• Molecules and Cells
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• v.40 no.4
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• pp.314-314
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• 2017

• Molecules and Cells
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• v.22 no.1
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• pp.8-12
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• 2006

Neuron-derived orphan receptor (NOR-1) is a member of the thyroid/steroid receptor superfamily that was originally identified in forebrain neuronal cells undergoing apoptosis. In addition to apoptotic stimuli, activation of several signal transduction pathways including direct neuronal depolarization regulates the expression of NOR-1. In this study we tested whether the expression of NOR-1 is changed following transient ischemic injury in the adult rat brain. NOR-1 mRNA increased rapidly in the dentate gyrus of the hippocampal formation and piriform cortex 3 h after transient global ischemia and returned to basal level at 6 h. On the other hand, oxygen-glucose deprivation of cultured cerebral cortical neurons did not alter the expression of NOR-1. These results suggest that expression of NOR-1 is differentially regulated in different brain regions in response to globally applied brain ischemia, but that hypoxia is not sufficient to induce its expression.

• 한국전자현미경학회:학술대회논문집
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• 2005.11a
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• pp.144-146
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• 2005

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.138-139
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• 2005

• International Journal of Stem Cells
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• v.16 no.4
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• pp.415-424
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• 2023

Therapeutic efficacy of mesenchymal stem cells (MSCs) is determined by biodistribution and engraftment in vivo. Compared to intravenous infusion, biodistribution of locally transplanted MSCs are partially understood. Here, we performed a pharmacokinetics (PK) study of MSCs after local transplantation. We grafted human MSCs into the brains of immune-compromised nude mice. Then we extracted genomic DNA from brains, lungs, and livers after transplantation over a month. Using quantitative polymerase chain reaction with human Alu-specific primers, we analyzed biodistribution of the transplanted cells. To evaluate the role of residual immune response in the brain, MSCs expressing a cytosine deaminase (MSCs/CD) were used to ablate resident immune cells at the injection site. The majority of the Alu signals mostly remained at the injection site and decreased over a week, finally becoming undetectable after one month. Negligible signals were transiently detected in the lung and liver during the first week. Suppression of Iba1-positive microglia in the vicinity of the injection site using MSCs/CD prolonged the presence of the Alu signals. After local transplantation in xenograft animal models, human MSCs remain predominantly near the injection site for limited time without disseminating to other organs. Transplantation of human MSCs can locally elicit an immune response in immune compromised animals, and suppressing resident immune cells can prolong the presence of transplanted cells. Our study provides valuable insights into the in vivo fate of locally transplanted stem cells and a local delivery is effective to achieve desired dosages for neurological diseases.

• Molecules and Cells
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• v.45 no.11
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• pp.846-854
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• 2022

Neurons make long-distance connections via their axons, and the accuracy and stability of these connections are crucial for brain function. Research using various animal models showed that the molecular and cellular mechanisms underlying the assembly and maintenance of neuronal circuitry are highly conserved in vertebrates. Therefore, to gain a deeper understanding of brain development and maintenance, an efficient vertebrate model is required, where the axons of a defined neuronal cell type can be genetically manipulated and selectively visualized in vivo. Placental mammals pose an experimental challenge, as time-consuming breeding of genetically modified animals is required due to their in utero development. Xenopus laevis, the most commonly used amphibian model, offers comparative advantages, since their embryos ex utero during which embryological manipulations can be performed. However, the tetraploidy of the X. laevis genome makes them not ideal for genetic studies. Here, we use Xenopus tropicalis, a diploid amphibian species, to visualize axonal pathfinding and degeneration of a single central nervous system neuronal cell type, the retinal ganglion cell (RGC). First, we show that RGC axons follow the developmental trajectory previously described in X. laevis with a slightly different timeline. Second, we demonstrate that co-electroporation of DNA and/or oligonucleotides enables the visualization of gene function-altered RGC axons in an intact brain. Finally, using this method, we show that the axon-autonomous, Sarm1-dependent axon destruction program operates in X. tropicalis. Taken together, the present study demonstrates that the visual system of X. tropicalis is a highly efficient model to identify new molecular mechanisms underlying axon guidance and survival.

• Biomedical Science Letters
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• v.11 no.3
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• pp.311-318
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• 2005

Grp78, discovered as one of the putative target genes of Hoxc8, is a highly conserved stress protein and functions as a molecular chaperone in the endoplasmic reticulum (ER). In order to see the stage-specific expression pattern of Grp78 during development, mouse embryos from day 7.5 to 17.5 p.c. were isolated, and RT-PCR as well as in situ hybridization was performed. When RT-PCR was performed using Grp78 specific primers, periodic expression pattern was detected. And also a region-specific expression pattern was detected with a strong expression in the trunk part of day 11.5 p.c. embryo, like that of Hoxc8. When in situ hybridization was performed, Grp78 was revealed to be expressed in the endoderm, somite, neuroepithelium cells of neural tube in early embryos. In the case of late embryos, Grp78 expression was detected in the liver, segmental bronchus within cranial lobe of lung, ossification center within the cartilage primordium of rib and vertebra, submandibular gland, as well as metanephros. These expression patterns are very much similar to those of Hoxc8. Since Hoxc8 has been reported to regulate apoptosis during organogenesis, it might be possible that the apoptotic function could have been conveyed through the expression of Grp78, implying that the Grp78 is one of the Hoxc8 downstream target genes.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.575-578
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• 2023

Anterior cerebral arteries are paired and supply the major portion of the medial surface of the brain. They are branches of the intracranial part of the internal carotid artery and form the anterior portion of the circle of Willis (CW) which is situated in the interpeduncular fossa. During routine dissection in the department of anatomy, All India Institute of Medical Sciences, Bibinagar, Hyderabad, a rare variation had been observed in the CW, azygos anterior cerebral artery associated with hypoplastic A1 fragment of the right anterior cerebral artery in a 63-year-old female cadaver. It is important to identify and study this kind of rare variation for surgeons, anatomists, and radiologists during dissection, surgical, radiological, and diagnostic interventions.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.118-119
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• 2005

• 한국전자현미경학회:학술대회논문집
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• 2004.05a
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• pp.55-56
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• 2004