• Molecules and Cells
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• v.40 no.7
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• pp.495-502
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• 2017

The $5-HT_6R$ has been considered as an attractive therapeutic target in the brain due to its exclusive expression in the brain. However, the mechanistic linkage between $5-HT_6Rs$ and brain functions remains poorly understood. Here, we examined the effects of $5-HT_6R$-mediated cell morphological changes using immunocytochemistry, Western blot, and live-cell imaging assays. Our results showed that the activation of $5-HT_6Rs$ caused morphological changes and increased cell surface area in HEK293 cells expressing $5-HT_6Rs$. Treatment with 5-HT specifically increased RhoA-GTP activity without affecting other Rho family proteins, such as Rac1 and Cdc42. Furthermore, live-cell imaging in hippocampal neurons revealed that activation of $5-HT_6Rs$ using a selective agonist, ST1936, increased the density and size of dendritic protrusions along with the activation of RhoA-GTP activity and that both effects were blocked by pretreatment with a selective $5-HT_6R$ antagonist, SB258585. Taken together, our results show that $5-HT_6R$ plays an important role in the regulation of cell morphology via a RhoA-dependent pathway in mammalian cell lines and primary neurons.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.41-46
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• 2005

Objective : A study of the histopathologic and neurobehavioral correlates of cortical impact injury produced by increasing impact velocity using the controlled cortical impact[CCI] injury model is studied. Methods : Twenty-four Sprague-Dawley rats [$200{\sim}250g$] were given CCI injury using a pneumatically driven piston. Effect of impact velocity on a 3mm deformation was assessed at 2.5m/sec [n=6], 3.0m/sec [n=6], 3.5m/sec [n=6], and no injury [n=6]. After postoperative 24hours the rats were evaluated using several neurobehavioral tests including the rotarod test, beam-balance performance, and postural reflex test. Contusion volume and histopathologic findings were evaluated for each of the impact velocities. Results : On the rota rod test, all the injured rats exhibited a significant difference compared to the sham-operated rats and increased velocity correlated with increased deficit [p<0.001]. Contusion volume increased with increasing impact velocity. For the 2.5, 3.0, and 3.5m/sec groups, injured volumes were $18.8{\pm}2.3mm^3$, $26.8{\pm}3.1mm^3$, and $32.5{\pm}3.5mm^3$, respectively. In addition, neuronal loss in the hippocampal sub-region increased with increasing impact velocity. In the TUNEL staining, all the injured groups exhibited definitely positive cells at pericontusional area. However, there were no significant differences in the number of positive cells among the injured groups. Conclusion : Cortical impact velocity is a critical parameter in producing cortical contusion. Severity of cortical injury is proportional to increasing impact velocity of cortical injury.

• Physical Therapy Korea
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• v.12 no.3
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• pp.11-21
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• 2005

The present study was aimed at investigating the effect of swimming training on brain function after focal cerebral ischemia in rats. Therefore, this study was examined on neurogenesis in dentate gyrus of hippocampus using 5-bromo-2'-deoxyuridine (BrdU) to label proliferating cells and assessed the neurological response following focal cerebral ischemia in rats using neurological motor behavioral test. In an observer-blinded fashion, twenty male Sprague-Dawley (280~310 g, 7 weeks old) rats were divided into four groups: MCAO plus swimming group (ME, $n_1$=5), MCAO plus control group (MC, $n_2$=5), SHAM plus swimming group (SE, $n_3$=5), SHAM plus control group (SC, $n_4$=5). The results of this study were as follows: 1) The limb placing time before and after swimming in the ME group were significantly longer than the MC group (p<.05), the SE group were significantly longer than the SC group (p<.01). 2) The balance beam scores before and after swimming in the ME group was higher than the SE group, the MC group was higher than the SC group but was not significantly different (p>.001). 3) The foot fault index before and after swimming training in ME group was significantly lower (i.e., improved) than the MC group (p<.001) and the SE group (p<.001), the SE group was significantly lower (i.e., improved) than the SC group (p<.001). 4) The mean number of BrdU-positive cells in the dentate gyrus in the ME group was significantly higher than the MC group (p<.001) and the SE group (p<.01). The MC group and the SE group was significantly higher than the SC group (p<.001). 5) There was significantly correlation between limb placing time and number of BrdU-positive cells on swimming training, there was positive correlation (r=.807, p<.0001) and between foot fault index and BrdU-positive cells number, there was negative correlation (r=-.503, p<.05). However, between balance beam scores and BrdU-positive cells number, there was no correlation. In conclusion, the present study demonstrates that the role of swimming training improves behavioral motor function probably by enhancing cell proliferation in that hippocampus. This study provides a model for investigating the stroke rehabilitation that underlies neurogenesis and functional ability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.886-890
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• 2017

In this study, the protective effect of rice with Phellinus linteus mycelium (PLMR) against hydrogen peroxide-induced oxidative stress was assessed in a mouse hippocampal neuronal HT22 cell line through (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) salt (MTS) assay and western blot. MTS assay using HT22 cells showed that PLMR extract did not affect viability at a concentration range from 1 mg/mL to 5 mg/mL. However, at concentrations over 10 mg/mL, PLMR extract resulted in increased cell death. Cell viability of HT22 was significantly reduced by $H_2O_2$ treatment, and reduction of cell viability was efficiently restored by treatment with PLMR extract in a dose-dependent manner from 0.1 to 1 mg/mL. Cells treated with $H_2O_2$ showed increased expression of Bax, a pro-apoptotic protein, which was down-regulated by treatment with PLMR extract. On the other hand, cells treated with $H_2O_2$ resulted in reduced expression of Bcl-2, an anti-apoptotic protein, which was restored by treatment with PLMR extract. In addition, treatment with PLMR extract reduced expression of cleaved caspase 3 and PARP, which were up-regulated by $H_2O_2$ treatment. The results may suggest that treatment with PLMR extract would suppress $H_2O_2$-induced apoptosis of HT22 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.958-965
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• 2016

The objective of this study was to evaluate the antioxidant activity of green tea seed shell as an industrial byproduct. Green tea seed shell extract (GTSSE) was obtained by ethanol extraction, and the yield was $1.4{\pm}0.22%$. The radical scavenging activities [1,1-diphenyl-picrylhydrazyl and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)], xanthine oxidase inhibition activity, and reducing power of GTSSE dose-dependently increased. To estimate the neuroprotective effect of GTSSE, viability was tested in HT22 mouse hippocampal cells. GTSSE treatment induced cytotoxicity at a concentration higher than $100{\mu}g/mL$ but not at a concentration lower than $50{\mu}g/mL$. Using this optimal concentration range, GTSSE treatment significantly increased cell viability in $H_2O_2$-treated HT22 cells. Further, GTSSE treatment increased superoxide dismutase activity and decreased the malonaldehyde level, a product of lipid peroxidation, in HT22 cells. Therefore, these results indicate that green tea seed shell extract may be useful for the development of antioxidant materials and have potential activity to prevent and treat neuro-degenerative diseases such as Alzheimer's disease.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.430-441
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• 2023

Velvet antler is widely used as a traditional medicine, and numerous studies have demonstrated its tremendous nutritional and medicinal values including immunity-enhancing effects. This study aimed to investigate different deer velvet extracts (Sample 1: raw extract, Sample 2: dried extract, and Sample 3: freeze-dried extract) for proximate composition, uronic acid, sulfated glycosaminoglycan, sialic acid, collagen levels, and chemical components using ultra-performance liquid chromatography-quadrupole-time-of-light mass spectrometry. In addition, we evaluated the cytotoxic effect of the deer velvet extracts on BV2 microglia, HT22 hippocampal cells, HaCaT keratinocytes, and RAW264.7 macrophages using the cell viability MTT assay. Furthermore, we evaluated acute toxicity of the deer velvet extracts at different doses (0, 500, 1000, and 2000 mg/kg) administered orally to both male and female ICR mice for 14 d (five mice per group). After treatment, we evaluated general toxicity, survival rate, body weight changes, mortality, clinical signs, and necropsy findings in the experimental mice based on OECD guidelines. The results suggested that in vitro treatment with the evaluated extracts had no cytotoxic effect in HaCaT keratinocytes cells, whereas Sample-2 had a cytotoxic effect at 500 and 1000 ㎍/mL on HT22 hippocampal cells and RAW264.7 macrophages. Sample 3 was also cytotoxic at concentrations of 500 and 1000 ㎍/mL to RAW264.7 and BV2 microglial cells. However, the mice treated in vivo with the velvet extracts at doses of 500-2000 mg/kg BW showed no clinical signs, mortality, or necropsy findings, indicating that the LD50 is higher than this dosage. These findings indicate that there were no toxicological abnormalities connected with the deer velvet extract treatment in mice. However, further human and animal studies are needed before sufficient safety information is available to justify its use in humans.

• Korean Journal of Acupuncture
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• v.24 no.4
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• pp.99-110
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• 2007

Objectives : Epilepsy is one of the most common serious brain disorders that affect people of all ages, and it is characterized by recurrent unprovoked seizures. We examined whether acupuncture can reduce both the incidence of seizures and hippocampal cell death in dentate gyrus (DG) using a mouse model of kainic acid (KA)-induced epilepsy. Methods : ICR mice ($20{\sim}25$ g) were given acupuncture once a day at acupoint HT8 (sobu) bilaterally during 2 days before KA injection. After an intracerebroventricular injection of 0.1${\mu}g$ of KA, acupuncture treatment was subsequently administered once more (total 3 times), and the degree of seizure was observed for 20 min. Three hours after injection, we confirmed the neural cell death using cresyl violet staining and silver impregnation staining, and determined the expressions of c-Fos and glutamate decarboxylase (GAD)-67 using immunohistochemistry techniques in the DG. Results : KA induced epileptic seizure, neural cell death, increased c-Fos expression and decreased GAD-67 expression in the DG. Acupuncture treatment at HT8 reduced the severity of the epileptic seizure and inhibited neural cell death from KA. In addition, acupuncture normalized the expressions of c-Fos and GAD-67 in the same areas. Conclusions : These results demonstrated that acupuncture treatment at HT8 may reduce the KA-induced epileptic seizure and neural cell death in the DG possibly by normalizing c-Fos expressions and the gamma-aminobutyric acid neurons.

• Journal of Oriental Neuropsychiatry
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• v.22 no.2
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• pp.163-176
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• 2011

Objectives : BCS(Bambusae concretio silicae) is used as a traditional medicine in Korea for the incipient stroke. Recent reports indicated that BCS has a neuroprotective effect by anti-convulsion effect. However, it's mechanism is not well studied. The purpose of this study was to investigate into the molecular mechanism of BCS for neuroprotection in normoxia of cultured rat hippocampal neurons. Methods : BCS (1.0, 2.5, 5.0, and $10.0\;{\mu}g/m{\ell}$) was added to culture media (Neurobasal supplemented with B27) on DIV 0, given a normoxia, and the cell viability was measured by typical phase-contrast images of the cultures with 1.0, 2.5, 5.0, and $10.0\;{\mu}g/m{\ell}$ on DIV 21. Effects of BCS on the expression of various synaptic proteins ($GABA_B$ R1, $GABA_B$ R2, GlyR, PSD95) were observed by immunocytochemistry showing on DIV 3, 7 and 21. Results : Typical phase-contrast images of the cultures indicated that BCS has a protective effect of rat hippocampal cells in normoxia. The BCS upregulated $GABA_B$ R1 after normoxia on DIV 7, $GABA_A$ ${\beta}2/3$ on DIV 21 and $GABA_B$ R2 on DIV 21. And the BCS downregulated PSD95 after normoxia on DIV 7. Conclusions : The present study showed evidence for the efficacy of BCS in Typical phase-contrast images, upregulation of inhibitory neurotransmitter receptors($GABA_B$ R1) and downregulation of PSD95 which eventually protected neuronal cell death in normoxia.

• BMB Reports
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• v.49 no.7
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• pp.382-387
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• 2016

Reactive oxygen species generated under oxidative stress are involved in neuronal diseases, including ischemia. Glutathione S-transferase pi (GSTpi) is a member of the GST family and is known to play important roles in cell survival. We investigated the effect of GSTpi against oxidative stress-induced hippocampal HT-22 cell death, and its effects in an animal model of ischemic injury, using a cell-permeable PEP-1-GSTpi protein. PEP-1-GSTpi was transduced into HT-22 cells and significantly protected against H2O2-treated cell death by reducing the intracellular toxicity and regulating the signal pathways, including MAPK, Akt, Bax, and Bcl-2. PEP-1-GSTpi transduced into the hippocampus in animal brains, and markedly protected against neuronal cell death in an ischemic injury animal model. These results indicate that PEP-1-GSTpi acts as a regulator or an antioxidant to protect against oxidative stress-induced cell death. Our study suggests that PEP-1-GSTpi may have potential as a therapeutic agent for the treatment of ischemia and a variety of oxidative stress-related neuronal diseases.

• Journal of Life Science
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• v.30 no.6
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• pp.513-521
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• 2020

B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi1) is a polycomb group protein and a core component of polycomb repressive complex 1. Initial research into Bmi1 has focused on its role in tumorigenesis, and it is generally accepted that it is important for the proliferation and survival of cancer cells. However, more recent studies have revealed that Bmi1 is downregulated in brains with neurodegenerative disease and that it regulates the function of mitochondria and reactive oxygen species levels. In this study, we tested the therapeutic potential of Bmi1 in pilocarpine-induced seizures in Bmi1-knockout mice. Bmi1 expression transiently increased in the hippocampal CA1 and CA3 and the dentate gyrus following pilocarpine-induced status epilepticus (SE). In terms of seizure behavior, SE induction was 43.14% and 53.57% for Bmi1^+/+ and Bmi1^+/- mice, respectively. However, there was no significant difference in mortality or hippocampal damage between the two groups. Two months after SE induction, the frequency of epileptic seizures in the Bmi1^+/- mice was 50% lower than in the control group, although the difference was not statistically significant. In addition, mossy fiber outgrowth in the Bmi1^+/- mice was significantly higher than in their wild-type littermates. Taken together, these data indicate that reduced Bmi1 activity increases pilocarpine-induced seizure probability and mossy fiber outgrowth.