• BMB Reports
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• 제30권1호
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• pp.1-6
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• 1997

The ability of Hep-G2 cells to process $[^{125}I]LDL$ under basal conditions was investigated. The receptor-binding and internalization of $[^{125}I]LDL$ increased with the time of incubation in a saturable manner. After 4 h of incubation, 31.4 ng of $[^{125}I]LDL$ was cell bound. The cells rapidly internalized $[^{125}I]LDL$ via specific, receptor-mediated endocytosis. The amount of internalized $[^{125}I]LDL$ reached a maximun of 96.7 ng at 2 h of incubation and remained constant for the next 2 h. The rate of degradation of internalized $[^{125}I]LDL$ proceeded in a linear manner over the entire 4 h of incubation after an initial lag period. The effects of individial fatty acids (C18:0. C18:1, C18:2. and C18:3), differing in their degree of unsaturation. on the receptor-binding, internalization and degradation of $[^{125}I]LDL$ were also investigated. Inclusion of 1.0 mM of each fatty acid into the culture medium significantly increased $[^{125}I]LDL$ metabolism in Hep-G2 cells. Among the fatty acids tested, stearic acid had the least effect on the receptor-binding activity. There were no significant differences among the unsaturated fatty acids in LDL-receptor binding. The effect of individual fatty acids on the $[^{125}I]LDL$ uptake was similar to that of the receptor-binding. showing a significantly lower effect with stearic acid. The amount of degraded material of internalized $[^{125}I]LDL$ was the lowest with stearic acid when it was compared with unsaturated fatty acids.

• 대한임상검사과학회지
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• 제44권3호
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• pp.103-111
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• 2012

Low-Density Lipoprotein cholesterol (LDLC) is the most important marker for the treatment of hyperlipidemia in NCEP-ATP III(National Cholesterol Education Program-Adult Treatment Panel III) guideline. Therefore, LDL cholesterol is pathologically meaningful, accurate measurement should be a top priority. Currently, LDLC is directly measured in most cases, but, the estimate is still used in mass health examination or screening test. This study is about the comparison of LDL-Cholesterol direct measurement with the estimate using various formula (Friedewald: [LDL-F=TC-HDL-TG/5], Nakajima: [LDL-N=TC-HDL-TG/4], Hattori: [LDL-H =0.94TC-0.94HDL-0.19TG], Puavilai: [LDL-P=TC-HDL-TG/6], Carvalho: [LDL-C=3(TC-HDL)/4]) for calculating more accurate value. We analyzed total cholesterol (TC), try-glyceride (TG), high-density lipoprotein cholesterol (HDLC), and LDLC levels of 210 subjects between June and November in 2011. Until now, the Friedewald formula is the most commonly used estimate for the LDLC. When Friedewald formula was applied, the correlation coefficient (r) was 0.940, showing high correlation. But, the result of the direct method was significantly different, compared with those of the Friedewald formula in triglyceride levels ${\geq}400mg/dL$(p<0.05). There was the highest correlation when we used LDL-P formula(r=0.947) in triglyceride levels <400 mg/dl. Also there was the lowest mean difference regardless of triglyceride level. Therefore, the study showed that TG/6 is more precise means of calculation than TG/5. On the other hand, the calculation of LDL-Cholesterol was underestimated, compared with direct measurement. It is necessary to have more data and modified Friedewald formula should be used for the accurate calculation.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.486-494
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• 2006

In order to protect the spermatozoa against cold shock, hen egg yolk is widely used as a cryoprotective agent in semen freezing extenders for domestic animals. The protective action of yolk is largely presumed to be due to low density lipoproteins (LDL). The effects of LDL on sperm quality of bull and northern pike (Esox lucius) after freezing-thawing have been reported, but no study has been made to evaluate the effect of LDL on boar sperm motility and other characteristics. The experiment was carried out to investigate the effect of LDL on the freezing of boar sperm in 0.25 ml straws. The aim was to evaluate the quality of boar spermatozoa cryopreserved in the presence of LDL. Motility of semen cryopreserved in LDL was analyzed and compared to semen cryopreserved with Tris-citric acid-glucose (TCG) and Tris-citric acid-fructose (TCF), two basic freezing extenders containing egg yolk. Similarly, acrosome and plasma membrane integrity were also evaluated and compared to semen cryopreserved with TCG and TCF. Analysis of sperm quality after freeze-thaw showed that the motility, acrosome and plasma membrane integrity were improved with LDL in the extender, as compared to the TCG and TCF. The highest post-thaw integrity of acrosome and plasma membrane and motility were obtained with 9% LDL (w/v). Consequently, the optimum LDL concentration in the extender was 9%. It is also suggested that the concentration of LDL addition is important for the effect on boar sperm protection during freezing and thawing. The percentage of motile spermatozoa was significantly higher after freezing in 9% LDL than in TCG and TCF 54.4% versus 30.4% and 30.1% (p<0.05), respectively. The integrity of acrosome and plasma membrane were also significantly higher at 70.3% and 50.5% respectively with semen frozen in 9% LDL extender compared to TCG at 37.8% and 30.3% and TCF at 36.4% and 29.9%, respectively (p<0.05),. In conclusion, we propose that extender containing LDL extracted from hen egg yolk could be used as a cryoprotective media with a better efficiency than TCG and TCF. LDL improved boar semen quality, allowing better spermatozoa motility, acrosome and plasma membrane integrity after the freeze-thaw process. Furthermore, we found out that the extender with 9% LDL concentration significantly enhanced motility, acrosome and plasma membrane integrity of boar sperm after freezing and thawing.

• 한국수정란이식학회지
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• 제27권3호
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• pp.155-162
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• 2012

This study was designed to determine whether low-density lipoporoteins (LDL) extracted from egg yolk in extender improve the function of Korean Jeju Black Bull semen. The semen was cryopreserved with 5% ethylene glycol (EG) or 7% glycerol (G) extenders containing 10% egg yolk (EY), 4% LDL and 5% EY or 8% LDL. Frozen-thawed sperm were evaluated sperm motility, viability, membrane integrity and acrosome integrity. Post-thawed sperm motility has been significantly higher (p<0.05) in 4% LDL + 5% EY ($69.00%{\pm}4.18$; EG and $63.00%{\pm}9.75$; 7% G) than 8% LDL ($57.00%{\pm}5.70$; EG and $52.00%{\pm}4.47$;G). Treatment of 4% LDL + 5% EY-EG ($66.85%{\pm}5.06$) has been significantly improved sperm viability compared to other treatments except 10% EY - EG. Moreover, in membrane integrity, swollen sperm ratio has been only significantly increased (p<0.05) in 4% LDL + 5% EY - EG ($64.65%{\pm}6.10$) among all treatments. In assess to detect acrosome integrity, especially, AR pattern ratio has been significantly decreased (p<0.05) in 4% LDL + 5% EY - EG among all treatments. In sperm viability as time passes, between 4% LDL + 5% EY and 10% EY, there was no significant difference, but 8% LDL was significantly decreased sperm viability in EG (1 and 2 hrs) and G (30 min, 1, 2, 5 and 12 hrs) extender. However, there were no significant differences among all treatments except 8% LDL-G in sperm membrane integrity. 8% LDL-G has been significantly decreased swollen sperm ratio at 5 hrs after thawed. It is concluded from these results that 4% LDL + 5% EY to the freezing extender showed more positive effect on the frozen-thawed spermatozoa in Korean Jeju Black bull.

• Journal of Nutrition and Health
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• 제31권8호
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• pp.1235-1243
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• 1998

Although an elevated plasma level of high density lipoprotein (HDL) is known as a protective component against the development of atherosclerosis and ensuing coronary heart diseases, the related mechanisms are still not established . It has been clearly demonstrated in the early stages of atherogenesis that adhesion of monocytes and lymphocytes to the vascular endothelium is enhanced via adhesion molecules, and that monocytes and macrophages accumulate in the subendothelial space. The present study has investigated whether isolated plasma HDL plays a role in protection against atherogenesis by inhibiting the expression of vascular cell adhesioin molecule-1(VCAM-1) on the endothelial cells. Effects of plasma native low density lipoprotein (LDL) and ac ethylated LDL(AcLDL) on VCAM-1 expression were also examined by using an immunocytochemical technique. While plasma HDL did not alter the basal expression of VCAM-1 , lipopolysaccharide(LPS) induction of this adhesion modlecule was markedly inhibited at a phyaiological concentration of HDL. In contrast, 30$\mu\textrm{g}$ protein/ml AcLDL increased sifnificantly both basal VCAM-1 expression and its LPD induction , suggesting that this modified LDL enhances leukocyte adhesiion to endothelial cells. Unlike AcLDL , plasma native LDL inhibited significantly VCAM-1 expression. This indicates that LDL did not undergo oxidative modificantion while incubated with endothelial cells. These results suggest that plasam HDL may inhibit atherogenesis by reducing the expression of adhesion molecules, which is a protective mechanism independent of tis reverse cholesterol transport function . Modified LDL is a potent iducer for adhesion molecules in vascular endothelical cells and could play a role in the pathogenesis of atherosclerosis by adhering to blood cells.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.135-145
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• 2020

Purpose: The aim of this study was to evaluate the serum levels of oxidized low-density lipoprotein (oxLDL), anti-oxLDL, and myeloperoxidase (MPO) in hyperlipidemic patients with periodontal disease. Methods: This study included 123 patients with hyperlipidemia categorized based on metabolic control as mild to moderate (H1) (n=66) or poor (H2) (n=57), as well as systemically healthy controls (C) (n=68). Serum levels of lipids, oxLDL, anti-oxLDL, and MPO were evaluated, along with clinical periodontal parameters. Results: The percentage of bleeding on probing (BOP%) and the clinical attachment level were significantly higher in the H2 group than in the C group. Patients with hyperlipidemia had a relatively high risk of developing periodontal disease. The oxLDL and anti-oxLDL levels were higher in H2 patients with periodontitis than in the control or H1 patients with periodontitis. In the H1 and H2 groups, the ratio of total cholesterol to high-density lipoprotein was significantly correlated with gingival index, BOP%, and oxLDL levels. Conclusions: Our findings indicate that the lipoprotein-associated inflammatory mediators of oxLDL, anti-oxLDL, and MPO may play an important role in the relationship between periodontal disease and hyperlipidemia.

• 한국식품영양과학회지
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• 제42권12호
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• pp.1899-1907
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• 2013

복분자 미숙과 물추출물이 콜레스테롤 개선에 미치는 영향을 측정한 결과는 다음과 같다. 간세포주(HepG2 cells)에서 복분자 미숙과 물추출물은 SREBPs를 증가시킴으로써 혈액 내에 LDL을 LDL receptor를 통해서 세포 안으로 흡수시키고, 콜레스테롤 합성에 관여하는 HMG-CoA reductase 활성을 억제하면서 체내 콜레스테롤을 조절하였다. 그러나 HDL의 생성에 관여하는 유전자(ABCA1, SR-B1)는 변화를 보이지 않았다. 결과적으로 복분자 미숙과 물추출물이 LDL receptor를 통해서 LDL을 억제시키고 체내에서는 콜레스테롤 생합성을 억제하였으며, HDL의 생성에는 관여를 하지 않음을 확인하였다. 또한 ApoB1/ApoA1 ratio 값을 통해서 동맥경화 지표를 확인해 본 결과 유의성 있게 수치가 감소함을 확인하였고, 이는 미숙과 물추출물이 콜레스테롤을 개선하여 동맥경화를 예방할 것으로 기대한다. 또한 대식세포(RAW 264.7 cells)에서 복분자 미숙과 물추출물이 CD 36, SR-A 수용체를 억제시킴으로 인해 세포 내의 ox-LDL 의 흡수를 차단시키고, 세포 안에서는 macrophage에 있는 PPAR-${\gamma}$를 억제시킴으로 인해 LDL 산화가 억제되었다. Adipophilin의 활성이 억제됨에 따라 세포 안에 있는 콜레스테롤 방출을 촉진시킴으로 인해 동맥경화를 완화시킬 수 있다고 사료된다.

• 생명과학회지
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• 제20권11호
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• pp.1595-1602
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• 2010

Low density lipoprotein (LDL)의 산화는 동맥경화의 유발과 진행에 결정적 역할을 하는 것으로 알려져 있다. 본 연구에서는 마늘의 주요 대사산물인 allylmercaptan의 산화 low density lipoprotein에 의해 손상된 내피세포의 보호효과에 대하여 실험하였다. Allylmercaptan의 항산화 활성은 thiobarbituric acid substance (TBARS)로 측정하였다. Allylmercaptan은 0.1, 1 및 10 mM의 농도에서 $Cu^{2+}$에 의해 유도된 LDL의 산화를 용량의존적으로 억제하였다. 폐동맥 내피세포를 $37^{\circ}C$, 5% $CO_2$ 상태에서 24시간 동안 미리 배양시킨 후 세측한 다음 다시 24시간 동안 0.1 mg/ml oxidized LDL (ox-LDL)을 첨가하여 배양하였다. 이 때 ox-LDL이 Lactate dehydrogenase (LDH)의 방출과 glutathione (GSH)를 감소시키는 원인으로 세포막 손상의 지표로 LDH와 GSH 함량을 조사하였다. 본 실험 결과 allylmercaptan을 일정 농도 별로 endothelial cell에 첨가하여 배양했을 때 LDH의 방출과 GSH의 감소를 현저하게 억제하였다. Peroxide를 형광분석법으로 24 well plate에서 직접 측정한 결과 allylmercaptan이 폐동맥 내피세포 내에서 ox-LDL 유도 peroxide의 방출을 억제하였다. 그리고 allylmercaptan은 과산화수소의 소거능도 있었다. 본 실험결과 allylmercaptan은 ox-LDL 유도 폐동맥 내피세포를 보호할 수 있었으므로 allylmercaptan은 동맥경화의 예방에 유용할 것으로 생각된다.

• 한국식품위생안전성학회지
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• 제13권1호
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• pp.6-13
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• 1998

해양미생물로부터 사람 Low Density Lipoprotein(LDL)에 대한 항산화 활성 균주를 검색 하였든 바 부산 인근연안에서 항산화 활성이 높은 Bacillus sp. RH-5를 분리 동정하였다. Bacillus sp. RH-5의 항산화 활성물질의 생산 최적 배지는 1.0% glucose, 0.25% polypeptone, 0.25% yeast extract, 0.01% $FeSO_4{\cdot}7H_2O$, 50% sea water 이였다. 이때 최적 조건은 pH 7.0, 배양오도는 $30^{\circ}C$ 및 배양시간은 48시간에서 항산화 활성이 가장 높았다. 사람 LDL을 $1~5\;\mu\textrm{M}\;CuSo_4$ 존재하에서 산화 시킨 결과 Bacillus sp. RH-5 배양액의 ethyl acetate 추출물의 500 및 $1,000\;\mu\textrm{g}/ml$에서 산화가 억제되었으며 또 $5\;\mu\textrm{M}\;CuSo_4$ 존재하에서 산화 시킨 LDL의 전기 영동거리는 native LDL 보다 다소 높았으나 LDL에 ethyl acetate 추출물을 첨가한 경우 그 이동거리는 native LDL과 거의 비슷하였다.

• 생명과학회지
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• 제17권10호
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• pp.1330-1335
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• 2007

마늘을 발효시켜 만든 흑마늘의 지질 산화 억제 및 사람 Low Density Lipoprotein (LDL)에 대하여 항산화 활성을 실험하였다. 표준품으로서 마늘의 주성분인 alliin과 흑마늘의 에탄올과 물 추출물의 전자공여능을 각각 비교하여 측정한 결과 흑마늘 에탄을 추출물이 효능이 가장 높았다. 사람 LDL을 $Cu^{2+}$유도 LDL로 산화시킬 때 그 항산화능은 각 시료를 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$ 씩 첨가하며 TSARS를 측정한 결과 에탄을 추출물이 항산화 활성이 가장 높았으며 용량 의존형으로 나타났다. 흑마늘의 에탄올과 물추출물을 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$ 첨가한 후 J774 유도 산화에 대한 항산화 효과를 측정한 결과 각 추출물은 항산화 효과가 있었고 용량 의존형의 항산화 활성을 나타내었다. 흑마늘의 각 추출물을 이용한 실험에서 전기영동 이동상은 대조구에 비하여 $10\;{\mu}g/ml$ 및 $20\;{\mu}g/ml$에서 산화를 억제하였고 공액 2중 결합에 의한 실험에서도 항산화 효과가 있었으며 $20\;{\mu}g/ml$의 농도에서 거의 억제되었다.