凝集素样氧化低密度脂蛋白受体-1介导氧化低密度脂蛋白促进血管平滑肌细胞血管紧张素转化酶的表达

目的:观察氧化低密度脂蛋白(ox-LDL)对血管平滑肌细胞(VSMC)血管紧张素转化酶(ACE)表达的影响及凝集素样氧化低密度脂蛋白受体-1(LOX-1)在其中的作用。方法:人脐带动脉平滑肌细胞体外原代培养,传至4~5代用于实验。ox-LDL干预,RT-PCR测定VSMC ACE mRNA和LOX-1mRNA表达。并观察予以LOX-1的抑制剂多聚肌苷酸作用后,VSMC ACE mRNA表达的变化。结果:①较高浓度ox-LDL(20mg/L,100mg/L)作用后,VSMC ACE mRNA表达升高,作用1h出现峰值。低浓度ox-LDL(10mg/L)此种作用不明显。②ox-LDL作用后,VSMCLOX-1 mRNA表达升高,且随着ox-LDL浓度的升高而表达增强。③多聚肌苷酸抑制LOX-1后,ACE mRNA表达明显下降。结论:ox-LDL明显促进VSMC ACE表达,LOX-1在此过程中起重要介导作用。     

氧化型低密度脂蛋白诱导肝窦内皮细胞植物血凝素样氧化型低密度脂蛋白受体1的表达

目的：探讨植物血凝素样氧化型低密度脂蛋白（ox-LDL）受体1（LOX-1）在肝窦内皮细胞（HSECs）中的表达和ox-LDL对其表达的调控作用。方法使用实时定量聚合酶链反应（RT-PCR）和Western blotting法从基因和蛋白水平检测未经处理HSECs 中LOX-1的表达。应用不同浓度ox-LDL（0、20、40、60、80和100 mg/L）对HSECs作用24 h并应用80 mg/L ox-LDL对HSECs作用不同时间（0、12、24和48 h）,作用后实时定量PCR检测HSECs内LOX-1 mRNA的表达水平,Western blotting法检测细胞内LOX-1蛋白表达。给予80 mg/L ox-LDL干预组多聚肌苷酸250 mg/L作用24 h后,测定LOX-1 mRNA和蛋白的表达。采用单因素方差分析及t检验进行数据分析。结果 LOX-1 mRNA和蛋白在HSECs中均有表达。20～80 mg/L ox-LDL组HSECs中LOX-1 mRNA、蛋白表达水平随ox-LDL剂量增加而升高,与剂量有明显相关性（F＝38.7、3.43,均P＜0.05）。与80 mg/L ox-LDL组相比,100 mg/L ox-LDL 组 LOX-1 mRNA、蛋白表达下降,差异有统计学意义（ t ＝23.75、18.26, P ＜0.05）。80 mg/L ox-LDL对HSECs作用时间在0～24 h时,随着时间延长,LOX-1 mRNA、蛋白表达递增,与ox-LDL作用时间有明显相关性（F＝2.36、0.33,均P＜0.05）。与作用24 h相比,作用48 h组HSECs中LOX-1 mRNA、蛋白表达下降（t＝69.21、36.27,均P＜0.05）。与80 mg/L ox-LDL组相比,多聚肌苷酸组中LOX-1 mRNA和蛋白表达降低,两组差异均有统计学意义（ t＝54.93、28.19,均P＜0.05）。结论LOX-1存在于HSECs。在一定浓度和时间范围内,ox-LDL对HSECs LOX-1的调控作用具有时间和浓度依赖性,而多聚肌苷酸可部分抑制这种效应。     

LOX-1在ox-LDL诱导血管平滑肌细胞表达Fractalkine中的作用及罗布麻的干预

目的:研究血凝素样氧化低密度脂蛋白受体-1(LOX-1)在氧化型低密度脂蛋白(ox-LDL)诱导血管平滑肌细胞(VSMC)表达不规则趋化因子(FKN)中的角色及罗布麻的干预作用.方法:用组织贴块培养法培养大鼠VSMC,应用ELISA法检测LOX-1蛋白表达、RT-PCR法检测FKN mRNA的表达.结果:ox-LDL可诱导大鼠VSMS高表达FKN,分别应用LOX-1的阻断剂角叉菜胶和罗布麻后,FKN的表达均明显下降(P<0.05).结论:在VSMC的炎症反应中,ox-LDL通过LOX-1途径激活了FKN的表达,高浓度罗布麻(0.8 g/L)可抑制FKN的表达,推测罗布麻可能起到抗炎、抗动脉粥样硬化的作用.     

Lox-1受体介导ox-LDL促进血管平滑肌细胞MMP-9mRNA表达

目的 :观察氧化低密度脂蛋白 (ox LDL)对血管平滑肌细胞 (VSMC)基质金属蛋白酶 9(MMP 9)表达的影响及凝集素样氧化低密度脂蛋白受体 1(Lox 1)在其中的作用。方法 :人脐带动脉平滑肌细胞体外原代培养 ,传至 4～ 5代用于实验。ox LDL干预 ,RT PCR测定VSMCMMP 9RNA和Lox 1mRNA表达。并观察予以Lox 1的抑制剂多聚肌苷酸作用后 ,VSMCMMP 9mRNA的表达的变化。结果 :①ox LDL作用后 ,VSMCMMP 9mRNA表达升高 ,P <0 .0 1,作用 1h出现峰值。ox LDL浓度升高 ,MMP 9mRNA表达增强。②ox LDL作用后 ,VSMCLox 1mRNA表达升高 ,且随着ox LDL浓度的升高有升高趋势 ,均P <0 .0 1。③多聚肌苷酸抑制Lox 1后 ,MMP 9mRNA表达明显下降 ,P <0 .0 1。结论 :ox LDL明显促进VSMCMMP 9表达 ,Lox 1在此过程中起重要介导作用     

人单核细胞Lox-1对MMP-9、TIMP-1mRNA表达的调控作用

目的 探讨氧化低密度脂蛋白(ox-LDL)对人单核细胞基质金属蛋白酶-9(MMP-9)、组织金属蛋白酶抑制物-1(TIMP-1)mRNA表达调控的机制,以及血凝素样氧化低密度脂蛋白受体-1(Lox-1)在其表达调控中的作用.方法 分离收集冠心病患者的外周血单核细胞,分为空白对照组(在不含血清的RPMI-1640中孵育24 h)、ox-LDL组(在不含血清的RPMI-1640中加ox-LDL 40 μg/ml孵育24 h)、多聚肌苷酸(PIA)组(在不含血清的RPMI-1640中先加PIA 250 μg/ml培育1 h,之后加入ox-LDL 40 μg/ml继续孵育24 h).收集单核细胞及细胞上清液,采用异硫氰酸胍-酚-氯仿抽提法提取总RNA,扩增目的 基因Lox-1、MMP-9、TIMP-1mRNA,并采用ELISA法测定上清液中sLox-1、MMP-9、TIMP-1浓度.结果 单核细胞经ox-LDL刺激后Lox-1、MMP-9 mRNA表达增加(0.813±0.131 vs 0.304±0.047,P＜0.01;1.130±0.089 vs 0.595±0.091,P＜0.01),细胞上清液中sLox-1、MMP9蛋白含量增加(16.517±2.064 vs 7.277±1.979,P＜0.01;2.213±1.071 vs 0.967±0.500,P＜0.01).与ox-LDL组相比,多聚肌苷酸预刺激后单核细胞Lox-1、MMP-9 mRNA表达减少(0.277±0.029 vs 0.813±0.131,P＜0.01;0.715±0.286 vs 1.130±0.089,P＜0.05),细胞上清液中sLox-1、MMP9蛋白含量显著减少(11.127±2.560 vs 16.517±2.064,P＜0.05;1.040±0.312 vs 2.213±1.071,P＜0.05),但与对照组比较无差异.TIMP-1 mRNA表达及细胞上清液中TIMP-1蛋白含量在各组间无显著差异.结论 ox-LDL可诱导人单核细胞Lox-1、MMP-9表达增加,并且Lox-1介导了ox-LDL对MMP-9表达的促进作用,但对TIMP-1表达无影响.     

氨氯地平对冠心病患者外周血单核细胞血凝素样氧化低密度脂蛋白受体-1表达的影响

目的:观察氨氯地平对单核细胞血凝素样氧化低密度脂蛋白受体-1(Lox-1)表达的影响,以探讨氨氯地平能否稳定斑块及其可能的机制.方法:分离收集冠心病患者的外周血单核细胞,分为3组:空白对照组、氧化低密度脂蛋白(ox-LDL)组、氨氯地平组并给予不同的处理,之后收集单核细胞及细胞上清液,采用异硫氰酸胍-酚-氯仿抽提法提取总RNA,扩增目的基因Lox-1、基质金属蛋白酶-9(MMP-9)、TIMP-1mRNA,并测定细胞上清液中sLox-1、MMP-9、组织金属蛋白酶抑制物-1(TIMP-1)浓度.结果:氨氯地平组单核细胞Lox-1mRNA的表达与ox-LDL组相比明显减少(P<0.01),与空白对照组相比无差异;而MMP-9 mRNA的表达与ox-LDL组及空白对照组相比均明显减少(P<0.01);但TIMP-1 mRNA的表达与ox-LDL组及空白对照组相比均无差异;氨氯地平组细胞上清液中sLox-1的蛋白含量与ox-LDL组相比明显减少(P<0.01),与空白对照组比无差异;MMP-9的蛋白含量与ox-LDL组及空白对照组相比均减少(P<0.01,P<0.05);TIMP-1的蛋白含量与ox-LDL组及空白对照组相比均无差异.结论:氨氯地平可抑制单核细胞Lox-1、MMP-9的表达,从而起到稳定斑块的作用.     

LOX-1mRNA在急性冠脉综合征患者外周血单核细胞的表达

目的 探讨外周血单核细胞血凝素样氧化低密度脂蛋白受体-1(LOX-1)mRNA表达与急性冠脉综合征(acute coronary syndrome,ACS)间的关系.方法 分离8例ACS、8例稳定性心绞痛(SAP)及8例对照(C)外周血单核细胞,采用异硫氰酸胍-酚-氯仿抽提法提取总RNA,扩增目的 基因LOX-1mRNA.结果 ACS患者外周血单核细胞LOX-1mRNA表达与C组比较增加(P＜0.05),且血清氧化低密度脂蛋白(ox-LDL)浓度与C组比较亦增高(P＜0.05);单核细胞LOX-1mRNA表达与血清ox-LDL浓度呈正相关(r=0.527,P=0.008);而与冠脉狭窄积分无相关性.结论 ACS患者外周血单核细胞LOX-1mRNA表达增加,可能参与ACS的发病过程.     

ox-LDL促进树突状细胞LOX-1表达及炎症因子分泌

目的应用小鼠高脂模型及树突状细胞株研究血凝素样氧化型低密度脂蛋白受体1(LOX-1)高表达树突状细胞(DC)在动脉粥样硬化中的作用。方法氧化型低密度脂蛋白(ox-LDL)诱导原代培养的C57小鼠骨髓来源的树突状细胞(BMDC),采用Western blot检测BMDC LOX-1蛋白水平;采用流式细胞术检测高表达LOX-1和低表达LOX-1细胞亚群的比例;MACS磁珠分选LOX-1表达水平不同的两种细胞亚群,观察ox-LDL对两种细胞亚群的影响及释放炎症因子的影响;采用C57小鼠高脂模型,在高脂喂养的不同时间(4周、6周、8周)检测小鼠总胆固醇水平和主动脉中DC数量;用不同浓度的Dil标记的ox-LDL(Dil-ox-LDL)刺激DC2.4细胞,荧光显微镜观察各组细胞吞噬作用的差异,Western blot检测LOX-1的表达。结果 DC可分为高表达和低表达LOX-1两种细胞亚群,且ox-LDL能增加LOX-1~(high)DC的比例;分选后的阳性细胞被ox-LDL刺激后,TNF-α和IL-1βmRNA的表达明显上调(P0.01),且阳性细胞的上升比例高于阴性细胞。在C57小鼠高脂模型中,高脂喂养组总胆固醇水平明显升高,且随着总胆固醇水平的升高,小鼠主动脉中DC增多,且LOX-1~(high)DC比例明显增加。用不同浓度的Dil-ox-LDL刺激DC2.4细胞,随着Dil-ox-LDL浓度的升高,DC2.4细胞对ox-LDL的吞噬也增加,并且ox-LDL可以诱导DC2.4细胞表面LOX-1表达,20 mg/L和40 mg/L的ox-LDL对LOX-1表达的诱导作用明显。结论 ox-LDL能够上调DC表面受体LOX-1,增加LOX-1~(high)DC比例,促进炎症因子表达。     

血凝素样氧化低密度脂蛋白受体-1

血凝素样氧化低密度脂蛋白受体-1(LOX-1)是内皮细胞摄取氧化低密度脂蛋白(ox-LDL)的特异性受体.高脂血症、氧化应激等多种因素可以促进LOX-1的表达.LOX-1表达通过诱导各种黏附分子和炎症因子的表达、激活蛋白激酶、诱导细胞凋亡等途径促进平滑肌细胞和巨噬细胞吞噬脂质,并转化为泡沫细胞,促进动脉粥样硬化斑块的形成.     

血凝素样氧化型低密度脂蛋白受体1介导氧化型低密度脂蛋白促进血管平滑肌细胞表达白细胞介素6

观察氧化型低密度脂蛋白对血管平滑肌细胞白细胞介素 6表达的影响及血凝素样氧化型低密度脂蛋白受体 1在其中的作用。人脐带动脉平滑肌细胞体外原代培养 ,传至 4～ 5代。氧化型低密度脂蛋白干预 ,观察不同时间点白细胞介素 6mRNA表达 ,及不同浓度氧化型低密度脂蛋白对白细胞介素 6和血凝素样氧化型低密度脂蛋白受体 1mRNA表达的影响。并观察血凝素样氧化型低密度脂蛋白受体 1抑制剂多聚肌酐酸对白细胞介素 6mRNA表达的影响。结果发现 ,(1)氧化型低密度脂蛋白作用后 ,白细胞介素 6mRNA表达显著升高 ,作用 6h出现峰值。随着氧化型低密度脂蛋白浓度升高 ,白细胞介素 6mRNA和血凝素样氧化型低密度脂蛋白受体 1mRNA表达均明显升高 ,后两者呈正相关 (r=0 .94 3,P <0 .0 1)。 (2 )多聚肌酐酸抑制血凝素样氧化型低密度脂蛋白受体 1后 ,白细胞介素 6mRNA表达明显下降。以上表明氧化型低密度脂蛋白明显促进血管平滑肌细胞白细胞介素 6的表达 ,血凝素样氧化型低密度脂蛋白受体 1在此过程中起重要介导作用。     

Cytochrome 1A1 and 1B1 gene diversity in the Zanzibar islands

Amodiaquine (AQ) is a 4‐aminoquinoline widely used in the treatment of malaria as part of the artemisinin combination therapy (ACT). AQ is metabolised towards its main metabolite desethylamodiaquine mainly by cytochrome P450 2C8 (CYP2C8). CYP1A1 and CYP1B1 play a minor role in the metabolism but they seem to be significantly involved in the formation of the short‐lived quinine‐imine. To complete the genetic variation picture of the main genes involved in AQ metabolism in the Zanzibar population, previously characterised for CYP2C8, we analysed in this study CYP1A1 and CYP1B1 main genetic polymorphisms. The results obtained show a low frequency of the CYP1A1*2B/C allele (2.4%) and a high frequency of CYP1B1*6 (approximately 42%) followed by CYP1B1*2 (approximately 27%) in Zanzibar islands. Genotype data for CYP1A1 and CYP1B1 show a low incidence of fast metabolisers, revealing a relatively safe genetic background in Zanzibar’s population regarding the appearance of adverse effects.     

CYP1A1 , GSTM1 , GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men

AIM: To investigate the role of functional genetic poly-morphisms of metabolic enzymes of tobacco carcinogens in the development of colorectal adenomas. METHODS: The study subjects were 455 patients with colorectal adenomas and 1052 controls with no polyps who underwent total colonoscopy in a preretirement health examination at two Self Defense Forces hospitals. The genetic polymorphisms studied wereCYP1A1*2A (rs 4646903), CYP1A1*2C (rs 1048943), GSTM1 (null or non-null genotype), GSTT1 (null or non-null genotype) and NQO1 C609T (rs 1800566). Genotypes were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR method using genomic DNA extracted from the buffy coat. Cigarette smoking and other life-style factors were ascertained by a self-administered questionnaire. The associations of the polymorphisms with colorectal adenomas were examined by means of OR and 95%CI, which were derived from logistic regression analysis. Statistical adjustment was made for smoking, alcohol use, body mass index and other factors. The gene-gene interaction and effect modification of smoking were evaluated by the likelihood ratio test. RESULTS: None of the five polymorphisms showed a significant association with colorectal adenomas, nor was the combination of GSTM1 and GSTT1 . A borderline significant interaction was observed for the combination of CYP1A1*2C and NQO1 (P = 0.051). The OR associated with CYP1A1*2C was significantly lower than unity among individuals with the NQO1 609CC genotype. The adjusted OR for the combination of the CYP1A1*2C allele and NQO1 609CC genotype was 0.61 (95%CI: 0.42-0.91). Although the interaction was not statistically significant (P = 0.24), the OR for individuals carrying the CYP1A1*2C allele and GSTT1 null genotype decreased significantly compared with those who had neither CYP1A1*2C allele nor GSTT1 null genotype (adjusted OR: 0.69, 95%CI: 0.49-0.97). Smoking did not modify the associations of the individual polymorphisms with colorectal adenomas. There w     

Inhibition of procarcinogen-bioactivating human CYP1A1, CYP1A2 and CYP1B1 enzymes by melatonin

Abstract:  Administration of melatonin to rodents decreases the incidence of tumorigenesis initiated by benzo[ a ]pyrene or 7,12-dimethylbenz[ a ]anthracene, which requires bioactivation by cytochrome P450 enzymes, such as CYP1A1, CYP1A2 and CYP1B1, to produce carcinogenic metabolites. The present study tested the hypothesis that melatonin is a modulator of human CYP1 catalytic activity and gene expression. As a comparison, we also investigated the effect of melatonin on the catalytic activity of CYP2A6, which is also a procarcinogen-bioactivating enzyme. Melatonin (3–300 μ m ) decreased 7-ethoxyresorufin O -dealkylation catalyzed by human hepatic microsomes and recombinant CYP1A1, CYP1A2 and CYP1B1, whereas it did not affect coumarin 7-hydroxylation catalyzed by hepatic microsomes or recombinant CYP2A6. Melatonin inhibited CYP1 enzymes by mixed inhibition, with apparent K _i values (mean ± S.E.M.) of 59 ± 1 (CYP1A1), 12 ± 1 (CYP1A2), 14 ± 2 (CYP1B1) and 46 ± 8 μ m (hepatic microsomes). Additional experiments indicated that melatonin decreased benzo[ a ]pyrene hydroxylation catalyzed by hepatic microsomes and CYP1A2 but not by CYP1A1 or CYP1B1. Treatment of MCF-10A human mammary epithelial cells with melatonin (up to 300 μ m ) did not affect basal or benzo[ a ]pyrene-inducible CYP1A1 or CYP1B1 gene expression. Consistent with this finding, melatonin did not influence reporter activity in aryl hydrocarbon receptor-dependent pGudluc6.1-transfected MCF-10A cells treated with or without benzo[ a ]pyrene, as assessed in an in vitro cell-based luciferase reporter gene assay. Overall, melatonin is an in vitro inhibitor of human CYP1 catalytic activity, and it may be useful to develop potent analogues of melatonin as potential cancer chemopreventive agents that block CYP1-mediated chemical carcinogenesis.     

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1)

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.     

Interleukin 1 (IL 1)

Interleukin 1 is an essential factor of macrophage dependent T cell activation and has a large quantity of other biological activities. This paper gives a review of present knowledge of Interleukin 1. In addition to biochemical properties, the IL 1 production and IL 1 activities, methods for determining of IL 1 and inhibitory factors of IL 1 induced T cell proliferation are described.     

Pandemic H1N1 influenza

The 2009 H1N1 influenza A virus that has targeted not only those with chronic medical illness, the very young and old, but also a large segment of the patient population that has previously been afforded relative protection - those who are young, generally healthy, and immune naive. The illness is mild in most, but results in hospitalization and severe ARDS in an important minority. Among those who become critically ill, 20-40% will die, predominantly of severe hypoxic respiratory failure. However, and potentially in part due to the young age of those affected, intensive care with aggressive oxygenation support will allow most people to recover. The volume of patients infected and with critical illness placed substantial strain on the capacity of the health care system and critical care most specifically. Despite this, the 2009 pandemic has engaged our specialty and highlighted its importance like no other. Thus far, the national and global critical care response has been brisk, collaborative and helpful - not only for this pandemic, but for subsequent challenges in years ahead.