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In Vitro Expansion of Homogeneous Neural Precursor Cells Derived from Human Embryonic Stem Cells
Deuk-Chae Na,Sehee Kim,Won-Ik Choi,Hyun-Jin Hwang,Inho Han,Jae-hwan Kim,Keun-Hong Park,Hyung-Min Chung,Seong-Jun Choi 한국동물생명공학회(구 한국동물번식학회) 2007 Reproductive & developmental biology Vol.31 No.4
Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and have the capacity to differentiate into various types of cells in the body. Hence, these cells may potentially be an indefinite source of cells for cell therapy in various degenerative diseases including neuronal disorders. For clinical applications of human ES cells, directed differentiation of these cells would be necessary. The objective of this study is to develop the culture condition for the expansion of neural precursor cells derived from human ES cells. Human ES cells were able to differentiate into neural precursor cells upon a stepwise culture condition. Neural precursor cells were propagated up to 5000-fold in cell numbers over 12-week period of culture and evaluated for their characteristics. Expressions of sox1 and pax6 transcripts were dramatically up-regulated along the differentiation stages by RT-PCR analysis. In contrast, expressions of oct4 and nanog transcripts were completely disappeared in neural precursor cells. Expressions of nestin, pax6 and sox1 were also confirmed in neural precursor cells by immunocytochemical analysis. Upon differentiation, the expanded neural precursor cells differentiated into neurons, astrocytes, and oligodendrocytes. In immunocytochemical analysis, expressions of type III β-tubulin and MAP2ab were observed. Presence of astrocytes and oligodendrocytes were also confirmed by expressions of GFAP and O4, respectively. Results of this study demonstrate the feasibility of long-term expansion of human ES cell-derived neural precursor cells in vitro, which can be a potential source of the cells for the treatment of neurodegenerative disorders.
In Vitro Expansion of Homogeneous Neural Precursor Cells Derived from Human Embryonic Stem Cells
Na, Deuk-Chae,Kim, Se-Hee,Choi, Won-Ik,Hwang, Hyun-Jin,Han, In-Bo,Kim, Jae-Hwan,Park, Keun-Hong,Chung, Hyung-Min,Choi, Seong-Jun The Korean Society of Animal Reproduction 2007 Reproductive & developmental biology Vol.31 No.4
Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and have the capacity to differentiate into various types of cells in the body. Hence, these cells may potentially be an indefinite source of cells for cell therapy in various degenerative diseases including neuronal disorders. For clinical applications of human ES cells, directed differentiation of these cells would be necessary. The objective of this study is to develop the culture condition for the expansion of neural precursor cells derived from human ES cells. Human ES cells were able to differentiate into neural precursor cells upon a stepwise culture condition. Neural precursor cells were propagated up to 5000-fold in cell numbers over 12-week period of culture and evaluated for their characteristics. Expressions of sox1 and pax6 transcripts were dramatically up-regulated along the differentiation stages by RT-PCR analysis. In contrast, expressions of oct4 and nanog transcripts were completely disappeared in neural precursor cells. Expressions of nestin, pax6 and sox1 were also confirmed in neural precursor cells by immunocytochemical analysis. Upon differentiation, the expanded neural precursor cells differentiated into neurons, astrocytes, and oligodendrocytes. In immunocytochemical analysis, expressions of type III ${\beta}$-tubulin and MAP2ab were observed Presence of astrocytes and oligodendrocytes were also confirmed by expressions of GFAP and O4, respectively. Results of this study demonstrate the feasibility of long-term expansion of human ES cell-derived neural precursor cells in vitro, which can be a potential source of the cells for the treatment of neurodegenerative disorders.
Seok, Jae Yeon,Na, Deuk Chae,Woo, Hyun Goo,Roncalli, Massimo,Kwon, So Mee,Yoo, Jeong Eun,Ahn, Ei Yong,Kim, Gwang Il,Choi, Jin‐,Sub,Kim, Young Bae,Park, Young Nyun Wiley Subscription Services, Inc., A Wiley Company 2012 Hepatology Vol.55 No.6
<P><B>Abstract</B></P><P>Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the major primary liver cancers in adults. The phenotypic overlap between HCC and CC has been shown to comprise a continuous liver cancer spectrum. As a proof of this concept, a recent study demonstrated a genomic subtype of HCC that expressed CC‐like gene expression traits, such as CC‐like HCC, which revealed the common genomic trait of stem‐cell–like properties and aggressive clinical outcomes. Scirrhous HCC (S‐HCC), a rare variant of HCC, is characterized by abundant fibrous stroma and has been known to express several liver stem/progenitor cell markers. This suggests that S‐HCC may harbor common intermediate traits between HCC and CC, including stem‐cell traits, which are similar to those of CC‐like HCC. However, the molecular and pathological characteristics of S‐HCC have not been fully evaluated. By performing gene‐expression profiling and immunohistochemical evaluation, we compared the morphological and molecular features of S‐HCC with those of CC and HCC. S‐HCC expresses both CC‐like and stem‐cell–like genomic traits. In addition, we observed the expression of core epithelial‐mesenchymal transition (EMT)‐related genes, which may contribute to the aggressive behavior of S‐HCC. Overexpression of transforming growth factor beta (TGF‐β) signaling was also found, implying its regulatory role in the pathobiology of S‐HCC. <I>Conclusion</I>: We suggest that the fibrous stromal component in HCC may contribute to the acquisition of CC‐like gene‐expression traits in HCC. The expression of stem‐cell–like traits and TGF‐β/EMT molecules may play a pivotal role in the aggressive phenotyping of S‐HCC. (H<SMALL>EPATOLOGY</SMALL> 2012;55:1776–1786)</P>
Kim, Haeryoung,Choi, Gi Hong,Na, Deuk Chae,Ahn, Ei Young,Kim, Gwang Il,Lee, Jae Eun,Cho, Jai Young,Yoo, Jeong Eun,Choi, Jin Sub,Park, Young Nyun Wiley Subscription Services, Inc., A Wiley Company 2011 Hepatology Vol.54 No.5
<P><B>Abstract</B></P><P>There is a recently proposed subtype of hepatocellular carcinoma (HCC) that is histologically similar to usual HCC, but characterized by the expression of “stemness”‐related markers. A large‐scale study on two different cohorts of HCCs was performed to investigate the clinicopathologic features and epithelial‐mesenchymal transition (EMT)‐related protein expression status of this subtype of HCCs. The expression status of stemness‐related (e.g., keratin 19 [K19], cluster of differentiation [CD]133, epithelial cell adhesion molecule [EpCAM], and c‐kit) and EMT‐related markers (e.g., snail, S100A4, urokinase plasminogen activator receptor [uPAR], ezrin, vimentin, E‐cadherin, and matrix metalloproteinase [MMP]2) were examined using tissue microarrays from cohort 1 HCCs (n = 137). K19 protein expression in cohort 2 HCCs (n = 237) was correlated with the clinicopathologic parameters and messenger RNA (mRNA) levels of K19, uPAR, VIL2, Snail, Slug, and Twist. K19, EpCAM, c‐kit, and CD133 positivity were observed in 18.2%, 35.0%, 34.3%, and 24.8%, respectively. K19 was most frequently expressed in combination with at least one other stemness‐related marker (92.0%). K19‐positive HCCs demonstrated more frequent major vessel invasion and increased tumor size, compared to K19‐negative HCCs (<I>P</I> < 0.05). K19 was most significantly associated with EMT‐related protein expression (e.g., vimentin, S100A4, uPAR, and ezrin) (<I>P</I> < 0.05) and a poor prognosis (overall survival: <I>P</I> = 0.018; disease‐free survival: <I>P</I> = 0.007) in cohort 1. In cohort 2, HCCs with high K19 mRNA levels demonstrated higher mRNA levels of Snail, uPAR, and MMP2 (<I>P</I> < 0.05). K19‐positive HCCs demonstrated more frequent microvascular invasion, fibrous stroma, and less tumor‐capsule formation, compared to K19‐negative HCCs (<I>P</I> < 0.05). K19 expression was a significant independent predictive factor of poor disease‐free survival (<I>P</I> = 0.032). <I>Conclusion:</I> K19 was well correlated with clinicopathologic features of tumor aggressiveness, compared to other stemness‐related proteins. K19‐positive HCCs showed significantly increased EMT‐related protein and mRNA expression, suggesting that they may acquire more invasive characteristics, compared to K19‐negative HCCs through the up‐regulation of EMT‐associated genes. (H<SMALL>EPATOLOGY</SMALL> 2011;)</P>
Small-angle X-ray Scattering Beamline BL4C SAXS at Pohang Light Source II
Kwang-Woo Kim,Jehan Kim,Young Duck Yun,Hyungju Ahn,Byoungseok Min,Na Hyung Kim,Seungyu Rah,Hyo-Yun Kim,Chae-Soon Lee,In Deuk Seo,Woul-Woo Lee,Hyeong Joo Choi,Kyeong Sik Jin 한국구조생물학회 2017 Biodesign Vol.5 No.1
BL4C SAXS at the Pohang Light Source II is a small-angle X-ray scattering beamline based on an in-vacuum undulator insertion device, Si(111) DCM, and toroidal focusing mirror. The beamline normally provides high-flux synchrotron radiation X-ray sources with energies from 10.3 to 20.6 keV and a 100 µm (vertical) × 300 µm (horizontal) full width at half-maximum focal spot. The analysis of the SAXS data would be facilitated by means of useful ancillary equipment. The design of the beamline, the key components, and its role are described.
임광희(Kwang-Hee Im),이슬기(Seul-Ki Lee),김학준(Hak-Joon Kim),송성진(Sing-Jin Song),우용득(Yong-Deuk Woo),나승우(Sung-Woo Na),황우채(Woo-Chae Hwang),이형호(Hyung-Ho Lee) Korean Society for Precision Engineering 2015 한국정밀공학회지 Vol.32 No.6
A defect could be generated in bolts for a use of oil filters for the manufacturing process and then may affect to the safety and quality in bolts. Also, fine defects may be imbedded in oil filter system. So it is very important that such defects be investigated and screened during the multiple manufacturing processes. Therefore, in order effectively to evaluate the fine defects, the FEM simulations were performed to make characterization in the crack detection of the bolts and the parameters such as number of turns of the coil, the coil size, applied frequency were calculated based on the simulation results. Simulations were carried out for the defect signal of eddy current probe. Exciter and receiver were utilized. In this paper, the FEM simulations were performed in both bobbin-type and pancake-type probe, both probes were optimized under Eddy current FEM simulations and the results of calculation were discussed.