• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.39-47
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• 2010

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor involved in neuronal differentiation, plasticity, survival and regeneration. BDNF draws massive attention mainly due to the potential as a therapeutic target in neurological diseases such as depression and Alzheimer's disease. In a primary screening for the natural compounds enhancing BDNF release from cultured rat primary cortical neuron, we found that compounds such as baicalein, tanshinone IIa, cinnamic acid, epiberberine, genistein and wogonin among many others increased BDNF release. All the compounds at $0.1{\mu}M$ of concentration barely showed stimulatory effect on BDNF induction, however, their combination (mixture 1; baicalein, tanshinone IIa and cinnamic acid, mixture 2; epiberberine, genistein and wogonin) showed synergistic increase in BDNF release as well as mRNA and protein expression. The level of BDNF expression was comparable to the maximum BDNF stimulation attainable by a positive control oroxylin A ($20{\mu}M$) without cell toxicity as determined by MTT analysis. Both mixtures synergistically increased the phosphorylation of extracellular signal-regulated kinase (ERK) as well as cAMP response element binding protein (CREB), an immediate and essential regulator of BDNF expression. Similar to these results, mixture of these compounds synergistically inhibited the up-regulation of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide treatments in rat primary astrocytes. These results suggest that the combinatorial treatment of natural compounds in lower concentration might be a useful strategy to obtain sufficient BDNF stimulation in neurological disease condition such as depression, while minimizing potential side effects and toxicity of higher concentration of a single compound.

• Journal of Chest Surgery
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• v.49 no.4
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• pp.232-241
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• 2016

Background: Paraplegia is a devastating complication following operations on the thoracoabdominal aorta. We investigated whether histidine-tryptophan-ketoglutarate (HTK) solution could reduce the extent of ischemia/reperfusion (IR) spinal cord injuries in a rat model using a direct delivery method. Methods: Twenty-four Sprague-Dawley male rats were randomly divided into four groups. The sham group (n=6) underwent a sham operation, the IR group (n=6) underwent only an aortic occlusion, the saline infusion group (saline group, n=6) underwent an aortic occlusion and direct infusion of cold saline into the occluded aortic segment, and the HTK infusion group (HTK group, n=6) underwent an aortic occlusion and direct infusion of cold HTK solution into the occluded aortic segment. An IR spinal cord injury was induced by transabdominal clamping of the aorta distally to the left renal artery and proximally to the aortic bifurcation for 60 minutes. A neurological evaluation of locomotor function was performed using the modified Tarlov score after 48 hours of reperfusion. The spinal cord was harvested for histopathological and immunohistochemical examinations. Results: The spinal cord IR model using direct drug delivery in rats was highly reproducible. The Tarlov score was 4.0 in the sham group, $1.17{\pm}0.75$ in the IR group, $1.33{\pm}1.03$ in the saline group, and $2.67{\pm}0.81$ in the HTK group (p=0.04). The histopathological analysis of the HTK group showed reduced neuronal cell death. Conclusion: Direct infusion of cold HTK solution into the occluded aortic segment may reduce the extent of spinal cord injuries in an IR model in rats.

• IMMUNE NETWORK
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• v.6 no.1
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• pp.27-32
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• 2006

Background: Chronic inflammation in the brain has known to be associated with the development of a various neurological diseases including dementia. In general, the characteristic of neuro-inflammation is the activated microglia over the brain where the pathogenesis occurs. Pro-inflammatory repertoires, interleukin-1${\beta}$ (IL-1${\beta}$) and nitric oxide (NO), are the main causes of neuro-degenerative disease, particularly in Alzheimer's disease (AD) which is caused by neuronal destruction. Those pro-inflammatory repertoires may lead the brain to chronic inflammatory status, and thus we hypothesized that chronic inflammation would be inhibited when pro-inflammatory repertoires are to be well controlled by inactivating the signal transduction associated with inflammation. Methods: In the present study, we examined whether biphenyl dimethyl dicarboxylate (DDB), an active compound from Schizandra chinensis Baillon, inhibits the NO production by a direct method using Griess reagent and by RT-PCR in the gene expression of inducible nitric oxide synthase (iNOS) and IL-1${\beta}$. Western blots were also used for the analysis of NF-${\kappa}B$ and I${\kappa}B$. Results: In the study, we found that DDB effectively inhibited IL-1${\beta}$ as well as NO production in BV-2 microglial cell, and the translocation of NF-${\kappa}B$ was comparably inhibited in the presence of DDB comparing those to the positive control, lipopolysaccharide. Conclusion: The data suggested that the DDB from Schizandra chinensis Baillon may play an effective role in inhibiting the pro-inflammatory repertoires which may cause neurodegeneration and the results imply that the compound suppresses a cue signal of the microglial activation which can induce the brain pathogenesis such as Alzheimer's disease.

• Journal of Acupuncture Research
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• v.33 no.4
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• pp.49-63
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• 2016

Objectives : This research was performed to investigate the effects of Jodeungsan pharmacopuncture(PA-J) of focal brain ischemia induced by middle cerebral artery occlusion(MCAO) in rats. Methods : The subjects were divided into 4 groups : control, acupuncture, pharmacopuncture PA-J1(11.43 mg / 250 g / $40{\mu}{\ell}$) and pharmacopuncture PA-J2(2.29 mg / 250 g / $40{\mu}{\ell}$). The focal brain ischemia was induced by intraluminal filament insertion into the middle cerebral artery. After 3 days of MCAO, Jodeungsan pharmacopuncture treatment was performed on the GB20, and the day after being treated with pharmacopuncture, the Morris water maze test was carried out on the assigned group. The series of processes were administered 6 times. Thereafter mGluR5, density of neuronal cell and ChAT were measured. Results : The results were as follows. 1. The distance to target significantly decreased in the 2nd trial of the Acu group on the water maze test for short-term memory. 2. The distance to target significantly decreased in the 4th trial of the PA-J2 group on the water maze test for long-term memory. 3. The intensity of mGluR5 significantly increased in the PA-J1 group compared with the control group. 4. The neuroprotective effect on the hippocampal CA1 significantly increased in the PA-J1 and PA-J2 groups compared with the control group. 5. The density of ChAT in the hippocampal CA1 significantly increased in the PA-J1 and PA-J2 groups compared with the control group. Conclusion : These results suggest that Jodeungsan pharmacopuncture may improve memory and cognitive impairment and also have neuroprotective effects on focal brain ischemia.

• Biomolecules & Therapeutics
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• v.22 no.1
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• pp.17-26
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• 2014

${\alpha}$-Asarone exhibits a number of pharmacological actions including neuroprotective, anti-oxidative, anticonvulsive, and cognitive enhancing action. The present study investigated the effects of ${\alpha}$-asarone on pro-inflammatory cytokines mRNA, microglial activation, and neuronal damage in the hippocampus and on learning and memory deficits in systemic lipopolysaccharide (LPS)-treated C57BL/6 mice. Varying doses of ${\alpha}$-asarone was orally administered (7.5, 15, or 30 mg/kg) once a day for 3 days before the LPS (3 mg/kg) injection. ${\alpha}$-Asarone significantly reduced TNF-${\alpha}$ and IL-$1{\beta}$ mRNA at 4 and 24 hours after the LPS injection at dose of 30 mg/kg. At 24 hours after the LPS injection, the loss of CA1 neurons, the increase of TUNEL-labeled cells, and the up-regulation of BACE1 expression in the hippocampus were attenuated by 30 mg/kg of ${\alpha}$-asarone treatment. ${\alpha}$-Asarone significantly reduced Iba1 protein expression in the hippocampal tissue at a dose of 30 mg/kg. ${\alpha}$-Asarone did not reduce the number of Iba1-expressing microglia on immunohistochemistry but the average cell size and percentage areas of Iba1-expressing microglia in the hippocampus were significantly decreased by 30 mg/kg of ${\alpha}$-asarone treatment. In the Morris water maze test, ${\alpha}$-asarone significantly prolonged the swimming time spent in the target and peri-target zones. ${\alpha}$-Asarone also significantly increased the number of target heading and memory score in the Morris water maze. The results suggest that inhibition of pro-inflammatory cytokines and microglial activation in the hippocampus by ${\alpha}$-asarone may be one of the mechanisms for the ${\alpha}$-asarone-mediated ameliorating effect on memory deficits.

• Journal of Life Science
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• v.18 no.12
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• pp.1631-1636
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• 2008

Rhei Rhizoma (RR; 大黃) consists of the underground parts (rhizome and root) of Rheum officinale Baill. and Rheum palmatum L. (Polygonaceae), and is widely used in Southeast Asian folk medicine to alleviate liver and kidney damages. In this study, we investigated into the efficacy and mechanism of RR water extract in supporting neuronal survival in a hypoxia model of cultured rat hippocampal neurons. RR exhibited no cytotoxicity up to 10 ${\mu}g$/ml and exhibited neurosupportive effects at 2.5 ${\mu}g$/ml in normoxia. When RR was added to the culture media on 10 days in vitro (DIV10) and given a hypoxic shock (2% $O_2$/5% $CO_2$, 3 hr, $37^{\circ}C$) on DIV13, RR exhibited neuroprotective effects on 5 days post-shock. $H_2DCF$ stainings indicated that RR effectively prevents ROS production in both normoxia and hypoxia. JC-1 stainings showed that RR prevents dissipation of MMP in hypoxia. These results indicate that RR protects neurons by suppressing ROS production and MMP loss.

• Toxicological Research
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• v.31 no.2
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• pp.157-163
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• 2015

Nanotechnology has advanced at an extremely rapid pace over the past several years in numerous fields of research. However, the uptake of nanoparticles (NPs) into the body after administration through various routes may pose a risk to human health. In this study, we investigated the potential ocular toxicity of 20-nm, negatively- charged zinc oxide (ZnO) NPs in rats using micro-computed tomography (micro-CT) and histopathological assessment. Animals were divided into four groups as control group, ZnO NPs treatment group (500 mg/kg/day), control recovery group, and ZnO NPs treatment and recovery group. Ocular samples were prepared from animals treated for 90 days (10 males and 10 females, respectively) and from recovery animals (5 males and 5 females, respectively) sacrificed at 14 days after final treatment and were compared to age-matched control animals. Micro-CT analyses represented the deposition and distribution of foreign materials in the eyes of rats treated with ZnO NPs, whereas control animals showed no such findings. X-ray fluorescence spectrometry and energy dispersive spectrometry showed the intraocular foreign materials as zinc in treated rats, whereas control animals showed no zinc signal. Histopathological examination revealed the retinopathy in the eyes of rats treated with ZnO NPs. Neuronal nuclei expression was decreased in neurons of the ganglion cell layer of animals treated with ZnO NPs compared to the control group. Taken together, treatment with 20-nm, negatively-charged ZnO NPs increased retinopathy, associated with local distribution of them in ocular lesions.

• Applied Microscopy
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• v.41 no.4
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• pp.249-255
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• 2011

Neurons utilize a large quantity of energy for their survival and function, and thereby require active mitochondrial function. Mitochondrial morphology shows dynamic changes, depending on the cellular condition, and mitochondrial dynamics are required for neuronal development and function. In this study, we found that the length of mitochondria in the distal axon is significantly shorter than that of mitochondria in dendrites or proximal axons of cerebral cortical neurons, and the reason for this difference is the local fission within the axon. We also found that suppression of Drp1, a key regulator of mitochondrial fission, resulted in significant elongation of mitochondria in axons. Collectively, these results suggest that local mitochondrial fission within the axon contributes to region-dependent mitochondrial length differences in the axons of cortical neurons.

• Journal of Life Science
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• v.28 no.10
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• pp.1140-1146
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• 2018

Dual-specificity phosphatases (DUSPs) play a role in cell growth and differentiation by modulating mitogen-activated protein kinases. DUSPs are considered targets for drugs against cancers, diabetes, immune diseases, and neuronal diseases. Part of the DUSP family, DUSP19 modulates c-Jun N-terminal kinase activity and is involved in osteoarthritis pathogenesis. Here, we report screening of cavity-creating mutants and the crystal structure of a cavity-creating L75A mutant of DUSP19 which has significantly enhanced enzyme activity in comparison to the wild-type protein. The crystal structure reveals a well-formed cavity due to the absent Leu75 side chain and a rotation of the active site-bound sulfate ion. Despite the cavity creation, residues surrounding the cavity did not rearrange significantly. Instead, a tightened hydrophobic interaction by a remote tryptophan residue was observed, indicating that the protein folding of the L75A mutant is stabilized by global folding energy minimization, not by local rearrangements in the cavity region. Conformation of the rotated active site sulfate ion resembles that of the phosphor-tyrosine substrate, indicating that cavity creation induces an optimal active site conformation. The activity enhancement by an internal cavity and its structural information provide insight on allosteric modulation of DUSP19 activity and development of therapeutics.

• Applied Microscopy
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• v.29 no.1
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• pp.57-66
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• 1999

The nervous tissue in the cerebral ganglion of Korean planaria was observed using electron microscope. The obtained results are as follows: A cerebral ganglion is composed of the nerve cells, neurosecretory cells, neuroglial cells and neuropils. The nerve cells are round or ovoidal-shaped cells (diameter, $5{\mu}m$), which has a large ellipsoidal nucleus containing the evenly developed heterochromatin. Their cytoplasms were found to be relatively simple, because of their undeveloped cell organelles. The neurosecretory cells are long and ellipsoid or spindle-shaped cells, where there were found a large ellipsoidal nucleus and cytoplasm filled with secretory granules (diameter, 60 nm). The neuroglial cells were seldom observed. They are spindle-shaped cells (size, $6\times0.8{\mu}m$), which were observed mainly among the nerve fibers. The neuropils are formed by the nerve fibers and nerve endings which are filled with mitochondria, neurotubules and secretory granules of four kinds (high electron dense granules of sizes 75 nm, 50 nm and 37 nm, and electron lucent granule of size 30 nm etc.). These granular vesicles are divided into single vesicle type and compound vesicle type in the nerve terminals, and neuronal synapses were observed to be the axo-dendritic and dendro-dendritic synapse type.