Rgency brain resuscitation of patients with ischemic stroke, head trauma and

Rgency brain resuscitation of patients with ischemic stroke, head trauma and cardiac arrest [1,2,3,4,5]. The neuroprotective effects of mild hypothermia have been well documented in experimental models [6,7,8]. The precise mechanisms by which mild hypothermia protects the brain remain to be further elucidated. It is reported that hypothermia prevents cell death by multiple pathways. Among them, hypothermia attenuate cytochrome C (CytC) release and apoptosis [9] including the tumor necrotic factor (TNF) pathway or Fas-mediated extrinsic apoptosis pathway [10]. Earlier 94361-06-5 studies have found that hypothermia decreases P53 order TA-01 protein levels in the brain which activates genes of apoptosis and pro-apoptotic proteins including Bak,Bax, and PUMA. The Bcl-2 family is much influenced in the way that the pro-apoptotic proteins are inhibited which should have lead to the formation of pores in the mitochondria’s membrane, allowing the release of the cytochrome C to the cytosol, activating caspases, culminating in neuronal death [11,12,13]. Zhao [14] reported that biphasic CytC release occurred after transient global ischemia and mild hypothermia protects against ischemic damage by blocking the second phase (12 h, 24 h) of CytC release, possibly by blocking caspases activity. From the above studies, hypothermia can reduce the mitochondria pathway of apoptosis which also known as intrinsic apoptosispathway. Both the extrinsic and intrinsic apoptosis pathways ultimately activate caspases and then culminate in neuronal death. However, whether hypothermia can block endoplasmic reticulum mediated apoptosis is never known. Recent studies have illustrated the relationship between theendoplasmic reticulum stress(ER) stress and the mitochondria -mediated apoptosis pathway, especially the relationship between bcl-2 family and ER stress [15]. One of the upstream signals that activate these pathways is referred to ER stress. ER is the site for protein synthesis and folding, and also involved in calcium homeostasis and lipid biosynthesis. Many stimuli such as ischemia and hypoxia might perturb ER function resulting in accumulation of unfolded proteins in the ER lumen. This was also known as unfolded proteins response (UPR). Three ER transmembrane receptors named doublestranded RNA-dependent protein kinase-like ER kinase (PERK); inositol requiring enzyme-1 (IRE1) and activating transcription factor (ATF6) are activated to restore ER functions [16]. Firstly, ER chaperones [78-kDa glucose regulated protein (GRP78)] and ER-associated degradation of unfolded proteins as the initially a protective response of UPR. If the stress is prolonged UPR might activate enhancer binding protein homologous protein (chop), caspase-12 and c-Jun N-terminal kinase protein (JNK) [17]. Studies have showed chop is the downstream of all three ER stress pathways and plays an important role in endoplasmic reticulum stress [18]. Prolonged ER stress is implicated in the pathogenesis of ischemia and CHOP plays an important role in the cerebral ischemic damage induced by neuronal death. Up to now, there areHypothermia Attenuating Apoptosis through CHOPno prior studies examining the effects of hypothermia on the ER stress induced apoptotic pathway after transient global ischemia, so we explored these apoptotic events after transient global ischemia, and investigated the effects of hypothermia hypothermia against transient global ischemia through ER stress pathway in the transient global cerebral ische.Rgency brain resuscitation of patients with ischemic stroke, head trauma and cardiac arrest [1,2,3,4,5]. The neuroprotective effects of mild hypothermia have been well documented in experimental models [6,7,8]. The precise mechanisms by which mild hypothermia protects the brain remain to be further elucidated. It is reported that hypothermia prevents cell death by multiple pathways. Among them, hypothermia attenuate cytochrome C (CytC) release and apoptosis [9] including the tumor necrotic factor (TNF) pathway or Fas-mediated extrinsic apoptosis pathway [10]. Earlier studies have found that hypothermia decreases P53 protein levels in the brain which activates genes of apoptosis and pro-apoptotic proteins including Bak,Bax, and PUMA. The Bcl-2 family is much influenced in the way that the pro-apoptotic proteins are inhibited which should have lead to the formation of pores in the mitochondria’s membrane, allowing the release of the cytochrome C to the cytosol, activating caspases, culminating in neuronal death [11,12,13]. Zhao [14] reported that biphasic CytC release occurred after transient global ischemia and mild hypothermia protects against ischemic damage by blocking the second phase (12 h, 24 h) of CytC release, possibly by blocking caspases activity. From the above studies, hypothermia can reduce the mitochondria pathway of apoptosis which also known as intrinsic apoptosispathway. Both the extrinsic and intrinsic apoptosis pathways ultimately activate caspases and then culminate in neuronal death. However, whether hypothermia can block endoplasmic reticulum mediated apoptosis is never known. Recent studies have illustrated the relationship between theendoplasmic reticulum stress(ER) stress and the mitochondria -mediated apoptosis pathway, especially the relationship between bcl-2 family and ER stress [15]. One of the upstream signals that activate these pathways is referred to ER stress. ER is the site for protein synthesis and folding, and also involved in calcium homeostasis and lipid biosynthesis. Many stimuli such as ischemia and hypoxia might perturb ER function resulting in accumulation of unfolded proteins in the ER lumen. This was also known as unfolded proteins response (UPR). Three ER transmembrane receptors named doublestranded RNA-dependent protein kinase-like ER kinase (PERK); inositol requiring enzyme-1 (IRE1) and activating transcription factor (ATF6) are activated to restore ER functions [16]. Firstly, ER chaperones [78-kDa glucose regulated protein (GRP78)] and ER-associated degradation of unfolded proteins as the initially a protective response of UPR. If the stress is prolonged UPR might activate enhancer binding protein homologous protein (chop), caspase-12 and c-Jun N-terminal kinase protein (JNK) [17]. Studies have showed chop is the downstream of all three ER stress pathways and plays an important role in endoplasmic reticulum stress [18]. Prolonged ER stress is implicated in the pathogenesis of ischemia and CHOP plays an important role in the cerebral ischemic damage induced by neuronal death. Up to now, there areHypothermia Attenuating Apoptosis through CHOPno prior studies examining the effects of hypothermia on the ER stress induced apoptotic pathway after transient global ischemia, so we explored these apoptotic events after transient global ischemia, and investigated the effects of hypothermia hypothermia against transient global ischemia through ER stress pathway in the transient global cerebral ische.