Anti-endothelial cell antibodies to the endothelial hybridoma cell line (EAhy926) in systemic lupus erythematosus patients with antiphospholipid antibodies

The endothelial hybridoma (EAhy926) cell line was employed to clarify whether antiphospholipid antibodies (aPA) [lupus anticoagulant (LA), antiprothrombin antibody (aPT) and/or anticardiolipin antibody (aCL)] and anti-endothelial cell antibodies (AECA) are identical, and establish whether β₂-glycoprotein I (β₂-GPI) is needed for reactivity of aPA to endothelial cells. Ig-G AECA was positive in 9/30 SLE patients with aPA (30.0%) and 10/22 SLE patients negative for aPA (45.5%). Ig-M AECA was positive in one SLE patient with aPA and one SLE patient without aPA. AECA-positivity was not significantly different among unfixed, TNF-stimulated and fixed EAhy926. The influence of β₂-GPI on the reactivity of serum to EAhy926 was minimal, and absorption experiments of serum with cardiolipin-liposome/β₂-GPI or phosphatidylserine-liposome/prothrombin gave little evidence of cross-reactivity of aPA and AECA. The results of our study suggest that aPA and AECA may have partially cross-reacted, but were different antibodies. However, further study is needed to clarify the clinico-pathological significance of AECA.     

Differentiation of a human eosinophilic leukemia cell line (EoL-1) by a human T-cell leukemia cell line (HIL-3)-derived factor.

Differentiation of a human eosinophilic leukemia cell line, EoL-1, induced by the culture supernatant of a human ATL cell line, HIL-3 (HIL-3 sup) was compared with differentiation induced by defined cytokines. HIL-3 sup induced EoL-1 cells to express eosinophilic granules and segmented nuclei after 6 to 9 days of incubation. HIL-3 sup also induced the expression of Fc epsilon receptor II (Fc epsilon RII/CD23) and an eosinophil differentiation antigen EO-1 mainly on eosinophilic granule (+) cells. Furthermore, HIL-3 sup induced EoL-1 cells to respond to an eosinophil chemotactic factor, platelet activating factor. HIL-3 cells express messenger RNA (mRNA) of interleukin-5 (IL-5), macrophage colony-stimulating factor (M-CSF), and IL-3 but not granulocyte CSF (G-CSF). Granulocyte-macrophage CSF (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha) were detected in the HIL-3 sup. Recombinant IL-2 (rIL-2), rIL-3, rIL-4, rIL-5, rM-CSF, and rGM-CSF did not induce eosinophilic granules. rG-CSF induced a few eosinophilic granule (+) cells, and TNF-alpha, which did not induce eosinophilic granules by itself, enhanced the ability of G-CSF to induce them. However, G-CSF and TNF-alpha did not induce the expression of Fc epsilon RII and EO-1 antigen. Moreover, anti-G-CSF, anti-TNF-alpha, anti-GM-CSF, anti-IL-3, and anti-IL-5 antibodies did not suppress the effect of HIL-3 sup on the differentiation of EoL-1 cells. All the data suggest that HIL-3 sup contains an unidentified factor that induces differentiation of EoL-1 cells, and that EoL-1 cells and HIL-3 sup provide an important model for the examination of differentiation mechanisms and functions of eosinophils.     

All-trans-retinoic acid counteracts endothelial cell procoagulant activity induced by a human promyelocytic leukemia-derived cell line (NB4)

Therapy with all-trans-retinoic acid (ATRA) can rapidly improve the coagulopathy of acute promyelocytic leukemia (APL). This study was designed to evaluate whether the APL cell line NB4 induces the procoagulant activity (PCA) of human endothelial cells (ECs) in vitro, and whether this property is modified after ATRA-induced NB4 maturation. EC monolayers were incubated for 4 hours at 37 degrees C with the conditioned media (CM) of NB4 treated with 1 mumol/L ATRA (ATRA-NB4-CM) or the vehicle (control-NB4-CM). EC lysates were tested for PCA. ATRA-NB4-CM induced significantly more PCA:tissue factor (TF) than control-NB4-CM (P < .01). To identify the cause of TF induction, interleukin (IL)-1 beta antigen levels were measured in CM samples. ATRA-NB4-CM contained significantly more IL-1 beta than control-NB4-CM. EC PCA was significantly inhibited by an anti-IL-1 beta antibody. The addition to the media of 10 mumol/L ATRA counteracted the EC TF expression induced by NB4-CM. These data indicate that ATRA increases the promyelocyte-induced EC TF, partly through increased IL-1 beta production. However, ATRA can protect the endothelium from the procoagulant stimulus of leukemic cells.     

Purification of a glycoprotein vascular endothelial cell mitogen from a rat glioma-derived cell line.

A growth factor that is mitogenic for vascular endothelial cells, with an ED50 of approximately 1 ng/ml, has been purified 170,000-fold to apparent homogeneity from tissue culture medium conditioned by a rat glioma-derived cell line. The pure protein is a 46-kDa dimer composed of two subunits of equivalent mass as established by comparison of migration in SDS/polyacrylamide gels with and without prior reduction. This glioma-derived growth factor is a glycoprotein and is not mitogenic for BALB/c 3T3 fibroblasts, properties that further distinguish it from other well-characterized vascular endothelial cell mitogens. In contrast to acidic and basic fibroblast growth factors and to platelet-derived endothelial cell growth factor, which have no secretory leader sequences and might only be released by leakage from damaged cells, the glycoprotein nature of this mitogen implies that it is processed through the glycosylating secretory pathway. This secretable growth factor could, therefore, be readily available in the extracellular space under normal physiological conditions in vivo to promote vascular endothelial cell proliferation associated with blood-vessel growth and maintenance.     

Insulin binding by a cell line (HT 29) derived from human colonic cancer.

Insulin binding was demonstrated in cultured HT 29 cells originating from a human colon carcinoma. At 37 degrees and in complete medium, the binding of [125I]insulin (1-4x10-10M) reaches a maximum in 40 min and the cell associated radioactivity remains constant for at least 4 h. No degradation of the hormone is observed under these conditions. The binding is proportional to the number of cells and its pH optimum is 7.8. In the presence of excess insulin 50% of the [125I]insulin is dissociated from the complex after 10 min. At equilibrium, insulin binding is specific: proinsulin is 25 times less potent than native insulin in competing with [125I]insulin and related polypeptide hormones are inactive. Scatchard analysis indicates two classes of binding sites (1400 sites/cell of "high affinity" e.g. 4.7 x 108 M-1, and 20 000 sites of "low affinity" e.g. 4 x 107 M-1). The binding of insulin to this non-target cell shows the same kinetic characteristics and specificity as found for insulin in its target cells, except that HT 29 cells do not degrade the hormone. The problem of the correlation between insulin binding and a biological effect in these cells remains to be elucidated.     

Hormonal effects on cell proliferation in a human erythroleukemia cell line (K562)

We have investigated the hormonal responsiveness of K562 cells using a serum-substituted in vitro clonogenic assay. Dexamethasone inhibited colony formation by the K562 cells, and the inhibitory effect could be reversed by progesterone (10(-6) M). Fluoxymesterone caused a prominent enhancement of K562 colony growth, whereas estriol had no effect. Stimulation by triiodothyronine was maximal at 10(-7) M, and the thyroid effect could be abrogated by the beta 2-adrenergic antagonist butoxamine in equimolar concentrations. Using standard tissue culture conditions, the beta-adrenergic agent isoproterenol, but not the alpha catecholamine phenylephrine, enhanced the proliferation of K562 cells. When K562 cells were grown under hormone-depleted conditions, they developed responsiveness to phenylephrine and were no longer stimulated by isoproterenol. DbcAMP and prostaglandins of the E series also caused K562 colony enhancement. Prostaglandin F2 alpha had no effect on cell proliferation. Insulin was an effective stimulant of colony formation of K562 cells, as were human growth hormone and ovine prolacin. Bovine growth hormone had no effect. Our results are consistent with the identificaiton of K562 as an erythroid line, and they indicate that K562 cells respond to endocrine hormones in a manner analogous to normal erythroid progenitors.     

阿托伐他汀钙对EA.hy926细胞全基因表达谱的影响及生物信息学分析

目的探讨阿托伐他汀钙对体外培养人脐静脉内皮细胞EA.hy926细胞基因表达谱的影响及作用的分子机制。方法取EA.hy926细胞分实验组和对照组,实验组采用10μmol/L阿托伐他汀钙体外干预人脐静脉内皮细胞EA.hy926 24h,用Affymetrix HG-U133plus 2.0全基因组表达芯片检测阿托伐他汀钙对EA.hy926细胞基因表达谱的影响。并运用基因富集分析(GSEA)软件、DAVID基因功能聚类分析软件及Cmap数据库对芯片数据进行分析,对相关靶基因进行实时定量PCR验证。结果与对照组比较,实验组基因芯片分析筛选出差异表达倍数>2倍的基因649个,其中上调基因295个,下调基因354个。经DAVID及GSEA基因富集分析显示,阿托伐他汀钙广泛下调了细胞周期调控相关基因,上调了Kruppel样转录因子等血管保护基因,Cmap数据库分析显示,阿托伐他汀钙与组蛋白去乙酰化酶抑制剂及白藜芦醇呈正相关的联强度高。结论阿托伐他汀钙从多角度发挥抗动脉粥样硬化作用,作用机制可能与组蛋白去乙酰化酶抑制剂及白藜芦醇相似。     

汉滩病毒感染EA.hy926细胞上调固有免疫相关分子表达的研究

目的　探讨汉滩病毒（hantaan virus, HTNV）感染EA.hy926细胞诱导抗病毒固有免疫相关分子的表达,为建立HTNV感染的细胞模型提供依据。方法　将HTNV感染EA.hy926细胞,利用间接免疫荧光和实时荧光定量PCR技术于不同感染时间段,检测EA.hy926细胞中模式识别受体、细胞因子及抗病毒相关分子的mRNA表达水平。结果　HTNV感染EA.hy926细胞后,随着感染时间的持续,核蛋白mRNA相对表达倍数显著上调,且不同感染时间段差异具有统计学意义（P＜0.05）;与未处理组相比,HTNV感染EA.hy926后,Toll样受体3、RIG-I和MDA5模式识别受体mRNA相对表达倍数均显著上调（P均＜0.05）,IL-6、IL-10、IFN-β和CCL5细胞因子mRNA相对表达倍数均显著上调（P均＜0.05）,ISG15、MxA、OAS1、IFITM1和IFITM3抗病毒相关分子mRNA相对表达倍数均显著上调（P均＜0.05）。结论　HTNV感染EA.hy926细胞后,可上调抗病毒固有免疫相关分子的表达,该细胞可以作为体外HTNV感染的细胞模型。     

Isolation and characterization of a highly enriched preparation of receptosomes (endosomes) from a human cell line.

Receptor-mediated endocytosis proceeds by transfer of receptor-ligand complexes from clathrin-coated pits at the cell surface to uncoated endocytic vesicles termed receptosomes (or endosomes). These vesicles have now been purified more than 37-fold based on their content of newly internalized epidermal growth factor. 125I-labeled EGF was bound to human KB carcinoma cells at 4 degrees C, and then the cells were warmed to 37 degrees C for 8 min and disrupted. The purification scheme involved density gradient centrifugation on colloidal silica and sucrose and gel filtration on Sephacryl S-1000. Relative to homogenate, receptosomes are enriched 4.3-fold in their cholesterol content and depleted in enzyme markers for plasma membranes (2- to 3-fold) and lysosomes (9-fold). Receptosomes have a polypeptide composition that is different from plasma membrane, lysosome, and other homogenate fractions. They are enriched in transferrin receptors (30-fold) and in unidentified Mr 70,000-75,000 glycoprotein(s); they contain phosphomannosyl receptors. They do not contain detectable amounts of clathrin.     

Production of erythroid potentiating factor(s) by a human monocytic cell line

U-937 is a human monocytic cell line that has been to elaborate factors that affect normal human hematopoiesis in vitro. Studies on the effects of these factors demonstrated an erythroid potentiating factor (EPF) and a potent inhibitor of granulocyte-macrophage (CFU-GM) colony growth. The EPF was present in both serum-containing and serum-free U- 937 conditioned media, had a dose-dependent effect on erythroid colony formation and was remarkably heart stable. The CFU-GM inhibitory activity was also detected in serum-free conditioned medium, was dose- dependent, heart labile and its effect was reversed by Indomethacin. Indomethacin (Sigma, St. Louis, Mo.) did not alter the erythroid effects of the U-937 conditioned medium. No colony stimulating factor (CSF) or erythropoietin (Ep) could be detected in this medium. The existence of a human cell line capable of production EPF without simultaneous CSF production will permit further studies on the biochemical and biologic nature of these factors.     

Identification of arrestin-like proteins in a human megakaryocytic cell line (HEL cells)

Proteins of the arrestin family contribute to the regulation of G-protein-mediated signal transduction in a number of tissues, possibly by a desensitization of the appropriate receptor(s). In this study we demonstrate the presence of arrestin-related proteins in a megakaryoblast-like cell line (HEL). Mouse monoclonal and rabbit polyclonal antibodies were prepared against visual arrestin, against a synthetic peptide'GFLGELTSSEVATEVPFRLM' (a pathogenic sequence corresponding to residues 340 to 359 of human visual arrestin), and against the peptide 'VDTNLIEFDTNDDDIV' that represents an aminoacid sequence present in beta -arrestins 1 and 2 but absent from visual arrestin. In Western blots, all of these antibodies revealed a 48-kDa protein in HEL cell extract. Using a beta-arrestin specific primer, RT-PCR of RNA from HEL cells confirmed the presence of beta-arrestin mRNA, with a predicted 480 bp having 98.8% homology with beta-arrestin. These results suggest that arrestin-family proteins may be involved in the desensitization of G-protein mediated receptors in platelets.     

Leukemia-derived growth factor (non-interleukin 2) produced by a human malignant T lymphoid cell line.

A growth factor was found in the supernatants of MOLT-4f, a cell line derived from acute T lymphoblastic leukemia. This factor, which we designated leukemia-derived growth factor from MOLT-4f (LDGF-M4), is different from interleukin 2. LDGF-M4 has features of a polypeptide with a molecular weight in the range of 5,000-15,000, as indicated by gel diffusion chromatography. LDGF-M4 does stimulate MOLT-4f and at least two other T cell lines that do not respond to interleukin 2. Because MOLT-4f cells produce and respond to LDGF-M4, this factor may contribute to the independence of MOLT-4f and related T leukemia cell lines.     

Characterization of a transformed ovine lymphatic endothelial cell line

OBJECTIVE: To develop a non-tumor-derived stable lymphatic endothelial cell line that exhibits rapid growth rate without serum and exogenous growth factors, while still maintaining key features characteristics of the non-transformed lymphatic endothelium. METHODS: Lymphatic endothelial cells were isolated from ovine mesenteric lymphatic vessels, grown to confluence and transfected with SV40 DNA using the calcium phosphate method. The resulting cell line was characterized using morphological, immunocytochemical, flow cytometric analysis, and immunoprecipatitation and Western blotting methods. RESULTS: The resulting cell line (sheep lymphatic endothelial transformed cell line, SLET-1) underwent rapid proliferation in the absence of growth factors and reduced concentrations of serum. In addition, key morphological and functional properties of the non-transformed lymphatic endothelium were retained. These include the ability to form confluent monolayer cultures, the expression of the lymphatic endothelial-specific VEGFR-3, FLT-4) tyrosine kinase receptor, the biosynthesis and secretion of von Willebrand factor and plasminogen activators. In addition, SLET-1 cells express cell surface antigens found on LEC that may act as antibody targets in various immune reactions. Monolayer cultures of the SLET-1 cells incubated with endothelial cell-growth factor formed tubular structures, indicating the retention of the capacity to differentiate. CONCLUSION: The SLET-1 cell line retained key morphological and functional properties characteristic of the non-transformed lymphatic endothelium. The ability to form capillary-like tubular structures provides an important cell line for defining the role of specific proteins that are involved in the lymphagiogenic (formation of new lymphatic vessels) process. Thus, this transformed lymphatic endothelial cell line provides an in citro model that may have widespread utility in studying regulatory mechanisms of lymphatic endothelial cell function and differentiation.     

小干扰RNA对人内皮细胞株类表皮生长因子域7基因表达抑制作用的实验研究

目的 研究小干扰RNA（siRNA）对类表皮生长因子域7（egfl7）基因表达的抑制作用。方法 利用Ambion公司设计合成的以egfl7为靶标的siRNA,通过脂质体将siRNA转入人脐静脉内皮细胞株,以未转染siRNA细胞和转染无关siRNA细胞为对照,利用MTS[3-（4,5-dimethyhhiaz-2-y1）-5（3-carboxymethoxyphenyl）-2-（4-sulfopheny）-2H-tetrazolium,innersalt]法检测siRNA对细胞存活率的影响,同时检测乳酸脱氢酶和三磷酸腺苷,观察siRNA对细胞生长的影响,RT-PCR法检测egfl7mRNA水平的改变,Westernblot检测egfl7蛋白表达的变化。结果 siRNA各组与对照组细胞存活率差异均有统计学意义（P〈0．05）,乳酸脱氢酶及三磷酸腺苷释放量差异也存在统计学意义（P〈0．01）。转染24h后,siRNA组egfl7mRNA与对照组相比差异有统计学意义（P〈0．01）,同时egfl7蛋白表达也被明显抑制（P〈0．01）,其中siRNA1的抑制效率最高。结论 体外转录合成的siRNA可抑制人脐静脉内皮细胞egfl7基因的表达。     

Persistent infection of a human lymphocyte cell line (Molt-4) with the kilham rat virus.

Inoculation of a human thymus-derived lymphocyte cell line (Molt-4) with the Kilham rat virus resulted in persistently infected cultures, that released infectious virus for periods up to seven months. At any time following infection, a small percentage of the cells were positive for rat virus antigens as determined by immunofluorescene assay.     

Embryonic-fetal erythroid characteristics of a human leukemic cell line.

We have studied a number of cell surface, enzyme, and protein markers in the human leukemic K562 cell line. We have confirmed previous observations that these cells accumulate human embryonic hemoglobins after exposure to hemin. In addition, our results demonstrated that these cells possess in the "ininduced" state i surface antigen, lactate dehydrogenase isoenzymes characteristic of embryonic or fetal erythroid cells, fetal and embryonic globin chains, and globin mRNAs. The levels if i antigen, embryonic globin chains, and embryonic globin mRNA increased substantially after exposure of the cells to hemin in suspension culture. In contrast, K562 cells lacked several surface, enzymatic, and functional properties typical of granulocytes, lymphocytes, monocytes, or adult erythroblasts, including HLA surface antigens, surface immunoglobulins, sheep erythrocyte rosetting, phagocytosis, terminal deoxynucleotidyl transferase, carbonic anhydrase, ABO and Rh blood groups, and adult hemoglobins. The K562 cell line therefore exhibits phenotypic properties of embryonic erythroid progenitor cells and a quantitative increase in the expression of some of these properties can be achieved by exposure of the cells to hemin.     

棕榈酸对EA.hy926细胞胆固醇代谢相关基因表达的影响及机制

目的研究棕榈酸(PA)对内皮细胞株EA.hy926胆固醇代谢的影响,检测胆固醇流出、胆固醇胞内转化、脂蛋白摄入以及信号通路相关基因表达的变化。方法体外培养内皮细胞株EA.hy926,分为白蛋白(ALB)对照组和PA处理组。采用实时荧光定量PCR法检测ATP结合盒转运体A1(ABCA1)、ABCG1、27-羟化酶、清道夫受体A1(SR-A1)、SR-B1、CD36、凝集素样氧化低密度脂蛋白受体1(LOX-1)、肝X受体α(LXRα)、过氧化物酶体增殖物激活受体γ(PPARγ)的表达变化。结果和ALB对照组相比,10、20、30μmol/L PA处理组ABCG1 mRNA水平显著下降(P0.01),20、30μmol/L PA处理组CD36、LOX-1 mRNA水平显著升高(P0.05)。与ALB对照组相比,10、20、30μmol/L PA处理组LXRαmRNA水平显著下降(P0.001、P0.05、P0.001),10μmol/L PA处理组PPARγmRNA水平显著下降(P0.05)。而10、20、30μmol/L PA处理EA.hy926细胞未显著影响ABCA1、SR-A1、SR-B1、27-羟化酶的表达。结论 PA能够改变内皮细胞EA.hy926细胞胆固醇流出和脂蛋白摄入相关基因的表达,其机制与LXRα和PPARγ信号途径有关。     

Characteristics of a cell line (Tong/HCC) established from a human hepatocellular carcinoma

A continuous adherent cell line was established from a hepatocellular carcinoma of an HBsAg-positive Italian male. This cell line, designated Tong/HCC, has been grown in a hormone-supplemented medium for more than 18 months. The cell line secretes HBsAg, alpha-fetoprotein, albumin and alpha 1-antitrypsin. alpha-Fetoprotein production is enhanced by the addition of hydrocortisone and appears to be glucocorticoid concentration-dependent. The concentrates of the supernatant from the cell cultures and cell lysates were negative when tested for HBeAg. The cell culture medium was negative for hepatitis B virus DNA when tested by dot-blot hybridization. However, hepatitis B virus DNA was found to be integrated in the chromosomal DNA by Southern blot analysis. At least five different integration sites were identified, and no free hepatitis B virus DNA was observed. The modal chromosome number was 64, and a translocation on Chromosome 15 was consistently noted. HLA typing revealed sites for A3, Aw24, Bw34 and Cw1.