• Title/Summary/Keyword: D-Alanine

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Mutational Analysis of the Metal-binding Sites of Peroxide Sensor PerR

  • Won, Young-Bin;Ji, Chang-Jun;Cho, Ju-Hyun;Lee, Jin-Won
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1573-1576
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    • 2010
  • Bacillus subtilis PerR is a metal-dependent peroxide-sensing transcription factor which uses metal-catalyzed histidine oxidation for peroxide-sensing. PerR contains two metal binding sites, one for structural $Zn^{2+}$ and the other for the regulatory/peroxide-sensing metal. Here we investigated the effect of mutations at both the structural and regulatory metal binding sites on the oxidation of either H37 or H91, two of the peroxide-sensing ligands. All four serine substitution mutants at the structural $Zn^{2+}$ site (C96S, C99S, C136S and C139S) exhibited no detectable oxidation at histidine residues. Two of the alanine substitution mutants at regulatory metal site (H37A and D85A) exhibited selective oxidation preferentially at the H91-containing tryptic peptide, whereas no oxidation was detected in the other mutants (H91A, H93A and D104A). Our results suggest that the cysteine residues coordinating structural $Zn^{2+}$ are essential for peroxide sensing by PerR, and that the C-terminal regulatory metal binding site composed of H91, H93 and D104 can bind $Fe^{2+}$, providing a possible explanation for the peroxide sensing mechanisms by PerR.

Hepatoprotective Effects of Potato Peptide against D-Galactosamine-induced Liver Injury in Rats

  • Ohba, Kiyoshi;Han, Kyu-Ho;Liyanage, Ruvini;Nirei, Megumi;Hashimoto, Naoto;Shimada, Ken-ichiro;Sekikawa, Mitsuo;Sasaki, Keiko;Lee, Chi-Ho;Fukushima, Michihiro
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1178-1184
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    • 2008
  • The effect of some peptides on hepatoprotection and cecal fermentation against D-galactosamine (GalN)-treated rats was studied. In acute hepatic injury tests, serum alanine aminotransferase (ALT), aspartate aminotranferase (AST), and lactic dehydrogenase (LDH) activities were remarkably increased after injection of GalN. However, potato and soybean peptides significantly decreased GalN-induced alterations of serum ALT and AST activities. Hepatic thiobarbituric acid-reactive substance (TBARS) concentration in GalN-treated groups fed potato and soybean peptides was significantly lower than that in GalN-treated control group. Hepatic glutathione level in the GalN-treated group fed potato peptide was significantly higher than that in GalN-treated control group. Furthermore, cecal Lactobacillus level in GalN-treated groups fed potato and soybean peptides was significantly higher than that in GalN-treated control group, and cecal short-chain fatty acid concentrations in GalN-treated group fed potato peptide were significantly higher than in GalN-treated control group. These results indicate that potato peptide may improve the cecal fermentation and prevent the GalN-induced liver damage in rats.

Effect of Pesticide Residue in Muscle and Fat Tissue of Pigs Treated with Propiconazole

  • Jeong, Jin Young;Kim, Byeonghyeon;Ji, Sang Yun;Baek, Youl Chang;Kim, Minji;Park, Seol Hwa;Kim, Ki Hyun;Oh, Sang-Ik;Kim, Eunju;Jung, Hyunjung
    • Food Science of Animal Resources
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    • v.41 no.6
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    • pp.1022-1035
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    • 2021
  • This study estimated the effect of exposure to propiconazole through implementation and residues in finishing pigs. We analyzed the expression of fibrosis-related genes and performed histological analysis of the blood, liver, kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82 mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues were performed using liquid chromatography mass spectrometry, real-time PCR, and Masson's trichrome staining, respectively. Final body weight did not differ among groups. However, genes involved in fibrosis were significantly differentially regulated in response to propiconazole concentrations. Glucose, alanine aminotransferase, and total bilirubin levels were significantly increased compared with those in the control group, while alkaline phosphatase level was decreased (p<0.05) after exposure to propiconazole. The residue limits of propiconazole were increased in the finishing phase at 4.41 and 8.82 mg/kg bw/d. The liver, kidney, and ileum showed blue staining after propiconazole treatment, confirmed by Masson's trichrome staining. In conclusion, these findings suggest that propiconazole exposure disturbs the expression of fibrosis-related genes. This study on dietary propiconazole in pigs can provide a basis for determining maximum residue limits and a better understanding of metabolism in pigs and meat products.

Ginsenoside Rk1 ameliorates paracetamol-induced hepatotoxicity in mice through inhibition of inflammation, oxidative stress, nitrative stress and apoptosis

  • Hu, Jun-Nan;Xu, Xing-Yue;Li, Wei;Wang, Yi-Ming;Liu, Ying;Wang, Zi;Wang, Ying-Ping
    • Journal of Ginseng Research
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    • v.43 no.1
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    • pp.10-19
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    • 2019
  • Background: Frequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAP-induced hepatotoxicity and investigate the underlying mechanisms for the first time. Methods: Mice were treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, allmice treated with 250mg/kg APAP exhibited severeliverinjury after 24 h, and hepatotoxicitywas assessed. Results: Our results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-$1{\beta}$ compared with the APAP group. Meanwhile, hepatic antioxidants, including superoxide dismutase and glutathione, were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effects were associated with a significant increase of cytochrome P450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis. Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group. Conclusion: The results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.

Loss of RAR-α and RXR-α and enhanced caspase-3-dependent apoptosis in N-acetyl-p-aminophenol-induced liver injury in mice is tissue factor dependent

  • Abdel-Bakky, Mohamed Sadek;Helal, Gouda Kamel;El-Sayed, El-Sayed Mohamed;Amin, Elham;Alqasoumi, Abdulmajeed;Alhowail, Ahmad;Abdelmoti, Eman Sayed Said;Saad, Ahmed Saad
    • The Korean Journal of Physiology and Pharmacology
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    • v.25 no.5
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    • pp.385-393
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    • 2021
  • Tissue factor (TF) activates the coagulation system and has an important role in the pathogenesis of various diseases. Our previous study stated that retinoid receptors (RAR-α and RXR-α) are released as a lipid droplet in monocrotaline/lipopolysaccharide-induced idiosyncratic liver toxicity in mice. Herein, the interdependence between the release of retinoid receptors RAR-α and RXR-α and TF in N-acetyl-p-aminophenol (APAP)-induced mice liver toxicity, is investigated. Serum alanine transaminase (ALT) level, platelet and white blood cells (WBCs) counts, protein expression of fibrin, TF, cyclin D1 and cleaved caspase-3 in liver tissues are analyzed. In addition, histopathological evaluation and survival study are also performed. The results indicate that using of TF-antisense (TF-AS) deoxyoligonucleotide (ODN) injection (6 mg/kg), to block TF protein synthesis, significantly restores the elevated level of ALT and WBCs and corrects thrombocytopenia in mice injected with APAP. TF-AS prevents the peri-central overexpression of liver TF, fibrin, cyclin D1 and cleaved caspase-3. The release of RXR-α and RAR-α droplets, in APAP treated sections, is inhibited upon treatment with TF-AS. In conclusion, the above findings designate that the released RXR-α and RAR-α in APAP liver toxicity is TF dependent. Additionally, the enhancement of cyclin D1 to caspase-3-dependent apoptosis can be prevented by blocking of TF protein synthesis.

Cathepsin D Expression in Oral Squamous Cell Carcinoma and Cancer-Associated Fibroblasts: A Preliminary Study

  • Kim, Dokyeong;Moon, Sook
    • Journal of dental hygiene science
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    • v.21 no.4
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    • pp.227-232
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    • 2021
  • Background: Cancer-associated fibroblasts (CAFs) are abundant in tumor microenvironments and interact with cancer cells to promote tumor proliferation in oral squamous cell carcinoma (OSCC). Cathepsin D (CTSD) is a soluble lysosomal aspartic endopeptidase involved in tumor proliferation and angiogenesis. In this preliminary study, we observed CTSD expression in OSCC and CAFs, postulating that CTSD might act as a bridge between OSCC and CAFs. Methods: Human epidermal keratinocytes (HEKs), OSCC, and immortalized human normal oral fibroblasts (hTERT-hNOFs) were used in this study. Additionally, we used hTERT-hNOFs transfected with an empty vector, WT (wild-type)-YAP (Yes-associated protein), and YAPS127A (YAP serine 127 to alanine). YAP127A hTERT-hNOFs activated fibroblasts similar to CAFs. To identify CTSD expression between OSCC and CAFs, conditioned medium (CM) was collected from each cell. Protein expression of CTSD was identified by western blotting. Results: To identify the expression of CTSD in fibroblasts stimulated by OSCC, we treated fibroblasts with CM from HEK and OSCC. Results indicated that hTERT-hNOFs with OSCC CM showed a weakly increased expression of CTSD compared to stimulation by HEK CM. This indicates that CAFs, YAPS127 hTRET-hNOFs, overexpress CTSD protein. HEK cells showed no CTSD expression, regardless of treatment with fibroblast CM, whereas OSCC highly expressed CTSD proteins compared with the CTSD expression in HEK cells. We also found that CTSD expression was unaffected by changes in transforming growth factor-β levels. Conclusion: This study proposes that CTSD might have potential as an interacting executor between OSCC and CAFs. Further studies are needed to investigate the role of CTSD in tumor and stromal cells.

Effect of Fermented (Oenanthe stolonifera DC) Extract on the Activity of Enzymes Related to Liver Function of Alcohol-administered Rats and Mice (밭미나리 발효액이 알콜투여 흰쥐의 간기능관련효소활성에 미치는 영향)

  • Whang, Tay-Eak;Lim, Hyun-Ock;Lee, Jae-Wa
    • Korean Journal of Medicinal Crop Science
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    • v.7 no.2
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    • pp.107-114
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    • 1999
  • It has long been recognized that dropwort contains specific funtional subtances for protecting human liver and preventing and curing its diseases, and thus it has been widely utilized in traditional folk remedy. In the present study. fresh of fermented extract of dropwort shoots grown on dryland and fresh extract of those grown on flooded fie1d were fed to the rats suffering from acute, subacute or chronical toxication induced by alcohol administration, and their affects were investigated. Administration of alcohol to rats and mice for 2 days at 5ml of 30% EtOH/kg/day raised total cholesterol and total glyceride which were, however, great1y supressed when alcohol was administered to the laboratory animals previously fed on fresh or fermented extract of dryland dropwort, or fresh extract of flooded field-grown dropwort for 20 days, without significant differences among the extracts. The levels of alanine aminotransferase and aspartate aminotransferase which were raised by alcohol adminstration were also lowered by feeding dropwort extract, among which that of fermented dryland-grown one was more effective than the other two. Chronic alcohol toxication was induced to rats by administering 10% alcohol for 10 months and fermented dropwort extract or tap water was fed to the rats for 5 days. The rats fed on fermented dropwort extract were lower in total cholesterol by 40% and in tota1 glyceride by 60% than the control. Alanine aminotransferase and aspartate aminotransferase in the rats fed on fermented dropwort extract were decreased by 87.2% and 91.7%, respectively, compared to the control, and the rats recovered almost to normal. Activity of alkaline phosphatase, catalase, superoxide dismutase or glutathione peroxidase changed greatly by alcohol administration in the rats suffering from chronic as well as acute toxication. The extract of fermented dry land dropwort significantly lowed the activity of those enzymes, especially, alkaline phosphatase and superoxide dismutase. The present results suggesting the possible medicinal effect of fermented dropwort extract to liver diseases.

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1-Deoxynojirimycin Content and Blood Glucose-Lowering Effect of Silkworm (Bombyx mori) Extract Powder

  • Ryu, Kang-Sun;Lee, Heui-Sam;Kim, Kee-Young;Kim, Mi-Ja;Sung, Gyoo-Byung;Ji, Sang-Deok;Kang, Pil-Don
    • International Journal of Industrial Entomology and Biomaterials
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    • v.27 no.2
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    • pp.237-242
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    • 2013
  • We investigated the 1-deoxynojirimycin (1-DNJ) content of extracts from silkworm larvae at each developmental stage within three silkworm varieties. We also compared the content of the following polyhydroxylated alkaloids in the silkworm extracts: 1-DNJ, fagomine, and 1,4-dideoxy-1,4-imino-d-arabinitol (DAB). In addition, we evaluated the glucose-lowering effects of silkworm extract powder in db/db mice. The 1-DNJ content was the highest in Yeonnokjam $5^{th}$ instar $3^{rd}$ d larvae and Hansaengjam $5^{th}$ instar $3^{rd}$ d larvae, which contained 18.4 mg/100 g dry weight and 18.3 mg/100 g dry weight, respectively. The $5^{th}$ instar $3^{rd}$ d larvae exhibited a higher content of 1-DNJ than that of $5^{th}$ instar $5^{th}$ d larvae among all varieties. The glucose-lowering effects of silkworm extracts and Yeonnokjam powder were tested on db/db mice, and the blood glucose levels were found to decrease significantly in the YR70 group. Silkworm extracts (180 mg/kg, 90 mg/kg, 45 mg/kg, and 22.5 mg/kg) and acarbose (50 mg/kg) were administered orally for 4 wk. Changes in water intake were not statistically significant between control and silkworm extract-treated groups. Compared to the control group, blood glucose levels in the silkworm extract powder-treated group decreased in the 22.5 mg/kg/d group after being administered for 4 wk. This decrease was statistically significant. Furthermore, biochemical changes in the AST(Aspartate aminotransferase), ALT(Alanine aminotransferase), TCHO(Total Cholesterol), TG(Triglyceride), LDL(Low density lipoprotein), and HDL(High density lipoprotein) levels in blood were not observed. However, statistically significant decreases in blood GLU in the 22.5 mg/kg/d group compared to that of the control group occurred. In addition, the epididymal fat weight of the silkworm extract powder-treated group decreased significantly in both the 22.5 mg/kg/d group and 180 mg/kg/d group compared to that of the control group, but there were no statistically significant changes in perirenal fat weight. These results demonstrate that silkworm extracts inhibit changes in blood glucose levels in model diabetic mice.

Analysis of in vitro 2D-COSY on Human Brain Metabolites for Molecular Stereochemistry

  • Kim, Sang-Young;Woo, Dong-Cheol;Bang, Eun-Jung;Kim, Sang-Soo;Lim, Hyang-Sook;Choi, Chi-Bong;Choe, Bo-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.12 no.1
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    • pp.14-25
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    • 2008
  • To investigate the 3-bond connectivity of human brain metabolites by scalar coupling interaction through 2D-correlation spectroscopy (COSY) techniques using high field NMR spectroscopy. All NMR experiments were performed at 298K on Unity Inova 500 or 600 (Varian Inc.) equipped with a triple resonance probe head with z-shield gradient. Human brain metabolites were prepared with 10% $D_2O$. Two dimensional 2D COSY spectra were acquired with 4096 complex data points in $t_2$ and 128 or 256 increments in $t_1$ dimension. The spectral width was 9615.4 Hz and solvent suppression was achieved using presaturation using low power irradiation of the water resonance during 2s of relaxation delay. NMR data were processed using VNMRJ (Varian Instrument) software and all the chemical shifts were referenced to the methyl resonance of N-acetyl aspartate (NAA) peak at 2.0 ppm. Total 10 metabolites such as N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), glutamine (Gln), glutamate (Glu), myo-inositol (Ins), lactate (Lac), taurine (Tau), ${\gamma}$-aminobutyricacid (GABA), alanine (Ala) were included for major target metabolites. Symmetrical 2D-COSY spectra were successfully acquired. Total 14 COSY cross peaks were observed even though there were parallel/orthogonal noisy peaks induced by water suppression. Except for Cr, all of human brain metabolites produced COSY cross peaks. The spectra of NAA methyl proton at 2.02 ppm and Glu methylene proton ($CH_2(3)$) at 2.11 ppm and Gln methylene proton ($CH_2(3)$) at 2.14 ppm were overlapped in the similar resonance frequency between 2.00 ppm and 2.15 ppm. The present study demonstrated that in vitro 2D-COSY represented the 3-bond connectivity of human brain metabolites by scalar coupling interaction. This study could aid in better understanding the interactions between human brain metabolites in vivo 2D-COSY study. Also it would be helpful to determine the molecular stereochemistry in vivo by using two-dimensional MR spectroscopy.

Effects of absorbents on growth performance, blood profiles and liver gene expression in broilers fed diets naturally contaminated with aflatoxin

  • Liu, J.B.;Yan, H.L.;Cao, S.C.;Hu, Y.D.;Zhang, H.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.2
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    • pp.294-304
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    • 2020
  • Objective: The study was conducted to evaluate the effects of the absorbent (a mixture of activated carbon and hydrated sodium calcium aluminosilicate) on growth performance, blood profiles and hepatic genes expression in broilers fed diets naturally contaminated with aflatoxin. Methods: A total of 1,200 one-day-old male chicks were randomly assigned to 6 treatments with 10 replicate cages per treatment. The dietary treatments were as follows: i) control (basal diets); ii) 50% contaminated corn; iii) 100% contaminated corn; iv) control+1% adsorbent; v) 50% contaminated corn+1% absorbent; vi) 100% contaminated corn+1% absorbent. Results: During d 1 to 21, feeding contaminated diets reduced (p<0.05) body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI), but increased (p<0.05) feed-to-gain ratio (F/G). The absorbent supplementation increased (p<0.05) BW, ADG, and ADFI. There were interactions (p<0.05) in BW, ADG, and ADFI between contaminated corn and absorbent. Overall, birds fed 100% contaminated diets had lower (p<0.05) final BW and ADG, but higher (p<0.05) F/G compared to those fed control diets. The absorbent addition increased (p<0.05) serum albumin concentration on d 14 and 28 and total protein (TP) level on d 28, decreased (p<0.05) alanine transaminase activity on d 14 and activities of aspartate aminotransferase and alkaline phosphatase on d 28. Feeding contaminated diets reduced (p<0.05) hepatic TP content on d 28 and 42. The contaminated diets upregulated (p<0.05) expression of interleukin-6, catalase (CAT), and superoxide dismutase (SOD), but downregulated (p<0.05) glutathione S-transferase (GST) expression in liver. The absorbent supplementation increased (p<0.05) interleukin-1β, CAT, SOD, cytochrome P450 1A1 and GST expression in liver. There were interactions (p<0.05) in the expression of hepatic CAT, SOD, and GST between contaminated corn and absorbent. Conclusion: The results suggest that the naturally aflatoxin-contaminated corn depressed growth performance, while the adsorbent could partially attenuate the adverse effects of aflatoxin on growth performance, blood profiles and hepatic genes expression in broilers.