title: Induction of Antioxidant and Heat Shock Protein Responses During Torpor in the Gray Mouse Lemur, Microcebus murinus.
abstract: A natural tolerance of various environmental stresses is typically supported by various cytoprotective mechanisms that protect macromolecules and promote extended viability. Among these are antioxidant defenses that help to limit damage from reactive oxygen species and chaperones that help to minimize protein misfolding or unfolding under stress conditions. To understand the molecular mechanisms that act to protect cells during primate torpor, the present study characterizes antioxidant and heat shock protein (HSP) responses in various organs of control (aroused) and torpid gray mouse lemurs, Microcebus murinus. Protein expression of HSP70 and HSP90α was elevated to 1.26 and 1.49 fold, respectively, in brown adipose tissue during torpor as compared with control animals, whereas HSP60 in liver of torpid animals was 1.15 fold of that in control (P<0.05). Among antioxidant enzymes, protein levels of thioredoxin 1 were elevated to 2.19 fold in white adipose tissue during torpor, whereas Cu-Zn superoxide dismutase 1 levels rose to 1.1 fold in skeletal muscle (P<0.05). Additionally, total antioxidant capacity was increased to 1.6 fold in liver during torpor (P<0.05), while remaining unchanged in the five other tissues. Overall, our data suggest that antioxidant and HSP responses are modified in a tissue-specific manner during daily torpor in gray mouse lemurs. Furthermore, our data also show that cytoprotective strategies employed during primate torpor are distinct from the strategies in rodent hibernation as reported in previous studies.
authors.affiliation: Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Department of Biology, Genetics Institute, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Cheng-Wei
authors.initials: CW
authors.lastname: Wu
authors.affiliation: Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Biochemistry Department, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada.
authors.forename: Kyle K
authors.initials: KK
authors.lastname: Biggar
authors.affiliation: Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Chemistry and Chemical Engineering Department, Royal Military College Of Canada, Kingston, ON K7K 7B4, Canada.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada; Department of Surgery & Center for Engineering in Medicine, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA.
authors.forename: Shannon N
authors.initials: SN
authors.lastname: Tessier
authors.affiliation: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy 91800, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Pifferi
authors.affiliation: UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy 91800, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Perret
authors.affiliation: Institute of Biochemistry & Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada. Electronic address: kenneth_storey@carleton.ca.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Storey
mesh_terms: D002001:Adipose Tissue, Brown / Q000378:metabolism; D052436:Adipose Tissue, White / Q000378:metabolism; D000818:Animals; D018834:Chaperonin 60 / Q000378:metabolism; D016565:Cheirogaleidae / Q000378:metabolism*; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006605:Hibernation / Q000502:physiology; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D064348:Torpor
chemical_list: D018834:Chaperonin 60; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D013482:Superoxide Dismutase
keywords: Antioxidant capacity; Heat shock proteins; Primate hypometabolism; Stress response