• Biomolecules & Therapeutics
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• 제18권1호
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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.

• Applied Microscopy
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• 제31권2호
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• pp.167-173
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• 2001

한국재래산양의 임신60, 90, 105, 120일령 태아 및 신생아의 뇌를 대상으로 면역조직화학적방법을 통하여 면역반응을 나타낸 방사아교세포를 투과전자현미경적 방법을 이용하여 그 미세구조를 연구한 결과 임신 60일령 태아의 방사아교면역반응세포는 소수의 사립체와 많은 당원질 및 과립형질내세망이 관찰되었으며 임신90일령 태아 이후에서도 소수의 사립체, 많은 당원질 그리고 소수의 형질내세망이 관찰되었으며 임신95일령 태아에서 골지체가 관찰되었다. 그리고 임신 120일령에서 혈관에 부착되어 종말발을 뻗고 있는 GFAP 면역반응세포를 관찰할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제16권6호
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• pp.405-411
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• 2012

The spontaneous axon regeneration of damaged neurons is limited after spinal cord injury (SCI). Recently, mesenchymal stem cell (MSC) transplantation was proposed as a potential approach for enhancing nerve regeneration that avoids the ethical issues associated with embryonic stem cell transplantation. As SCI is a complex pathological entity, the treatment of SCI requires a multipronged approach. The purpose of the present study was to investigate the functional recovery and therapeutic potential of human MSCs (hMSCs) and polymer in a spinal cord hemisection injury model. Rats were subjected to hemisection injuries and then divided into three groups. Two groups of rats underwent partial thoracic hemisection injury followed by implantation of either polymer only or polymer with hMSCs. Another hemisection-only group was used as a control. Behavioral, electrophysiological and immunohistochemical studies were performed on all rats. The functional recovery was significantly improved in the polymer with hMSC-transplanted group as compared with control at five weeks after transplantation. The results of electrophysiologic study demonstrated that the latency of somatosensory-evoked potentials (SSEPs) in the polymer with hMSC-transplanted group was significantly shorter than in the hemisection-only control group. In the results of immunohistochemical study, ${\beta}$-gal-positive cells were observed in the injured and adjacent sites after hMSC transplantation. Surviving hMSCs differentiated into various cell types such as neurons, astrocytes and oligodendrocytes. These data suggest that hMSC transplantation with polymer may play an important role in functional recovery and axonal regeneration after SCI, and may be a potential therapeutic strategy for SCI.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.8.1-8.14
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• 2018

We previously demonstrated that the direct transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) into the dentate gyrus ameliorated the neurological symptoms of Niemann-Pick type C1 (NPC1)-mutant mice. However, the clinical presentation of NPC1-mutant mice was not fully understood with a molecular mechanism. Here, we found 14,15-epoxyeicosatrienoic acid (14,15-EET), a cytochrome P450 (CYP) metabolite, from hUCB-MSCs and the cerebella of NPC1-mutant mice and investigated the functional consequence of this metabolite. Our screening of the CYP2J family indicated a dysregulation in the CYP system in a cerebellar-specific manner. Moreover, in Purkinje cells, CYP2J6 showed an elevated expression level compared to that of astrocytes, granule cells, and microglia. In this regard, we found that one CYP metabolite, 14,15-EET, acts as a key mediator in ameliorating cholesterol accumulation. In confirming this hypothesis, 14,15-EET treatment reduced the accumulation of cholesterol in human NPC1 patient-derived fibroblasts in vitro by suppressing cholesterol synthesis and ameliorating the impaired autophagic flux. We show that the reduced activity within the CYP system in the cerebellum could cause the neurological symptoms of NPC1 patients, as 14,15-EET treatment significantly rescued cholesterol accumulation and impaired autophagy. We also provide evidence that the intranasal administration of hUCB-MSCs is a highly promising alternative to traumatic surgical transplantation for NPC1 patients.

• Biomolecules & Therapeutics
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• 제29권3호
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• pp.321-330
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• 2021

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H2O2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

• 생명과학회지
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• 제28권12호
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• pp.1397-1405
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• 2018

미토콘드리아는 세포안에서 에너지 공급, 칼슘 이온 저장, 활성산소 생성, 세포 자살과 같은 다양한 기능을 수행한다. 이러한 기능을 통해, 미토콘드리아는 줄기세포의 유지, 증식, 그리고 분화에 관여한다. 뇌에서 뇌실 하 영역(subventricular zone, SVZ)에는 일평생 새로운 신경세포를 생성하는 신경줄기세포(neural stem cell, NSC)가 존재한다. 하지만, SVZ NSCs에서 미토콘드리아의 역할에 대한 연구는 많이 알려져 있지 않다. 이번 연구에서 우리는 미토콘드리아의 complex I 저해제인 rotenone이 SVZ NSCs의 증식과 분화를 다른 방식으로 방해한다는 것을 보여주었다. 증식 중인 신경줄기세포에서, rotenone은 세포분열을 감소시켰는데, 이때 세포분열은 히스톤 H3에 인산기가 붙어있는 지를 측정하여 확인하였다. Rotenone을 50 nM 농도로 증식 중인 신경줄기세포에 처리했을 때, 세포사멸은 발생하지 않았다. 한편, 분화 중인 신경줄기세포에 rotenone을 처리한 경우, 신경세포와 희소 돌기아교 세포(oligodendrocyte)으로의 분화가 억제되었고, glial fibrillary acidic protein (GFAP)를 발현하는 성상세포(astrocyte)에는 영향이 없었다. 흥미롭게도, 4-6일 동안의 분화 과정 동안 rotenone이 처리된 신경줄기세포에서 대조군 보다 더 많은 세포 수가 관찰 되었는데, 이는 증식 과정 중의 rotenone의 효과와 다른 것이다. 이에, 우리는 rotenone이 세포 자살은 감소시켰으나, 세포 분열에는 영향을 끼치지 않았음을 관찰하였다. 세포 자살의 경우는 cleaved caspase-3를 측정함으로써 확인하였다. 이러한 결과들은 SVZ 신경줄기세포의 증식과 분화 모두에 제대로 작동하는 미토콘드리아가 있어야 함을 제안하고 있다. 게다가, 이러한 과정에서 미토콘드리아는 세포 분열과 세포자살에 관여할 수도 있을 것이다.

• 생명과학회지
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• 제31권2호
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• pp.237-247
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• 2021

신경염증(neuroinflammation)은 여러 신경 질환의 원인 인자로 확인되고있다. 중추 신경계에 발현되는 단백질 복합체인 NLRP3 인플라마좀은 미생물, 응집되고 잘못 접힌 단백질, ATP와 같은 광범위한 외인성 및 내인성 자극에 의해 감지되고 캐스페이즈-1(capase-1)을 활성화할 수 있다. 활성을 띠는 캐스페이즈-1은 IL-1b와 IL-18과 같은 염증성 사이토카인(pro-inflammatory cytokine)을 활성화시키고 급속한 세포사멸(파이롭토시스, pyroptosis)를 야기한다. IL-1b와 IL-18, 그리고 파이롭토시스를 통해 분비된 DAMPs은 다양한 신호 전달 경로를 통해 신경염증 반응을 유도하여 신경 손상을 유발한다. 따라서 NLRP3 인플라마좀은 신경염증으로 인한 여러 가지 신경질환 발병에 중요한 역할을 할 것으로 여겨진다. 본 리뷰 에서는 NLRP3 인플라마좀의 구조와 활성화에 대해 간략히 알아 보고 다양한 형태의 신경 질환에서 NLRP3 인플라마좀의 역할에 대해 논의하고자 한다.

• Journal of Korean Neurosurgical Society
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• 제65권6호
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• pp.790-800
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• 2022

Objective : EID3 (EP300-interacting inhibitor of differentiation) was identified as a novel member of EID family and plays a pivotal role in colorectal cancer development. However, its role in glioma remained elusive. In current study, we identified EID3 as a novel oncogenic molecule in human glioma and is critical for glioma cell survival, proliferation and invasion. Methods : A total of five patients with glioma were recruited in present study and fresh glioma samples were removed from patients. Four weeks old male non-obese diabetic severe combined immune deficiency (NOD/SCID) mice were used as transplant recipient models. The subcutaneous tumor size was calculated and recorded every week with vernier caliper. EID3 and AMP-activated protein kinase α1 (AMPKα1) expression levels were confirmed by real-time polymerase chain reaction and Western blot assays. Colony formation assays were performed to evaluate cell proliferation. Methyl thiazolyl tetrazolium (MTT) assays were performed for cell viability assessment. Trypan blue staining approach was applied for cell death assessment. Cell Apoptosis DNA ELISA Detection Kit was used for apoptosis assessment. Results : EID3 was preferentially expressed in glioma tissues/cells, while undetectable in astrocytes, neuronal cells, or normal brain tissues. EID3 knocking down significantly hindered glioma cell proliferation and invasion, as well as induced reduction of cell viability, apoptosis and cell death. EID3 knocking down also greatly inhibited tumor growth in SCID mice. Knocking down of AMPKα1 could effectively rescue glioma cells from apoptosis and cell death caused by EID3 absence, indicating that AMPKα1 acted as a key downstream regulator of EID3 and mediated suppression effects caused by EID3 knocking down inhibition. These findings were confirmed in glioma cells generated patient-derived xenograft models. AMPKα1 protein levels were affected by MG132 treatment in glioma, which suggested EID3 might down regulate AMPKα1 through protein degradation. Conclusion : Collectively, our study demonstrated that EID3 promoted glioma cell proliferation and survival by inhibiting AMPKα1 expression. Targeting EID3 might represent a promising strategy for treating glioma.

• 대한본초학회지
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• 제36권6호
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• pp.1-8
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• 2021

Objectives : Atractylodis rhizoma Alba has been traditionally used as a medicinal resource that is used for enhancing Qi (氣) in traditional medicine in Korea, China, and Japan. This study investigated the protective effects of Atractylodis rhizoma Alba extract (ARE) against trimethyltin (TMT), a neurotoxin that causes selective hippocampal injury, using both in vitro and in vivo models. Methods : We investigated the effects of ARE on TMT- (5mM) induced cytotoxicity in primary cultures of mouse hippocampal cells (7 days in vitro ) and on hippocampal injury in C57BL/6 mice injected with TMT (2.6 mg/kg). Results : We observed that ARE treatment (0 - 50 ㎍/mL) significantly reduced TMT-induced cytotoxicity in cultured hippocampal neurons in a dose-dependent manner, based on results of lactate dehydrogenase and 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays. Additionally, this study showed that orally administered ARE (5 mg/kg; between -6 and 0 days before TMT injection) significantly attenuated seizures in adult mice. Furthermore, quantitative analysis of allograft inflammatory factor-1 (Iba-1)- and glial fibrillary acidic protein (GFAP)- positive cells showed significantly reduced levels of Iba-1- and GFAP-positive cell bodies in the dentate gyrus of mice treated with ARE prior to TMT injection. These findings indicate the significant protective effects of ARE against the TMT-induced massive activation of microglia and astrocytes in the hippocampus. Conclusions : We conclude that ARE minimizes the detrimental effects of TMT-induced hippocampal neurotoxicity, both in vitro and in vivo . Our findings may serve as useful guidelines to support ARE administration as a promising pharmacotherapeutic approach to hippocampal degeneration.

• 생명과학회지
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• 제33권5호
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• pp.429-435
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• 2023

역학 연구에 따르면 임신 중 산모의 감염, 산모의 스트레스, 환경적 위험 요인이 태아의 인지 장애와 관련된 뇌 발달 이상 위험을 증가시키고 정신분열증 및 자폐 스펙트럼 장애에 대한 감수성을 증가시키는 것으로 나타났다. 여러 동물 모델은 모체 면역 활성화(MIA)가 태아와 자손의 비정상적인 뇌 발달 및 행동 결함을 유발하기에 충분하다는 것이 입증되었다. 모체 면역활성화 동물 모델에는 흔히 바이러스 모방 Poly I:C 또는 박테리아 유래물질 LPS 등을 임신한 어미에 도입시킴으로서 모체 면역이 활성화되며, 친염증성 사이토카인이 증가하고 자손의 뇌에서 미세아교세포 활성이 관찰되었다. 미세아교세포는 중추신경계에서 중재 역할을 하는 뇌 상주 면역 세포이다. 미세아교세포는 식균 작용, 시냅스 형성 및 분지, 혈관 신생과 같은 다양한 기능을 담당하는 것으로 알려져 있다. 여러 연구에서 미세아교세포가 모체면역활성화 자손에서 활성화되어 있고, 다양한 사이토카인과의 상호작용을 통해 자손 행동에 영향을 미침이 보고되었다. 또한 신경세포와 별아교세포와의 상호작용을 통해 뇌회로에서도 중요한 역할을 담당한다. 그러나 미세아교세포가 뇌 발달 및 행동 결함에 필수적인지에 대해서는 논란이 있으며 정확한 메커니즘은 아직 알려지지 않다. 따라서 뇌 발달 장애의 잠재적 진단 및 치료를 위해서는 모체면역활성화 동물 모델에서 미세아교세포 기능 연구의 필요성이 더욱 요구되고 있다.