title: Glial Hsp70 protects K+ homeostasis in the Drosophila brain during repetitive anoxic depolarization.
abstract: Neural tissue is particularly vulnerable to metabolic stress and loss of ion homeostasis. Repetitive stress generally leads to more permanent dysfunction but the mechanisms underlying this progression are poorly understood. We investigated the effects of energetic compromise in Drosophila by targeting the Na(+)/K(+)-ATPase. Acute ouabain treatment of intact flies resulted in subsequent repetitive comas that led to death and were associated with transient loss of K(+) homeostasis in the brain. Heat shock pre-conditioned flies were resistant to ouabain treatment. To control the timing of repeated loss of ion homeostasis we subjected flies to repetitive anoxia while recording extracellular [K(+)] in the brain. We show that targeted expression of the chaperone protein Hsp70 in glial cells delays a permanent loss of ion homeostasis associated with repetitive anoxic stress and suggest that this is a useful model for investigating molecular mechanisms of neuroprotection.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada. gary.ab.armstrong@gmail.com
authors.forename: Gary A B
authors.initials: GA
authors.lastname: Armstrong
authors.forename: Chengfeng
authors.initials: C
authors.lastname: Xiao
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Krill
authors.forename: Laurent
authors.initials: L
authors.lastname: Seroude
authors.forename: Ken
authors.initials: K
authors.lastname: Dawson-Scully
authors.forename: R Meldrum
authors.initials: RM
authors.lastname: Robertson
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D003128:Coma / Q000378:metabolism / Q000473:pathology; D004331:Drosophila melanogaster / Q000187:drug effects / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018869:Heat-Shock Response; D006706:Homeostasis / Q000187:drug effects; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects*; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009584:Nitrogen / Q000494:pharmacology; D009928:Organ Specificity; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D010042:Ouabain; D009584:Nitrogen; D011188:Potassium