• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.498-505
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• 2009

The plant Agastache rugosa Kuntze has various physiological and pharmacological activities. Especially, it has been regarded as a valuable source for the treatment of anti-inflammatory and oxidative stress-induced disorders. However, little has been known about the functional role of it on oxidative damage in mammalian cells by ROS. In this study, we investigated the DPPH radical, hydroxyl radical, hydrogen peroxide and intracellular ROS scavenging capacity, and $Fe^{2+}$ chelating activity of the extracts from Agastache rugosa. In addition, we evaluated whether the extract can be capable of reducing $H_2O_2$-induced DNA and cell damage in NIH 3T3 cells. These extracts showed a dose-dependent free radical scavenging capacity and a protective effect on DNA damage and the lipid peroxidation causing the cell damage by $H_2O_2$. Therefore, these results suggest that Agastache rugosa is useful as a herbal medicine for the chemoprevention against oxidative carcinogenesis.

• BMB Reports
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• v.43 no.10
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• pp.683-687
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• 2010

Previous studies have shown that one of the primary causes of increased iron content in the brain may be the release of excess iron from intracellular iron storage molecules such as ferritin. Free iron generates ROS that cause oxidative cell damage. Carnosine and related compounds such as endogenous histidine dipetides have antioxidant activities. We have investigated the protective effects of carnosine and homocarnosine against oxidative damage of DNA induced by reaction of ferritin with $H_2O_2$. The results show that carnosine and homocarnosine prevented ferritin/$H_2O_2$-mediated DNA strand breakage. These compounds effectively inhibited ferritin/$H_2O_2$-mediated hydroxyl radical generation and decreased the mutagenicity of DNA induced by the ferritin/$H_2O_2$ reaction. Our results suggest that carnosine and related compounds might have antioxidant effects on DNA under pathophysiological conditions leading to degenerative damage such as neurodegenerative disorders.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.282.1-282.1
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• 2002

Paeoniae radix is commonly used for various woman's health problems in traditional korean medicine. In order to develop new antioxidant for woman use. the ethanolic extracts of paeoniae radix (PRE) were prepared and various biological activities were evaluated. PRE showed potent free radical scavenging activity and moderate antioxidative activity in vitro. and also showed the protective effect on H2O2-induced DNA damage in mammalian cell. (omitted)

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.164-169
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• 1995

An endogenous cryptic plasmid, pBL1, which has been used to construct plasmid vectors for coryneform bacteria producing amino acids, was eliminated from Brevibacterium lactofermentum. The pBL1 was partially digested with Sau3AI and the resulting DNA fragments were subcloned into a suicide vector pEM1 which contains a kanamycin-resistant (km$^{r}$) gene. KM$^{r}$ B. lactofermentum transconjugants were obtained by conjugal transfer of the pEM1 derivatives containing pBL1 DNA fragments from Escherichia coli into B. lactofermentum. A km$^{r}$ transconjugant was analyzed to contain a plasmid pEB14, which occurred in vivo by homologous recombination between pBL1 and the conjugal-transferred plasmid. The pEB14 including the pEM1-derived km$^{r}$ gene was found to be lost concomitantly with km$^{r}$ phenotype, resulting in the construction of a pBL1-free strain of B lactofermentum. Based on transformation efficiencies and plasmid stability, the resultant pBL1- free strain is more useful than wild strain as a host cell for genetic manipulation. It could be concluded that foreign plasmid DNAs are efficiently isolated and analyzed from the pBL1-free strain because of the absence of endogenous pBL1 plasmid.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.94-94
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• 2003

Endocrine disrupters (EDs) are exogenous chemicals that interfere with the production, releasing, metabolism, excretion, binding of natural hormones, and whole endocrine systems. EDs are very dangerous since they are extremely stable, not easily degraded, and accumulated in fat and tissue. 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is known as the most toxic EDs. Therefore, this study was conducted to investigate the effects of TCDD on proliferation of human breast cancer (MCF-7) and endometrial adenocarcinoma (Hec-1B) cells. 10, 100, and 1000 nM of TCDD were treated with steroid free condition. Viable cell counting, MTT, and BrdU assay was performed to investigate cell proliferation. Apoptosis was investigated using DNA laddering. Although, DNA fragmentation as the evidence of apoptosis was not detected, all of these cell lines showed restricted proliferation at 48 hrs after 100 and 1000 nM TCDD treatments. Recently, it has been reported that the expression of transforming growth factor $\beta$s (TGF-$\beta$s) are increased in TCDD treatment and also involved in regulation of cell cycle. Therefore, these results were considered that the decreased cell prolifcration by TCDD is related to the expression of TGF-$\beta$s.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.501-505
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• 2021

The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri-induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.

• Molecules and Cells
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• v.40 no.2
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• pp.83-89
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• 2017

Error-free replication and repair of DNA are pivotal to organisms for faithful transmission of their genetic information. Cells orchestrate complex signaling networks that sense and resolve DNA damage. Post-translational protein modifications by ubiquitin and ubiquitin-like proteins, including SUMO and NEDD8, are critically involved in DNA damage response (DDR) and DNA damage tolerance (DDT). The expression of interferon-stimulated gene 15 (ISG15), the first identified ubiquitin-like protein, has recently been shown to be induced under various DNA damage conditions, such as exposure to UV, camptothecin, and doxorubicin. Here we overview the recent findings on the role of ISG15 and its conjugation to target proteins (e.g., p53,$ {\Delta}Np63{\alpha}$, and PCNA) in the control of cellular responses to genotoxic stress, such as the inhibition of cell growth and tumorigenesis.

• Genomics & Informatics
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• v.15 no.1
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• pp.2-10
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• 2017

Early detection and proper management of kidney rejection are crucial for the long-term health of a transplant recipient. Recipients are normally monitored by serum creatinine measurement and sometimes with graft biopsies. Donor-derived cell-free deoxyribonucleic acid (cfDNA) in the recipient's plasma and/or urine may be a better indicator of acute rejection. We evaluated digital PCR (dPCR) as a system for monitoring graft status using single nucleotide polymorphism (SNP)-based detection of donor DNA in plasma or urine. We compared the detection abilities of the QX200, RainDrop, and QuantStudio 3D dPCR systems. The QX200 was the most accurate and sensitive. Plasma and/or urine samples were isolated from 34 kidney recipients at multiple time points after transplantation, and analyzed by dPCR using the QX200. We found that donor DNA was almost undetectable in plasma DNA samples, whereas a high percentage of donor DNA was measured in urine DNA samples, indicating that urine is a good source of cfDNA for patient monitoring. We found that at least 24% of the highly polymorphic SNPs used to identify individuals could also identify donor cfDNA in transplant patient samples. Our results further showed that autosomal, sex-specific, and mitochondrial SNPs were suitable markers for identifying donor cfDNA. Finally, we found that donor-derived cfDNA measurement by dPCR was not sufficient to predict a patient's clinical condition. Our results indicate that donor-derived cfDNA is not an accurate predictor of kidney status in kidney transplant patients.

• Journal of Web Engineering
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• v.14 no.15
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• pp.3206-3218
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• 2022

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the gastric mucosa and triggers various stomach diseases. H. pylori induces reactive oxygen species (ROS) production and DNA damage. The heterodimeric Ku70/Ku80 protein plays an essential role in the repair of DNA double-strand breaks (DSB). Oxidative stress stimulate apoptosis and DNA damage that can be repaired by Ku70/80. However, excessive reactive oxygen species (ROS) can cause Ku protein degradation, resulting in DNA fragmentation and apoptosis. α-lipoic acid (α-LA), which is found in organ meats such as liver and heart, spinach, broccoli, and potatoes, quenches free radicals, chelates metal ions, and reduces intracellular DNA damage induced by oxidative stress. Here, we investigated whether H. pylori decreases Ku70/80 and induces apoptosis, and whether α-LA inhibits changes induced by H. pylori. We analyzed ROS, DNA damage markers (γ-H2AX, DNA fragmentation), levels of Ku70/80, Ku-DNA binding activity, Ku80 ubiquitination, apoptosis indices (Bcl-2, Bax, apoptosis-inducing factor (AIF), and caspase-3), and viability in a human gastric epithelial adenocarcinoma cell line (AGS). H. pylori increased ROS, DNA damage markers, Ku80 ubiquitination, and consequently induced apoptosis. It also decreased nuclear Ku70/80 levels and Ku-DNA-binding activity; increased Bax expression, caspase-3 cleavage, and truncated AIF; but decreased Bcl-2 expression. These H. pylori-induced alterations were inhibited by α-LA. The antioxidant N-acetylcysteine and proteasome inhibitor MG-132 suppressed H. pylori-induced cell death and decreased nuclear Ku70/80 levels. The results show that oxidative stress induced Ku70/80 degradation via the ubiquitin-proteasome system, leading to its nuclear loss and apoptosis in H. pylori-infected cells. In conclusion, α-LA inhibited apoptosis induced by H. pylori by reducing ROS levels and suppressing the loss of Ku70/80 proteins in AGS cells.

• BMB Reports
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• v.52 no.12
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• pp.689-694
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• 2019

Ethical and safety issues have rendered mesenchymal stem cells (MSCs) popular candidates in regenerative medicine, but their therapeutic capacity is lower than that of induced pluripotent stem cells (iPSCs). This study compared original, dental tissue-derived MSCs with re-differentiated MSCs from iPSCs (iPS-MSCs). CD marker expression in iPS-MSCs was similar to original MSCs. iPS-MSCs expressed higher in pluripotent genes, but lower levels in mesodermal genes than MSCs. In addition, iPS-MSCs did not form teratomas. All iPSCs carried mtDNA mutations; some shared with original MSCs and others not previously detected therein. Shared mutations were synonymous, while novel mutations were non-synonymous or located on RNA-encoding genes. iPS-MSCs also harbored mtDNA mutations transmitted from iPSCs. Selected iPS-MSCs displayed lower mitochondrial respiration than original MSCs. In conclusion, screening for mtDNA mutations in iPSC lines for iPS-MSCs can identify mutation-free cell lines for therapeutic applications.