Function and Significance of Very Low Density Lipoprotein Receptor Subtype Ⅱ

To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype Ⅱ in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type Ⅰ VLDLR) and the other without the O-linked sugar region (type Ⅱ VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of^125I-VLDL or ^125I-β-VLDL of ldl-A7 cells transfected with type Ⅰ VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type Ⅱ VLDLR recombinant (ldl-A7 VRⅡ). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in IdI-A7-VR Ⅰ were much higher than those in ldl-A7-VR Ⅱ, and IdI-A7-VR Ⅰ could transform into foam cells notably. It was suggested that type Ⅰ VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type Ⅰ VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type Ⅱ VLDLR。     

Study of the Mechanism of Essential Garlic Oil Inhibiting Interleukin1 Induced Monocyte Adhesion to Endothelial Cells

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Expression of Monocyte Chemoattractant Protein-1 in Monocytes and Effects of Native and Oxidized Very Low Density Lipoproteins

Itiswellknownthattherearetwokindsoffoamcellsderivedfrommonocytemacrophagesandsmoothmusclecellsrespectivelyinatheroscleroticplaques.Thepenetrationandaccumulationofmonocytemacrophagesderivedfoamcellsunderanintactendotheliumisoneofearlylesions,thusinvestigationonmechanismformonocytemigratingintosubendothelialspacesisveryimportant.Previousstudieshaveshownthatendothelialcellsandsmoothmusclecellsincultureconstitutivelyexpressmonocytechemoattractantprotein1[l].Monocytechemoattractantprotein--1(MCP-l…     

Influence of Oxidized Low Density Lipoprotein on the Proliferation of Human Artery Smooth Muscle Cells in vitro

The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of cultured human vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gra-dient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (35, 60, 85, 110, 135 and 160 μg/mL) for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in athero-sclerotic plaque. ox-LDL at a concentration of 35 μg/mL demonstrated the strongest proliferation in-ducement, and at a concentration of 135 μg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 μg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually. ox-LDL at higher con-centrations promoted more apoptotic vSMCs. ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs. ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.     

Influence of Traditional Chinese Medicine Qingjieling on LFA-1-Dependent Leukocyte Adhesion to Endothelial Cells

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The Ca^2＋ Over Loading Effect of Oxidized Low Density Lipoprotein on Macrophages

Purpose The Ca^2＋ over loading effect of oxidized low density lipoprotein （OLDL） on macrophages and its mechanisms were explored in these studies. Methods C57BL/6J mouse peritoneal macrophages were incubated in 10mg/L oxidized low density lipoprotein （OLDL）, the intracellular Ca^2＋ level was determined with the technique of Ca^2＋ fluorescent indicator, and the membranous Ca^2＋-ATPase activity was determined with the assay of NADH-oxidizing coupling spectrum-alteration. Results The intracellular Ca^2＋ level was 2.7 times higher than the control, and the membranous Ca^2＋-ATPase activity was 24.0% of the control. Conclusion OLDL exerted a Ca^2＋ over loading effect on macrophages, and this was probably related to the opening of the membranous Ca^2＋ channels and the inactivating of the membranous Ca^2＋-ATPase.     

Polylactic Acid Nanoparticles Targeted to Brain Microvascular Endothelial Cells

In this work, blank polylactic acid （PLA） nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells （BMECs） targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can he loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 （T-80） can facilitate BMECs targeting of PLA nanoparticles.     

Morphological Changes of Aorta and Total Cholesterol, High Density Lipoprotein, Oxidized Low Density Lipoprotein, Nitric Monoxide and Lipide Peroxidation in Serum after Arcuate Nucleus Lesioned

After arcuate nucleus of hypothalamus lesioned with monosodium glutamate and cutting infundibulum, morphological changes of aorta and total cholesterol, high density lipoprotein, oxidized low density lipoprotein, nitric monoxide and lipid peroxidation in serum were investigated to explore the effect of hypothalamic arcuate nucleus on the development of atherosclerosis. In experimental group of arcuate nucleus lesioned, degeneration of endothelial cells and edematous nuclei of endothelial can be observed, vesicles of various sizes in subendothelial tissue and smooth muscle cells migrated from tunica media to tunica intima through ruptured elastic interna, and the levels of total cholesterol, oxidized low density lipoprotein and lipid peroxidation in serum was significant higher and nitric monoxide was lower than that of control subjects. After cutting infundibulum, degeneration of endothelial cells with edematous nucleus and proliferous collagenous fibers around ruptured myo-endothelial junction were also observed. The structure of control group remained intact. Results suggest that hypothalamic arcuate nucleus might be of significance regulative effect in the development of atherosclerosis.     

Effects of Oxidized Low Density Lipoprotein on the Expression and Function of ABCA1 in Macrophages

In the present study, we examined the regulation of the expression and function of ABCA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-I for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol loaded by acetyl LDL (ac-LDL), and 9.78% cholesterol in ox-LDL group. The level of ABCA1 mRNA increased about three times either when cells were incubated with .100 μg/mL ac-LDL or with 100 μg/mL ox-LDL. However, the level of ABCA1 protein rose by 1.57 times in ac-LDL group and 1.26 times in ox-LDL group. These results demonstrated that ox-LDL had different effect on the expression and function of ABCA1, ox-LDL might decrease the cholesterol efflux mediated by ABCA1 through other unknown mechanisms.     

巨噬细胞和内皮细胞对不同氧化修饰程度低密度脂蛋白的结合与降解

低密度脂蛋白(LDL)经氧化修饰后可被巨噬细胞和内皮细胞所识别,被两种细胞的结合量与降解量随LDL修饰程度升高而增加。     

柚皮苷抑制高糖诱导的脐静脉内皮细胞与单核细胞的粘附作用

目的研究柚皮苷对高糖诱导的脐静脉内皮细胞(HUVECs)与单核细胞的粘附的抑制作用及机制。方法分离培养HUVECs后,采用不同剂量的柚皮苷预处理HUVECs,然后高糖诱导HUVECs;加入荧光染料标记单核细胞系THP-1细胞与HUVECs共同孵育,荧光显微镜下观察HUVECs与单核细胞的粘附作用并拍照,比较粘附密度;提取总蛋白后,Western blotting检测处理后HUVECs粘附分子的表达;荧光染料结合法检测处理后HUVECs活性氧的产生;提取处理的脐静脉内皮细胞核蛋白后,Western blotting检测核因子-κB在核内的量。结果高糖诱导HUVECs与单核细胞的粘附,柚皮苷可显著抑制高糖诱导的HUVECs与单核细胞的粘附。柚皮苷抑制高糖诱导的HUVECs细胞间粘附分子和血管内皮细胞粘附分子的表达,柚皮苷抑制高糖诱导的HUVECs活性氧产生,柚皮苷抑制高糖诱导的HUVECs核因子-κBp65活化。结论柚皮苷可能通过抑制高糖诱导的HUVECs活性氧产生,从而抑制核因子-κB的活化,进一步抑制细胞间粘附分子和血管内皮细胞粘附分子的表达,影响HUVECs与THP-1细胞的粘附,从而抑制高糖诱导的血管炎症...     

氧化修饰的低密度脂蛋白对培养的人脐静脉内皮细胞的影响

以培养的人脐静脉内皮细胞(EC)为损伤模型,观察到氧化修饰的低密度脂蛋白(O—LDL,100μg/ml和叔丁基脂氢过氧化物(tbooH,10~(-2)mM)对内皮细胞的硒—谷胱甘肽过氧化物酶(SeGSH—Px)的活性,前列腺环素(PGI_2)的生成,脂质过氧化物(Lpo)含量及SeGSH—Px/Lpo比值有明显的时间依赖效应,即随作用时间的延长,O—LDL和tbooH使EC的SeGSH—Px活性下降,PGI_2生成减少,SeGSH—Px/Lpo比值降低;而Lpo含量则增加。提示O—LDL对EC的损伤实质是脂质过氧化物的作用。     

同型半胱氨酸对内皮细胞单核细胞趋化蛋白-1表达的影响

目的　探讨同型半胱氨酸 (HCY)对内皮细胞中单核细胞趋化蛋白 1 (MCP 1 )表达的影响。方法　使人脐静脉内皮细胞 (HUVECs)暴露于不同浓度的HCY ,孵育 8h后 ,用免疫细胞化学和细胞ELISA方法检测其单核细胞MCP 1的表达。结果　培养的HUVECs能表达单核细胞MCP 1。免疫细胞化学显示 ,0 .1mmol·L- 1 、0 .5mmol·L- 1 和 1mmol·L- 1 HCY组单核细胞MCP 1表达的平均吸光度值分别为 0 .0 789± 0 .0 0 81、0 .0 948± 0 .0 383和 0 .1 1 0 7±0 .0 1 71 ,均显著高于对照组 (0 .0 4 1 1± 0 .0 0 4 6 ,P <0 .0 1 )。细胞ELISA显示 ,上述各实验组单核细胞MCP 1表达的吸光度值分别为 0 .0 4 4 2± 0 .0 0 31、0 .0 4 94± 0 .0 0 39和 0 .0 51 8± 0 .0 0 2 8,对照组为 0 .0 396± 0 .0 0 53 ,方差分析表明 ,各组间均存在显著性差异 (F =58.38,P <0 .0 1 )。结论　培养的HUVECs能低水平表达单核细胞MCP 1 ,HCY能诱导其表达较高水平的单核细胞MCP 1。     

恒磁场对糖基化终产物作用下内皮细胞分泌细胞间黏附分子-1及与单核细胞黏附的影响

目的观察不同强度恒磁场对糖基化终产物(AGE)作用下人脐静脉内皮细胞(HUVEC)分泌细胞间黏附分子-1(ICAM-1)及HUVEC与人单核细胞株THP-1黏附的影响。方法采用体外培养第3代的HUVEC,实验分为6组,即对照组、AGE组(AGE-BSA100μg/L)及AGE+不同强度(1、5、10、20Gs)的恒磁场组。各组细胞于培养及恒磁场作用24h后收集标本,用酶联免疫吸附试验(ELISA)检测HUVEC分泌I-CAM-1的量,计数法观察HUVEC与THP-1的黏附率。结果AGE组细胞ICAM-1的分泌量显著增高(P<0.05vs对照组),而1、5、10和20Gs恒磁场组细胞ICAM-1的分泌量显著低于AGE组(P<0.05)。AGE组HUVEC与THP-1的黏附率显著增加(P<0.05vs对照组),而1、5、10和20Gs恒磁场组HUVEC与THP-1的黏附率显著低于AGE组(P<0.05)。结论1-20Gs的恒磁场可拮抗AGE的作用,抑制HUVEC分泌ICAM-1及与单核细胞的黏附率。     

胍丁胺抑制单核-内皮细胞黏附作用及其机制的研究

目的探讨内源性胍丁胺对氧化低密度脂蛋白（oxidized low density lipoprotein,ox-LDL）诱导的单核-内皮细胞黏附的作用及其可能的机制。方法体外培养人脐静脉内皮细胞（human umbilical vein endothelial cells,HUVEC）,用不同浓度的胍丁胺作用于ox-LDL诱导的HUVEC 24h,加或不加硝基精氨酸甲酯（L-NAME）,观察人单核细胞对HUVEC的黏附及ICAM-1在HUVEC的蛋白表达。结果胍丁胺浓度依赖地抑制ox-LDL诱导的单核细胞对HUVEC的黏附及ICAM-1在HUVEC的表达（P〈0．01）,二者成正相关（r=0．8857,P〈0．001）,加入L-NAME后AGM的作用减弱（P〈0．05）。结论AGM可能通过下调ICAM-1的表达抑制循环单核细胞与内皮细胞的黏附,该作用与一氧化氮合酶（NOS）有关。     

单核细胞趋化蛋白-1诱导人脐静脉内皮细胞的凋亡

目的:研究单核细胞趋化蛋白-1(MCP-1)对人脐静脉内皮细胞(hUVEC)凋亡的影响.方法:培养并鉴定hUVEC;用不同浓度MCP-1(0.1,1.0,10,100μg/L)对其作用24,48h;Annexin V/PI双染细胞,流式细胞仪观察内皮细胞凋亡;琼脂糖凝胶电泳检测细胞染色体"DNA ladder"的形成.结果:MCP-1能诱导hUVEC的凋亡,其效应随浓度和时间的增加而增强(P＜0.01);Annexin V/PI显示凋亡细胞明显增加;细胞DNA呈明显的"DNAladder".结论:MCP-1能诱导hUVEC凋亡.     

低密度及氧化低密度脂蛋白对内皮细胞分泌肾上腺髓质素的影响

目的探讨低密度及氧化低密度脂蛋白对内皮细胞分泌肾上腺髓质素(ADM)的影响.方法利用培养的内皮细胞株ECV-304细胞,分别与不同浓度的低密度(50 100mg/L)、氧化低密度脂蛋白(50 100mg/L)及低密度脂蛋白(50 mg/L) 氧化低密度脂蛋白(50 mg/L)进行孵育,24 h后分别收集培养上清及细胞,用放免分析检测上清及细胞内肾上腺髓质素的含量.结果低密度脂蛋白对肾上腺髓质素的分泌无影响,而氧化型低密度脂蛋白能明显刺激ADM的分泌,二者合用的作用接近于100mg/L的OX-LDL.结论OX-LDL可能具有氧化LDL使其成为OX-LDL的作用,ADM的分泌可能是对细胞损伤的一种反应.     

ox-LDL对PLGF作用内皮细胞释放NO和内皮细胞黏附分子的影响

目的：探讨氧化型低密度脂蛋白对胎盘生长因子-1作用人脐静脉内皮细胞释放一氧化氮和内皮细胞黏附分子的影响。方法：在ox-LDL（25μg／mL）条件下,应用不同浓度的PLGF-1（20、40、80ng／mL）孵育ECV-304,对照组为内皮细胞未受损时,相同浓度梯度的PLGF-1孵育ECV-304,3h、6h、12h、24h后应用ELISA法检测内皮细胞黏附分子-可溶性细胞间黏附因子-1、可溶性血管内皮细胞黏附因子-1的表达,硝酸盐还原酶法检测NO的表达。结果：正常生理条件下,PLGF诱导NO和内皮细胞黏附分子的表达,且呈时间（当t=6h达到最理想的分泌量）、浓度依赖关系。在氧化损伤条件下,PLGF诱导NO的表达下降,而内皮细胞黏附分子的表达则增高,以VCAM-1表达增多更为明显。结论：氧化损伤是动脉粥样硬化的独立危险因素,而PLGF诱导内皮的活化,上调内皮黏附分子的表达,可进一步促使疾病的恶化。故认为抑制PLGF的生物活性可达到控制炎症反应的作用。