• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.31-39
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• 2008

손상된 뇌신경조직내에서 신경줄기세포로부터 새로운 신경세포로의 분화가 상당히 제한되어 있어 이것이 손상된 뇌신경조직의 복구가 잘 이루어지지 않는 원인이라 여겨지고 있다. 본 연구에서는 세포배양을 통해 지방조직 중간엽 줄기세포를 도파민성 신경세포와 콜린성 신경세포로 분화를 유도하였다. 중간엽 줄기세포를 신경세포로 분화시키기 위해 N2배양액에 bFGF, EGF, dimethyl sulphoxide (DMSO)와 butylated hydroxyanisole (BHA)를 첨가하여 유도하였다. DMSO와 BHA에 처리된 중간엽 줄기세포가 빠르게 신경세포 모양으로 분화하는 것을 관찰하였으며, 이것은 면역조직학적 염색에서 신경세포 특이 표지인 $\beta$-tubulin III, 별아교세포에 대한 특이 표지인 GFAP, 흰돌기아교세포에 대한 특이 표지인 Gal-C에 대해 양성반응을 나타내었다. RT-PCR 분석에서 배양 단계에 따라 신경세포에 특이적인 표지 인자인 neuro D1, $\beta$-tubulin III, GFAP, nestin 등의 발현을 통해, 중간엽 줄기세포가 신경세포로 분화됨을 확인하였다. 그러나 중간엽줄기세포가 신경세포로 분화된 이후에는 줄기세포 표지인 SCF, C-kit와 stat-3 등은 발현되지 않았다. 또한, 중간엽줄기세포에 bFGF, SHH와 FGF8 등을 처리하면 도파민 신경세포로 분화하였다. 중간엽 줄기세포에 bFGF, RA, Shh를 처리하여 콜린성 신경세포로 분화시켰을 때, 신경세포 특이 표지인 $\beta$-tubulin III와 콜린성 신경 특이 표지인 ChAT에 양성반응를 보였다. 결론적으로 사람 지방조직의 중간엽 줄기세포가 도파민성과 콜린성 신경세포로 분화가 가능하고 이러한 잠재성을 가진 지방 유래 중간엽 줄기세포는 퇴행성 신경질환에 대한 세포 치료제로서 가능성을 제시한다.

• BMB Reports
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• 제28권4호
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• pp.323-330
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• 1995

Recent studies have shown that dopamine applied to cultured swimming motor neurons of Polyorchis penicillatus produces an inhibitory action by opening potassium channels through $D_2$-like receptors. In this study, it was demonstrated that dopamine found in the hydromedusa was not from exogenous sources and the content of dopamine depended on the $Ca^{2+}$ content of the dissecting media. In addition, a combination of thin layer chromatography and high performance liquid chromatography showed the presence of DOPA and DO PAC-like compounds in the jellyfish. The glyoxylic acid method for catecholamines suggested that a population of small cells, neither swimming motor neurons nor B-like neurons, had dopaminergic systems. From all these results, it is suggested here that DA synthesized from DOPA in some cells is released. being dependent on calcium concentrations, into a synaptic cleft and degraded into DOPAC after acting as an inhibitory transmitter to swimming motor neurons.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2005년도 춘계학술대회
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• pp.53-60
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• 2005

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting $1\%$ of the population above the age of 65 and is characterized by a selective loss of dopaminergic neurons in the substantia nigra pars compacta. Although the underlying cause of dopaminergic cell death or the mechanism by which these cells degenerate is still not clearly understood, oxidative stress, mitochondrial dysfunction, and protein misfolding are thought to play important roles in the dopaminergic degeneration in PD. Tetrahydrobiopterin (BH4) is synthesized exclusively in the monoaminergic, including dopaminergic, cells and serves as an endogenous and obligatory cofactor for syntheses of the potential oxidative stressors dopamine and nitric oxide. In addition to its contribution toward the syntheses of these two potentially toxic molecules, BH4 itself can directly generate oxidative stress. BH4 undergoes oxidation during the hydroxylation reaction as well as nonenzymatic autooxidation to produce hydrogen peroxide and superoxide radical. We have previously suggested BH4 as an endogenous molecule responsible for the dopaminergic neurodegeneration. BH4 exerts selective toxicity to dopamine-producing cells via generation of oxidative stress, mitochondrial dysfunction, and apoptosis. BH4 also induces morphological, biochemical, and behavioral characteristics associated with PD in vivo. BH4 as well as enzyme activity and gene expression of GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis pathway, are readily upregulated by cellular changes such as calcium influx and by various stimuli including stress situations. This points to the possibility that cellular availability of BH4 might be increased in aberrant conditions, leading to increased extracellular BH4 subsequent degeneration. The fact that BH4 is specifically and endogenously synthesized in dopaminergic cells, Is readily upregulated, and generates oxidative stress-related cell death provides physical relevance of this molecule as an attractive candidate with which to explain the mechanism of pathogenesis of PD.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제48차 춘계 학술대회
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• pp.116.2-117
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• 2005

• The Korean Journal of Physiology and Pharmacology
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• 제28권2호
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• pp.165-181
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• 2024

The slow and regular pacemaking activity of midbrain dopamine (DA) neurons requires proper spatial organization of the excitable elements between the soma and dendritic compartments, but the somatodendritic organization is not clear. Here, we show that the dynamic interaction between the soma and multiple proximal dendritic compartments (PDCs) generates the slow pacemaking activity in DA neurons. In multipolar DA neurons, spontaneous action potentials (sAPs) consistently originate from the axon-bearing dendrite. However, when the axon initial segment was disabled, sAPs emerge randomly from various primary PDCs, indicating that multiple PDCs drive pacemaking. Ca²⁺ measurements and local stimulation/perturbation experiments suggest that the soma serves as a stably-oscillating inertial compartment, while multiple PDCs exhibit stochastic fluctuations and high excitability. Despite the stochastic and excitable nature of PDCs, their activities are balanced by the large centrally-connected inertial soma, resulting in the slow synchronized pacemaking rhythm. Furthermore, our electrophysiological experiments indicate that the soma and PDCs, with distinct characteristics, play different roles in glutamate-induced burst-pause firing patterns. Excitable PDCs mediate excitatory burst responses to glutamate, while the large inertial soma determines inhibitory pause responses to glutamate. Therefore, we could conclude that this somatodendritic organization serves as a common foundation for both pacemaker activity and evoked firing patterns in midbrain DA neurons.

• 생약학회지
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• 제40권1호
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• pp.41-45
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• 2009

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzhemier's disease. Neuropathologically, PD is characterized by the selective loss of dopaminergic neurons. The neuronal toxicity of cytosolic excess dopamine (DA) has been described in many studies using several cell lines. In dopaminergic neurons, cytosolic excess DA is easily oxidized via monoamine oxidase (MAO)-B, tyrosinase or by auto-oxidation to produce neurotoxic metabolites such as DA quinone. So, in the present study, we induced cell death by treatment of DA ($600{\mu}M$) in human neuroblastoma SH-SY5Y cell which was treated samples before 24 hr, and cell viability was measured by fluorescence activated cell sorter (FACs) analysis. Of those tested, the extracts of Poria cocos (赤茯笭)(whole), Gastrodia elata (rhizomes), Eucommia ulmoides (炒)(barks), Syneilesis palmata (whole), Acorus gramineus (rhizomes), Ligustrum japonicum (leaves) showed neuroprotective effects in dose dependent manner.

• Clinical and Experimental Reproductive Medicine
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• 제31권1호
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• pp.19-27
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• 2004

Objective: This study was to examine the in vitro neural cell differentiation patterns of human embryonic stem (hES) cells following treatment of various neurotrophic factors [basic fibroblast growth factor (bFGF), retinoic acid (RA), brain derived neurotrophic factor (BDNF) and transforming growth factor (TGF)-$\alpha$], particulary in dopaminergic neuron formation. Methods: The hES cells were induced to differentiate by bFGF and RA. Group I) In bFGF induction method, embryoid bodies (EBs, for 4 days) derived from hES were plated onto gelatin dish, selected for 8 days in ITSFn medium and expanded at the presence of bFGF (10 ng/ml) for another 6 days followed by a final differentiation in N2 medium for 7, 14 and 21 days. Group II) For RA induction, EBs were exposed of RA ($10^{-6}M$) for 4 days and allowed to differentiate in N2 medium for 7, 14 and 21 days. Group III) To examine the effects of additional neurotrophic factors, bFGF or RA induced cells were exposed to either BDNF (10 ng/ml) or TGF-$\alpha$ (10 ng/ml) during the 21 days of final differentiation. Neuron differentiation and dopamine secretion were examined by indirect immunocytochemistry and HPLC, respectively. Results: The bFGF or RA treated hES cells were resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with BDNF or TGF-$\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression of a dopaminergic neuron marker, compared to control (p<0.05). In contrast, no effect was observed on the rate of mature neuron (NF-200) or glutamic acid decarboxylase-positive neurons. Immunocytochemistry and HPLC analyses revealed the higher levels of TH expression (20.3%) and dopamine secretion (265.5 $\pm$ 62.8 pmol/mg) in bFGF and TGF-sequentially treated hES cells than those in $\alpha$ RA or BDNF treated hES cells. Conclusion: These results indicate that the generation of dopamine secretory neurons from in vitro differentiated hES cells can be improved by TGF-$\alpha$ addition in the bFGF induction protocol.

• Korean Journal of Acupuncture
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• 제40권3호
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• pp.90-98
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• 2023

Objectives : Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide and is characterized by the loss of the dopaminergic neurons in the substantia nigra (SN). In a previous in vitro study, we demonstrated that Sihogyeji-tang (SG), Sihosogan-tang (SS), and Sihocheonggan-tang (SC) have the potential to be candidate medicines for PD. This study aimed to compare the neuroprotective effect of SG, SS, and SC using 1-methyl-4-phenyl-1,2,3,6-tetrahydrophridine (MPTP)-induced PD mouse model. Methods : Eight-week-old male C57BL/6 mice were intraperitoneally administered with 30 mg/kg of MPTP for 5 days and orally administered SG, SS and SC for 12 days from the first MPTP injection. Motor function was assessed using the pole test and the rotarod test. Dopaminergic neuronal survival in the SN and striatum was evaluated through tyrosine-hydroxylase immunohistochemistry. Results : MPTP administration resulted in behavioral impairment and dopaminergic neuronal death in the SN and striatum. In the pole test, treatment with SG, SS, and SC alleviated the MPTP-induced motor dysfunction on day 5 and 12. In the rotarod test, SS and SG alleviated the MPTP-induced motor dysfunction on day 5, while only SS showed improvement on day 12. SS and SG significantly protected dopaminergic neurons in the SN from MPTP toxicity, and all three compounds (SG, SS, and SC) showed significant protection in the striatum. Notably, SS demonstrated superior efficacy in suppressing MPTP-induced motor dysfunction and dopaminergic neuronal death compared to SG and SC. Conclusions : These findings suggest that SS is the most effective formula among SG, SS, and SC for PD, indicating its potential role in the treatment of PD.

• 동의신경정신과학회지
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• 제20권1호
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• pp.21-42
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• 2009

Objectives : This Study was performed to assess the antioxidant and neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells and primary rat mesencephalic dopaminergic neurons. Methods : The anioxidant effect was investigated using the DPPH radical and ABTS cation scavenging assays and total polyphenol amout of Chunghyul-dan(Qingxuedan). The neuroprotective effect of Chunghyul-dan(Qingxuedan) in PC12 cells was evaluated using MTT assay. The scavenging activity of Chunghyul-dan(Qingxuedan) on ROS production induced by 6-OHDA(6-hydroxydopamine) in PC12 cells was evaluated, as well as the attenuating effect on GSH reduction. Finally, we examined the neuroprotective effect of Chunghyul-dan(Qingxuedan) against 6-0HDA-induced toxicity in the primary culture of rat mesencephalic doperminergic neurons. Results : Chunghyul-dan(Qingxuedan) showed concentration-dependent scavenging activities in DPPH radical and ABTS cation scavenging assays and it was not cytotoxic to PC12 cells. In postand co-treatment, Chunghyul-dan(Qingxuedan) protected PC12 cells from the 6-OHDA induced toxicity at 50 and 100 ${\mu}$g/mL significantly. And Chunghyu!-dan(Qingxuedan) decreased the 6-OHDA induced ROS production at a dose dependent manner, while increaing the 6-OHDA induced GSH reduction at 50 and 100 ${\mu}$g/mL significantly. Finally, Chunghyul-dan(Qingxuedan) showed signicant protection of rat mescencephalic dopaminergic neurons from 6-OHDA at 1 ${\mu}$g/mL. Conclusions : These results demonstrate that Chunghyul-dan(Qingxuedan) has the antioxidant and neuroprotective effect against 6-0HDA induced cytotoxicity through decreasing ROS production and increasing GSH reduction.

• 대한한의학회지
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• 제30권4호
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• pp.79-92
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• 2009

Objectives: The aim of the present study was to explore the neuroprotective effect and the possible mechanism of the PD-1 extracts on 1-methyl-4-phenyl-1,2,3,6-tetrahydrophridine (MPTP)-lesioned C57BL/6 mouse model of Parkinson's disease (PD). Methods: The mice were supplemented (or not) with 50 or 100 mg/kg/day of PD-1 for 2 weeks, after which MPTP was injected intraperitoneally. We observed that daily administration of PD-1 prevented MPTP-induced depletion of striatal DA, and maintained striatal and nigral tyrosine hydroxylase (TH) protein levels. Results: Our results demonstrated that mice treated with PD-1 prior to MPTP administration showed more abundant TH-immunopositive (TH-ir) fibers and neurons than mice given only MPTP, indicating that PD-1 protects dopaminergic striatal fibers and nigral neurons from MPTP insults. Possible neuroprotective effect of PD-1 was further studied by the detection of antiapoptotic protein (bcl-2) and proapoptotic protein (Bax). In this assay, MPTP elevated the Bax protein and decreased the bcl-2 protein, while these expressions were prevented by PD-1 pre-treatment. Conclusions: The present results suggest that PD-1 is able to protect dopaminergic neurons from MPTP-induced neuronal injury with anti-apoptotic activity being one of the possible mechanisms.