• Title/Summary/Keyword: Enzyme regulation

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Hypermethylation of Promoter Region of LATS1 - a CDK Interacting Protein in Oral Squamous Cell Carcinomas - a Pilot Study in India

  • Reddy, Vijaya Ramakrishna;Annamalai, Thangavelu;Narayanan, Vivek;Ramanathan, Arvind
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1599-1603
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    • 2015
  • Background: Epigenetic silencing of tumor suppressor genes due to promoter hypermethylation is one of the frequent mechanisms observed in cancers. Hypermethylation of several tumor suppressor genes involved in cell cycle regulation has been reported in many types of tumors including oral squamous cell carcinomas. LATS1 (Large Tumor Suppressor, isoform 1) is a novel tumor suppressor gene that regulates cell cycle progression by forming complexes with the cyclin dependent kinase, CDK1. Promoter hypermethylation of the LATS1 gene has been observed in several carcinomas and also has been linked with prognosis. However, the methylation status of LATS1 in oral squamous cell carcinomas is not known. As oral cancer is one of the most prevalent forms of cancer in India, the present study was designed to investigate the methylation status of LATS1 promoter and associate it with histopathological findings in order to determine any associations of the genetic status with stage of differentiation. Materials and Methods: Tumor chromosomal DNA isolated from biopsy tissues of thirteen oral squamous cell carcinoma biopsy tissues were subjected to digestion with methylation sensitive HpaII enzyme followed by amplification with primers flanking CCGG motifs in promoter region of LATS1 gene. The PCR amplicons were subsequently subjected to agarose gel electrophoresis along with undigested amplification control. Results: HpaII enzyme based methylation sensitive PCR identified LATS1 promoter hypermethylation in seven out of thirteen oral squamous cell carcinoma samples. Conclusions: The identification of LATS1 promoter hypermethylation in seven oral squamous cell carcinoma samples (54%), which included one sample with epithelial dysplasia, two early invasive and one moderately differentiated lesions indicates that the hypermethylation of this gene may be one of the early event during carcinogenesis. To the best of our knowledge, this is the first study to have explored and identified positive association between LATS1 promoter hypermethylation with histopathological features in oral squamous cell carcinomas.

Anti-Inflammatory and Antioxidative Effects of Gracilaria textorii Ethanol Extract in LPS-PG-Stimulated Human Gingival Fibroblast-1 Cells (사람 치은섬유모세포에서 잎꼬시래기 에탄올 추출물의 항염증 및 항산화 효과)

  • Park, Chungmu;Yoon, Hyunseo
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.61-69
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    • 2019
  • Purpose : Human gingival fibroblast cell is one of the the main cell types in periodontal tissue, which they can show anti-inflammatory activity through the production of numerous lines of inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and interleukins. Porphyromonas gingivalis, one of the oral pathogens, has reported to play a critical role in the development of periodontal diseases. This study aimed to investigate anti-inflammatory and antioxidative activities of Gracilaria textorii ethanol extract (GTEE) in P. gingivalis derived lipopolysaccharide (LPS-PG) stimulated human gingival fibroblast (HGF)-1 cell line. Methods : In order to analyze anti-inflammatory and antioxidative activities of GTEE in HGF-1 cell line, NOS enzyme activity, expression levels of iNOS, COX-2, NAD(P)H quinone dehydrogenase (NQO)1 and their transcription factors were estimated by Griess reaction and western hybridization. Results : LPS-PG induced overexpression of iNOS and COX-2, which was significantly attenuated by GTEE treatment in a dose-dependent manner without any cytotoxicity. In addition, intracellular NOS activity was in accordance with the result of iNOS expression. Due to important role in the regulation of inflammatory responses, phosphorylated status of p65 and c-jun, each subunit of nuclear factor (NF)-κB and activator protein (AP)-1, was also dose-dependently ameliorated by GTEE treatment. One of phase II enzymes, NQO1, and its transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), were analyzed since elevated phase II enzyme expression inhibited inflammatory response, which was significantly elevated by GTEE treatment in HGF-1 cell line. Conclusion : In conclusion, GTEE mitigated LPS-PG-stimulated inflammatory responses by attenuating NF-κB and AP-1 activation as well as accelerating NQO1 and Nrf2 expression in HGF-1 cell line. These results indicate that GTEE might be utilized a promising strategy for potential anti-inflammatory agent in periodontal diseases.

Effects of low temperature on the IAA degradation system in etiolated pea(Pisum sativum L. var. Sparkle) seedlings (백색 완두유묘의 IAA분해효소계에 미치는 저온의 영향)

  • Park, Ro-Dong;Shin, Yong-Kwang;Kim, Kwang-Sik;Park, Chang-Kyu
    • Applied Biological Chemistry
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    • v.33 no.2
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    • pp.125-128
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    • 1990
  • Previous work has shown that the levels of free and total IAA and tryptophan decrease on exposing etiolated pea (Pisum sativum L. var. Sparkle) seedlings grown at $25^{\circ}C$ to $5^{\circ}C$ for 3 days, suggesting that low temperature down-regulates the level of endogenous IAA, in part, by reducing tryptophan biosynthesis. To understand, in this study, the effect of low temperature on the regulation of IAA degradation system in etiolated pea seedlings, enzyme levels of IAA degradation system and hydrogen peroxide content were analyzed during and after chilling($5^{\circ}C$) 6-day-old pea seedlings grown at $25^{\circ}C$. The levels of IAA oxidase and peroxidase increased during chilling and gradually restored to the level of control on termination of chilling. Catalase levels decreased upon chilling and increased to the level of control on termination of chilling. $H_2O_2$ was accumulated during chilling up to the level of $5.5\;{\mu}mol/g$ fresh weight while at $25^{\circ}C$ maintained a relatively constant $H_2O_2$ level of $4\;{\mu}mol/g$ FW. All together, it appears that low temperature, in part, by increasing enzyme levels of IAA degradation system and accumulating $H_2O_2$, down-regulates endogenous level of IAA in etiolated pea shoots.

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Isolation of a Thermophilic Mutant, Talaromyces luteus 2004 in relation to the Regulation of Carboxymethylcellulase Production and Enzymatic characteristics (고온성 변이균주 Talaromyces luteus 2004의 분리와 Carboxymethylcellulase의 생성 조절 및 효소의 특성)

  • Hong, Mi-Kyung;Han, Hyo-Young;Jung, Young-Hee;Min, Kyung-Hee
    • The Korean Journal of Mycology
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    • v.24 no.3 s.78
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    • pp.206-213
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    • 1996
  • Talaromyces luteus 2004, a thermophilic mutant of T. luteus 6112 was obtained by mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. T. luteus 2004 produced thermophilic carboxymethylcellulase (CMCase), and other polysaccharide enzymes: avicellase, xylanase, and ${\beta}-glucosidase$. Induction of CMCase production was shown at the highest level in 3% carboxymethylcellulose (CMC) minimal broth, indicating that CMC could work as an inducer. However, glucose and D-cellobiose showed catabolite repression for CMCase production which was under the control of CMC utilization. Optimal conditions for CMCase activity were at $70^{\circ}C$ and pH 4.0, suggesting that CMCase of T. luteus 2004 was a thermophilic enzyme.

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Effect of Phosphodiesterase in Regulating the Activity of Lysosomes in the HeLa Cell Line

  • Hong, Eun-Seon;Kim, Bit-Na;Kim, Yang-Hoon;Min, Jiho
    • Journal of Microbiology and Biotechnology
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    • v.27 no.2
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    • pp.372-379
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    • 2017
  • The transport of lysosomal enzymes into the lysosomes depends on the phosphorylation of their chains and the binding of the phosphorylated residues to mannose-6-phosphate receptors. The efficiency of separation depends more on the phosphodiesterases (PDEs) than on the activity of the phosphorylation of mannose residues and can be determined in vitro. PDEs play important roles in regulation of the activation of lysosomes. The expression of proteins was confirmed by western blotting. All PDE4 series protein expression was reduced in high concentrations of rolipram. As a result of observing the fluorescence intensity after rolipram treatment, the lysosomal enzyme was activated at low concentrations and suppressed at high concentrations. High concentrations of rolipram recovered the original function. Antimicrobial activity was not shown in either 10 or $100{\mu}M$ concentrations of rolipram in treated HeLa cells in vitro. However, the higher anticancer activity at lower rolipram concentration was shown in lysosomal enzyme treated with $10{\mu}M$ of rolipram. The anticancer activity was confirmed through cathepsin B and D assay. Tranfection allowed examination of the relationship between PDE4 and lysosomal activity in more detail. Protein expression was confirmed to be reduced. Fluorescence intensity showed decreased activity of lysosomes and ROS in cells transfected with the antisense sequences of PDE4 A, B, C, and D. PDE4A showed anticancer activity, whereas lysosome from cells transfected with the antisense sequences of PDE4 B, C, and D had decreased anticancer activity. These results showed the PDE4 A, B, C, and D are conjunctly related with lysosomal activity.

Expression of a Glutathione Reductase from Brassica rapa subsp. pekinensis Enhanced Cellular Redox Homeostasis by Modulating Antioxidant Proteins in Escherichia coli

  • Kim, Il-Sup;Shin, Sun-Young;Kim, Young-Saeng;Kim, Hyun-Young;Yoon, Ho-Sung
    • Molecules and Cells
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    • v.28 no.5
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    • pp.479-487
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    • 2009
  • Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

  • Kang, Sa-Ouk;Kwak, Min-Kyu
    • 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.

Subcutaneous Streptococcus dysgalactiae GAPDH vaccine in mice induces a proficient innate immune response

  • Ran An;Yongli Guo;Mingchun Gao;Junwei Wang
    • Journal of Veterinary Science
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    • v.24 no.5
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    • pp.72.1-72.16
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    • 2023
  • Background: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the surface of Streptococcus dysgalactiae, coded with gapC, is a glycolytic enzyme that was reported to be a moonlighting protein and virulence factor. Objective: This study assessed GAPDH as a potential immunization candidate protein to prevent streptococcus infections. Methods: Mice were vaccinated subcutaneously with recombinant GAPDH and challenged with S. dysgalactiae in vivo. They were then evaluated using histological methods. rGAPDH of mouse bone marrow-derived dendritic cells (BMDCs) was evaluated using immunoblotting, reverse transcription quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay methods. Results: Vaccination with rGAPDH improved the survival rates and decreased the bacterial burdens in the mammary glands compared to the control group. The mechanism by which rGAPDH vaccination protects against S. dysgalactiae was investigated. In vitro experiments showed that rGAPDH boosted the generation of interleukin-10 and tumor necrosis factor-α. Treatment of BMDCs with TAK-242, a toll-like receptor 4 inhibitor, or C29, a toll-like receptor 2 inhibitor, reduced cytokines substantially, suggesting that rGAPDH may be a potential ligand for both TLR2 and TLR4. Subsequent investigations showed that rGAPDH may activate the phosphorylation of MAPKs and nuclear factor-κB. Conclusions: GAPDH is a promising immunization candidate protein for targeting virulence and enhancing immune-mediated protection. Further investigations are warranted to understand the mechanisms underlying the activation of BMDCs by rGAPDH in a TLR2- and TLR4-dependent manner and the regulation of inflammatory cytokines contributing to mastitis pathogenesis.

Telomerase Activity is Constitutively Expressed in the Murine $CD8^+$ T Cells and Controlled Transcriptionally and Post-Translationally

  • Kim, SoJung;Kim, MiHyung;Kim, KilHyoun
    • IMMUNE NETWORK
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    • v.4 no.3
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    • pp.166-175
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    • 2004
  • Background: Telomerase, a ribonucleoprotein enzyme capable of synthesizing telomeric repeats, attracts attention for its possible role in determining the replicative capacity of normal somatic cells, transformed cells, and cells of the germline lineage. Differently from normal somatic cells with no telomerase activity, normal lymphocytes has been reported to have telomerase activity comparable to that found in transformed cells during development and activation, which substantiate a role in supporting the capacity of lymphocytes for extensive clonal expansion. Methods: Here, in order to define the telomerase regulation in murine T lymphocytes, telomerase activity in cloned murine $CD8^+$ T cells and naive $CD8^+$ T cells isolated from C57BL/6 mice was examined. Next, the regulatory mechanism of telomerase activity at transcriptional and post- translational levels was investigated by determining the expression level of the TERT protein, a key component for telomerase activity. Results: It was demonstrated that telomerase activity was expressed in an inactivated state as well as in an activated state in the murine $CD8^+$ T lymphocytes by using TRAP assay. The increase of telomerase activity was partially dependent on the net increase of TERT expression. Also, telomerase activity was decreased after treatment with protein kinase inhibitors, indicating that telomerase activation was prevented by inhibition of phosphorylation. Conclusion: Therefore, these results suggest that telomerase activity is constitutively expressed in the murine resting T lymphocytes and controlled by both transcriptional regulation and post- ranslational modifications.

Mitigating Effect of Jageum-jung on Dextran Sulfate Sodium-induced Ulcerative Colitis through Anti-inflammatory Regulation (항염증조절을 통한 자금정의 DSS 유도 궤양성 대장염 완화 효과)

  • Choi, Jun-yong;Ahn, Sang-hyun;Shih, Yin-hao;Sa, Bok-suk;Kim, Ki-bong
    • The Journal of Internal Korean Medicine
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    • v.38 no.6
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    • pp.944-954
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    • 2017
  • Objectives: This study investigated the anti-inflammatory effects of Jageum-jung extract on Dextran sulfate sodium (DSS-induced) ulcerative colitis in mice. Methods: Ulcerative colitis was induced by DSS in Balb/C male mice. Ten mice were assigned to each of four groups: Ctrl (control), UE (ulcerative colitis-induced), PT (treated with pentasaccharide after induction of ulcerative colitis), and JT (treated with Jageum-jung extract after induction of ulcerative colitis). The effects of Jageum-jung extract were measured by restoration of the length of the intestine, degree of mucosal damage as seen with histochemistry, and changes of p-IkB, iNOS, COX-2, and caspase-3 determined by immunohistochemistry. Results: The recovered intestinal length of the JT group was longer than that of the UE group. In the colon mucosa of JT group, hemorrhagic lesions were reduced, and the mucus barrier was recovered. This group also showed inhibited production of inflammatory enzymes (iNOS, COX-2) through regulation of proinflammatory enzyme (NF-kB, p65) activity in the colon. In addition, caspase 3 activation induced apoptosis. By GC/MS analysis, azetidine was identified. Conclusions: This study confirmed the anti-inflammatory effects of jageum-jung extract, and suggests the possibility of using Jageum-jung extract to treat ulcerative colitis. Further experiments and research on the mechanism of Jageum-jung effects are needed.