Adherence betweenEntamoeba histolytica trophozoites and undifferentiated or DMSO-induced HL-60 cells

Differentiation of promyelocytic HL-60 cells along the pathway toward granulocytes using dimethylsulfoxide (DMSO) led to increased expression of the adhesion molecules CD11b (Mac-1), CD11c (p150,95), and CD35 (CR1). Undifferentiated and differentiated HL-60 cells adhered similarly toEntamoeba histolytica trophozoites, and monoclonal antibodies against adhesion molecules CD11b and CD11c did not inhibit adherence. We therefore suggest that CD11b and CD11c are not involved in the adherence between polymorphonuclear granulocytes andE. histolytica trophozoites.     

Infection of undifferentiated and differentiated promyelocytic cells (HL-60) with varicella-zoster virus

HL-60 cells can be induced to differentiate into macrophage-like cells by treatment with 12-O-tetra-decanoylphorbol-13-acetate (TPA). The relationship between virus replication and cell differentiation was investigated using HL-60 cells that had been induced to differentiate by TPA (dHL-60 cells) and undifferentiated cells (udHL-60 cells). On infection of these cells with cell-free varicella-zoster virus (VZV), virus antigens were detected in dHL-60 cells but not in udHL-60 cells, and the percentage of antigen-positive dHL-60 cells increased during incubation. Similar results were obtained by infectious center assay, and the percentage of antigen-positive cells correlated with the stage of cell differentiation. No significant difference was found in the binding of VZV to dHL-60 cells and udHL-60 cells. Furthermore, trypsin treatment after adsorption suggested that VZV penetrated into udHL-60 cells. These findings indicate that VZV may be able to replicate in mature monocytes but may be harbored in immature monocytes in vivo.     

HL-60细胞及其耐药细胞株HL-60/ADM超弱发光的检测

目的:探讨人急性早幼粒白血病细胞系(HL-60)和其耐药株抗阿霉素人急性早幼粒白血病细胞系(HL-60/ADM)的超弱发光与耐药性的关系。方法:应用MTT比色法、流式细胞术、细胞生长曲线和免疫组化染色法,检测HL-60细胞、HL-60/ADM细胞对阿霉素(ADM)的敏感性、细胞周期变化及P-糖蛋白(P-gp170)的表达。用IFFM-D型流动式化学发光仪检测HL-60细胞及HL-60/ADM细胞的超弱发光强度。结果:HL-60/ADM细胞对ADM的敏感性明显低于亲本HL-60细胞;HL-60/ADM细胞中G0/G1期的细胞为44·80%±1·97%,G2/M期的细胞为9·90%±0·27%,较其亲本细胞增多,S期的细胞为45·30%±1·93%,较其亲本细胞减少(P<0·05);HL-60/ADM细胞倍增时间是HL-60细胞的1·8倍,P-gp170的表达呈阳性,HL-60细胞呈阴性。在1×10-4mol/L鲁米诺及3mL/L双氧水条件下,密度分别为8×107/L、1×108/L、1·26×108/L及2·73×108/L的HL-60/ADM细胞超弱发光强度低于HL-60细胞(P<0·05)。结论:HL-60/ADM细胞对ADM的敏感性降低,细胞生长延缓,P-gp170表达呈阳性等均提示HL-60/ADM细胞出现了耐药性;且随着HL-60/ADM细胞耐药性的产生其超弱发光强度较其亲本细胞HL-60降低,提示细胞超弱发光强度明显降低可作为细胞耐药性产生的一项指标。     

Mechanism of the eosinophilic differentiation of HL-60 clone 15 cells induced by n-butyrate

n-Butyrate is one of the most powerful chemical inducers of the differentiation of human eosinophilic leukemia HL-60 clone 15 cells into mature eosinophils. We have recently reported that the mechanism by which HL-60 clone 15 cells differentiate into eosinophils by n-butyrate is that n-butyrate continuously inhibits histone deacetylase activity as a histone deacetylase inhibitor, resulting in continuous acetylation of histones. In this review, we discuss roles of histone acetyltransferase, histone deacetylase and histone deacetylase inhibitors in the differentiation of HL-60 clone 15 cells into eosinophils.     

Reconstitution of chemokine-induced actin polymerization in undifferentiated human leukemia cells (HL-60) by heterologous expression of interleukin-8 receptors

The chemokines interleukin-8 (IL-8) and GRO bind in neutrophils to the interleukin-8 receptor and (IL-8R and ) triggering reorganization of the actin cytoskeleton and activation of phospholipase C (PLC). Reconstitution of chemokine-induced activation of PLC indicated coupling of IL-8R and to pertussis toxin-insensitive or . To identify the signal transduction mechanisms of chemokine-induced actin response, undifferentiated human leukemia cells (HL-60 cells) constitutively expressing , and were chosen for reconstitution studies. Expression of recombinant receptors after transfection of the cells with the cDNA of IL-8R and was confirmed by binding studies with radiolabeled ligands. IL-8R bound IL-8 with high affinity (Kd1 nM) and GRO with low affinity (Kd 1 M), whereas IL-8R bound both IL-8 and GRO with high affinity (Kd1 nM). Flow cytometric actin measurements indicated that high affinity ligand-receptor interactions in both receptor transfectants displayed inducible responses. Pretreatment of transfectants with pertussis toxin caused ADP-ribosylation of G-proteins and blocked chemokine-induced polymerization, indicating involvement of or , but not in this response.accepted by M.J. Parnham     

The degranulation response in differentiated HL-60 cells

HL-60 cells differentiate into mature granulocytes in response to treatment with a variety of chemical agents. Such HL-60 cell derived granulocytes display many of the properties associated with their peripheral blood counterpart. In this study we have investigated the development of the degranulation response in dimethylsulfoxide (DMSO) or retinoic acid differentiated HL-60 cells over a six day period. The release of a number of enzymes in response to stimulation by a variety of agents was examined. Soluble aggregated IgG (SAIgG) stimulated the release primarily of elastase from HL-60 derived granulocytes with little or no release of other granule enzymes, in particular myeloperoxidase. This contrasted to what was seen when peripheral blood granulocytes were used. The lack of myeloperoxidase release was not due to the parallel release of enzyme inhibitors or failure of the stimulus to bind to the cells. Neither was it due to variations in the kinetics of enzyme release or the presence of myeloperoxidase and elastase in discrete sub-populations of HL-60 cells. When other stimuli such as fMet-Leu-Phe, A23187, or phorbol myristate acetate (PMA) were used a relatively normal degranulation response was seen. Thus, the degranulation response in granulocytes derived from HL-60 cells appears relatively normal when a range of commonly used stimuli are used but is impaired when aggregates of IgG are used.     

Factors influencing basophilic differentiation of HL-60 cells

Lineage-specific hematopoietins apparently act in concert with multipotent factors in an orderly sequence of growth and differentiation. We have used the human acute promyelocytic leukemia cell line HL-60 to examine basophilic differentiation, using radioenzymatic assay of histamine content as an end point. Recombinant human interleukin 1 (rhIL-1), rhIL-2, rhIL-4, and recombinant human alpha and gamma interferons did not stimulate basophilic differentiation either in the presence or absence of sodium butyrate, an important cofactor for induction of differentiation. In contrast, rhG-CSF (granulocyte colony-stimulating factor), rhGM (granulocyte-macrophage) CSF, rhIL-3, rhIL-5, nerve growth factor, conditioned medium (CM) from the hairy T cell leukemic line Mo, and nasal polyp epithelial CM stimulated significant increases in histamine content in HL-60 cells at day 5 in vitro. GM-CSF did not account for all of the basophilic differentiating activity in Mo-CM. The data suggest that a unique, lineage-specific, basophilic cell differentiation factor is produced by T cells and point to the possible diagnostic and therapeutic relevance of in situ hematopoietic mechanisms in human respiratory disease.     

Targeting myeloperoxidase to azurophilic granules in HL-60 cells

Myeloperoxidase (MPO) is a cationic protein and one of the major constituents of azurophilic granules in neutrophils. Here, we examined whether intracellular transport of MPO and serglycin, a chondroitin sulfate (CS)-bearing proteoglycan, is correlated. First, we examined binding of MPO to CS-Sepharose and measured an ionic interaction, which was disrupted by 200-400 mM NaCl. Next, HL-60 promyelocytes were activated with a phorbol ester, which induced an almost complete rerouting of serglycin from the granular to the secretory pathway, concomitant with a similar effect on MPO transport and secretion. We then used the membrane-permeable cross-linker dithiobis(succininmidylpropionate; DSP) after labeling HL-60 cells with [35S]methionine and [35S]cysteine for 19 h. Immunoprecipitation of MPO revealed its cross-linking to high molecular material having the appearance of a proteoglycan in sodium dodecyl sulfate-polyacrylamide gels. This assumption was confirmed by labeling HL-60 cells with [35S]sulfate for 10 min followed by DSP cross-linking and immunoprecipitation. From three granular enzymes immunoprecipitated, only the cationic MPO was cross-linked to [35S]sulfate-labeled serglycin in appreciable quantities, whereas cathepsin D or beta-N-acetylhexosaminidase was not. Thus, intracellular transport of MPO appears to be linked to that of serglycin. Extracts from high buoyant density organelles from human placenta containing MPO activity were subjected to CS-affinity chromatography. Proteins binding to CS were identified by mass spectrometry as MPO, lactoferrin, cathepsin G, and azurocidin/cationic antimicrobial protein of molecular weight 37 kDa, suggesting that serglycin may be a general transport vehicle for the cationic granular proteins of neutrophils.     

维生素K3对HL-60细胞凋亡的诱导作用

目的:观察维生素K₃(VK₃)对HL-60细胞凋亡的诱导作用。方法:通过形态学、DNA电泳、Annexin V标记法检测VK₃作用后HL-60细胞的凋亡发生情况。结果:2、5、10、20 μmol/L的VK₃作用于HL-60细胞48h后凋亡发生率分别为8.76%、9.7%、18.54%、75.4%;10 μmol/L的VK₃作用于HL-60细胞24、48、72、96 h后凋亡发生率分别为11.35%、18.54%、21.22%、37.54%。结论:VK₃能诱导HL-60细胞发生凋亡,并具有一定的量效和时效关系。     

茶多酚在体外诱导HL-60细胞的凋亡

目的：寻找新的肿瘤细胞凋亡诱导剂。方法：选用茶的主要活性成分茶多酚,采用噻唑蓝（ＭＴＴ）还原法,ＤＮＡ凝胶电泳以及透射电镜技术,在体外观察了茶多酚对人急性早幼粒白血病细胞（ＨＬ－６０）凋亡的影响。结果：被２５０ｍｇ／Ｌ茶多酚作用５ｈ后ＨＬ－６０细胞进行凝胶电泳呈现出典型的ＤＮＡ条带,透射电镜下看到凋亡小体,茶多酚对ＨＬ－６０细胞凋亡的诱导活性平行于它的细胞杀伤作用。结论：在体外培养条件下,茶多酚可诱导ＨＬ－６０细胞凋亡     

达努塞替对HL-60细胞抗肿瘤作用机制的研究

目的:探讨丝氨酸/苏氨酸激酶抑制剂达努塞替对人急性髓细胞白血病(AML)细胞株HL-60的细胞周期阻滞、自噬和凋亡的影响。方法:用MTT法检测达努塞替对HL-60细胞的生长抑制作用;用流式细胞术检测相同时间不同浓度药物组与同一浓度不同时间组的细胞周期、细胞凋亡及细胞自噬;用Western blot方法检测细胞周期相关蛋白CDK1/CDC2、CDK2、cyclin B1、P21Waf1/Cip1、P27Kip1和P53,凋亡相关蛋白Bcl-x L、Bcl-2、Bax、PUMA、cleaved caspase-3及cleaved caspase-9以及自噬相关蛋白p-PI3K、PTEN、p-Akt、p-m TOR、Beclin 1、LC3-I和LC3-II的水平。用共聚焦显微镜检测同时间不同浓度药物组细胞的自噬情况。结果:达努塞替能明显抑制HL-60细胞的活力,诱导细胞周期G2/M期阻滞,可以通过线粒体caspase-3途径诱导细胞凋亡,同时可以通过抑制PI3K/Akt/m TOR信号通路诱导细胞自噬。结论:达努塞替可通过抑制作为染色体伴侣蛋白且在有丝分裂中调控染色质复制与分离的极光激酶A/B有效抑制HL-60细胞生长,引起细胞周期阻滞、凋亡和自噬发生,可能是AML临床治疗具有前景的抗肿瘤靶点。     

Histamine-induced differentiation of eosinophilic subclone of HL-60 cells

Inflammation Research -     

Cryopreservation of differentiated HL-60 cells for pyrogen testing

All-trans retinoic-acid (ATRA) differentiated HL-60 cells can be used to detect pyrogens such as bacteria, bacterial components, yeasts and fungi. Differentiated HL-60 cells obtain neutrophil like characteristics and if stimulated the differentiated HL-60 cells produce reactive oxygen species in a dose dependent manner. Culturing and differentiation of cell lines are time consuming activities and require suitable facilities; cryopreservation of pre-differentiated cells could provide the basis for an easily distributable pyrogen testing kit. Cryopreservation of granulocytes has proven to be very complicated and neutrophils are especially difficult to cryopreserve, most likely due to their large degree of granulation. Here we present evidence that HL-60 cells can be differentiated with ATRA and subsequently cryopreserved. Upon thawing the cells retain their ROS producing capabilities and reactivity towards pyrogens. Further, the cells retain their ability to react dose dependently towards lipopolysaccharide (LPS), lipoteichoic acid (LTA) and zymosan. At pathophysiologically relevant concentrations of LPS, LTA and zymosan the cells retain full reactivity for at least two months when stored in liquid nitrogen. In conclusion, ATRA differentiated HL-60 cells are cryopreservable and retain reactivity upon thawing. It is therefore possible to produce an in-vitro in-house pyrogen test kit for medicines and related products.     

黄芩苷对HL-60白血病细胞的诱导分化作用

目的： 观察中药单体黄芩苷(baicalin) 对人髓系白血病（AML）细胞株HL-60细胞的诱导分化作用。方法: 应用细胞形态学方法、细胞克隆形成试验、流式细胞术分析和NBT还原实验检测黄芩苷诱导HL-60细胞分化的能力。结果: 黄芩苷可诱导HL-60细胞向成熟阶段分化，低浓度黄芩苷可显著抑制HL-60细胞克隆的形成；HL-60细胞经黄芩苷处理后CD11b表达显著增高，CD33表达显著降低；NBT还原实验示黄芩苷处理组的分化成熟细胞阳性率明显高于未加药组。结论: 黄芩苷具有诱导HL-60白血病细胞向成熟粒细胞分化的作用。     

冬凌草甲素对急性白血病HL-60细胞的增殖抑制作用及其作用机制

目的探讨冬凌草甲素对急性白血病HL-60细胞的增殖抑制作用及其作用机制。方法以不同浓度的冬凌草甲素作用于体外培养的HL-60细胞，MTr法检测细胞生长抑制率，应用流式细胞仪检测细胞凋亡情况，瑞氏染色法观察细胞凋亡时的形态学变化。应用PCR．ELISA及RT—PCR法检测细胞凋亡前后端粒酶活性及端粒酶hTERT mRNA表达水平的变化。结果冬凌草甲素可显著的抑制HL-60细胞的生长，诱导细胞发生凋亡，并呈现出明显的量-与时-效关系。冬凌草甲素作用48—60h后在瑞氏染色图片上可见核浓缩及核碎裂等典型的细胞凋亡特征，同时端粒酶hTERT mRNA的表达水平及端粒酶活性均明显降低。结论冬凌草甲素能抑制HL-60细胞的生长及诱导细胞发生凋亡：降低端粒酶hTERT mRNA的表达水平及端粒酶活性可能是其重要作用机制之一。     

Increased ROS generation in subsets of OGG1 knockout fibroblast cells

Oxoguanine DNA glycosylase (OGG1) is a major base excision repair protein responsible for excision of the mutagenic 8-oxoguanosine (8-oxoG) lesions from the genome. Despite OGG1's importance, the moderate phenotype of Ogg1-null (Ogg1(-/-)) mice is not well understood. This study addresses a mechanism by which Ogg1(-/-) cells limit accumulation of 8-oxoG in their genome. Our data reveal that a subset of Ogg1(-/-) cells shows higher ROS levels ((H)ROS cells), while approximately 85% of Ogg1(-/-) cells exhibit physiological levels of ROS ((L)ROS cells). Ogg1(-/-) cells were sorted based on their DCF fluorescence intensity to obtain (L)ROS and (H)ROS cell cultures. (L)ROS cultures proliferated at a rate comparable to Ogg1(+/+) and gradually accumulated cells exhibiting increased ROS and 8-oxoG levels. (L)ROS cells show a 2.8-fold increase in 8-oxoG level vs. (H)ROS cells (7-27-fold). Mitochondria of (H)ROS cells released more H(2)O(2) than (L)ROS and Ogg1(+/+) cells and were eliminated by apoptotic-like processes. These findings suggest that in the absence of OGG1, a surveillance system is activated that removes cells with extreme 8-oxoG levels from Ogg1(-/-) cultures. Whether similar mechanisms exists in tissues of Ogg1(-/-) mice is the focus of future investigations.     

Histamine-induced bi-directional differentiation of HL-60 cells towards neutrophils and eosinophils

HL-60 cells, treated under alkaline conditions (pH 7.6) or acidic conditions (pH 7.2) for 2 months, were stimulated with histamine for 7 days. From the morphological examination and cytochemical characterization, it became clear that one of the clones treated in acidic pH differentiated to neutrophils and the other clone treated in alkaline medium differentiated to eosinophils after histamine-stimulation. The growth curve reached a maximum 4 days after stimulation. By means ofin situ hybridization, it has been shown that the mRNA of major basic protein increased after histamine treatment only in the eosinophilic subclone, starting 4 days after stimulation. From the present study, it is suggested that when HL-60 cells were cultured under different pH conditions, commitment of lineages to the direction of either eosinophils or neutrophils takes place. Histamine may potently stimulate the further differentiation of both eosinophilic and neutrophilic clones.

     

AKT-mediated regulation of polarization in differentiated human neutrophil-like HL-60 cells

Objectives

Neutrophil polarization is critical for the inflammatory response. AKT is a serine/threonine protein kinase and has been implicated in cell migration. However, it is not completely clear whether AKT affects neutrophil polarization. In this study, we tested the hypothesis that AKT regulates the polarization of neutrophil-like differentiated HL-60 cells (dHL-60) in response to fMLP.

Methods

HL-60 cells were differentiated into dHL-60 by incubation in medium containing 1.3?% DMSO for up to 6?days. Polarization of dHL-60 cells and primary human neutrophils were measured by Zigmond chamber. Phospho-Akt was analyzed by immunofluorescence and Western blot analysis. F-actin polymerization was detected by Rhodamine-Phalloidine staining. Rac2 activation was evaluated using GST Pull-down assay.

Results

We found that changes in the rate of cell polarization were consistent with the changes in AKT phosphorylation levels during HL-60 cell differentiation in response to fMLP. Moreover, cell polarization and AKT phosphorylation were reduced in fMLP-stimulated dHL-60 cells pretreated with the PI3 kinase inhibitors or the AKT inhibitors, which was confirmed in the primary human neutrophils. The AKT inhibitors altered fMLP-induced F-actin polymerization. Rac2 GTPases was also decreased by the AKT inhibitors in fMLP-stimulated dHL-60 cells.

Conclusion

This study demonstrates that AKT activation plays a crucial role in dHL-60 cell polarization.