• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2863-2866
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• 2014

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.248-256
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• 1996

The present study was performed to clone and express human poly (ADP-ribose) synthetase (PARS) cDNA in E coli. For these purposes, the CDNA for human poly (ADP-ribose) synthetase, encoding the entire protein, was cloned into pGEM-7Zf(+). The resulting recombinant plasmid pPARS6.1 was restriction enzyme mapped and its identity was confirmed by Southern blot analysis. The pPARS6. 1 contained full-length CDNA of human PARS and the nudeotide sequences were identical with those reported previously. The recombinant protein which migrated as a unique 120 kDa band on 10% SDS-polyacrylamide gels, was identified as PARS by Southwestern blots using nick-translated DNA probes and by activity gels and activity blots using 32 P-NAD as a substrate for poly (ADP-ribose) synthetase (PARS). The signals corresponding to 120 and 98 kDa proteins were obtained following IPTG (0.4 mM) induction of the PARS cDNA cloned into Xba I-digested pGEM-7Zf(+) vector. Nonspecific signals corresponding to 45 and 38 kDa proteins were also shown in both IPTG-induced and noninduced cells. The nonspecific proteins may be products of incomplete translation or proteolytic products of intact PARS.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.79-91
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• 2021

γ-Glutamylcysteine synthetase (Gcs1) and glutathione reductase (Glr1) activity maintains minimal levels of cellular methylglyoxal in Candida albicans. In glutathione-depleted Δgcs1, we previously saw that NAD(H)-linked methylglyoxal oxidoreductase (Mgd1) and alcohol dehydrogenase (Adh1) are the most active methylglyoxal scavengers. With methylglyoxal accumulation, disruptants lacking MGD1 or ADH1 exhibit a poor redox state. However, there is little convincing evidence for a reciprocal relationship between methylglyoxal scavenger genes-disrupted mutants and changes in glutathione-(in)dependent redox regulation. Herein, we attempt to demonstrate a functional role for methylglyoxal scavengers, modeled on a triple disruptant (Δmgd1/Δadh1/Δgcs1), to link between antioxidative enzyme activities and their metabolites in glutathione-depleted conditions. Despite seeing elevated methylglyoxal in all of the disruptants, the result saw a decrease in pyruvate content in Δmgd1/Δadh1/Δgcs1 which was not observed in double gene-disrupted strains such as Δmgd1/Δgcs1 and Δadh1/Δgcs1. Interestingly, Δmgd1/Δadh1/Δgcs1 exhibited a significantly decrease in H2O2 and superoxide which was also unobserved in Δmgd1/Δgcs1 and Δadh1/Δgcs1. The activities of the antioxidative enzymes erythroascorbate peroxidase and cytochrome c peroxidase were noticeably higher in Δmgd1/Δadh1/Δgcs1 than in the other disruptants. Meanwhile, Glr1 activity severely diminished in Δmgd1/Δadh1/Δgcs1. Monitoring complementary gene transcripts between double gene-disrupted Δmgd1/Δgcs1 and Δadh1/Δgcs1 supported the concept of an unbalanced redox state independent of the Glr1 activity for Δmgd1/Δadh1/Δgcs1. Our data demonstrate the reciprocal use of Eapx1 and Ccp1 in the absence of both methylglyoxal scavengers; that being pivotal for viability in non-filamentous budding yeast.

• Toxicological Research
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• v.17
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• pp.299-304
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• 2001

Xenobiotics and their reactive intermediates bind to cellular macromolecules and/or generate oxidative stress. which provoke deleterious effects on the cell function. Induction of xenobiotic-biotrans-forming enzymes and antioxidant molecules is an important defense mechanism against such insults. A group of genes involved in the defense mechanism. e.g. genes encoding glutathione S-transferases. NAD(P)H: quinone oxidoreductase, UDP-glucuronosyltransferase (UDP-GT) and ${\gamma}$-glutamylcysteine synthetase (GGCS). have a common regulatory sequence, Antioxidant or Electrophile Responsive Element (ARE/EpRE). Recently. Nrf2. discovered as a homologue of erythroid transcription factor p45 NF-E2, was shown to bind ARE/EpRE and induce the expression of these defense genes. Mice that lack Nrf2 show low basal levels of expression and/or impaired induction of these genes. which makes the animals highly sensitive to xenobiotic toxicity. Indeed. we show here that nrf2-deficient mice had a higher mortality than did the wild-type mice when exposed to acetaminophen (APAP). Detailed analyses of APAP hepatotoxicity in the nrf2 knockout mice indicate that a large amount of reactive APAP metabolites was generated in the livers due to the impaired basal expression of two detoxifying enzyme genes, UDP-GT (Ugt1a6) and GGCS. while the cytochrome P450 content was unchanged. Thus. the studies using the nrf2 knockout mice clearly demonstrate significance of the expression of Nrf2-regulated enzymes in protection against xenobiotic toxicity.

• Biomolecules & Therapeutics
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• v.32 no.1
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• pp.77-83
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• 2024

Alzheimer's disease (AD) is a neurodegenerative disease characterized by neuronal cell death and memory impairment. Corticosterone (CORT) is a glucocorticoid hormone produced by the hypothalamic-pituitary-adrenal axis in response to a stressful condition. Excessive stress and high CORT levels are known to cause neurotoxicity and aggravate various diseases, whereas mild stress and low CORT levels exert beneficial actions under pathophysiological conditions. However, the effects of mild stress on AD have not been clearly elucidated yet. In this study, the effects of low (3 and 30 nM) CORT concentration on Aβ_25-35-induced neurotoxicity in SH-SY5Y cells and underlying molecular mechanisms have been investigated. Cytotoxicity caused by Aβ_25-35 was significantly inhibited by the low concentration of CORT treatment in the cells. Furthermore, CORT pretreatment significantly reduced Aβ_25-35-mediated pro-apoptotic signals, such as increased Bim/Bcl-2 ratio and caspase-3 cleavage. Moreover, low concentration of CORT treatment inhibited the Aβ_25-35-induced cyclooxygenase-2 and pro-inflammatory cytokine expressions, including tumor necrosis factor-α and interleukin-1β. Aβ_25-35 resulted in intracellular accumulation of reactive oxygen species and lipid peroxidation, which were effectively reduced by the low CORT concentration. As a molecular mechanism, low CORT concentration activated the nuclear factor-erythroid 2-related factor 2, a redox-sensitive transcription factor mediating cellular defense and upregulating the expression of antioxidant enzymes, such as NAD(P)H:quinone oxidoreductase, glutamylcysteine synthetase, and manganese superoxide dismutase. These findings suggest that low CORT concentration exerts protective actions against Aβ_25-35-induced neurotoxicity and might be used to treat and/or prevent AD.