• 제목/요약/키워드: cell differentiation

검색결과 2,861건 처리시간 0.045초

The Role of Stress Granules in the Neuronal Differentiation of Stem Cells

  • Jeong, Sin-Gu;Ohn, Takbum;Jang, Chul Ho;Vijayakumar, Karthikeyan;Cho, Gwang-Won
    • Molecules and Cells
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    • 제43권10호
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    • pp.848-855
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    • 2020
  • Cells assemble stress granules (SGs) to protect their RNAs from exposure to harmful chemical reactions induced by environmental stress. These SGs release RNAs, which resume translation once the stress is relieved. During stem cell differentiation, gene expression is altered to allow cells to adopt various functional and morphological features necessary to differentiate. This process induces stress within a cell, and cells that cannot overcome this stress die. Here, we investigated the role of SGs in the progression of stem cell differentiation. SGs aggregated during the neuronal differentiation of human bone marrow-mesenchymal stem cells, and not in cell lines that could not undergo differentiation. SGs were observed between one and three hours post-induction; RNA translation was restrained at the same time. Immediately after disassembly of SGs, the expression of the neuronal marker neurofilament-M (NF-M) gradually increased. Assembled SGs that persisted in cells were exposed to salubrinal, which inhibited the dephosphorylation of eukaryotic translation initiation factor 2 subunit 1 (eIF2α), and in eIF2α/S51D mutant cells. When eIF2α/S51A mutant cells differentiated, SGs were not assembled. In all experiments, the disruption of SGs was accompanied by delayed NF-M expression and the number of neuronally differentiated cells was decreased. Decreased differentiation was accompanied by decreased cell viability, indicating the necessity of SGs for preventing cell death during neuronal differentiation. Collectively, these results demonstrate the essential role of SGs during the neuronal differentiation of stem cells.

Expression of Bone Morphogenetic Protein-2 and Histological Differentiation of Oral Squamous Cell Carcinomas

  • Hamasni, Fatme Mouchref;El Hajj, Fady
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권12호
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    • pp.5243-5245
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    • 2016
  • Background and Objective : Bone morphogenic protein-2 (BMP-2) plays an essential role in mesenchymal cell differentiation into osteoblasts، through many intracellular pathways which may also be active in tumors. Invasive oral squamous cell carcinomas account for more than 90% of head and neck malignancies in many cancer registries. They are classified into three types according to epithelial cell differentiation. The present study aimed to identify any relation between BMP-2 expression and tumor histology. Materials and methods: BMP-2 expression was compared immunohistochemically among 30 cases (19 male and 11 female, mean age 48 years) of oral squamous cell carcinoma, Division was into 3 groups (each containing 10 cases) according to the histological grade. Results: No significant correlation between BMP-2 expression and histological grade was observed. Changes in localization and cytoplasmic staining were also not apparent. Conclusion: From the results of this study BMP-2 does not appear to have any application as a prognostic marker for oral squamous cell carcinomas.

Alteration of Apoptosis during Differentiation in Human Dental Pulp-Derived Mesenchymal Stem Cell

  • Lee, Hyeon-Jeong;Park, Byung-Joon;Jeon, Ryoung-Hoon;Jang, Si-Jung;Son, Young-Bum;Lee, Sung-Lim;Rho, Gyu-Jin;Kim, Seung-Joon;Lee, Won-Jae
    • 한국동물생명공학회지
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    • 제34권1호
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    • pp.2-9
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    • 2019
  • Because mesenchymal stem cells (MSCs) maintain distinct capacities with respect to self-renewal, differentiation ability and immunomodulatory function, they have been highly considered as the therapeutic agents for cell-based clinical application. Of particular, differentiation condition alters characteristics of MSCs, including cellular morphology, expression of gene/protein and cell surface molecule, immunological property and apoptosis. However, the previous results for differentiation-related apoptosis in MSCs have still remained controversial due to varied outcomes. Therefore, the present study aimed to disclose periodical alterations of pro- and anti-apoptosis in MSCs under differentiation inductions. The human dental pulp-derived MSCs (DP-MSCs) were differentiated into adipocytes and osteoblasts during early (1 week), middle (2 weeks) and late (3 weeks) stages, and were investigated on their apoptosis-related changes by Annexin V assay, qRT-PCR and western blotting. The ratio of apoptotic cell population was significantly (p < 0.05) elevated during the early to middle stages of differentiations but recovered up to the similar level of undifferentiated state at the late stage of differentiation. In the expression of mRNA and protein, whereas expressions of pro-apoptosis-related makers (BAX and BAK) were not altered in any kind and duration of differentiation inductions, anti-apoptosis marker (BCL2) was significantly (p < 0.05) elevated even at the early stage of differentiations. The recovery of apoptotic cell population at the late stage of differentiation is expected to be associated with the response by elevation of anti-apoptotic molecules. The present study may contribute on understanding for cellular mechanism in differentiation of MSCs and provide background data in clinical application of MSCs in the animal biotechnology to develop effective and safe therapeutic strategy.

Neoagarohexaose-mediated activation of dendritic cells via Toll-like receptor 4 leads to stimulation of natural killer cells and enhancement of antitumor immunity

  • Lee, Moon Hee;Jang, Jong-Hwa;Yoon, Gun Young;Lee, Seung Jun;Lee, Min-Goo;Kang, Tae Heung;Han, Hee Dong;Kim, Hyuk Soon;Choi, Wahn Soo;Park, Won Sun;Park, Yeong-Min;Jung, In Duk
    • BMB Reports
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    • 제50권5호
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    • pp.263-268
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    • 2017
  • ${\beta}$-Agarase cleaves the ${\beta}$-1,4 linkages of agar to produce neoagarooligosaccharides (NAO), which are associated with various physiological functions. However, the immunological functions of NAO are still unclear. In this study, we demonstrated that ${\beta}$-agarase DagA-produced neoagarohexaose (DP6), an NAO product, promoted the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4). DP6 directly and indirectly enhanced the activation of natural killer (NK) cells in a TLR4-dependent manner in vitro and in vivo. Finally, the antitumor activity of DP6 against B16F1 melanoma cells was inhibited in NK cell-depletion systems by using NK-cell depleting antibodies in vivo. Collectively, the results indicated that DP6 augments antitumor immunity against B16F1 melanoma cells via the activation of DC-mediated NK cells in a TLR4-dependent manner. Thus, DP6 is a potential candidate adjuvant that acts as an immune cell modulator for the treatment of melanoma.

In Vitro Neural Cell Differentiation Derived from Human Embryonic Stem Cells: I. Effect of Neurotrophic Factors on Neural Progenitor Cells

  • Kim Eun-Yeong;Jo Hyeon-Jeong;Choe Gyeong-Hui;An So-Yeon;Jeong Gil-Saeng;Park Se-Pil;Im Jin-Ho
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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    • pp.18-18
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    • 2002
  • This study was to investigate the effect of neurotrophic factors on neural cell differentiation in vitro derived from human embryonic stem (hES, MB03) cells. For neural progenitor cell formation derived from hES cells, we produced embryoid bodies (EB: for 5 days, without mitogen) from hES cells and then neurospheres (for 7 - 10 days, 20 ng/㎖ of bFGF added N2 medium) from EB. And then finally for the differentiation into mature neuron cells, neural progenitor cells were cultured in ⅰ) N2 medium (without bFGF), ⅱ) N2 supplemented with brain derived neurotrophic factor (BDNF, 5ng/㎖) or ⅲ) N2 supplemented with platelet derived growth factor-bb (PDGF-bb, 20ng/㎖) for 2 weeks. (omitted)

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Odontogenic Ameloblast-Associated Protein (Odam) Plays Crucial Roles in Osteoclast Differentiation via Control of Actin Ring Formation

  • Lee, Hye-Kyung;Park, Joo-Cheol
    • Journal of Korean Dental Science
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    • 제8권2호
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    • pp.74-81
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    • 2015
  • Purpose: In osteoclast differentiation, actin-rich membrane protrusions play a crucial role in cell adhesion. Odontogenic ameloblast-associated protein (Odam) contributes to cell adhesion by inducing actin rearrangement. Odam-mediated RhoA activity may play a significant role in multinucleation of osteoclasts. However, the precise function of Odam in osteoclast cell adhesion and differentiation remains largely unknown. Here, we identify a critical role for Odam in inducing osteoclast adhesion and differentiation. Materials and Methods: The expression of Odam in osteoclasts was evaluated by immunohistochemistry. Primary mouse bone marrow and RAW264.7 cells were used to test the cell adhesion and actin ring formation induced by Odam. Result: Odam was expressed in osteoclasts around alveolar bone. Odam transfection induced actin filament rearrangement and cell adhesion compared with the control or collagen groups. Overexpression of Odam promoted actin stress fiber remodeling and cell adhesion, resulting in increased osteoclast fusion. Conclusion: These results suggest that Odam expression in primary mouse osteoclasts and RAW264.7 cells promotes their adhesion, resulting in the induction of osteoclast differentiation.

생체재료의 선택에 따른 조골세포의 형상, 증식 및 분화 (Osteoblast Cell Morphology, Proliferation, and Differentiation in Variation with Biomaterials)

  • 김학관;장주웅;정희석;이득용
    • 한국세라믹학회지
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    • 제40권6호
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    • pp.601-607
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    • 2003
  • 재료의 선택에 따른 생체친화성을 고찰하기 위해서 조골세포의 세포배양실험을 실시하였으며, 이로부터 세포의 부착형상, 증식, 분화의 정도를 살펴보았다. 본 실험에서 세포배양모재는 체내식립재료로 주목을 받고 있는 TiO$_2$, 3Y-TZP, HA (Hydroxyapatite) 그리고 Ti를 사용하였으며 대조군으로 Thermanox를 선택하였다. 일반적으로 모든 시편들은 같은 세포배양시간일때 거의 유사한 세포부착형상을 보였다. 그러나, HA위의 세포들은 나머지 시편들보다 좀 더 두꺼운 형상을 보였으며 빠른 세포의 부착 및 퍼짐으로 인한 overlapping이 자주 관찰되었다. 세포의 증식 및 분화의 경우에도 생체활성의 특성을 지니는 HA가 가장 높은 값을 보였으며 생체불활성재료인 경우에는 Ti, TiO$_2$, 3Y-TZP모두 유의한 차이를 보이지 않고 비슷한 경향을 나타내었다.

Mesenchymal stem cells and osteogenesis

  • Jung, Cho-Rok;Kiran, Kondabagil R.;Kwon, Byoung S.
    • IMMUNE NETWORK
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    • 제1권3호
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    • pp.179-186
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    • 2001
  • Bone marrow stroma is a complex tissue encompassing a number of cell types and supports hematopiesis, differentiation of erythreid, nyel and lymphoid lineages, and also maintains undifferentiated hematopoietic stem cells. Marrow-derived stem cells were composed of two populations, namely, hematopoietic stem cells that can differentiate into blood elements and mesenchymal stem cells that can give rise to connective tissues such as bone, cartilage, muscle, tendon, adipose and stroma. Differentiation requires environmental factors and unique intracellular signaling. For example, $TGF-{\beta}$ or BMP2 induces osteoblastic differentiation of mesenchymal stem are very exciting. However, the intrinsic controls involved in differentiation of stem cells are yet to be understood properly in order to exploit the same. This review presents an overview of the recent developments made in mesenchymal stem cell research with respect to osteogenesis.

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