title: Therapeutic hypothermia achieves neuroprotection via a decrease in acetylcholine with a concurrent increase in carnitine in the neonatal hypoxia-ischemia.
abstract: Although therapeutic hypothermia is known to improve neurologic outcomes after perinatal cerebral hypoxia-ischemia, etiology remains unknown. To decipher the mechanisms whereby hypothermia regulates metabolic dynamics in different brain regions, we used a two-step approach: a metabolomics to target metabolic pathways responding to cooling, and a quantitative imaging mass spectrometry to reveal spatial alterations in targeted metabolites in the brain. Seven-day postnatal rats underwent the permanent ligation of the left common carotid artery followed by exposure to 8% O2 for 2.5 hours. The pups were returned to normoxic conditions at either 38 °C or 30 °C for 3 hours. The brain metabolic states were rapidly fixed using in situ freezing. The profiling of 107 metabolites showed that hypothermia diminishes the carbon biomass related to acetyl moieties, such as pyruvate and acetyl-CoA; conversely, it increases deacetylated metabolites, such as carnitine and choline. Quantitative imaging mass spectrometry demarcated that hypothermia diminishes the acetylcholine contents specifically in hippocampus and amygdala. Such decreases were associated with an inverse increase in carnitine in the same anatomic regions. These findings imply that hypothermia achieves its neuroprotective effects by mediating the cellular acetylation status through a coordinated suppression of acetyl-CoA, which resides in metabolic junctions of glycolysis, amino-acid catabolism, and ketolysis.
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takenouchi
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Precursory Research for Embryonic Science and Technology (PRESTO) Project, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sugiura
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Morikawa
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] MS Business Unit, Shimadzu Corporation, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Nagahata
authors.affiliation: Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Sugioka
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Precursory Research for Embryonic Science and Technology (PRESTO) Project, Tokyo, Japan.
authors.forename: Kurara
authors.initials: K
authors.lastname: Honda
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kubo
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Hishiki
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Matsuura
authors.affiliation: Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Hoshino
authors.affiliation: Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Suematsu
authors.affiliation: 1] Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan [2] JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Tokyo, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kajimura
mesh_terms: D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000109:Acetylcholine / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism; D000679:Amygdala / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000831:Animals, Newborn; D002331:Carnitine / Q000378:metabolism*; D006019:Glycolysis; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D008297:Male; D013058:Mass Spectrometry; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000596:Amino Acids; D000105:Acetyl Coenzyme A; D019289:Pyruvic Acid; D000109:Acetylcholine; D002331:Carnitine