- biokompatibilní materiály chemie MeSH
- buněčná adheze MeSH
- chondrocyty cytologie MeSH
- fluorescenční mikroskopie metody MeSH
- konfokální mikroskopie metody MeSH
- lékové transportní systémy MeSH
- liposomy chemie MeSH
- nosiče léků chemie MeSH
- polyhydroxyethylmethakrylát chemie MeSH
- polymery chemie MeSH
- proliferace buněk MeSH
- racionální návrh léčiv MeSH
- reagencia zkříženě vázaná chemie MeSH
- skot MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- liposomy MeSH
- nosiče léků MeSH
- polyhydroxyethylmethakrylát MeSH
- polymery MeSH
- reagencia zkříženě vázaná MeSH