• BMB Reports
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• v.30 no.4
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• pp.285-291
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• 1997

It is becoming increasingly evident that significant changes in gene expression occur during the course of neuronal differentiation. Thus, it should be possible to gain information about the biochemical events by identifying differentially expressed genes in neuronal differentiation The PC12 cell line is a useful model system to investigate the molecular mechanism underlying neuronal differentiation and has been used extensively for the study of the molecular events that underlie the biological actions of nerve growth factor (NGF). In this study, we report an application of the recently described mRNA differential display method to analyze differential gene expression during neuronal differentiation. Using this technique, we have identified several cDNA tags expressed differentially during neuronal differentiation. Interestingly, one of these clones was cytochrome c oxidase subunit I (COX I) gene. The differential expression of COX I gene was confirmed by Northern blot analysis as well as RT-PCR. Southern blot analysis of the genomic DNA of PC12 cells revealed that COX I is a single gene. Induction of the oxidative enzyme might reflect the energy requirement in neuronal differentiation.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.73-76
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• 2006

Neuronal precursor cells may provide for cell replacement or gene delivery vehicles in neurodegenerative disease therapy. One impediment to treating neuronal diseases is finding ways to introduce genes into neurons effectively. It is shown here that fiber-modified adenovirus vector delivered gene to neuronal precursor as well as differentiated neuronal cells more efficiently than first-generation adenoviral vector. Moreover, fiber-modified adenoviral vector transduced precursor cells retained the potential for differentiation into neurons and glia in vitro. These results show the potential of modified adenoviral vector in the improved gene delivery to neurons in direct gene therapy protocols. In addition it holds promise for the use of genetically manipulated stem cells for the therapy of neuronal diseases.

• Molecules and Cells
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• v.37 no.7
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• pp.511-517
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• 2014

MicroRNAs are non-coding short (~23 nucleotides) RNAs that mediate post-transcriptional regulation through sequence-specific gene silencing. The role of miRNAs in neuronal development, synapse formation and synaptic plasticity has been highlighted. However, the role of neuronal activity on miRNA regulation has been less focused. Neuronal activity-dependent regulation of miRNA may finetune gene expression in response to synaptic plasticity and memory formation. Here, we provide an overview of miRNA regulation by neuronal activity including high-throughput screening studies. We also discuss the possible molecular mechanisms of activity-dependent induction and turnover of miRNAs.

• BMB Reports
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• v.56 no.3
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• pp.153-159
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• 2023

Neuronal differentiation is highly coordinated through a cascade of gene expression, mediated via interactions between trans-acting transcription factors and cis-regulatory elements of their target genes. However, the mechanisms of transcriptional regulation that determine neuronal cell-fate are not fully understood. Here, we show that the nuclear transcription factor Y (NF-Y) subunit, NFYA-1, is necessary and sufficient to express the flp-3 neuropeptide gene in the IL1 neurons of C. elegans. flp-3 expression is decreased in dorsal and lateral, but not ventral IL1s of nfya-1 mutants. The expression of another terminally differentiated gene, eat-4 vesicular glutamate transporter, is abolished, whereas the unc-8 DEG/ENaC gene and pan-neuronal genes are expressed normally in IL1s of nfya-1 mutants. nfya-1 is expressed in and acts in IL1s to regulate flp-3 and eat-4 expression. Ectopic expression of NFYA-1 drives the expression of flp-3 gene in other cell-types. Promoter analysis of IL1-expressed genes results in the identification of several cis-regulatory motifs which are necessary for IL1 expression, including a putative CCAAT-box located in the flp-3 promoter that NFYA-1 directly interacts with. NFYA-1 and NFYA-2, together with NFYB-1 and NFYC-1, exhibit partly or fully redundant roles in the regulation of flp-3 or unc-8 expression, respectively. Taken together, our data indicate that the NF-Y complex regulates neuronal subtype-specification via regulating a set of terminal-differentiation genes.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.111-121
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• 2006

Neuroprotective properties of lithium were evaluated by using in vivo NMDA excitotoxicity model. Systemic injection of NMDA to young mice induced neuronal apoptosis mediated by both TNFR-l and Fas ligand, and long-term lithium treatment showed noticeable neuroprotection against NMDA-induced excitotoxicity: NMDA-damaged neurons expressed several apoptosis-related gene products such as TNFR-l, Fas ligand, and caspase-3, and these gene expressions were not found in the brain of mice chronically treated with lithium. Therefore, it is highly likely that the protection offered by chronic lithium treatment occurred at far upstream of caspase activation, since the chronic lithium treatment increased the expression of Bcl-2, an important antiapoptotic gene known to act upstream of caspase cascade. Timm's histochemistry indicated the complete blockade of the NMDA insults by the treatment. There was no indication of axonal regeneration, which follows synaptic degeneration induced by neuronal damage. Furthermore, this study reports for the first time that TNFR-l and Fas ligand are involved in neuroprotective effects of lithium in NMDA-induced neuronal apoptosis.

• The Korean Journal of Pain
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• v.22 no.1
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• pp.1-15
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• 2009

Neuropathic pain is often refractory to intervention because of the complex etiology and an incomplete understanding of the mechanisms behind this type of pain. Glial cells, specifically microglia and astrocytes, are powerful modulators of pain and new targets of drug development for neuropathic pain. Glial activation could be the driving force behind chronic pain, maintaining the noxious signal transmission even after the original injury has healed. Glia express chemokine, purinergic, toll-like, glutaminergic and other receptors that enable them to respond to neural signals, and they can modulate neuronal synaptic function and neuronal excitability. Nerve injury upregulates multiple receptors in spinal microglia and astrocytes. Microglia influence neuronal communication by producing inflammatory products at the synapse, as do astrocytes because they completely encapsulate synapses and are in close contact with neuronal somas through gap junctions. Glia are the main source of inflammatory mediators in the central nervous system. New therapeutic strategies for neuropathic pain are emerging such as targeting the glial cells, novel pharmacologic approaches and gene therapy. Drugs targeting microglia and astrocytes, cytokine production, and neural structures including dorsal root ganglion are now under study, as is gene therapy. Isoform-specific inhibition will minimize the side effects produced by blocking all glia with a general inhibitor. Enhancing the anti-inflammatory cytokines could prove more beneficial than administering proinflammatory cytokine antagonists that block glial activation systemically. Research on therapeutic gene transfer to the central nervous system is underway, although obstacles prevent immediate clinical application.

• BMB Reports
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• v.41 no.2
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• pp.146-152
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• 2008

In the presence of NGF, PC12 cells extend neuronal processes, cease cell division, become electrically excitable, and undergo several biochemical changes that are detectable in developing sympathetic neurons. We investigated the expression pattern of the apoptosis-related genes at each stage of neuronal differentiation using a cDNA microarray containing 320 apoptosis-related rat genes. By comparing the expression patterns through time-series analysis, we identified candidate genes that appear to regulate neuronal differentiation. Among the candidate genes, HO2 was selected by real-time PCR and Western blot analysis. To identify the roles of selected genes in the stages of neuronal differentiation, transfection of HO2 siRNA in PC12 cells was performed. Down-regulation of HO2 expression causes a reduction in neuronal differentiation in PC12 cells. Our results suggest that the HO2 gene could be related to the regulation of neuronal differentiation levels.

• Molecules and Cells
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• v.43 no.10
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• pp.848-855
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• 2020

Cells assemble stress granules (SGs) to protect their RNAs from exposure to harmful chemical reactions induced by environmental stress. These SGs release RNAs, which resume translation once the stress is relieved. During stem cell differentiation, gene expression is altered to allow cells to adopt various functional and morphological features necessary to differentiate. This process induces stress within a cell, and cells that cannot overcome this stress die. Here, we investigated the role of SGs in the progression of stem cell differentiation. SGs aggregated during the neuronal differentiation of human bone marrow-mesenchymal stem cells, and not in cell lines that could not undergo differentiation. SGs were observed between one and three hours post-induction; RNA translation was restrained at the same time. Immediately after disassembly of SGs, the expression of the neuronal marker neurofilament-M (NF-M) gradually increased. Assembled SGs that persisted in cells were exposed to salubrinal, which inhibited the dephosphorylation of eukaryotic translation initiation factor 2 subunit 1 (eIF2α), and in eIF2α/S51D mutant cells. When eIF2α/S51A mutant cells differentiated, SGs were not assembled. In all experiments, the disruption of SGs was accompanied by delayed NF-M expression and the number of neuronally differentiated cells was decreased. Decreased differentiation was accompanied by decreased cell viability, indicating the necessity of SGs for preventing cell death during neuronal differentiation. Collectively, these results demonstrate the essential role of SGs during the neuronal differentiation of stem cells.

• Toxicological Research
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• v.13 no.4
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• pp.417-421
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• 1997

Synaptobrevin is a kind of vesicle associated membrane proteins (VAMPs) which plays a secretary role in the neuronal synapse and was recently known as the biochemical target of botulinum neurotoxin type B. The structural gene of the synaptobrevin was cloned from mouse brain using RT-PCR technique and was seqrtenced. The deduced amino acid sequence showed that the synaptobrevin protein from mouse brain is exactly the same with that of the rat brain in the amino acid level. The synaptobrevin gene was subcloned into pET3a vector and expressed in E. coli. The molecular weight of the recombinant protein was 19 kDa as expected. Moreover, when the recombinant synaptobrevin protein was incubated with the native neurotoxin of Clostridium botulinum type B, it was cleaved by the toxin in a time dependent manner. This implies that the recombinant synaptobrevin protein and the native toxin are reacted in the same way as the native synaptobrevin did in the neuronal cells.

• Korean Journal of Biological Psychiatry
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• v.12 no.1
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• pp.42-61
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• 2005

Objectives:The ginsenoside Rg1 and Rb1, the major components of ginseng saponin, have neurotrophic and neuroprotective effects including promotion of neuronal survival and proliferation, facilitation of learning and memory, and protection from ischemic injury and apoptosis. In this study, to investigate the molecular basis of the effects of ginsenoside on neuron, we analyzed gene expression profiling of SH-SY5Y human neuroblastoma cells treated with ginsenoside Rg1 or Rb1. Methods:SH-SY5Y cells were cultured and treated in triplicate with ginsenoside Rg1 or Rb1($80{\mu}M$, $40{\mu}M$, $20{\mu}M$). The proliferation rates of SH-SY5Y cells were determined by MTT assay and microscopic examination. We used a high density cDNA microarray chip that contained 8K human genes to analyze the gene expression profiles in SH-SY5Y cells. We analyzed using the Significance Analysis of Microarray(SAM) method for identifying genes on a microarray with statistically significant changes in expression. Results:Treatment of SH-SY5Y cells with $80{\mu}M$ ginsenoside Rg1 or Rb1 for 36h showed maximal proliferation compared with other concentrations or control. The results of the microarray experiment yielded 96 genes were upregulated(${\geq}$3 fold) in Rg1 treated cells and 40 genes were up-regulated(${\geq}$2 fold) in Rb1 treated cells. Treatment with ginsenoside Rg1 for 36h induced the expression of some genes associated with protein biosynthesis, regulation of transcription or translation, cell proliferation and growth, neurogenesis and differentiation, regulation of cell cycle, energy transport and others. Genes associated with neurogenesis and neuronal differentiation such as SCG10 and MLP increased in ginsenoside Rg1 treated cells, but such changes did not occur in Rb1-group. Conclusion:Our data provide novel insights into the gene mechanisms involved in possible role for ginsenoside Rg1 or Rb1 in mediating neuronal proliferation or cell viability, which can elicit distinct patterns of gene expression in neuronal cell line. Ginsenoside Rg1 have more broad and strong effects than ginsenoside Rb1 in gene expression and related cellular physiology. In addition, we suggest that SCG10 gene, which is known to be expressed in neuronal differentiation during development and neuronal regeneration during adulthood, may have a role in enhancement of activity dependent synaptic plasticity or cytoskeletal regulation following treatment of ginsenoside Rg1. Further, ginsenoside Rg1 may have a possible role in regeneration of injured neuron, promotion of memory, and prevention from aging or neuronal degeneration.