• 대한예방한의학회지
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• 제16권2호
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• pp.113-124
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• 2012

The oxidative modification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis. Oxidized LDL(oxLDL) is captured into macrophage and stimulates to form macrophage foam cell. And it can induce an inflammation and smooth muscle proliferation in atherosclerotic plaque. Objective : In this study, we aimed to investigate the effect of Bupleuri radix(SH) on the foam cell formation, a critical initiation stage of atherosclerosis. Methods : To achieve the goal, we examined the effect of SH on LDL oxidation, nitric oxide production in RAW264.7, and the effect of SH on cupuric sulfate-induced cytotoxicity, LDH release, and macrophage activity. Results : SH inhibited the formation of oxidized LDL from native LDL in RAW264.7 cell culture, and decreased the release of LDH from cupric sulfate-stimulated RAW264.7 cell. In other experiments, SH activated RAW264.7 cell, and prolonged the survival time, and inhibited foam cell formation induced by oxLDL in Raw 264.7 cells. Conclusion : These results showed that SH might prevent atherosclerosis by controlling the early stages of foam cell formation.

• 폴리머
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• 제25권5호
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• pp.679-690
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• 2001

폴리에테르형 기포개방제를 사용한 고탄성 폴리우레탄 발포체의 제조에서 기포개방제의 농도변화가 계의 반응속도, 유변학적 성질, 발포체의 구조적인 안정성, 형태학적 성질 및 개방기포의 함량 등에 미치는 영향을 조사하고 이를 통하여 기포개방에서 기포개방제의 역할을 알아보았다. 또한 기포개방제의 농도에 따른 발포체의 기계적 물성을 관찰하였다. 기포개방제의 높은 친수성으로 인해 우레아 생성반응이 지연됨을 관찰하였다. 유변학적 성질의 관찰을 통하여 기고개방제의 농도 증가에 따라 계의 점도저하와 tan $\delta$의 증가를 확인하였고 이로 인해 얻어진 발포체는 낮은 구조적인 안정성과 높은 개방기포 함량을 나타내었다. 기포개방제의 농도 증가에 따라 matrix의 파괴와 matrix내 수소결합된 우레아의 고른 분산을 발포체의 형태학적 성질의 관찰로 확인할 수 있었다. 결론적으로 고탄성 폴리우레탄 발포체의 제조시 기포개방제의 높은 친수성에 기인하여 matrix의 탄성특성 저하가 일어나고 이로 인해 높은 개랑기포 함량을 가진 발포체가 형성됨을 알 수 있었다. 발포체의 경도, 인장강도, 인열강도, 신율 등은 기포개방제의 농도 증가에 따라 저하하였다.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.93-98
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• 1996

Lipopretein(a)[Lp(a)] is a macromolecular complex found in human plasma that combines structural elements composed of LDL and apo(a), and that is associated with premature coronary heart disease and stroke. In this study, various samples which consisted of normal and abnormal LDL and LP(a) were selected for compar-ison. The above samples were incubated with copper in order to oxidize and to compare atheroma formation, in vitro and free radical formation of Lp(a) was decreased compared to purified LDl. And LDL or Lp(a) from a 40 year old donor was higher in the free radical formation than that fro, a 20 years old donor. In order to investigate the macrophage foam cell formation, oxidized LDL of Lp(a) was incubated with human monocyte derived macrophage(HMDM). Oxidized samples enhanced on acceptability f foam cell formation by HMDM were compared to the control group. Also, structural change of LDL and Lp(a) against oxidation times were found from HPLC mapping.

• 대한한의학회지
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• 제28권2호통권70호
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• pp.185-199
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• 2007

Objectives : This study was carried out to investigate the inhibitive effect of a combined-herb prescription of Dansam-san (DSS) on formation of foam cells and cytokine. Methods : Experimental formation of foam cells was induced on macrophage RAW 264.7 with ox-LDL. The effect of DSS extract was observed by measuring the changes of CD36, $PPAR-{\Gamma}$, MMP-9, iNOS expression and changes of formation level of foam cells after treating experimentally induced foam cells with DSS extract. Then the antioxidative effect of DSS extract was compared with butylated hydroxyanisole (BHA). Result and Conclusions : Results obtained are as follows: 1. DSS extract showed significant antioxidative effect at 8 mg/ml or more. 2. DSS extract inhibited the formation of foam cells. 3. DSS extract inhibited the creation and revelation of conversion-related material about foam cells. 4. DSS extract prohibited the increase of smooth muscle of vessels.

• Biomolecules & Therapeutics
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• 제26권2호
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• pp.121-129
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• 2018

Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and apoptosis play critical roles in the pathogenesis of atherosclerosis. Thioredoxin-1 (Trx) is an antioxidant that potently protects various cells from oxidative stress-induced cell death. However, the protective effect of Trx on ox-LDL-induced macrophage foam cell formation and apoptosis has not been studied. This study aims to investigate the effect of recombinant human Trx (rhTrx) on ox-LDL-stimulated RAW264.7 macrophages and elucidate the possible mechanisms. RhTrx significantly inhibited ox-LDL-induced cholesterol accumulation and apoptosis in RAW264.7 macrophages. RhTrx also suppressed the ox-LDL-induced overproduction of lectin-like oxidized LDL receptor (LOX-1), Bax and activated caspase-3, but it increased the expression of Bcl-2. In addition, rhTrx markedly inhibited the ox-LDL-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38 mitogen-activated protein kinases (MAPK). Furthermore, anisomycin (a p38 MAPK activator) abolished the protective effect of rhTrx on ox-LDL-stimulated RAW264.7 cells, and SB203580 (a p38 MAPK inhibitor) exerted a similar effect as rhTrx. Collectively, these findings indicate that rhTrx suppresses ox-LDL-stimulated foam cell formation and macrophage apoptosis by inhibiting ROS generation, p38 MAPK activation and LOX-1 expression. Therefore, we propose that rhTrx has therapeutic potential in the prevention and treatment of atherosclerosis.

• Molecules and Cells
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• 제28권3호
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• pp.175-181
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• 2009

In hypertriglyceridaemic individuals, atherosclerogenesis is associated with the increased concentrations of very low density lipoprotein (VLDL) and VLDL-associated remnant particles. In vitro studies have suggested that VLDL induces foam cells formation. To reveal the changes of the proteins expression in the process of foam cells formation induced by VLDL, we performed a proteomic analysis of the foam cells based on the stimulation of differentiated THP-1 cells with VLDL. Using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, 14 differentially expressed proteins, containing 8 up-regulated proteins and 6 down-regulated proteins were identified. The proteins are involved in energy metabolism, oxidative stress, cell growth, differentiation and apoptosis, such as adipose differentiation-related protein (ADRP), enolase, S100A11, heat shock protein 27 and so on. In addition, the expression of some selected proteins was confirmed by Western blot and RT-PCR analysis. The results suggest that VLDL not only induces lipid accumulation, but also brings about foam cells diverse characteristics by altering the expression of various proteins.

• 대한기계학회논문집A
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• 제27권10호
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• pp.1686-1694
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• 2003

The foam-filled tube beams can be used for the front rail and firewall structures to absorb impact energy during frontal or side collision of vehicles. In the case of side collision where bending is involved in the crushing mechanism, the foam filler would be effective in maintaining progressive crushing of the thin-walled structures so that much impact energy could be absorbed. In this study, bending behaviors of the closed-cell-aluminum-alloy-foam-filled stainless steel tube were investigated. The various foam-filled specimens including piecewise fillers were prepared and tested. The aluminum-alloy-foam filling offered the significant increase of bending resistance. Their suppression of the inward fold formation at the compression flange as well as the multiple propagating folds led to the increase of load carrying capacity of specimens. Moreover, the piecewise foams would provide the easier way to fill the thin-walled shell structures without the drawback of strength.

• Journal of Nutrition and Health
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• 제36권9호
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• pp.908-917
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• 2003

It has been proposed that oxidative modification of LDL (oxLDL) plays a significant role in the pathogenicity of atherogenesis. We tested the hypothesis that chitin and chitosan may function as antioxidants with respect to 0.1 mg cholesterol/ml LDL incubated with 5 $\mu$ M Cu$^2$$^{+}$alone or in the P338Dl mouse macrophage system using L-ascorbic acid as a standard classical antioxidant. The degree of oxLDL formation was ascertained by the relative electrophoretic mobility (rEM) in the combination of thiobarbituric acid reactive substances (TBARS) levels, and the cytotoxicity of oxLDL was detected by macrophage viability. The oxLDL uptake and foam cell formation of macrophages were measured by Oil Red O staining. Incubation with Cu$^2$$^{+}$and macrophages increased rEM of LDL and stimulated TBARS formation. Culture of macrophages with LDL in the presence 5 $\mu$ M Cu$^2$$^{+}$induced macrophage death. In cell-free system 200 $\mu$g/ml water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation. Water-soluble chitosan and chitosan-oligosaccharide blocked oxLDL formation near-completely relative to L-ascorbic acid, whereas water-soluble chitin and chitin-oligosaccharide had no measurable antioxidant effect. In macrophage system water-soluble chitosan and chitosan-oligosaccharide blocked oxidation of LDL with a significant increase in cell viability, and decreased TBARS in medium. As for the inhibitory effect on macrophage foam cell formation, chitosan and its oligosaccharide, but not watersoluble chitin, revealed the effectiveness. The endothelial expression of lectin-like oxLDL receptor-1 (LOX-1) was tested by Western blot analysis, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide blocked LOX-1 expression. These results indicate that water-soluble chitosan and its oligosaccharide showed the inhibitory effect on Cu$^2$$^{+}$-induced LDL oxidation of macrophages, and chitosan, chitosan-oligosaccharide and chitin-oligosaccharide had blocking effect on oxLDL receptor expression in the human umbilical vein endothelial system. Thus, water-soluble chitosan and its oligosaccharides possess anti-atherogenic potentials possibly through the inhibition of macrophage LDL oxidation or endothelial oxLDL receptor expression depending on chemical types.l types.

• 폴리머
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• 제26권2호
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• pp.218-226
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• 2002

산화에틸렌 함량, 분자량 및 분자사슬의 구조가 다른 폴리에테르형 기포개방제를 사용하여 고탄성 폴리우레탄 발포체를 제조하고 이 때 기포개방제의 구조 변화가 계의 반응속도, 유변학적 성질, 발포체의 구조적인 안정성, 개방기포 함량 및 기계적인 성질 등에 미치는 영향을 조사하였다. 기포개방제의 산화에틸렌 함량 증가와 분자사슬에 에스테르 결합의 도입에 따라 우레아 생성 반응이 지연되었으나, 기포개방제의 분자량은 큰 영향이 없음을 관찰하였다. 유변학적 성질의 관찰로 기포개방제의 산화에틸렌 함량과 분자량의 증가에 따라 반응물의 점도와 저장탄성율의 감소를 확인하였고, 이 때 얻어진 발포체는 낮은 구조적인 안정성과 높은 개방기포 함량을 가졌다. 에스테르 결합이 도입된 기포개방제는 가장 낮은 점도와 저장탄성율을 나타내었고 제조된 발포체는 높은 개방기포 함량을 가졌으며, 또한 에스테르 결합에 의해 증가된 분자간 힘으로 인해 구조적인 안정성이 증가하였다 발포체의 경도, 인장강도, 인열강도, 신율은 기포개방제의 산화에틸렌 함량과 분자량의 증가에 따라 저하하였으나, 에스테르 결합이 도입된 기포개방제의 경우에는 우수한 인장강도, 인열강도, 신율을 나타내었다.

• IMMUNE NETWORK
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• 제20권3호
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• pp.22.1-22.21
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• 2020

In the progression of atherosclerosis, macrophages are the key immune cells for foam cell formation. During hyperlipidemic condition, phagocytic cells such as monocytes and macrophages uptake oxidized low-density lipoproteins (oxLDLs) accumulated in subintimal space, and lipid droplets are accumulated in their cytosols. In this review, we discussed the characteristics and phenotypic changes of macrophages in atherosclerosis and the effect of cytosolic lipid accumulation on macrophage phenotype. Due to macrophage plasticity, the inflammatory phenotypes triggered by oxLDL can be re-programmed by cytosolic lipid accumulation, showing downregulation of NF-κB activation followed by activation of anti-inflammatory genes, leading to tissue repair and homeostasis. We also discuss about various in vivo and in vitro models for atherosclerosis research and next generation sequencing technologies for foam cell gene expression profiling. Analysis of the phenotypic changes of macrophages during the progression of atherosclerosis with adequate approach may lead to exact understandings of the cellular mechanisms and hint therapeutic targets for the treatment of atherosclerosis.