title: HIF-1α regulation in mammalian hibernators: role of non-coding RNA in HIF-1α control during torpor in ground squirrels and bats.
abstract: A potential role for non-coding RNAs, miR-106b and antisense hypoxia inducible transcription factor-1 (HIF-1α), in HIF-1α regulation during mammalian hibernation was investigated in two species, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) and the little brown bat (Myotis lucifugus). Both species showed differential regulation of HIF-1α during hibernation. HIF-1α protein levels increased significantly in skeletal muscle of both species when animals entered torpor, as well as in bat liver. HIF-1α mRNA levels correlated with the protein increase in bat skeletal muscle and liver but not in squirrel skeletal muscle. Antisense HIF-1α transcripts were identified in skeletal muscle of both hibernators. The expression of antisense HIF-1α was reduced in skeletal muscle of torpid bats compared with euthermic controls, suggesting that release of inhibition by the antisense RNA contributes to regulating HIF-1α translation in this tissue during torpor. The expression of miR-106b, a microRNA associated with HIF-1α regulation, also decreased during torpor in both skeletal muscle and liver of bats and in ground squirrel skeletal muscle. These data present the first evidence that non-coding RNA provides novel post-transcriptional mechanisms of HIF-1α regulation when hibernators descend into deep cold torpor, and also demonstrate that these mechanisms are conserved in two divergent mammalian orders (Rodentia and Chiroptera).
authors.affiliation: Department of Biology, Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Maistrovski
authors.forename: Kyle K
authors.initials: KK
authors.lastname: Biggar
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Storey
mesh_terms: D000818:Animals; D001483:Base Sequence; D002685:Chiroptera / Q000502:physiology*; D006605:Hibernation / Q000502:physiology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D022661:RNA, Untranslated / Q000378:metabolism*; D012589:Sciuridae / Q000502:physiology*
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D035683:MicroRNAs; D022661:RNA, Untranslated