• International Journal of Molecular Medicine
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• 제43권2호
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• pp.1033-1040
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• 2019

Protein kinase casein kinase 2 (CK2) is important in the regulation of cell proliferation and death, even under pathological conditions. Previously, we reported that CK2 regulates the expression of heme oxygenase-1 (HO-1) in stress-induced chondrocytes. In the present study, it was shown that CK2 is involved in the dedifferentiation and cellular senescence of chondrocytes. Treatment of primary articular chondrocytes with CK2 inhibitors, 4,5,6,7-terabromo-2-azabenzimidazole (TBB) or 5,6-dichlorobenzimidazole 1-β-D-ribofuranoside (DRB), induced an increase in senescence-associated β-galactosidase (SA-β-gal) staining. In addition, TBB reduced the expression of type II collagen and stimulated the accumulation of β-catenin, phenotypic markers of chondrocyte differentiation and dedifferentiation, respectively. It was also observed that the abrogation of CK2 activity by CK2 small interfering RNA induced phenotypes of chondrocyte senescence. The association between HO-1 and cellular senescence was also examined in CK2 inhibitor-treated chondrocytes. Pretreatment with 3-morpholinosydnonimine hydrochloride, an inducer of the HO-1 expression, or overexpression of the HO-1 gene significantly delayed chondrocyte senescence. These results show that CK2 is associated with chondrocyte differentiation and cellular senescence and that this is due to regulation of the expression of HO-1. Furthermore, the findings suggest that CK2 is crucial as an anti-aging factor during chondrocyte senescence.

• Animal cells and systems
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• 제6권1호
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• pp.69-74
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• 2002

Recent evidence has suggested that trunk neural crest cell generally assumed to have equivalent differentiation potentials, demonstrate differentiation bias along the anterior/posterior axis. In amphibian and fish, neural crest cells give rise to three chromatophore types, melanophores, xantho-phores, and iridophores. Each pigment cell type has distinct characteristics but there is speculation about the cellular plasticity that exists among them. Neural crest cells migrate along specific routes, ventromedially and dorsolaterally. Neural crest cells that travel dorsolaterally are the first cells to begin migration in the axolotl and are the major contributors to the visible pigment pattern. Many factors and mechanisms that are responsible for guiding migratory neural crest cells along potential pathways or determining their fate remain unknown. A single lineage of the crest, which becomes restricted to one of the three pigment cell types, gives us the opportunity to examine the existence of neural crest stem cell populations and cellular plasticity. Study presented here showed results from recent in vitro studies designed to identify parameters influencing differentiation events of individual neural crest-derived pigment cell lineages. Melanophore production from neural crest explants originating from different levels along the anterior/posterior axis of wild type-axolotl embryos were compared and demonstrate that the differentiation of melanophores is enhanced in subpopulation of neural crest treated with forskolin. Forskolin (an adenylate cyclase activator) increases intracellular CAMP concentration and eventually activates the protein kinase-A signaling pathway. Melanophore number, melanin content, and tyrosinase activity in explants taken from the anterior-most region of the crest increased significantly in response to forskolin treatment. This study suggests implications of region specific influences and developmental regulation in the development of pigment pattern.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.509-510
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• 1989

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.136.2-136
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• 1996

No Abstract, See Full Text

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.470-480
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• 2000

The epithelium of odontogenic cyst seems to be in a specific status of cellular proliferation and cytodifferentiation. With the identification of various genes, which play essential roles in the specific stages of cellular proliferation and differentiation, the cellular conditions of odontogenic cyst epithelium need to be reevaluated. This study aimed to estimate the degree of proliferating, differentiating and apoptotic activities of odontogenic cyst epithelium using antisera of PCNA, Ki-67, MPM-2, transglutaminase C, heat shock protein 70 and $ApopTag$^{(R)}$. method in 19 cases of odontogenic cysts. Cellular changes of the cyst epithelium were measured by intensity of each immunohistochemical staining. Results were as follows: 1. The proliferating activity of the cyst epithelium was slightly lower than that of normal oral mucosal epithelium, with the use of primary antibodies against PCNA, Ki-67, and MPM-2. And the proliferating activity of the epithelium in OKC group was even higher than that of the epithelium in non-OKC group. 2. The odontogenic cysts showed weakly positive reaction with transglutaminase C, but strongly positive reaction with HSP 70. 3. Occasionally, only a few apoptotic cell was observed in the superficial keratin layer of OKC. 4. The hyperplastic cyst epithelium infiltrated with mild inflammatory cells showed diffusely positive reaction with different proliferating factors. From the above results, we presumed that the endogenous proliferating and differentiating activity of the cyst epithelium was slightly lower than that of normal oral mucosal epithelium, and also supposed that the cyst epithelium could be reactivated for the further proliferation by the exogenous factors, such as inflammatory reaction and any chemicophysical irritations.

• Molecules and Cells
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• 제37권9호
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• pp.650-655
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• 2014

Mesenchymal stem cells (MSCs) can differentiate into neural cells to treat nervous system diseases. Magnetic resonance is an ideal means for cell tracking through labeling cells with superparamagnetic iron oxide (SPIO). However, no studies have described the neural differentiation ability of SPIO-labeled MSCs, which is the foundation for cell therapy and cell tracking in vivo. Our results showed that bone marrow-derived mesenchymal stem cells (BM-MSCs) labeled in vitro with SPIO can be induced into neural-like cells without affecting the viability and labeling efficiency. The cellular uptake of SPIO was maintained after labeled BM-MSCs differentiated into neural-like cells, which were the basis for transplanted cells that can be dynamically and non-invasively tracked in vivo by MRI. Moreover, the SPIO-labeled induced neural-like cells showed neural cell morphology and expressed related markers such as NSE, MAP-2. Furthermore, whole-cell patch clamp recording demonstrated that these neural-like cells exhibited electrophysiological properties of neurons. More importantly, there was no significant difference in the cellular viability and $[Ca^{2+}]_i$ between the induced labeled and unlabeled neural-like cells. In this study, we show for the first time that SPIO-labeled MSCs retained their differentiation capacity and could differentiate into neural-like cells with high cell viability and a good cellular state in vitro.

• BMB Reports
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• 제50권2호
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• pp.103-108
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• 2017

Heme oxygenase (HO-1) catalyzes heme to carbon monoxide (CO), biliverdin/bilirubin, and iron and is known to prevent the pathogenesis of several human diseases. We assessed the beneficial effect of heme degradation products on osteoclastogenesis induced by receptor activator of NF-${\kappa}B$ ligand (RANKL). Treatment of RAW264.7 cells with CORM-2 (a CO donor) and bilirubin, but not with iron, decreased RANKL-induced osteoclastogenesis, with CORM-2 having a more potent anti-osteogenic effect. CORM-2 also inhibited RANKL-induced osteoclastogenesis and osteoclastic resorption activity in marrow-derived macrophages. Treatment with hemin, a HO-1 inducer, strongly inhibited RANKL-induced osteoclastogenesis in wild-type macrophages, but was ineffective in $HO-1^{+/-}$ cells. CORM-2 reduced RANKL-induced NFATc1 expression by inhibiting IKK-dependent NF-${\kappa}B$ activation and reactive oxygen species production. These results suggest that CO potently inhibits RANKL-induced osteoclastogenesis by inhibiting redox-sensitive NF-${\kappa}B$-mediated NFATc1 expression. Our findings indicate that HO-1/CO can act as an anti-resorption agent and reduce bone loss by blocking osteoclast differentiation.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.156.1-156.1
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• 2003

Cerarmide acts as a lipid second messenger in the cellular signal transduction and is involved in mediating a variety of cell functions such as proliferation, differentiation, growth arrest, and apoptosis. In the present study, we have investigated the effect of ceramide on cellular cytotoxity and reactive oxygen species (ROS) to understand the relationship between them. Ceramide treatment significantly increased cell death in RAW 264.7 murine macrophages activated with lipopolysaccharide (LPS) and interferon-g (IFN-g). (omitted)

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.331-338
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• 2011

MicroRNAs (miRNAs) function as a key regulator of diverse cellular functions. To find out novel miRNAs that promote the differentiation of mouse embryonic stem cells (mESCs), we compared the miRNAs expression profiles of mESCs under self-renewal vs. differentiation states. We noticed that miR-222 was highly expressed during the differentiation of mESCs. Quantitative RT-PCR analysis revealed that expression of miR-222 was up-regulated during the embryonic bodies formation and retinoic acid -dependent differentiation. When miR-222 was suppressed by antogomiR-222, the differentiation of mESCs was delayed compared to control. Self-renewal marker expression or cell proliferation was not affected but the expression of lineage specific marker was suppressed by the treatment of miR-222 inhibitor during the differentiation of mESCs. Taken together, these results suggest that miR-222 functions to promote the differentiation of mESCs by regulating expression of differentiation related genes.

• Molecules and Cells
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• 제21권2호
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• pp.294-301
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• 2006

We have previously reported that phosphorylation of eukaryotic elongation factor 2 (eEF2) is related to the differentiation of chick embryonic muscle cells in culture. In the present study, we found that eEF2 phosphorylation declined shortly after induction of differentiation of L6 myoblasts, when the cells prepare for terminal differentiation by withdrawing from the cell cycle. This decrease in phosphorylation was prevented by inhibitors of phosphoinositide 3-kinase (PI3-kinase) that strongly inhibit myoblast differentiation. We hypothesized that PI3-kinase plays an important role in myoblast differentiation by regulating eEF2 phosphorylation in the early stages of differentiation. To test this hypothesis, myoblasts were synchronized at in $G_2/M$ and cultured in fresh differentiation medium (DM) or growth medium (GM). In DM the released cells accumulated in $G_0$/$G_1$ while in GM they progressed to S phase. In addition, cyclin D1 was more rapidly degraded in DM than in GM, and eEF2 phosphorylation decreased more. Inhibitors of PI3-kinase increased eEF2 phosphorylation, but PI3-kinase became more activated when eEF2 phosphorylation declined. These results suggest that the regulation of L6 myoblast differentiation by PI3-kinase is related to eEF2 phosphorylation.