• BMB Reports
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• 제35권1호
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• pp.87-93
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• 2002

Neural cell survival is an essential concern in the aging brain and many diseases of the central nervous system. Neural transplantation of the stem cells are already applied to clinical trials for many degenerative neurological diseases, including Huntington's disease, Parkinson's disease, and strokes. A critical problem of the neural transplantation is how to reduce their apoptosis and improve cell survival. Neurotrophic factors generally contribute as extrinsic cues to promote cell survival of specific neurons in the developing mammalian brains, but the survival factor for neural stem cell is poorly defined. To understand the mechanism controlling stem cell death and improve cell survival of the transplanted stem cells, we investigated the effect of plausible neurotrophic factors on stem cell survival. The neural stem cell, HiB5, when treated with PDGF prior to transplantation, survived better than cells without PDGF. The resulting survival rate was two fold for four weeks and up to three fold for twelve weeks. When transplanted into dorsal hippocampus, they migrated along hippocampal alveus and integrated into pyramidal cell layers and dentate granule cell layers in an inside out sequence, which is perhaps the endogenous pathway that is similar to that in embryonic neurogenesis. Promotion of the long term-survival and differentiation of the transplanted neural precursors by PDGF may facilitate regeneration in the aging adult brain and probably in the injury sites of the brain.

• 한국발생생물학회지:발생과생식
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• 제13권3호
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• pp.173-181
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• 2009

One of the most extensively studied populations of multipotent adult stem cells are mesenchymal stem cells (MSCs). MSCs derived from the human umbilical cord vein (HUC-MSCs) are morphologically and immunophenotypically similar to MSCs isolated from bone marrow. HUC-MSCs are multipotent stem cells, differ from hematopoietic stem cells and can be differentiated into neural cells. Since neural tissue has limited intrinsic capacity of repair after injury, the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesenchymal-like stem cells from the human umbilical cord vein, and studied transdifferentiation-promoting conditions in neural cells. Dopaminergic neuronal differentiation of HUC-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulfoxide (DMSO) and butylated hydroxyanisole (BHA) in N2 medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. HUC-MSCs treated with bFGF, SHH and FGF8 were differentiated into dopaminergic neurons that were immunopositive for tyrosine hydroxylase (TH) antibody. HUC-MSCs treated with DMSO and BHA rapidly showed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including NeuroD1, $\beta$-tubulin III, GFAP and nestin was markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after neural differentiation, we confirmed the differentiation of dopaminergic neurons by TH/$\beta$-tubulin III positive cells. In conclusion, HUC-MSCs can be differentiated into dopaminergic neurons and these findings suggest that HUC-MSCs are alternative cell source of therapeutic treatment for neurodegenerative diseases.

• 생명과학회지
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• 제12권3호
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• pp.306-316
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• 2002

흰쥐의 좌골신경을 절단한 후 혈관내에서 배양한 신경줄기세포를 이식하여 말초신경에서도 수초의 재생이 일어나는지를 형태 학적으로 규명하고 배양한 신경줄기 세포들로부터 분화한 Schwann cell들이 회복할 수 있는지를 조사하여 다음과 같은 결론을 얻었다. 이식한 20일 후 동맥내 배양한 신경줄기세포는 Schwann cell로 분화하여 신경섬유의 재생이 일어나기 시작하였다. Schwann cell은 증식 후 재수초화를 형성하기 위하여 다른 Schwann cell들로부터 여러 가지를 자극을 받고 있었으며 NGF 소견으로 볼 때 신경외막으로부터 기존의 Schwann cell로부터 신경줄기세포의 분화가 유도되었으며 PCNA 반응으로 볼 때도 기존의 신경섬유의 Schwann cell주위에서부터 증식이 일어났다. 미세구조적으로는 Schwann cell의 재수초화, 축삭내 사립체와 미세소관의 수의 증가를 관찰할 수 있었다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.84-84
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• 2002

This study was to investigate generation of the specific neuronal cell in vitro from the neural progenitors derived from human embryonic stem (hES, MB03) cells. For the neural progenitor cell formation, we produced embryoid bodies (EB: for 5 days, without mitogen) from hES cells and then neurospheres (for 7-10 days, 20 ng/㎖ of bFGF added N2 medium) from EB. And then for the differentiation into neuronal cells, neural progenitor cells were cultured in N2 medium (without bFGF) supplemented with brain derived neurotrophic factor (BDNF, 5 ng/㎖) or platelet derived growth factor-bb (pDGF-bb, 20ng/㎖) for 2 weeks. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.23-30
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• 2013

Neural stem cells (NSCs) have the ability to proliferate and differentiate into various types of cells that compose the nervous system. To study functions of genes in stem cell biology, genes or siRNAs need to be transfected. However, it is difficult to transfect ectopic genes into NSCs. Thus to identify the suitable method to achieve high transfection efficiency, we compared lipid transfection, electroporation, nucleofection and retroviral transduction. Among the methods that we tested, we found that nucleofection and retroviral transduction showed significantly increased transfection efficiency. In addition, with retroviral transduction of Ngn2 that is known to induce neurogenesis in various types of cells, we observed facilitated final cell division in rat NSCs. These data suggest that nucleofection and retroviral transduction provide high efficiency of gene delivery system to study functions of genes in rat NSCs.

• Clinical and Experimental Otorhinolaryngology
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• 제11권4호
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• pp.224-232
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• 2018

Objectives. Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. Methods. The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. Results. There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. Conclusion. Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.

• Journal of Genetic Medicine
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• 제12권1호
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• pp.31-37
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• 2015

Purpose: We investigated the neurogenic potentials of amniotic fluid-derived stem cells (AFSCs) according to the expression levels of stem cell markers and ingredients in the neural induction media. Materials and Methods: Four samples of AFSCs with different levels of Oct-4 and c-kit expression were differentiated neurally, using three kinds of induction media containing retinoic acid (RA) and/or a mixture of 3-isobutyl-1-methylxanthine/indomethacin/insulin (neuromix), and examined by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) for their expression of neurospecific markers. Results: The cells in neuromix-containing media displayed small nuclei and long processes that were characteristic of neural cells. RT-PCR analysis revealed that the number of neural markers showing upregulation was greater in cells cultured in the neuromix-containing media than in those cultured in RA-only medium. Neurospecific gene expression was also higher in Oct-4 and c-kit double-positive cells than in c-kit-low or -negative cells. Conclusion: The stem cell marker c-kit (rather than Oct-4) and the ingredient neuromix (rather than RA) exert greater effects on neurogenesis of AFSCs.

• 대한의생명과학회지
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• 제13권4호
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• pp.273-278
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• 2007

Stem cells have been the subject of increasing scientific interest because of their utility in numerous biomedical applications. Stem cells are capable of renewing themselves; that is, they can be continuously cultured in an undifferentiated state, giving rise to more specialized cells of the human body. Therefore, stem cells are an important new tools for developing unique, in vitro model systems to test drugs and chemicals and a potential to predict or anticipate toxicity in humans. In the present study, in vitro cultured F3 immortalized human neural stem cell line and in vivo adult Sprague Dawley rats was used to evaluate the cytotoxicity of anticancer drug paclitaxel. In vitro apoptotic activity of paclitaxel was evaluated in F3 cell line by a MTT assay and DAPI test. The cell death was induced with the treatment of 20 nM paclitaxel and chromatin degradation was detected by DAPI staining, which was analyzed by fluorescent microscope. In vivo studies, we also observed nestin immunoreactivity on subventricular zone, which is stem cell rich region in the adult brain of the SD rat. Immunofluorescent staining result shows that pixel intensities of nestin were decreased in a dose dependent manner. These results suggest that paclitaxel is able to induce cytotoxic activity both in F3 neural stem cell line and neural stem cell in SD rat brain.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.19-19
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• 2002

This study was to examine whether the in vitro differentiated neural cells derived from human embryonic stem (hES, MB03) cells can be survived and expressed tyrosin hydroxylase(TH) in grafted normal or PD rat brain. To differentiate in vitro into neural cells, embryoid bodies (EB: for 5 days, without mitogen) were formed from hES cells, neural progenitor cells(neurosphere, for 7-10 days, 20 ng/㎖ of bFGF added N2 medium) were produced from EB, and then finally neurospheres were differentiated into mature neuron cells in N2 medium(without bFGF) for 2 weeks. In normal rat brain, neural progenitor cells or mature neuron cells (1×10/sup 7/ cells/㎖) were grafted to the striatum of normal rats. After 2 weeks, when the survival of grafted hES cells was examined by immunohistochemical analysis, the neural progenitor cell group indicated higher BrdU, NeuN＋, MAP2＋ and GFAP＋ than mature neuron cell group in grafted sites of normal rats. This result demonstrated that the in vivo differentiation of grafted hES cells be increased simultaneously in both of neuronal and glial cell type. Also, neural progenitor cell grafted normal rats expressed more TH pattern than mature neuron cells. Based on this data, as a preliminary test, when the neural progenitor cells were grafted into the striatum of 6-hydroxydopamine lesioned PD rats, we confirmed the cell survival (by double staining of Nissl and NeuN) and TH expression. This result suggested that in vitro differentiated neural progenitor cells derived from hES cells are more usable than mature neuron cells for the neural cell grafting in animal model and those grafted cells were survived and expressed TH in normal or PD rat brain.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.227-237
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• 2009

최근 골수와 혈액으로 유래된 중간엽 줄기세포와 비슷한 능력을 가지는 것으로 알려진 지방 유래 중간엽줄기세포가 새로운 세포 치료제로 떠오르고 있다. 하지만 줄기세포를 이용하여 치료하려는 질병은 나이가 들어감에 따라 발병하는 퇴행성 질환들이 대부분인데, 노화가 진행됨에 따라 줄기세포의 능력이 차이가 있다고 알려져 있다. 이에 본 연구에서는 노화가 일어남에 따라 발생되는 신경성 질환을 자가 유래 지방 중간엽 줄기세포를 이용하여 치료함에 있어서 노화가 진행됨에 따라 얻어진 지방줄기세포가 세포학적으로 변화는 없는지에 대해 줄기세포 성장능, 생존율과 신경세포로의 분화유도 능력을 비교하였다. 30대, 40대, 50대에서 사람 지방 유래 줄기세포를 분리 배양하여 연령별 계대에 따른 세포수와 생존율을 측정하고, 줄기세포 성장능력을 비교 분석하였고, 지방 줄기세포를 신경세포 배양 조건 하에서 10일 동안 배양하여 신경 분화능력을 연령별로 비교하였다. 실험결과, 세포수와 생존율, 세포 모양이 연령과 계대별에 의해 차이가 없다는 것을 확인하였다. 신경 분화 후 면역형광염색법을 통해 분석한 결과, 연령에 따른 신경 분화능력의 차이가 관찰되지 않았다. 분자 유전적학으로 신경세포 마커의 발현을 mRNA 수준에서 분석한 결과, 연령별 간의 차이가 몇 개의 유전자 발현을 제외하고는 차이가 발견되지 못했다. 하지만 계대가 진행될수록 50대군의 줄기세포에서 MAP2와 Sox2의 mRNA 발현이 30대군의 줄기세포에 비해 상대적으로 낮게 발현됨이 확인되었다. 결론적으로 자가 지방 중간엽 줄기세포의 신경세포 분화능력이 연령에 상관없이 차이가 없음이 관찰되었으며, 이는 나이 든 사람으로부터 얻어진 지방 줄기세포도 젊은 사람에서 얻어진 세포와 마찬가지 능력으로 자가 세포 치료제로 사용될 수 있다는 점을 말해주고 있다.