2. Academic Validation
  3. Dihydrocapsaicin (DHC) enhances the hypothermia-induced neuroprotection following ischemic stroke via PI3K/Akt regulation in rat

Dihydrocapsaicin (DHC) enhances the hypothermia-induced neuroprotection following ischemic stroke via PI3K/Akt regulation in rat

  • Brain Res. 2017 Sep 15;1671:18-25. doi: 10.1016/j.brainres.2017.06.029.
Di Wu 1,  Jingfei Shi 2,  Omar Elmadhoun 3,  Yunxia Duan 4,  Hong An 4,  Jun Zhang 4,  Xiaoduo He 4,  Ran Meng 4,  Xiangrong Liu 4,  Xunming Ji 5,  Yuchuan Ding 6
Affiliations

Affiliations

  • 1 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.
  • 2 China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.
  • 3 Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA.
  • 4 China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China.
  • 5 China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China. Electronic address: [email protected].
  • 6 China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA.
PMID: 28684048 DOI: 10.1016/j.brainres.2017.06.029
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.

Keywords

Apoptotic cell death; Intra-arterial cold infusions (IACIs); Ischemia/reperfusion injury; Middle cerebral artery; Pharmacological hypothermia.

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