Protective role of trehalose during severe oxidative stress caused by hydrogen peroxide and the adaptive oxidative stress response in Candida albicans

• Published in: Microbiology (Society for General Microbiology) Vol. 148; no. 8; pp. 2599 - 2606
• Main Authors: Alvarez-Peral, Francisco J, Zaragoza, Oscar, Pedreno, Yolanda, Arguelles, Juan-Carlos
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.08.2002; Society for General Microbiology
• Subjects: Biological and medical sciences; Candida albicans; Candida albicans - drug effects; Candida albicans - genetics; Candida albicans - physiology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Fungal; Genes, Fungal; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Hydrogen Peroxide - pharmacology; Microbiology; Mycology; Oxidative Stress - physiology; tps1 gene; Trehalase - metabolism; Trehalose; Trehalose - physiology; Fungi; Candida albicans; Oxidative stress; Trehalose; Hydrogen; Adaptive response; Peroxides; Fungi Imperfecti; Viability; Thallophyta
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-148-8-2599

Area de Microbiologia, Facultad de Biologia, Universidad de Murcia, Campus de Espinardo, E-30071 Murcia, Spain 1 Instituto de Investigaciones Biomédicas del CSIC, Unidad de Bioquimica y Genética de Levaduras, 28029 Madrid, Spain 2 Author for correspondence: Juan-Carlos Argüelles. Tel: +34 968 36 71 31. Fax: +34 968 36 39 63. e-mail: arguelle{at}um.es The cellular response to the oxidative stress caused by hydrogen peroxide and its putative correlation with the stress protector trehalose was investigated in Candida albicans CAI.4 and the tps1 / tps1 double mutant, which is deficient in trehalose synthesis. When exponential wild-type blastoconidia were exposed to high concentrations of hydrogen peroxide, they displayed a high cell survival, accompanied by a marked rise of intracellular trehalose. The latter is due to a moderate activation of trehalose synthase and the concomitant inactivation of neutral trehalase. Identical challenge in the tps1 / tps1 double mutant severely reduced cell viability, a phenotype which was suppressed by overexpression of the TPS1 gene. Pretreatment of growing cultures from both strains with either a low, non-lethal concentration of H 2 O 2 (0·5 mM) or a preincubation at 37 °C, induced an adaptive response that protected cells from being killed by a subsequent exposure to oxidative stress. During these mild oxidative preincubations, trehalose was not induced in CAI.4 cells and remained undetectable in their tps1 / tps1 counterpart. Blastoconidia from the two strains exhibited a similar degree of cell protection during the adaptive response. The induction of trehalose accumulation by H 2 O 2 was not due to an increased expression of TPS1 mRNA. These results are consistent with a mainly protective role of trehalose in C. albicans during direct oxidative stress but not during acquired oxidative tolerance. Keywords: TPS1 , cell protector, oxidative stress, adaptive response, opportunistic yeast pathogen Abbreviations: ROS, reactive oxygen species; T-6P synthase, trehalose-6-phosphate synthase a Present address: Albert Einstein College of Medicine, Microbiology and Immunology. Golding Building, room 701, 1300 Morris Park Avenue, Bronx, NY 10461, USA