• Title/Summary/Keyword: enzyme regulation

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Effects of phenylephrine-induced PKC activation on Mg2+ release in guinea pig heart and isolated ventricular myocytes (기니픽 심장과 심근세포에서 Phenylephrine에 의한 PKC 활성화가 Mg2+ 유리에 미치는 영향)

  • Chang, Sung-eun;Kang, Hyung-sub;Kim, Jin-sang
    • Korean Journal of Veterinary Research
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    • v.38 no.1
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    • pp.29-42
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    • 1998
  • $Mg^{2+}$ is one of the most abundant divalent cations in mammalian body(0.2~1.0mM) and the important physiological roles are : first, the cofactor of many enzyme activities, second, the regulator of glycolysis and DNA synthesis, third, the important role of bioenergetics by regulating of phosphorylation, fourth, the influence of cardiac metabolism and function. In this work we have investigated the regulation of the $Mg^{2+}$ induced by ${\alpha}_1-adrenoceptor$ stimulation in perfused guinea pig hearts and isolated myocytes. The $Mg^{2+}$ content of the perfusate or the supernatant was measured by atomic absorbance spectrophotometry. The elimination of $Mg^{2+}$ in the medium increased the force of contraction of right ventricular papillary muscles, and the left ventricular pressure. Phenylephrine also enhanced the force of contraction in the presence of $Mg^{2+}-free$ medium. ${\alpha}_1-Agonists$ such as phenylephrine and methoxamine were found to induce $Mg^{2+}$ efflux in both perfused hearts and myocytes. These effects were blocked by prazosin, an ${\alpha}_1-adrenoceptor$ antagonist. The $Mg^{2+}$ influx could also be induced by phenylephrine and R59022, a diacylglycerol kinase inhibitor. In the presence of protein kinase C(PKC) inhibitors, phenylephrine produced an increase in $Mg^{2+}$ efflux from perfused hearts. Furthermore, $Mg^{2+}$ efflux by phenylephrine was amplified by phorbol 12-myristate 13-acetate(PMA). This enhancement of $Mg^{2+}$ efflux by PMA was blocked by prazosin in perfused hearts. By contrast, the $Mg^{2+}$ influx could be induced by verapamil, nifedipine, ryanodine in perfused hearts, but not in myocytes. $W^7$, a $Ca^{2+}$/calmodulin antagonist, completely blocked the phenylephrine-induced $Mg^{2+}$ efflux in perfused hearts. In conclusion, $Mg^{2+}$ is responsible for the cardiac activity associated with ${\alpha}_1-adrenoceptor$ stimulation. The mobilization of $Mg^{2+}$ is decreased or increased by ${\alpha}_1-adrenoceptor$ stimulation in guinea pig hearts. These responses may be related specifically to the respective pathways of signal transduction. A decrease in $Mg^{2+}$ efflux by ${\alpha}_1-adrenoceptor$ stimulation in hearts can be through PKC dependent and intracellular $Ca^{2+}$ levels.

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Adenoviral-Mediated Ref-1 Overexpression Potentiates NO Production in Bradykinin-Stimulated Endothelial Cells (Bradykinin으로 자극한 혈관내피세포에서 Ref-1의 세포내 과발현에 의한 NO 생성 증진 효과에 대한 연구)

  • Song, Ju-Dong;Kim, Kang-Mi;Lee, Sang-Kwon;Kim, Jong-Min;Park, Young-Chul
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.905-909
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    • 2007
  • The dual-function protein redox factor-1 (Ref-1) is essential for base excision repair of oxidatively damaged DNA and also governs the activation of many redox-sensitive transcription factors. We examined the role of Ref-1 in regulation of nitric oxide (NO) synthesis employing adenoviral-mediatedoverexpression of Ref-1 in bradykinin-stimulated endothelial cells. Intracellular NO was detected with the NO-sensitive fluorophore DAF-2. Overexpression of Ref-1 potentiates bradykinin-stimulated NO production in endothelial cells. And, cells ifected with AdRef-1 showed higher fluorescence intensity compared with uninfected or AdD1312-infected cells. In parallel with this, over expression of Ref-1 also stimulated endothelial NO synthase (eNOS) enzyme activity, compared with unifected or AdD1312-infected cells, in bradykinin-stimulated cells as well as in unstimulated cells. These results suggest that Ref-1 implicates in endothelium-dependent vasorelaxation resulting from NO production in vascular system.

Inhibition of Cyclooxygenase-2 Activity and Prostaglandin E2 Production through Down-regulation of NF-κB Activity by the Extracts of Fermented Beans (발효 콩의 NF-κB 활성 억제를 통한 cyclooxgenase-2 활성과 prostaglandin E2 생성 억제)

  • Lee, Hye-Hyeon;Park, Cheol;Kim, Min-Jeong;Seo, Min-Jeong;Choi, Sung-Hyun;Jeong, Yong-Kee;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.20 no.3
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    • pp.388-395
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    • 2010
  • Cyclooxygenase (COX)-2 is generally known as an inducible enzyme, and it produces arachidonic acid to prostaglandin $E_2$ ($PGE_2$), which has been demonstrated to play a critical role in inflammation. In the present study, we investigated the effects of the extracts of fermented beans including soybean (FS), black agabean (FBA) and yellow agabean (FYA), on the expression of COXs and production of $PGE_2$ in U937 human promonocytic cells. Treatment of phorbol 12-myristate 13-acetate (PMA) significantly induced pro-inflammatory mediators such as COX-2 expression and $PGE_2$ production, whereas the levels of COX-1 remained unchanged. However, pre-treatment with FS, FBA and FYA significantly decreased PMA-induced COX-2 protein as well as mRNA, which is associated with inhibition of $PGE_2$ production. Moreover, FS, FBA and FYA markedly prevented the increase of nuclear translocation of nuclear factor kappa B (NF-${\kappa}B$) p65 by PMA. Our data indicate that the extracts of fermented beans exhibits anti-inflammatory properties by suppressing the transcription of pro-inflammatory cytokine genes through the NF-${\kappa}B$ signaling pathway.

Cloning and Structural Analysis of bfmo Operon in Methylophaga aminosulfidovorans SK1 (Methylophaga aminosulfidovorans SKI bfmo 오페론의 클로닝 및 구조 분석)

  • Lim Hyun Sook;Goo Jae Whan;Kim Lee Hyun;Kim Si Wouk;Cho Eun Hee
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.1-7
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    • 2005
  • Methylophaga aminosulfidovorans SK1 (KCTC 10323 BP) can utilize trimethylamine as a sole carbon, nitrogen, and energy source. The bacterial flavin-containing monooxygenase (bFMO) gene was identified in the strain and the recombinant enzyme expressed in E. coli oxidized trimethylamine. To study the function and regulation of the bfmo, over 8,000 nucleotide sequences of the neighboring regions including the bfmo were determined. Three open reading frames proceeding to the bfmo gene encoded analogues to highly conserved nitrate/nitrite sensing two-component system regulators and a methyl accepting protein. Two small open reading frames just downstream of the bfmo gene showed no similar proteins of known functions but the sequences were conserved among other bacteria. Reverse transcription-polymerase chain reaction analysis showed that the six putative genes consisted of three transcription units. The three regulatory genes located upstream of the bfmo gene formed two separate transcription units. The bfmo and the two downstream genes were transcribed from a single promoter.

Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats

  • Lu, Huan-Jun;Li, Mei-Han;Li, Mei-Zhi;Park, Sang Eon;Kim, Min Sun;Jin, Yuan-Zhe;Park, Byung Rim
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.5
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    • pp.427-434
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    • 2015
  • Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.

Anti-Oxidative and Anti-Inflammatory Effects of Malus huphensis, Ophiorrhiza cantonensis, and Psychotria rubra Ethanol Extracts (Malus huphensis, Ophiorrhiza cantonensis, Psychotria rubra 에탄올 추출물의 항산화 및 항염증 활성)

  • Jin, Kyong-Suk;Kwon, Hyun Ju;Kim, Byung Woo
    • Microbiology and Biotechnology Letters
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    • v.42 no.3
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    • pp.275-284
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    • 2014
  • This study was orchestrated with the purpose of uncovering new nutraceutical resources possessing biological activities in the plant kingdom. To fulfill our objective, we analyzed several Chinese plants and selected three possessing powerful anti-oxidative activities. The anti-oxidative and anti-inflammatory effects these three Chinese plants, Malus hupehensis, Ophiorrhiza cantonensis, and Psychotria rubra ethanol extracts were then evaluated. First of all, they possessed potent scavenging activity against 1,1-diphenyl-2-picryl hydrazyl, similar with that of ascorbic acid, used as a positive control. Moreover, they inhibited lipopolysaccharide (LPS)- and hydrogen peroxide-induced reactive oxygen species, in a dose-dependent manner, in RAW 264.7 cells. Also, they induced the expression of an anti-oxidative enzyme, heme oxygenase 1, and its upstream transcription factor, nuclear factor-E2-related factor 2. Furthermore, they suppressed LPS-induced nitric oxide (NO) formation, without cytotoxicity. The inhibition of NO formation was the result of the down regulation of inducible NO synthase (iNOS). The suppression of NO and iNOS by the three extracts might be the result of modulation by the upstream transcription factors, nuclear factor ${\kappa}B$ and activator protein-1. Taken together, these results indicate that these three Chinese plants possess potent anti-oxidative and anti-inflammatory activities. Therefore, they might be utilized as promising materials in the field of nutraceuticals.

A study of Cytokine in Peritoneal Fluid of Infertile Patients with Endometriosis (자궁내막증이 있는 불임환자에서 복강액내의 Cytokine에 관한 연구)

  • Kang, Jeong-Bae;Park, Je-Yong;Kim, Bum;Kim, Sung-Joo;Sohn, Woo-Seok;Kim, Hyun-Tae;Jang, Pong-Rheem
    • Clinical and Experimental Reproductive Medicine
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    • v.27 no.1
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    • pp.91-97
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    • 2000
  • Objective: The presence of the various cytokines in human peritoneal fluid has been evaluated incompletely. Changes in cytokine levels may be related to activation of peritoneal macrophage and T-lymphocyte, development of endometriosis, and infertility. This study assesses peritoneal fluid levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in infertile women with endometriosis and normal women without endometriosis. Design: Prospective and case-control study in university hospital. Materials and Methods: Cytokine levels in peritoneal fluid obtained during laparotomy or laparoscopy from 21 patients in infertile patients with endometriosis and 24 controls undergoing laparotomy or laparoscopy with no evidence of pelvic endometriosis were determined by enzyme-linked immunosorbent assay. Results: The mean levels of interleukin-6 in infertile patients with endometriosis and controls were $72.7{\pm}23.7$ pg/ml and $18.5{\pm}9.7$ pg/ml respectively (p=0.02). Similarly, the mean levels of interleukin-8 in infertile patients with endometriosis was significantly higher than that of controls ($445.0{\pm}89.6$, vs $45.1{\pm}48.4$, p=0.04). The mean concentration of interleukin-10 in infertile patients with endometriosis was significantly lower than that of controls ($1.09{\pm}0.04$ vs $2.19{\pm}0.03$, p=0.03). The level of tumor necrosis factor-${\alpha}$ was not significantly different between the two study groups. Conclusions: Increased IL-6 and IL-8 and decreased IL-10 levels in the peritoneal fluid may be related to pathogenesis in the endometriosis and infertility, suggesting that partially contribute to the disturbed immune regulation observed in infertili women with endometriosis.

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The Enzymatic Regulatory Effects of Laninaria japonica Fucoidan Extract in Hepatotoxicity (다시마 푸코이단 추출물의 간독성에서 효소 조절 효능에 관한 연구)

  • Kang, Kum-Suk;Nam, Chun-Suk;Park, Eun-Kyung;Ha, Bae-Jin
    • Journal of Life Science
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    • v.16 no.7 s.80
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    • pp.1104-1108
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    • 2006
  • The purpose of this study was to investigated the effects of Laminaria japonica fucoidan extract (LJFE) through the enzymatic regulation against the hepatotoxicity-inducing carbon tetrachloride $(CCl_4)$ in LJFE and $CCl_4-treated$ rats. LJFE of 100mg/kg concentration was intraperitoneally administered into rats at dose of 1.5m11kg for 14 days. On the day 15, 3.3ml/kg of $CCl_4$ dissolved in olive oil (1:1) was injected 12 hours before anesthetization. We examined the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) in serum of rats, superoxide dismutase(SOD) in mitochondrial fraction, and catalase(CAT), glutathione peroxidase(GPx) in liver homogenate. $CCl_4-treatment$ markedly increased the levels of GOT and GPT, and significantly decreased those of SOD, CAT and GPx. But LIFE pretreatment decreased the levels of GOT and GPT, by 40% and 64%, respectively and increased those of SOD, CAT and GPx, by 114%, 36.1% and 55.9%, respectively These results showed the LIFE had the enzymatic regulatory effects against the hepatotoxicity-inducing $CCl_4$ in the preventive way.

Association of a Single Nucleotide Polymorphism with Economic Traits in Porcine Uncoupling Protein 3 Gene (돼지의 UCP3 유전자의 단일염기서열 변이와 경제형질과의 연관성 분석)

  • Oh, Jae-Don;Lee, Kun-Woo;Jung, Il-Jung;Jeon, Gwang-Joo;Lee, Hak-Kyo;Kong, Hong-Sik
    • Journal of Life Science
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    • v.21 no.1
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    • pp.155-158
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    • 2011
  • Uncoupling protein (UCP) 3 has a number of proposed roles in the regulation of fatty acid metabolism. A number of polymorphisms in the human UCP3 gene have been identified, and the correlation with obesity related phenotypes evaluated. The objective of this study was to identify SNP in porcine UCP3 gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms at position 1405 bp (Genebank accession No : AY739704) in porcine UCP3 gene. The SNP (G150R), located in the exon 3, changed the amino acid to glycine (GGG) from arginine (AGG). This G150R showed three genotypes - GG, GR and RR - by digestion with the restriction enzyme Sma Ⅰ using the PCR-RFLP method. The G150R showed significant effects only on back fat (P<0.05). Animals with the genotype GG had significantly higher back fat thickness (1.358 cm) than animals with the genotype GR (1.288 cm, P<0.05) and RR (1.286 cm, P<0.05). However, the genotypes had no significant association with ADG and days to 90kg. According to results of this study, a G allele of the G150R was found to have a significant effect on back fat thickness. It will be possible to use SNP markers on selected pigs to improve backfat thickness, an important economic trait.

Adipose-Derived Stem Cells Suppress Inflammation Induced by IL-1β through Down-Regulation of P2X7R Mediated by miR-373 in Chondrocytes of Osteoarthritis

  • Jin, Rilong;Shen, Miaoda;Yu, Liedao;Wang, Xuanwei;Lin, Xiangjin
    • Molecules and Cells
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    • v.40 no.3
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    • pp.222-229
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    • 2017
  • Adipose-derived stem cells (ADSCs) were previously considered to have an anti-inflammatory effect, and Interleukin-$1{\beta}$ ($IL-1{\beta}$) was found to be a pro-inflammatory factor in chondrocytes, but the mechanism underlying ADSCs and $IL-1{\beta}$ is unclear. In this study, we investigate whether P2X7 receptor (P2X7R) signalling, regulated by microRNA 373 (miR-373), was involved in the ADSCs and $IL-1{\beta}$ mediated inflammation in osteoarthritis (OA). Chondrocytes were collected from 20 OA patients and 20 control participants, and ADSCs were collected from patients who had undergone abdominal surgery. The typical surface molecules of ASDCs were detected by flow cytometry. The level of nitric oxide (NO) was determined by Griess reagent. Concentrations of prostaglandin E2 (PGE2), interleukin 6 (IL-6), matrix metallopeptidase 3 (MMP-3) were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of IL-6, MMP-3, miR-373 and P2X7R were determined by real-time polymerase chain reaction (PCR), and Western blot was used to detect the protein expression of P2X7R. The typical potential characters of ADSCs were verified. In chondrocytes or OA tissues, the miR-373 expression level was decreased, but the P2X7R expression was increased. $IL-1{\beta}$ stimulation increased the level of inflammatory factors in OA chondrocytes, and ADSCs co-cultured with $IL-1{\beta}$-stimulated chondrocytes decreased the inflammation. OA chondrocytes transfected with the miR-373 inhibitor increased the inflammation level. The miR-373 mimic suppressed the inflammation by targeting P2X7R and regulated its expression, while its effect was reversed by overexpression of P2X7R. $IL-1{\beta}$ induced inflammation in OA chondrocytes, while ADSCs seemed to inhibit the expression of P2X7R that was regulated by miR-373 and involved in the anti-inflammatory process in OA.