• BMB Reports
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• 제48권7호
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• pp.369-370
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• 2015

Actin dynamics is critical for the formation and sustainment of the immunological synapse (IS) during T cell interaction with antigen-presenting cells (APC). Thus, many actin regulating proteins are involved in spatial and temporal actin remodeling at the IS. However, little is known whether or how actin stabilizing protein controls IS and the consequent T cell functions. TAGLN2 − an actin-binding protein predominantly expressed in T cells − displays a novel function to stabilize cortical F-actin, thereby augmenting F-actin contents at the IS, and acquiring leukocyte function-associated antigen-1 activation following T cell activation. TAGLN2 also competes with cofilin to protect F-actin in vitro and in vivo. During cytotoxic T cell interaction with cancer cells, the expression level of TAGLN2 at the IS correlates with the T cell adhesion to target cancer cells and production of lytic granules such as granzyme B and perforin, thus expressing cytotoxic T cell function. These findings identify a novel function for TAGLN2 as an actin stabilizing protein that is essential for stable immunological synapse formation, thereby regulating T cell immunity. [BMB Reports 2015; 48(7): 369-370]

• Molecules and Cells
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• 제22권1호
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• pp.113-118
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• 2006

Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

• International Journal of Oral Biology
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• 제45권4호
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• pp.197-203
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• 2020

Mesenchymal stem cells in the dental pulp exhibit a tendency for differentiation into various dental lineages and hold great potential as a major conduit for regenerative treatment in dentistry. Although they can be readily isolated from teeth, the exact characteristics of these stem cells have not been fully understood so far. When compared to two-dimensional (2D) cultures, three-dimensional (3D) cultures have the advantage of enriching the stem cell population. Hence, 3D-organoid culture and 3D-sphere culture were applied to dental pulp cells in the current study. Although the establishment of the organoid culture proved unsuccessful, the 3D-sphere culture readily initiated the stable generation of cell aggregates, which continued to grow and could be passaged to the second round. Interestingly, a significant increase in SOX2 expression was detected in the 3D-spheroid culture compared to the 2D culture. These results indicate the enrichment of the stemness-high population in the 3D-sphere culture. Thus, 3D-sphere culture may act as a link between the conventional and 3D-organoid cultures and aid in understanding the characteristics of dental pulp stem cells.

• 한국축산식품학회지
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• 제41권2호
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• pp.261-273
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• 2021

Leuconostoc mesenteroides H40 (H40) was isolated from kimchi, and its probiotic properties and neuroprotective effect was evaluated in oxidatively stressed SH-SY5Y cells. H40 was stable in artificial gastric conditions and can be attached in HT-29 cells. In addition, H40 did not produce β-glucuronidase and showed resistant to several antibiotics. The conditioned medium (CM) was made using HT-29 cells refined with heat-killed probiotics (Probiotics-CM) and heated yogurts (Y-CM) to investigate the neuroprotective effect. Treatment with H40-CM not only increased cell viability but also significantly improved brain derived neurotropic factor (BDNF) expression and reduced the Bax/Bcl-2 ratio in oxidatively stress-induced SH-SY5Y cells. Besides, probiotic Y-CM significantly increased BDNF mRNA expression and decreased Bax/Bcl-2 ratio. The physicochemical properties of probiotic yogurt with H40 was not significantly different from the control yogurt. The viable cell counts of lactic acid bacteria in control and probiotic yogurt with H40 was 8.66 Log CFU/mL and 8.96 Log CFU/mL, respectively. Therefore, these results indicate that H40 can be used as prophylactic functional dairy food having neuroprotective effects.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권2호
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• pp.84-91
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• 2000

Mycopasma contamination of tissue culture cells easily evades detection and, thus, represents a continous therat to cell biologists. In case where infected cell can not simply be replaced, attempts have to be made to eradicate mycoplacma from the tissue culture cells. A variety of anti-microbial agents have been shown to be toxic to mycoplasma strains ; however, cell associated mycoplasma are often protected from antibiotics at concentrations shown to be effective in vitro. Antibiotic concentrations high enough to be lethal to cell as sociated mycoplasmas frequently are also detrimentrations to the host cells, while moderately increased antibiotic levels tolerated by the host cells often lead to only temporary growth suppression and/or to the emergence of mycoplasma strains resistanct even to high concentrations of the antibiotis applied. Hare, a genetic approach for the elimination of mycoplasma from tissue culture cells that overcomes thens limitations is described. By expression of a selection marker conferring resistance to an otherwise toxic agent, Acholeplasma laidlawii infected BHK-21 cells used as the model system were enabled to temporarily tolerate antibiotic concentrations high enough to be lethal to cell associated mycopalsma while leaving the host cells unharmed. Upon successful mycoplasma eradicated, cultvation of the cured host cells in the absence of the selective agent yielded revertant cell clones that had regained susceptibillity to the toxic agent. Cressation of the selection marker expression was shown to result from the loss of the selection marker DNA, which is a consequence of the fact that the stable and permanent integration of foreign DNA in eucaryotic cell chrosomes is highly inefficient. Thus, the cells were cured from mycoplasma yet remained biochemically unaltered.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.370-378
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• 2009

N-myc downstream-regulated gene 2 (NDRG2) has recently been found to be a tumor suppressor gene. Although it has been reported that NDRG2 expression in breast cancer cells decreases cell proliferation by inhibiting STAT3 activation via SOCS1 induction, the molecular mechanism of chemotherapeutic agent-induced apoptosis is not well known. To elucidate the effect of NDRG2 on the apoptotic pathway induced by doxorubicin, we established stable cell lines expressing NDRG2 and investigated the effect of NDRG2 expression on the doxorubicin-induced apoptosis. While STAT3 activation was remarkably inhibited by NDRG2 overexpression, the expression level of p21 was increased by NDRG2 expression. We confirmed that NDRG2-expressing cells treated with doxorubicin suppressed STAT3 activation and upregulated p21 expression. NDRG2 expression considerably enhanced TUNEL positive apoptotic cells, poly-ADP ribose polymerase (PARP) cleavage, release of cytochrome c to cytosol, and caspase-3 activity in doxorubicin-induced apoptosis. Bid expression in a resting state and after treatment with doxorubicin increased in MDA-MB-231-NDRG2 cells compared to MDA-MB-231-mock cells. Meanwhile, Bcl-$x_L$ expression decreased in MDA-MB-231-NDRG2 cells compared to MDA-MB-231-mock cells in a resting state and in doxorubicin-treated cells. Collectively, these data suggest that suppression of STAT3 activation by NDRG2 influences the sensitivity to doxorubicin-induced apoptosis of breast cancer cells and this may provide a potential therapeutic benefit to overcome the resistance against doxorubicin in breast cancer.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권1호
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• pp.11-21
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• 2008

Aim of the study: Thermal stress is a central determinant of osseous surgical outcomes. Interestingly, the temperatures measured during endosseous surgeries coincide with the temperatures that elicit the heat shock response of mammalian cells. The heat shock response is a coordinated biochemical response that helps to protect cells from stresses of various forms. Several protective proteins, termed heat shock proteins (hsp) are produced as part of this response. To begin to understand the role of the stress response of osteoblasts during surgical manipulation of bone, the heat shock protein response was evaluated in osteoblastic cells. Materials & methods: With primary cell culture studies and ROS 17/2.8 osteoblastic cells transfected with hsp27 encoding vectors culture studies, the thermal stress response of mammalian osteoblastic cells was evaluated by immunohistochemistry and western blot analysis. Results: Immunocytochemistry indicated that hsp27 was present in unstressed osteoblastic cells, but not fibroblastic cells. Primarily cultured osteoblasts and fibroblasts expressed the major hsp in response to thermal stress, however, the small Mr hsp, hsp27 was shown to be a constitutive product only in osteoblasts. Creation of stable transformed osteoblastic cells expressing abundant hsp27 protein was used to demonstrate that hsp27 confers stress resistance to osteoblastic cells. Conclusions: The demonstrable presence and function of hsp27 in cultured bones and cells implicates this protein as a determinant of osteoblastic cell fate in vivo.

• 생명과학회지
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• 제17권9호통권89호
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• pp.1232-1236
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• 2007

인체 암세포계(MG-63 골육암 세포, HT-29 인체 결장암세포, K-562 백혈암세포)를 이용하여 느릅나무 근피 메탄올 추출물, 열탕 추출물 및 즙액에 의한 암세포 성장에 미치는 효과를 검토하였다. 느릅나무 근피 메탄올 추출물, 열탕 추출물 및 즙액은 낮은 농도에서부터 인체 골육암 세포의 증식을 억제시켰다. 인체 결장암세포와 백혈암세포에서도 느릅나무 근피 메탄올 추출물, 열탕 추출물 및 즙액은 낮은 농도인 1 mg/ml에서부터 활성을 나타내어 40% 이상으로 암세포 증식 억제효과를 나타내어 앞서의 MG-63 골육암 세포에서 보다 그 증식 억제효과가 높은 것으로 나타났다. 느릅나무 근피 메탄올 추출물, 열탕 추출물 및 즙액을 골육암과 결장암세포에 투여한 2일 후에 세포내의 DNA 합성에 미치는 영향을 측정한 결과, 농도 의존적으로 암세포의 DNA 합성을 저해하는 것을 살펴 볼 수가 있었다. 따라서 느릅나무 근피 추출물은 인체 암세포 증식을 크게 억제하였으며 열탕 추출물에서도 항암활성 효과를 보여 느릅나무 근피 유래 생리활성 물질은 열에 안정한 것으로 여겨진다.

• 미생물학회지
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• 제6권1호
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8631-8635
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• 2014

Glutathione S-transferase A1 (GSTA1) appears to be primarily involved in detoxification processes, but possible roles in lung cancer remain unclear. The objective of this study was to investigate the expression and function of GSTA1 in lung cancer cells. Real-time PCR and Western blotting were performed to assess expression in cancer cell lines and the normal lung cells, then verify the A549 cells line with stable overexpression. Localization of GSTA1 proteins was assessed by cytoimmunofluorescence. Three double-strand DNA oligoRNAs (SiRNAs) were synthesized prior to being transfected into A549 cells with Lipofectamine 2000, and then the most efficient SiRNA was selected. Expression of the GSTA1 gene in the transfected cells was determined by real-time PCR and Western blotting. The viability of the transfected cells were assessed by MTT. Results showed that the mRNA and protein expression of A549 cancer cells was higher than in MRC-5 normal cells. Cytoimmunofluorescence demonstrated GSTA1 localization in the cell cytoplasm and/or membranes. Transfection into A549 cells demonstrated that down-regulated expression could inhibit cell viability. Our data indicated that GSTA1 expression may be a target molecule in early diagnosis and treatment of lung cancer.