title: Tissue-type plasminogen activator mediates neuronal detection and adaptation to metabolic stress.
abstract: Adenosine monophosphate-activated protein kinase (AMPK) is an energy sensor that regulates cellular adaptation to metabolic stress. Tissue-type plasminogen activator (tPA) is a serine proteinase found in the intravascular space, where its main role is as thrombolytic enzyme, and in neurons, where its function is less well understood. Here, we report that glucose deprivation induces the mobilization and package of neuronal tPA into presynaptic vesicles. Mass spectrometry and immunohistochemical studies show that the release of this tPA in the synaptic space induces AMPK activation in the postsynaptic terminal, and an AMPK-mediated increase in neuronal uptake of glucose and neuronal adenosine 5'(tetrahydrogen triphosphate; ATP) synthesis. This effect is independent of tPA's proteolytic properties, and instead requires the presence of functional N-methyl-D-aspartate receptors (NMDARs). In agreement with these observations, positron emission tomography (PET) studies and biochemical analysis with synaptoneurosomes indicate that the intravenous administration of recombinant tPA (rtPA) after transient middle cerebral artery occlusion (tMCAO) induces AMPK activation in the synaptic space and NMDAR-mediated glucose uptake in the ischemic brain. These data indicate that the release of neuronal tPA or treatment with rtPA activate a cell signaling pathway in the synaptic space that promotes the detection and adaptation to metabolic stress.
authors.affiliation: Department of Neurology, Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Wu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Nicholson
authors.forename: Woldeab B
authors.initials: WB
authors.lastname: Haile
authors.forename: Enrique
authors.initials: E
authors.lastname: Torre
authors.forename: Jie
authors.initials: J
authors.lastname: An
authors.forename: Changhua
authors.initials: C
authors.lastname: Chen
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Lee
authors.forename: Duc M
authors.initials: DM
authors.lastname: Duong
authors.forename: Eric B
authors.initials: EB
authors.lastname: Dammer
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Seyfried
authors.forename: Frank C
authors.initials: FC
authors.lastname: Tong
authors.forename: John R
authors.initials: JR
authors.lastname: Votaw
authors.forename: Manuel
authors.initials: M
authors.lastname: Yepes
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005947:Glucose / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000255:Adenosine Triphosphate; D055372:AMP-Activated Protein Kinases; D010959:Tissue Plasminogen Activator; D005947:Glucose; D010100:Oxygen