Effects of mild hypothermia on expression of NF-E2-related factor 2 and heme-oxygenase-1 in cerebral cortex and hippocampus after cardiopulmonary resuscitation in rats

Document Type : Original Article

Authors

Department of Emergency, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China

Abstract

Objective(s): The aim of this study was to investigate the effects of mild hypothermia on expression of NF-E2-related factor 2 (Nrf2) and heme-oxygenase-1 (HO-1) of rat cerebral cortex and hippocampus after cardiopulmonary resuscitation and further investigate the possible mechanism of action.
Material and Methods:To copy an asphyxia heart arrest model, Sprague Dawley rats were randomly divided into normothermia group, mild hypothermia group before restoration of spontaneous circulation (ROSC), and mild hypothermia group after ROSC. Body temperature in normothermia group was maintained at 37.5-39℃, while in mild hypothermia group maintained at 32-34 °C by surface cooling with the ice pack. Each group then divided into three subgroups: 15 min, 30 min, and 60 min. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the expression of Nrf2 and HO-1 mRNA in cerebral cortex and hippocampus. Hematoxylin-eosin (H&E) staining was performed to observe histological changes. Immunohistochemistry was performed to detect the expression of Nrf2 and HO-1 protein expression.
Results: The expression of Nrf2 and HO-1 in cerebral cortex and hippocampus after cardiopulmonary resuscitation (CPR) was significantly increased and mild hypothermia up regulated this level. HE staining showed that mild hypothermia significantly improved neuronal injury.
Conclusion: Mild hypothermia has neuroprotective effects on cerebral ischemia/reperfusion injury after cardiac arrest. The possible mechanism is that Nrf2-ARE pathway in cerebral cortex and hippocampus after CPR is activated.

Keywords


1. Ali B, Zafari AM. Narrative review: cardiopulmonary resuscitation and emergency cardiovascular care: review of the current guidelines. Ann Intern Med 2007; 147:171–179.
2. Hua W, Zhang LF, Wu YF, Liu XQ, Guo DS, Zhou XL, et al. Incidence of sudden cardic death in China-analysis of 4 regional populations. JACC 2009; 54:1110-1118.
3. Robert WN, Jerry PN, Christophe A. Post–cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and Prognostication a consensus statement from the international liaison committee on resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation 2008; 118:2452-2483.
4. Laver S, Farrow C, Turner D, Nolan J. Mode of death after admission to an intensive care unit following cardiac arrest. Intensive Care Med 2004; 30:2126–2128.
5. Navaz K, Romergryko GG. Post-cardiac arrest syndrome update on brain injury management and prognostication. Curr Treat Options Neurol 2011; 13:191-203.
6. Kobayash M, Yamamoto M. Nrf2-keap1 regulation of cellular defense mechanisms against electrophiles and reactive oxygen species. Adv Enzyme Regul 2006; 46:113-140.
7. Chan KH, Ng MK, Stocker R. Haem oxygenase-1 and cardiovascular disease: mechanisms and therapeutic potential. Clin Sci 2011; 120:493-504.
8. Polderman KH. Mechanisms of action, physiological effects, and complications of hypothermia. Crit Care Med 2009; 37:S186–202.
9. Zhao H, Chen Y. Effects of mild hypothermia therapy on the levels of glutathione in rabbit blood and cerebrospinal fluid after cardiopulmonary resuscitation. Iran J Basic Med Sci 2015; 18:194-198.
10. Deniz T, Agalar C, Ozdogan M, Edremitlioglu M, Eryilmaz M, Devay SD, et al. Mild hypothermia improves survival during hemorrhagic shock without affecting bacterial translocation. J Invest Surg 2009; 22:22-28.
11. Takeuchi I, Takehana H, Satoh D, Fukaya H, Tamura Y, Nishi M, et al. Effect of hypothermia therapy after outpatient cardiac arrest due to ventricular fibrillation. Circ J 2009; 73:1877-1880.
12. Lu J, Shen Y, Qian H, Liu L, Zhou B, Xiao Y, et al. Effects of mild hypothermia on the ROS and expression of caspase-3 mRNA and LC3 of hippocampus nerve cells in rats after cardiopulmonary resuscitation. World J Emerg Med 2014; 4:298-304.
13. Idris AH, Becker LB, Ornato JP, Hedges JR, Bircher NG, Chandra NC, et al. Utstein-style guidelines for uniform reporting of laboratory CPR research. A statement for healthcare professionals from a task force of the American Heart Association, the American College of Emergency Physicians, the American College of Cardiology, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, the European Resuscitation Care Medicine, the Safar Center for Resuscitation Research, and the Society for Academic Emergency Medicine. Writing Group. Circulation 1996; 94:2324-2336.
14. Bano D, Nicotera P. Ca2+ signals and neuronal death in brain ischemia. Stroke 2007; 38:674-676.
15. Geocadin RG, Koenig MA, Stevens RD, Peberdy MA. Intensive care for brain injury after cardiac arrest: therapeutic hypothermia and related neuroprotective strategies. Crit Care Clin 2006; 22:619-636.
16. Lee JM, Shih AY, Murphy TH, Johnson JA. NF-E2-related factor-2 mediateds neuroproteciton against mitochondrial complex Ⅰ inhibitors and increased concentrations of intracellular calcium in primary cortical neurons. J Biol Chem 2003; 278:37948-37956.
17. Mizuno K, Kume T, Muto C, Takada-Takatori Y, Izumi Y, Sugimoto H, et al. Glutathione biosynthesis via activation of the nuclear factor E2-related factor 2 (Nrf2)--antioxidant-response element (ARE) pathway is essential for neuroprotective effects of sulforaphane and 6-(methylsulfinyl) hexyl isothiocyanate. J Pharmacol Sci 2011; 115:320-328.
18. Calkins MJ, Jakel RJ, Johnson DA, Chan K, Kan YW, Johnson JA. Protection from mitochondrial complex Ⅱ inhibition in vitro and in vivo by Nrf2-mediated transcription. Proc Natl Acad Sci USA 2005; 102:244-249.
19. Chen MJ, Wong CH, Peng ZF, Manikandan J, Melendez AJ, Tan TM, et al. A global transcriptomic view of the multifaceted role of glutathione peroxidase-1 in cerebral ischemic-reperfusion injury. Free Radic Biol Med 2011; 50:736-748.
20. Grigore AM, Murray CF, Ramakrishna H, Djaiani G. A Core Review of Temperature Regimens and Neuroprotection During Cardiopulmonary Bypass: Does Rewarming Rate Matter? Anesth. Analg 2009; 109:1741 – 1751.