• 제목/요약/키워드: endogenous enzymes

검색결과 112건 처리시간 0.025초

Modification of amylose content of sweetpotato starch by RNAi technique

  • Shimada, Takiko;Otani, Motoyasu;Hamada, Tatsurou;Kim, Sun-Hyung
    • 한국식물생명공학회:학술대회논문집
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    • 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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    • pp.351-355
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    • 2005
  • In the storage roots of sweetpotato (Ipomoea batatas (L.) Lam. cv. Kokei 14), 10 to 20% of starch is essentially unbranched linear amylose and the other major component is branched amylopectin. Amylose is produced by the enzyme GBSSI (granule bound starch synthase I), whereas amylopectin is produced by a concerted action of soluble starch synthase and starch branching enzymes (SBEI and SBEII). We constructed double-stranded RNA (dsRNA) interference vectors of GBSSI and IbSBEII and introduced them into sweetpotato genome via Agrobacterium-mediated gene transformation. The endogenous GBSSI expression was inhibited by dsRNA of GBSSI in 73 % of transgenic plants giving rise to the storage tubers containing amylopectin but not amylose. On the other hand, all sweetpotato plants transformed with dsRNA of IbSBEII contained a larger amount of amylose than the non-transgenic control (up to 25% compared to 10% in the controls). The RNA interference (RNAi) is effectively inhibited the gene expression in thestarch metabolic pathway and modified the characteristics of starch in sweetpotato.

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청아환의 Peroxynitrite 제거 활성 및 기전 (Peroxynitrite Scavenging Activity and its Mechanism of Cheonga-hwan)

  • 김성호;정지천
    • 대한한의학회지
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    • 제23권4호
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    • pp.55-63
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    • 2002
  • Objectives: Peroxynitrite ($ONOO^{-}$), formed from the reaction of superoxide <${\cdot}O_2^{-}$) and nitric oxide (NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA. It has been implicated in diseases such as aging process, Alzheimer's disease, rheumatoid arthritis, cancer and arteriosclerosis. Due to the lack of endogenous enzymes responsible for $ONOO^{-}$ inactivation, developing a specific $ONOO^{-}$ scavenger is of considerable importance. The aim of this study was to evaluate $ONOO^{-}$ scavenging activity and its mechanism in Cheonga-hwan (CAH). Methods: The $ONOO^{-}$ scavenging activity in CAH was assayed by measuring oxidized dihydrorhodamine 123 (DHR 123) by fluorescence. The scavenging efficacy was expressed as $IC_{50}$, showing the concentration of each sample required to cause 50% inhibition of DHR 123 oxidation. In a separate study, the protective effect of CAR on $ONOO^{-}$-induced nitration of bovine serum albumin (BSA) was investigated using immunoassay with a monoclonal anti-nitrotyrosine antibody, and a horseradish peroxidase-conjugated anti-mouse secondary antibody from sheep. Results: CAH showed potent scavenging activities of $ONOO^{-}$, NO and ${\cdot}O_2^{-}$. The data demonstrated that CAH led to decreased $ONOO^{-}$-mediated nitration of tyrosine through electron donation. CAH showed significant inhibition on nitration of bovine serum albumin by $ONOO^{-}$ in a dose-dependent manner. Conclusions: CAH can be developed as an effective peroxynitrite scavenger for the prevention of the $ONOO^{-}$ involved diseases.

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식이성 단백질 함량이 Methanethiol 투여한 흰쥐의 혈청 Xanthine Oxidase 활성에 미치는 영향 (Effect of Dietary Protein on the Serum Xanthine Oxidase Activity in Methanethiol-treated Rats)

  • 윤종국;전태원;임영숙
    • 한국환경보건학회지
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    • 제19권1호
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    • pp.66-70
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    • 1993
  • 저 및 고단백식이로 성장한 흰쥐에 methanethiol 투여시 체중당 간무게 및 혈청 alanine aminotransferase활성의 증가율은 고단백식이군(HP군)보다 저단백식이군(LP군)이 높았으며, 이 때 혈청 보다 xanthine oxidase 활성도는 HP군보다 LP군이 높게 나타났다. 또한 혈청 중 요산함량 역시 HP군보다 LP군에서 높게 나타났으며, 간조직의 uricase 활성은 LP군이 HP군보다 높게 나타났다. 따라서 LP군이 HP군보다, methanethiol 투여로 인한 혈청 xanthine oxidase 활성이 높게 나타남은 식이중 단백함량을 낮출 때 methanethiol 에 의한 간독성이 심하게 나타나기 때문이며, 또한 단백영양 부족시 methanethiol 의 폭로가 고뇨산혈증을 유도함을 시사해 주고 있다.

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인삼부위별 및 건조온도에 따른 유리당의 함량변화 (Free sugar distribution in ginseng plant and change of it's content in the root with dehydration)

  • 김해중;조재선
    • Journal of Ginseng Research
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    • 제7권1호
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    • pp.44-50
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    • 1983
  • This study was conducted to investigate distribution of free sugas in the ginseng plant and change of free sugar content in dried ginseng with various drying conditions. The results obtained are as follows: 1. The total free sugar content is about 1% in the root and about 2% in the upland portions. Sucrose which accounts 80% in those free sugars, is 0.91% in main body 0.90% in raw ginseng, 0.74% in latheral root, 0.67% in head, 0.57% in skin, 0.64% in leaves, and 0.35% in steins. 2. Sucrose content is 3.3~4.6% in the ginseng root dried at temperature of 3$0^{\circ}C$ and 0.5 ~ 1% in the root dried it at temperature of 50-9$0^{\circ}C$. 3. Maltose was not present in fresh ginseng or dried ginseng which was dried under the t, but it was produced dried at the temperature above 5$0^{\circ}C$, it was 0.5% at 5$0^{\circ}C$, 1.49 %. at 7$0^{\circ}C$, and 4.03% at 9$0^{\circ}C$, respectively. This sugar Height be produced by endogenous saccharifying enzymes.

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Mechanisms involved in adenosine pharmacological preconditioning-induced cardioprotection

  • Singh, Lovedeep;Kulshrestha, Ritu;Singh, Nirmal;Jaggi, Amteshwar Singh
    • The Korean Journal of Physiology and Pharmacology
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    • 제22권3호
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    • pp.225-234
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    • 2018
  • Adenosine is a naturally occurring breakdown product of adenosine triphosphate and plays an important role in different physiological and pathological conditions. Adenosine also serves as an important trigger in ischemic and remote preconditioning and its release may impart cardioprotection. Exogenous administration of adenosine in the form of adenosine preconditioning may also protect heart from ischemia-reperfusion injury. Endogenous release of adenosine during ischemic/remote preconditioning or exogenous adenosine during pharmacological preconditioning activates adenosine receptors to activate plethora of mechanisms, which either independently or in association with one another may confer cardioprotection during ischemia-reperfusion injury. These mechanisms include activation of $K_{ATP}$ channels, an increase in the levels of antioxidant enzymes, functional interaction with opioid receptors; increase in nitric oxide production; decrease in inflammation; activation of transient receptor potential vanilloid (TRPV) channels; activation of kinases such as protein kinase B (Akt), protein kinase C, tyrosine kinase, mitogen activated protein (MAP) kinases such as ERK 1/2, p38 MAP kinases and MAP kinase kinase (MEK 1) MMP. The present review discusses the role and mechanisms involved in adenosine preconditioning-induced cardioprotection.

비타민 E가 쥐간 세포의 암화과정에서 태반형 Glutathione S-transferase(GST-P) 양성 병소와 항산화요소계에 미치는 영향 (Suppressive Effects of Vitamin E on the Induction of Placental Glutathione S-transferase(GST-P) Positive foci and Antioxidant Enzyme Activity in Rat Hepatocarcinogenesis)

  • 최혜미
    • Journal of Nutrition and Health
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    • 제30권7호
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    • pp.803-812
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    • 1997
  • The influences of dietary supplements of vitamin E on hepatocellular chemical carcinogenesis have been studied, Placental glutathione S-transferase(GST-P) positive foci area, antioxidant enzymes(superoxide dismutase(SOD), catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase(GST)), glucose 6-phosphatase(G6Pase) activities, and lipid peroxidation of mecrosomes(thiobarbituric acid reactive substances(TBARS) contents) were investigated. For is purpose , we used the murine chemical hepatocardinogenic procedure induced by modified Ito model, which consists of 200mg/kg body weight diethylinitrosamine (DEN) injection, 0.01% 2-acethlaminoflurene(2-AAF) feeding for 6 weeks, and partial hepatectomy on week 3. Weanling Sprague-Dawley male rats were fed pulverized Purina rat chow with 15, 000IU/kg diet vitamin E from initiation or promotion stages. We found that vitamin E supplement decreased the area of GST-P positive foci. Catalase, glutathione peroxidase, glutathione reductase. GST activities, and TBARS contents were decreased. On the other hand G6Pase activities were increased by vitamin E supplement. It seemed that vitamin E supplements helped endogenous defense systems against carcinogenesis by decreasing TBARS contents, $H_2O$$_2$ and organic peroxides. So, vitamin E seemed to protect cell from free radical damage in carcinogenesis. Anticarcinogenic effects of vitamin E were more effective at intiation that at promotion stage. These results suggest that vitamin E has suppressive effects on hepatocellular chemical carcinogenesis, probably through antioxidant effects against TBARS contents $H_2O$$_2$ and orgainc peroxides.

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Acute and Chronic Effects of Nanoplastics on the Water Flea Moina macrocopa

  • Md. Niamul Haque;Jaehee Kim;Jae-Sung Rhee
    • 한국해양생명과학회지
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    • 제8권1호
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    • pp.78-86
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    • 2023
  • Here, upon acute (96 h) and chronic (14 days) exposure, ingestion of polystyrene NPs (100 nm) and physiological, biochemical, and cholinergic modulations were analyzed in the water flea Moina macrocopa exposed to different concentrations (0.001, 0.01, 0.1, 1, 5, 10, 50, 100, and 500 ㎍ l-1). Exposed NPs were observed in the internal organs (e.g., digestive tract and foregut) of the water flea. Chronic exposure to the relatively high concentrations resulted in significant decreases in survival, body length, and the total number of molts, whereas reproduction parameter was not affected. Significant increase in oxidative stress biomarker (malondialdehyde) and decrease in the intracellular content of endogenous antioxidant (glutathione) and enzymatic activity of antioxidant enzymes (glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase, and glutathione S-transferase) were detected in response to relatively high concentrations of NPs. Transcriptional expression of the hsp70 gene was increased in response to relatively high concentrations of NPs, whereas acetylcholinesterase activity was lowered by the same concentrations of NPs. Taken together, NPs exposure would be a significant modulator on physiological and biochemical metabolism of water flea.

Ga-mi-Yuk-Mi-Jihwang-Tang Ameliorates LPS-injected acute Liver Injury via Regulation of Sirtuin6 in Inflammasome Triggered-pyroptosis Using Mice Model

  • 임수아;조명래;김태수;성수희;김보람;최경민;정진우
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2022년도 추계학술대회
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    • pp.114-114
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    • 2022
  • Excessive endogenous endotoxin, especially lipopolysaccharide (LPS) reflux from gastrointestinal (GI) tract to the liver tissue is one of the most serious reasons of severe and acute liver injury which is mainly mediated by Kupffer cell activations. However, there is no clear molecular clues to explain the exact pathophysiological mechanism and effective drugs available till nowadays. We aimed to comprehend the pathophysiological features of LPS-induced liver injury and evaluate the efficacies of potential therapeutic drug, Ga-mi-Yuk-Mi-Jihwang-Tang (GYM), which is composed of herbal plants. GYM remarkably caused to normalize hepatic inflammation and oxidations against LPS-induced liver injury by evidence of serum liver enzymes, histopathological analysis, both hepatic protein and gene expression levels of pro-inflammatory cytokines, nitric oxide levels, and hepatic tissue levels of reactive oxygen species (ROS) levels, malondialdehyde (MDA), and 4-hydroxyneoneal, respectively. To assess molecular events in the hepatic tissue, we further found hepatic Sirtuin6 (Sirt6) levels were considerably depleted by LPS injection with aberrant alterations of Nrf2/HO-1 signaling pathways, whereas administration with GYM notably exerted to normalize these abnormalities. Our results exhibited that GYM would be one of target drug to diminish hepatic inflammation as well as oxidative stress by regulation of hepatic Sirt6 levels.

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HepaRG 세포를 이용한 Bosentan 약물의 CYP450 효소활성 측정 (Measurement of CYP450 Enzymes Activity of Bosentan in HepaRG Cell)

  • 한경문;정정아;신지순;차혜진;배영지;김현욱;김영훈;성원근;강호일
    • 약학회지
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    • 제58권4호
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    • pp.255-261
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    • 2014
  • Poly-pharmacy has been on the rise because of aging of population and chronic disease. Most of drug metabolism happens in the liver by CYP isozymes and the metabolism by CYP450 enzymes. The Cytochrome P450 (CYP) is a superfamily of enzymes that catalyzes the oxidations of many endogenous and exogenous compounds. Primary human Hepatocytes (HH) are considered as the gold standard model for In vitro drug interaction studies. However, there are several limitations (cost, limited life span) for using HH cells. HepaRG cells are being used as a possible alternative. HepaRG cells were cultured in William E medium containing the positive control inducers (1A2: 10, 25, 50 ${\mu}M$ omeprazole, 2C9 and 2C19: 10 ${\mu}M$ rifampin, 3A4: 10, 25, 50 ${\mu}M$ rifampin) at $37^{\circ}C$, 5 % $CO_2$ in a humidified atmosphere. This study was to evaluate the induction of CYP isozymes (1A2, 2C9, 2C19 and 3A4) using LC-MS/MS. We evaluated the potential induction ability of Bosentan, as a drug of pulmonary artery hypertension, in HepaRG cells. For reference, dose of the Bosentan is determined to the basis of the $C_{max}$ (835 mg/ml) value. The enzyme activity demonstrated that CYP2C9 and 3A4 were induced up to 20 times by Bosentan. Like as In vivo, the enzyme activity of CYP2C9 and CYP3A4 is significantly induced in a dose-dependent by Bosentan.

소 CYP26A1 유전자 프로모터의 molecular cloning 및 특성 (Molecular Cloning and Characterization of Bovine CYP26A1 Promoter)

  • 곽인석
    • 생명과학회지
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    • 제26권1호
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    • pp.42-49
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    • 2016
  • 레티노산(RA)는 많은 유형의 세포에서 성장 및 발달에 중요한 역할을 수행하며 생체 활성화에 적합한 RA의 농도는 CYP26A1 등 여러 가지 효소에 의해 조절된다. CYP26A1의 발현은 RA에 의해서 조절되며 CYP26A1는 RA에 반응하는 유전자 중 하나이다. CYP26A1 유전자 클로닝은 여러 동물에서 보고되어 있지만, 소에서 CYP26A1 유전자의 클로닝은 아직 보고되지 않았다. 소로부터 CYP26A1의 프로모터 부위를 중합효소 연쇄반응을 이용하여 클로닝 한 후 다른 동물과 염기 서열 비교분석 결과 RARE DR-5 (ttggg)의 존재를 확인하였고, DR-5의 염기서열은 분석한 종 에서 완전히 일치하였다. DR-5 motif를 함유한 소의 CYP26A1 프로모터 부위를luciferase리포터 유전자에 결합한 후 transient transfection에 의해 promoter 발현을 분석하였다. 폐 유래 세포주인 MTCC 세포에서 CYP26A1 promoter의 발현은 ATRA의 처리에 의하여 촉진되었다. CYP26A1 유전자의 발현은 ATRA 의존적으로 RAR-α 및 RAR-β에 의하여 현저하게 촉진되었다. 그러나 RAR-γ나 RXR-γ는 CYP26A1 발현에 별다른 영향을 미치지는 않았다. 또한 MTCC 세포주가 생산하는 내인성 CYP26A1 유전자 발현을 Q-RT-PCR로 분석한 결과 1-2일간의 ATRA 처리에 의해서는 현저한 영향을 받지 않으나, 3일 동안 ATRA를 처리한 샘플에서는 CYP26A1의 발현이 현저하게 감소하였다. 결론적으로, 소의 CYP26A1유전자의 프로모터 부위에 존재하는 DR-5 RARE는 RAR-α 및 RAR-β의 결합부위로 작용하여 MTCC 세포에서 CYP26A1 유전자 발현 조절과 RA signal의 조절에 관여하는 것을 확인하였다.