title: Hypothermia protects H9c2 cardiomyocytes from H2O2 induced apoptosis.
abstract: The purpose of our study was to investigate underlying basic mechanisms of hypothermia-induced cardioprotection during oxidative stress in a cardiomyocyte cell culture model. For hypothermic treatment we cooled H9c2 cardiomyocytes to 20°C, maintained 20min at 20°C during which short-term oxidative damage was inflicted with 2mM H(2)O(2,) followed by rewarming to 37°C. Later on, we analyzed lactate dehydrogenase (LDH), caspase-3 cleavage, reactive oxygen species (ROS), mitochondrial activity, intracellular ATP production, cytoprotective signal molecules as well as DNA damage. Hypothermia decreased H(2)O(2) damage in cardiomyocytes as demonstrated in a lower LDH release, less caspase-3 cleavage and less M30 CytoDeath staining. After rewarming H(2)O(2) damaged cells demonstrated a significantly higher reduction rate of intracellular ROS compared to normothermic H(2)O(2) damaged cardiomyocytes(.) This was in line with a significantly greater mitochondrial dehydrogenase activity and higher intracellular ATP content in cooled and rewarmed cells. Moreover, hypothermia preserved cell viability by up-regulation of the anti-apoptotic protein Bcl-2 and a reduction of p53 phosphorylation. DNA damage, proven by PARP-1 cleavage and H2AX phosphorylation, was significantly reduced by hypothermia. In conclusion, we could demonstrate that hypothermia protects cardiomyocytes during oxidative stress by preventing apoptosis via inhibiting mitochondrial dysfunction and DNA damage.
authors.affiliation: Department of Pediatric Cardiology, Charité-Universitätsmedizin Berlin, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Diestel
authors.forename: Cornelia
authors.initials: C
authors.lastname: Drescher
authors.forename: Oliver
authors.initials: O
authors.lastname: Miera
authors.forename: Felix
authors.initials: F
authors.lastname: Berger
authors.forename: Katharina Rose Luise
authors.initials: KR
authors.lastname: Schmitt
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects; D006657:Histones / Q000187:drug effects / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007036:Hypothermia, Induced; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D011065:Poly(ADP-ribose) Polymerases / Q000187:drug effects / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate; D053148:Caspase 3; D006657:Histones; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D011065:Poly(ADP-ribose) Polymerases; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; C475961:gamma-H2AX protein, mouse