OBJECTIVE: The aim of this study was to explore the molecular mechanisms involved in late preconditioning-induced cell protection in endothelial cells. METHODS AND RESULTS: Preconditioning (PC) was induced by exposing bovine aortic endothelial cells (BAECs) to 3 cycles of 15 minutes of hypoxia followed by 15 minutes of reoxygenation. A 12-hour period of hypoxia induced cell death in 60% of BAECs (48+/-5% apoptosis, 12+/-4% necrosis). Early and late PC decreased hypoxia-induced apoptotic (25+/-5% and 28+/-4%, respectively) and necrotic (6+/-3%, and 8+/-2%, respectively) cell death. Consistently, hypoxia-induced caspase-3 cleavage was reduced by PC. Pretreatment with H89 (protein kinase A [PKA] inhibitor), LY294002 (phosphatidyl-inositol-3-kinase [PI3K] inhibitor), and N-acetyl-cysteine (antioxidant) abrogated late PC-induced cell protection, whereas inhibition of protein kinase C by Go6983, and of nitric oxide synthesis by L-NAME,1400W and bovine eNOS siRNA did not. In addition, in early and late PC, PKA physically interacted with the phosphorylated form of Akt, suggesting that PKA is required for Akt phosphorylation. Expression of PKA and Akt dominant negative mutants inhibited ischemic late PC-induced protection, indicating that these kinases play a key role in late PC-mediated cell protection. CONCLUSIONS: Late ischemic PC protects BAECs against hypoxia through PKA- and PI3K-dependent activation of Akt.
OBJECTIVE: The aim of this study was to explore the molecular mechanisms involved in late preconditioning-induced cell protection in endothelial cells. METHODS AND RESULTS: Preconditioning (PC) was induced by exposing bovine aortic endothelial cells (BAECs) to 3 cycles of 15 minutes of hypoxia followed by 15 minutes of reoxygenation. A 12-hour period of hypoxia induced cell death in 60% of BAECs (48+/-5% apoptosis, 12+/-4% necrosis). Early and late PC decreased hypoxia-induced apoptotic (25+/-5% and 28+/-4%, respectively) and necrotic (6+/-3%, and 8+/-2%, respectively) cell death. Consistently, hypoxia-induced caspase-3 cleavage was reduced by PC. Pretreatment with H89 (protein kinase A [PKA] inhibitor), LY294002 (phosphatidyl-inositol-3-kinase [PI3K] inhibitor), and N-acetyl-cysteine (antioxidant) abrogated late PC-induced cell protection, whereas inhibition of protein kinase C by Go6983, and of nitric oxide synthesis by L-NAME,1400W and bovine eNOS siRNA did not. In addition, in early and late PC, PKA physically interacted with the phosphorylated form of Akt, suggesting that PKA is required for Akt phosphorylation. Expression of PKA and Akt dominant negative mutants inhibited ischemic late PC-induced protection, indicating that these kinases play a key role in late PC-mediated cell protection. CONCLUSIONS: Late ischemic PC protects BAECs against hypoxia through PKA- and PI3K-dependent activation of Akt.
Authors: Changjun Yang; M A Hassan Talukder; Saradhadevi Varadharaj; Murugesan Velayutham; Jay L Zweier Journal: Cardiovasc Res Date: 2012-09-12 Impact factor: 10.787
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Authors: Anastasia Georgiadi; Valeria Lopez-Salazar; Rabih El- Merahbi; Rhoda Anane Karikari; Xiaochuan Ma; André Mourão; Katarina Klepac; Lea Bühler; Ana Jimena Alfaro; Isabell Kaczmarek; Adam Linford; Madeleen Bosma; Olga Shilkova; Olli Ritvos; Nobuhiro Nakamura; Shigehisa Hirose; Maximilian Lassi; Raffaele Teperino; Juliano Machado; Marcel Scheideler; Arne Dietrich; Arie Geerlof; Annette Feuchtinger; Andreas Blutke; Katrin Fischer; Timo Dirk Müller; Katharina Kessler; Torsten Schöneberg; Doreen Thor; Silke Hornemann; Michael Kruse; Peter Nawroth; Olga Pivovarova-Ramich; Andreas Friedrich Hermann Pfeiffer; Michael Sattler; Matthias Blüher; Stephan Herzig Journal: Nat Commun Date: 2021-05-20 Impact factor: 14.919