全反式维甲酸及依托泊苷对急性早幼粒细胞白血病细胞磷脂酰丝氨酸暴露及促凝血活性的影响

目的：探讨磷脂酰丝氨酸（PS）暴露在急性早幼粒细胞白血病（APL）细胞促凝血活性中的作用及不同药物对其产生的影响。方法：实验共分为4组：新采集APL细胞组、APL细胞单纯培养组、APL细胞全反式维甲酸（ATRA）处理组及APL细胞依托泊苷（VP16）处理组。提取10名初发APL患者的骨髓APL细胞进行实验,提取10名健康成人外周血单个核细胞作为凝血实验的正常对照。分别用1μmol·L-1ATRA和1μmol·L-1VP16处理APL细胞24 h,利用共聚焦显微镜及流式细胞术检测各组细胞PS暴露情况。利用凝血实验检测各组细胞总的促凝活性及细胞表面磷脂的促凝血活性。利用PS特异结合蛋白乳粘素对各组细胞进行凝血抑制实验。结果：新采集的APL细胞存在一定量的PS外翻,并且与外周血单个核细胞相比,存在更高的促凝血活性（P〈0.05）,ATRA对APL细胞的PS外翻及促凝活性有抑制作用（P〈0.05）,VP16则对其有显著的促进作用（P〈0.001）。乳粘素可以拮抗APL细胞至少70%的促FXa和FIIa生成活性。结论：PS暴露在APL细胞促凝血过程中发挥着重要作用。分化治疗药物ATRA和化疗药物VP16分别通过减少和增加APL细胞表面PS的暴露来减轻和加重凝血紊乱。乳粘素通过与PS特异结合可以有效地阻断暴露的PS的促凝活性,是一种潜在的治疗APL凝血紊乱的抗凝剂。     

组织因子阳性的细胞和微粒在胃癌高凝状态中的作用

目的:探讨胃癌患者血浆中组织因子阳性的血小板、白细胞和微粒的数量及其促凝活性。方法:将45例胃癌患者根据TNM分期分为Ⅰ、Ⅱ、Ⅲ、Ⅳ期,同时选取30例健康人作为对照组。采用流式细胞术检测组织因子阳性的细胞和微粒数。凝血酶生成实验检测细胞和微粒的凝血活性。结果:胃癌Ⅲ/Ⅳ期患者血浆中组织因子阳性的血小板、中性粒细胞、单核细胞和微粒的数量明显高于胃癌Ⅰ/Ⅱ期和健康对照组。胃癌Ⅲ/Ⅳ期患者血小板、白细胞和微粒的促凝活性与其他组相比显著升高,与增加凝血酶的生成速度和生成总量有关。用抗组织因子抗体抑制TF后,细胞和微粒的凝血活性明显下降。然而,使用抗膜连蛋白V抑制PS后,细胞和微粒的凝血活性虽然有下降趋势,但是并不明显。此外,根治性手术治疗可以降低组织因子阳性的血小板、中性粒细胞、单核细胞和微粒的数量。结论:组织阳性的血小板、中性粒细胞、单核细胞和微粒是胃癌Ⅲ/Ⅳ患者高凝状态的原因之一,通过抑制TF和凝血酶的生成可能降低胃癌患者的血栓发生率。     

可溶性组织因子突变体的基因构建、表达和性质

血浆中组织因子 (TF)的过量表达与许多病理过程密切相关。TF抑制物有可能防治这些疾病。设计了两种可溶性组织因子 (sTF)的突变体 (MCsTF和MFsTF) ,突变了协同催化的功能域 ,保留与因子VII/VIIa结合的功能域 ,使突变体竞争性抑制野生型TF的功能。用PCR的方法 ,对可溶性组织因子cDNA基因进行了点突变 ,并实现了在大肠杆菌中高效表达。rsTF、rMCsTF和rMFsTF的促凝活性研究表明 ,rMFsTF的激活X因子活性和促凝血作用相当于rsTF的 10 % ,而rMCsTF几乎完全失去了激活X因子活性和促凝血作用。rMCsTF和rMFsTF与VII/VIIa因子形成复合物对激活X因子的催化特异常数 (kcat/Km)分别是FVII/VIIa·rsTF的 2 .0 %和 3.7% ,也说明突变体与VII/VIIa形成的复合物对激活X因子催化活性显著降低。rMCsTF和rMFsTF对rsTF活性抑制动力学研究及体外活性研究表明 ,两种突变体均有抑制rsTF活性和抑制兔脑粉的促凝活性作用 ,抑制作用呈量效关系     

骨髓单个核细胞抗体及外周血B淋巴细胞与IRP的相关性研究

采用流式细胞术双标法检测拟诊免疫相关性全血细胞减少症患者(A组)、非免疫相关性恶性血液病患者(B组)及正常人(正常对照组)的骨髓单个核细胞结合的自身抗体,同时检测B组、确诊免疫相关性全血细胞减少症(C组)及正常对照组外周血B淋巴细胞及CD5+B淋巴细胞比率;A组中16例骨髓造血细胞自身抗体阳性,阳性率88.88%;B组1例骨髓造血细胞自身抗体阳性,阳性率9.09%。C组外周血B淋巴细胞、CD5+B淋巴细胞比率显著高于B组及正常对照组(P均<0.05),而正常对照组外周血B淋巴细胞、CD5+B淋巴细胞显著高于B组(P均<0.05);IRP患者骨髓单个核细胞自身抗体表达显著增高,B淋巴细胞总数及CD5+B淋巴细胞数量显著增高可能是IRP发病的重要因素之一;利用流式细胞术检测骨髓造血细胞自身抗体及B淋巴细胞数可以为IRP提供科学可靠的依据,优于骨髓Coomb’s实验。     

微粒在动脉粥样硬化形成及凝血异常中的作用

微粒是血管内皮细胞、组织细胞或血细胞激活或凋亡时形成的亚微型囊泡。动脉粥样硬化时血浆及粥样斑块中富含多种细胞来源的微粒,不仅促进斑块的发生发展并且在动脉粥样硬化凝血异常中起重要作用,可增进血管内皮细胞和白细胞间的相互作用,使单核细胞粘附于内皮细胞,从而迁移到斑块内,吞噬清除内膜下沉积的脂质。巨噬细胞吞噬脂质后凋亡形成大量微粒,抑制内皮细胞合成释放一氧化氮,加重内皮细胞损伤,促进斑块扩大。微粒表面富含的磷脂酰丝氨酸和组织因子是微粒促凝活性的主要来源,病灶处及循环中存在的大量微粒促进了动脉粥样硬化时凝血异常的发生。本文将就微粒在动脉粥样硬化形成及凝血异常中的作用做一综述。     

石墨烯量子点对大鼠造血系统的影响

目的:研究石墨烯量子点(GQDs)对大鼠造血系统的影响。方法:30只SD雄性大鼠随机分为3组(n=10):对照组、高、低剂量GQDs实验组(10 mg/kg·d,5 mg/kg·d),对照组尾静脉注射等容积生理盐水,实验组尾静脉注射GQDs,连续28 d。麻醉处死,心脏取血,检测血常规及肝肾功能,获取骨髓单个核细胞(BMCs),流式细胞仪检测细胞周期及凋亡情况。另取3只健康雄性SD大鼠体外培养大鼠四肢骨髓单个核细胞,GQDs分别作用24 h,48 h,72 h后,CCK-8检测细胞增殖情况,ELISA检测细胞上清液中粒-巨细胞刺激集落因子(GM-CSF)含量。结果:GQDs在10 mg/kg·d剂量范围内,实验组大鼠红细胞数和血红蛋白浓度显著增高(P0.05);白细胞和淋巴细胞有增高的趋势;骨髓单个核细胞周期DNA合成前期(G1期)缩短(P0.01),DNA合成期(S期)显著延长(P0.01),细胞凋亡无明显影响;甘油三酯和高密度蛋白浓度显著降低(P0.01)。GQDs作用72 h大鼠骨髓单个核细胞明显增殖(P0.05),细胞上清液中GM-CSF含量显著增加(P0.01)。结论:一定浓度的GQDs可促进大鼠造血功能。     

凋亡诱导因子在姜黄素诱导的大鼠肺成纤维细胞凋亡中的作用

目的：研究姜黄素对肺纤维化大鼠肺成纤维细胞增殖、凋亡的影响,探讨凋亡诱导因子（AIF）在肺成纤维细胞凋亡中的作用。方法：将体外培养的肺纤维化大鼠成纤维细胞,分别于不同浓度的姜黄素（5、10、20、40μM）和caspase-3抑制剂Z-DEVD-fmk（20μM）孵育,观测细胞生长状态变化。MTT检测成纤维细胞增殖抑制率;流式细胞仪检测细胞凋亡率;Western-Blot测定凋亡诱导因子（AIF）蛋白表达及核转位结果：流式细胞术检测细胞凋亡,5～40μM姜黄素处理12 h,其凋亡率呈浓度依赖,对照组相比,差异显著;而抑制caspase-3并不能完全阻止细胞凋亡。Western-Blot结果显示,姜黄素处理组出现凋亡诱导因子（AIF）蛋白表达与核转位,抑制caspase-3活性后未检测出AIF表达结论：姜黄素可抑制肺成纤维细胞增殖,其诱导大鼠肺成纤维细胞凋亡,可能与线粒体释放AIF有关。     

γ-生育三烯酚联合亚砷酸对急性早幼粒细胞NB4生长的抑制作用及机制

目的:研究γ-生育三烯酚联合亚砷酸对急性早幼粒细胞NB4生长的抑制作用及可能的分子机制。方法:采用CCK-8、细胞周期实验检测细胞增殖、利用激光共聚焦显微镜、Annexin V/PI染色、Caspase活性检测、Western Blot等方法测定细胞凋亡。采用1μmol/L ATO及不同浓度(0、15、30、45μmol/L)的γ-生育三烯酚处理NB4细胞24、48和72小时,通过CCK-8检测细胞的增殖情况,流式细胞术、激光共聚焦显微镜检测细胞周期和凋亡情况,检测Caspase3,8,9的活性,Western Blot检测细胞中c-caspase-3、Bcl-2和survivin的蛋白表达。结果:γ-生育三烯酚联合亚砷酸显著抑制NB4细胞增殖(P0.01),且随着作用时间延长和γ-生育三烯酚浓度的增加,其增殖抑制作用增强;细胞周期阻滞在S期,S期的比例由38.21%±2.99上升到50.31%±5.03;γ-生育三烯酚联合亚砷酸诱导NB4细胞凋亡,1μmol/L ATO联合15、30μmol/L的γ-生育三烯酚处理48h后,细胞活率分别为82.27%±3.16、66.97%±3.17、12.63%±2.66;1μmol/L ATO联合30μmol/L的γ-生育三烯酚处理后,NB4细胞caspase-3,-8,-9的活性均较ATO单独用药组显著增高,c-caspase-3表达增高而Bcl-2和survivin蛋白的表达无明显变化。结论:生育三烯酚联合亚砷酸对急性早幼粒细胞NB4的生长具有抑制作用,此作用可能与抑制增殖并诱导凋亡相关,其作用靶点可能与促进Cas-pase诱导的凋亡有关。     

凋亡诱导因子在姜黄素诱导的大鼠肺成纤维细胞凋亡中的作用

目的:研究姜黄素对肺纤维化大鼠肺成纤维细胞增殖、凋亡的影响,探讨凋亡诱导因子(AIF)在肺成纤维细胞凋亡中的作用.方法:将体外培养的肺纤维化大鼠成纤维细胞,分别于不同浓度的姜黄素(5、10、20、40μM)和caspase-3抑制剂Z-DEVD-fmk(20μM)孵育,观测细胞生长状态变化.MTT检测成纤维细胞增殖抑制率;流式细胞仪检测细胞凋亡率;Western-Blot测定凋亡诱导因子(AIF)蛋白表达及核转位结果:流式细胞术检测细胞凋亡,5～40μM姜黄素处理12 h,其凋亡率呈浓度依赖,对照组相比,差异显著;而抑制caspase-3并不能完全阻止细胞凋亡.Western-Blot结果显示,姜黄素处理组出现凋亡诱导因子(AIF)蛋白表达与核转位,抑制caspase-3活性后未检测出AIF表达结论:姜黄素可抑制肺成纤维细胞增殖,其诱导大鼠肺成纤维细胞凋亡,可能与线粒体释放AIF有关.     

凝血因子VII基因表达载体的构建及其在BHK细胞中的表达

凝血因子Ⅶ是凝血块形成的起始关键分子之一,它对外源性凝血途径的启动具有重要的作用。为表达具有促凝活性的重组人凝血因子Ⅶ,通过PCR的方法从质粒pUC-FⅦ中扩增人凝血因子ⅦcDNA,并将其定向克隆入真核表达载体pIRESneo中,构建重组表达载体pIRES-FⅦ,测序正确后用脂质体介导的方法转染BHK-21细胞,经G418加压筛选、细胞有限稀释等方法获得克隆细胞株,收集无皿清培养上清,进行SDS-PAGE、Western blot和活性鉴定。结果成功构建了重组表达载体pIRES-FⅦ,实现了其在BHK-21细胞中的表达,且表达产物具有促凝活性。重组人凝血因子Ⅶ在哺乳动物细胞中的成功表达,为整体止血剂的研究奠定了基础。     

Flow cytometric analysis of tissue factor (TF) expression on stimulated monocytes--comparison to procoagulant activity of mononuclear blood cells

Whereas tissue factor (TF), a 47 kDa transmembrane glycoprotein, is constitutively present in certain tissues such as epithelial tissue, brain, and placenta, it is normally not expressed by cells within the vasculature. However, inflammatory mediators including bacterial lipopolysaccharide (LPS) can stimulate the expression of cell surface procoagulant activity (PCA) on monocytes. In our present study the kinetics (over 24 h) of molecular TF expression on LPS-stimulated monocytes analyzed by flow cytometry corresponds closely to functional PCA of human mononuclear blood cells (MBC). Both PCA and TF expression on monocytes were rapid events reaching their maximum after about 6 h of stimulation. At this time approximately 70-80% of monocytes had also achieved maximum anti-TF MAb receptor density. For certain analytical applications, monitoring of molecular TF expression on monocytes by flow cytometry using anti-TF MAb is favorable because there is no influence by PCA inhibitors.     

Functional tissue factor is entirely cell surface expressed on lipopolysaccharide-stimulated human blood monocytes and a constitutively tissue factor-producing neoplastic cell line

Tissue factor (TF) is an integral membrane glycoprotein which, as the receptor and essential cofactor for coagulation factors VII and VIIa (FVII and FVIIa, respectively), is the primary cellular activator of the coagulation protease cascade. Previous studies on the procoagulant activity of a variety of cell types (either lysed or in the intact state) have variously been interpreted as showing that TF is either stored intracellularly or is present in a cryptic form in the surface membrane. Using mAbs to TF, we have directly investigated the subcellular localization and functional activity of TF in lipopolysaccharide-stimulated blood monocytes and J82 bladder carcinoma cells. Blocking of surface TF of viable cells with inhibitory anti-TF mAbs abolished greater than 90% of TF activity of the intact cells as well as of lysed cells. Furthermore, quantitative analysis of the binding of FVII and anti-TF mAb to J82 cells demonstrated that all surface-expressed TF molecules were capable of binding the ligand, FVII. By immunoelectron microscopy, TF was present only in the surface membrane of monocytes and J82 cells, although the latter also contained apparently inactive TF antigen in multivesicular bodies. On the intact cell surface the catalytic activity of the TF-FVIIa complex was investigated and found to be markedly less relative to cell lysates. Membrane alterations that affect the cofactor activity of TF may be a means of regulating the extent of initiation of the coagulation protease cascade in various cellular settings.     

A novel C5a receptor-tissue factor cross-talk in neutrophils links innate immunity to coagulation pathways

Neutrophils and complement are key sentinels of innate immunity and mediators of acute inflammation. Recent studies have suggested that inflammatory processes modulate thrombogenic pathways. To date, the potential cross-talk between innate immunity and thrombosis and the precise molecular pathway by which complement and neutrophils trigger the coagulation process have remained elusive. In this study, we demonstrate that antiphospholipid Ab-induced complement activation and downstream signaling via C5a receptors in neutrophils leads to the induction of tissue factor (TF), a key initiating component of the blood coagulation cascade. TF expression by neutrophils was associated with an enhanced procoagulant activity, as verified by a modified prothrombin time assay inhibited by anti-TF mAb. Inhibition studies using the complement inhibitor compstatin revealed that complement activation is triggered by antiphospholipid syndrome (APS) IgG and leads to the induction of a TF-dependent coagulant activity. Blockade studies using a selective C5a receptor antagonist and stimulation of neutrophils with recombinant human C5a demonstrated that C5a, and its receptor C5aR, mediate the expression of TF in neutrophils and thereby significantly enhance the procoagulant activity of neutrophils exposed to APS serum. These results identify a novel cross-talk between the complement and coagulation cascades that can potentially be exploited therapeutically in the treatment of APS and other complement-associated thrombotic diseases.     

Atherothrombosis: role of tissue factor; link between diabetes, obesity and inflammation

Atherothrombotic vascular disease is a complex disorder in which inflammation and coagulation play a pivotal role. Rupture of high-risk, vulnerable plaques with the subsequent tissue factor (TF) exposure is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. Tissue factor (TF), the key initiator of coagulation is an important modulator of inflammation. TF is widely expressed in atherosclerotic plaques and found in macrophages, smooth muscle cells, extracellular matrix and acellular lipid-rich core. TF expression can be induced by various stimulants such as C-reactive protein, oxLDL, hyperglycemia and adipocytokines. The blood-born TF encrypted on the circulating microparticles derived from vascular cells is a marker of vascular injury and a source of procoagulant activity. Another form of TF, called alternatively spliced has been recently identified in human and murine. It is soluble, circulates in plasma and initiates coagulation and thrombus propagation. Evidence indicates that elevated levels of blood-borne or circulating TF has been associated with metabolic syndrome, type 2 diabetes and cardiovascular risk factors and is a candidate biomarker for future cardiovascular events. Therapeutic strategies have been developed to specifically interfere with TF activity in the treatment of cardiovascular disease.     

Characterisation of disseminated tumor cells in the bone marrow of breast cancer patients by the Thomsen–Friedenreich tumor antigen

The detection of disseminated tumor cells in the bone marrow (DTC-BM) of breast cancer patients has proved prognostic significance in all stages of the disease. Further characterisation of those cells could help to improve the biological understanding of metastases, develop targeted therapies and define surface markers for enrichment techniques. The Thomsen–Friedenreich (TF) antigen has been shown to be a tumor specific antigen in breast cancer. The aim of this study was to investigate the expression of TF on DTC-BM in 25 patients. Bone marrow samples were first double-stained by a Cy3 conjugated cytokeratin (CK) antibody (ab) A45 B/B3 (IgG) and anti-TF ab Nemod 2 (IgM), followed by Cy2 conjugated goat anti-mouse IgM ab. For further characterisation samples were also double-stained with anti-TF ab Nemod 2 (IgM), followed by Cy2 conjugated goat anti-mouse IgM ab, and anti MUC1 ab A76-A/C7 IgG, followed by Cy3 conjugated goat anti-mouse IgG. CK positive DTC-BM showed co-expression of TF antigen in 22/23 patients (96%) and 61 of 62 detected cells (98%). Mononuclear BM cells without CK expression were also negative for TF. All of the TF positive cells showed strong MUC1 expression. This is the first study showing co-expression of CK and TF as markers of DTC-BM. Double staining experiments of TF and MUC1 expression showed that MUC1 is the carrier protein of TF in these cells. As TF is a specific marker of DTC-BM, it could be used as a target for antibody based therapy and immunomagnetic enrichment techniques for the isolation of DTC-BM.     

Properties of proteins in cancer procoagulant preparations that are detected by anti-tissue factor antibodies

Cancer procoagulant (CP) and tissue factor (TF; only in complex with Factor VIIa (FVIIa)) can activate FX to FXa. Controversy still exists whether or not CP is an entity different from TF, or whether CP activity is due to contamination of CP preparations with TF/FVIIa complex. We therefore looked for proteins in CP preparations that were detected by anti-TF antibodies and then sequenced these proteins. One- and two-dimensional gels of CP and TF were used to identify proteins immunoreactive to monoclonal anti-CP and anti-TF antibodies (Mabs). Those proteins in the CP preparation recognized by anti-TF antibodies were sequenced. Angiotensinogen precursor, alpha-1-antitrypsin precursor, and vitamin D-binding protein were identified along with one so far unidentified sequence; however, no TF-sequences were identified. Also, no proteins with the correct molecular weight for TF were identified using anti-TF antibodies. It seems possible that CP preparations contain proteins that have some epitopes similar to the epitopes recognized in TF by anti-TF Mab. However, these proteins do neither have the molecular weight nor the amino acid sequence of TF.