Phagocytosis of IgA Immune Complexes by Human U937 Cells

Human promonocytic cell line U937 can express both IgAFc receptors ( FcαRⅠ, CD89 ) and IgG Fc receptors(FcαγⅠ, FcγRⅡ and FcγRⅢ)[1]. These receptors canmediate a variety of cell reactions including phagocytosis ofimmune complexes ( ICs ), degranulation, respiratorybursts, release of cytokines and enhancement of antibody dependent cell mediated cytotoxicity (ADCC) [2]. AfterIgA and IgG form ICs with their corresponding antigens,the ICs are bound by FcR on phagocyt…     

Apoptin基因/壳聚糖纳米粒的制备及其对U937细胞凋亡的诱导作用

目的以羧甲基壳聚糖为基质材料,制备apoptin基因缓释微球,探讨其对U937细胞凋亡的作用。方法采用复凝聚法制备apoptin/壳聚糖微球,分别用光镜观察微球形态、内切酶研究其稳定性、DNA电泳阻滞分析apoptin/壳聚糖最佳比例、PCR测定apoptin基因作为复制摸板能力、用MTT法检测其抗肿瘤活性。结果壳聚糖与apoptin基因可形成稳定的微球,其直径在200～300之间,成球性较好,apoptin/壳聚糖微球P/N最佳质量比为5.5:1。微球能够有效防止DNA酶的降解作用,apoptin/微球载体中的基因仍具有DNA复制摸板功能,并能有效地转染U937细胞,转染48h可诱导U937细胞发生凋亡,从而抑制瘤细胞生长。结论apoptin基因与羧甲基壳聚糖可形成稳定的缓释微球,并能有效地转染肿瘤细胞,诱导肿瘤细胞发生凋亡。     

可注射原位给药体系在蛋白类药物给药中的应用

可注射进入病灶部位并能原位给药的体系具有操作简单、局部给药、延长药物释放时间、减少用药剂量等诸多优点.近年来,各国研究者竞相研究可注射原位给药体系,并将其作为亲水性大分子药物尤其是蛋白类药物的药物载体.本文主要介绍了热塑性糊状体、原位交联聚合物体系、原位聚合物沉淀和热诱导凝胶体系四种缓释药物体系,着重讨论了将其作为蛋白类药物载体的优缺点.     

Designing Nanoparticle-based Drug Delivery Systems for Precision Medicine

Traditional drugs are facing bottlenecks of lower solubility, absorption, and especially the inefficient organs or cells targeting during the precision medicine era. It is urgently needed to discover and establish new methods or strategies to modify old drugs or create new ones against the above defects. With the support of nanotechnology, the solubility, absorption and targeting of traditional drugs were greatly improved by modifying and fabricating with various types of nanoparticles to some extent, though many shortages remain. In this mini-review we will focus on advances in several most commonly used nanoparticles, from their nature and design, to drug delivery system and clinical application, that they overcome heterogeneous barriers in precision medicine, thereby ultimately improve patient outcome overall.     

靶向给药系统的体内药物动力学分析

建立靶向给药系统的体内药物动力学模型.以房室模型理论为依据,结合质量守恒原理,建立了数学模型,推导出了靶器官的药时函数表达式,并用实验数据验证了其准确性.根据所得靶器官的药时函数表达式,用统计矩方法分析了靶向给药系统的靶器官药物动力学规律,给出了靶器官的药物动力学参数.结果表明:靶器官中的药时函数表达式与实验数据能很好地拟合.我们所建立的药时函数表达式能很好地刻画靶向制剂体内药物动力学规律.     

超声可控释药体系研究进展

超声可控释药体系是一种新兴的靶向给药及基因转运方法。以超声敏感材料作为药物或基因转送的载体,当超声辐照于靶组织或靶器官时, 靶体内载体可定向释放出包裹或附着的基因或药物, 实现对负载药物的定时定量定点释放和提高药物输送效率或基因转染率的目的。文中对超声可控释药体系的作用机制、超声敏感载体材料及生物医学应用等方面进行综述,最后对该领域目前存在的问题和今后的发展方向提出了一些看法。     

槲皮素对U937细胞系抑制增殖和诱导凋亡作用的研究

目的 探讨黄酮类化合物槲皮素（Que）对人类单核细胞白血病U937细胞系的抑制增殖和诱导凋亡的作用。方法 应用MTT法检测不同浓度槲皮素对U937细胞的增殖抑制作用；AO／PI荧光染色后倒置荧光显微镜下观察细胞形态学变化；琼脂糖凝胶电泳测定细胞DNA的片段化；应用流式细胞仪检测细胞凋亡率及细胞周期分布。结果槲皮素能明显抑制U937细胞增殖，并存在剂量-效应关系和时间-效应关系；诱导U937细胞出现凋亡所具有的形态学和生化特征；随着槲皮素浓度升高，凋亡细胞和坏死细胞比例增加；将细胞特异性地阻滞在S期，出现凋亡峰。结论 槲皮素能抑制U937细胞增殖，诱导细胞凋亡，并具有细胞周期特异性。     

槲皮素对U937细胞系抑制增殖和诱导凋亡作用的研究

目的探讨黄酮类化合物槲皮素(Que)对人类单核细胞白血病U937细胞系的抑制增殖和诱导凋亡的作用.方法应用MTT法检测不同浓度槲皮素对U937细胞的增殖抑制作用;AO/PI荧光染色后倒置荧光显微镜下观察细胞形态学变化;琼脂糖凝胶电泳测定细胞DNA的片段化;应用流式细胞仪检测细胞凋亡率及细胞周期分布.结果槲皮素能明显抑制U937细胞增殖,并存在剂量-效应关系和时间-效应关系;诱导U937细胞出现凋亡所具有的形态学和生化特征;随着槲皮素浓度升高,凋亡细胞和坏死细胞比例增加;将细胞特异性地阻滞在S期,出现凋亡峰.结论槲皮素能抑制U937细胞增殖,诱导细胞凋亡,并具有细胞周期特异性.     

人血单核细胞和U937细胞产生IFN-α的比较

一般认为人体单核-巨噬细胞(Mo-Mφ)系在体外诱生IFN-α较为困难,本文试图找到适合的培养条件,使Mo-M(?)系能在体外诱生IFN-α.结果显示:经M-CSF长期预处理和IFN-γ的短期预处理或单用IFN-γ短期预处理后,NDV刺激均能使人外周血Mo-M(?)产生较高水平的IFN-α;U937细胞只能产生低水平的IFN-α.     

Streptococcal Pyrogenic Exotoxin B Induces Apoptosis and Reduces Phagocytic Activity in U937 Cells

Treatment of U937 human monocyte-like cells with Streptococcus pyogenes led to an induction of apoptosis in these cells. A comparison between the wild-type strain and its isogenic protease-negative mutant indicated that the production of streptococcal pyrogenic exotoxin B (SPE B), a cysteine protease, caused a greater extent of apoptosis in U937 cells. Further study using purified SPE B showed that this protease alone could induce U937 cells to undergo apoptosis, which was characterized by morphologic changes, DNA fragmentation laddering on the gel, and an increase in the percentages of hypodiploid cells. The protease activity of SPE B was required for apoptosis to proceed, since treatment with cysteine protease inhibitor E64 or heat inactivation abrogated this death-inducing effect. The SPE B-induced apoptosis pathway was interleukin-1β converting enzyme (ICE) family protease dependent. Further experiments showed that the phagocytic activity of U937 cells was reduced by SPE B. Treatment with E64 and heat inactivation both abrogated this phagocytosis-inhibitory effect. Taken together, the present data show that SPE B not only possesses the ability to induce apoptosis in monocytic cells but also helps bacteria to resist phagocytosis by host cells.     

Carvedilol Modulates In-Vitro Granulocyte-Macrophage Colony-Stimulating Factor-Induced Interleukin-10 Production in U937 Cells and Human Monocytes

Both granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-10 (IL-10) are important mediators regulating inflammatory responses. Inflammatory processes have an important role in atherogenesis. In this paper, the effects of carvedilol on GM-CSF-induced IL-10 production were examined on human monocytic cell line, U937, and purified human monocytes. First, we showed that one-time carvedilol pretreatment at concentrations 0.3-10 μM dose-dependently inhibited GM-CSF-induced IL-10 production in U937 cells. In addition, we found carvedilol to be non-cytotoxic at concentrations equal to or less than 10 μM. However, at concentrations higher than 10 μM, carvedilol induced programmed cell death in U937 cells. The inhibition of GM-CSF-induced IL-10 production by carvedilol was also observed at the expression of mRNA. Furthermore, the inhibition of IL-10 production was demonstrated in GM-CSF-activated purified human peripheral blood monocytes. Finally, long-term carvedilol pretreatment of U937 cells up to 2 months at concentrations of 1.0 μM mildly enhanced the IL-10 production. Our observations that carvedilol modulated GM-CSF-induced IL-10 production may have some implication in understanding the broad-spectrum effects of carvedilol in regulating inflammatory reactions.     

Selective Enhancement of Leu Cam Expression by Interleukin 6 during Differentiation of Human Promonocytic U937 Cells

Interleukin 6 (IL-6) is a cytokine with multiple biological activities on various tissues and cells. We have investigated the effect of recombinant human IL-6 (rhIL-6) on growth and differentiation of U937. Recombinant human IL-6 induced a dose-dependent growth inhibition, apparent around day 4, of up to 50% by day 8 of culture. Concomitant with this, changes in cytochemical activities were observed, indicative of differentiation. A panel of U937 antigens was analysed after culture with rhIL-6. Expression of the majority of these membrane antigens was unaffected, with the exception of two classes. First, rhIL-6 had a profound effect on members of the leucocytic cell adhesion molecules (Leu-CAM) family. Expression of the alpha-chain of CR3 (complement receptor 3; CD11b) was enhanced in a dose-dependent fashion, with maximal expression around day 7. Parallel to this a simultaneous increase in beta-chain (CD18) expression was found. Furthermore, enhanced expression of CR3 was, accompanied by increased rosetting with sheep erythrocytes sensitized with C3bi. A much lower, but significant, enhancement was observed for the alpha-chain of the p150,95 antigen (CD11c). Expression of leucocyte function-associated antigen-1, (LFA-1), (CD11a/CD18) remained unchanged. Remarkably, however, expression of a ligand of LFA-1, intercellular adhesion molecule-1 (ICAM-1; CD54), was enhanced with similar kinetics as CR3 and p150,95. A specific anti-rhIL-6 antiserum completely inhibited the IL-6 effect. These observations provide further support for an important role of IL-6 in the regulation of myeloid cell development in man.     

Microneedle Transdermal Drug Delivery Systems for Allergen-Specific Immunotherapy,Skin Disease Treatment,and Vaccine Development

Transdermal drug delivery systems (TDDSs) overcome the hurdle of an intact skin barrier by penetrating the skin to allow molecules through. These systems reduce side effects associated with conventional hypodermic needles. Here, we introduce novel microneedle (MN) TDDSs that enhance drug delivery by creating micron-sized pores across the skin. Many MN TDDSs designed to deliver a diverse array of therapeutics, including allergen-specific immunotherapy, skin disease treatments, and vaccines, are under pre-clinical and clinical trials. Although epicutaneous approaches are emerging as new options for treating food allergy in many clinical trials, MN TDDSs could provide a more efficient and convenient route to deliver macromolecules. Furthermore, MN TDDSs may allow for safe vaccine delivery without permanent scars. MN TDDSs are a major emerging strategy for delivering novel vaccines and treatments for diseases, including skin diseases, allergic diseases, and so on.     

应用Fura－2／AM和Probenecid测定免疫细胞胞浆游离Ca~（2＋）浓度

人Ｂ细胞系Ｒａｊｉ和ＭΦ系Ｕ９３７细胞可将负载于胞内的Ｃａ￣（２＋）荧光示踪剂Ｆｕｒａ－２外排和房室化，质膜有机阴离子转运系统抑制剂Ｐｒｏｂｅｎｅｃｉｄ能阻断这些过程，而且对细胞Ｃａ￣（２＋）应答无不良影响。提示Ｒａｊｉ和Ｕ９３７细胞质膜上具有Ｆｕｒａ－２的转运系统；Ｐｒｏｂｅｎｅｃｉｄ可作为应用Ｆｕｒａ－２／ＡＭ研究这些细胞Ｇ２￣（２＋）应答的试剂。     

外源性ApoE3对U937细胞摄取VLDL两亚组分的影响

目的研究巨噬细胞(Mφ)分泌的载脂蛋白E(ApoE)在贫含ApoE的极低密度脂蛋白(ApoE-poor-VLDL)导致Mφ泡沫化中的作用.方法建立稳定表达ApoE3的U937细胞系,该细胞系分别与FITC标记的不同浓度的ApoE-poor-VLDL及ApoE-rich-VLDL孵育,以细胞内荧光强度/蛋白浓度为观测指标,观察外源性ApoE3的表达对U937细胞摄取VLDL两亚组分的影响.结果外源性ApoE3的表达显著促进U937细胞摄取ApoE-poor-VLDL(P＜0.05),而对ApoE-rich-VLDL的摄取无显著影响(P＞0.05).结论 Mφ分泌的ApoE可能参与到ApoE-poor-VLDL中,提高其中ApoE的含量,从而介导Mφ摄取ApoE-poor-VLDL,是ApoE-poor-VLDL导致Mφ内脂质堆积的主要原因.     

Optimal Design of Needle Array for Effective Drug Delivery

Recently, the multi-needle drug injection has been adopted to overcome the shortcomes of conventional single-needle injection, enhancing the efficiency of drug delivery. However, the effect of needle array on the efficacy of drug delivery has not been fully elucidated. In this study, the interactions of drug analogous solution injected from a pair of needles were analyzed to examine the design criteria of effective multi-needle devices for drug delivery. Temporal and spatial variations of relative contents of the solution in the tissues were compared according to the distance between two adjacent needles (DN). As the DN increases from 5 to 20 D, where D is the needle diameter, the solution from each needle encounters 3.5 times faster, and 4.22 times more solution was accumulated. At the same time, the effective spreading area was continuously increased from 54.2 to 177.8 mm² and RCS gradient decreases from 0.087 to 0.037, due to the overlapping effect of the spreading solution from neighboring needles. Finally, based on the experimental results, an optimal design criterion of needle array for effective drug delivery was proposed. The present results would be helpful in the design of multi-needle injection devices and eventually offer advantage to patients with effective drug delivery.     

微型药品输送压电泵的性能分析与试验研究

微系统(泵)给药易于控制药品释放速度,进而提高药物疗效。研制了一种微型薄膜阀压电驱动微型泵,适用于内置式或便携式药品输送系统。分析压电振子及阀片动态特性的影响因素,给出了薄膜阀片谐振频率的计算方法。分析结果表明,阀和压电振子的耦合作用决定了压电泵的输出特性,对于确定的压电振子,通过阀片设计可提高压电泵的最佳工作频率和输出能力。制作了阀片尺寸不同的两个微型压电泵,进行了对比试验。小阀片微型压电泵输出的能力及最佳工作频率较高,且有两个最佳工作频率段(800Hz和3000Hz),输出流量和压力分别为3.5ml/min和27KPa;大阀片压电泵的输出能力和最佳工作频率相对较低,只有一个最佳工作频率点(200Hz左右),输出流量和压力分别为3.0ml/min和9.5KPa。这说明通过阀片的设计可提高药用微型压电泵的最佳工作频率及输出能力、减小输出脉动,以往认为有阀压电泵只能在低频状态工作的观点是错误的。     

U937细胞ClqR介导对酵母多糖颗粒的吞噬及其与FcγR的协同作用

在证实了人Ｍφ系Ｕ９３７细胞ＣｌｑＲ在生理离子强度（Ｉ０．１５）下可与１２５Ｉ－Ｃｌｑ结合的基础上研究了ＣｌｑＲ对Ｕ９３７细胞吞噬酵母多糖颗粒（Ｚ）的调节作用。该细胞不吞噬Ｚ，但可吞噬Ｃｌｑ或ＩｑＧ调理的Ｚ（ＣＺ、ＩＺ），若以Ｃｌｑ和ＩｇＧ调理（ＩＣＺ），吞噬指数分别是ＣＺ和ＩＺ的６倍和２．５倍。将调理颗粒热灭活，或加入兔抗人ＣｌｑＦ（ａｂ’）２，或以高浓度Ｃｌｑ或抗人ＣｌｑＲｍＡｂＥ８预处理Ｕ９３７细胞，均可不同程度地抑制对ＣＺ或ＩＣＺ的吞噬，但Ｃｌｑ预处理却使对ＩＺ和Ｚ的吞噬增强。资料表明，Ｕ９３７细胞通过ＣｌｑＲ介导对酵母多糖颗粒的吞噬，且与ＦｃγＲ有协同作用。     

新结构药品输送压电泵的泵送特性

提出了一种新式的双压电薄膜驱动串联压电泵 ,并对其输出性能进行了试验研究。压电泵采用多层粘结的圆片结构 ,包括 PMMA(聚甲基丙烯酸甲酯 )泵体、两个独立驱动的压电薄膜驱动器和三个弹性薄膜阀片。两个压电薄膜驱动器交叉工作 (即驱动相位相差 180°) ,相当于两个独立的单腔体泵串联工作 ,使该泵具有较高的输出压力和流量。泵的输出性能取决于压电薄膜几何参数。利用厚度 0 .18m m、直径 5 0 mm的压电薄膜制作的试验样机能以两种不同的方式工作 :直接输液 (药液流经泵腔 )和间接输液 (药液不经过泵腔 ,利用空气压力使密封容器内流体输出 )。两种工作方式的频率响应特性差别很大 ,间接输液的高频性能好 ,而直接输液的低频性能好。在驱动电压 80 v、频率为 2 0 Hz时 ,实际测得间接 /直接输液的最大流量分别为 2 2 0、35 ml/ m in,最大出口压力分别为 14、2 1KPa。