title: Reduced glutathione export during programmed cell death of Neurospora crassa.
abstract: In a previous study, we demonstrated that staurosporine (STS) induces programmed cell death (PCD) in the fungus Neurospora crassa and that glutathione has the capability of inhibiting both STS-induced reactive oxygen species (ROS) formation and cell death. Here, we further investigated the role of glutathione in STS-induced PCD in N. crassa and observed an efflux of reduced glutathione (GSH) together with a change in the cell internal redox state to a more oxidative environment. This event was also observed with another PCD inducer, phytosphingosine (PHS), although externally added GSH did not prevent PHS-induced PCD. The nature of ROS, detected under the experimental conditions at which GSH export occurred, is also different in the two systems, predominantly superoxide in the case of STS and hydrogen peroxide in the case of PHS. In both cases, GSH export preceded the alterations in the plasma membrane that lead to selective dye permeation. We conclude that glutathione export in the context of PCD is not exclusive of certain mammalian cells and can be extended to Fungi, being an early PCD event in N. crassa. In addition, STS and PHS induce different PCD pathways in this fungus and the role of GSH export in each of them is likely different.
authors.affiliation: IBMC: Instituto de Biologia Molecular e Celular, Rua do Campo Alegre 823, 4150-180 Porto, Portugal. afernand@ibmc.up.pt
authors.forename: Andreia S
authors.initials: AS
authors.lastname: Fernandes
authors.forename: Ana
authors.initials: A
authors.lastname: Castro
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Videira
mesh_terms: D017209:Apoptosis; D001693:Biological Transport, Active / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism*; D009492:Neurospora crassa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D017382:Reactive Oxygen Species; D005978:Glutathione; D019311:Staurosporine