• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.102-102
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• 2003

Embryonic stem (ES) cells proliferate extensively in the undifferentiated state and have the potential to differentiate into a variety of cell types in response to various environmental cues. The generation of functional dopaminergic neurons from ES cells is promising for cell replacement therapy to treat Parkinson's disease. We compared the in vitro differentiation potential of pluripotent human embryonic stem (hES, MB03) cells induced with basic fibroblast growth factor (bFGF) or retinoic acid (RA). Both types of treatment 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 brain derived neurotrophic factor (BDNF) or transforming growth factor (TGF)- $\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression, compared to control (P<0.05). In contrast, no effect was observed on the rate of mature or glutamic acid decarboxylase-positive neurons. Immunostaining and HPLC analyses revealed the higher levels of TH (20.3%) and dopamine in bFGF and TGF-$\alpha$ treated hES cells than in RA or BDNF treated hES cells. The results indicate that TGF-$\alpha$ may be successfully used in the bFGF induction protocol to yield higher numbers of functional dopaminergic neurons from hES cells.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.4
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• pp.539-546
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• 2020

Objective: The Jeju native pig (JNP) found on the Jeju Island of Korea is a unique black pig known for high-quality meat. To investigate the genetic uniqueness of JNP, we analyzed the selection signature of the JNP in comparison to commercial pigs such as Berkshire and Yorkshire pigs. Methods: We surveyed the genetic diversity to identify the genetic stability of the JNP, using the linkage disequilibrium method. A selective sweep of the JNP was performed to identify the selection signatures. To do so, the population differentiation measure, Weir-Cockerham's F_st was utilized. This statistic directly measures the population differentiation at the variant level. Additionally, we investigated the gene ontologies (GOs) and genetic features. Results: Compared to the Berkshire and Yorkshire pigs, the JNP had lower genetic diversity in terms of linkage disequilibrium decays. We summarized the selection signatures of the JNP as GO. In the JNP and Berkshire pigs, the most enriched GO terms were epithelium development and neuron-related. Considering the JNP and Yorkshire pigs, cellular response to oxygen-containing compound and generation of neurons were the most enriched GO. Conclusion: The selection signatures of the JNP were identified through the population differentiation statistic. The genes with possible selection signatures are expected to play a role in JNP's unique pork quality.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1100-1105
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• 2006

Purpose : Because NELL2 expression is strictly restricted only in neurons in developing and post-differentiated neural tissues, it is thought to be involved in the neuronal differentiation during development and in the maintenance of neuronal physiology in the post-differentiated neurons. In this study, we examined whether NELL2 is involved in the regulation of cell cycle and apoptosis in the hippocampal neuroprogenitor HiB5 cells. Methods : Effects of NELL2 on the cultured HiB5 cell numbers, DNA fragmentation, and proteins involved in the regulation of the cell cycle were measured. Results : NELL2 induced a decrease in cell numbers and an increase in G1 phase arrest. Moreover, transfection of NELL2 resulted in an increase of DNA fragmentation that shows an evidence of apoptosis. Contents of proteins involved in the regulation of cell cycle were also changed by transfection of NELL2 expression vectors. Conclusion : This study suggests that NELL2 plays an important role in the regulation of cell cycle and apoptosis of neurons.

• Molecules and Cells
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• v.27 no.5
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• pp.571-575
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• 2009

The amphetamine derivative 3, 4-methylenedioxymethamphetamine (MDMA) has become a popular recreational drug, and has also been shown to cause serotonergic neurotoxicity. This report shows that MDMA impairs brain development in a whole mouse embryo culture. The results of quantitative real-time PCR analysis showed that autophagy-related protein 5 (Atg5) expression is elevated in mouse embryo and neuroblastoma cells after MDMA treatment. This elevated Atg5 expression interferes with the neuronal differentiation of neuroblastoma cells such as SH-SY5Y and PC12 cells. Thus, our results suggest that the use of MDMA during pregnancy may impair neuronal development via an induction of Atg5 expression.

• Molecules and Cells
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• v.27 no.4
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• pp.397-401
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• 2009

Olig2 transcription factor is widely expressed throughout the central nervous system; therefore, it is considered to have multiple functions in the developing, mature and injured brain. In this mini-review, we focus on Olig2 in the forebrain (telencephalon and diencephalon) and discuss the functional significance of Olig2 and the differentiation properties of Olig2-expressing progenitors in the development and injured states. Short- and long-term lineage analysis in the developing forebrain elucidated that not all late Olig2+ cells are direct cohorts of early cells and that Olig2 lineage cells differentiate into neurons or glial cells in a region- and stage-dependent manner. Olig2-deficient mice revealed large elimination of oligodendrocyte precursor cells and a decreased number of astrocyte progenitors in the dorsal cortex, whereas no reduction in the number of GABAergic neurons. In addition to Olig2 function in the developing cortex, Olig2 is also reported to be important for glial scar formation after injury. Thus, Olig2 can be essential for glial differentiation during development and after injury.

• Journal of Korean Neurosurgical Society
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• v.44 no.6
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• pp.375-381
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• 2008

Objective : The effects on neural proliferation and differentiation of neural stem cells (NSC) of basic fibroblast growth factor-2 (bFGF). insulin growth factor-I (IGF-I). brain-derived neurotrophic factor (BDNF). and nerve growth factor (NGF) were assessed. Also, following combinations of various factors were investigated : bFGF+IGF-I, bFGF+BDNF, bFGF+NGF, IGF-I+BDNF, IGF-I+NGF, and BDNF+NGF. Methods : Isolated NSC of Fisher 344 rats were cultured with individual growth factors, combinations of factors, and no growth factor (control) for 14 days. A proportion of neurons was analyzed using $\beta$-tubulin III and NeuN as neural markers. Results : Neural differentiations in the presence of individual growth factors for $\beta$-tubulin III-positive cells were : BDNF, 35.3%; IGF-I, 30.9%; bFGF, 18.1%; and NGF, 15.1%, and for NeuN-positive cells was : BDNF, 34.3%; bFGF, 32.2%; IGF-I, 26.6%; and NGF, 24.9%. However, neural differentiations in the absence of growth factor was only 2.6% for $\beta$-tubulin III and 3.1% for NeuN. For $\beta$-tubulin III-positive cells, neural differentiations were evident for the growth factor combinations as follows : bFGF+IGF-I, 73.1 %; bFGF+NGF, 65.4%; bFGF+BDNF, 58.7%; BDNF+IGF-I, 52.2%; NGF+IGF-I, 40.6%; and BDNF+NGF, 40.0%. For NeuN-positive cells : bFGF+IGF-I, 81.9%; bFGF+NGF, 63.5%; bFGF+BDNF, 62.8%; NGF+IGF-I, 62.3%; BDNF+NGF, 56.3%; and BDNF+IGF-I, 46.0%. Significant differences in neural differentiation were evident for single growth factor and combination of growth factors respectively (p<0.05). Conclusion : Combinations of growth factors have an additive effect on neural differentiation. The most prominent neural differentiation results from growth factor combinations involving bFGF and IGF-I. These findings suggest that the combination of a mitogenic action of bFGF and post-mitotic differentiation action of IGF-I synergistically affects neural proliferation and NSC differentiation.

• Journal of Life Science
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• v.26 no.1
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• pp.8-16
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• 2016

Reactive oxygen species (ROS), at appropriate concentrations, mediate various normal cellular functions, including defense against pathogens, signal transduction, cellular growth, and gene expression. A recent study demonstrated that ROS and ROS-generating NADPH oxidase (Nox) are important in self-renewal and neuronal differentiation of subventricular zone (SVZ) neural stem cells in adult mouse brains. In this study, we found that endogenous ROS were detected in SVZ neural stem cells cultured from postnatal mouse brains. Nox4 was predominantly expressed in cultured cells, while the levels of the Nox1 and Nox2 transcripts were very low. In addition, the Nox4 gene was highly upregulated (by up to 10-fold) during neuronal differentiation. Immunocytochemical analysis detected the Nox4 protein mainly in neurons positive for the neuronal specific tubulin Tuj1. After differentiation, endogenous ROS were detected exclusively in neuron-like cells with processes. In addition, perturbation of the cellular redox state with N-acetyl cysteine, a ROS scavenger, during neuronal differentiation greatly inhibited neurogenesis. Lastly, knockdown of Nox4 using short hairpin RNA decreased neurogenesis. These findings suggest that Nox4 may be a major ROS-generating enzyme in postnatal SVZ neural stem cells, and Nox4-mediated ROS generation may be important in their neuronal differentiation.

• BMB Reports
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• v.43 no.2
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• pp.122-126
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• 2010

Homozygous staggerer ($RORa^{sg/sg}$) mice showed a severe ataxia caused by cerebellum degeneration. Decreased and dysfunctional Rora is a main cause of this neurologic phenotype. The phenotype of staggerer mice has been well known in cerebellum. However, there has been rarely reported about cerebrum even though of staggerer is expressed in merely cerebellum but hippocampus, thalamus, cortex, and olfactory bulb. The expressions of Ki67, doublecortin (DCX), and NeuN, which are cell proliferation, neuronal differentiation and mature neuron markers, respectively, were measured with immunohistechemistry in dentate gyrus in staggerer mice in order to uncover whether staggerer can affect the change in dentate gyrus. The immunoreactivities of DCX and NeuN were significantly reduced in the dentate gyrus of staggerer mice than normal control, while Ki67 were rarely unchanged in staggerer mice. These results suggest that staggerer mutation has an influence on the neuronal differentiation and development not only in cerebellum but also in dentate gyrus.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.48-55
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• 2010

Neural progenitor cells (NPCs) differentiate into astrocytes, neurons and oligodendrocytes, which is controlled by various factors in brain. Recent evidences suggest that small molecules modulating the proliferation and differentiation of NPCs may have therapeutic value as well as the potential use as chemical probes. Phylligenin is a lignan with anti-inflammatory activity that is isolated from the fruits of Forsythia koreana. We investigated effects of phylligenin on proliferation and differentiation of NPCs. Treatment of phylligenin decreased the number of proliferating NPCs in culture without effects on the differentiation and survival of neural cells such as neurons and astrocytes. To examine the mechanism of the decreased NPCs number, we performed cell cycle analysis. Proliferation of NPCs was decreased via G1-S transition block by phylligenin treatment, and it was mediated by the increase of p21 level. However, phylligenin did not induce apoptosis of NPCs as determined by TUNEL assay and PARP cleavage. We also found that viability of glioma cell lines such as C6 and U87MG glioma cells, but not that of primary neuron and astrocyte, was inhibited by phylligenin. These results suggest that phylligenin selectively inhibits proliferation of rapidly growing cells such as neural stem cells and glioma cells. Given that the possible role of brain tumor stem cells in the pathology of brain cancers, the inhibitory effects of phylligenin might be useful in the development of new therapeutic agents against brain cancers.

• Development and Reproduction
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• v.11 no.3
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• pp.235-243
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• 2007

Human umbilical cord blood(HUCB) contains a rich source of hematopoietic stem cells, mesenchymal stem cells and endothelial cell precursors. Mesenchymal stem cells(MSCs) in HUCB are multipotent stem cells, differ from hematopoietic stem cells and can be differentiated into neural cells. We studied on transdifferentiation-promoting conditions in neural cells and cholinergic neuron induction of HUCB-derived MSCs. Neural differentiation was induced by addingdimethyl sulphoxide(DMSO) and butylated hydroxyanisole(BHA) in Dulbeco's Modified Essential Medium(DMEM) and fetal bovine serum(FBS). Differentiation of MSCs to cholinergic neurons was induced by combined treatment with basic fibroblast growth factor(bFGF), retinoic acid(RA) and sonic hedgehog(Shh). MSCs treated with DMSO and BHA rapidly assumed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including $\beta$-tubulin III, GFAP and MBP, was markedly elevated during this acute differentiation. The differentiation rate was about $32.3{\pm}2.9%$ for $\beta$-tubulin III-positive cells, $11.0{\pm}0.9%$ for GFAP, and $9.4{\pm}1.0%$ for Gal-C. HUCB-MSCs treated combinatorially with bFGF, RA and Shh were differentiated into cholinergic neurons. After cholinergic neuronal differentiation, the $\beta$-tubulin III-positive cell population of total cells was $31.3{\pm}3.2%$ and of differentiated neuronal population, $70.0{\pm}7.8%$ was ChAT-positive showing 3 folds higher in cholinergic population than neural induction. Conclusively, HUCB-derived MSCs can be differentiated into neural and cholinergic neurons and these findings suggest that HUCB are alternative cell source of treatment for neurodegenerative diseases such as Alzheimer's disease.