Authors: Antonella Lupetti¹; Carlo P. J. M. Brouwer²; Heleen E. C. Dogterom-Ballering¹; Sonia Senesi³; Mario Campa³; Jaap T. van Dissel¹; Peter H. Nibbering¹

Source: Journal of Antimicrobial Chemotherapy, Volume 54, Number 3, 1 September 2004 , pp. 603-608(6)

Publisher: Oxford University Press

Abstract:

Objectives: Earlier studies showed that mitochondrial damage is a hallmark of the candidacidal activity of an N-terminal peptide of human lactoferrin, further referred to as hLF(1–11). Since uptake of Ca²⁺ by mitochondria may be essential for their activation, the aim of this study was to define the role of Ca²⁺ in killing of Candida albicans by the hLF(1–11) peptide.

Methods: The effect of compounds interfering with Ca²⁺ homeostasis on the hLF(1–11)-induced candidacidal activity, changes in mitochondrial membrane potential, and reactive oxygen species production were evaluated using a killing assay, rhodamine 123 staining, and 2,7-dichlorofluorescein diacetate, respectively. The increase in cellular Ca²⁺ content was measured using ⁴⁵Ca²⁺.

Results: Our results revealed that Ruthenium Red, which inhibits the mitochondrial Ca²⁺-uniporter and the voltage-sensitive Ca²⁺ release from internal stores, blocked (P<0.05) the hLF(1–11)-induced candidacidal activity as well as changes in the membrane potential of mitochondria, and reactive oxygen species production. Oxalate, which precipitates Ca²⁺ in intracellular organelles, decreased (P<0.05) the peptide-induced changes in the membrane potential of mitochondria, reactive oxygen species production, and candidacidal activity. Furthermore, the Ca²⁺ ionophore ionomycin combined with high CaCl<inf>2</inf> concentrations enhanced the hLF(1–11)-induced candidacidal activity. Moreover, hLF(1–11) caused an influx of Ca²⁺ from the extracellular medium into C. albicans reaching a three-fold increase at 2 h, whereas no increase was found in unexposed cells. In agreement, the Ca²⁺-chelator EGTA blocked the peptide-induced candidacidal activity.

Conclusions: Ca²⁺ release from intracellular stores, probably through subsequent mitochondrial Ca²⁺ uptake, is essential for the hLF(1–11)-induced candidacidal activity.

Keywords: lactoferrin peptide; mitochondrial Ca

Document Type: Research article

DOI: http://dx.doi.org/10.1093/jac/dkh385

Affiliations: 1: Department of Infectious Diseases, C5-P, Leiden University Medical Center (LUMC), P.O. Box 9600, 2300 RC Leiden; 2: AM-Pharma, Rumpsterweg, 6, 3981 AK Bunnik, The Netherlands; 3: Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università degli Studi di Pisa, Via S. Zeno, 35–39, 56127 Pisa, Italy

Publication date: 2004-09-01

More about this publication?

• The Journal of Antimicrobial Chemotherapy is among the foremost international journals in antimicrobial research. Our readership includes representatives of academia, industry and health services, and includes those who are influential in formulary decisions.

Related content

• In this: publication
• By this: publisher
• In this Subject: Pharmacology
• By this author: Antonella Lupetti ;  Carlo P. J. M. Brouwer ;  Heleen E. C. Dogterom-Ballering ;  Sonia Senesi ;  Mario Campa ;  Jaap T. van Dissel ;  Peter H. Nibbering

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers