• Animal cells and systems
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• v.5 no.3
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• pp.205-209
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• 2001

Mesenchymal cells from the leg buds of stage 24-chick embryos differentiated into chondrocytes when plated at high density. Treatment of high density micromass culture of chick mesenchymal cells with cytochalasin D(CD, 2 $\mu$M for 24 h) resulted in inhibition of chondrogenesis. CD treatment was found to affect the expression of the contractile protein $\alpha$-smooth muscle actin ($\alpha$-SM actin). In control cultures, $\alpha$-SM actin uniformly expressed from culture day 2, but the CD-treated cells induced expression of $\alpha$-SM actin from the first day of culture followed by a continuous increase. Expression of pan-cadherin (P-cadherin) decreased as chondrogenesis proceeded in the control culture, whereas the CD-treated cells showed sustained expression. These results propose a close connection of chondrogenic differentiation with expression of $\alpha$-SM actin and P-cadherin.

• The Korean Journal of Zoology
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• v.30 no.4
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• pp.410-416
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• 1987

The effect of heavy metal ions on the synthesis of proteins in cultured chick embryonic muscle cells were examined by labeling the cellular proteins with 35S-methionine and the surface proteins with Nalssl and lactoperokidase. The protein pattern in the cells cultured for 48 hrs showed little or no difference whether or not the cells were treated with any of the metal ions including Cu2+, Cd2+ and Hg2+, which are known to block the fusion of mypblasts. However, a 43kd protein disappeared from the control cells cultured for 72 hrs but remained unchanged in the cells treated with the metal ions. When analyzed for the syntheiic pattern of membrane proteins, addition of the ions (particularly of Cda+ and Cr3+) caused a marked increase in the level of 66kd protein, as compared to that in the untreated cells. By contrast, the level of 29kd protein was much higher in the control cells than in the cells treated with the metal ions. These results suggest that the heavy metal ions appear to block the degradation of 43kd soluble protein and 66kd membrane protein, perhaps by inhibiting a metalloprotease, which may be essential for the myogenic process of embryonic muscle cells.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.33-40
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• 2001

Objective: This study was to establish the human embryonic stem (ES) cells derived from frozen-thawed blastocyst stage embryo that were destined to be discarded after five years in routine human IVF-ET program. Methods: Frozen-thawed and survived human blastocysts were treated by immunosurgery, and recovered ICM cells were cultured onto STO feeder cell layer and ICM colony was subcultured by mechanical dissociation into clumps. To identify ES cell, alkaline phosphatase staining and expression of Oct4 in replated ICM colonies were examined. Also, to examine the possibility of ES cell differentiation, retinoic acid (RA), basic fibroblast growth factor (b-FGF), nerve growth factor (NGF) were added in culture medium. In addition, to classify the specific cell type, differentiated cells were stained by indirect immunocytochemistry. Results: One ICM colony recovered from frozen-thawed six blastocysts was subcultured, continuously replated during 40 passage culture duration without differentiation. Subcultured colonies were strong positively stained by alkaline phophatase. When the expression of Oct4 in cultured ES colony was examined, Oct4b type is more clearly indicated than Oct4a one although there was not detected in embryoid body or differentiated cells. In differentiated cardiomyocytes from ES colony, cells were beaten regularly (60 times/min). In differentiated neural cells from ES colony, neurofilament (NF) 200 kDa protein, microtubule associated protein (MAP) 2 and ${\beta}$-tubulin of specific marker in neurons, glial fibrillary acidic protein (GFAP) of specific marker in astrocytes and galactocelebrocide (GalC) of specific marker in oligodendrocytes were confirmed by indirect immunocytochemistry. Also, muscle cells were detected by indirect immunocytochemistry. In addition, ES colonies can be successfully cryopreserved. Conclusion: This study suggested that establishment of human ES cells can be successfully derived from frozen-thawed blastocysts that were destined to be discarded, and obtained specific cell types (cardiomyocytes, neurons and muscle cells) through the in vitro differentiation procedures of ES cells.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.225-232
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• 2013

Satellite cells were derived from muscular tissue in postnatal pig. Satellite cell is an important to growth and development in animal tissues or organs. However, the progress underlying induced differentiation is not clear. The aim of this study was to evaluate the morphologic and the transcriptome changes in porcine satellite cell (PSC) treated with insulin, rosiglitazone, or dexamethasone respectively. PSC was obtained from postnatal muscle tissue. In study 1, for study the effect of insulin and FBS on the differentiated satellite cells, cells were cultured at absence or presence of insulin treated with FBS. Total RNA was extracted for determining the expression levels of myogenic PAX3, PAX7, Myf5, MyoD, and myogenin genes by real-time PCR. Myogenic genes decreased expression levels of mRNA in treated with insulin. In study 2, in order to clarify the relationship between rosiglitazone and lipid in differentiated satellite cells, we further examined the effect of FBS on lipid accumulation in the presence or absence of the rosiglitazone and lipid. Significant differences were observed between rosiglitazone and lipid by FBS. The mRNA of FABP4 and $PPAR{\gamma}$ increased in rosiglitazone treatment. In study 3, we examined the effect of dexamethasone on osteogenic differentiation in PSC. The mRNA was increased osteoblasotgenic ALP and ON genes treated with dexamethasone in 2% FBS. Dexamethasone induces osteoblastogenesis in differentiated PSC. Taken together, in differentiated PSCs, FABP4 and $PPAR{\gamma}$ increased to rosiglitazone. Whereas, no differences to FBS and lipid. These results were not comparable with previous reports. Our results suggest that adipogenic, myogenic, and osteoblastogenic could be isolated from porcine skeletal muscle, and identify culture conditions which optimize proliferation and differentiation formation of PSC.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.659-667
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• 2020

Muscle stem cells isolated from domestic animals, including cows and pigs, were recently spotlighted as candidates for the production of alternative protein resources, so-called cultured meat or lab-grown meat. In the present study, we aimed to optimize the in vitro culture conditions for the long-term expansion of pig muscle stem cells via the screening of various signaling molecules. Pig muscle stem cells were collected from the biceps femoris muscles of 3-d-old crossbred pigs (Landrace×Yorkshire×Duroc, LYD) and cultured in minimum essential medium-based growth media. However, the pig muscle stem cells gradually lost their proliferation ability and featured morphologies during the long-term culture over two weeks. To find suitable in vitro culture conditions for an extended period, skeletal muscle growth medium-2, including epidermal growth factor (EGF), dexamethasone, and a p38 inhibitor (SB203580), was used to support the stemness of the pig muscle stem cells. Interestingly, pig muscle stem cells were stably maintained in a long-term culture without loss of the expression of myogenic marker genes as determined by PCR analysis. Immunostaining analysis showed that the stem cells were capable of myogenic differentiation after multiple passaging. Therefore, we found that basal culture conditions containing EGF, dexamethasone, and a p38 inhibitor were suitable for maintaining pig muscle stem cells during expanded culture in vitro. This culture method may be applied for the production of cultured meat and further basic research on muscle development in the pig.

• Journal of Genetic Medicine
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• v.14 no.2
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• pp.75-79
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• 2017

Duchenne and Becker muscular dystrophies (DMD and BMD, respectively) are X-linked neuromuscular disorders characterized by progressive muscle weakness and severe skeletal muscle degeneration. BMD is a milder form with a later onset. Patients with BMD tend to survive much longer than those with DMD. The differentiation between DMD and BMD is important in the genetic counseling of affected patients and their families. Since muscle biopsies are invasive procedures, the differential diagnosis of BMD and DMD is often dependent on the mutation identified in the DMD gene in affected patients. However, when a novel DMD mutation is identified, the differential diagnosis should be based on muscle biopsy findings with other clinical findings. Here we describe two Korean patients with BMD confirmed by muscle biopsy and genetic testing. Two novel exonic deletions in the DMD gene were identified.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2525-2528
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• 2013

The Homer protein family, also known as the family of cytoplasmic scaffolding proteins, which include three subtypes (Homer1, Homer2, Homer3). Homer3 can regulate transcription and play a very important role in the differentiation and development for some tissues (e.g. muscle and nervous systems). The current studies showed that Homer3 abnormal expression changes in acute myeloid leukemia (AML). Forced expression of Homer3 in transfected K562 cells inhibited proliferation, influenced the cell cycle profile, affected apoptosis induced by $As_2O_3$ through inhibition of Bcl2 expression, and also promoted cell differentiation induced by 12-O-tetra decanoylphorbol-acetate (TPA). These results showed that Homer3 is a novel gene which plays a certain role in the occurrence and development of AML.

• Molecules and Cells
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• v.25 no.4
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• pp.479-486
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• 2008

Mitogen-activated protein kinases (MAPKs) play an indispensable role in activation of the myogenic program, which is responsive to mechanical stimulation. Although there is accumulating evidence of mechanical force-mediated cellular responses, the role of MAPK in regulating the myogenic process in myoblasts exposed to cyclic stretch is unclear. Cyclic stretch induced the proliferation of C2C12 myoblasts and inhibited their differentiation into myotubes. In particular, it induced persistent phosphorylation of p38 kinase, and decreased the level of phosphorylation of extracellular-signal regulated kinase (ERK). Partial inhibition of p38 phosphorylation increased cellular levels of MyoD and p-ERK in stretched C2C12 cells, along with increased myotube formation. Treatment with $10{\mu}M$ PD98059 prevented myogenin expression in response to a low dose of SB203580 ($3{\mu}M$) in the stretched cells, suggesting that adequate ERK activation is also needed to allow the cells to differentiate into myotubes. These results suggest that cyclic stretch inhibits the myogenic differentiation of C2C12 cells by activating p38-mediated signaling and inhibiting ERK phosphorylation. We conclude that p38 kinase, not ERK, is the upstream signal transducer regulating cellular responses to mechanical stretch in skeletal muscle cells.

• Journal of Life Science
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• v.21 no.1
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• pp.36-43
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• 2011

Diabetes mellitus is associated with vascular complications. Diabetic patients exhibit high levels of glycated adducts in serum compared to non-diabetic individuals. The aim of this study was to investigate whether extracellular glycated albumin (GA) predisposes vascular smooth muscle cells (VSMCs) to pro-inflammatory phenotype. Exposure of rat aortic smooth muscle cells (AoSMCs) to GA not only enhanced interleukin-6 (IL-6) release but also activated promoter activity of the IL-6 gene. GA-induced IL-6 promoter activation was suppressed by dominant-negative forms of Toll-like receptor (TLR)-4 and myeloid differentiation factor 88 (MyD88), but not by dominant-negative-forms of TLR-2 and TIR-domain-containing adapter-inducing interferon-$\beta$ (TRIF). Extracellular signal-regulated kinase (ERK) inhibition and diphenyleneiodium (DPI) also attenuated IL-6 induction by GA. Mutation at the nuclear factor-${\kappa}B$ (NF-${\kappa}B$)-binding site in the IL-6 promoter region suppressed promoter activation in response to GA. The present study proposes that GA would contribute to inflammatory reaction in the stressed vasculature by inducing IL-6 in VSMCs, and that TLR-4, EKR, and NF-${\kappa}B$ play active roles in the process.

• Journal of Life Science
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• v.31 no.9
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• pp.856-861
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• 2021

CD82/KAI1, identified as a metastasis suppressor, was initially known only as a molecular facilitator, but its various functions have recently been revealed. CD82 plays an important role in the stem-progenitor cell, angiogenesis, and muscle. We would like to introduce the recently reported functions and roles of CD82 in this review. CD82 is a member of the tetraspanin family, which consists of four transmembrane domains. The interaction between CD82 and cell adhesion molecules suppresses the metastasis of cancer. CD82 regulates the cell cycle of stem-progenitor cells in the stem cell niche. In the bone marrow, CD82 is expressed on long-term repopulating hematopoietic stem cells (LT-HSCs), which show multipotent differentiation potential. The interaction between CD82 and Duffy antigen receptor for chemokines (DARC) induces quiescence in LT-HSCs. CD82 also regulates Rac1 activity, resulting in the homing and engraftment of HSCs into the bone marrow niche. Besides, CD82 maintains the differentiation potential of muscle stem cells and prevents angiogenesis by inhibiting the expression of cytokines, such as IL-6 and VEGF and adhesion molecules in endothelial cells. CD82 is a key membrane protein that distinguishes the hierarchy of stem-progenitor cells, and is also important for amplification and verification of cellular resources. Further studies on the function of CD82 in various organs and cells are expected to advance cell biology and cell therapy.