• Journal of Life Science
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• v.34 no.4
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• pp.271-278
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• 2024

Redox factor (Ref)-1, a ubiquitously expressed protein, acts as a modulator of redox-sensitive tran- scription factors and as an endonuclease in the repair pathway of damaged DNA. However, the function of Ref-1 in the differentiation of monocytes into macrophages has not been defined. In this study, we investigated the effects of Ref-1 on the monocyte differentiation process using the human monocytic cell line THP-1. The differentiation agent PMA increased cell adhesion over time and showed a sig- nificant increase in phagocytic function but decreased the intracellular amount of Ref-1. Ref-1 inhibitor E3330 and Ref-1 knockdown using the siRNA technique reduced cell adhesion and the expression of differentiation markers, such as CD14, ICAM-1, and CD11b, by PMA stimulation. This means that the role of Ref-1 is absolutely necessary in the initial process of differentiating THP-1 cells stimulated by PMA. Next, the distribution of Ref-1 was examined in the cytoplasm and nucleus of THP-1 cells stimulated with PMA. Surprisingly, PMA stimulation resulted in the rapid translocation of Ref-1 to the nucleus. To prove that movement of Ref-1 to the nucleus is required for monocyte differentiation, a Ref-1 vector with the nuclear localization sequence (NLS) deleted was used. As a result, overexpression of ∆NLS Ref-1, which restricted movement to the nucleus, suppressed the expression of differentiation markers and notably reduced phagocytic function in PMA-stimulated THP-1 cells. In conclusion, these data suggest that the differentiation of monocytic THP-1 cells requires Ref-1 nuclear translocation during the initial process of biochemical events following stimulation from PMA.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.83-87
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• 2000

To investigate the effect of growth regulators and antioxidant in anther floating cultures of rice, anthers were cultured in liquid media supplemented with different growth regulators, and the effect of antioxidant mixture : (Sigma Chemical Co.) on callus induction and plant regeneration were investigated. N6 medium with 1 mg/L 2,4-D and 1 mg/L kinetin was the best for rice anther floating cultures, which showed 48.5% of callus induction and 6.8% of green plant regeneration. The callus induction was not affected by antioxidant mixture in liquid medium, and antioxidant mixture (250 mg/L) was effective for the reduction of brownish callus and improvement of plant regeneration Antioxidant mixture showed better effectiveness when it was supplemented to both media for callus induction and plant regeneration.

• Animal Systematics, Evolution and Diversity
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• v.6 no.1
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• pp.17-28
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• 1990

Electrophoretic methods were used to examine the degree of genic variation and genetic relatedness in 11 populations representing 6 species and subspecies of the genus Parus in Korea. The average degree of genic variation of 3 subspecies of P. major was =1.2, =24.4% , D=0.042, and G=0.058, whereas the rest of the species showed slightly lower degree of genic variation than P. major. Genetic relatedness between subspecies and species in the genus Parus showed similar to those reported at comparable taxnonomic levels in other birds. But it appears to be considerably less than that of non avian taxa. Genetic relatedness between 3 subspecies of P.major and P. varius varius was closely related(=0.80), whereas between P.palustrius hellmayri and P.ater amurensis was relatively remote (=0.67). The presumed divergent times of P.palustrius hellmayri, P, ater amurensis , and P. varius varius were about 1.8, 1.6, and 1.0million years before present respectively, and 3 subspecies of P. major were recently differentiated about 100 thousands years before present.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1207-1213
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• 2006

Tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ has been implicated in skeletal diseases by promoting bone loss in inflammatory bone diseases. In the present study, we examined the effects of $TNF-{\alpha}$ on osteoblastic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). $TNF-{\alpha}$ dose-dependently promoted matrix mineralization of hBMSCs with a maximal stimulation at 2ng/ml. $TNF-{\alpha}$ increased expression of alkaline phosphatase, which plays a crucial role for the matrix deposition. The $TNF-{\alpha}-stimulated$ osteoblastic differentiation was not affected by $NF_kB$ inhibitors, BAY and SN50. However, a JNK-specific inhibitor, SP600125 completely abolished the $TNF-{\alpha}-stimulated$ matrix mineralization and expression of alkaline phosphatase. These results suggest that $TNF-{\alpha}$ enhances osteoblastic differentiation of hBMSCs through JNK-dependent pathway.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.503-514
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• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.69-76
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• 1994

Callus growth and shoot regeneration of Solanum and Lycopersicon depended on genotype, growth regulators, and thiamine concentration. L. peruvianum LA 1277 and L. peruvianum LA 1373 and PI 251301 had the greatest callus growth while L hirsutum LA 1777, L.esculentum 'Diego'and 'Red Plum' had the least callus growth. Lycopersicon penvianum genotypes were superior to L. esculentur genotypes in regenerating plants. MG medium was more effective in regenerating shoots than MS medium. A low level of IAA (0.2mg/L) and high level of BA (2 mg/L) resulted in the greatest shoot regeneration. Shoot growth varied depending on thiamine concentration and genotype. Shoot proliferation of Solanum ptycathum, Solanum nigrum, and L. peruvianum PI 199380 was best on medium with 20 mg/L thiamine. Regeneration of L. peruvianum PI 251301 and PI 128652 was better on medium with 30 and 10mg/L thiamine, respectively.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.145-150
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• 2001

Reactivation of human cytomegalovirus (HCMV) from latency is often fatal to immunocompromised individuals. To understand the effect of HCMV on human monocytes where HCMV establishes latency, two human monocyte cell lines at different stages in differentiation, THP-1 and HL-60 were infected with HCMV. While the viability and morphology of HL-60 cells were not significantly affected by HCMV, the viability of THP-1 cells was dramatically decreased by HCMV infection. THP-1 cells infected with HCMV became aggregated and adhered to the surface of culture dishes, probably due to the increased expression of adherence molecules CD11b on the infected THP-1 cells. THP-1 cells established a latent HCMV infection were induced to differentiate by treatment with TPA and hydrocortisone. Recovery of infectious HCMV from the culture supernatant of differentiated THP-1 cells was dependent on the time of induction of differentiation after HCMV infection. Thus, in vitro model of reactivation of HCMV from latently infected monocytes was established.

• Journal of Life Science
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• v.28 no.9
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• pp.999-1006
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• 2018

Obesity is epidemic worldwide and has reportedly been linked to the progression of several metabolic and cardiovascular diseases. The natural products are decreasing the side effects of medicines used for obesity and also have health benefits dut to their numerous bioactive compounds. In this context, Artemisia scoparia is a widespread plant that has been suggested as possessing various types of bioactivity. In this study, the crude extract from A. scoparia (ASE) was tested for its ability to suppress adipogenesis in mouse 3T3-L1 pre-adipocytes. The molecular pathway by which ASE affects differentiation of 3T3-L1 cells was also investigated. The introduction of ASE to differentiating 3T3-L1 pre-adipocytes resulted in suppressed adipogenesis, as confirmed by decreased intracellular lipid accumulation. The differentiating cells treated with 10 and $100{\mu}g/ml$ of ASE showed 21.9 and 29.0% less lipid accumulation, respectively, than untreated adipocytes. In addition, the results indicated that ASE treatment lowered the expression of the adipogenesis-related factors $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP-1c. Furthermore, treating with ASE notably decreased levels of phosphorylated p38, ERK, and JNK in 3T3-L1 adipocytes. These results indicate that ASE exhibits significant anti-adipogenesis activity by downregulating the MAPK and $PPAR{\gamma}$ pathways during the differentiation of 3T3-L1 pre-adipocytes. Therefore, A. scoparia may be a potential source of natural products against obesity.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.350-357
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• 2017

The purpose of this study was to evaluate the difference of differentiation potential in each passage of dental pulp stem cells from supernumerary tooth (sDPSCs). The sDPSCs were obtained from a healthy 6-year-old male patient under the guidelines and got the informed consent. Cells were cultured until passage number 16 and divided into two groups; 1 - 8 passages as a young group and 9 - 16 passages as an old group. It was taken $2.25{\pm}0.46days$ in a young group and $3.25{\pm}0.46days$ in an old group to propagate cells of each passage until confluence and there were statistically significant differences between two groups (p < 0.05). In every passage, cell morphology was observed with microscope and evaluated the capacity to form high levels of minerals by alizarin red solution staining after treating differentiation medium. Fibroblast-like, spindle shaped, elongated cells and a few nodules were found in uninduced cultures of passage number 1, 8 and 9. But at 16 passage culture, cell size became larger and broader and observed with more nodules. After inducing differentiation, mineralized nodules were detected at the first passage of 7th day culture whereas at the 8 passage culture, nodules were seen clearly at 14th day culture. In addition, the amount of mineralized nodules were remarkably decreased after passage 9. From the data presented in this study, it is recommended to use sDPSCs of passage number within 8 for utilizing as stem cells.

• Journal of Life Science
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• v.33 no.6
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• pp.512-522
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• 2023

Cancer with unlimited cell growth is a leading cause of death globally. Various cancer treatments, including surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy, can be applied alone or in combination depending on the cancer type and stage. New treatments with fewer side effects than previous cancer treatments are continually under development and in demand. Undifferentiated stem cells with unlimited cell growth are gradually changed via cellular differentiation to arrest cell growth. In this study, we reviewed the possibility of treating cancer by using cellular differentiation into the adipocytes in cancer cells. In previous in vitro studies, oral antidiabetic drugs of the thiazolidinedione (TDZ) class, such as rosiglitazone and pioglitazone, were induced into the adipocytes in various cancer cell lines via increased peroxisome proliferator-activated receptor-γ (PPAR γ) expression and glucose uptake, which is the key regulator of adipogenesis and the energy metabolism pathway. The differentiated adipogenic cancer cells treated with TDZ inhibited cell growth and had a less cellulotoxic effect. This adipogenic differentiation treatment suggests a possible chemotherapy option in cancer cells with high and abnormal glucose metabolism levels. However, the effects of the in vivo adipogenic differentiation treatment need to be thoroughly investigated in different types of stem and normal cells with other side effects.