Chien-Hua Huang1, Chih-Yen Chiang2, Ren-How Pen3, Min-Shan Tsai4, Huei-Wen Chen5, Chiung-Yuan Hsu6, Tzung-Dau Wang7, Matthew Huei-Ming Ma8, Shyr-Chyr Chen9, Wen-Jone Chen10. 1. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: chhuang730@ntu.edu.tw. 2. Division of Cardiology, Department of Internal Medicine, Cardinal Tien Hospital Yonghe Branch, New Taipei City, Taiwan. Electronic address: chiang5184@pchome.com.tw. 3. Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan. Electronic address: motorbird21@yahoo.com.tw. 4. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: mshanmshan@gmail.com. 5. Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: shwchen@ntu.edu.tw. 6. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: dtemer01@gmail.com. 7. Department of Internal Medicine (Cardiology), College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: tdwang@ntu.edu.tw. 8. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: mhma@ntu.edu.tw. 9. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: scchen@ntu.edu.tw. 10. Department of Emergency Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Internal Medicine, Lotung Poh-Ai Hospital, Yilan County, Taiwan. Electronic address: wjchen1955@ntu.edu.tw.
Abstract
BACKGROUND: Haemorrhagic shock after traumatic injury carries a high mortality. Therapeutic hypothermia has been widely used in critical illness to improve the outcome in haemorrhagic shock by activation of cardiac pro-survival signalling pathways. However, the role played by the mitochondria in the cardioprotective effects of therapeutic hypothermia remains unclear. We investigated the effects of therapeutic hypothermia on mitochondrial function and integrity after haemorrhagic shock using an in vitro ischaemia-reperfusion model. METHODS: H9c2 cardiomyocytes received a simulated ischaemic reperfusion injury under normothermic (37 °C) and hypothermic (31 °C) conditions. The cardiomyocytes were treated with hypoxic condition for 18 h in serum-free, glucose-free culture medium at pH 6.9 and then shifted to re-oxygenation status for 6h in serum-containing cell culture medium at pH 7.4. Cellular survival, mitochondrial integrity, energy metabolism and calcium homeostasis were studied. RESULTS: Hypothermia treatment lessened cell death (15.0 ± 12.7 vs. 31.9 ± 11.8%, P=0.025) and preserved mitochondrial number (81.3 ± 17.4 vs. 45.2 ± 6.6, P=0.03) against simulated ischaemic reperfusion injury. Hypothermia treatment ameliorated calcium overload in the intracellular (1.5 ± 0.2 vs. 9.5 ± 2.8, P<0.001) and intra-mitochondrial (1.0 ± 0.3 vs. 1.6 ± 0.3, P=0.014) compartments against the injury. Mitochondrial integrity was more preserved by hypothermia treatment (50.1 ± 26.6 vs. 14.8 ± 13.0%, P<0.01) after the injury. Mitochondrial ATP concentrations were maintained with hypothermia treatment after injury (16.7 ± 9.5 vs. 6.1 ± 5.1 μM, P<0.01). CONCLUSIONS: Hypothermia treatment at 31 °C can ameliorate cardiomyocyte damage caused by simulated ischaemic reperfusion injuries. Mitochondrial calcium homeostasis, energy metabolism, and membrane integrity are preserved and play critical roles during therapeutic hypothermia treatment.
BACKGROUND:Haemorrhagic shock after traumatic injury carries a high mortality. Therapeutic hypothermia has been widely used in critical illness to improve the outcome in haemorrhagic shock by activation of cardiac pro-survival signalling pathways. However, the role played by the mitochondria in the cardioprotective effects of therapeutic hypothermia remains unclear. We investigated the effects of therapeutic hypothermia on mitochondrial function and integrity after haemorrhagic shock using an in vitro ischaemia-reperfusion model. METHODS: H9c2 cardiomyocytes received a simulated ischaemic reperfusion injury under normothermic (37 °C) and hypothermic (31 °C) conditions. The cardiomyocytes were treated with hypoxic condition for 18 h in serum-free, glucose-free culture medium at pH 6.9 and then shifted to re-oxygenation status for 6h in serum-containing cell culture medium at pH 7.4. Cellular survival, mitochondrial integrity, energy metabolism and calcium homeostasis were studied. RESULTS:Hypothermia treatment lessened cell death (15.0 ± 12.7 vs. 31.9 ± 11.8%, P=0.025) and preserved mitochondrial number (81.3 ± 17.4 vs. 45.2 ± 6.6, P=0.03) against simulated ischaemic reperfusion injury. Hypothermia treatment ameliorated calcium overload in the intracellular (1.5 ± 0.2 vs. 9.5 ± 2.8, P<0.001) and intra-mitochondrial (1.0 ± 0.3 vs. 1.6 ± 0.3, P=0.014) compartments against the injury. Mitochondrial integrity was more preserved by hypothermia treatment (50.1 ± 26.6 vs. 14.8 ± 13.0%, P<0.01) after the injury. Mitochondrial ATP concentrations were maintained with hypothermia treatment after injury (16.7 ± 9.5 vs. 6.1 ± 5.1 μM, P<0.01). CONCLUSIONS:Hypothermia treatment at 31 °C can ameliorate cardiomyocyte damage caused by simulated ischaemic reperfusion injuries. Mitochondrial calcium homeostasis, energy metabolism, and membrane integrity are preserved and play critical roles during therapeutic hypothermia treatment.
Authors: Derek J Hausenloy; Jose A Barrabes; Hans Erik Bøtker; Sean M Davidson; Fabio Di Lisa; James Downey; Thomas Engstrom; Péter Ferdinandy; Hector A Carbrera-Fuentes; Gerd Heusch; Borja Ibanez; Efstathios K Iliodromitis; Javier Inserte; Robert Jennings; Neena Kalia; Rajesh Kharbanda; Sandrine Lecour; Michael Marber; Tetsuji Miura; Michel Ovize; Miguel A Perez-Pinzon; Hans Michael Piper; Karin Przyklenk; Michael Rahbek Schmidt; Andrew Redington; Marisol Ruiz-Meana; Gemma Vilahur; Jakob Vinten-Johansen; Derek M Yellon; David Garcia-Dorado Journal: Basic Res Cardiol Date: 2016-10-20 Impact factor: 17.165