Design and studies of multiple mechanism of anti-Candida activity of a new potent Trp-rich peptide dendrimers

• Published in: European journal of medicinal chemistry Vol. 105; pp. 106 - 119
• Main Authors: Zielińska, Paulina, Staniszewska, Monika, Bondaryk, Małgorzata, Koronkiewicz, Mirosława, Urbańczyk-Lipkowska, Zofia
• Format: Journal Article
• Language: English
• Published: ISSY-LES-MOULINEAUX Elsevier Masson SAS 13.11.2015; Elsevier
• Subjects: Antifungal Agents - chemical synthesis; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Antimicrobial Cationic Peptides - chemistry; Apoptosis; Apoptosis - drug effects; Aspartic protease; Biofilm; Caco-2 Cells; Candida; Candida albicans - cytology; Candida albicans - drug effects; Candida albicans - growth & development; Cell Wall - drug effects; Chemistry, Medicinal; Dendrimers - chemical synthesis; Dendrimers - chemistry; Dendrimers - pharmacology; Dose-Response Relationship, Drug; Drug Design; Humans; Inhibitor; Life Sciences & Biomedicine; Microbial Sensitivity Tests; Molecular Structure; Necrosis; Pharmacology & Pharmacy; Science & Technology; Structure-Activity Relationship; Synthesis; Trp-rich dendrimers; Tryptophan - chemistry; Trp-rich dendrimers; Synthesis; Candida; Biofilm; Aspartic protease; Inhibitor; Necrosis; Apoptosis; TRYPTOPHAN; AMPHOTERICIN-B; ANTIMICROBIAL PEPTIDES; PROTEINASES; VIRULENCE; IDENTIFICATION; CANDIDA-ALBICANS; SECRETED ASPARTIC PROTEASES; ANTIFUNGAL
• DOI: 10.1016/j.ejmech.2015.10.013
• ISSN: 0223-5234

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. 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. 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. 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. Candida albicans exposed to peptide dendrimer 14 at MIC concentration of 16 μg/mL. The cell wall staining with calcofluor white revealed that blastoconidial cells (arrowheads) and hyphae (arrow) were swollen and abnormally elongated. [Display omitted] •Trp-rich dendrimeric peptide causes apoptosis-like cell death in Candida spp.•Dendrimer 14 affects morphogenesis and biofilm viability of Candida.•14 causes the membrane damage at fungicidal concentration (16 μg/mL).