oxLDL对人脐静脉内皮细胞通透性影响及机制研究

目的探讨氧化低密度脂蛋白（ox LDL）对人脐静脉内皮细胞（HUVECs）通透性的影响及其可能机制。方法采用Transwell单层细胞模型系统和油红O染色,观察ox LDL对单层血管内皮细胞通透性的影响以及THP-1巨噬细胞内脂质的蓄积情况;采用蛋白质印迹法及免疫荧光技术检测ox LDL对HUVECs紧密连接occludin蛋白的表达及分布改变。结果 ox LDL增加单层内皮细胞对LDL的通透性和THP-1巨噬细胞脂质的蓄积;ox LDL降低occludin蛋白的表达,同时免疫荧光染色显示,ox LDL处理后,血管内皮细胞间隙增宽,occludin染色减少或脱失,而抑制氧化应激可以减弱ox LDL对内皮细胞的高通透性反应和occludin蛋白表达和形态学的影响。结论 ox LDL可能是通过occludin蛋白表达下降使内皮细胞构改变来介导内皮通透性增加,从而促进内皮下巨噬细胞内的脂质蓄积。     

Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ~ 6500 unique proteins quantified, ~ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content.     

Protein kinase C isoforms in atherosclerosis: Pro- or anti-inflammatory?

Atherosclerosis is a pathologic condition caused by chronic inflammation in response to lipid deposition in the arterial wall. There are many known contributing factors such as long-term abnormal glucose levels, smoking, hypertension, and hyperlipidemia. Under the influence of such factors, immune and non-immune effectors cells are activated and participate during the progression of atherosclerosis. Protein kinase C (PKC) family isoforms are key players in the signal transduction pathways of cellular activation and have been associated with several aspects of the atherosclerotic vascular disease. This review article summarizes the current knowledge of PKC isoforms functions during atherogenesis, and addresses differential roles and disputable observations of PKC isoforms. Among PKC isoforms, both PKCβ and PKCδ are the most attractive and potential therapeutic targets. This commentary discusses in detail the outcomes and current status of clinical trials on PKCβ and PKCδ inhibitors in atherosclerosis-associated disorders like diabetes and myocardial infarction. The risk and benefit of these inhibitors for clinical purposes will be also discussed. This review summarizes what is already being done and what else needs to be done in further targeting PKC isoforms, especially PKCβ and PKCδ, for therapy of atherosclerosis and atherosclerosis-associated vasculopathies in the future.     

Antrodia salmonea in submerged culture exhibits antioxidant activities in vitro and protects human erythrocytes and low-density lipoproteins from oxidative modification

Antrodia salmonea is well known in Taiwan as a beneficial mushroom. In the present study, we investigated the antioxidant activity of whole fermented broth (AS), filtrate (ASF), and mycelia (ASM) of A. salmonea using different antioxidant models. Furthermore, the effect of A. salmonea on AAPH-induced oxidative hemolysis of human erythrocytes and CuSO₄-induced oxidative modification of human low-density lipoproteins (LDLs) was examined. We found that the AS, ASF, and ASM possess effective antioxidant activity against various oxidative systems including superoxide anion scavenging, reducing power, metal chelation, and DPPH radical scavenging. Further, AAPH-induced oxidative hemolysis in erythrocytes was prevented by AS, ASF, and ASM. Notably, AS, ASF, and ASM appear to possess powerful antioxidant activities against CuSO₄-induced oxidative modification of LDL as assessed by malondialdehyde (MDA) formation, cholesterol degradation, and the relative electrophoretic mobility of oxidized LDL. It is noteworthy that AS had comparatively strong antioxidant ability compared to ASF or ASM, which is well correlated with the content of their total polyphenols. Thus, A. salmonea may exert antioxidant properties and offer protection from atherogenesis.     

Oxidation-specific epitopes are important targets of innate immunity

During the oxidation of LDL, a central pathophysiological component of atherogenesis, a wide variety of chemical and physical changes occur leading to the generation of oxidation-specific neoepitopes. These epitopes are not only immunogenic, leading to adaptive humoral responses, but are also a prominent target of multiple arcs of innate immunity. The pattern recognition receptors (PRRs) of innate immunity are germ line encoded, conserved by natural selection, and bind to pathogen-associated molecular patterns (PAMPs) common on multiple structures. However, it is not intuitive as to why they should recognize oxidation-specific neoepitopes. Yet it is clear that multiple macrophage scavenger receptors, which are classic PRRs, recognize oxidation-specific epitopes, such as those found on oxidized LDL (OxLDL). Other innate proteins, such as C-reactive protein, also bind to OxLDL. Natural antibodies (NAbs), the humoral arc of innate immunity, provide a nonredundant role in the first line of defence against pathogens, but are also believed to provide important homeostatic house-keeping functions against self-antigens. Our work demonstrates that oxidation-specific epitopes, as found on OxLDL, are a major target of NAbs. In this review, we will discuss the specific example of the prototypic NAb T15/E06, which is increased in atherosclerotic mice and mediates atheroprotection, and discuss the potential role of NAbs in atherogenesis, and in inflammation in general. We also review data that oxidation-specific epitopes are generated whenever cells undergo programmed cell death, forming a common set of PAMPs recognized by oxidation-specific PRRs on macrophages, NAbs and innate proteins. We present the hypothesis that oxidation-specific epitopes on apoptotic cells exerted evolutionary pressure for the conservation of these PRRs and also serve to maintain the expansion of a substantial proportion of NAbs directed to these stress-induced self-antigens.     

糖尿病患者Apo－Al、Apo－B测定及其临床意义

本文对６０例糖尿病患者及６２例正常人的血清载脂蛋白（Ａｐｏ）－Ａｌ，Ａｐｏ－Ｂ高密度脂蛋白（ＨＤＬ）和低密度脂蛋白（ＬＤＬ）水平进行了测定，结果显示：（１）糖尿病患者Ａｐｏ－Ａｌ水平和Ａｐｏ－Ｂ水平均明显高于正常人（Ｐ＜０．０１）。（２）住院治疗前，糖尿病患者血清ＨＤＬ水平明显低于正常人（Ｐ＜０．０１）。（３）住院治疗期间糖尿病患者血清ＨＤＬ水平显著增高（Ｐ＜０．０１），而ＬＤＬ水平无明显改变（Ｐ＞０．０５）。     

The contribution of ApoB and ApoA1 measurements to cardiovascular risk assessment

LDL has been widely recognized as the major atherogenic lipoprotein and designated as the primary target for prevention of coronary heart disease (CHD); however, there is growing evidence that other triglyceride-rich lipoproteins, such as very low-density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) carry atherogenic potential as well. This led to the designation of non-HDL cholesterol (HDL-C) (LDL + IDL + VLDL) as a secondary target of treatment for hyperlipidaemia. As each one of LDL, IDL and VLDL particles carries only one apolipoprotein B-100 (ApoB-100) molecule, the total ApoB value represents the total number of potentially atherogenic lipoproteins, whereas non-HDL-C provides the cholesterol content of these same lipoproteins. Recent data from epidemiological, observational and interventional studies suggest that non-HDL-C, apolipoproteins ApoA1 and ApoB may improve CHD risk assessment by identifying more high-risk individuals than the usual lipid profile alone. However, the targets for the optimal treatment of dyslipidaemia remain a subject of considerable debate. Further studies are needed to determine whether ApoB and ApoA1 are superior to conventional lipid parameters as predictors of cardiovascular disease or therapeutic targets of hyperlipidaemias. In this review, we summarize the current opinions on the use of ApoA1 and ApoB values as estimates of cardiovascular risk or as treatment goals in patients undergoing treatment for hyperlipidaemia.     

低密度脂蛋白受体基因NcoI多态性与老年人心肌梗死的关系

目的探讨低密度脂蛋白受体基因(LDLR)NcoI多态性与心肌梗死(MI)的相关性,并对其与血脂的关系进行分析。方法用聚合酶链反应(PCR)技术检测102例辽宁藉汉族健康人和84例老年MI患者的LDLR基因NcoI多态性及含量。结果LDLR基因NcoI等位基因频率健康人N+为0.667,MI组基因N+为0.768,MI组比对照组明显增高(P<0.05);血清TC、LDLC、TG及LP(a)水平亦明显增高(P<0.05)。结论NcoI多态性的N+型等位基因与MI的发生密切相关。     

Metabolic syndrome and associated factors among psychiatric patients in Jimma University Specialized Hospital,South West Ethiopia

Background

Metabolic syndrome is a multisystem disorder which coined to describe the recognized clustering of metabolic and cardiovascular abnormalities including obesity, hypertension, dyslipidemia, and abnormalities of glucose homeostasis.