• Animal cells and systems
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• 제8권1호
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• pp.57-63
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• 2004

This study provides evidence that expression of EphA8 receptor in NG108-15 cells results in a substantial increase in the number of neurite-bearing cells. However, the EphA8-induced neurite outgrowth does not require either ephrin-A5 stimulation or ectopic expression of $p110{\gamma}$ PI-3 kinase. In contrast, co-expression of a lipid kinase-inactive $p110{\gamma}$ mutant together with EphA8 causes neurite retraction in the presence of ephrin-A5 stimulation. This effect was not observed in the absence of ephrin-A5 stimulation. Significantly, the tyrosine kinase activity of EphA8 is not important for either of these processes. Taken together, our results strongly suggest that $p110{\gamma}$ PI-3 kinase is critically involved in the regulatory process by which ephrin-A5 exerts effects on the EphA8-induced neurite outgrowth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.1-4
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• 2003

In this study, we showed that neurons could be generated from adult canine bone marrow stem cells by culturing with $DMSO/BHA/FeCl_2$. These neurons differentiated from the bone marrow stem cells formed neurites, expressed neuron-specific markers. This differentiation was enhanced by $FeCl_2$. These results suggest that iron can effectively initiate differentiation of adult bone marrow stem cells into neurons.

• 생물정신의학
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• 제10권2호
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• pp.126-132
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• 2003

Objectives:The purpose of this study is to examine the effects of venlafaxine, one of novel antidepressant drugs, on neurite growth in PC12 cells. Methods:PC12 cells were cultured with NGF for eight days. Then different concentrations($0{\mu}M$, $1{\mu}M$, $5{\mu}M$) of venlafaxine were mixed with cultured PC12 cells. After 24 hours and 48 hours of culture, we compared the effects of venlafaxine on the total length of neurites of cultured PC12 cells between no venlafaxine treated group($0{\mu}M$) and venlafaxine treated groups($1{\mu}M$ and $5{\mu}M$). Additionally, we studied the concentration-dependent effect of venlafaxine on differentiation in PC12 cells. Results:Experimental results showed that 1) the mean length of neurites in $1{\mu}M$ and $5{\mu}M$ venlafaxine treated group was more increased than no venlafaxine treated group(p=0.002). 2) the length of neurite in $5{\mu}M$ venlafaxine treated group was more elongated than $1{\mu}M$ venlafaxine treated group(p=0.046). 3) the length of neurite in $6{\mu}M$ venlafaxine treated group was more elongated than all the other concentrations in our experiment. Above $6{\mu}M$, the length of neurite was shortened in inverse proportion to the concentration of venlafaxine. Conclusions:This results suggest that venlafaxine, one of novel antidepressant drugs, promotes the differentiation of neuron. This study is believed to be a first step toward understanding the molecular and cellular mechanisms of antidepressant treatment.

• BMB Reports
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• 제46권5호
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• pp.276-281
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• 2013

In this study, we aimed to compare the morphogenetic and neuronal characteristics between monolayer cells and spheroids. For this purpose, we established spheroid formation by growing SH-SY5Y cells on the hydrophobic surfaces of thermally-collapsed elastin-like polypeptide. After 4 days of culture, the relative proliferation of the cells within spheroids was approximately 92% of the values for monolayer cultures. As measured by quantitative assays for mRNA and protein expressions, the production of synaptophysin and neuronspecific enolase (NSE) as well as the contents of cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins are much higher in spheroids than in monolayer cells. Under the all-trans-retinoic acid (RA)-induced differentiation condition, spheroids extended neurites and further up-regulated the expression of synaptophysin, NSE, CAMs, and ECM proteins. Our data indicate that RA-differentiated SH-SY5Y neurospheroids are functionally matured neuronal architectures.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3071-3075
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• 2012

Human ${\alpha}$-synuclein is the major component of the protein aggregates known as Lewy bodies or Lewy neurites, which define the intracellular lesions of Parkinson's disease. Despite extensive efforts, the physiological function of ${\alpha}$-synuclein has not yet been elucidated in detail. As an approach to defining its function, proteins that interacted with ${\alpha}$-synuclein were screened in phage display assays. The SNARE protein vesicle t-SNARE-interacting protein homologous 1B (VTI1B) was identified as an interacting partner. A selective interaction between ${\alpha}$-synuclein and VTI1B was confirmed by coimmunoprecipitation and GST pull-down assays. VTI1B and ${\alpha}$-synuclein were colocalized in N2a neuronal cells, and overexpression of ${\alpha}$-synuclein changed the subcellular localization of VTI1B to be more dispersed throughout the cytosol. Considering the role played by VTI1B, ${\alpha}$-synuclein is likely to modulate vesicle trafficking by interacting with a SNARE complex.

• International Journal of Oral Biology
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• 제41권4호
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• pp.231-236
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• 2016

Inhibition of Rho-associated coiled coil-containing kinase (ROCK) has been reported to promote differentiation of neuronal cells. Here, we examined the effect of Y-27632, a ROCK inhibitor, on the outgrowth of neurites in PC12 cells. Y-27632 caused a rapid induction of neurite outgrowth in PC12 cells in a time-dependent manner. The neurite outgrowth, triggered by Y-27632, was accompanied by Rac1 activation, and was attenuated by Rac1 inhibitor NSC23766, in a concentration-dependent manner. Y-27632 also induced an increase in the production of reactive oxygen species (ROS). Pretreatment with N-acetylcysteine, an ROS scavenger, inhibited the ROS generation and neurite outgrowth in response to Y-27632. These results indicate that the activation of Rac1 and the generation of ROS contribute to the neurite outgrowth triggered by Y-27632 in PC12 cells.

• BMB Reports
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• 제46권12호
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• pp.617-622
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• 2013

Rac1 plays a key role in neurite outgrowth via reorganization of the actin cytoskeleton. The molecular mechanisms underlying Rac1-mediated actin dynamics in the cytosol and plasma membrane have been intensively studied, but the nuclear function of Rac1 in neurite outgrowth has not yet been addressed. Using subcellular fractionation and immunocytochemistry, we sought to explore the role of nuclear Rac1 in neurite outgrowth. bFGF, a strong agonist for neurite outgrowth in PC12 cells, stimulated the nuclear accumulation of an active form of Rac1. Rac1-PBR (Q) mutant, in which six basic residues in the polybasic region at the C-terminus were replaced by glutamine, didn't accumulate in the nucleus. In comparison with control cells, cells expressing this mutant form of Rac1 displayed a marked defect in extending neurites that was concomitant with reduced expression of MAP2 and MEK-1. These results suggest that Rac1 translocation to the nucleus functionally correlates with bFGF-induced neurite outgrowth.

• Applied Microscopy
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• 제42권4호
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• pp.179-185
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• 2012

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Neuropathological hallmarks of AD are amyloid plaques, dystrophic neurite, and alteration of subcellular organelles. However, the morpho-functional study of this degenerative process and ultimate neuronal death remains poorly elucidated. In this study, immunohistochemical and ultrastructural analyses were performed to clarify the abnormal morphological alterations caused by the progression of AD in APP/PSEN1 transgenic mice, express human amyloid precursor protein, as a model for AD. In transgenic AD mice brain, the accumulation of Amyloid ${\beta}$ plaques and well-developed dystrophic neurites containing anti-LC3 antibody-positive autophagosomes were detected in the hippocampus and cortex regions. We also found severe disruption of mitochondrial cristae using high-voltage electron microscopy and three-dimensional electron tomography (3D tomography). These results provide morpho-functional evidence on the alteration of subcellular organelles in AD and may help in the investigation of the pathogenesis of AD.

• 약학회지
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• 제41권1호
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• pp.99-104
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• 1997

In order to elucidate the cytotoxic effect of oxygen radicals on cultured spinal dorsal root ganglion(DRG) neurons derived from mouse. the neurotoxic effect of oxygen radicals w as examined after cultured DRG neurons were exposed to xanthine oxidase(XO) and hypoxanthine(HX)-oxygen radical generating system. In addition. neuroprotective effect of epidermal growth factor(EGF) against oxidant-induced neurotoxicity was also evaluated in these cultures. The results were, as follows: 1. Lethal concentration 50(LC$_{50}$) was 35mU/ml XO and 0.1mM HX in cultured DRG neurons. 2. Oxygen radicals induced the morphological changes such as the decrease of cell number and loss of neurites in these cultures. 3. EGF increased the cell viability and neurofilament in neurons damaged by oxygen radicals. From above the results, it is suggested that oxygen radicals have a cytotoxic effect on cultured DRG neurons of neonatal mouse and selective neurotrophic factors such as EGF are, effective, in blocking the neurotoxicity induced by oxygen radicals in cultured spinal DRG neurons.

• 한국동물학회지
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• 제34권2호
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• pp.209-216
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• 1991

신경세포의 분화에 미치는 insulin의 영향을 알아보기 위하여 계배의 단뇌 신경아세포를 serum-free defined medium에서 배양하였다. Immunofluorescence실험을 통하여 신경특이단백질인 MAP-2는 신경아세포의 세포체와 신경돌기에 존재하는 것으로 나타났다. 또한, 배양액내에 insulin의 농도를 증가하면 신경아세포의 신경돌기 형성이 증가할 뿐 아니라 MAP-2의 합성도 증가하였다. 따라서, 신경아세포의 형태적분화와 생화학적 분화는 서로 밀접하게 연관되어 일어나는 것으로 추측되며, insulin은 신경특이단백질의 합성을 촉진시킴으로써 신경아세포가 신경돌기를 형성하며 분화되어 가는데 결정적인 역할을 하는 것으로 보인다.