title: Characterization of apoptosis signal transduction pathways in HL-5 cardiomyocytes exposed to ischemia/reperfusion oxidative stress model.
abstract: During ischemia/reperfusion (I/R), cardiomyocytes are exposed to sudden lack of nutrients and successively to radical oxygen species (ROS). In the present study, we used the HL-5 cardiac atrial myocyte cell line exposed to serum/glucose depletion added or not in H(2)O(2) to mimic ROS during ischemia, then replaced in their standard culture medium to simulate reperfusion. We investigated the effects of serum/glucose depletion combined or not to ROS exposure on AKT and MAP kinases activation to address the role of each event with respect to apoptosis. We demonstrate that serum/glucose depletion per se did not induce apoptosis when compared to ROS exposure. In particular, ROS recruited p38MAPK and JNK pathways. SB202190 preventing p38MAPK activity, partially protected HL-5 from apoptosis while blocking JNK, thanks to JNKI, further enhanced apoptosis. Blocking phosphatidylinositol (PI) 3-kinase with LY294002 or ERKs with U0126 was without consequence on apoptosis. Finally, BCL-2 and BCL-X(L/S) expression levels were analyzed in cells exposed to 1 h ischemia followed by 12-h reperfusion in the presence or not of SB202190; BCL-2, but not BCL-X(L/S), expression was decreased in ROS treated cells but SB202190 failed to restore BCL-2 level. Our data suggest that p38MAPK activation primarily mediates ROS-induced apoptosis while concomitant JNK activation would represent a scavenger pathway for cells trying to escape apoptosis.
authors.affiliation: Laboratory of Molecular Medicine, Department of Internal Medicine, Rome, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Cicconi
authors.forename: Natascia
authors.initials: N
authors.lastname: Ventura
authors.forename: Donatella
authors.initials: D
authors.lastname: Pastore
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonini
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Nardo
authors.forename: Renato
authors.initials: R
authors.lastname: Lauro
authors.forename: Lionel N J L
authors.initials: LN
authors.lastname: Marlier
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D006861:Hydrogen Peroxide / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017202:Myocardial Ischemia / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D051020:bcl-X Protein; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D016877:Oxidants; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; D048051:p38 Mitogen-Activated Protein Kinases; C494812:Bcl2l1 protein, mouse