title: Design and studies of multiple mechanism of anti-Candida activity of a new potent Trp-rich peptide dendrimers.
abstract: OBJECTIVE
  Eight peptide dendrimers were designed as structural mimics of natural cationic amphiphilic peptides with antifungal activity and evaluated for their anti-Candida potential against the wild type strains and mutants.
  
  
  METHODS
  Dendrimer 14 containing four Trp residues and dodecyl tail and a slightly smaller dendrimer 9 decorated with four N-methylated Trp that displayed 100 and 99.7% of growth inhibition at 16 μg/mL respectively, were selected for evaluation against the Candida albicans mutants with disabled biosynthesis of aspartic proteases responsible for host tissue colonization and morphogenesis during biofilm formation (sessile model). Flow cytometry method was employed to detect apoptotic cells with membrane alterations (phosphatidylserine translocation), and differentiation of apoptotic from necrotic cells was also performed. Simultaneous staining of cell surface phosphatidylserine with Annexin-V-Fluorescein and necrotic cells with propidium iodide was conducted.
  
  
  RESULTS
  14 at 16 μg/mL caused C. albicans cells to undergo cellular apoptosis but its increasing concentrations induced necrosis. 14 influenced C. albicans biofilm viability as well as hyphal and cell wall morphology. Confocal microscopy and cell wall staining with calcofluor white revealed that in epithelial model the cell surface structure was perturbed at MIC of peptide dendrimer. It appears that tryptophan or 1-methyltryptophan groups displayed at the surface and positive charges hidden in the dendrimer tree along with hydrocarbon tail located at C-terminus are important for the anti-Candida activity since dendrimers containing tryptamine at C-terminus showed only a moderate activity.
  
  
  CONCLUSIONS
  Our results suggest that membranolytic dendrimer 14, targeting cellular apoptotic pathway and impairing the cell wall formation in mature biofilm, may be a potential multifunctional antifungal lead compound for the control of C. albicans infections.
authors.affiliation: Institute of Organic Chemistry PAS, 01-224, Warsaw, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Zielińska
authors.affiliation: National Institute of Public Health - National Institute of Hygiene, 00-791, Warsaw, Poland. Electronic address: mstaniszewska@pzh.gov.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Staniszewska
authors.affiliation: National Institute of Public Health - National Institute of Hygiene, 00-791, Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Bondaryk
authors.affiliation: National Medicines Institute, Warsaw, 00-725, Poland.
authors.forename: Mirosława
authors.initials: M
authors.lastname: Koronkiewicz
authors.affiliation: Institute of Organic Chemistry PAS, 01-224, Warsaw, Poland. Electronic address: zofia.lipkowska@icho.edu.pl.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Urbańczyk-Lipkowska
mesh_terms: D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D017209:Apoptosis / Q000187:drug effects; D018938:Caco-2 Cells; D002176:Candida albicans / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D002473:Cell Wall / Q000187:drug effects; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D006801:Humans; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D050091:Dendrimers; D014364:Tryptophan
keywords: Apoptosis; Aspartic protease; Biofilm; Candida; Inhibitor; Necrosis; Synthesis; Trp-rich dendrimers