• Title/Summary/Keyword: Enzyme regulation

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Purification and Characterization of stu I Endomuclease from Streptomyces Tubercidicus (Streptomyces tubercidicus에 존재하는 stu I endonuclease의 정제와 특징)

  • 김기태;정미영;유욱준
    • Korean Journal of Microbiology
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    • v.25 no.3
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    • pp.180-183
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    • 1987
  • Stu I, type II restriction endonuclease, has been purified to homogeneity from Streptomyces tubercidicus (ATCC 25502), and its catalytic properties have been studied. For the purification of Stu I endonuclease free of nonspecific nucleases, DEAE-Sephadex (A-50), QAE-Sephadex (A-50) and Heparin-agarose column chromatography have been performed after ammonium sulfate fractionation of the crude extract. The enzyme was further purified by gel filtration using Sephadex G-100 column to obtain homogeneous form of protein. The single polypeptide species of Stu I endonuclease has a subunit molecular weight of 34,000 $\pm$ 1,000 daltons as judged by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Stu I endonuclease requires $Mg^{2+}$ ion for its activity and is maximally active at neutral pH (7.0-8.0) in the absence of NaCl.

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Study on the Protective Effect of Corni Fructus against Free Radical Mediated Liver Damage (산수유의 유리자유기에 의한 간손상 보호효과)

  • Ha, Ki-Tae;Kim, Young-Mi;Kim, Cheorl-Ho;Kim, Dong-Wook;Choi, Dall-Yeong;Kim, June-Ki
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.6
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    • pp.1415-1423
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    • 2007
  • Carbon tetrachloride ($CCl_4$)-induced liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Alternations in the activity of cytochrome P450 enzymes affect the susceptibility to hepatic injury from $CCl_4$. In this study, we evaluated the potential protective activity of the traditional Korean medicinal herb, Corni fructus (CF), against an experimental model of hepatotoxicity induced by $CCl_4$. The CF exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Sprague-Dawley (SD) rats, as measured by GOT, GPT, ALP and histological observation. The CF also showed significant decrease of malodialdehyde (MDA) and increase of glutathion (GSH), catalase activity in rat liver homogenate. In addition, the expression of CYP2E1, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, was significantly decreased in the liver of CF treated SD rats. But $CCl_4$ and CF has no significant effect on 1A1 and 3A1 isoform of cytochrome P450. Based on these findings, it is suggested that hepatoprotective effects of CF possibly related to antioxidative effects and regulation of CYP2E1 expression.

Increased Sensitivity to Chloramphenicol by Inactivation of manB in Streptomyces coelicolor

  • Rajesh, Thangamani;Song, Eunjung;Lee, Bo-Rahm;Park, Sung-Hee;Jeon, Jong-Min;Kim, Eunjung;Sung, Changmin;Lee, Jae-Hun;Yoo, Dongwon;Park, Hyung-Yeon;Kim, Yun-Gon;Kim, Byung-Gee;Yang, Yung-Hun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.10
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    • pp.1324-1329
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    • 2012
  • Phosphomannomutase (ManB) is involved in the biosynthesis of GDP-mannose, which is vital for numerous processes such as synthesis of carbohydrates, production of alginates and ascorbic acid, and post-translational modification of proteins. Here, we discovered that a deletion mutant of manB (BG101) in Streptomyces coelicolor (S. coelicolor) showed higher sensitivity to bacteriostatic chloramphenicol (CM) than the wild-type strain (M145), along with decreased production of CM metabolites. Deletion of manB also decreased the mRNA expression level of drug efflux pumps (i.e., cmlR1 and cmlR2) in S. coelicolor, resulting in increased sensitivity to CM. This is the first report on changes in antibiotic sensitivity to CM by deletion of one glycolysis-related enzyme in S. coelicolor, and the results suggest different approaches for studying the antibiotic-resistant mechanism and its regulation.

Apigenin Inhibits Tumor Necrosis Factor-α-Induced Production and Gene Expression of Mucin through Regulating Nuclear Factor-Kappa B Signaling Pathway in Airway Epithelial Cells

  • Seo, Hyo-Seok;Sikder, Mohamed Asaduzzaman;Lee, Hyun Jae;Ryu, Jiho;Lee, Choong Jae
    • Biomolecules & Therapeutics
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    • v.22 no.6
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    • pp.525-531
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    • 2014
  • In the present study, we investigated whether apigenin significantly affects tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced production and gene expression of MUC5AC mucin in airway epithelial cells. Confluent NCI-H292 cells were pretreated with apigenin for 30 min and then stimulated with TNF-${\alpha}$ for 24 h or the indicated periods. The MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription - polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Apigenin significantly inhibited MUC5AC mucin production and down-regulated MUC5AC gene expression induced by TNF-${\alpha}$ in NCI-H292 cells. To elucidate the action mechanism of apigenin, effect of apigenin on TNF-${\alpha}$-induced nuclear factor kappa B (NF-${\kappa}B$) signaling pathway was also investigated by western blot analysis. Apigenin inhibited NF-${\kappa}B$ activation induced by TNF-${\alpha}$. Inhibition of inhibitory kappa B kinase (IKK) by apigenin led to the suppression of inhibitory kappa B alpha ($I{\kappa}B{\alpha}$) phosphorylation and degradation, p65 nuclear translocation. This, in turn, led to the down-regulation of MUC5AC protein production in NCI-H292 cells. Apigenin also has an influence on upstream signaling of IKK because it inhibited the expression of adaptor protein, receptor interacting protein 1 (RIP1). These results suggest that apigenin can regulate the production and gene expression of mucin through regulating NF-${\kappa}B$ signaling pathway in airway epithelial cells.

Ginsenoside Rg3 attenuates skin disorders via down-regulation of MDM2/HIF1α signaling pathway

  • Han, Na-Ra;Ko, Seong-Gyu;Moon, Phil-Dong;Park, Hi-Joon
    • Journal of Ginseng Research
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    • v.45 no.5
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    • pp.610-616
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    • 2021
  • Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for inflammatory responses. Ginsenoside Rg3 (Rg3) which is an active ingredient of Panax ginseng Meyer (Araliaceae) is known to possess various therapeutic effects. However, a modulatory effect of Rg3 on TSLP expression in the inflammatory responses remains poorly understood. Methods: We investigated antiinflammatory effects of Rg3 on an in vitro model using HMC-1 cells stimulated by PMA plus calcium ionophore (PMACI), as well as an in vivo model using PMA-induced mouse ear edema. TSLP and vascular endothelial growth factor (VEGF) levels were detected using enzyme-linked immunosorbent assay or real-time PCR analysis. Murine double minute 2 (MDM2) and hypoxia-inducible factor 1α (HIF1α) expression levels were detected using Western blot analysis. Results: Rg3 treatment restrained the production and mRNA expression levels of TSLP and VEGF in activated HMC-1 cells. Rg3 down-regulated the MDM2 expression level increased by PMACI stimulation. The HIF1α expression level was also reduced by Rg3 in activated HMC-1 cells. In addition, Rg3-administered mice showed the decreased redness and ear thickness in PMA-irritated ear edema. Rg3 inhibited the TSLP and VEGF levels in the serum and ear tissue homogenate. Moreover, the MDM2 and HIF1α expression levels in the ear tissue homogenate were suppressed by Rg3. Conclusion: Taken together, the current study identifies new mechanistic evidence about MDM2/HIF1α pathway in the antiinflammatory effect of Rg3, providing a new effective therapeutic strategy for the treatment of skin inflammatory diseases.

Effect of Salvia miltiorrhiza aerial parts on growth performance, nutrient digestibility, and digestive enzymes in rabbits

  • Wang, Jiajia;Luo, Yiran;Li, Pei;Zhang, Feike;Liu, Ning
    • Animal Bioscience
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    • v.34 no.12
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    • pp.1981-1986
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    • 2021
  • Objective: This study aimed to investigate the effect of Salvia miltiorrhiza (S.m.) aerial parts as an alternative ingredient on growth performance, nutrient digestibility, and digestive enzymes in growing rabbits. Methods: Treatments included five tested diets: a control (basal diet), antibiotic (basal diet+enramycin at 5 mg/kg), and S.m. aerial parts powder added at 3.0%, 6.0%, and 9.0% of feed using 300 growing rabbits. Results: The diets with S.m. aerial parts addition at 9.0% decreased (p<0.05) feed/gain compared to the control, but there were no differences in feed intake and body weight gain. In contrast with the control, the addition of antibiotic increased (p<0.05) digestibility of dry matter, crude protein, energy, fiber, and ash. The herb addition did not cause differences in the digestibility of most nutrients compared to the antibiotic, but fiber digestibility of the herb at 6.0% and 9.0% was lower (p<0.05) than that of the antibiotic. Moreover, the antibiotic and the herb also similarly increased (p<0.05) the activities of duodenal α-amylase, maltase, lipase, and trypsin, compared to the control, and the herb at 6.0% and 9.0% showed a greater (p<0.05) activity of elastase than the dose 3.0%. Conclusion: The obtained data indicate that S.m. aerial parts can be a potential forage in rabbit's diet at 9.0% with a beneficial regulation on nutrition and digestion.

Molecular Cloning, Protein Expression, and Regulatory Mechanisms of the Chitinase Gene from Spodoptera littoralis Nucleopolyhedrovirus

  • Yasser, Norhan;Salem, Reda;Alkhazindar, Maha;Abdelhamid, Ismail A.;Ghozlan, Said A.S.;Elmenofy, Wael
    • Microbiology and Biotechnology Letters
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    • v.49 no.3
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    • pp.305-315
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    • 2021
  • The cotton leafworm, Spodoptera littoralis, is a major pest in Egypt and many countries worldwide, and causes heavy economic losses. As a result, management measures to control the spread of the worm are required. S. littoralis nucleopolyhedrovirus (SpliNPV) is one of the most promising bioagents for the efficient control of insect pests. In this study, a chitinase gene (chitA) of a 1.8 kb DNA fragment was cloned and fully characterized from SpliNPV-EG1, an Egyptian isolate. A sequence of 601 amino acids was deduced when the gene was completely sequenced with a predicted molecular mass of 67 kDa for the preprotein. Transcriptional analyses using reverse transcription polymerase chain reaction (RT-PCR) revealed that chitA transcripts were detected first at 12 h post infection (hpi) and remained detectable until 168 hpi, suggesting their transcriptional regulation from a putative late promoter motif. In addition, quantitative analysis using quantitative RT-PCR showed a steady increase of 7.86-fold at 12 hpi in chitA transcription levels, which increased up to 71.4-fold at 120 hpi. An approximately 50 kDa protein fragment with chitinolytic activity was purified from ChitA-induced bacterial culture and detected by western blotting with an anti-recombinant SpliNPV chitinase antibody. Moreover, purification of the expressed ChitA recombinant protein showed in vitro growth inhibition of two different fungi species, Fusarium solani and F. oxysporum, confirming that the enzyme assembly and activity was correct. The results supported the potential role and application of the SpliNPV-ChitA protein as a synergistic agent in agricultural fungal and pest control programs.

Aqueous extract of Petasites japonicus leaves promotes osteoblast differentiation via up-regulation of Runx2 and Osterix in MC3T3-E1 cells

  • Kim, Eun Ji;Jung, Jae In;Jeon, Young Eun;Lee, Hyun Sook
    • Nutrition Research and Practice
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    • v.15 no.5
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    • pp.579-590
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    • 2021
  • BACKGROUND/OBJECTIVES: Petasites japonicus Maxim (P. japonicus) has been used as an edible and medicinal plant and contains many bioactive compounds. The purpose of this study is to investigate the effect of P. japonicus on osteogenesis. MATERIALS/METHODS: The leaves and stems of P. japonicus were separated and extracted with hot water or ethanol, respectively. The total phenolic compound and total polyphenol contents of each extract were measured, and alkaline phosphatase (ALP) activity of each extract was evaluated to determine their effect on bone metabolism. To investigate the effect on osteoblast differentiation of the aqueous extract of P. japonicus leaves (AL), which produced the highest ALP activity among the tested extracts, collagen content was measured using the Sirius Red staining method, mineralization using the Alizarin Red S staining method, and osteocalcin production through enzyme-linked immunosorbent assay analysis. Also, real-time reverse transcription polymerase chain reaction was performed to investigate the mRNA expression levels of Runt-related transcriptional factor 2 (Runx2) and Osterix. RESULTS: Among the 4 P. japonicus extracts, AL had the highest values in all of the following measures: total phenolic compounds, total polyphenols, and ALP activity, which is a major biomarker of osteoblast differentiation. The AL-treated MC3T3-E1 cells showed significant increases in induced osteoblast differentiation, collagen synthesis, mineralization, and osteocalcin production. In addition, mRNA expressions of Runx2 and Osterix, transcription factors that regulate osteoblast differentiation, were significantly increased. CONCLUSIONS: These results suggest that AL can regulate osteoblasts differentiation, at least in part through Runx2 and Osterix. Therefore, it is highly likely that P. japonicus will be useful as an alternate therapeutic for the prevention and treatment of osteoporosis.

Hesperetin suppresses LPS/high glucose-induced inflammatory responses via TLR/MyD88/NF-κB signaling pathways in THP-1 cells

  • Lee, Aeri;Gu, HyunJi;Gwon, Min-Hee;Yun, Jung-Mi
    • Nutrition Research and Practice
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    • v.15 no.5
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    • pp.591-603
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    • 2021
  • BACKGROUND/OBJECTIVES: Unregulated inflammatory responses caused by hyperglycemia may induce diabetes complications. Hesperetin, a bioflavonoid, is a glycoside in citrus fruits and is known to have antioxidant and anticarcinogenic properties. However, the effect of inflammation on the diabetic environment has not been reported to date. In this study, we investigated the effect of hesperetin on proinflammatory cytokine secretion and its underlying mechanistic regulation in THP-1 macrophages with co-treatment LPS and hyperglycemic conditions. MATERIALS/METHODS: THP-1 cells differentiated by PMA (1 µM) were cultured for 48 h in the presence or absence of hesperetin under normoglycemic (5.5 mM/L glucose) or hyperglycemic (25 mM/L glucose) conditions and then treated with LPS (100 ng/mL) for 6 h before harvesting. Inflammation-related proteins and mRNA levels were evaluated by enzyme-linked immunosorbent assay, western blot, and quantitative polymerase chain reaction analyses. RESULTS: Hesperetin (0-100 µM, 48 h) treatment did not affect cell viability. The tumor necrosis factor-α and interleukin-6 levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions, and these increases were decreased by hesperetin treatment. The TLR2/4 and MyD88 activity levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions; however, hesperetin treatment inhibited the TLR2/4 and MyD88 activity increases. In addition, nuclear factor-κB (NF-κB) and Acetyl-NF-κB levels increased in response to treatment with LPS under hyperglycemic conditions compared to normoglycemic conditions, but those levels were decreased when treated with hesperetin. SIRT3 and SIRT6 expressions were increased by hesperetin treatment. CONCLUSIONS: Our results suggest that hesperetin may be a potential agent for suppressing inflammation in diabetes.

Anti-Inflammatory Effect of the Extracts from Leaves and Stems of Thymus quinquecistatus var. japonica (H.Hara) (섬백리향 잎과 줄기 추출물의 항염 활성에 관한 세포생물학적 연구)

  • Lee, Sun-Mi;Baek, Jeong-In
    • The Korea Journal of Herbology
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    • v.36 no.5
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    • pp.125-133
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    • 2021
  • Objectives : Thymus quinquecistatus var. japonica (H.Hara) is a member of the genus Thymus of perennial aromatic herb, and it's designated as a natural monument of South Korea. It has traditionally been known to have protective or therapeutic effects on various human disease including cerebrovascular and neurological disease. Recently it was suggested that essential oil extracted from thyme has anti-fungal and anti-bacterial effect. The aim of this study is to investigate anti-inflammatory effect of Thymus quinquecistatus var. japonica in Raw 264.7 macrophage cell line. Methods : The cytotoxic effects of water and 70% ethanol extracts from Thymus quinquecistatus var. japonica, was tested using MTT assay. Inhibitory effects of the extracts to nitric oxide production and mRNA expression of inflammatory cytokines were examined by RT-PCR. Also, MitoSOX-red assay and JC-1 assay were performed to determine if the extracts can inhibit mitochondrial ROS accumulation and maintain mitochondrial membrane potential. Results : In LPS-induced inflammatory response, the extracts efficiently reduced nitric oxide NO production through inhibiting mRNA expression of iNOS enzyme. In addition, expression of the proinflammatory cytokines, IL-1𝛽 and IL-6, was also down-regulated by the extract treatments. Excessive accumulation of mitochondrial ROS induced by LPS was inhibited in the extract treated cells, which finally protected mitochondrial membrane potential. Conclusions : These results showed that water and 70% ethanol extracts from Thymus quinquecistatus var. japonica have anti-inflammatory effect through down regulation of IL-1𝛽, IL-6, and iNOS, and also have antioxidative effect against mitochondrial ROS accumulation that promote inflammatory response.