• 1 Mast cells in surgically resected appendices. 复制标题 收藏 收藏

    【手术切除的阑尾中的肥大细胞。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Mysorekar VV,Chanda S,Dandeka CP
    BACKGROUND & AIMS: :Mast cells are known to be effector cells in various inflammatory reactions, but their role in appendicitis is unclear. The present study was undertaken to investigate the extent of mast cell involvement in appendicitis and evaluate their possible role. A total of 150 appendices including normal and inflamed appendices, were assessed for their histological changes and density of neutrophil, lymphocyte and eosinophil infiltration. The mast cells were counted in 1% toluidine blue-stained sections. It was found that eosinophil counts in all the layers were significantly low in normal appendices (P<0.01) and in chronic appendicitis (P<0.1) as compared to acute appendicitis. Mast cell counts were lowest in normal appendices, significantly higher in acute appendicitis (P<0.01) and highest in chronic appendicitis (P<0.001). Obstruction due to faecoliths or parasites were seen in only 20.1% and 2.1% of the inflamed appendices respectively. Hence a Type I hypersensitivity reaction with release of mediators by mast cells might be another triggering factor for the sequence of events leading to appendicitis.
    背景与目标: :已知肥大细胞是各种炎症反应中的效应细胞,但它们在阑尾炎中的作用尚不清楚。本研究旨在研究肥大细胞参与阑尾炎的程度并评估其可能的作用。共评估了150个阑尾,包括正常和发炎的阑尾的组织学变化以及中性粒细胞,淋巴细胞和嗜酸性粒细胞浸润的密度。肥大细胞在1%甲苯胺蓝染色的切片中计数。发现与急性阑尾炎相比,正常阑尾(P <0.01)和慢性阑尾炎(P <0.1)所有层的嗜酸性粒细胞计数均显着较低。正常阑尾中的肥大细胞计数最低,急性阑尾炎中的肥大细胞计数显着更高(P <0.01),而慢性阑尾炎中的肥大细胞计数最高(P <0.001)。分别在发炎的阑尾中仅见20.1%和2.1%的因粪便或寄生虫引起的阻塞。因此,肥大细胞释放介体的I型超敏反应可能是导致阑尾炎的一系列事件的另一个触发因素。
  • 【刺猬组织果蝇腹部表皮细胞的模式和极性。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Struhl G,Barbash DA,Lawrence PA
    BACKGROUND & AIMS: The abdomen of adult Drosophila, like that of other insects, is formed by a continuous epithelium spanning several segments. Each segment is subdivided into an anterior (A) and posterior (P) compartment, distinguished by activity of the selector gene engrailed (en) in P but not A compartment cells. Here we provide evidence that Hedgehog (Hh), a protein secreted by P compartment cells, spreads into each A compartment across the anterior and the posterior boundaries to form opposing concentration gradients that organize cell pattern and polarity. We find that anteriorly and posteriorly situated cells within the A compartment respond in distinct ways to Hhthey express different combinations of genes and form different cell types. They also form polarised structures that, in the anterior part, point down the Hh gradient and, in the posterior part, point up the gradient - therefore all structures point posteriorly. Finally, we show that ectopic Hh can induce cells in the middle of each A compartment to activate en. Where this happens, A compartment cells are transformed into an ectopic P compartment and reorganise pattern and polarity both within and around the transformed tissue. Many of these results are unexpected and lead us to reassess the role of gradients and compartments in patterning insect segments.

    背景与目标: 像其他昆虫一样,成年果蝇的腹部由跨越几个部分的连续上皮形成。每个部分细分为前(A)和后(P)隔室,其区别在于P(A)中夹带(en)而不是A隔室细胞的选择基因的活性。在这里,我们提供的证据表明,刺猬(Hh)是P隔室细胞分泌的一种蛋白质,它通过前后边界扩散到每个A隔室中,从而形成组织细胞模式和极性的相对浓度梯度。我们发现A区隔中的前向和后向细胞以不同的方式对Hhthey​​表达不同的基因组合并形成不同的细胞类型作出反应。它们还形成极化结构,该结构在前部指向Hh梯度,而在后部指向Hh梯度-因此所有结构都向后指向。最后,我们表明异位Hh可以诱导每个A区中间的细胞激活en。在发生这种情况的地方,A隔室细胞被转化为异位P隔室,并在转化组织内部和周围重新组织模式和极性。这些结果中有许多是出乎意料的,使我们重新评估了梯度和区室在图案化昆虫片段中的作用。

  • 【雌二醇通过上调Fas和Fas配体表达来增加人冠状动脉内皮细胞的凋亡。】 复制标题 收藏 收藏
    DOI:10.1210/jc.2006-1225 复制DOI
    作者列表:Seli E,Guzeloglu-Kayisli O,Cakmak H,Kayisli UA,Selam B,Arici A
    BACKGROUND & AIMS: CONTEXT:In animal models, estrogen inhibits atherogenesis by inhibiting many of the early steps of atherosclerotic plaque formation. However, the lack of cardioprotective effect by postmenopausal hormone replacement therapy and possible increase in cardiovascular events observed during the first year after the initiation of hormone replacement therapy may suggest that once the plaque is formed, estrogen may have additional effects that may counteract its beneficial outcomes. Indeed, the effect of estrogen on plaque stability has not been identified. OBJECTIVE:We hypothesized that 17beta-estradiol (E2) may cause increased apoptosis in human coronary artery endothelial cells (HCAECs). This effect would explain an adverse effect on plaque stability in vivo. INTERVENTION(S) AND MAIN OUTCOME MEASURE(S):The effect of E2 on apoptosis, cell proliferation, and expression of proapoptotic molecules Fas and Fas ligand (FasL) in cultured HCAECs was evaluated. RESULTS:HCAECs in culture treated with E2 showed an increase in DNA strand breaks and nuclear fragmentation indicative of apoptosis. E2 treatment also induced a significant concentration-dependent increase in Fas mRNA and protein expressions in HCAECs. Moreover, the expression of FasL mRNA and secretion of FasL protein by HCAECs were enhanced in response to E2 treatments. CONCLUSIONS:E2 increases the apoptosis in cultured HCAECs. Enhanced Fas and FasL expressions in response to E2 suggest that activation of the Fas/FasL pathway may be a mediator of the proapoptotic effects of E2 in these cells.
    背景与目标: 背景:在动物模型中,雌激素通过抑制动脉粥样硬化斑块形成的许多早期步骤来抑制动脉粥样硬化。但是,绝经后激素替代疗法缺乏心脏保护作用,并且在开始激素替代疗法后的第一年内观察到的心血管事件可能增加,这表明一旦形成斑块,雌激素可能会产生额外的作用,从而抵消其有益结果。实际上,尚未确定雌激素对斑块稳定性的作用。
    目的:我们假设17β-雌二醇(E2)可能导致人冠状动脉内皮细胞(HCAEC)凋亡增加。该作用将解释对体内斑块稳定性的不利影响。
    干预和主要观察指标:评估了E2对培养的HCAEC中细胞凋亡,细胞增殖以及促凋亡分子Fas和FasL配体(FasL)表达的影响。
    结果:用E2处理的培养物中的HCAECs显示DNA链断裂的增加和核碎裂指示凋亡。 E2处理还诱导了HCAECs Fas mRNA和蛋白表达的浓度依赖性显着增加。而且,响应于E2处理,HCAECs的FasL mRNA的表达和FasL蛋白的分泌得到增强。
    结论:E2增加了培养的HCAECs的细胞凋亡。响应E2增强的Fas和FasL表达表明Fas / FasL途径的激活可能是这些细胞中E2促凋亡作用的介质。
  • 【白介素-1对大鼠培养的Ito细胞的松弛作用。】 复制标题 收藏 收藏
    DOI:10.1002/hep.510250618 复制DOI
    作者列表:Sakamoto M,Ueno T,Sugawara H,Torimura T,Tsuji R,Sujaku K,Sata M,Tanikawa K
    BACKGROUND & AIMS: Interleukin-1beta (IL-1beta) is closely involved in liver disorders. IL-1beta produces nitric oxide (NO) in vascular smooth muscle cells and relaxes vascular smooth muscle via cyclic guanosine 3',5'-monophosphate (cGMP). In this study, we evaluated the relaxing effect of IL-1beta on cultured Ito cells. Ito cells were isolated from the livers of male Wistar rats and cultured for 24 hours. Immunolocalization of inducible nitric oxide synthase (iNOS) and cGMP and intensity of fluorescence of cGMP were examined using a confocal laser microscope. Ito cells were treated with 0, 200, and 1,000 pmol/L IL-1beta, and the intracellular cGMP concentration was measured after 12 hours. Moreover, Ito cells treated with 200 and 1,000 pmol/L IL-1beta and not treated with IL-1beta were observed over 12 hours, and the area of the same Ito cell was compared before and after the addition of IL-1beta. Next, effects of N(G)-monomethyl-L-arginine (L-NMMA) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) on Ito cell relaxation by IL-1beta treatment were examined. In Ito cells, immunofluorescence of iNOS was observed, and fluorescent intensity of cGMP increased after addition of IL-1beta. Intracellular cGMP concentration increased dose-dependently after addition of IL-1beta. Cell area significantly increased in the IL-1beta-treated group compared with the untreated group. Relaxation of Ito cells by IL-1beta treatment was inhibited by L-NMMA in a dose-dependent manner, but was enhanced by SNAP. These results indicate that IL-1beta produces NO in cultured Ito cells and relaxes the cells via cGMP.

    背景与目标: 白介素-1β(IL-1beta)与肝脏疾病密切相关。 IL-1β在血管平滑肌细胞中产生一氧化氮(NO),并通过环状鸟苷3',5'-单磷酸(cGMP)松弛血管平滑肌。在这项研究中,我们评估了IL-1β对培养的Ito细胞的松弛作用。从雄性Wistar大鼠的肝脏中分离出Ito细胞,并培养24小时。使用共聚焦激光显微镜检查诱导型一氧化氮合酶(iNOS)和cGMP的免疫定位和cGMP的荧光强度。用0、200和1,000 pmol / L IL-1beta处理Ito细胞,并在12小时后测量细胞内cGMP浓度。此外,在12小时内观察到用200和1,000 pmol / L IL-1beta处理且未用IL-1beta处理的Ito细胞,并且在添加IL-1beta之前和之后比较了同一个Ito细胞的面积。接下来,研究了N(G)-单甲基-L-精氨酸(L-NMMA)和S-亚硝基-N-乙酰基-DL-青霉胺(SNAP)对通过IL-1beta处理的Ito细胞松弛的影响。在Ito细胞中,观察到iNOS的免疫荧光,添加IL-1β后cGMP的荧光强度增加。加入IL-1beta后,细胞内cGMP浓度呈剂量依赖性增加。与未治疗组相比,IL-1β治疗组的细胞面积显着增加。 L-1NMMA以剂量依赖的方式抑制了通过IL-1beta处理的Ito细胞的松弛,但被SNAP增强了。这些结果表明IL-1β在培养的Ito细胞中产生NO,并通过cGMP使细胞松弛。

  • 【镉通过一系列引起细胞毒性的三波活性氧来影响烟草细胞。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-3040.2006.01571.x 复制DOI
    作者列表:Garnier L,Simon-Plas F,Thuleau P,Agnel JP,Blein JP,Ranjeva R,Montillet JL
    BACKGROUND & AIMS: :Cadmium is suspected to exert its toxic action on cells through oxidative damage. However, the transition metal is unable to directly generate reactive oxygen species (ROS) via redox reactions with molecular oxygen in a biological environment. Here, we show that bright yellow-2 (BY-2) tobacco cells exposed to millimolar concentrations of CdCl(2) developed cell death within 2-3 h. The death process was preceded by two successive waves of ROS differing in their nature and subcellular localization. Firstly, these consisted in the transient NADPH oxidase-dependent accumulation of H(2)O(2) followed by the accumulation of O(2) (-*) in mitochondria. A third wave of ROS consisting in fatty acid hydroperoxide accumulation was concomitant with cell death. Accumulation of H(2)O(2) was preceded by an increase in cytosolic free calcium concentration originating from internal pools that was essential to activate the NADPH oxidase. The cell line gp3, impaired in NADPH oxidase activity, and that was unable to accumulate H(2)O(2) in response to Cd(2+), was nevertheless poisoned by the metal. Therefore, this first wave of ROS was not sufficient to trigger all the cadmium-dependent deleterious effects. However, we show that the accumulation of O(2) (-*) of mitochondrial origin and membrane peroxidation are key players in Cd(2+)-induced cell death.
    背景与目标: :镉被怀疑通过氧化损伤对细胞产生毒性作用。然而,在生物环境中,过渡金属不能通过与分子氧的氧化还原反应直接产生活性氧(ROS)。在这里,我们显示暴露于毫摩尔浓度的CdCl(2)的亮黄色2(BY-2)烟草细胞在2-3小时内发展出细胞死亡。死亡过程之前是连续两次的ROS,其性质和亚细胞定位各不相同。首先,这些包括线粒体中H(2)O(2)的瞬时NADPH氧化酶依赖性积累,然后是线粒体中O(2)(-*)的积累。 ROS的第三波涉及脂肪酸氢过氧化物的积累,并伴随着细胞死亡。 H(2)O(2)的积累之前是来自内部池的胞质游离钙浓度的增加,这对于激活NADPH氧化酶是必不可少的。然而,细胞系gp3在NADPH氧化酶活性中受损,并且无法响应Cd(2)积聚H(2)O(2),但仍被金属中毒。因此,ROS的第一波不足以触发所有依赖镉的有害作用。但是,我们表明,线粒体起源的O(2)(-*)积累和膜过氧化是Cd(2)诱导的细胞死亡的关键因素。
  • 【通过过继转移CD4抗肿瘤T细胞杀死原位大鼠腺癌13762需要细胞表面MHC II类分子的肿瘤表达。】 复制标题 收藏 收藏
    DOI:10.1006/cimm.1997.1122 复制DOI
    作者列表:Frey AB,Cestari S
    BACKGROUND & AIMS: CD4+ anti-tumor T cells reactive with rat adenocarcinoma 13762 kill tumor in vitro and cause regression of tumor in vivo. The role of various host immune cells in CD4+ T-cell-mediated tumor elimination in vivo was investigated by adoptive transfer of anti-tumor T cell clones to recipients that were selectively depleted of individual immune cell types. By these means, macrophages and NK cells were found to be required for tumor killing. Depletion of host CD4+ T cells, CD8+ T cells, or neutrophils was without effect on tumor elimination by anti-tumor T cells. An essential role for antigen receptor-negative NK cells is likely dependent upon secretion of IFN-gamma from NK cells since treatment of tumor recipients with anti-IFN-gamma antibody prior to adoptive transfer and tumor challenge abrogated T cell killing, resulting in progressive tumor growth. Viability of adenocarcinoma 13762 or anti-tumor T cells was unaffected by treatment with either IFN-gamma or anti-IFN-gamma antibody in vitro, but cell surface MHC class II expression was induced in tumor cells by exposure to IFN-gamma. In addition, tumor cells were isolated from tumor-bearing animals by absorption using anti-MHC class II antibody, demonstrating that 13762 tumor expresses cell surface MHC class II antigens in situ. However, if hosts were depleted of NK cells before tumor challenge, MHC class II+ tumor was not recovered. Collectively these results suggest that adenocarcinoma 13762 is eliminated by MHC class II-restricted CD4+ T cells by direct tumor killing.

    背景与目标: 与大鼠腺癌13762反应的CD4抗肿瘤T细胞在体外杀死肿瘤并在体内引起肿瘤消退。通过将抗肿瘤T细胞克隆过继转移到选择性清除了个体免疫细胞类型的受体上,研究了各种宿主免疫细胞在体内CD4 T细胞介导的肿瘤消除中的作用。通过这些手段,发现杀死肿瘤需要巨噬细胞和NK细胞。宿主CD4 T细胞,CD8 T细胞或嗜中性白细胞的耗竭对抗肿瘤T细胞对肿瘤的消除没有影响。抗原受体阴性NK细胞的重要作用可能取决于NK细胞分泌IFN-γ,因为在过继转移和肿瘤攻击之前用抗IFN-γ抗体治疗肿瘤受体可以消除T细胞杀伤,从而导致进行性肿瘤生长。体外用IFN-γ或抗IFN-γ抗体治疗不会影响腺癌13762或抗肿瘤T细胞的存活率,但通过暴露于IFN-γ诱导了肿瘤细胞的细胞表面MHC II类表达。另外,通过使用抗MHC II类抗体的吸收从荷瘤动物中分离出肿瘤细胞,表明13762肿瘤原位表达细胞表面MHC II类抗原。但是,如果宿主在肿瘤攻击前已耗尽NK细胞,则无法恢复MHC II类肿瘤。这些结果共同表明,通过直接杀死肿瘤,MHC II类限制性CD4 T细胞可消除13762腺癌。

  • 【垂体激素调节胸腺细胞和胸腺上皮细胞之间的细胞间相互作用。】 复制标题 收藏 收藏
    DOI:10.1016/s0165-5728(97)00031-3 复制DOI
    作者列表:de Mello-Coelho V,Villa-Verde DM,Dardenne M,Savino W
    BACKGROUND & AIMS: The thymic microenvironment plays a key role in the intrathymic T-cell differentiation. It is composed of a tridimensional network of epithelial cells whose physiology is controlled by extrinsic circuits such as neuroendocrine axes. Herein we show that the expression of extracellular matrix ligands and receptor by cultured thymic epithelial cells is upregulated by prolactin (PRL) and growth hormone (GH), the latter apparently occurring via insulin-like growth factor I (IGF-I). Thymocyte release from the lymphoepithelial complexes, thymic nurse cells, as well as the reconstitution of these complexes are enhanced by PRL, GH or IGF-I. Treatment of a mouse thymic epithelial cell line with these hormones induced an increase in thymocyte adhesion, an effect significantly prevented in the presence of antibodies to fibronectin, laminin or respective receptors VLA-5 and VLA-6. Our data suggest that the in vitro changes in thymocyte/thymic epithelial cell interactions induced by pituitary hormones are partially mediated by the enhancement of extracellular matrix ligands and receptors.

    背景与目标: 胸腺微环境在胸腺内T细胞分化中起关键作用。它由上皮细胞的三维网络组成,其上皮细胞的生理受到外在回路(如神经内分泌轴)的控制。本文中我们显示,培养的胸腺上皮细胞的细胞外基质配体和受体的表达被催乳素(PRL)和生长激素(GH)上调,后者显然是通过胰岛素样生长因子I(IGF-1)发生的。 PRL,GH或IGF-I增强了从淋巴上皮复合物,胸腺护士细胞释放胸腺细胞以及这些复合物的重构。用这些激素处理小鼠胸腺上皮细胞系可诱导胸腺细胞粘附增加,在存在针对纤连蛋白,层粘连蛋白或相应受体VLA-5和VLA-6的抗体的情况下,该作用被显着阻止。我们的数据表明,垂体激素诱导的胸腺细胞/胸腺上皮细胞相互作用的体外变化部分由细胞外基质配体和受体的增强介导。

  • 【创伤弧菌溶血素对大鼠腹腔肥大细胞的细胞溶解作用。】 复制标题 收藏 收藏
    DOI:10.1099/00222615-32-1-39 复制DOI
    作者列表:Yamanaka H,Sugiyama K,Furuta H,Miyoshi S,Shinoda S
    BACKGROUND & AIMS: :The mode of action of Vibrio vulnificus haemolysin (VVH) on mast cells from the peritoneal cavity of the rat was examined. VVH induced histamine release, and damage to the mast cells, in a dose-dependent fashion. When 1 microgram of VVH was added to c. 10(5) mast cells at 37 degrees C, histamine release was observed after a lag period of 5-10 s, and was complete within 5 min. The action was temperature-dependent, and was not induced at 4 degrees C. Disodium cromoglycate, a membrane stabiliser for mast cells, inhibited the histamine release significantly, but the effect was not dose-dependent. Moreover, leakage of lactate dehydrogenase from VVH-treated mast cells was observed. These results suggest that VVH acts on the cell membrane of mast cells and is cytolytic.
    背景与目标: :检查了创伤弧菌溶血素(VVH)对大鼠腹膜腔肥大细胞的作用方式。 VVH以剂量依赖的方式诱导组胺释放和对肥大细胞的损害。当将1微克VVH添加到c中时。 10(5)肥大细胞在37摄氏度下,经过5-10 s的滞后时间后观察到组胺释放,并在5分钟内完成。该作用是温度依赖性的,并且在4℃下没有诱导。肥大细胞的膜稳定剂色甘酸二钠明显抑制组胺的释放,但作用不是剂量依赖性的。此外,观察到乳酸脱氢酶从VVH处理的肥大细胞中泄漏。这些结果表明,VVH作用于肥大细胞的细胞膜并具有溶细胞作用。
  • 【蛋白激酶D2通过NF-κB介导未转化的人结肠上皮细胞中溶血磷脂酸诱导的白介素8的产生。】 复制标题 收藏 收藏
    DOI:10.1152/ajpcell.00308.2006 复制DOI
    作者列表:Chiu TT,Leung WY,Moyer MP,Strieter RM,Rozengurt E
    BACKGROUND & AIMS: :The signaling pathways mediating lysophosphatidic acid (LPA)-stimulated PKD(2) activation and the potential contribution of PKD(2) in regulating LPA-induced interleukin 8 (IL-8) secretion in nontransformed, human colonic epithelial NCM460 cells were examined. Treatment of serum-deprived NCM460 cells with LPA led to a rapid and striking activation of PKD(2), as measured by in vitro kinase assay and phosphorylation at the activation loop (Ser706/710) and autophosphorylation site (Ser876). PKD(2) activation induced by LPA was abrogated by preincubation with selective PKC inhibitors GF-I and Ro-31-8220 in a dose-dependent manner. These inhibitors did not have any direct inhibitory effect on PKD(2) activity. LPA induced a striking increase in IL-8 production and stimulated NF-kappaB activation, as measured by NF-kappaB-DNA binding, NF-kappaB-driven luciferase reporter activity, and IkappaBalpha phosphorylation. PKD(2) gene silencing utilizing small interfering RNAs targeting distinct PKD(2) sequences dramatically reduced LPA-stimulated NF-kappaB promoter activity and IL-8 production. PKD(2) activation is a novel early event in the biological action of LPA and mediates LPA-stimulated IL-8 secretion in NCM460 cells through a NF-kappaB-dependent pathway. Our results demonstrate, for the first time, the involvement of a member of the PKD family in the production of IL-8, a potent proinflammatory chemokine, by epithelial cells.
    背景与目标: :审查了介导溶血磷脂酸(LPA)刺激的PKD(2)激活和PKD(2)在调节LPA诱导的非转化型人结肠上皮NCM460细胞中LPA诱导的白介素8(IL-8)分泌中的潜在作用。用体外LPA处理血清缺乏的NCM460细胞会导致PKD(2)迅速而惊人的活化,这是通过体外激酶测定和活化环(Ser706 / 710)和自磷酸化位点(Ser876)的磷酸化来测量的。通过与选择性PKC抑制剂GF-1和Ro-31-8220呈剂量依赖性方式进行预孵育,可以消除LPA诱导的PKD(2)激活。这些抑制剂对PKD(2)活性没有任何直接的抑制作用。如通过NF-κB-DNA结合,NF-κB驱动的萤光素酶报道分子活性和IkappaBalpha磷酸化所测量,LPA诱导IL-8产量显着增加并刺激NF-κB活化。 PKD(2)基因沉默利用针对不同的PKD(2)序列的小干扰RNA,大大降低了LPA刺激的NF-κB启动子活性和IL-8的产生。 PKD(2)激活是LPA的生物学作用中的一个新的早期事件,并通过NF-κB依赖性途径介导LCM刺激NCM460细胞中IL-8的分泌。我们的结果首次证明,上皮细胞参与了PKD家族成员参与IL-8(一种有效的促炎趋化因子)的生产。
  • 【缺氧条件下的肿瘤基质细胞相互作用通过肝细胞生长因子/ c-Met途径增加了胰腺癌细胞的侵袭性。】 复制标题 收藏 收藏
    DOI:10.1002/ijc.22178 复制DOI
    作者列表:Ide T,Kitajima Y,Miyoshi A,Ohtsuka T,Mitsuno M,Ohtaka K,Koga Y,Miyazaki K
    BACKGROUND & AIMS: :The hypoxic environment in tumor is reported to play an important role in pancreatic cancer progression. The interaction between stromal and cancer cells also contributes to the malignant behavior of pancreatic cancer. In the present study, we investigated whether hypoxic stimulation affects stromal as well as pancreatic cancer cells. Our findings demonstrated that hypoxia remarkably elevated the HIF-1alpha expression in both pancreatic cancer (PK8) and fibroblast cells (MRC5). Hypoxic stimulation accelerated the invasive activity of PK8 cells, and invasiveness was thus further accelerated when the hypoxic PK8 cells were cultured with conditioned medium prepared from hypoxic MRC5 cells (hypoxic conditioned medium). MMP-2, MMP-7, MT1-MMP and c-Met expressions were increased in PK8 cells under hypoxia. Hypoxic stimulation also increased the hepatocyte growth factor (HGF) secretion from MRC5 cells, which led to an elevation of c-Met phosphorylation in PK8 cells. Conversely, the elevated cancer invasion, MMP activity and c-Met phosphorylation of PK8 cells were reduced by the removal of HGF from hypoxic conditioned medium. In immunohistochemical study, the HIF-1alpha expression was observed in surrounding stromal as well as pancreatic cancer cells, thus indicating hypoxia exists in both of cancer and stromal cells. Moreover, the stromal HGF expression was found to significantly correlate with not only the stromal HIF-1alpha expression but also the c-Met expression in cancer cells. These results indicate that the hypoxic environment within stromal as well as cancer cells activates the HGF/c-Met system, thereby contributing to the aggressive invasive features of pancreatic cancer.
    背景与目标: :据报道肿瘤中的低氧环境在胰腺癌的进展中起重要作用。基质细胞与癌细胞之间的相互作用也有助于胰腺癌的恶性行为。在本研究中,我们调查了低氧刺激是否影响基质以及胰腺癌细胞。我们的发现表明,低氧显着提高了胰腺癌(PK8)和成纤维细胞(MRC5)中HIF-1alpha的表达。低氧刺激加速了PK8细胞的侵袭活性,因此,当用由低氧MRC5细胞制备的条件培养基(低氧条件培养基)培养低氧PK8细胞时,侵袭性进一步加快。在缺氧条件下,PK8细胞中的MMP-2,MMP-7,MT1-MMP和c-Met表达增加。缺氧刺激还增加了MRC5细胞的肝细胞生长因子(HGF)分泌,从而导致PK8细胞中c-Met磷酸化的升高。相反,通过从低氧条件培养基中去除HGF,可以降低PK8细胞的癌浸润,MMP活性和c-Met磷酸化水平的升高。在免疫组织化学研究中,在周围的基质细胞和胰腺癌细胞中均观察到了HIF-1alpha的表达,因此表明在癌细胞和基质细胞中均存在缺氧。此外,发现基质HGF表达不仅与癌细胞中的基质HIF-1α表达而且与c-Met表达显着相关。这些结果表明基质以及癌细胞内的低氧环境激活了HGF / c-Met系统,从而促进了胰腺癌的侵袭性侵袭性。
  • 【缓慢失活的钙电流在分泌降钙素的细胞中充当钙传感器。】 复制标题 收藏 收藏
    DOI:10.1016/0014-5793(90)81048-s 复制DOI
    作者列表:Scherübl H,Schultz G,Hescheler J
    BACKGROUND & AIMS: :Calcitonin (CT)-secreting cells (C-cells) are remarkably sensitive to changes in the extracellular Ca2+ concentration. In order to detect the mechanism by which C-cells monitor Ca2+, we compared a C-cell line responding to Ca2+ (rMTC cells) with another one known to have a defect in this Ca2+ signal transduction (TT cells). Rises of the Ca2+ concentration caused rMTC cells to depolarize and/or elicited spontaneous action potentials. Under voltage-clamp conditions, rMTC cells showed a slowly decaying Ca2+ inward current which was sensitive to dihydropyridines but not to Ni2+ at a low concentration. In contrast, the 'defective' TT cells neither depolarized nor fired action potentials with high Ca2+; they only exhibited an Ni2(+)-sensitive, transient Ca2+ current. The data strongly suggest that the slowly inactivating Ca2+ current is a prerequisite for Ca2(+)-sensitivity of C-cells and that fast inactivating channels are not sufficient to act as sensors of the extracellular Ca2+ concentration.
    背景与目标: :分泌降钙素(CT)的细胞(C细胞)对细胞外Ca2浓度的变化非常敏感。为了检测C细胞监控Ca2的机制,我们将响应Ca2的C细胞系(rMTC细胞)与已知在Ca2信号转导中存在缺陷的另一种细胞(TT细胞)进行了比较。 Ca 2浓度的升高引起rMTC细胞去极化和/或引起自发动作电位。在电压钳制条件下,rMTC细胞显示出缓慢衰减的Ca2内向电流,该电流对二氢吡啶敏感,但对低浓度的Ni2不敏感。相反,“缺陷”的TT细胞既没有去极化也没有激发具有高Ca2的动作电位。它们仅表现出对Ni2()敏感的瞬态Ca2电流。数据强烈表明,缓慢失活的Ca2电流是C细胞对Ca2()敏感性的先决条件,而快速失活的通道不足以充当细胞外Ca2浓度的传感器。
  • 【在使用电纺聚合物支架的三维培养系统中,鼠胚胎干细胞的成脂作用。】 复制标题 收藏 收藏
    DOI:10.1016/j.biomaterials.2006.08.052 复制DOI
    作者列表:Kang X,Xie Y,Powell HM,James Lee L,Belury MA,Lannutti JJ,Kniss DA
    BACKGROUND & AIMS: :A mechanistic understanding of adipose tissue differentiation is critical for the treatment and prevention of obesity and type 2 diabetes. Conventional in vitro models of adipogenesis are preadipocytes or freshly isolated adipocytes grown in two-dimensional (2D) cultures. Optimal results using in vitro tissue culture models can be expected only when adipocyte models closely resemble adipose tissue in vivo. Thus the design of an in vitro three-dimensional (3D) model which faithfully mimics the in vivo environment is needed to effectively study adipogenesis. Pluripotent embryonic stem (ES) cells are a self-renewing cell type that can readily be differentiated into adipocytes. In this study, a 3D culture system was developed to mimic the geometry of adipose tissue in vivo. Murine ES cells were seeded into electrospun polycaprolactone scaffolds and differentiated into adipocytes in situ by hormone induction as demonstrated using a battery of gene and protein expression markers along with the accumulation of neutral lipid droplets. Insulin-responsive Akt phosphorylation, and beta-adrenergic stimulation of cyclic AMP synthesis were demonstrated in ES cell-derived adipocytes. Morphologically, ES cell-derived adipocytes resembled native fat cells by scanning electron and phase contrast microscopy. This tissue engineered ES cell-matrix model has potential uses in drug screening and other therapeutic developments.
    背景与目标: :对脂肪组织分化的机械理解对于肥胖症和2型糖尿病的治疗和预防至关重要。脂肪形成的常规体外模型是在二维(2D)培养物中生长的前脂肪细胞或新鲜分离的脂肪细胞。仅当脂肪细胞模型与体内脂肪组织非常相似时,才能期望使用体外组织培养模型获得最佳结果。因此,需要忠实地模拟体内环境的体外三维(3D)模型的设计才能有效地研究脂肪形成。多能胚胎干(ES)细胞是一种自我更新的细胞类型,可以很容易地分化为脂肪细胞。在这项研究中,开发了一种3D培养系统来模拟体内脂肪组织的几何形状。将鼠ES细胞接种到电纺聚己内酯支架中,并通过激素诱导原位分化为脂肪细胞,如使用一系列基因和蛋白质表达标志物以及中性脂质滴的积累所证明的。在ES细胞衍生的脂肪细胞中证实了胰岛素反应性Akt磷酸化和β-肾上腺素能刺激环状AMP合成。形态上,通过扫描电子和相差显微镜,ES细胞来源的脂肪细胞类似于天然脂肪细胞。这种组织工程化的ES细胞基质模型在药物筛选和其他治疗发展中具有潜在用途。
  • 【骨髓嵌合体小鼠的肿瘤浸润基质细胞的制备和功能分析。】 复制标题 收藏 收藏
    DOI:10.1111/j.1348-0421.2006.tb03830.x 复制DOI
    作者列表:Ishigaki H,Yamamoto Y,Ishida H,Kajino K,Itoh Y,Fujiyama Y,Ogasawara K
    BACKGROUND & AIMS: :Tumor-infiltrating stroma cells (TISC) as well as tumors themselves are thought to be involved in tumor-related immunosuppression, which is one of the critical mechanisms of tumor escape from immune surveillance. However, preparation of TISC is difficult because of the small proportion of TISC in established tumors. Thus, the cells thought to be involved in tumor-related immunosuppression are generally prepared from spleens or draining lymph nodes in tumor-bearing mice. In this study, we developed a method for directly preparing TISC from established tumors in order to analyze their function. Using green fluorescent protein (GFP) transgenic (Tg) mice and C57BL/6 mice transplanted with bone marrow (BM) cells of GFPTg mice, we detected three subpopulations of TISC: one is compatible with immature myeloid cells (ImC) derived from BM and the two other subpopulations, CD11b(+) cells and CD11b(-) cells, do not originate from BM. The TISC including these subpopulations but not each subpopulation independently after culturing with tumors in the presence of GM-CSF could suppress T cell proliferation induced by anti-CD3. In our system, tumors did not inhibit T cell responses directly, but unknown factors from tumors affected immunosuppression by TISC.
    背景与目标: :肿瘤浸润基质细胞(TISC)以及肿瘤本身都被认为与肿瘤相关的免疫抑制有关,这是肿瘤逃避免疫监视的关键机制之一。然而,由于在已建立的肿瘤中TISC的比例很小,因此TISC的制备是困难的。因此,通常被认为与肿瘤相关的免疫抑制有关的细胞是从荷瘤小鼠的脾脏或引流淋巴结中制备的。在这项研究中,我们开发了一种从已建立的肿瘤中直接制备TISC的方法,以分析其功能。使用绿色荧光蛋白(GFP)转基因(Tg)小鼠和移植有GFPTg小鼠骨髓(BM)细胞的C57BL / 6小鼠,我们检测到TISC的三个亚群:一个与源自BM的未成熟髓样细胞(ImC)相容。其他两个亚群CD11b()细胞和CD11b(-)细胞并非源自BM。在存在GM-CSF的情况下与肿瘤培养后,TISC包括这些亚群,但并非每个亚群独立地抑制由抗CD3诱导的T细胞增殖。在我们的系统中,肿瘤并未直接抑制T细胞反应,但来自肿瘤的未知因素影响了TISC的免疫抑制。
  • 【B细胞慢性淋巴细胞性白血病患者T细胞中的信号分子和细胞因子产生:氟达拉滨和alemtuzumab治疗的长期效果。】 复制标题 收藏 收藏
    DOI:10.1080/10428190600565503 复制DOI
    作者列表:Kiaii S,Choudhury A,Mozaffari F,Rezvany R,Lundin J,Mellstedt H,Osterborg A
    BACKGROUND & AIMS: :Fludarabine and alemtuzumab are routinely used for treatment of B-cell chronic lymphocytic leukemia (B-CLL). The present study aimed to compare the expression of signaling molecules and cytokine production by T cells of B-CLL patients in long-term unmaintained remission/plateau phase following fludarabine or alemtuzumab treatment with that of indolent/untreated B-CLL patients and healthy donors. The frequency and intensity of TCR-CD3zeta chain, p56lck, p59fyn, ZAP-70, PI3-kinase and interferon (IFN)-gamma/interleukin (IL)-4 production in CD4 and CD8 T cells was examined by flow cytometry. T-cell function was assessed by stimulation with purified protein derivative (PPD) and phytohemagglutinin (PHA). Despite a reduction in number, the expression of IFN-gamma/IL-4 in T-cells in patients was significantly higher than in healthy donors. The intensity of most signaling molecules in treated patients was relatively unaffected vs. healthy donors but lower than untreated-indolent patients. However, the total number of T cells which expressed each of the signaling molecules was decreased in patients, with no difference between fludarabine- and alemtuzumab-treated patients. The T-cell response to PHA but not PPD was reduced in treated patients. The results suggest that, despite some alterations in signaling molecules and a reduction in T-cell number, overall T-cell functions may be relatively well preserved long-term after treatment with fludarabine and alemtuzumab.
    背景与目标: 氟达拉滨和阿仑单抗通常用于治疗B细胞慢性淋巴细胞性白血病(B-CLL)。本研究旨在比较氟达拉滨或alemtuzumab治疗后长期未维持的缓解/高原期的B-CLL患者的信号分子的表达和T细胞的细胞因子产生与惰性/未经治疗的B-CLL患者和健康供体的长期比较。通过流式细胞术检测TCR-CD3zeta链,p56lck,p59fyn,ZAP-70,PI3-激酶和干扰素(IFN)-γ/白介素(IL)-4在CD4和CD8 T细胞中的产生频率和强度。通过用纯化的蛋白质衍生物(PPD)和植物血凝素(PHA)刺激来评估T细胞功能。尽管数量减少,但患者T细胞中IFN-γ/ IL-4的表达明显高于健康供体。与健康供体相比,已治疗患者中大多数信号分子的强度相对未受影响,但低于未治疗的惰性患者。但是,表达每种信号分子的T细胞总数在患者中减少了,在氟达拉滨和阿仑单抗治疗的患者之间没有差异。在治疗的患者中,对PHA而非TPD的T细胞反应降低。结果表明,尽管在用氟达拉滨和阿仑单抗治疗后,长期而言,尽管信号分子发生了某些变化并且T细胞数量有所减少,但总体T细胞功能仍可以得到较好的保留。
  • 【在体内免疫复合物摄取后,树突状细胞而非巨噬细胞或B细胞激活主要的组织相容性复合物II类限制性CD4 T细胞。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2567.2006.02464.x 复制DOI
    作者列表:de Jong JM,Schuurhuis DH,Ioan-Facsinay A,Welling MM,Camps MG,van der Voort EI,Huizinga TW,Ossendorp F,Verbeek JS,Toes RE
    BACKGROUND & AIMS: :Professional antigen-presenting cells (APC) are able to process and present exogenous antigen leading to the activation of T cells. Antigen-immunoglobulin (Ig)G complexes (IC) are much more efficiently processed and presented than soluble antigen. Dendritic cells (DC) are known for their ability to take up and process immune complex (IC) via FcgammaR, and they have been shown to play a crucial role in IC-processing onto major histocompatibility complex (MHC) class I as they contain a specialized cross-presenting transport system required for MHC class I antigen-processing. However, the MHC class II-antigen-processing pathway is distinct. Therefore various other professional APC, like macrophages and B cells, all displaying FcgammaR, are thought to present IC-delivered antigen in MHC class II. Nonetheless, the relative contribution of these APC in IC-facilitated antigen-presentation for MHC class II in vivo is not known. Here we show that, in mice, both macrophages and DC, but not B cells, efficiently capture IC. However, only DC, but not macrophages, efficiently activate antigen-specific MHC class II restricted CD4(+) T cells. These results indicate that mainly DC and not other professional APC, despite expressing FcgammaR and MHC class II, contribute significantly to IC-facilitated T cell activation in vivo under steady-state conditions.
    背景与目标: :专业抗原呈递细胞(APC)能够处理并呈递导致T细胞活化的外源性抗原。抗原-免疫球蛋白(Ig)G复合物(IC)比可溶性抗原的加工和呈递效率更高。树突状细胞(DC)以其通过FcgR吸收并处理免疫复合物(IC)的能力而闻名,并且由于它们包含I型树突状细胞(DC),它们在IC处理I类主要组织相容性复合物(MHC)中起着至关重要的作用。 MHC I类抗原加工所需的专业交叉展示转运系统。但是,MHC II类抗原加工途径是不同的。因此,所有其他均显示FcγR的其他专业APC(如巨噬细胞和B细胞)被认为在II类MHC中呈递IC传递的抗原。然而,尚不清楚这些APC在体内II型MHC的IC促进的抗原呈递中的相对贡献。在这里,我们表明,在小鼠中,巨噬细胞和DC都有效捕获了IC,而B细胞却没有。但是,只有DC,而不是巨噬细胞,可以有效地激活II型MHC限制性抗原特异性CD4()T细胞。这些结果表明,尽管表达FcgammaR和II类MHC,主要还是DC,而不是其他专业APC,在稳态条件下在体内促进了IC促进的T细胞活化。

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