title: AMP-activated protein kinase (AMPK)-induced preconditioning in primary cortical neurons involves activation of MCL-1.
abstract: Neuronal preconditioning is a phenomenon where a previous exposure to a sub-lethal stress stimulus increases the resistance of neurons towards a second, normally lethal stress stimulus. Activation of the energy stress sensor, AMP-activated protein kinase (AMPK) has been shown to contribute to the protective effects of ischaemic and mitochondrial uncoupling-induced preconditioning in neurons, however, the molecular basis of AMPK-mediated preconditioning has been less well characterized. We investigated the effect of AMPK preconditioning using 5-aminoimidazole-4-carboxamide riboside (AICAR) in a model of NMDA-mediated excitotoxic injury in primary mouse cortical neurons. Activation of AMPK with low concentrations of AICAR (0.1 mM for 2 h) induced a transient increase in AMPK phosphorylation, protecting neurons against NMDA-induced excitotoxicity. Analysing potential targets of AMPK activation, demonstrated a marked increase in mRNA expression and protein levels of the anti-apoptotic BCL-2 family protein myeloid cell leukaemia sequence 1 (MCL-1) in AICAR-preconditioned neurons. Interestingly, over-expression of MCL-1 protected neurons against NMDA-induced excitotoxicity while MCL-1 gene silencing abolished the effect of AICAR preconditioning. Monitored intracellular Ca²⁺ levels during NMDA excitation revealed that MCL-1 over-expressing neurons exhibited improved bioenergetics and markedly reduced Ca²⁺ elevations, suggesting a potential mechanism through which MCL-1 confers neuroprotection. This study identifies MCL-1 as a key effector of AMPK-induced preconditioning in neurons.
authors.affiliation: Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Ujval
authors.initials: U
authors.lastname: Anilkumar
authors.forename: Petronela
authors.initials: P
authors.lastname: Weisová
authors.forename: Heiko
authors.initials: H
authors.lastname: Düssmann
authors.forename: Caoimhín G
authors.initials: CG
authors.lastname: Concannon
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: König
authors.forename: Jochen H M
authors.initials: JH
authors.lastname: Prehn
mesh_terms: D000091162:AMP-Activated Protein Kinase Kinases; D000222:Adaptation, Physiological / Q000502:physiology*; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D007004:Hypoglycemic Agents / Q000494:pharmacology; D051379:Mice; D018613:Microscopy, Confocal; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D016202:N-Methylaspartate / Q000633:toxicity; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012265:Ribonucleotides / Q000494:pharmacology; D013312:Stress, Physiological / Q000502:physiology
chemical_list: D007004:Hypoglycemic Agents; C579094:Mcl1 protein, mouse; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D012265:Ribonucleotides; D000620:Aminoimidazole Carboxamide; D016202:N-Methylaspartate; D011494:Protein Kinases; D000091162:AMP-Activated Protein Kinase Kinases; C031143:AICA ribonucleotide