急性早幼粒细胞白血病全反式维甲酸治疗时IL—8及其受体表达 …

目的：探讨白细胞介素８（ＩＬ－８）及其Ａ型受体（ＩＬ－８ＲＡ）的表达在全反式维甲酸（ＡＴＲＡ）诱导治疗急性早幼粒细胞白血病（ＡＰＬ）中的临床意义。方法：动态检测ＡＰＬ患者１８例ＡＴＲＡ治疗中血浆ＩＬ－８水平（ＥＬＩＳＡ法）取３例骨髓单个核细胞（ＭＮＣ）加ＡＴＲＡ（１０＾－６ｍｍｏｌ／Ｌ）体外诱导，流式细胞仪动态检测ＭＮＣ膜Ｌ－８ＲＡ的表达。结果：ＭＮＣ加入ＡＴＲＡ诱导７２小时，上清ＩＬ－８水平明显     

维甲酸、砷剂及柔红霉素对NB4细胞组织因子表达的影响

目的　探讨全反式维甲酸（ Ａ Ｔ Ｒ Ａ） 、三氧化二砷（ Ａｓ２ Ｏ３） 及柔红霉素（ Ｄ Ｎ Ｒ） 对急性早幼粒细胞白血病（ Ａ Ｐ Ｌ） 细胞株 Ｎ Ｂ４ 细胞组织因子（ Ｔ Ｆ） 表达的影响。方法　用复钙时间检测 Ｎ Ｂ４ 细胞的促凝活性（ Ｐ Ｃ Ａ） ;用 Ｅ Ｌ Ｉ Ｓ Ａ 方法检测其 Ｔ Ｆ 抗原;用逆转录聚合酶链反应（ Ｒ Ｔ Ｐ Ｃ Ｒ） 检测 Ｔ Ｆｍ Ｒ Ｎ Ａ的转录水平。结果　 Ａ Ｔ Ｒ Ａ 和 Ａｓ２ Ｏ３ 均呈时间依赖的方式下调 Ｎ Ｂ４ 细胞的 Ｐ Ｃ Ａ、 Ｔ Ｆ 抗原水平以及 Ｔ Ｆ ｍ Ｒ Ｎ Ａ的转录;而 Ｄ Ｎ Ｒ 处理 Ｎ Ｂ４ 细胞的 Ｐ Ｃ Ａ及 Ｔ Ｆ 抗原在早期上调,至２４ ～４８ 小时达到最大值。对 Ｐ Ｃ Ｒ 产物测序,发现 Ａ Ｐ Ｌ 细胞 Ｔ Ｆ 第５ 个外显子缺失的转录本。结论　 Ａ Ｔ Ｒ Ａ 和 Ａｓ２ Ｏ３ 均可下调 Ａ Ｐ Ｌ 细胞 Ｔ Ｆ的表达并降低其 Ｐ Ｃ Ａ,改善 Ａ Ｐ Ｌ患者的弥散性血管内凝血（ Ｄ Ｉ Ｃ） 出血症状; Ａｓ２ Ｏ３ 和 Ｄ Ｎ Ｒ 对 Ａ Ｐ Ｌ凝血障碍不同效应的作用机制至少部分与药物对 Ａ Ｐ Ｌ细胞 Ｔ Ｆ 表达和 Ｐ Ｃ Ａ 的不同调节作用有关。     

小剂量亚硒酸钠和全反式维甲酸联合使用诱导NB4细胞的凋亡及分化

目的 研究小剂量亚硒酸钠（2－5μmol/L）与全反式维甲酸（ATRA）联合使用对人急性早幼粒细胞白血病细胞株NB4凋亡及分化的影响。方法 采用膜联蛋白V（Annexin-V)荧光标记试剂盒检测细胞的磷脂酰丝氨酸（PS）外翻率和DNA片段化的琼脂糖凝胶电泳检测细胞凋亡，通过流式细胞术检测粒系分化细胞表面特异抗原CD11b表达，NBT还原实验检测细胞分化。结果 阴性对照组细胞术检测粒系分化细胞表达特异抗原CD11b表达，NBT还原实验检测细胞分化。结果 阴性对照组细胞PS外翻率为1．2％，5μmol/L亚硒酸钠处理NB4细胞48h后PS外翻率为0.8%,0.1μmol/L ATRA诱导48h后PS外翻率为2．0％，与对照组相比，差异均无显著性,而两者联合作用NB4细胞24，36，48h后的PS外翻率分别达到18.3%,25.9%,50.0%,DNA电泳呈典型的梯形带。小剂量（2μmol/L）亚硒酸钠没有诱导NB4细胞分化的能力，但其与0．1μmol/L的ATRA联合使用同单独使用0．1μmol/L的ATRA钠没有诱导NB4细胞分化的能力，但其与0．1μmol/L的ATRA联合使用单独使用0．1μmol/L的ARTA相比，CD11b表达阳性细胞率进一步增加，NBT还原能力也进一步增强。结论 小剂量的亚硒酸钠与ATRA联合使用可诱导NB4细胞发生凋亡及分化。     

全反式维甲酸诱导APL细胞分化过程中钙信号途径基因表达水平的变化

为研究钙信号途径在髓系分化中的作用,采用基因芯片技术检测了钙信号途径相关基因在全反式维甲酸(ATRA)诱导急性早幼粒细胞性白血病(APL)细胞株NB4细胞分化过程中的表达情况,并运用实时定量RT-PCR验证基因芯片部分结果,同时检测这些基因在ATRA和8-CPT-cAMP单独和联合作用于NB4-R1细胞和ATRA诱导APL初诊患者原代细胞分化时的表达情况。结果发现:在ATRA诱导NB4细胞分化过程中,许多能直接调节胞内钙离子浓度的基因发生了变化,同时发现许多钙信号途径下游的效应分子的表达上调,并得到实时定量RT-PCR验证。这些基因在ATRA和8-CPT-cAMP单独作用于NB4-R1细胞时变化不大,而在ATRA和8-CPT-cAMP联合作用于NB4-R1细胞分化时与ATRA诱导NB4细胞分化时的表达变化相似。另外,以上基因在ATRA诱导APL初诊患者原代细胞分化的变化情况与诱导NB4细胞分化时相似。结论:钙信号途径可能参与了ATRA诱导的APL细胞分化。     

Perfluorocarbon blocks tumor necrosis factor-alpha-induced interleukin-8 release from alveolar epithelial cells in vitro

OBJECTIVE: To determine whether tumor necrosis factor (TNF)-alpha-induced interleukin (IL)-8 production by pulmonary alveolar epithelial cells is blocked by perfluorocarbon (PFC). DESIGN: Controlled, laboratory investigation of IL-8 production by pulmonary alveolar epithelial cells after exposure to PFC in vitro. SETTING: University research laboratory. SUBJECT: The human alveolar epithelial cell line with pulmonary type II (A549) cell properties. INTERVENTIONS: The A549 cells on a polycarbonate porous filter were stimulated either on the apical or the basolateral side with TNF-alpha. To determine TNF-alpha-induced IL-8 production, IL-8 was measured by using a human IL-8 kit in both control and experimental groups. MEASUREMENTS AND MAIN RESULTS: TNF-alpha stimulation induced a large increase in IL-8. When PFC was added to the medium immediately after TNF-alpha stimulation, PFC separated the medium from the cells and IL-8 production was markedly reduced (TNF-alpha alone, 8342+/-470 pg vs. TNF-alpha followed by PFC, 417+/-88 pg, p < .05). Preincubation of A549 cells with PFC for 24 hrs before stimulation with TNF-alpha followed by removal of PFC did not affect IL-8 production (8834+/-204 vs. 8342+/-470 pg; p = NS). When added to the lower chamber, TNF-alpha also induced IL-8 production unaffected by the addition of PFC to the upper chamber. The decrease in TNF-alpha-induced IL-8 production depended on the time of PFC administration after the initiation of TNF-alpha stimulation. The earlier PFC was added, the more pronounced the diminution was in IL-8. CONCLUSIONS: PFC appears to function as a physical barrier, thus reducing cytokines produced by alveolar epithelial cells in vitro. This mechanism may partially explain the decreased inflammatory response observed during liquid ventilation in models of acute lung injury.     

全反式维甲酸和柔红霉素对NB4和HL-60细胞株VEGF表达及分泌的影响

目的　探讨在全反式维甲酸 (ATRA)和柔红霉素 (DNR)的分别作用下 ,白血病细胞株NB4和HL 6 0VEGFmRNA表达及VEGF蛋白分泌的变化。方法　应用RT PCR法和ELISA方法研究ATRA和DNR分别对NB4和HL 6 0细胞VEGFmRNA表达及VEGF蛋白分泌的影响。结果　NB4和HL 6 0细胞中均有VEGFmRNA的表达和VEGF蛋白的分泌。ATRA(10 - 5～ 10 - 8mol L)及DNR(0 .0 1～2 .0 0 μmol L)在体外能分别下调NB4及HL 6 0细胞VEGFmRNA的表达和VEGF蛋白的分泌 ,并呈时间(3～ 72h)和剂量依赖性 (r值均为 - 1.0 0 ,P值均 <0 .0 1)。结论　这两种化疗药物除了可以诱导白血病细胞分化或抑制白血病细胞生长外 ,还可以通过抑制促血管新生 ,使新生血管减少 ,以发挥抗白血病的效应。     

Interleukin-8 gene expression by a pulmonary epithelial cell line. A model for cytokine networks in the lung.

Cellular constituents of the alveolar-capillary wall may be key participants in the recruitment of polymorphonuclear leukocytes to the lung through the generation of the novel neutrophil chemotactic peptide interleukin-8 (IL-8). This interaction appears to occur via the ability of human alveolar macrophage (AM)-derived monokines, tumor necrosis factor (TNF), and interleukin-1 (IL-1) to induce gene expression of IL-8 from pulmonary type II-like epithelial cells (A549). Northern blot analysis demonstrated that steady-state IL-8 mRNA expression, by either TNF- or IL-1 beta-treated A549 cells, occurred in both a dose- and time-dependent fashion. Similarly, extracellular antigenic IL-8, as assessed by specific ELISA, was expressed from TNF- or IL-1 beta-stimulated epithelial cells in a time-dependent fashion with maximal IL-8 antigen detected at 24 h poststimulation. Immunohistochemical staining utilizing rabbit anti-human IL-8 antibody identified immunoreactive, cell-associated IL-8 antigen as early as 8 h post-TNF or IL-1 beta stimulation. A549-generated neutrophil chemotactic bioactivity paralleled IL-8 steady-state mRNA levels. Signal specificity was demonstrated in this system as IL-8 mRNA or protein expression by lipopolysaccharide (LPS)-treated A549 cells was not different from unstimulated cells. Although LPS did not serve as a direct stimulus for the production of IL-8 by type II-like epithelial cells, the condition media from LPS-challenged AM induced a significant expression of IL-8 mRNA by the A549 cells. 24-h conditioned media from LPS-treated cells was as potent as either IL-1 beta or TNF in generating steady-state IL-8 mRNA by A549 cells. Preincubation of LPS-treated AM-conditioned media with anti-human TNF or IL-1 beta neutralizing antibodies resulted in significant abrogation of IL-8 gene expression by A549 pulmonary epithelial cells. These findings demonstrate potential cell-to-cell communication circuits that may be important between AMs and pulmonary epithelial cells during the recruitment phase of acute lung inflammation.     

Targeting expression of the leukemogenic PML-RARα fusion protein by lentiviral vector-mediated small interfering RNA results in leukemic cell differentiation and apoptosis

Acute promyelocytic leukemia (APL) results from a chromosomal translocation that gives rise to the leukemogenic fusion protein PML-RARα (promyelocytic leukemia-retinoic acid α receptor). Differentiation of leukemic cells and complete remission of APL are achieved by treatment of patients with pharmacological doses of all-trans retinoic acid (ATRA), making APL a model disease for differentiation therapy. However, because patients are resistant to further treatment with ATRA on relapse, it is necessary to develop alternative treatment strategies to specifically target APL. We therefore sought to develop a treatment strategy based on lentiviral vector-mediated delivery of small interfering RNA (siRNA) that specifically targets the breakpoint region of PML-RARα. Unlike treatment with ATRA, which resulted in differentiation of leukemic NB4 cells, delivery of siRNA targeting PML-RARα into NB4 cells resulted in both differentiation and apoptosis, consistent with the specific knockdown of PML-RARα. Intraperitoneal injection of NB4 cells transduced with lentiviral vectors delivering PML-RARα-specific siRNA but not control siRNA prevented development of disease in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Taken together, these results indicate that development of PML-RARα-specific siRNA may represent a promising treatment strategy for ATRA-resistant APL.     

乌苯美司增强全反式维甲酸诱导急性早幼粒细胞白血病细胞分化的体外研究

目的探讨氨肽酶N抑制剂乌苯美司（ubenimex）对全反式维甲酸（ATRA）诱导人急性早幼粒细胞白血病（APL）细胞分化的影响及可能机制。方法采用流式细胞术检测细胞表面分化抗原CD11b，四氮唑蓝（NBT）还原实验检测细胞分化；Western blot法检测细胞c—Myc、ERK1／2及P—ERK1/2 、p38MAPK及p—p38MAPK蛋白表达。结果ubenimex单独应用对NB4细胞的NBT还原能力及CD11b表达无明显影响，但ubenimex能增强ATRA诱导NB4细胞的NBT还原能力及CD11b的表达。100μg／mlubenimex能增强10nmol／LATRA诱导原代APL细胞的NBT还原能力。100μg／mlubenimex增强10nmol／LATRA下调NB4细胞c—Myc蛋白的表达；抑制10nmol／LATRA引起的NB4细胞的p38MAPK磷酸化。结论ubenimex能够增强ATRA对APL细胞的诱导分化作用，可能与抑制p38MAPK的磷酸化及对原癌基因c—Myc表达的调控有关。     

全反式维甲酸诱导急性早幼粒细胞白血病细胞分化中分化抑制因子1表达水平的变化

目的 探讨分化抑制因子1(ID1)在全反式维甲酸(ATRA)诱导急性早幼粒细胞白血病(APL)细胞分化中的作用.方法 运用基因芯片、放线菌酮抑制试验、实时定量RT-PCR和Western blot.方法 检测ID1存ATRA诱导的APL细胞系及原代APL细胞分化过程中表达情况.结果 在ATRA污导的NB4细胞和APL初诊患者原代细胞分化过程巾ID1基因的表达上调,ATRA诱导NB4细胞2hID1表达达高峰,其相对表达水平与对照相比升高359.4±48.7倍;ATRA处理APL患者骨髓细胞ID1表达水平2 h达高峰,其中1例患者晕复3次检测的.结果 为对照的(311.1±48.7)倍.而且ID1基因的上调不需要其他蛋白的合成.而在ATRA处理ATRA耐药细胞系NB4-R2细胞未见ID1的表达发生明显变化.结论 ID1基因可能作为ATRA的靶基因参与了ATRA诱导的粒系分化.     

Alveolar type II epithelial cells produce interleukin-6 in vitro and in vivo. Regulation by alveolar macrophage secretory products.

The aims of this study were (a) to determine if rat alveolar type II (ATII) cells and human pulmonary epithelial-derived cells (A549 cell line) could generate IL-6 in vitro, (b) to characterize the cytokine regulation of IL-6 gene and protein expression in these cells, and (c) to detect the in vivo expression of immunoreactive IL-6 by human ATII cells. Rat ATII cells in primary culture secreted bioactive IL-6 and immunostained with an anti-IL-6 antiserum. Spontaneous IL-6 secretion by rat ATII cells amounted to 5,690 +/- 770 pg/ml/10(6) cells (n = 12) and was fivefold higher than spontaneous rat alveolar macrophages IL-6 secretion (1,052 +/- 286 pg/ml/10(6) cells, n = 8, P = 0.001). Rat alveolar macrophage conditioned media (CM) increased IL-6 secretion by rat ATII cells through the effect of IL-1 and TNF. IL-6 gene expression and IL-6 secretion by A549 cells was induced by IL-1 beta, TNF alpha, and by human alveolar macrophages and THP1 cells CM. Induction was abolished when CM were preincubated with anti-IL-1 beta and anti-TNF alpha antibody. The combination of IFN gamma and LPS induced the expression of IL-6 mRNA by A549 cells whereas LPS alone had no effect. Immunohistochemical staining evidenced the expression of immunoreactive IL-6 by hyperplastic ATII cells in fibrotic human lung, a condition in which alveolar macrophages are known to be activated. ATII cells in normal human lung did not express immunoreactive IL-6. Our findings demonstrate that ATII cells may be an important source of IL-6 in the alveolar space thereby participating to the regulation of the intra-alveolar immune response.     

苦参碱对急性早幼粒细胞白血病细胞维甲酸耐药的逆转作用研究

目的 探讨苦参碱逆转急性早幼粒细胞白血病(APL)全反式维甲酸(ATRA)耐药的作用及可能的机制.方法 以ATRA敏感的APL细胞系NB4及其ATRA耐药株NB4-R1、NIM-R2作为研究对象.用MTT法明确苦参碱低毒性剂量,进一步计算ATRA联合100μmoL/L苦参碱作用前后细胞ATRA IC50值,明确苦参碱的逆转耐药倍数;用NBT还原实验分析不同浓度(10、8、6、4、2、1、mmol/L,100、10、1μmol/L)苦参碱联用1μmol/L ATRA对耐药细胞分化能力的影响,并观察细胞形态变化;Annexin V/PI染色流式细胞术检测不同浓度苦参碱联用1 μmol/L ATRA作用下细胞凋亡率.结果 ①苦参碱对NB4、NB4-R1、NB4-R2细胞的增殖抑制作用随浓度增加而增强,IC50值分别为(0.661±0.035)、(0.673±0.132)、(0.329±0.020)mmol/L;②联用100 μmol/L苦参碱能显著逆转NB4-R1细胞的耐药性(逆转耐药倍数为4.96±1.15),但不能增强NB4-R2细胞对ATRA的敏感性,甚至增强其耐药性(逆转耐药倍数为0.66±0.17);③苦参碱与1 μmol/L ATRA联用时,NB4、NB4-R1细胞的分化能力随苦参碱作用浓度的增大而增强,且在苦参碱为100 μmol/L时达到峰值(P<0.05),但对NB4-R2细胞无明显影响;④1 μmol/L ATRA联合苦参碱能显著提高NB4、NB4-R1细胞凋亡率(P<0.05和P<0.01),但对NB4-R2细胞同样无明显作用.结论 苦参碱能有效逆转NB4-R1细胞的ATRA耐药,可能与其协同ATRA诱导分化及促进细胞凋亡有关.苦参碱与ATRA联用非但不能缓解NB4-R2细胞的ATRA耐药,甚至可能加重耐药、阻断耐药细胞的凋亡过程.     

Phosphatidylserine exposure and procoagulant activity in acute promyelocytic leukemia

Summary. Background: Acute promyelocytic leukemia (APL) frequently causes disseminated intravascular coagulation that can worsen with cytotoxic chemotherapy but improve with the therapeutic differentiating agents, all trans retinoic acid (ATRA) and arsenic trioxide (As₂O₃). APL cells display tissue factor but the relationship of tissue factor and other procoagulant activity to phosphatidylserine (PS) exposure is largely unknown. Methods: Lactadherin, a milk protein with stereospecific binding to phosphatidyl‐L‐serine, was used as a probe for PS exposure on an immortalized APL cell line (NB4) and on the cells of eight patients with APL. PS exposure was evaluated with flow cytometry, confocal microscopy, coagulation assays, and purified prothrombinase and factor (F) Xase assays. Results: Plasma procoagulant activity of NB4 and APL cells increased approximately 15‐fold after exposure to etoposide or daunorubicin and decreased 80% after treatment with ATRA or As₂O₃. Procoagulant activity corresponded to exposed PS on viable APL cells. PS exposure decreased after treatment with ATRA or As₂O₃ and increased after treatment with daunorubicin or etoposide. Excess lactadherin inhibited 80–85% of intrinsic FXase, FVIIa‐tissue factor and prothrombinase activities on both NB4 cells and APL cells. Confocal microscopy identified membrane patches that stained with lactadherin, but not annexin V, demonstrating focal, low‐level PS exposure. Conclusions: PS is exposed on viable APL cells and is necessary for approximately 80% of procoagulant activity.     

腺苷酸环化酶的活化影响NB4细胞对全反式维甲酸的敏感性

目的　探讨急性早幼粒细胞白血病 (APL)细胞对全反式维甲酸 (ATRA)耐药的分子机制。方法　以ATRA敏感及耐药的APL细胞株NB4和NB4 R1为模型 ,观察细胞形态、表面分化抗原以及对四氮唑蓝还原能力的改变 ,分别研究腺苷酸环化酶 (AC)和磷酸二酯酶 (PDE)的特异激活剂毛喉素、拮抗剂 9 (四氢 2 呋喃基 ) 9H 嘌呤 6 氨 (SQ2 2 5 36 )对ATRA诱导分化作用的影响。结果　AC的拮抗剂SQ2 2 5 36能显著抑制ATRA对NB4细胞的诱导分化作用 ,ATRA SQ2 2 5 36组与ATRA组比较 ,CD11b阳性率由 (95 .9± 2 .5 ) %降至 (6 0 .3± 7.1) % ,NBT还原实验吸光度 (A) 540 值由 0 .5 85±0 .0 92降至 0 .170± 0 .0 2 8,差异有显著性 (P <0 .0 5 )。而AC的激活剂毛喉素则可以克服NB4 R1细胞对ATRA的耐药 ,ATRA 毛喉素组与ATRA组比较 ,CD11b阳性率由 (34.3± 5 .3) %升高至 (94 .6±2 .4 ) % ,NBT还原实验A540 值由 0 .110± 0 .0 2 8升高至 0 .395± 0 .0 4 9,差异有显著性 (P <0 .0 5 )。PDE的特异激活剂钙调蛋白以及拮抗剂 3 异丁基 1 甲基黄嘌呤 (IBMX)对ATRA的作用基本没有影响。结论　AC能否正常激活也许是APL对ATRA产生耐药的重要原因之一。     

姜黄素联合全反式维甲酸诱导耐药的急性早幼粒细胞白血病细胞分化的实验研究

本研究旨在探讨姜黄素联合全反式维甲酸(ATRA)对耐药的急性早幼粒细胞白血病细胞分化的影响及其分子机制。以耐药的NB4-R1细胞为实验对象,对细胞进行计数和细胞形态学观察,应用流式细胞术(FCM)检测姜黄素单用或联合ATRA对NB4-R1细胞增殖、分化的影响;用Western blot检测AKT磷酸化在细胞分化中的变化。结果显示,全反式维甲酸对NB4-R1细胞增殖无影响,但可增强姜黄素对NB4-R1生长的抑制作用。单用姜黄素或全反式维甲酸对细胞分化无影响,姜黄素联合全反式维甲酸可明显诱导细胞CD11b表达,细胞在形态上呈明显分化特征。全反式维甲酸可在短时间内促进NB4细胞AKT第473苏氨酸磷酸化,而对NB4-R1细胞中的AKT磷酸化影响不大。姜黄素可以促进NB4-R1细胞AKT磷酸化,而联合全反式维甲酸可进一步增强AKT磷酸化。结论:PI3K/AKT通路失活可能是导致APL细胞耐药的因素之一,而姜黄素通过活化PI3K/AKT信号通路逆转APL耐药,促进NB4-R1细胞分化。     

APN/CD13对乌苯美司增强全反式维甲酸诱导急性早幼粒白血病细胞株NB4细胞分化的影响

本研究探讨细胞表面APN/CD13在乌苯美司(bestatin)增强全反式维甲酸(ATRA)诱导急性早幼粒细胞白血病(APL)细胞株NB4细胞分化过程中的作用.采用四氮唑蓝还原实验检测细胞分化;Western blot检测细胞P38MAPK及p-P38MAPK蛋白表达.结果显示:APN/CD13中和抗体WM-15能够完全阻断乌苯美司对ATRA诱导分化作用的增强效应.WM-15能够部分阻断乌苯美司抑制NB4细胞P38 MAPK磷酸化的作用.100μg/ml乌苯美司呈时间依赖性抑制APL细胞株NB4细胞及MR2细胞的P38MAPK磷酸化水平,l00 μg/ml乌苯美司对CD13表达低下的K562细胞的P38 MAPK磷酸化水平无明显影响.100μg/ml乌苯美司不能恢复MR2细胞及难治复发患者原代APL细胞对ATRA的敏感性.结论:氨肽酶N/CD13抑制剂乌苯美司可能通过细胞表面APN/CD13分子的介导抑制NB4细胞P38 MAPK的磷酸化,从而增强ATRA诱导NB4细胞分化的作用.     

急性早幼粒白血病细胞CD59表达缺失

CD59是糖基磷脂酰肌醇锚定蛋白,通过抑制膜攻击复合物保护细胞免受补体介导的溶细胞作用。本研究探讨急性早幼粒细胞白血病(APL)细胞CD59表达情况。应用流式细胞术检测19例急性早幼粒白血病细胞CD59的表达及NB4细胞经全反式维甲酸(ATRA)处理前后CD59的表达。用PCR方法扩增白血病患者和NB4细胞的pig-A基因编码序列并进行测序。结果表明,19例初治APL患者中12例CD59膜表达缺失,高于其他非APL细胞(40例non-APL中14例缺失,p=0.042)。对6例治疗前CD59表达缺失APL患者CR后再次检测CD59的表达,6例患者CD59的表达在CR后均恢复正常,这提示CD59的表达缺失只发生在早幼粒白血病细胞上。检测发现APL细胞系NB4的CD59表达也缺失,NB4细胞经ATRA处理后CD59的表达并没有随着细胞分化而出现变化。对NB4细胞和1例CD59表达缺失APL患者的pig-A基因编码序列测序显示,pig-A基因编码序列没有突变,因此APL的CD59表达缺失并不是由于pig-A基因的突变造成的。结论:APL细胞较多地有CD59表达缺失。     

Pneumocystis carinii major surface glycoprotein induces interleukin-8 and monocyte chemoattractant protein-1 release from a human alveolar epithelial cell line

BACKGROUND: The major surface glycoprotein (MSG) is an abundant, immunogenic glycoprotein located on the surface of Pneumocystis carinii. Little is known about the proinflammatory effects of MSG. DESIGN: We have investigated the effect of human MSG on the secretion of the chemokines interleukin 8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) from an alveolar epithelial cell line (A549). RESULTS: Incubation of A549 cells with MSG in concentrations from 0.4 to 10 microg mL-1 for 24 h caused dose-dependent increases in IL-8 release (3.4-fold above control, P < 0.01). Time course experiments showed increases in IL-8 release at 4 h, 8 h and 24 h compared with control cultures (all P < 0.01). There was a minor (13%) dose- and time-related increase in MCP-1 release at 24 h (P = 0.02). Co-incubation of MSG with mannan or beta-glucan decreased IL-8 release by 48% and 42% respectively, suggesting that MSG stimulates A549 cells in part through carbohydrate moieties. Dexamethasone significantly inhibited MSG-induced IL-8 release in concentrations of 10-6-10-8 mol L-1 compared with control experiments (P < 0.01). Ribonuclease protection assays for steady-state IL-8 mRNA showed that increases in response to MSG stimulation occurred by 4 h and persisted throughout 8 h of stimulation. CONCLUSION: These findings suggest that MSG can alter alveolar epithelial cytokine release and may be capable of modulating the local inflammatory response in this manner.     

全反式维甲酸与三氧化二砷对NB4细胞CD44v6表达的调节

黏附分子CD44v6与急性髓系白血病(AML)疾病进展密切相关。本研究探讨全反式维甲酸(ATRA)及三氧化二砷(As2O3)对急性早幼粒细胞白血病细胞系NB4细胞CD44v6及其相关的PI3K/Akt信号通路的影响。应用显微镜观察检查和流式细胞术检测NB4细胞的分化;AnnexinⅤ-FITC/PI双染色流式细胞术检测NB4细胞凋亡;实时RT-PCR检测NB4细胞CD44v6 mRNA的表达;Western blot检测NB4细胞CD44v6蛋白的表达及PI3K/Akt信号通路的变化。结果显示:在ATRA诱导NB4细胞分化过程中,CD44v6的转录明显受抑制,但CD44v6蛋白表达无明显增减,PI3K/Akt信号通路被激活。在As2O3诱导NB4细胞凋亡过程中,CD44v6的转录水平及蛋白表达均明显下调,PI3K/Akt信号通路受抑。结论:ATRA与As2O3对NB4细胞CD44v6表达的影响不同。此研究结果为从干预白血病细胞和造血微环境相互关联角度进一步揭示ATRA和As2O3的作用机制奠定了实验基础。