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Wu D, Shi J, Elmadhoun O, Duan Y, An H, Zhang J, He X, Meng R, Liu X, Ji X, Ding Y. Dihydrocapsaicin (DHC) enhances the hypothermia-induced neuroprotection following ischemic stroke via PI3K/Akt regulation in rat. Brain Res 2017; 1671:18-25. [PMID: 28684048 DOI: 10.1016/j.brainres.2017.06.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Hypothermia has demonstrated neuroprotection following ischemia in preclinical studies while its clinical application is still very limited. The aim of this study was to explore whether combining local hypothermia in ischemic territory achieved by intra-arterial cold infusions (IACIs) with pharmacologically induced hypothermia enhances therapeutic outcomes, as well as the underlying mechanism. METHODS Sprague-Dawley rats were subjected to right middle cerebral artery occlusion (MCAO) for 2h using intraluminal hollow filament. The ischemic rats were randomized to receive: 1) pharmacological hypothermia by intraperitoneal (i.p.) injection of dihydrocapsaicin (DHC); 2) physical hypothermia by IACIs for 10min; or 3) the combined treatments. Extent of brain injury was determined by neurological deficit, infarct volume, and apoptotic cell death at 24h and/or 7d following reperfusion. ATP and ROS levels were measured. Expression of p-Akt, cleaved Caspase-3, pro-apoptotic (AIF, Bax) and anti-apoptotic proteins (Bcl-2, Bcl-xL) was evaluated at 24h. Finally, PI3K inhibitor was used to determine the effect of p-Akt. RESULTS DHC or IACIs each exhibited hypothermic effect and neuroprotection in rat MCAO models. The combination of pharmacological and physical approaches led to a faster and sustained reduction in brain temperatures and improved ischemia-induced injury than either alone (P<0.01). Furthermore, the combination treatment favorably increased the expression of anti-apoptotic proteins and decreased pro-apoptotic protein levels (P<0.01 or 0.05). This neuroprotective effect was largely blocked by p-Akt inhibition, indicating a potential role of Akt pathway in this mechanism (P<0.01 or 0.05). CONCLUSIONS The combination approach is able to enhance the efficiency of hypothermia and efficacy of hypothermia-induced neuroprotection following ischemic stroke. The findings here move us a step closer towards translating this long recognized TH from bench to bedside.
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Affiliation(s)
- Di Wu
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
| | - Jingfei Shi
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China
| | - Omar Elmadhoun
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Yunxia Duan
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hong An
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jun Zhang
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaoduo He
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ran Meng
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiangrong Liu
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xunming Ji
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China.
| | - Yuchuan Ding
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
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