• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.3
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• pp.581-589
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• 2009

The water extract of Dohongsamul-tang(DHSMT) has been traditionally used in treatment of ischemic heart and brain diseases in Oriental Medicine. However, little is known about the mechanism by which DHSMT protects C6 glial cells from glucose deprevation induced damages. Therefore, this study was designed to evaluate the protective effects of DHSMT on 2-deoxy-D-glucose induced autophagy of C6 glial cells. Autophagic phenotype is evaluated by fluorescence microscopy and flow cytometry with specific biological staining dyes, including monodansylcadaverine and acridine orange, as well as Western blot analysis with microtubule-associated protein 1 light chain 3(LC3) and Beclin-1. Treatment with 2-deoxy-D-glucose significantly resulted in a decrease of the viability of C6 glial cells and increase of the extracellular LDH release in a dose and time-dependent manner. However, pretreatment with DHSMT protected C6 glial cells from glucose deprivation with 2-deoxy-D-glucose. The author also observed the fact that autophagy phenotype occurred by 2-deoxy-D-glucose in C6 glial cells. Pretreatment with 3-MA, a pharmacological inhibitior of autophagy, abolished the formation of acidic vesicle organelle in C6 glial cells treated with 2-deoxy-D-glucose. However, pretreatment with DHSMT inhibited the formation of autophagic phenotypes, including formation of acidic vesicle organelle, and increase of the expression of LC-3 II Beclin-1 proteins in C6 glial cells treated with 2-deoxy-D-glucose. Taken together, these data suggest that DHSMT is able to protect C6 glial cells from glucose deprivation with marked inhibition of autophagy formation.

• Toxicological Research
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• v.13 no.4
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• pp.359-365
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• 1997

Many factors are known to be responsible for cerebral ischemic injury, such as excitatory neurotransmitters, increased intraneuronal calcium, or disturbance of cellular energy metabolism. Recently, oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of ischemia/reperfusion injury. Therefore, to investigate the role of oxygen free radical during ischemia/reperfusion, in the present study the effect of endogenous oxygen free radical scavenger, superoxide dismutase / catalase(SOD / catalase) on the release of [$^3$H]-5-hydroxytryptamine([$^3$H]-5-HT) during hypoxia/reoxygenation in rat hippocampal slices was measured. The hippocampus was obtained from the rat brain and sliced 400 gm thickness with manual chopper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing [$^3$H]-5-HT(0.1 $\mu$M, 74 $\mu$Ci) for uptake, and washed. To measure the release of [$^3$H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Induction of hypoxia for 20 min (gassing it with 95% N$_2$/5% CO$_2$) was done in the 6th and 7th tube, and oxygen free radical scavenger, SOD / catalase was added 10 minutes prior to induction of hypoxia. The radioactivity in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. When slices were exposed to hypoxia for 20 min, [$^3$H]-5-HT release was markedly decreased and a rebound release of [$^3$H]-5-HT was observed on the post-hypoxic reoxygenation period. SOD / catalase did not changed the release of [$^3$H]-5-HT in control group, but inhibited the decrease of [$^3$H]-5-HT release in hypoxic period and rebound increase of [$^3$H]-5-HT in reoxygenation period. This result suggest that superoxide anion may play a role in the hypoxic-, and reoxygenation-induced change of [$^3$H]-5-HT release in rat hippocampal slices.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.236-242
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• 2004

Cerebral ischemia resulting from transient or permanent occlusion of cerebral arteries leads to neuronal cell death and eventually causes neurological impairments. Bee venom has been used for the treatment inflammatory disease. In the present study, the effects of bee venom on apoptosis and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils were investigated using immunohistochemistry for cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), caspase-3, and 5-bromo-2'-deoxyuridine (BrdU). It was shown that apoptotic cell death and cell proliferation in the hippocampal dentate gyrus were significantly increased following transient global ischemia in gerbils and that treatment of bee venom suppressed the ischemia-induced increase in apoptosis and cell proliferation in the dentate gyrus. The present results also showed that 1 mg/kg bee-venom treatment suppressed the ischemia-induced increasing apoptosis, cell proliferation, and COX-2 expression in the dentate gyrus. It is possible that the suppression of cell proliferation is due to the reduction of apoptotic cell death by treatment of bee venom. In the present study, bee venom was shown to prosses anti-apoptotic effect in ischemic brain disease, and this protective effect of bee venom against ischemia-induced neuronal cell death is closely associated with suppression on caspase-3 expression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1666-1672
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• 2005

Oriental medicinal drugs have a broad spectrum of clinical use for the cure of nervous system diseases including brain ischemic damages or neuropathies. Yet, specific drugs or drug components used in the oriental medicine in relation to none fiber regeneration are not known. In the present study, possible growth promoting effects of oriental medicinal drugs were investigated in the injured sciatic nerve system in the rat. By immunofluorescence staining, we found that Jahageo (JHG, Hominis placenta) increased Induction levels of axonal growth associated protein GAP-43 in the rat sciatic none. Small growth promoting activity was found in Golsebo (GSB, Drynariae rhizoma) and Baikhasuo (BHSO, Polygoni multiflori radix) drugs. JHG also increased cell cycle protein Cdc2 levels in the injured area of the sciatic nerves. Immunofluorescence staining indicated that induced Cdc2 protein was mostly localized in the Schwann cells in the injury area, implying that JHG activity might be related to increased Schwann cell proliferation during axonal regeneration. Moreover, levels of phospho-extracellular signal-regulated (ERK) pathway in the injured neNes were elevated by JHG treatment while levels of total ERK were unaltered. In vivo measurement of axonal regeneration using retrograde tracer showed that JHG, GSB and BHSO significantly enhanced Dil-labeled regenerating motor neurons compared with saline control. The present data suggest that oriental medicinal drugs such as JHG, GSB, and BHSO may be a useful target for developing specific drugs of axonal regeneration.

• The Journal of Korean Medicine
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• v.19 no.2
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• pp.59-74
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• 1998

Clinical observation was done on 272 cases of patients who were diagnosed as CVA with brain CT, TCD, MRI scan and clinical observation. They were hospitalized in the oriental medical hospital of Kyung-Won University from 1st January to 31st December in 1997. 1. The cases were classified into the following kinds: cerebral infarction, cerebral hemorrhage. and transient ischemic attack. The most case of them was the cerebral infarction. 2. There is no significant difference in the frequency of strokes in male and female. And the frequency of strokes was highest in the aged over 50. 3. In cerebral infarction the most frequent lesion was the territory of middle cerebral artery, and in cerebral hemorrhage the most frequent lesion was the basal ganglia. 4. The most ordinary preceding disease was hypertension. and the next was diabetes. 5. The rate of recurrence was high in cerebral infarction. 6. The cerebral infarction occurred usually in resting and sleeping, and the cerebral hemorrhage in acting. 7. The common symptoms were motor disability and verbal disturbance. 8 The average time to start physical therapy was 1l.3rd day after stroke in cerebral infarction and it was 15.2th day after stroke in cerebral hemorrhage. 9. The common complications were urinary tract infection, pneumonia, myocardial infarction. 10. Hypercholesterolemia and hypertriglyceridemia are usually found more frequently in cerebral infarction than in hemorrhage. 11. In acute or subacute stage, the methods of smoothening the flow of ki(順氣), dispelling phlegm(祛痰), clearing away heat(淸熱) or purgation(瀉下) were frequently used. and in recovering stage, the methods of replenishing ki(補氣), tonifying the blood(補血) or tranquilization(安神) were frequently used.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1752-1760
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• 2017

One of the treatments and preventions of strokes such as ischemic stroke is to increase cerebral blood flow. This aims to minimize the size of the stroke by increasing the quantity of blood to the cerebral region circuitously. Several ways to increase cerebral blood flow are a therapy though drugs and through surgery. However these invasive method giving a burden to the patient, the problem of inducing a number of complications were noted. In this thesis, we propose a non-invasive brain flow enhancer to complement the disadvantages of such invasive treatment methods. To compensate for the shortcomings of the existing devices, the patient's blood pressure is accurately measured and the blood pressure is applied to the extremities, thereby increasing blood flow to the femoral region to produce blood clotting treatments. Although somewhat inadequate blood flow increases compared to conventional devices, blood flow can be significantly increased, which can be selectively.

• BMB Reports
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• v.46 no.7
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• pp.370-375
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• 2013

Ischemia is characterized by oxidative stress and changes in the antioxidant defense system. Our recent in vitro study showed that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects cortical astrocytes against oxidative stress. In the current study, we examined the effects of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride on ischemia-induced neuronal damage in a gerbil ischemia/reperfusion models. Extensive neuronal death in the hippocampal CA1 area was observed 4 days after ischemia/reperfusion. Intraperitoneal injection of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride (0.3 mg/kg body weight) significantly prevented neuronal death in the CA1 region of the hippocampus in response to transient forebrain ischemia. 2-Cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride administration reduced ischemia-induced increases in reactive oxygen species levels and malondialdehyde content. It also attenuated the associated reductions in glutathione level and superoxide dismutase, catalase, and glutathione peroxidase activities. Taken together, our results suggest that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects against ischemia-induced neuronal damage by reducing oxidative stress through its antioxidant actions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.1010-1016
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• 2007

Sagunjatang (Sagunja), containing Radix Astragali, Radix Ginseng, Fructus Schizandrae, Radix Ophiopogonis and Radix Glycyrrhizae, has been used as a prescription for ischemic heart and brain diseases in Korean traditional medicine. This study was designed to investigate the protective mechanisms of Sagunja on $H_2O_2$-induced cytotoxicity of H9c2 cardiomyocytes. Treatment with $H_2O_2$ resulted in death of H9c2 cells, characterized by apparent apoptotic features, including the fragmentation of nucleus and increase in sub-GO/G1fraction of cell cycle. However, Sagunja markedly suppressed the apoptotic characteristics of H9c2 cells induced by $H_2O_2$ with decrease of intracellular peroxide level. In addition, Sagunja suppressed the features of mitochondrial dysfunction, including change of mitochondrial membrane potential, in $H_2O_2$- treated cells. Additionally, Sagunja induced the expression of HO-1 protein in both time-and dose-dependent manner. The role of HO-1 in ROS-scavenging activity of Sagunja is proposed.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.423-429
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• 2012

Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.