title: The temperature dependence and involvement of mitochondria permeability transition and caspase activation in damage to organotypic hippocampal slices following in vitro ischemia.
abstract: The aggravating effect of hyperglycemia on ischemic brain injury can be mimicked in a model of in vitro ischemia (IVI) using murine hippocampal slice cultures. Using this model, we found that the damage in the CA1 region following IVI in the absence or presence of 40 mm glucose (hyperglycemia) is highly temperature dependent. Decreasing the temperature from 35 to 31 degrees C during IVI prevented cell death, whereas increasing the temperature by 2 degrees C markedly aggravated damage. As blockade of the mitochondrial permeability transition (MPT) is equally effective as hypothermia in preventing ischemic cell death in vivo, we investigated whether inhibition of MPT or of caspases was protective following IVI. In the absence of glucose, the MPT blockers cyclosporin A and MeIle4-CsA but not the immunosuppressive compound FK506 diminished cell death. In contrast, following hyperglycemic IVI, MPT blockade was ineffective. Also, the pan-caspase inhibitor Boc-Asp(OMe)fluoromethyl ketone did not decrease cell death in the CA1 region following IVI or hyperglycemic IVI. We conclude that cell death in the CA1 region of organotypic murine hippocampal slices following IVI is highly temperature dependent and involves MPT. In contrast, cell death following hyperglycemic IVI, although completely prevented by hypothermia, is not mediated by mechanisms that involve MPT or caspase activation.
authors.affiliation: Laboratory for Experimental Brain Research, Lund University, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Rytter
authors.forename: Carla M P
authors.initials: CM
authors.lastname: Cardoso
authors.forename: Petra
authors.initials: P
authors.lastname: Johansson
authors.forename: Tobias
authors.initials: T
authors.lastname: Cronberg
authors.forename: Magnus J
authors.initials: MJ
authors.lastname: Hansson
authors.forename: Gustav
authors.initials: G
authors.lastname: Mattiasson
authors.forename: Eskil
authors.initials: E
authors.lastname: Elmér
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Wieloch
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002545:Brain Ischemia / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D016923:Cell Death; D003952:Diagnostic Imaging / Q000379:methods; D004347:Drug Interactions; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods; D006624:Hippocampus / Q000378:metabolism* / Q000503:physiopathology*; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology*; D008954:Models, Biological; D009924:Organ Culture Techniques; D010539:Permeability / Q000187:drug effects; D013696:Temperature; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D002118:Calcium