• The Korean Journal of Physiology and Pharmacology
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• v.25 no.6
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• pp.565-574
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• 2021

Astrocytes are activated in response to brain damage. Here, we found that expression of Kir4.1, a major potassium channel in astrocytes, is increased in activated astrocytes in the injured brain together with upregulation of the neural stem cell markers, Sox2 and Nestin. Expression of Kir4.1 was also increased together with that of Nestin and Sox2 in neurospheres formed from dissociated P7 mouse brains. Using the Kir4.1 blocker BaCl₂ to determine whether Kir4.1 is involved in acquisition of stemness, we found that inhibition of Kir4.1 activity caused a concentration-dependent increase in sphere size and Sox2 levels, but had little effect on Nestin levels. Moreover, induction of differentiation of cultured neural stem cells by withdrawing epidermal growth factor and fibroblast growth factor from the culture medium caused a sharp initial increase in Kir4.1 expression followed by a decrease, whereas Sox2 and Nestin levels continuously decreased. Inhibition of Kir4.1 had no effect on expression levels of Sox2 or Nestin, or the astrocyte and neuron markers glial fibrillary acidic protein and β-tubulin III, respectively. Taken together, these results indicate that Kir4.1 may control gain of stemness but not differentiation of stem cells.

• Journal of Acupuncture Research
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• v.32 no.1
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• pp.23-36
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• 2015

Objectives : This study was designed to investigate the neuroprotective effects of Hominis-Placenta (HP)on dopaminergic neurons. Methods : We examined the effect of invitro administration of HP against 1-methyl-4-phenylpyridinium( MPP+)-induced dopaminergic cell loss in primary mesencephalic culture and also used behavioral tests and performed analysis in the striatum and the substantia nigra of mouse brain, to confirm the effect of HP on dopaminergic neurons in an invivo 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mouse model. Animals were assigned to four groups: (1) Group 1(vehicle-treatedgroup), (2) Group 2(MPTPonlytreated group), (3) Group 3(MPTP+ saline-treated/$ST_{36}$ group), and (4) Group 4(MPTP+HP-treated/$ST_{36}$ group). HP at $20{\mu}L$ of 48 mg/kg dose was injected at $ST_{36}$ for 4 weeks at 2-day intervals. MPTP in saline was injected intraperitoneally each day for 5 days from the $8_{th}$ treatment of HP. We performed the pole test and rota-rod test on the first and seventh day after the last MPTP injection. To investigate the effect of HP on dopaminergic neurons, we performed analysis in the striatum and the substantia nigra of mouse brain after treatment with HP and/or MPTP. Results : Treatment with HP had no influence on cell proliferation and caused no cell toxicity in $PC_{12}$ and $HT_{22}$ cells. Our study showed that HP significantly prevented cell loss and protected neurites against MPP+ toxicity. Although the invivo treatment of HP herbal acupuncture at $ST_{36}$ showed a tendency to improve movement ability and protected dopaminergic cells and fibers in the substantia nigra and the striatum, it did not show significant changes compared with the MPTP treated group. Conclusions : These data suggest that HP could be a potential treatment strategy in neurodegenerative diseases such as Parkinson's disease.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.743-746
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• 2003

The major pathological lesion in Parkinson's disease(PD) is selective degeneration and loss of pigmented dopaminergic neurons in substantia nigra (SN). Although the initial cause and subsequent molecular signaling mechanisms leading to the dopaminergic cell death underlying the PD process is elusive, the potent neurotrophic factors (NTFs), brain derived neurotrophic factor (BDNF) and glial cell line derived neurotrophic factor (GDNF), are known to exert dopaminergic neuroprotection both in vivo and in vitro models of PD employing the neurotoxin, MPTP. BDNF and its receptor, trkB are expressed in SN dopaminergic neurons and their innervation target. Thus, neurotrophins may have autocrine, paracrine and retrograde transport effects on the SN dopaminergic neurons. This study determined the BDNF secretion from SN dopaminergic neurons by ELISA. Regulation of BDNF synthesis/release and changes in signaling pathways are monitored in the presence of free radical donor, NO donor and mitochondrial inhibitors. Also, this study shows that BDNF is able to promote survival and phenotypic differentiation of SN dopaminergic neurons in culture and protect them against MPTP-induced neurotoxicity via MAP kinase pathway.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1573-1578
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• 2007

An increasing number of applications is being developed for the use of nanoparticles in various fields. We investigated possible toxicities of nanoparticles in cell culture and in mice. Nanoparticles tested were Zn (300 nm), Fe (100 nm), and Si (10-20, 40-50, and 90-110 nm). The cell lines used were brain, liver, stomach, and lung from humans. In the presence of nanopaticles, mitochodrial activity decreased zero to 15%. DNA contents decreased zero to 20%, and glutathione production increased zero to 15%. None of them showed a dose dependency. Plasma membrane permeability was not altered by nanoparticles. In the case of Si, different sizes of the nanoparticles did not affect cytotoxicity. The cytotoxicity was also shown to be similar in the presence of micro-sized ($45\;{\mu}m$) Si particles. Organs from mice fed with nanoparticles showed nonspecific hemorrhage, lymphocytic infiltration, and medullary congestion. A treatment with the micro-sized particle showed similar results, suggesting that the acute in vivo toxicity was not altered by nano-sized particles.

• The Journal of Internal Korean Medicine
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• v.25 no.3
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• pp.461-472
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• 2004

Objectives : For the screening of neuroprotective effects of medicinal herbs, the complex system of animal models suffer some disadvantages in controlling critical parameters such as blood pressure and body temperature. Additionally, application of drugs to the appropriate brain area sometimes is difficult, due to poor permeability though the blood brain barrier, and so potential protective effects might be masked. Methods : Organotypic hippocampal slice culture (OHSC) method has the advantages of being relatively easy to prepare and of maintaining the general structure, including tissue integrity and the connections between cells. Drugs can easily be applied and neuronal damage can easily be quantified by using tissues and culture media. This study demonstrates neuroprotective effects of Puerariae radix (葛根, PR), Salviae miltiorrhizae radix (丹蔘, SR), Rhei rhizoma (大黃, RR), and Bupleuri radix (柴胡, BR). These were screenedand compared to MK-801, antagonist of NMDA receptors, by using OHSC of 1 week-old Sprague-Dawley rats. Oxygen/glucose deprivation (OGD) were conducted in an anaerobic chamber $(85%\;N_2,\;10%\;CO_2\;and\;5%\;H_2)$ in a deoxygenated glucose-free medium for 60 minutes. Water extracts of each herbs were treated to culture media with $5\;{\mu}g/ml$ for 48 hours. Results : Neuronal cell death in the cultures was monitored by densitometric measurements of the cellular uptake of propidium iodide (PI). PI fluorescence images were obtained at 48 hours after the OGD and medicinal herb treatment. Also TUNEL-positive cells in the CAI and DG regions and LDH concentrations in culture media were measured at 48 hours after the OGD. According to measured data, MK-801, PR, SR and BR demonstrated significant neuroprotective effect against excessive neuronal cell death and apoptosis induced by the OGD insult. Especially, PR revealed similar neuroprotective effect to MK-801 and RR demonstrated weak neuroprotective effect. Conclusions : These results suggest that OHSC can be a suitable method for screening of neuroprotective effects of medicinal herbs. (This work was supported by the research program of Dongguk University and Grant 01-PJ9-PG1-01CO03-0003 from Ministry of Health & Welfare.)

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.29-40
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• 2003

Object : This research was performed to investigate the protective effect of Aurantii Immaturus Fructus against ischemic damage using PC12 cells and global ischemia in gerbils. Methods : To observe the protective effect of Aurantii Immaturus Fructus on ischemia damage, viability and changes in activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and production of malondialdehyde (MDA) were observed after treating PC12 cells with Aurantii Immaturus Fructus during ischemic insult. Gerbils were divided into three groups : a normal group, a 5-min two-vessel occlusion (2VO) group, and an Aurantii Immaturus Fructus administered after 2VO group. The CCAs were occluded by microclip for 5 minutes. Aurantii Immaturus Fructus was administered orally for 7 days after 2VO. The histological analysis was performed at 7 days after the surgery. For histological analysis, the brain tissue was stained with 1% cresyl violet solution. Results : The results showed that 1. Aurantii Immaturus Fructus had a protective effect against ischemia in the CAI area of the gerbil hippocampus 7 days after 5-minute occlusion, 2. In the hypoxia/reperfusion model using PC12 cells, the Aurantii Immaturus Fructus had a protective effect against ischemia in the dose of $0.2{\;}\mu\textrm{g}/ml,{\;}2{\;}\mu\textrm{g}/ml{\;}and{\;}20{\;}\mu\textrm{g}/ml$ 3. Aurantii Immaturus Fructus increased the activities of glutathione peroxidase and catalase, 4. The activity of superoxide dismutase (SOD) was increased by ischemic damage, which might represent self protection. This study suggests that Aurantii Immaturus Fructus has some neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils, and it also has protective effects on a hypoxia/reperfusion cell culture model using PCq2 cells. Conclusions : Aurantii Immaturus Fructus has protective effects against ischemic brain damage at the early stage of ischemia.

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.110-121
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• 2003

Objective : This research was performed to investigate the protective effect of Angelicae Dahuri Radix against ischemic damage using PC12 cells and global ischemia in gerbils. Methods : To observe the protective effect of Angelicae Dahuri Radix on ischemia damage, viability and changes in activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and production of malondialdehyde (MDA) were observed after treating PC12 cells with Angelicae Dahuri Radix during ischemic insult. Gerbils were divided into three groups : a normal group, a 5-min two-vessel occlusion (2VO) group, and an Angelicae Dahuri Radix administered after 2VO group. The CCAs were occluded by microclip for 5 minutes. Angelicae Dahuri Radix was administered orally for 7 days after 2VO. The histological analysis was performed at 7 days after surgery. For histological analysis, the brain tissue was stained with 1% cresyl violet solution. Results : 1. Angelicae Dahuri Radix has a protective effect against ischemia in the CA1 area of the gerbil hippocampus 7 days after 5-minute occlusion, 2. In the hypoxia/reperfusion model using PC12 cells, Angelicae Dahuri Radix has a protective effect against ischemia in the dose of $0.2\mu\textrm{g}/ml$, $2\mu\textrm{g}/ml$ and $20\mu\textrm{g}/ml$, 3. Angelicae Dahuri Radix increased the activities of glutathione peroxidase and catalase. 4. The activity of superoxide dismutase (SOD) was increased by ischemic damage, which might represent self protection. This study suggests that Angelicae Dahuri Radix has some neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils, and it also has protective effects on a hypoxia/reperfusion cell culture model using PC12 cells. Conclusions : Angelicae Dahuri Radix has protective effects against ischemic brain damage at the early stage of ischemia.

• The Journal of Korean Medicine
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• v.23 no.4
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• pp.113-124
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• 2002

Objects: This research was conducted to investigate the protective effect of Bupleuri Radix against ischemic damage using PC12 cells and global ischemia in gerbils, Methods: To observe the protective effect of Bupleuri Radixon ischemic damage, viability and changes in activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and production of malondialdehyde (MDA) were observed after treating PC12 cells with Bupleuri Radix during ischemic damage. Gerbils were divided into three groups: a normal group, a 5-minute two-vessel occlusion (2VO) group and a Bupleun Radix administered group after 2VO. The CCAs were occluded by microclip for 5 minutes, Bupleuri Radix was administered orally for 7 days after 2VO. Histological analysis was performed on the 7th day. For histological analysis, the brain tissue was stained with 1 % of cresyl violet solution. Results: 1. Bupleuri Radix has a protective effect against ischemia in the CA1 area of the gerbil's hippocampus 7 days after 5-minute occlusion. 2. In the hypoxia/reperfusion model using PC12 cells, the Bupleuri Radix has a protective effect against ischemia in the dose of 0.2{\;}\mu\textrm{g}/ml,2{\;}\mu\textrm{g}/ml{\;}and{\;} 20{\;}\mu\textrm{g}/ml$. 3. Bupleuri Radix increased the activities of glutathione peroxidase and catalase. 4. The increased activity of superoxidedismutase (SOD) by ischemic damage might have been induced as an act of self-protection. This study suggests that Bupleuri Radix has some neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils. Bupleuri Radix also has protective effect on a hypoxia/reperfusion cell culture model using PC12 cells. Conclusions: Bupleuri Radix has protective effect against ischemic brain damage during the early stages of ischemia.

• Journal of Acupuncture Research
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• v.36 no.3
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• pp.140-146
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• 2019

Background: This study investigated the effects of Vipera lebetina turanica snake venom (SV) on cerebral infarction induced by middle cerebral artery occlusion in mice. Methods: Following cerebral infarction, SV was injected intravenously or added to BV2 cell culture. Tissue injury was detected using triphenyltetrazolium chloride (TTC) staining, neurological deficit score, NO, ROS, and GSH/GSSG assays, qPCR, Western blot, and cell viability. Results: Cerebral infarction caused by middle cerebral artery occlusion as observed by TTC staining, showed SV inhibited cell death, reducing the number of brain cells injured due to infarction. SV treatment for cerebral infarction showed a significant decrease in abnormal behavior, as determined by the neurological deficit score. The oxidation and inflammation of the cells that had cerebral infarction caused by middle cerebral artery occlusion (NO assay, ROS, GSH/GSSG assay, and qPCR), showed significant protection by SV. Western blot of brain infarction cells showed the expression of iNOS, COX-2, p-IkB-${\alpha}$, P38, p-JNK, p-ERK to be lower in the SV group. In addition, the expression of IkB increased. BV2 cells were viable when treated with SV at $20{\mu}g/mL$ or less. Western blot of BV2 cells, treated with 0.625, 1.5, $2.5{\mu}g/mL$ of SV, showed a significant decrease in the expression of p-IkB-${\alpha}$, p-JNK, iNOS, and COX-2 on BV2 cells induced by LPS. Conclusion: SV showed anti-inflammatory and anti-oxidant effects against cerebral infarction and inflammation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1401-1406
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• 2007

The present study investigated neuroprotective effects Rehmanniae Radix on PC12 cells and hippocampal neural cells. PC12 cells were damage by $H_2O_2$ and nitric oxide and organotypic hippocampal slice cultures were damaged by oxygen-glucose deprivation. Then methanol extract of Rehmanniae Radix was treated with 0.5, 5, and $50\;{\mu}g/ml$ in culture media. Effects of Rehmanniae Radix were evaluated with cell viability assay, PI-staining, and TUNEL-labeling. Treatment of Rehmanniae Radix ($with\;5\;and\;50\;{\mu}g/ml$) produced significant increase of cell viability of PC12 cells damaged by $H_2O_2$ and by SNP-induced nitric oxide. Treatment of Rehmanniae Radix produced significant decrease of PI-uptake % in CA1 ($with\;5\;and\;50\;{\mu}g/ml$) and DG ($with\;50\;{\mu}g/ml$) regions of organotypic hippocampal slice cultures damaged by oxygen-glucose deprivation. Moreover, treatment of Rehmanniae Radix produced significant decrease of TUNEL- positive cells in CA1 ($with\;5\;and\;50\;{\mu}g/ml$) and DG ($with\;50\;{\mu}g/ml$) regions of organotypic hippocampal slice cultures damaged by oxygen-glucose deprivation. These results suggest that methanol extract of Rehmanniae Radix has neuroprotective effects on PC12 cells damaged by oxidative stress and on organotypic hippocampal slice cultures damaged by oxygen-glucose deprivation.