• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.181-188
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• 2017

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.272-278
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• 2017

Fucoidan has been reported to exhibit various beneficial activities ranging from to antivirus and anticancer properties. However, little information is available about the effects of fucoidan on cerebral ischemia-reperfusion injury (IRI). Our study aimed to explore the effects of fucoidan on cerebral IRI, as well as the underlying mechanisms. Sprague-Dawley (SD) rats were randomly subjected to four groups: Sham, IRI+saline (IRI+S), IRI+80 mg/kg fucoidan (IRI+F80), and IRI+160 mg/kg fucoidan (IRI+F160). Fucoidan (80 mg/kg or 160 mg/kg) was intraperitoneally injected from 7 days before the rats were induced to cerebral IRI model with middle cerebral artery occlusion (MCAO) method. At 24 h after reperfusion, neurological deficits and the total infarct volume were determined. The levels of inflammation-associated cytokines (interleukin (IL)-$1{\beta}$, IL-6, myeloperoxidase (MPO), and tumor necrosis factor (TNF)-${\alpha}$), oxidative stress-related proteins (malondialdehyde (MDA) and superoxide dismutase (SOD)) in the ischemic brain were measured by enzyme-linked immunosorbent assay (ELISA). Besides, the levels of apoptosis-related proteins (p-53, Bax, and B-cell lymphoma (Bcl)-2) and mitogen-activated protein kinase (MAPK) pathway (phosphorylation-extracellular signal-regulated kinase (p-ERK), p-c-Jun N-terminal kinase (JNK), and p-p38) were measured. Results showed that administration of fucoidan significantly reduced the neurological deficits and infarct volume compared to the IRI+S group in a dose-dependent manner. Also, fucoidan statistically decreased the levels of inflammation-associated cytokines, and oxidative stress-related proteins, inhibited apoptosis, and suppressed the MAPK pathway. So, Fucoidan plays a protective role in cerebral IRI might be by inhibition of MAPK pathway.

• Journal of Trauma and Injury
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• v.28 no.4
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• pp.232-240
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• 2015

Purpose: Thoracic aortic injury is a life-threatening injury that has been traditionally treated by using surgical management. Recently, thoracic endovascular aortic repair (TEVAR) has been conducted pervasively as a better alternative treatment method. Therefore, this study will focus on analyzing the outcome of TEVAR in patients suffering from a blunt thoracic aortic injury. Methods: Of the blunt thoracic aortic injury patients admitted to Eulji University Hospital, this research focused on the 11 patients who had received TEVAR during the period from January 2008 to April 2014. Results: Seven of the 11 patients were male. At the time of admission, the mean systolic pressure was $105.64{\pm}24.60mm\;Hg$, and the mean heart rate was $103.64{\pm}20.02per$ minute. The median interval from arrival to repair was 7 (4, 47) hours. The mean stay in the ICU was $21.82{\pm}16.37hours$. In three patients, a chimney graft technique was also performed to save the left subclavian artery. In one patient, a debranching of the aortic arch vessels was performed. In two patients, the left subclavian artery was totally covered. In one patient whose proximal aortic neck length was insufficient, the landing zone was extended by using a prophylactic left subclavian artery to left common carotid artery bypass before TEVAR. There were no operative mortalities, but a patient who was covered of left subclavian artery died from ischemic brain injury. Complications such as migration, endovascular leakage, collapse, infection and thrombus did not occur. Conclusion: Our short-term outcomes of TEVAR for blunt thoracic aorta injury was feasible. Left subclavian artery may be sacrificed if the proximal landing zone is short, but several methods to continue the perfusion should be considered.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.107-112
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• 2010

The majority of strokes are caused by ischemia and result in brain tissue damage, leading to problems of the central nervous system including hemiparesis, dysfunction of language and consciousness, and dysfunction of perception. The purpose of this study was to investigate the effects of Poly(ADP-ribose) polymerase(PARP) on necrosis in neuronal cells that have undergone needle electrode electrical stimulation(NEES) prior to induction of ischemia. Ischemia was induced in male SD rats(body weight 300g) by occlusion of the common carotid artery for 5 min, after which the blood was reperfused. After induction of brain ischemia, NEES was applied to Zusanli(ST 36), at 12, 24 and 48 hours. Protein expression was investigated using immuno-reactive cells, which react to PARP antibodies in cerebral nerve cells, and Western blotting. The results were as follows: In the cerebral cortex, the number of PARP reactive cells after 24 hours significantly decreased(p<.05) in the NEES group compared to the GI group. PARP expression after 24 hours significantly decreased(p<.05) in the NEES group compared to the GI group. As a result, NEES showed the greatest effect on necrosis-related PARP immuno-reactive cells 24 hours after ischemia, indicating necrosis inhibition, blocking of neural cell death, and protection of neural cells. Based on the results of this study, NEES can be an effective method of treating dysfunction and improving function of neuronal cells in brain damage caused by ischemia.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.129-139
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• 2016

Curcumin plays a protective role in brain injury through its anti-oxidant and anti-inflammatory activities. Moreover, peroxiredoxin-5 exerts a protective effect against oxidative stress. The aim of this study was to investigate whether curcumin modulated the peroxiredoxin-5 expression in focal cerebral ischemic animal model. Middle cerebral artery occlusion(MCAO) was performed to induce cerebral ischemic injury in rats. Adult male rats were injected intraperitoneally with vehicle or curcumin(50mg/kg B.W.) 1 h after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Photographs of hematoxylin and eosin staining showed that MCAO induced necrotic changes with scalloped shrunken form and apoptotic changes with nuclear chromatin condensations. However, curcumin treatment attenuated MCAO-induced histopathological changes. Moreover, this study clearly showed that peroxiredoxin-5 expression was decreased in MCAO operated animal with vehicle using a proteomics approach. However, this decrease in peroxiredoxin-5 expression was attenuated by curcumin treatment. Reverse-transcription PCR and Western blot analyses confirmed that curcumin treatment alleviated the MCAO injury-induced decrease in peroxiredoxin-5 expression(p<0.05). These results demonstrated that curcumin regulates peroxiredoxin-5 expression in MCAO animal model. In conclusion, our findings suggest that curcumin exerts a neuroprotective effect in cerebral ischemia by attenuating the MCAO-induced decrease in peroxiredoxin-5 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.681-690
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• 1997

Loss of synaptic transmission and accumulation of extracellular $K^+([K^+]_O)$ are the key features in ischemic brain damage. Here, we examined the effects of several $K^+$channel modulators on the early ischemic changes in population spike (PS) and $[K^+]_o$ in the CA1 pyramidal layer of the rat hippocampal slice using electrophysiological techniques. After onset of anoxic aglycemia (AA), orthodromic field potentials decreased and disappeared in $3.3{\pm}0.22\;min$ $(mean{\pm}SEM,\;n=40)$. The hypoxic injury potential (HIP), a transient recovery of PS appeared at $6.0{\pm}0.25\;min$ (n=40) in most slices during AA and lasted for $3.3{\pm}0.43\;min$. $[K^+]_o$ increased initially at a rate of 0.43 mM/min (Phase 1) and later at a much faster rate (12.45 mM/min, Phase 2). The beginning of Phase 2 was invariably coincided with the disappearance of HIP. Among $K^+$ channel modulators tested such as 4-aminopyridine (0.03, 0.3 mM), tetraethylammonium (0.1 mM), NS1619 $(0.3{\sim}10\;{\mu}M)$, niflumic acid (0.1 mM), glibenclamide $(40\;{\mu}M)$, tolbutamide $(300\;{\mu}M)$ and pinacidil $(100\;{\mu}M)$, only 4-aminopyridine (0.3 mM) induced slight increase of $[K^+]_o$ during Phase 1. However, none of the above agents modulated the pattern of Phase 2 in $[K^+]_o$ in response to AA. Taken together, the experimental data suggest that 4-aminopyridine-sensitive $K^+$channels, large conductance $Ca^{2+}-activated$ $K^+$ channels and ATP-sensitive $K^+$ channels may not be the major contributors to the sudden increase of $[K^+]_o$ during the early stage of brain ischemia, suggesting the presence of other routes of $K^+$ efflux during brain ischemia.

• Journal of Korean Neurosurgical Society
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• v.59 no.6
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• pp.544-550
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• 2016

Objective : Cerebral endothelial cells have unique biological features and are fascinating candidate cells for stroke therapy. Methods : In order to understand the molecular mechanisms of human cerebral endothelial cell (hCMEC/D3) transplantation in a rat stroke model, we performed proteomic analysis using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein expression was confirmed by quantitative real-time PCR and Western blot. Results : Several protein spots were identified by gel electrophoresis in the sham, cerebral ischemia (CI), and CI with hCMEC/D3 treatment cerebral ischemia with cell transplantation (CT) groups, and we identified 14 differentially expressed proteins in the CT group. Proteins involved in mitochondrial dysfunction (paraplegin matrix AAA peptidase subunit, SPG7), neuroinflammation (peroxiredoxin 6, PRDX6), and neuronal death (zinc finger protein 90, ZFP90) were markedly reduced in the CT group compared with the CI group. The expression of chloride intracellular channel 4 proteins involved in post-ischemic vasculogenesis was significantly decreased in the CI group but comparable to sham in the CT group. Conclusion : These results contribute to our understanding of the early phase processes that follow cerebral endothelial cell treatment in CI. Moreover, some of the identified proteins may present promising new targets for stroke therapy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1459-1466
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• 2006

The water extract of Hwansodan has been traditionally used for treatment of ischemic brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of Hwansodan rescues cells from neurodegenerative disease. PC12 pheochromocytoma cells have been used extensively as a model for studying the cellular and molecular mechanisms of neuronal cell damages. Under deprivation of growth factor and ischemic injury, PC12 cells spontaneously undergoes apoptotic cell death. Serum and glucose deprivation markedly decreased the viability of PC12 cells, which was characterized with apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the aqueous extract of Hwansodan significantly reduced serum and glucose deprivation-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Pretreatment of Hwansodan also ingibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 was completely abolished in serum and glucose deprivated cells. Furthermore, pretreatment of Hwansodan obviously increased heme oxygenase 1 (HO-1) expression in PC12 cells. Taken together, the data suggest that the protective effects of Hwansodan against serum and glucose deprivation induced oxidative injuries may be achieved through the scavenging of reactive oxygene species accompanying with HO-1 induction.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.273-289
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• 1994

Reversible brain ischemia was produced by occluding both common carotid arteries for 5 min, and the effects of aminoguanidine (AG), $DL-{\alpha}-difluoromethylornithine$ (DFMO), MK-801, and nimodipine (NM) on the ischemia induced changes of the polyamine, glutamate and acetylcholine levels in the hippocampus CA1 subfield and the specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membranes were studied with a histological reference of the cresyl violet stained hippocampus. The basal putrescine level $(PT:\;74.4{\pm}8.8\;nM)$ showed a rapid increase (up to 1.7 fold) for 5 min of ischemia, remained significantly increased for 6 h, and then resumed the further increase to amount gradually up to about 3 fold 96 h after recirculation. However, the level of spermidine was little changed, and the spermine level showed a transient increase during ischemia followed by a sustained decrease to about 40% of the preischemic level after recirculation. The increase of PT level induced by brain ischemia was enhanced with AG or MK-801, but it was reduced by DFMO or NM. The basal glutamate level $(GT:\;0.90{\pm}0.l4\;{\mu}M)$ rapidly increased to a peak level of $8.19{\pm}1.14\;{\mu}M$ within 5 min after onset of the ischemia and then decreased to the preischemic level in about 25 min after recirculation. And NM reduced the ischemia induced increase of GT level by about 25%, but AG, DFMO and MK-801 did not affect the GT increase. The basal acetylcholine level $(ACh:\;118.0{\pm}10.5\;{\mu}M)$ did little change during/after brain ischemia and was little affected by AG or NM. But DFMO and MK-801, respectively, produced the moderate decrease of ACh level. The specific $[^3H]\;MK-801$ binding to the hippocampus synaptosomal membrane was little affected by brain ischemia for 5 min. The control value (78.9 fmole/mg protein) was moderately decreased by AG and MK-801, respectively but was little changed by DFMO or NM. The microscopic findings of the brains extirpated on day 7 after ischemia showed severe neuronal damage of the hippocampus, particularly CA1 subfield. NM and AG moderately attenuated the delayed neuronal damage, and DFMO, on the contrary, aggravated the ischemia induced damage. However, MK-801 did not protect the hippocampus from ischemic damage. These results suggest that unlike to the mode of anti-ischemic action of NM, AG might protect the hippocampus from ischemic injury as being negatively regulatory on the N-methyl-D-aspartate (NMDA) receptor function in the hippocampus.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7069-7074
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• 2013

Programmed cell death is a basic cellular process that is critical to maintaining tissue homeostasis. In contrast to apoptosis, necrosis was previously regarded as an unregulated and uncontrollable process. However, as research has progressed, necrosis, also known as necroptosis or programmed necrosis, is drawing increasing attention, not least becasu of its possible impications for cancer research. Necroptosis exhibits a unique signaling pathway that requires the involvement of receptor interaction protein kinases 1 and 3 (RIP1 and RIP3), mixed lineage kinase domain-like (MLKL), and phosphoglycerate mutase 5 (PGAM5) and can be specifically inhibited by necrostatins. Not only does necroptosis serve as a backup cell death program when apoptosis is inhibited, but it is now recognized to play a pivotal role in regulating various physiological processes and the pathogenesis of a variety of human diseases such as ischemic brain injury, immune system disorders and cancer. The control of necroptosis by various defined trigger factors and signaling pathways now offers the opportunity to target this cellular process for therapeutic purposes. The purpose of this paper is to review current findings concerning the connections between various trigger factors and the RIP1/RIP3 signaling pathway as it relates to necroptosis.