• Bulletin of the Korean Chemical Society
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• 제16권5호
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• pp.401-406
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• 1995

The P. fragi lipase overexpressed in E. coli as a fusion protein of 57 kilodalton (kDa) has been purified through glutathione-agarose affinity chromatography by elution with free glutathione. The general properties of the purified GST-fusion protein were characterized by observing absorbance of released p-nitrophenoxide at 400 nm which was hydrolyzed from the substrate p-nitrophenyl palmitate. The optimum condition was observed at 25 $^{\circ}C$, pH 7.8 with 0.4 ${\mu}g$ of protein and 1.0 mM substrate in 0.6% (v/v) TritonX-100 solution. Also the lipase was activated by Ca+2, Mg+2, Ba+2 and Na+ but it was inhibited by Co+2 and Ni+2. pGEX-2T containing P. fragi lipase gene as expression vector was named pGL191 and used as a template for the site-directed mutagenesis by sequential PCR steps. A Ser-His-Asp catalytic triad similar to that present in serine proteases may be present in Pseudomonas lipase. Therefore, the PCR fragments replacing Asp217 to Arg and His260 to Arg were synthesized, and substituted for original fragment in pGL19. The ligated products were transformed into E. coli NM522, and pGEX-2T harboring mutant lipase genes were screened through digestion with XbaI and StuI sites created by mutagenic primers, respectively. No activity of mutant lipases was observed on the plate containing tributyrin. The purified mutant lipases were not activated on the substrate and affected at pH variation. These results demonstrate that Asp217 and His260 are involved in the catalytic site of Pseudomonas lipase.

• The Korean Journal of Physiology and Pharmacology
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• 제13권3호
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• pp.153-159
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• 2009

We investigated whether deficiency of inducible nitric oxide synthase (iNOS) could prevent isoproterenol-induced cardiac hypertrophy in iNOS knockout (KO) mice. Isoproterenol was continuously infused subcutaneously (15 mg/kg/day) using an osmotic minipump. Isoproterenol reduced body weight and fat mass in both iNOS KO and wild-type mice compared with saline-infused wild-type mice. Isoproterenol increased the heart weight in both iNOS KO and wild-type mice but there was no difference between iNOS KO and wild-type mice. Posterior wall thickness of left ventricle showed the same tendency with heart weight. Protein level of iNOS in the left ventricle was increased in isoproterenol-infused wild-type mice. The gene expression of interleukin-6 (IL-6) and transforming growth factor-${\beta}$ (TGF-${\beta}$) in isoproterenol-infused wild-type was measured at 2, 4, 24, and 48-hour and isoproterenol increased both IL-6 (2, 4, 24, and 48-hour) and TGF-${\beta}$ (4 and 24-hour). Isoproterenol infusion for 7 days increased the mRNA level of IL-6 and TGF-${\beta}$ in iNOS KO mice, whereas the gene expression in wild-type mice was not increased. Phosphorylated form of extracellular signal-regulated kinases (pERK) was also increased by isoproterenol at 2 and 4-hour but was not increased at 7 days after infusion in wild-type mice. However, the increased pERK level in iNOS KO mice was maintained even at 7 days after isoproterenol infusion. These results suggest that deficiency of iNOS does not prevent isoproterenol-induced cardiac hypertrophy and may have potentially harmful effects on cardiac hypertrophy.

• The Korean Journal of Physiology and Pharmacology
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• 제11권2호
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• pp.71-77
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• 2007

Cisplatin treatment increases the excretion of inorganic phosphate in vivo. However, the mechanism by which cisplatin reduces phosphate uptake through renal proximal tubular cells has not yet been elucidated. We examined the effect of cisplatin on $Na^+$-dependent phosphate uptake in opossum kidney (OK) cells, an established proximal tubular cell line. Cells were exposed to cisplatin for an appropriate time period and phosphate uptake was measured using $[^{32}P]$-phosphate. Changes in the number of phosphate transporter in membranes were evaluated by kinetic analysis, $[^{14}C]$phosphonoformic acid binding, and Western blot analysis. Cisplatin inhibited phosphate uptake in a time- and dose-dependent manner, and also the $Na^+$-dependent uptake without altering $Na^+$-independent uptake. The cisplatin inhibition was not affected by the hydrogen peroxide scavenger catalase, but completely prevented by the hydroxyl radical scavenger dimethylthiourea. Antioxidants were ineffective in preventing the cisplatin-induced inhibition of phosphate uptake. Kinetic analysis indicated that cisplatin decreased Vmax of $Na^+$-dependent phosphate uptake without any change in the Km value. $Na^+$-dependent phosphonoformic acid binding was decreased by cisplatin treatment. Western blot analysis showed that cisplatin caused degradation of $Na^+$-dependent phosphate transporter protein. Taken together, these data suggest that cisplatin inhibits phosphate transport in renal proximal tubular cells through the reduction in the number of functional phosphate transport units. Such effects of cisplatin are mediated by production of hydroxyl radicals.

• Gut and Liver
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• 제12권6호
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• pp.682-693
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• 2018

Background/Aims: Intestinal barrier dysfunction is a hallmark of inflammatory bowel diseases (IBDs) such as ulcerative colitis. This dysfunction is caused by increased permeability and the loss of tight junctions in intestinal epithelial cells. The aim of this study was to investigate whether estradiol treatment reduces colonic permeability, tight junction disruption, and inflammation in an azoxymethane (AOM)/dextran sodium sulfate (DSS) colon cancer mouse model. Methods: The effects of $17{\beta}$-estradiol (E2) were evaluated in ICR male mice 4 weeks after AOM/DSS treatment. Histological damage was scored by hematoxylin and eosin staining and the levels of the colonic mucosal cytokine myeloperoxidase (MPO) were assessed by enzyme-linked immunosorbent assay (ELISA). To evaluate the effects of E2 on intestinal permeability, tight junctions, and inflammation, we performed quantitative real-time polymerase chain reaction and Western blot analysis. Furthermore, the expression levels of mucin 2 (MUC2) and mucin 4 (MUC4) were measured as target genes for intestinal permeability, whereas zonula occludens 1 (ZO-1), occludin (OCLN), and claudin 4 (CLDN4) served as target genes for the tight junctions. Results: The colitis-mediated induced damage score and MPO activity were reduced by E2 treatment (p<0.05). In addition, the mRNA expression levels of intestinal barrier-related molecules (i.e., MUC2, ZO-1, OCLN, and CLDN4) were decreased by AOM/DSS-treatment; furthermore, this inhibition was rescued by E2 supplementation. The mRNA and protein expression of inflammation-related genes (i.e., KLF4, NF-${\kappa}B$, iNOS, and COX-2) was increased by AOM/DSS-treatment and ameliorated by E2. Conclusions: E2 acts through the estrogen receptor ${\beta}$ signaling pathway to elicit anti-inflammatory effects on intestinal barrier by inducing the expression of MUC2 and tight junction molecules and inhibiting pro-inflammatory cytokines.

• 대한의생명과학회지
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• 제15권4호
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• pp.319-326
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• 2009

Extracellular ATP elicits diverse physiological effects by binding to the G-protein-coupled P2Y receptors on the plasma membrane. In addition to the short-term effects of extracellular nucleotides on cell functions, there is evidence that such purinergic signalling can have long-term effects on cell proliferation, differentiation and death. The 3T3-L1 cell line derived from mouse embryo is a well-established and commonly utilized in vitro model for adipocytes differentiation and function. However, the distributions and roles of P2Y subtypes are still unknown in the preadipocyte. In this study, we identified the distributions and roles of P2Y subtypes in preadipocyte using $Ca^{2+}$ imaging and realtime PCR. ATP increased the $[Ca^{2+}]_i$ in a concentration-dependent manner. ATP increased $Ca^{2+}$ in absence and/or presence of extracellular $Ca^{2+}$. Suramin, non-selective P2Y blocker, largely blocked the ATP-induced $Ca^{2+}$ response. U73122, a PLC inhibitor, completely inhibited $Ca^{2+}$ mobilization in 3T3-L1 cells. The mRNA expression by realtime PCR of P2Y subtypes was $P2Y_2:P2Y_5:P2Y_6=1.0:12.5:0.3$. In conclusion, we showed that $P2Y_5$ receptor is a dominant purinergic receptor in preadipocytes, and multiple P2Y receptors could involve in differentiation and migration via regulating of intracellular calcium concentration.

• 대한화장품학회지
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• 제45권2호
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• pp.117-129
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• 2019

올벚나무 잎 추출물을 제조하고 LPS로 자극시킨 RAW 264.7 대식세포에 대한 항염 효과를 조사하였다. 추출물 및 분획물(n-hexane, ethyl acetate, n-butanol 및 water)에 대하여 활성 실험을 진행한 결과, $100{\mu}g/mL$ 농도에서 ethyl acetate (EtOAc) 분획물이 세포독성 없이 76.3%의 NO 생성 억제 효과를 나타내었다. 또한 EtOAc 분획물이 농도 의존적으로 NO 생성을 효과적으로 억제하고 있음을 확인하였다. 이러한 항염 효과에 대한 추가적인 기전 연구를 진행한 결과, EtOAc 분획물이 $PGE_2$, $IL-1{\beta}$ 및 IL-6의 생성을 감소시켰으며, iNOS와 COX-2 단백질의 발현도 억제시키는 것을 확인하였다. EtOAc분획물에서 활성 성분을 규명하기 위하여 column chromatography를 진행하였으며 5개의 화합물을 분리 동정하였다. ursolic acid (1), prunasin (2), methyl p-coumarate (3), kaempferol (4), astragalin (5). 분리된 compound 1 - 5는 모두 올벚나무 잎에서 처음 분리된 물질이다. 분리된 화합물을 대상으로 활성 실험을 진행한 결과, 플라보노이드 compound 4와 5가 NO 생성을 억제하고 있음을 확인하였다. 이상의 결과를 바탕으로, 플라보노이드를 유효성분으로 함유하는 올벚나무 잎은 항염 효과를 갖는 천연 소재로서 활용이 가능할 것이라 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.548-555
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• 2018

Objective: This experiment was conducted to investigate whether asparagine (Asn) could improve liver energy status in weaning pigs when challenged with lipopolysaccharide. Methods: Forty-eight weaned pigs ($Duroc{\times}Large\;White{\times}Landrace$, $8.12{\pm}0.56kg$) were assigned to four treatments: i) CTRL, piglets received a control diet and injected with sterile 0.9% NaCl solution; ii) lipopolysaccharide challenged control (LPSCC), piglets received the same control diet and injected with Escherichia coli LPS; iii) lipopolysaccharide (LPS)+0.5% Asn, piglets received a 0.5% Asn diet and injected with LPS; and iv) LPS+1.0% Asn, piglets received a 1.0% Asn diet and injected with LPS. All piglets were fed the experimental diets for 19 d. On d 20, the pigs were injected intraperitoneally with Escherichia coli LPS at $100{\mu}g/kg$ body weights or the same volume of 0.9% NaCl solution based on the assigned treatments. Then the pigs were slaughtered at 4 h and 24 h after LPS or saline injection, and the liver samples were collected. Results: At 24 h after LPS challenge, dietary supplementation with 0.5% Asn increased ATP concentration (quadratic, p<0.05), and had a tendency to increase adenylate energy charges and reduce AMP/ATP ratio (quadratic, p<0.1) in liver. In addition, Asn increased the liver mRNA expression of pyruvate kinase, pyruvate dehydrogenase, citrate synthase, and isocitrate dehydrogenase ${\beta}$ (linear, p<0.05; quadratic, p<0.05), and had a tendency to increase the mRNA expression of hexokinase 2 (linear, p<0.1). Moreover, Asn increased liver phosphorylated AMP-activated protein kinase (pAMPK)/total AMP-activated protein kinase (tAMPK) ratio (linear, p<0.05; quadratic, p<0.05). However, at 4 h after LPS challenge, Asn supplementation had no effect on these parameters. Conclusion: The present study indicated that Asn could improve the energy metabolism in injured liver at the late stage of LPS challenge.

• 한국유기농업학회지
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• 제28권4호
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• pp.659-677
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• 2020

본 실험에서는 익모초 지상부 에탄올 추출물의 항산화 및 항염증 효과를 확인하여 건강 기능성 소재로서의 가능성을 평가하고자 하였다. DPPH 및 ABTS radical 소거 활성, 환원력, 총 폴리페놀 및 플라보노이드 함량을 통해 익모초의 항산화능을 측정한 결과, 400 ㎍/mL, 1500 ㎍/mL의 농도에서 57.8%, 62.3%의 DPPH 및 ABTS radical 소거활성을 보였고 환원력 또한 농도 의존적으로 증가하는 경향을 보였다. 총 폴리페놀 함량 및 플라보노이드 함량은 1 mg/mL의 농도에서 각각 51.40 ± 0.47 mg of gallic acid equivalents/g, 73.28 ± 0.10 mg of rutin equivalents/g로 나타났으며, 익모초 추출물은 세포 내 ROS의 생성 억제에 있어서 유의적인 효과를 보였다. 익모초의 항염증 효과를 측정한 결과, LPS로 자극해 활성화된 RAW 264.7 cell에서 익모초 추출물(0~400 ㎍/mL)의 세포 독성은 없었으며 LPS 처리로 유도된 세포의 형태학적 변화도 농도의존적으로 완화되는 경향을 보였다. NO 발생량은 LPS 처리군과 비교해 익모초 추출물 처리 시 농도 의존적으로 감소하였고, 400 ㎍/mL에서는 90.3%로 NO의 생성이 억제되었다. 염증성 cytokine (TNF-α, IL1-β)의 생성도 유의적으로 감소하였고 NO를 생성하는 염증성 단백질 iNOS의 발현 또한 억제되었으며 이와 같은 염증성 단백질의 전사를 조절하는 NF-κB (NF-κB, IκB-α) 및 MAPK (ERK, p38)의 인산화 및 활성화 또한 익모초 추출물 처리로 인해 억제됨을 확인하였다. 따라서 익모초 추출물은 NF-κB signaling pathway 및 ERK/p38 MAPK cascade pathway의 조절을 통해 염증성 단백질 및 염증인자의 발현을 감소시킨다고 볼 수 있다. 이러한 결과를 토대로 익모초 지상부 에탄올 추출물은 천연 기능성 소재로서 활용될 가능성이 있으며, 본 연구 결과는 익모초의 고부가가치 향상을 위한 기초자료로 도움이 될 것으로 생각된다.

• 대한본초학회지
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• 제33권4호
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• pp.59-67
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• 2018

Objectives : Ojeoksan, originally recorded in an ancient Korean medicinal book named "Donguibogam" and has been used for the treatment of circulation disorder of blood which was called blood accumulation (血積) in Korean medicine. Therefore, this study was carried out to investigate the beneficial effect of OJS on vascular inflammation in HUVECs. Methods : We evaluated the effect of OJS on the expression of cell adhesion molecules and protective role in HUVEC stimulated by TNF-${\alpha}$ by using Western blot. Results : Pretreatment with OJS decreased the adhesion of HL-60 cells to TNF-${\alpha}$-induced HUVEC. OJS suppressed TNF-${\alpha}$-induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and endothelial cell selectin (E-selectin). Moreover, OJS significantly decreased TNF-${\alpha}$-induced production of intracellular reactive oxygen species (ROS); and inhibited the phosphorylation of $I{\kappa}B-{\alpha}$ in the cytoplasm compared to the experimental group. Pretreatment with OJS inhibited the trans-location of NF-${\kappa}B$ p65 to the nucleus. OJS also inhibited phosphorylation of MAPKs compared to the experimental group. OJS significantly increased the protein expression of Nrf2 and HO-1. Conclusions : Ojeoksan has a protective effect on vascular inflammation, and might be a potential therapeutic agent for early atherosclerosis.

• Molecules and Cells
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• 제27권4호
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• pp.423-428
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• 2009

Superoxide dismutases (SODs) constitute the first line of cellular defense against oxidative stress in plants. SODs generally occur in three different forms with Cu/Zn, Fe, or Mn as prosthetic metals. We cloned the full-length cDNA of the Thellungiella halophila Cu/Zn-SOD gene ThCSD using degenerate RT-PCR and rapid amplification of cDNA ends (RACE). Sequence analysis indicated that the ThCSD gene (GenBank accession number EF405867) had an open reading frame of 456 bp. The deduced 152-amino acid polypeptide had a predicted molecular weight of 15.1 kDa, an estimated pI of 5.4, and a putative Cu/Zn-binding site. Recombinant ThCSD protein was expressed in Escherichia coli and assayed for SOD enzymatic activity in a native polyacrylamide gel. The SOD activity of ThCSD was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide, confirming that ThCSD is a Cu/Zn-SOD. Northern blotting demonstrated that ThCSD is expressed in roots, stems, and leaves. ThCSD mRNA levels increased by about 30-fold when plants were treated with sodium chloride (NaCl), abscisic acid (ABA), and indole-acetic acid (IAA) and by about 50-fold when treated with UVB light. These results indicate that ThCSD is involved in physiological pathways activated by a variety of environmental conditions.