title: Human lactoferrin triggers a mitochondrial- and caspase-dependent regulated cell death in Saccharomyces cerevisiae.
abstract: We have previously shown that the antifungal activity of human lactoferrin (hLf) against Candida albicans relies on its ability to induce cell death associated with apoptotic markers. To gain a deeper understanding of the mechanisms underlying hLf-induced apoptosis, we characterized this cell death process in the well-established Saccharomyces cerevisiae model. Our results indicate that hLf induces cell death in S. cerevisiae in a manner that requires energy and de novo protein synthesis. Cell death is associated with nuclear chromatin condensation, preservation of plasma membrane integrity, and is Yca1p metacaspase-dependent. Lactoferrin also caused mitochondrial dysfunction associated with ROS accumulation and release of cytochrome c. Pre-incubation with oligomycin, an oxidative phosphorylation inhibitor, increased resistance to hLf and, accordingly, mutants deficient in the F1F0-ATP synthase complex were more resistant to death induced by hLf. This indicates that mitochondrial energetic metabolism plays a key role in the killing effect of hLf, though a direct role of F1F0-ATP synthase cannot be precluded. Overexpression of the anti-apoptotic protein Bcl-xL or pre-incubation with N-acetyl cysteine reduced the intracellular level of ROS and increased resistance to hLf, confirming a ROS-mediated mitochondrial cell death process. Mitochondrial involvement was further reinforced by the higher resistance of cells lacking mitochondrial DNA, or other known yeast mitochondrial apoptosis regulators, such as, Aif1p, Cyc3p and Aac1/2/3p. This study provides new insights into a detailed understanding at the molecular level of hLf-induced apoptosis, which may allow the design of new strategies to overcome the emergence of resistance of clinically relevant fungi to conventional antifungals.
authors.affiliation: Laboratorio de Microbiología Oral, Escuela de Estomatología, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.|Departamento de Biología Funcional (Microbiología), Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Acosta-Zaldívar
authors.affiliation: Laboratorio de Microbiología Oral, Escuela de Estomatología, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Andrés
authors.affiliation: CBMA - Centro de Biologia Molecular e Ambiental, Departamento de Biologia, Universidade do Minho, Campus Gualtar, Braga, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Rego
authors.affiliation: CBMA - Centro de Biologia Molecular e Ambiental, Departamento de Biologia, Universidade do Minho, Campus Gualtar, Braga, Portugal.
authors.forename: C S
authors.initials: CS
authors.lastname: Pereira
authors.affiliation: Laboratorio de Microbiología Oral, Escuela de Estomatología, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.|Departamento de Biología Funcional (Microbiología), Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Fierro
authors.affiliation: CBMA - Centro de Biologia Molecular e Ambiental, Departamento de Biologia, Universidade do Minho, Campus Gualtar, Braga, Portugal. mcortereal@bio.uminho.pt.
authors.forename: M
authors.initials: M
authors.lastname: Côrte-Real
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D017209:Apoptosis; D006801:Humans; D007781:Lactoferrin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; C490098:LTF protein, human; D007781:Lactoferrin
keywords: Caspase; Lactoferrin; Mitochondria; Regulated cell death; Yeast