• Title/Summary/Keyword: Metabolic Enzymes

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Crosstalk of Zn in Combination with Other Fertilizers Underpins Interactive Effects and Induces Resistance in Tomato Plant against Early Blight Disease

  • Awan, Zoia Arshad;Shoaib, Amna;Khan, Kashif Ali
    • The Plant Pathology Journal
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    • v.35 no.4
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    • pp.330-340
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    • 2019
  • The present study was undertaken to evaluate the integrated effect of zinc (Zn) with other nutrients in managing early blight (EB) disease in tomato. A pot experiment was carried out with basal application of the recommended level of macronutrients [nitrogen, phosphorus and potassium (NPK)] and micronutrients [magnesium (Mg) and boron (B)] in bilateral combination with Zn (2.5 and 5.0 mg/kg) in a completely randomized deigned in replicates. Results revealed that interactive effect of Zn with Mg or B was often futile and in some cases synergistic. Zn with NPK yield synergistic outcome, therefore EB disease was managed significantly (disease incidence: 25% and percent severity index: 13%), which resulted in an efficient signaling network that reciprocally controls nutrient acquisition and uses with improved growth and development in a tomato plant. Thus, crosstalk and convergence of mechanisms in metabolic pathways resulted in induction of resistance in tomato plant against a pathogen which significantly improved photosynthetic pigment, total phenolics, total protein content and defense-related enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL)]. The tremendous increase in total phenolics and PAL activity suggesting their additive effect on salicylic acid which may help the plant to systemically induce resistance against pathogen attack. It was concluded that interactive effect of Zn (5.0 mg/kg) with NPK significantly managed EB disease and showed positive effect on growth, physiological and biochemical attributes therefor use of Zn + NPK is simple and credible efforts to combat Alternaria stress in tomato plants.

Phosphoserine Phosphatase Promotes Lung Cancer Progression through the Dephosphorylation of IRS-1 and a Noncanonical L-Serine-Independent Pathway

  • Park, Seong-Min;Seo, Eun-Hye;Bae, Dong-Hyuck;Kim, Sung Soo;Kim, Jina;Lin, Weiwei;Kim, Kyung-Hee;Park, Jong Bae;Kim, Yong Sung;Yin, Jinlong;Kim, Seon-Young
    • Molecules and Cells
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    • v.42 no.8
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    • pp.604-616
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    • 2019
  • Phosphoserine phosphatase (PSPH) is one of the key enzymes of the L-serine synthesis pathway. PSPH is reported to affect the progression and survival of several cancers in an L-serine synthesis-independent manner, but the mechanism remains elusive. We demonstrate that PSPH promotes lung cancer progression through a noncanonical L-serine-independent pathway. PSPH was significantly associated with the prognosis of lung cancer patients and regulated the invasion and colony formation of lung cancer cells. Interestingly, L-serine had no effect on the altered invasion and colony formation by PSPH. Upon measuring the phosphatase activity of PSPH on a serine-phosphorylated peptide, we found that PSPH dephosphorylated phospho-serine in peptide sequences. To identify the target proteins of PSPH, we analyzed the protein phosphorylation profile and the PSPH-interacting protein profile using proteomic analyses and found one putative target protein, IRS-1. Immunoprecipitation and immunoblot assays validated a specific interaction between PSPH and IRS-1 and the dephosphorylation of phospho-IRS-1 by PSPH in lung cancer cells. We suggest that the specific interaction and dephosphorylation activity of PSPH have novel therapeutic potential for lung cancer treatment, while the metabolic activity of PSPH, as a therapeutic target, is controversial.

Engineering of Biosynthesis Pathway and NADPH Supply for Improved L-5-Methyltetrahydrofolate Production by Lactococcus lactis

  • Lu, Chuanchuan;Liu, Yanfeng;Li, Jianghua;Liu, Long;Du, Guocheng
    • Journal of Microbiology and Biotechnology
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    • v.31 no.1
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    • pp.154-162
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    • 2021
  • L-5-methyltetrahydrofolate (5-MTHF) is one of the biological active forms of folate, which is widely used as a nutraceutical. However, low yield and serious pollution associated with the chemical synthesis of 5-MTHF hampers its sustainable supply. In this study, 5-MTHF production was improved by engineering the 5-MTHF biosynthesis pathway and NADPH supply in Lactococcus lactis for developing a green and sustainable biosynthesis approach. Specifically, overexpressing the key rate-limiting enzyme methylenetetrahydrofolate reductase led to intracellular 5-MTHF accumulation, reaching 18 ㎍/l. Next, 5-MTHF synthesis was further enhanced by combinatorial overexpression of 5-MTHF synthesis pathway enzymes with methylenetetrahydrofolate reductase, resulting in 1.7-fold enhancement. The folate supply pathway was strengthened by expressing folE encoding GTP cyclohydrolase I, which increased 5-MTHF production 2.4-fold to 72 ㎍/l. Furthermore, glucose-6-phosphate dehydrogenase was overexpressed to improve the redox cofactor NADPH supply for 5-MTHF biosynthesis, which led to a 60% increase in intracellular NADPH and a 35% increase in 5-MTHF production (97 ㎍/l). To reduce formation of the by-product 5-formyltetrahydrofolate, overexpression of 5-formyltetrahydrofolate cyclo-ligase converted 5-formyltetrahydrofolate to 5,10-methyltetrahydrofolate, which enhanced the 5-MTHF titer to 132 ㎍/l. Finally, combinatorial addition of folate precursors to the fermentation medium boosted 5-MTHF production, reaching 300 ㎍/l. To the best of our knowledge, this titer is the highest achieved by L. lactis. This study lays the foundation for further engineering of L. lactis for efficient 5-MTHF biosynthesis.

The dehiscence process in Panax ginseng seeds and the stigmasterol biosynthesis pathway in terms of metabolomics

  • Min, Jung Eun;Long, Nguyen Phuoc;Hong, Ji Yeon;Kim, Sun Jo;Anh, Nguyen Hoang;Wang, Daijie;Wang, Xiao;Park, Jeong Hill;Kwon, Sung Won;Lee, Seul Ji
    • Journal of Ginseng Research
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    • v.46 no.2
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    • pp.225-234
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    • 2022
  • Background: Ginseng, officially known as Panax ginseng Meyer, has been traditionally used as a medicinal herb, particularly in Asia. Ginseng is propagated from seeds; however, seed germination is challenging, especially in its natural environment on farms. The seeds typically exhibit morphophysiological dormancy and require release from both morphological and physiological dormancy before germination. Although some studies have proposed methods for increasing seed germination rates, the underlying mechanisms of its dormancy release process remain unclear. Here, we investigated metabolic alterations during dehiscence in P. ginseng to determine their potential roles in dormancy release. Methods: We compared the ginseng seed metabolome before and after dehiscence and the ginsenoside and phytosterol compositions of the seeds in both periods in the presence of related enzymes. Results: After seed dehiscence, the sugar, amino acid, and squalene concentrations were significantly altered, phytosterols associated with the stigmasterol biosynthesis pathway were increased, while ginsenoside and brassinosteroid levels were not significantly altered. In addition, squalene epoxidase, cycloartenol synthase, 24-methylenesterol C-methyltransferase, and the stigmasterol biosynthesis pathway were activated. Conclusion: Overall, our findings suggest that morphological activities that facilitate ginseng seed growth are the primary phenomena occurring during the dehiscence process. This study improves the understanding of P. ginseng germination processes and promotes further research of its germination and cultivation.

Glutamine Inhibits TNF-α-induced Cytosolic Phospholipase A2 Activation via Upregulation of MAPK Phosphatase-1

  • Yoon, So Young;Jeong, Soo-Yeon;Im, Suhn-Young
    • Biomedical Science Letters
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    • v.27 no.4
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    • pp.223-230
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    • 2021
  • Tumor necrosis factor alpha (TNF-α) is a principal regulator of inflammation and immunity. The proinflammatory properties of TNF-α can be attributed to its ability to activate the enzyme cytosolic phospholipase A2 (cPLA2), which generates potent inflammatory lipid mediators, eicosanoids. L-glutamine (Gln) plays physiologically important roles in various metabolic processes. We have reported that Gln has a potent anti-inflammatory activity via rapid upregulation of mitogen-activated protein kinases (MAPKs) phosphatase (MKP)-1, which preferentially dephosphorylates the key proinflammatory enzymes, p38 MAPK and cytosolic phospholipase A2 (cPLA2). In this study, we have investigated whether Gln could inhibit TNF-α-induced cPLA2 activation. Gln inhibited TNF-α-induced increases in cPLA2 phosphorylation in the lungs and blood levels of the cPLA2 metabolites, leukotrine B4 (LTB4) (lipoxygenase metabolite) and prostaglandin E2 (PGE2) (cyclooxygenase metabolite). TNF-α increased p38 and cPLA2 phosphorylation and blood levels of LTB4 and PGE2, which were blocked by the p38 inhibitor SB202190. Gln inhibited TNF-α-induced p38 and cPLA2 phosphorylation and production of the cPLA2 metabolites. Such inhibitory activity of Gln was no longer observed in MKP-1 small interfering RNA-pretreated animals. Our data indicate that Gln inhibited TNF-α-induced cPLA2 phosphorylation through MKP-1 induction/p38 inhibition, and suggest that the utility of Gln in inflammatory diseases in which TNF-α plays a major role in their pathogenesis.

Efficacy of nobiletin in improving hypercholesterolemia and nonalcoholic fatty liver disease in high-cholesterol diet-fed mice

  • Kim, Young-Je;Yoon, Dae Seong;Jung, Un Ju
    • Nutrition Research and Practice
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    • v.15 no.4
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    • pp.431-443
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    • 2021
  • BACKGROUND/OBJECTIVES: Nobiletin (NOB), a citrus flavonoid, is reported to have beneficial effects on cardiovascular and metabolic health. However, there is limited research investigating the effect of long-term supplementation with low-dose NOB on high-cholesterol diet (HCD)-induced hypercholesterolemia and non-obese nonalcoholic fatty liver disease (NAFLD). Therefore, we investigated the influence of NOB on hypercholesterolemia and NAFLD in HCD-fed mice. SUBJECTS/METHODS: C57BL/6J mice were fed a normal diet (ND) or HCD (35 kcal% fat, 1.25% cholesterol, 0.5% cholic acid) with or without NOB (0.02%) for 20 weeks. RESULTS: HCD feeding markedly reduced the final body weight compared to ND feeding, with no apparent energy intake differences. NOB supplementation suppressed HCD-induced weight loss without altering energy intake. Moreover, NOB significantly decreased the total cholesterol (TC) levels and the low-density lipoprotein (LDL)/very-LDL-cholesterol to TC ratio, and increased the high-density lipoprotein-cholesterol/TC ratio in plasma, compared to those for HCD feeding alone. The plasma levels of inflammatory and atherosclerosis markers (C-reactive protein, oxidized LDL, interleukin [IL]-1β, IL-6, and plasminogen activator inhibitor-1) were significantly lower, whereas those of anti-atherogenic adiponectin and paraoxonase were higher in the NOB-supplemented group than in the HCD control group. Furthermore, NOB significantly decreased liver weight, hepatic cholesterol and triglyceride contents, and lipid droplet accumulation by inhibiting messenger RNA expression of hepatic genes and activity levels of cholesterol synthesis-, esterification-, and fatty acid synthesis-associated enzymes, concomitantly enhancing fatty acid oxidation-related gene expression and enzyme activities. Dietary NOB supplementation may protect against hypercholesterolemia and NAFLD via regulation of hepatic lipid metabolism in HCD-fed mice; these effects are associated with the amelioration of inflammation and reductions in the levels of atherosclerosis-associated cardiovascular markers. CONCLUSIONS: The present study suggests that NOB may serve as a potential therapeutic agent for the treatment of HCD-induced hypercholesterolemia and NAFLD.

Severe SARS-CoV-2 Infection With Multiorgan Involvement Followed by MIS-C in an Adolescent

  • Bomi Lim;Su-Mi Shin;Mi Seon Han
    • Pediatric Infection and Vaccine
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    • v.29 no.3
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    • pp.155-160
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    • 2022
  • Children and adolescents with coronavirus disease 2019 (COVID-19) generally have mild symptoms. Severe infection due to severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) involving multiorgan dysfunction is rare in this population. Herein, we present an unusual case of severe SARS-CoV-2 infection with multiorgan involvement followed by multisystem inflammatory syndrome in children (MIS-C) in a vaccinated 16-year-old boy. The patient was unconscious on initial presentation, and had severe paralytic ileus. On laboratory examination, there was severe metabolic acidosis, lymphocytopenia, thrombocytopenia, elevated inflammatory markers, elevated liver enzymes, and evidence of acute kidney injury with proteinuria and hematuria. His symptoms improved with the administration of remdesivir and dexamethasone. The patient briefly experienced MIS-C 2 weeks after the diagnosis of COVID-19, but the patient was discharged without any complications.

Functional Characterization of Drosophila melanogaster CYP6A8 Fatty Acid Hydroxylase

  • Sang-A Lee;Vitchan Kim;Byoungyun Choi;Hyein Lee;Young-Jin Chun;Kyoung Sang Cho;Donghak Kim
    • Biomolecules & Therapeutics
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    • v.31 no.1
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    • pp.82-88
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    • 2023
  • Genomic analysis indicated that the genome of Drosophila melanogaster contains more than 80 cytochrome P450 genes. To date, the enzymatic activity of these P450s has not been extensively studied. Here, the biochemical properties of CYP6A8 were characterized. CYP6A8 was cloned into the pCW vector, and its recombinant enzyme was expressed in Escherichia coli and purified using Ni2+-nitrilotriacetate affinity chromatography. Its expression level was approximately 130 nmol per liter of culture. Purified CYP6A8 exhibited a low-spin state in the absolute spectra of the ferric forms. Binding titration analysis indicated that lauric acid and capric acid produced type I spectral changes, with Kd values 28 ± 4 and 144 ± 20 µM, respectively. Ultra-performance liquid chromatography-mass spectrometry analysis showed that the oxidation reaction of lauric acid produced (ω-1)-hydroxylated lauric acid as a major product and ω-hydroxy-lauric acid as a minor product. Steady-state kinetic analysis of lauric acid hydroxylation yielded a kcat value of 0.038 ± 0.002 min-1 and a Km value of 10 ± 2 µM. In addition, capric acid hydroxylation of CYP6A8 yielded kinetic parameters with a kcat value of 0.135 ± 0.007 min-1 and a Km value of 21 ± 4 µM. Because of the importance of various lipids as carbon sources, the metabolic analysis of fatty acids using CYP6A8 in this study can provide an understanding of the biochemical roles of P450 enzymes in many insects, including Drosophila melanogaster.

High-mobility Group Box 1 Induces the Epithelial-mesenchymal Transition, Glycolytic Switch, and Mitochondrial Repression via Snail Activation (HMGB1/Snail cascade에 의한 epithelial-mesenchymal transition 및 glycolytic switch, mitochondrial repression 유도)

  • Lee, Su Yeon;Ju, Min Kyung;Jeon, Hyun Min;Kim, Cho Hee;Park, Hye Gyeong;Kang, Ho Sung
    • Journal of Life Science
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    • v.29 no.11
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    • pp.1179-1191
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    • 2019
  • Cancer cells undergo the epithelial-mesenchymal transition (EMT) and show unique oncogenic metabolic phenotypes such as the glycolytic switch (Warburg effect) which are important for tumor development and progression. The EMT is a critical process for tumor invasion and metastasis. High-mobility group box 1 (HMGB1) is a chromatin-associated nuclear protein, but it acts as a damage-associated molecular pattern molecule when released from dying cells and immune cells. HMGB1 induces the EMT, as well as invasion and metastasis, thereby contributing to tumor progression. Here, we show that HMGB1 induced the EMT by activating Snail. In addition, the HMGB1/Snail cascade was found induce a glycolytic switch. HMGB1 also suppressed mitochondrial respiration and cytochrome c oxidase (COX) activity by a Snail-dependent reduction in the expression of the COX subunits COXVIIa and COXVIIc. HMGB1 also upregulated the expression of several key glycolytic enzymes, including hexokinase 2 (HK2), phosphofructokinase-2/fructose-2,6-bisphosphatase 2 (PFKFB2), and phosphoglycerate mutase 1 (PGAM1), in a Snail-dependent manner. However, HMGB1 was found to regulate some other glycolytic enzymes including lactate dehydrogenases A and B (LDHA and LDHB), glucose transporter 1 (GLUT1), and monocarboxylate transporters 1 and 4 (MCT1 and 4) in a Snail-independent manner. Transfection with short hairpin RNAs against HK2, PFKFB2, and PGAM1 prevented the HMGB1-induced EMT, indicating that glycolysis is associated with HMGB1-induced EMT. These findings demonstrate that HMGB1 signaling induces the EMT, glycolytic switch, and mitochondrial repression via Snail activation.

Carbohydrate Metabolism in Preimplantation Stage Embryos and the Role of Metabolites (착상전 초기 배아에서 탄수화물 대사와 그 대사물의 역할)

  • Cheon, Yong-Pil
    • Development and Reproduction
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    • v.12 no.1
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    • pp.19-30
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    • 2008
  • Proper development of fertilized oocyte to blastocyst is a key step in mammalian development to implantation. During development of preimplantation embryos, the mammalian embryo needs supply the energy substrate for keep viability. Usually mammalian oocyte get substrate especially energy substrate from oviduct and uterus, because it does not store much substrate into cytoplasm during oogenesis. Carbohydrates are known as a main energy substrate for preimplantation stage embryos. Glucose, lactate and pyruvate are essential component in preimplantation embryo culture media and there are stage specific preferences to them. Glucose transporter and $H^+$-monocarboxylate cotransporter are a main mediator for carbohydrate transport and those expression levels are primarily under the control of intrinsic or extrinsic factors like insulin and glucose. Other organic substances, amino acids, lipids and nucleotides are used as energy substance and cellular regulation factor. Though since 1960s, successful development of fertilized embryo to blastocyst has been accomplished with chemically defined medium for example BWW and give rise to normal offspring in mammals, the role of metabolites and the regulation of intermediary metabolism are still poorly understood. Glucose may permit expression of metabolic enzymes and transporters in compacting morula, capable of generating the energy required for blastocyst formation. In addition, it has been suggested that the cytokines can modulate the metabolic rate of carbohydrate in embryos and regulate the preimplantation embryonic development through control the metabolic rate. Recently we showed that lactate can be used as a mediator for preimplantation embryonic development. Those observations indicate that metabolites of carbohydrate are required by the early embryo, not only as an energy source, but also as a key substrate for other regulatory and biosynthetic pathways. In addition metabolites of carbohydrate may involve in cellular activity during development of preimplantation embryos. It is suggested that through these regulation and with other regulation mechanisms, embryo and uterus can prepare the embryo implantation and further development, properly.

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