橙皮苷对小鼠急性肝衰竭的保护作用及其机制

目的观察橙皮苷对脂多糖(Lipopolysaccharide,LPS)联合D-氨基半乳糖(D-Galactosamine,D-GalN)所致小鼠急性肝衰竭(Acute hepatic failure,AHF)的保护作用及其机制。方法小鼠腹腔注射LPS(50μg/kg)和D-GalN(800 mg/kg),复制急性肝衰竭模型,分别用橙皮苷(200 mg/kg)或橙皮苷(200 mg/kg)联合锌原卟啉IX(Zinc protoporphyrin IX,ZnPP)(45 mg/kg)干预。造模后6 h检测肝损伤程度和炎症反应强度,48 h统计小鼠死亡率。结果橙皮苷使AHF小鼠血清转氨酶(ALT和AST)水平下降,肝损伤减轻,生存率提高;血清白细胞介素-10(Interleukin-10,IL-10)水平和肝内血红素加氧酶-1(Heme oxygenase-1,HO-1)的表达较AHF小鼠明显增加,肝内HO-1酶活性明显增高;同时,使血清肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)水平、肝组织中Caspase-3蛋白酶和髓过氧物酶(Myeloperoxidase,MPO)活性较AHF小鼠明显降低。ZnPP不影响橙皮苷促进肝内HO-1酶表达,但通过抑制HO-1酶活性,使橙皮苷抗炎和肝损伤保护作用显著降低。结论橙皮苷主要通过诱导HO-1蛋白表达,使HO-1酶活性增强,从而使炎症反应和肝损伤减轻,对LPS联合D-GalN诱导的AHF产生保护作用。     

陈皮中橙皮苷的提取工艺及优化研究

主要分析研究乙醇-吡啶混合溶剂超声浸提法提取陈皮中橙皮苷的最优条件。通过单因素试验去分析研究不同种因素对橙皮苷提取率的影响,并且在此基础上根据优化后的结果进行正交试验。其最佳工艺条件为料液比1:30,吡啶比例25%,提取温度为85℃,提取时间为25 min。采用该条件处理的橙皮苷经高效液相色谱法进行橙皮苷含量的测定,同时在此等优化条件下进行的正交试验,橙皮苷的提取率为3.83%,超声浸提法操作简便,快速,成本低,能应用于工业化生产和医学医药类研究。     

咪唑酪氨酸离子液体对橘皮橙皮苷的提取

为了寻求一种新型有效溶剂提取橘皮橙皮苷,采用两步法制备了1-己基-3-甲基咪唑酪氨酸离子液体并用于提取橘皮橙皮苷。结果发现：离子液体的制备产率高达75%,提取温度、提取时间、液固比、离子液体浓度对橙皮苷提取率都有显著影响;单因素实验优化得到该离子液体对橘皮橙皮苷提取的最优条件为温度50℃,离子液体浓度40%,液固比16,提取时间90 min,橙皮苷的提取率为4.7%,抗溶剂稀释倍数为10时,橙皮苷提取物的纯度为62%。     

淋巴细胞功能相关抗原-1基因敲除对实验性自身免疫性脑脊髓炎小鼠引流淋巴结T细胞活性的影响

目的探讨淋巴细胞功能相关抗原-1(lymphocyte function-associated antigen-1,LFA-1)基因敲除对实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)模型小鼠引流淋巴结T细胞活性的影响。方法采用髓鞘少突胶质细胞糖蛋白(myelin oligodendrocyte glycoprotein,MOG)35-55多肽诱导LFA-1a链CD11a基因敲除的C57BL/6小鼠及野生型C57BL/6小鼠,建立EAE小鼠模型,取MOG诱导后21 d EAE模型小鼠脊髓颈段切片,HE染色和LuxolFastBlue染色,观察小鼠脊髓组织学变化;于MOG诱导后7、14、21d处死小鼠,收集腹股沟引流淋巴结CD4+T淋巴细胞,加入终浓度为1μg/ml的MOG35-55多肽刺激48 h后,应用BrdU试剂盒检测细胞增殖情况;于MOG诱导后4、7、10、14、21 d处死小鼠,收集腹股沟引流淋巴结细胞,加入终浓度为1μg/ml的MOG35-55多肽刺激48 h后,进行细胞内细胞因子染色,观察分泌IFNγ和IL-17的T细胞比例。结果 MOG诱导的野生型小鼠脊髓出现明显淋巴细胞浸润及广泛的脱髓鞘变化,而LFA-1基因敲除小鼠无明显变化;在EAE疾病早期(7 d),LFA-1基因敲除可减少淋巴细胞向引流淋巴结聚集,降低MOG体外刺激T细胞增殖能力,分泌IFNγ及IL-17的T细胞比例也较野生型C57BL/6小鼠明显降低(P0.05);而在EAE疾病缓解期(21 d),LFA-1基因敲除小鼠淋巴细胞聚集及T细胞增殖能力与野生型C57BL/6小鼠相比无明显差异(P0.05),分泌IFNγ及IL-17的T细胞比例高于野生型C57BL/6小鼠(P0.05)。结论在EAE疾病发生早期,LFA-1可能起到了关键性的作用,LFA-1有可能成为自身免疫性疾病治疗的重要分子靶点。     

动脉粥样硬化疫苗的研究进展

动脉粥样硬化 (Atherosclerosis ,AS)是一种血管疾病 ,它以血管平滑肌细胞增生和血脂在粥样硬化斑块沉积为特征。粥样斑块的形成与脂代谢紊乱、低密度脂蛋白 (LDL)、胆固醇酯转运蛋白 (CETP)、CD4 0 CD4 0配体及肺炎衣原体 (Cpn)感染等多种因素有关。目前 ,有些药物虽有一定疗效 ,但仅仅是暂时抑制AS病情的发展 ,不能有效治疗AS ,所以研制LDL疫苗、CETP疫苗、CD4 0疫苗、Cpn疫苗等是非常有效的手段 ,将有助于抑制动脉硬化的发生与发展 ,减少这些疾病对人类的危害。     

醛脱氢酶基因敲除对克氏肺炎杆菌合成1，3-丙二醇的影响

利用Klebsiella pneumoniae厌氧发酵甘油生产1,3-丙二醇时，一部分甘油通过氧化代谢途径大量合成副产物乙醇，降低了1,3-丙二醇的得率.醛脱氢酶ALDH是乙醇合成途径的关键酶之一，其催化作用不仅消耗了大量甘油，还将还原型辅酶NADH氧化为NAD⁺，降低了同为NADH依赖型的1,3-PD合成途径的效率.本文以醛脱氢酶ALDH为改造目标，以K.pneumoniae为宿主，通过同源重组技术在K.pneumoniae M5aL的ALDH基因中成功地插入了四环素抗性基因，经抗性筛选和基因水平鉴定，得到两株ALDH基因敲除的重组菌0623-1hb及0623-1hc.本文研究了这两株重组菌的生长代谢特性，结果表明两株重组菌的ALDH酶活基本检测不到，菌体生长受到明显抑制，乙醇合成浓度比出发菌株K.pneumoniae M5aL降低了43%～53%，1,3-PD合成浓度及摩尔得率分别提高了27%～42%和19%～24%.     

pgi基因敲除对大肠杆菌利用混合碳源的影响

木质纤维素是地球上最丰富的碳源,可广泛应用于生物燃料和生物化工。但是由于分解代谢阻遏,不能完全利用木质纤维素降解产物中获得的多种糖类,严重制约了木质纤维素的商业应用。研究主要构建了一株可以同时消耗葡萄糖、果糖、木糖的菌株E.coli BW25113△pgi,并探讨了其分别在好氧和厌氧条件下以葡萄糖、果糖、木糖为混合碳源时的碳源利用情况。敲除pgi后,葡萄糖、果糖、木糖三种糖被同时消耗。研究通过发酵数据、基因转录水平数据和代谢流分析数据阐述了敲除pgi解除分解代谢阻遏的机理。pgi基因的敲除导致pts G转录水平下降,增加了c AMP-Crp的含量,从而解除分解代谢阻遏,实现了混合碳源的共利用,为木质纤维素的开发利用提供了新的思路。     

人血高密度脂蛋白对家兔实验性动脉粥样硬化疾病的预防和治疗

从人血中提取的高密度脂蛋白(?)能使已形成动脉硬化斑块的家兔血管壁恢复正常。静脉注射28mg 高密度脂蛋白,使动脉粥样硬化家兔血清总胆固醇量下降15.8%,沉积到血管壁上的~3H 胆固醇释放到血流中并被清除。家兔喂高胆固醇饲料73天后形成动脉粥样硬化斑块,面积占动脉总面积的15%,同时注射高密度脂蛋白(759mg)的家兔,斑块面积只占动脉总面积的1.6%。已形成硬化斑块的家兔不予处理,36天后斑块面积为68.8%,在此期间注射高密度脂蛋白之家兔,斑块面积为0%,试验结果提示高密度脂蛋白能预防和治疗实验性家兔动脉粥样硬化。     

CXCL4基因敲除小鼠的饲养、繁殖及基因型鉴定

目的饲养、繁殖并鉴定CXC趋化因子配体4[chemokine(C-X-C motif)ligand 4,CXCL4]基因敲除小鼠,为深入研究CXCL4的生物学功能奠定基础。方法将引进的杂合子小鼠进行饲养并繁殖,剪取繁殖成功的子代小鼠耳朵,提取其基因组DNA,采用PCR法鉴定小鼠的基因型;比较野生型小鼠和CXCL4敲除的纯合子小鼠的体重变化及结直肠的长度,通过HE染色观察野生型小鼠和CXCL4敲除的纯合子小鼠的结直肠形态结构;采用ELISA法验证CXCL4野生型和纯合子小鼠血清中CXCL4的表达。结果繁殖成功的子代小鼠有3种基因型:野生型、杂合子及纯合子;4、10周龄雌性纯合子小鼠体重明显重于同龄的野生型小鼠(P0.05),6、10周龄雄性纯合子小鼠体重明显重于同龄的野生型小鼠(P0.05);6周龄雌性纯合子小鼠结直肠长度明显长于同周龄的野生型小鼠(P0.05),但结直肠的形态结构无显著改变;纯合子小鼠血清中CXCL4的表达量明显低于WT小鼠(P0.05)。结论成功获得了CXCL4基因敲除纯合子小鼠,为深入研究CXCL4的生物学功能奠定了基础。     

细胞焦亡与动脉粥样硬化相关性的研究进展

细胞焦亡是一种促炎形式的细胞死亡方式,且依赖于半胱天冬酶-1(cysteinyl aspartate specific proteinase-1,caspase-1)的酶活性,在形态、机制和病理生理上均不同于细胞凋亡和坏死等其他细胞死亡方式,可能参与动脉粥样硬化,并在动脉粥样硬化病变中起重要作用。细胞焦亡包括依赖caspase-1的经典焦亡通路和非caspase-1依赖的非经典焦亡通路,其具有双向作用,中度细胞焦亡有助于细胞稳态,并可能有效防止细胞过度增殖,保护宿主;另一方面,高水平细胞焦亡可能导致炎症,不利于体内平衡的维持。本文主要对细胞焦亡产生机制及内皮细胞焦亡、巨噬细胞焦亡和平滑肌细胞焦亡与动脉粥样硬化相关性的最新研究进展作一综述。     

Natural Killer T Cells Are Involved in Atherosclerotic Plaque Instability in Apolipoprotein-E Knockout Mice

The infiltration and activation of macrophages as well as lymphocytes within atherosclerotic lesion contribute to the pathogenesis of plaque rupture. We have demonstrated that invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that recognize glycolipid antigens, play a crucial role in atherogenesis. However, it remained unclear whether iNKT cells are also involved in plaque instability. Apolipoprotein E (apoE) knockout mice were fed a standard diet (SD) or a high-fat diet (HFD) for 8 weeks. Moreover, the SD- and the HFD-fed mice were divided into two groups according to the intraperitoneal injection of α-galactosylceramide (αGC) that specifically activates iNKT cells or phosphate-buffered saline alone (PBS). ApoE/Jα18 double knockout mice, which lack iNKT cells, were also fed an SD or HFD. Plaque instability was assessed at the brachiocephalic artery by the histological analysis. In the HFD group, αGC significantly enhanced iNKT cell infiltration and exacerbated atherosclerotic plaque instability, whereas the depletion of iNKT cells attenuated plaque instability compared to PBS-treated mice. Real-time PCR analyses in the aortic tissues showed that αGC administration significantly increased expressional levels of inflammatory genes such as IFN-γ and MMP-2, while the depletion of iNKT cells attenuated these expression levels compared to those in the PBS-treated mice. Our findings suggested that iNKT cells are involved in the exacerbation of plaque instability via the activation of inflammatory cells and upregulation of MMP-2 in the vascular tissues.     

Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique opportunities for the early detection and treatment of atherosclerotic disease.     

Diminazene Aceturate Stabilizes Atherosclerotic Plaque and Attenuates Hepatic Steatosis in apoE-Knockout Mice by Influencing Macrophages Polarization and Taurine Biosynthesis

Atherosclerosis and nonalcoholic fatty liver disease are leading causes of morbidity and mortality in the Western countries. The renin–angiotensin system (RAS) with its two main opposing effectors, i.e., angiotensin II (Ang II) and Ang-(1–7), is widely recognized as a major regulator of cardiovascular function and body metabolic processes. Angiotensin-converting enzyme 2 (ACE2) by breaking-down Ang II forms Ang-(1–7) and thus favors Ang-(1–7) actions. Therefore, the aim of our study was to comprehensively evaluate the influence of prolonged treatment with ACE2 activator, diminazene aceturate (DIZE) on the development of atherosclerotic lesions and hepatic steatosis in apoE^−/− mice fed a high-fat diet (HFD). We have shown that DIZE stabilized atherosclerotic lesions and attenuated hepatic steatosis in apoE^−/− mice fed an HFD. Such effects were associated with decreased total macrophages content and increased α-smooth muscle actin levels in atherosclerotic plaques. Moreover, DIZE changed polarization of macrophages towards increased amount of anti-inflammatory M2 macrophages in the atherosclerotic lesions. Interestingly, the anti-steatotic action of DIZE in the liver was related to the elevated levels of HDL in the plasma, decreased levels of triglycerides, and increased biosynthesis and concentration of taurine in the liver of apoE^−/− mice. However, exact molecular mechanisms of both anti-atherosclerotic and anti-steatotic actions of DIZE require further investigations.     

Effect of Lowering Asymmetric Dimethylarginine (ADMA) on Vascular Pathology in Atherosclerotic ApoE-Deficient Mice with Reduced Renal Mass

The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1), on atherosclerosis in subtotally nephrectomized (SNX) ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n = 39) and C57Bl/6J wild-type littermates (WT, n = 27) with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction) ApoE-competent DDAH1 transgenic and wild-type littermates (n = 11) served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD) in this mouse model.     

Pathophysiology of Atherosclerotic Plaque Development-Contemporary Experience and New Directions in Research

Atherosclerotic plaque is the pathophysiological basis of important and life-threatening diseases such as myocardial infarction. Although key aspects of the process of atherosclerotic plaque development and progression such as local inflammation, LDL oxidation, macrophage activation, and necrotic core formation have already been discovered, many molecular mechanisms affecting this process are still to be revealed. This minireview aims to describe the current directions in research on atherogenesis and to summarize selected studies published in recent years—in particular, studies on novel cellular pathways, epigenetic regulations, the influence of hemodynamic parameters, as well as tissue and microorganism (microbiome) influence on atherosclerotic plaque development. Finally, some new and interesting ideas are proposed (immune cellular heterogeneity, non-coding RNAs, and immunometabolism) which will hopefully bring new discoveries in this area of investigation.     

Identification of Oxidized Phosphatidylinositols Present in OxLDL and Human Atherosclerotic Plaque

Oxidized low-density lipoprotein (OxLDL) plays an important role in initiation and progression of atherosclerosis. Proatherogenic effects of OxLDL have been attributed to bioactive phospholipids generated during LDL oxidation. It is unknown what effect oxidation has on the phosphatidylinositol (PtdIns) molecules in LDL, even though PtdIns is 6% of the total LDL phospholipid pool. We sought to identify and quantitate oxidized phosphatidylinositol (OxPtdIns) species in OxLDL and human atherosclerotic plaque. Bovine liver PtdIns was subjected to non-enzymatic and lipoxygenase-catalyzed oxidation. Reversed-phase liquid chromatography with negative ESI–MS identified and confirmed compounds by fragmentation pattern analysis from which an OxPtdIns library was generated. Twenty-three OxPtdIns molecules were identified in copper-oxidized human LDL at 0, 6, 12, 24, 30, and 48 h, and in human atherosclerotic plaque. In OxLDL, OxPtdIns species containing aldehydes and carboxylates comprised 17.3 ± 0.1 and 0.9 ± 0.2%, respectively, of total OxPtdIns in OxLDL at 48 h. Hydroperoxides and isoprostanes at 24 h (68.5 ± 0.2 and 22.8 ± 0.2%) were significantly greater than 12 h (P < 0.01) without additional changes thereafter. Hydroxides decreased with increased oxidation achieving a minimum at 24 h (5.2 ± 0.3%). Human atherosclerotic plaques contained OxPtdIns species including aldehydes, carboxylates, hydroxides, hydroperoxides and isoprostanes, comprising 18.6 ± 4.7, 1.5 ± 0.7, 16.5 ± 7.4, 33.3 ± 1.1 and 30.2 ± 3.3% of total OxPtdIns compounds. This is the first identification of OxPtdIns molecules in human OxLDL and atherosclerotic plaque. With these novel molecules identified we can now investigate their potential role in atherosclerosis.     

BIRC6 Is Associated with Vulnerability of Carotid Atherosclerotic Plaque

Carotid atherosclerotic plaque rupture can lead to cerebrovascular accident (CVA). By comparing RNA-Seq data from vascular smooth muscle cells (VSMC) extracted from carotid atheroma surgically excised from a group of asymptomatic and symptomatic subjects, we identified more than 700 genomic variants associated with symptomatology (p < 0.05). From these, twelve single nucleotide polymorphisms (SNPs) were selected for further validation. Comparing genotypes of a hospital-based cohort of asymptomatic with symptomatic patients, an exonic SNP in the BIRC6 (BRUCE/Apollon) gene, rs35286811, emerged as significantly associated with CVA symptomatology (p = 0.002; OR = 2.24). Moreover, BIRC6 mRNA levels were significantly higher in symptomatic than asymptomatic subjects upon measurement by qPCR in excised carotid atherosclerotic tissue (p < 0.0001), and significantly higher in carriers of the rs35286811 risk allele (p < 0.0001). rs35286811 is a proxy of a GWAS SNP reported to be associated with red cell distribution width (RDW); RDW was increased in symptomatic patients (p < 0.03), but was not influenced by the rs35286811 genotype in our cohort. BIRC6 is a negative regulator of both apoptosis and autophagy. This work introduces BIRC6 as a novel genetic risk factor for stroke, and identifies autophagy as a genetically regulated mechanism of carotid plaque vulnerability.     

Different Approaches in Therapy Aiming to Stabilize an Unstable Atherosclerotic Plaque

Atherosclerotic plaque vulnerability is a vital clinical problem as vulnerable plaques tend to rupture, which results in atherosclerosis complications—myocardial infarctions and subsequent cardiovascular deaths. Therefore, methods aiming to stabilize such plaques are in great demand. In this brief review, the idea of atherosclerotic plaque stabilization and five main approaches—towards the regulation of metabolism, macrophages and cellular death, inflammation, reactive oxygen species, and extracellular matrix remodeling have been presented. Moreover, apart from classical approaches (targeted at the general mechanisms of plaque destabilization), there are also alternative approaches targeted either at certain plaques which have just become vulnerable or targeted at the minimization of the consequences of atherosclerotic plaque erosion or rupture. These alternative approaches have also been briefly mentioned in this review.     

The Impact of Cytokines in Coronary Atherosclerotic Plaque: Current Therapeutic Approaches

Coronary atherosclerosis is a chronic pathological process that involves inflammation together with endothelial dysfunction and lipoprotein dysregulation. Experimental studies during the past decades have established the role of inflammatory cytokines in coronary artery disease, namely interleukins (ILs), tumor necrosis factor (TNF)-α, interferon-γ, and chemokines. Moreover, their value as biomarkers in disease development and progression further enhance the validity of this interaction. Recently, cytokine-targeted treatment approaches have emerged as potential tools in the management of atherosclerotic disease. IL-1β, based on the results of the CANTOS trial, remains the most validated option in reducing the residual cardiovascular risk. Along the same line, colchicine was also proven efficacious in preventing major adverse cardiovascular events in large clinical trials of patients with acute and chronic coronary syndrome. Other commercially available agents targeting IL-6 (tocilizumab), TNF-α (etanercept, adalimumab, infliximab), or IL-1 receptor antagonist (anakinra) have mostly been assessed in the setting of other inflammatory diseases and further testing in atherosclerosis is required. In the future, potential targeting of the NLRP3 inflammasome, anti-inflammatory IL-10, or atherogenic chemokines could represent appealing options, provided that patient safety is proven to be of no concern.