BACKGROUND: Leishmaniasis is a group of neglected vector-borne diseases transmitted by phlebotomine sand flies. Leishmania parasites must overcome various defenses in the sand fly midgut, including the insects's immune response. Insect immunity is regulated by the ecdysone hormone, which binds to its nuclear receptor (EcR) and activates the transcription of genes involved in insect immunity. However, the role of ecdysone in sand fly immunity has never been studied. Phlebotomus perniciosus is a natural vector of Leishmania infantum; here, we manipulated its neuroendocrine system using azadirachtin (Aza), a natural compound known to affect ecdysone synthesis. METHODS: Phlebotomus perniciosus larvae and adult females were fed on food containing either Aza alone or Aza plus ecdysone, and the effects on mortality and ecdysis were evaluated. Genes related to ecdysone signaling and immunity were identified in P. perniciosus, and the expression of antimicrobial peptides (AMPs), EcR, the ecdysone-induced genes Eip74EF and Eip75B, and the transcription factor serpent were analyzed using quantitative polymerase chain reaction (PCR). RESULTS: Aza treatment inhibited molting of first-instar (L1) larvae to L2, with only 10% of larvae molting compared to 95% in the control group. Serpent and Eip74EF, attacin, defensin 1, and defensin 2 genes were downregulated by Aza treatment in larvae. Similarly, Aza-treated adult females also presented suppression of ecdysone signaling-related genes and the AMPs attacin and defensin 2. Notably, all gene repression caused by Aza was reversed by adding ecdysone concomitantly with Aza to the larval or female food, indicating that these genes are effective markers for ecdysone repression. CONCLUSIONS: These results highlight the critical role of ecdysone in regulating the development and immunity of P. perniciosus, which potentially could interfere with Leishmania infection.

• Klíčová slova
• Phlebotomus perniciosus, Antimicrobial peptides, Azadirachtin, Ecdysone,
• MeSH
• antimikrobiální peptidy genetika   farmakologie   MeSH
• ekdyson * MeSH
• hmyz - vektory účinky léků   genetika   parazitologie   imunologie   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• larva * účinky léků   imunologie   genetika   MeSH
• limoniny * farmakologie   MeSH
• Phlebotomus * účinky léků   genetika   parazitologie   imunologie   MeSH
• shazování tělního pokryvu účinky léků   MeSH
• signální transdukce * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antimikrobiální peptidy MeSH
• azadirachtin MeSH Prohlížeč
• ekdyson * MeSH
• hmyzí proteiny MeSH
• limoniny * MeSH

Despite ongoing research on antimicrobial peptides (AMPs) and cell-penetrating peptides (CPPs), their precise translocation mechanism remains elusive. This includes Buforin 2 (BF2), a well-known AMP, for which spontaneous translocation across the membrane has been proposed but a high barrier has been calculated. Here, we used computer simulations to investigate the effect of a nonequilibrium situation where the peptides are adsorbed on one side of the lipid bilayer, mimicking experimental conditions. We demonstrated that the asymmetric membrane adsorption of BF2 enhances its translocation across the lipid bilayer by lowering the energy barrier by tens of kJ mol-1. We showed that asymmetric membrane adsorption also reduced the free energy barrier of lipid flip-flop but remained unlikely even at BF2 surface saturation. These results provide insight into the driving forces behind membrane translocation of cell-penetrating peptides in nonequilibrium conditions, mimicking experiments.

• MeSH
• adsorpce MeSH
• antimikrobiální peptidy chemie   farmakologie   MeSH
• buněčná membrána metabolismus   chemie   MeSH
• kationické antimikrobiální peptidy chemie   farmakologie   metabolismus   MeSH
• lipidové dvojvrstvy * chemie   metabolismus   MeSH
• penetrační peptidy chemie   metabolismus   MeSH
• proteiny MeSH
• simulace molekulární dynamiky MeSH
• termodynamika MeSH
• terpeny chemie   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antimikrobiální peptidy MeSH
• buforin II MeSH Prohlížeč
• kationické antimikrobiální peptidy MeSH
• lipidové dvojvrstvy * MeSH
• penetrační peptidy MeSH
• proteiny MeSH
• terpeny MeSH

• Klíčová slova
• Antimicrobial peptides, Burn wounds, Cathelicidins, Immunomodulation,
• MeSH
• antimikrobiální peptidy farmakologie   terapeutické užití   MeSH
• infekce v ráně * farmakoterapie   MeSH
• lidé MeSH
• popálení * farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• Názvy látek
• antimikrobiální peptidy MeSH

Peptides that form transmembrane barrel-stave pores are potential alternative therapeutics for bacterial infections and cancer. However, their optimization for clinical translation is hampered by a lack of sequence-function understanding. Recently, we have de novo designed the first synthetic barrel-stave pore-forming antimicrobial peptide with an identified function of all residues. Here, we systematically mutate the peptide to improve pore-forming ability in anticipation of enhanced activity. Using computer simulations, supported by liposome leakage and atomic force microscopy experiments, we find that pore-forming ability, while critical, is not the limiting factor for improving activity in the submicromolar range. Affinity for bacterial and cancer cell membranes needs to be optimized simultaneously. Optimized peptides more effectively killed antibiotic-resistant ESKAPEE bacteria at submicromolar concentrations, showing low cytotoxicity to human cells and skin model. Peptides showed systemic anti-infective activity in a preclinical mouse model of Acinetobacter baumannii infection. We also demonstrate peptide optimization for pH-dependent antimicrobial and anticancer activity.

• MeSH
• Acinetobacter baumannii účinky léků   MeSH
• antibakteriální látky farmakologie   chemie   chemická syntéza   MeSH
• antimikrobiální peptidy chemie   farmakologie   chemická syntéza   MeSH
• antitumorózní látky * farmakologie   chemie   chemická syntéza   MeSH
• kationické antimikrobiální peptidy farmakologie   chemie   chemická syntéza   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• racionální návrh léčiv * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• antimikrobiální peptidy MeSH
• antitumorózní látky * MeSH
• kationické antimikrobiální peptidy MeSH

BACKGROUND: Antimicrobial resistance (AMR) is nowadays a major emerging challenge for public health worldwide. The over- and misuse of antibiotics, including those for cell culture, are promoting AMR while also encouraging the research and employment of alternative drugs. The addition of antibiotics to the cell media is strongly recommended in sperm preservation, being gentamicin the most used for boar semen. Because of its continued use, several bacterial strains present in boar semen have developed resistance to this antibiotic. Antimicrobial peptides and proteins (AMPPs) are promising candidates as alternative antibiotics because their mechanism of action is less likely to promote AMR. In the present study, we tested two AMPPs (lysozyme and nisin; 50 and 500 µg/mL) as possible substitutes of gentamicin for boar semen preservation up to 48 h of storage. RESULTS: We found that both AMPPs improved sperm plasma membrane and acrosome integrity during semen storage. The highest concentration tested for lysozyme also kept the remaining sperm parameters unaltered, at 48 h of semen storage, and reduced the bacterial load at comparable levels of the samples supplemented with gentamicin (p > 0.05). On the other hand, while nisin (500 µg/mL) reduced the total Enterobacteriaceae counts, it also decreased the rapid and progressive sperm population and the seminal oxidation-reduction potential (p < 0.05). CONCLUSIONS: The protective effect of lysozyme on sperm function together with its antimicrobial activity and inborn presence in body fluids, including semen and cervical mucus, makes this enzyme a promising antimicrobial agent for boar semen preservation.

• Klíčová slova
• Antimicrobial resistance, Boar semen, Gentamicin, Lysozyme, Nisin, Sperm function,
• MeSH
• akrozom účinky léků   MeSH
• antibakteriální látky * farmakologie   MeSH
• antimikrobiální peptidy farmakologie   MeSH
• buněčná membrána účinky léků   MeSH
• gentamiciny farmakologie   MeSH
• muramidasa * farmakologie   MeSH
• nisin * farmakologie   MeSH
• prasata MeSH
• sperma účinky léků   MeSH
• spermie účinky léků   MeSH
• uchování spermatu * veterinární   metody   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky * MeSH
• antimikrobiální peptidy MeSH
• gentamiciny MeSH
• muramidasa * MeSH
• nisin * MeSH