• The Plant Pathology Journal
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• v.17 no.2
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• pp.88-93
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• 2001

Oxidative stress is one of the major limiting factor in plant productivity. Reactive oxygens species (ROS) generated during metabolic processes damage cellular functions and consequently lead to disease, senescence and cell death. Plants have evolved an efficient defense system by which the ROS is scavenged by antioxidant enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). Attempts to reduce oxidative damages under the stress conditions have included the manipulation of 갠 scavenging enzymes by gene transfer technology. Increased SOD activities of transgenic plants lead to increased resistance against oxidative stresses derived from methyl viologen (MV), and from photooxidative damage caused by high light and low temperature. Transgenic tobacco plants overexpressing APX showed reduced damage following either MV treatment of photooxidative treatment. Overexpression of glutathion reductase (GR) leads to increase in pool of ascorbate and GSH, known as small antioxidant molecules. These results indicate through overexpression of enzymes involved in ROS-scavenging could maintain or improve the plant productivities under environment stress condition. In this study, the rational approaches to develop stress-tolerant plants by gene manipulation of antioxidant enzymes will be introduced to provide solutions for the global food and environmental problems in the $21^\textrm{st}$ century.

• Biomedical Science Letters
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• v.10 no.2
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• pp.85-92
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• 2004

Immortalization of primary corneal cells has influence on pharmacy, medical and biological fields. Especially, investigation of immortalization mechanism using viral oncoproteins is useful for medical treatments, and these cell lines will be useful materials for toxic test of medical supplies and cell biological experiments. Rabbit corneal fibroblasts in culture undergo a finite number of divisions before they reach a terminally non-proliferating state known as replicative senescence. Therefore, we attempted to induce immortalization of rabbit corneal fibroblasts with SV 40 large T antigen. As a result of experiment, expression of SV 40 large T antigen was confirmed, and expression of proteins related to cell cycle repressor was decreased in the transfection group compared with non-transfection group. According to the results of cell cycle phase distribution test, SV 40 large T antigen-transfected cells had obtained higher proliferation rate than primary cells. It was confirmed that during induction of immortalization, SV 40 large T antigen was not able to increase telomerase activity. In conclusion, we made a rabbit corneal fibroblast cell line with SV40 large T antigen. This cell line will be useful for further studies of mammalian fibroblast biology, particularly with regard to angiogenesis and malignant transformation. In addition, this cell line offers opportunity for testing potential therapeutics and can be used for toxicity tests of materials or cosmetics. In the future, our cell line can potentially be utilized in a wide range of biology related fields.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.382-393
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• 2023

Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.68-76
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• 2024

Background: Although the survival outcomes of childhood cancer patients have improved, childhood cancer survivors suffer from various degrees of immune dysfunction or delayed immune reconstitution. This study aimed to investigate the effect of Korean Red Ginseng (KRG) on T cell recovery in childhood cancer patients who underwent autologous hematopoietic stem cell transplantation (ASCT) from the perspective of inflammatory and senescent phenotypes. Methods: This was a single-arm exploratory trial. The KRG group (n = 15) received KRG powder from month 1 to month 12 post-ASCT. We compared the results of the KRG group with those of the control group (n = 23). The proportions of T cell populations, senescent phenotypes, and cytokine production profiles were analyzed at 1, 3, 6, and 12 months post-ASCT using peripheral blood samples. Results: All patients in the KRG group completed the treatment without any safety issues and showed a comparable T cell repopulation pattern to that in the control group. In particular, KRG administration influenced the repopulation of CD4⁺ T cells via T cell expansion and differentiation into effector memory cell re-expressing CD45RA (EMRA) cells. Although the KRG group showed an increase in the number of CD4⁺ EMRA cells, the expression of senescent and exhausted markers in these cells decreased, and the capacity for senescence-related cytokine production in the senescent CD28^- subset was ameliorated. Conclusions: These findings suggest that KRG promotes the repopulation of CD4⁺ EMRA T cells and regulates phenotypical and functional senescent changes after ASCT in pediatric patients with cancer.

• Preventive Nutrition and Food Science
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• v.19 no.3
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• pp.129-135
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• 2014

The protective role of phloroglucinol against oxidative stress and stress-induced premature senescence (SIPS) was investigated in vitro and in cell culture. Phloroglucinol had strong and concentration-dependent radical scavenging effects against nitric oxide (NO), superoxide anions ($O_2{^-}$), and hydroxyl radicals. In this study, free radical generators were used to induce oxidative stress in LLC-PK1 renal epithelial cells. Treatment with phloroglucinol attenuated the oxidative stress induced by peroxyl radicals, NO, $O_2{^-}$, and peroxynitrite. Phloroglucinol also increased cell viability and decreased lipid peroxidation in a concentration-dependent manner. WI-38 human diploid fibroblast cells were used to investigate the protective effect of phloroglucinol against hydrogen peroxide ($H_2O_2$)-induced SIPS. Phloroglucinol treatment attenuated $H_2O_2$-induced SIPS by increasing cell viability and inhibited lipid peroxidation, suggesting that treatment with phloroglucinol should delay the aging process. The present study supports the promising role of phloroglucinol as an antioxidative agent against free radical-induced oxidative stress and SIPS.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.188-195
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• 2000

Using Ginseng saponins (crude saponin and total saponin) and ginsenoside Rbl Rb2, Rc, Rd, Re, Rhl, and Rh2 in this study, we have examined the effects of the compounds on the induction of differentiation in normal rat mammary epithelial cells and 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumor cells in culture. When normal rat mammary organoids were cultured in 100-mm culture plates in the presence or absence of ginseng saponins, there were four different cell colonies after two weeks in culture: cobble stone, spindle, honey comb, and senescence type colonies. Ginseng saponins showed different effects on the development of each colonies. Scrape-loading dye transfer tech-nique was performed to measure the effects of total saponin, Rhl, and Rh2 on intercellular junctional communication. Intercellular communication was not observed at short cultilral time, e.g., four or seven days, but when it cultured it up to two weeks, cell to cell communication was observed in saponin-treated cells. Reconstituted basement membrane, Matrigel, supported the growth and development several different multicellular structures from normal mammary organoids (e.g., ductal, webbed, stellate, and squamous colonies) or DMBA-induced mammary tumor (e.g., alveolar unit, foamy alveolar unit, squamous metaplasia, lobule-ductal, stellate, and webbed colony). In ginseng saponin-treated groups, webbed colonies were more and squamous colonies were less than control group. Moreover, the ductal colonies, marker tructure of well-differentiate mammary epithelial cells, were developed more in saponin-treated group than in control group. In conclusion, ginseng saponins affected on the differentiation of normal rat mammary epithelial cells and DMBA-induced mammary tumor cells in culture.

• Molecules and Cells
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• v.38 no.12
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• pp.1096-1104
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• 2015

Particulate $matter_{2.5}$ ($PM_{2.5}$) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which $PM_{2.5}$ aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous $PM_{2.5}$ solution on lipoprotein metabolism. Collected $PM_{2.5}$ from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. $PM_{2.5}$ extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. $PM_{2.5}$ treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by $PM_{2.5}$ solution in a dose-dependent manner. Further, $PM_{2.5}$ solution caused cellular senescence in human dermal fibroblast cells. Microinjection of $PM_{2.5}$ solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of $PM_{2.5}$ induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins.

• Molecules and Cells
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• v.21 no.1
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• pp.147-152
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• 2006

Most plant organs develop from meristems. Rice FON1, which is an ortholog of Clv1, regulates stem cell proliferation and organ initiation. The point mutations, fon1-1 and fon1-2, disrupt meristem balance, resulting in alteration of floral organ numbers and the architecture of primary rachis branches. In this study, we identified two knockout alleles, fon1-3 and fon1-4, generated by T-DNA and Tos17 insertion, respectively. Unlike the previously isolated point mutants, the null mutants have alterations not only of the reproductive organs but also of vegetative tissues, producing fewer tillers and secondary rachis branches. The mutant plants are semi-dwarfs due to delayed leaf emergence, and leaf senescence is delayed. SEM analysis showed that the shoot apical meristems of fon1-3 mutants are enlarged. These results indicate that FON1 controls vegetative as well as reproductive development by regulating meristem size.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.313-322
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• 2013

Ultraviolet irradiation in the cells and skin produces reactive oxygen species (ROS), which induces the synthesis of matrix metalloproteinases (MMPs) causing skin photoaging. Using the human dermal fibroblast (HDF), we investigated the antioxidative and anti-aging effects of the extracts from Talinum paniculatum. Talinum paniculatum leaf and stem extracts (LSE) showed free radical scavenging effect by 98.45% at 500 ${\mu}g/mL$ and superoxide radical scavenging effect by 97.01% at 500 ${\mu}g/mL$ in the xanthine/xanthine oxidase system. The photoprotective potential of LSE was tested in HDF exposed to ultraviolet irradiation. It was revealed that LSE had an inhibitory effect on MMP-1 expression in UVA-irradiated HDF without any significant cytotoxicity. The treatment of UVA-irradiated HDF with LSE resulted in dose-dependent decreases in the expression levels of MMP-1 mRNA and protein. Also, UVB-induced cytotoxicity and cell death were effectively suppressed by treatment of LSE. Additionally, the senescence-associated ${\beta}$- galactosidase (SA-${\beta}$-gal) activity was decreased in the presence of LSE. These results suggest that Talinum paniculatum leaf and stem extracts (LSE) may have anti-aging effects and can be used as new functional materials against oxidative stress-mediated skin damages.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.623-634
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• 2005

Human periodontal ligament fibroblast(hPDLF) is very important to cure periodontal tissue because it can be diverged into various cells. This study examined the expression of MMP-1, TIMP-1, periodontal ligament specific PDLs22, Type I collagen, Fibronectin, TIMP-2, telomerase mRNA in a replicative senescence of hPDLF. The periodontal ligament tissue was obtained from periodontally healthy and non-carious human teeth extracted for orthodontic reasons at the Chosun University Hospital of Dentistry with the donors' informed consent. The hPDLF cells were cultured in a medium containing Dulbecco's modified Eagle medium(DMEM, Gibco BRL, USA) supplemented with 10% fetal bovine serum(FBS, Gibco BRL, USA) at 37C in humidified air with 5% $CO_2$. For the reverse transcription-polymerase chain reaction(RT-PCR) analysis, the total RNA of the 2, 4, 8, 16, 18, and 21 passage cells was extracted using a Trizol Reagent(Invitrogen, USA) in replicative hPDL cells. Two passage cells, i.e. young cells, served as the control, and ${\beta}-actin$ served as the internal control for RT-PCR The results of this study about cell morphology and gene expression according to aging of hPDLF using RT-PCR method are as follows: 1. The size of hPDLF was increased with aging and it was showed that the hPDLF was dying in the final passage. 2. PDLs22 mRNA was expressed in young hPDLF of the two, four, and six passage. 3. TIMP-1 mRNA was expressed in young hPDLF of the two and four passage. 4. There was a tendency that MMP-1 mRNA was weakly expressed over eighteen. 5. Type 1 collagen mRNA was expressed in almost all passages, but it was not expressed in the final passage. 6. Fibronectin mRNA was observed in all passages and it was weakly expressed in the final passage. 7. TIMP-2 and telomerase mRNA were not expressed in this study. Based on above results, it was observed that PDLs22, Type 1 collagen, Fibronectin, MMP-1. and TIMP-1 mRNA in hPDLF were expressed differently with aging. The study using the hPDLF that is collected from healthy patients and periodontitis patients needs in further study.