Caspofungin Kills Candida albicans by Causing both Cellular Apoptosis and Necrosis
Open Access
- 1 January 2013
- journal article
- research article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 57 (1), 326-332
- https://doi.org/10.1128/aac.01366-12
Abstract
Caspofungin exerts candidacidal activity by inhibiting cell wall (1,3)-β- d -glucan synthesis. We investigated the physiologic mechanisms of caspofungin-induced Candida albicans cell death. Apoptosis (programmed cell death) and necrosis were studied after C. albicans SC5314 cells were exposed to caspofungin at 0.06, 0.125, and 0.5 μg/ml (0.5×, 1×, and 4× the MIC, respectively) for 3 h. Caspofungin at 0.125 and 0.5 μg/ml reduced cellular viability by >50%, as measured by colony counts and methylene blue exclusion. Apoptosis and necrosis were demonstrated by annexin V and propidium iodide staining for phosphatidylserine externalization and loss of membrane integrity, respectively. At all concentrations of caspofungin, 20 to 25% and 5 to 7% of C. albicans cells exhibited early apoptosis and late apoptosis/necrosis, respectively ( P value was not significant [NS]). Necrosis, on the other hand, was significantly greater at 0.125 (43%) and 0.5 (48%) μg/ml than at 0.06 μg/ml (26%) ( P values of 0.003 and 0.003, respectively). The induction of apoptosis at concentrations less than or equal to the MIC was corroborated by dihydrorhodamine 123 (DHR-123) and dihydroethidium (DHE) staining (reactive oxygen species production), JC-1 staining (mitochondrial membrane potential dissipation), and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and 4′,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining (DNA damage and nuclear fragmentation). Moreover, electron microscopy of cells exposed to 0.125 μg/ml of caspofungin showed hallmark apoptotic features like chromatin margination and condensation and nuclear blebs. Apoptosis was associated with metacaspase 1 activation, as demonstrated by D2R staining. Caspofungin exerts activity against C. albicans by directly killing cells (resulting in necrosis) and causing others to undergo programmed cell death (apoptosis). Apoptosis is initiated at subinhibitory concentrations, suggesting that strategies to target this process may augment the benefits of antifungal agents.Keywords
This publication has 40 references indexed in Scilit:
- Bcl-xL Retrotranslocates Bax from the Mitochondria into the CytosolCell, 2011
- Lack of Trehalose Accelerates H2O2-Induced Candida albicans Apoptosis through Regulating Ca2+ Signaling Pathway and Caspase ActivityPLOS ONE, 2011
- Farnesol-Induced Apoptosis in Candida albicansAntimicrobial Agents and Chemotherapy, 2009
- Pseudomonas aeruginosa - Candida albicans Interactions: Localization and Fungal Toxicity of a Phenazine DerivativeApplied and Environmental Microbiology, 2009
- Human Lactoferrin Induces Apoptosis-Like Cell Death inCandida albicans: Critical Role of K+-Channel-Mediated K+EffluxAntimicrobial Agents and Chemotherapy, 2008
- Stimulation of Chitin Synthesis Rescues Candida albicans from EchinocandinsPLoS Pathogens, 2008
- Diallyl disulphide depletes glutathione in Candida albicans: oxidative stress‐mediated cell death studied by two‐photon microscopyYeast, 2007
- The PKC, HOG and Ca2+ signalling pathways co‐ordinately regulate chitin synthesis in Candida albicansMolecular Microbiology, 2007
- Human β-Defensins Kill Candida albicans in an Energy-Dependent and Salt-Sensitive Manner without Causing Membrane DisruptionAntimicrobial Agents and Chemotherapy, 2007
- ApoptosisImmunology Today, 1993