Infection and Drug Resistance (Jul 2020)
Antimicrobial Peptide AMP-17 Affects Candida albicans by Disrupting Its Cell Wall and Cell Membrane Integrity
Abstract
Huiling Ma,1,2 Xinyu Zhao,1 Longbing Yang,1 Peipei Su,1 Ping Fu,1,3 Jian Peng,1,3 Na Yang,4 Guo Guo1,3,4 1Key and Characteristic Laboratory of Modern Pathogen Biology, School of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, People’s Republic of China; 2Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Sanquan College of Xinxiang Medical University, Xinxiang 453003, People’s Republic of China; 3Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang 550025, People’s Republic of China; 4School of Food Science, Guizhou Medical University, Guiyang 550025, People’s Republic of ChinaCorrespondence: Guo Guo Tel +86 13765024379Email [email protected]: Candida albicans is associated with high mortality among immunocompromised patients. Resistance to and toxic side effects of antifungal drugs require the development of alternative antifungal agents. AMP-17 is a novel antimicrobial peptide derived from Musca domestica that exerts excellent antifungal effects against the Candida species. In this article, we discuss the potential mechanism of AMP-17 against C. albicans from the perspective of affecting the latter’s cell external structure.Methods: Recombinant AMP-17 was prepared by prokaryotic expression system, and its anti-C. albicans activity was detected by microdilution method. Microscopy and scanning electron microscopy were used to examine morphological changes in C. albicans. Cell wall-specific staining method was used to detect the change of cell wall integrity of C. albicans after AMP-17 treatment. AMP-17-induced damage to the C. albicans cell membrane was analyzed by fluorescent probes and glycerol assay kit. The expression of genes related to fungal cell wall and cell-membrane synthesis was detected by qRT-PCR.Results: Morphological observations showed that the growth of C. albicans was significantly inhibited in AMP-17-treated cells; the cells appeared aggregated and dissolved, with severe irregularities in shape. Furthermore, AMP-17 damaged the integrity of C. albicans cell walls. The cell wall integrity rate of AMP-17-treated cells was only 21.7% compared to untreated cells. Moreover, the change of membrane dynamics and permeability suggested that the cell membrane was disrupted by AMP-17 treatment. Genetic analysis showed that after AMP-17 treatment, the cell wall synthesis-related gene FKS2 of C. albicans was up-regulated 3.46-fold, while the cell membrane ergosterol synthesis-related genes ERG1, ERG5, ERG6, and MET6 were down-regulated 5.88-, 17.54-, 13.33-, and 7.14-fold, respectively.Conclusion: AMP-17 treatment disrupted the cell wall integrity and membrane structure of C. albicans and is likely a novel therapeutic option for prevention and control of C. albicans infections.Keywords: AMP-17, C. albicans, cell wall, membrane dynamics and permeability
