title: The cellular resistance against oxidative stress (H2O2) is independent of neutral trehalase (Ntc1p) activity in Candida albicans.
abstract: The protective role of trehalose against oxidative stress caused by hydrogen peroxide in Candida albicans has been investigated in the homozygous mutant ntc1Delta/ntc1Delta, disrupted in the NTC1 gene, which encodes the neutral (cytosolic) trehalase (Ntc1p). After a severe oxidative exposure (50 mM H(2)O(2)), both parental (CAI-4) and ntc1Delta/ntc1Delta exponential-phase cells stored large amounts of intracellular trehalose. In turn, the degree of cell survival was roughly equivalent in both strains, although slightly higher in ntc1Delta/ntc1Delta cultures. The mechanism of 'adaptive tolerance' was functional in the two strains. Thus, a gently oxidative pretreatment (5 mM H(2)O(2)) increased the recovery of cellular viability when it was followed by a severe challenge (50 mM H(2)O(2)); this phenomenon was accompanied by a significant elevation of the endogenous trehalose content. Oxidative stress also induced specific activation of the antioxidant enzymes catalase and glutathione reductase upon gentle oxidative treatment (5 mM H(2)O(2)), whereas superoxide dismutase activity was only activated upon prolonged exposure. Taken together, these results strongly suggest that in C. albicans neutral trehalase activity does not play an essential role in the protective response against oxidative stress. They also suggest that a diminished Ntc1p activity might favour the growth of C. albicans cells subjected to a strong oxidative exposure.
authors.affiliation: Area de Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Pendreño
authors.forename: Y
authors.initials: Y
authors.lastname: Pedreño
authors.forename: Pilar
authors.initials: P
authors.lastname: González-Párraga
authors.forename: P
authors.initials: P
authors.lastname: González-Párraga
authors.forename: Sergio
authors.initials: S
authors.lastname: Conesa
authors.forename: S
authors.initials: S
authors.lastname: Conesa
authors.forename: María
authors.initials: M
authors.lastname: Martínez-Esparza
authors.forename: M
authors.initials: M
authors.lastname: Martínez-Esparza
authors.forename: Ana
authors.initials: A
authors.lastname: Aguinaga
authors.forename: A
authors.initials: A
authors.lastname: Aguinaga
authors.forename: José A
authors.initials: JA
authors.lastname: Hernández
authors.forename: J A
authors.initials: JA
authors.lastname: Hernández
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Argüelles
mesh_terms: D002176:Candida albicans / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D003470:Culture Media; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D018384:Oxidative Stress; D014198:Trehalase / Q000235:genetics / Q000378:metabolism*; D014199:Trehalose / Q000378:metabolism
chemical_list: D003470:Culture Media; D014199:Trehalose; D006861:Hydrogen Peroxide; D014198:Trehalase