• Journal of Embryo Transfer
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• v.32 no.3
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• pp.193-200
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• 2017

The purpose of this study is to confirm whether spontaneous adipocyte generation during chondrogenic induction culture affects the chondrogenic differentiation of porcine skin-derived stem cells (pSSCs). For this purpose, chondrogenic differentiation characteristics and specific marker gene expression were analyzed using cell lines showing different characteristics of spontaneous adipocyte formation. Of the four different lines of pSSCs, the pSSCs-IV line showed higher Oil red O (ORO) and glycosaminoglycan (GAG) extraction levels. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the levels of adipogenic markers peroxisome proliferator-activated receptor gamma 2 ($PPAR{\gamma}2$) and adipocyte Protein 2 (aP2) mRNAs were significantly higher in pSSCs-IV than those of the other pSSC lines (P<0.05). Among three chondrogenic markers, collagen type II (Col II) and sex determining region Y-box (Sox9) mRNAs were strongly expressed in pSSCs-IV (P<0.05), but not in aggrecan (Agg), which was significantly higher in pSSCs-II (P<0.05). These results demonstrate that the spontaneous adipocyte generation during chondrogenic differentiation has a positive effect on the chondrogenesis of pSSCs. More research is needed on the correlation between adipocyte generation and cartilage formation.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.263-271
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• 2009

Cardiovascular diseases (CVDs) are one of the most cause of death around the world and fields of interest for cardiac stem cells. Also, current use of terminally differentiated adult cardiomyocytes for CVDs has limited regenerative capacity therefore any significant cell loss may result in the development of progressive heart failure. Human embryonic stem cells (hESCs) derived from blastocyst-stage embryos spontaneously have ability to differentiate via embryo-like aggregates (endoderm, ectoderm and mesoderm) in vitro into various cell types including cardiomyocyte. However, most effective molecule or optimized condition which can induce cardiac differentiation of hESCs is rarely studied. In this study, we developed both spontaneous and inductive cardiomyocyte-like cells differentiation from hESCs by treatment of induced-factors, 5-azacytidine, BMP-4 and cardiogenol C. On the one hand, spontaneous and inductive cardiomyocyte-like cells showed that cardiac markers are expressed for further analysis by RT-PCR and immunocytochemistry. Interestingly, BMP-4 greatly improved homogeneous population of the cardiomyocyte-like cells from hESCs CHA15 and H09. In conclusion, we verified that spontaneously differentiated cells showed cardiac specific markers which characterize cardiac cells, treated extrinsic factors can manage cellular signals and found that hESCs can undergo differentiation into cardiomyocytes better than spontaneous group. This finding offers an insight into the inductive factor of differentiated cardiomyocytes and provides some helpful information that may offer the potential of cardiomyocytes derived from hESCs using extrinsic factors.

• Korean Journal of Pharmacognosy
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• v.24 no.2
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• pp.131-139
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• 1993

These studies were conducted to investigate the effects of the extracts from Hoelen alba, Alismatis Rhizoma and Atractylodes Rhizoma on the proliferation and differentiation of 3T3-L1 cells. The results were summerized as follows: Hoelen alba and Alismatis Rhizoma extracts inhibited the proliferation of preadipose 3T3-L1 cells. In inductive differentiation, all three extracts inhibited the adipose conversion in 2 days of initial-culture, Atractylodes Rhizoma extract inhibited the adipose conversion in 5 days of final-culture and Hoelen alba and Alismatis Rhizoma inhibited adipose conversion in treatment of whole term of culture. In spontaneous differentiation, Atractylodes Rhizoma extract increased the adipose conversion in 2 days of initial-culture, Hoelen alba and Alismatis Rhizoma increased the adipose conversion in 5 days of final-culture, all three extracts increased adipose conversion in treatment of whole term of culture. The 10% serum of mice treated with each sample did not affect, but the 5% serum of them inhibited the proliferation of 3T3-L1 cells. In inductive differentiation, the 10% serum of them inhibited the adipose conversion in treatment of whole term of culture.

• Animal cells and systems
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• v.13 no.2
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• pp.235-245
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• 2009

Embryonic stem (ES) cells have a capability to generate all types of cells. However, the mechanism by which ES cells differentiate into specific cell is still unclear. Using microarray technology, the differentiation process in mouse embryonic stem cells was characterized by temporal gene expression changes of mouse ES cells during differentiation in a monolayer culture. A large number of genes were differentially regulated from 1 day to 14 days, and less number of genes were differentially expressed from 14 days to 28 days. The number of up-regulated genes was linearly increased throughout the 28 days of in vitro differentiation, while the number of down-regulated genes reached the plateau from 14 days to 28 days. Most differentially expressed genes were functionally classified into transcriptional regulation, development, extra cellular matrix (ECM),cytoskeleton organization, cytokines, receptors, RNA processing, DNA replication, chromatin assembly, proliferation and apoptosis related genes. While genes encoding ECM proteins were up-regulated, most of the genes related to proliferation, chromatin assembly, DNA replication, RNA processing, and cytoskeleton organization were down-regulated at 14 days. Genes known to be associated with embryo development or transcriptional regulation were differentially expressed mostly after 14 days of differentiation. These results indicate that the altered expression of ECM genes constitute an early event during the spontaneous differentiation, followed by the inhibition of proliferation and lineage specification. Our study might identify useful time-points for applying selective treatments for directed differentiation of mouse ES cells.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.20-20
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• 2002

This study was to establish the use of parthenogenetic mouse ES (P-mES02) cells as a reproducible differentiation system for mouse cardiomyocytes. To induce differentiation, P-mES02 cells were dispersed by dissociation and the formation of ES cell aggregates in differentiation medium. After 7 days in differentiation culture, the embryoid bodies (EBs) were plated onto gelatin-coated dish. Cultures were observed daily using an inverted light microscope to determine the day of contraction onset and total duration of continuous contractile activity for each contracting focus. (omitted)

• Animal cells and systems
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• v.1 no.1
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• pp.63-69
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• 1997

We have previously reported that NF-kB is involved in the regulation of nitric oxide synthase gene expression during differentiation of chick embryonic myoblasts. However, how NF-kB is timely activated during myogenesis remains elusive. One of the most prominent events in myogenesis is myoblast membrane fusion, which is accompanied with massive cytoskeletal reorganization. Here we show that the activity of NF-kB markedly increases in L6 rat myogenic cells that have just initiated morphological changes by treating nocodazole, a microtubule-disrupting agent. Furthermore, the induction of NF-kB activation was closely correlated with the myoblast fusion. In addition, a variety of agents that disrupt microtubules stimulated the myoblast fusion as well as the induction of NF-kB activation. In contrast, taxol, a microtubule-stabilizing agent, suppressed the induction of NF-kB activation and inhibited spontaneous differentiation of L6 cells as well. In addition, we found that the NF-KB in the cells consists of p50/p65 heterodimers. These results support the idea that reorganization of microtubule at early stages of differentiation plays a role as a signal for NF-KB activation during myogenesis.

• Annals of Clinical Neurophysiology
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• v.25 no.1
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• pp.10-18
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• 2023

The ultimate purpose of eye movement is to maintain clear vision by ensuring that images of observed objects are focused on the fovea in the retina. Accurate evaluation of ocular movements, including nystagmus and saccadic intrusions, provides very useful information for determining the overall function and abnormality of the complex oculomotor system, from the peripheral vestibular system to the cerebrum. Eye movement tests are therefore essential for the accurate diagnosis of patients who complain of dizziness and imbalance. They help to predict lesion locations from the peripheral vestibular system to the central cerebral cortex and play an important role in differentiation from other diseases. The methodology of recording and interpreting ocular movements using video-oculography are described in this review article.

• BMB Reports
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• v.39 no.4
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• pp.426-431
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• 2006

Embryonic stem cells (ESCs), representing a population of undifferentiated pluripotent cells with both self-renewal and multilineage differentiation characteristics, are capable of spontaneous differentiation into cardiomyocytes. The present study sought to define the kinetic characterization of lactate dehydrogenase (LDH) and creatine kinase (CK) of ESC- and neonatal-derived cardiomyocytes. Spontaneously differentiated cardiomyocytes from embryoid bodies (EBs) derived from mouse ESC line (Royan B1) and neonatal cardiomyocytes were dispersed in a buffer solution. Enzymes were extracted by sonication and centrifugation for kinetic evaluation of LDH and CK with spectrophotometric methods. While a comparison between the kinetic properties of the LDH and CK of both groups revealed not only different Michaelis constants and optimum temperatures for LDH but also different Michaelis constants and optimum pH for CK, the pH profile of LDH and optimum temperature of CK were similar. In defining some kinetic properties of cardiac metabolic enzymes of ESC-derived cardiomyocytes, our results are expected to further facilitate the use of ESCs as an experimental model.

• Reproductive and Developmental Biology
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• v.32 no.4
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• pp.211-215
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• 2008

The HMG box containing protein (HBP) has a high mobility group domain and involved in the regulation of proliferation and differentiation of tissues. We screened HBP2 in glioblastoma using Suppression Subtractive Hybridization (SSH) and isolated human spermatogonial stem cell-like cells (hSSC-like cells) derived from patients of nonobstructive azoospermia (NOA). Expression of HBP2 was analyzed by RT-PCR in undifferentiated stem cells (human Embryonic Stem Cells, hSSC-like cells 2P) and spontaneous differentiated stem cells (hSSC-like cells 4P). It was overexpressed in hESC and hSSC-like cells 2P but not in hSSC-like cells 4P. Also, the expression level of HBP2 was downregulated in colon tumor tissues compared to normal tissues. Specifically in synchronized WI-38 cells, HBP2 was highly upregulated until the G1 phase of the cell cycle and gradually decreased during the S phase. Our results suggest that HBP2 was downregulated during the spontaneous differentiation of hSSC-like cells. HBP2 was differently expressed in colon tissues and was related to G1-progression in WI-38 cells. It may playa role in the maintenance of an undifferentiated hSSC-like cell state and transits from G1 to S in WI-38 cells. This research was important that it identified a biomarker for an undifferentiated state of hSSC-like cells and characterized its involvement to arrest during cell cycle in colon cancer.

• International Journal of Stem Cells
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• v.16 no.3
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• pp.293-303
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• 2023

Background and Objectives: The physiological oxygen tension in fetal brains (~3%, physioxia) is beneficial for the maintenance of neural stem cells (NSCs). Sensitivity to oxygen varies between NSCs from different fetal brain regions, with midbrain NSCs showing selective susceptibility. Data on Hif-1𝛼/Notch regulatory interactions as well as our observations that Hif-1𝛼 and oxygen affect midbrain NSCs survival and proliferation prompted our investigations on involvement of Notch signalling in physioxia-dependent midbrain NSCs performance. Methods and Results: Here we found that physioxia (3% O₂) compared to normoxia (21% O₂) increased proliferation, maintained stemness by suppression of spontaneous differentiation and supported cell cycle progression. Microarray and qRT-PCR analyses identified significant changes of Notch related genes in midbrain NSCs after long-term (13 days), but not after short-term physioxia (48 hours). Consistently, inhibition of Notch signalling with DAPT increased, but its stimulation with Dll4 decreased spontaneous differentiation into neurons solely under normoxic but not under physioxic conditions. Conclusions: Notch signalling does not influence the fate decision of midbrain NSCs cultured in vitro in physioxia, where other factors like Hif-1𝛼 might be involved. Our findings on how physioxia effects in midbrain NSCs are transduced by alternative signalling might, at least in part, explain their selective susceptibility to oxygen.