Development and verification of a rapid detection method for adalimumab biological activity based on U937-NF-κB-Luc cell line / 中国生物制品学杂志

@#Objective To develop and verify a rapid detection method for the biological activity of adalimumab based on U937-NF-κB-Luc cell line. Methods Using U937-NF-κB-Luc cell line as the detection cells,a method for detecting the biological activity of adalimumab was developed based on luciferase luminescence principle. The method was optimized for the concentration of tumor necrosis factor-α(TNF-α)(160 ng/mL as initial concentration,2 times serial dilution,10dilutions),the initial concentration of antibody(2 000 ng/mL,2 times serial dilution,20 dilutions),the dilution multiple of antibody(1. 5,2,3,4 times),the inoculation amount(8 × 103,2 × 104,4 × 104,6 × 104cells/well)and the incubation time(0. 5,1,2,3 h),and verified for the specificity,accuracy,precision and linear range. The relative potency of five batches of adalimumab was detected by using the optimized method and TNF-α neutralization activity method based on L929cells respectively. Results The dose-response curve of adalimumab international standard showed a typical S-type,and the data complied with the four-parameter equation y =(A-D)/[1 +(x/C)B]+ D,R2> 0. 99. The optimum concentration of TNF-α was 5 ng/mL,the initial concentration of antibody was 800 ng/mL,the dilution ratio for adalimumab was 1∶2,the inoculation amount was 2 × 104cells/well,and the induction time was 2 h. Three therapeutic monoclonal antibodies of TNF-α target,such as adalimumab,obtained good dose-response curves,while therapeutic monoclonal antibodies of other non-TNF-α targets did not show this curve. The linear regression equation of the logarithmic value of theoretical potency and the logarithmic value of the corresponding measured potency had a slope of 1. 037,and the relative bias was within the range of ± 12%. The geometric coefficient of variation(GCV)of the relative titer measured value of each sample was less than20%. The theoretical potency ranged from 64% to 156%,showing a good linear relationship with the measured values,and the fitting linear regression equation was y = 1. 037 4 x-0. 023 7,R2= 0. 998 4. There was no significant difference in the relative potency measured results of five batches of adalimumab by the two methods(t = 1. 198,P = 0. 265 1). Conclusion The developed detection method for adalimumab biological activity based on U937-NF-κB-Luc cell line has good specificity,accuracy and precision with short time consumption(3 h),which can be used as a rapid evaluation method for the biological activity of adalimumab.

Establishment of leukemia cell model with inducible AML1-ETO expression and its effect on fatty acid metabolism in leukemia cells / 中华血液学杂志

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (P<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (P<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (P<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (P<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (P<0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.

Citotoxicidad in vitro del polipéptido antimicrobiano nisina sobre células tumorales sanguíneas / In vitro cytotoxicity of the antimicrobial polypeptide nisin on blood tumor cells

RESUMEN: Las bacteriocinas son péptidos antimicrobianos de síntesis ribosomal secretadas por bacterias. Dentro de estas destaca nisina que posee potenciales usos en terapias antibióticas, como biopreservante de alimentos y probióticos. También se ha descrito que nisina posee citotoxicidad sobre líneas celulares neoplásicas, pero existe poca información de su efecto sobre células tumorales sanguíneas. Debido al potencial uso que presenta nisina, es relevante determinar la toxicidad que presenta sobre líneas celulares tumorales del tipo sanguíneo. Para esto, se realizaron ensayos de actividad hemolítica sobre eritrocitos humanos y de toxicidad sobre células mononucleares de sangre periférica humanas, determinándose que nisina no posee efecto citotóxico sobre este tipo de células normales humanas sanguíneas. Se realizaron también, ensayos de citotoxicidad con líneas celulares tumorales (K562 y U937), con el fin de determinar dosis, tiempo de exposición y selectividad en el efecto tóxico de nisina sobre las células tumorales humanas. Estos ensayos muestran que nisina presenta actividad citotóxica sobre líneas celulares K562 y U937 a las 72 h de exposición, a una concentración de 40 µg/mL, que corresponde a 100 veces la concentración mínima inhibitoria (MIC) usada para su acción sobre bacterias. Al comparar el efecto de nisina sobre células mononucleares de sangre periférica humanas con las líneas tumorales linfoides y mieloides (K562 y U937 respectivamente), se observa un efecto selectivo de nisina sobre las células tumorales sanguíneas.

SUMMARY: Bacteriocins are antimicrobial peptides of ribosomal synthesis secreted by bacteria. Among these, nisin stands out, which has potential uses in antibiotic therapies, as a food bio preservative and probiotics. Nisin has also been reported to have cytotoxicity on neoplastic cell lines, but there is little information on its effect on blood tumor cells. Due to the potential use that nisin presents, it is relevant to determine the toxicity it presents on tumor cell lines of the blood type. For this, hemolytic activity tests were carried out on human erythrocytes and toxicity on human peripheral blood mononuclear cells, determining that nisin does not have a toxic effect on this type of normal human blood cells. Cytotoxicity tests were also carried out with tumor cell lines (K562 and U937), to determine dose, exposure time and selectivity in the toxic effect of nisin on human tumor cells. These tests show that nisin shows cytotoxic activity on K562 and U937 cell lines at 72 h of exposure, at a concentration of 40 µg / mL, which corresponds to 100 times the minimum inhibitory concentration (MIC) used for its action on bacteria. When comparing the effect of nisin on human peripheral blood mononuclear cells with lymphoid and myeloid tumor lines (K562 and U937 respectively), a selective effect of nisin on blood tumor cells is observed.

Induction of Apoptosis Scutellaria baicalensis Georgi Root Extract by Inactivation of the Phosphatidyl Inositol 3-kinase/Akt Signaling Pathway in Human Leukemia U937 Cells

BACKGROUND: The roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used in traditional medicine for treatment of various diseases. In this study, we investigated the effects of ethanol extracts of S. baicalensis roots (EESB) on the growth ofn human leukemia U937 cells. METHODS: The effect of EESB on cell viability was measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Apoptosis was determined using 4,6-diamidino-2-phenyllindile staining and flow cytometry. The effects of EESB on the expression of regulatory proteins of apoptosis and phosphatidyl inositol 3-kinase (PI3K)/Akt signaling were determined by Western blotting. Caspase activity and mitochondrial membrane potential (MMP) were measured using flow cytometric analysis.

Effects of XPO1 Inhibitor KPT-8602 on Proliferation and Apoptosis in U937 cells / 中山大学学报(医学科学版)

@#【Objective】To explore the effects and the possible mechanism of KPT- 8602，a novel selective inhibitor of nuclear export protein （XPO1），on proliferation，cell cycle and apoptosis in human histiocytic lymphoma cell line U937 cells.【Methods】U937 cells were treated with different concentrations of KPT- 8602. Cell viability was assessed by CCK-8 assay. The cell cycle distribution and the apoptosis rate were analyzed by flow cytometry. The proteins expression of XPO1，p-AKT，AKT，Cleaved Caspase-3，p21 were determined by Western blot. Fluorescence microscope was used in observing the intracellular location of XPO1. 【Results】 KPT- 8602 inhibited the growth of U937 cells in a dose- dependent（P<0.001）and time- dependent manner（P<0.001），but normal PBMC were unaffected. 48 h after treatment with KPT-8602，a higher proportion of cells in G1 phase was observed（P<0.001）and the apoptosis rate increased（P=0.016）with drug concentration in U937 cells. XPO1 protein expression of U937 cells was significantly higher than normal PBMC（P=0.003）. 48 h after treatment with KPT- 8602，the protein expression of XPO1 decreased（P=0.011），p-AKT decreased（P=0.011），and Cleaved Caspase- 3 increased（P=0.009）. In addition，the protein expression of p21，the cargo protein of XPO1，increased in both the nuclei and the cytoplasm（P<0.05）after treatment with KPT- 8602. XPO1 decreased in both the nuclei and the cytoplasm under the fluorescence microscope after treatment with KPT- 8602.【Conclusion】KPT- 8602 can inhibit the proliferation of U937 cells，block the cell cycle at G1 phase，and induce cell apoptosis，which may partially be attributed to the down-regulation of XPO1 and inhibition of PI3K/AKT signaling.

Screening of the anti-atherogenic drugs by using THP-1-HIF-1α-HER-Luciferase cell model / 上海交通大学学报（医学版）

Objective: To screen the anti-atherosclerosis (AS) activity of the compounds by using THP-1-HIF-1α-HER-Luciferase high-throughput model, and to verify the anti-AS function of the effective compounds. Methods: THP-1-HIF-1α-HER-Luciferase cells were pretreated with different concentrations of compounds (1, 10, and 100 μg/mL) for 2 h, then cultured under hypoxia for 24 h. Luciferase activity of cells was detected and compounds with anti-AS activity were screened by luciferase activity evaluation. THP-1 and U937 cells were pretreated with effective compounds, and then induced for 24 h by oxidized low density lipoprotein (OX-LDL). The formation of foam cells was observed by oil red staining. The mRNA level of hypoxia-inducible factor 1α (HIF-1α) was detected by real-time quantitative PCR (qPCR). HIF-1α protein expression was detected by Western blotting. Anti-AS activity of effective compounds were evaluated. Results: Among the 200 compounds, 11 compounds could significantly inhibit the increase of luciferase activity in THP-1-HIF-1α-HER-Luciferase cells induced by hypoxia (all P<0.05), and compound numbered 14 (C14) had the most significant inhibitory effect. THP-1 and U937 cells formed foam cells induced for 24 h by OX-LDL. However, cells were pretreated with C14 for 2 h, which could significantly inhibit the formation of foam cells induced by OX-LDL. Cells were induced for 24 h by OX-LDL, which could significantly increase the expression of HIF-1α mRNA and protein (all P<0.05), while cells pretreated with C14 could significantly inhibit the increase of HIF-1α mRNA and protein expression in a gradient-dependent manner (all P<0.05). Conclusion: THP-1-HIF-1α-HER-Luciferase high-throughput model can be reliability used in screening of compounds with anti-AS activity. C14 has the good anti-AS activity characteristics.

Depression and Mania Induce Pro-inflammatory Activation of Macrophages Following Application of Serum from Individuals with Bipolar Disorder

OBJECTIVE: Evidence has suggested that immune imbalance is involved with bipolar disorder (BD); however, its precise mechanism is poorly understood. This study investigated whether biochemical changes in the serum from BD patients could modulate the phenotype of cultured macrophages. METHODS: Eighteen subjects with BD and five healthy individuals were included in this study. The human monocyte cell line U-937 was activated with phorbol 12-myristate 13-acetate (PMA) and polarization was induced with RPMI-1640 media supplemented with 10% serum from each patient for 24 hours. Gene expression of selected M1 and M2 markers was assessed by quantitative PCR. RESULTS: Macrophages exposed to serum of manic and depressive BD patients displayed an increase of interleukin-1β (6.40±3.47 and 9.04±5.84 vs. 0.23±0.11; p < 0.05) and tumor necrosis factor-α (2.23±0.91 and 2.03±0.45 vs. 0.62±0.24; p=0.002 and p=0.004, respectively) compared to euthymic group (there was no difference between euthymic and controls). In parallel, U-937 macrophages treated with serum of patients in acute episode displayed a down-regulation of CXCL9 (0.29±0.20 vs. 1.86±1.61; p=0.006) and CXCL10 expression (0.36±0.15 and 0.86±0.24 vs. 1.83±0.88; p < 0.000 and p=0.04) compared to the euthymia group. CONCLUSION: Our results are consistent with previous studies showing that changes in peripheral blood markers could modulate M1/M2 polarization in BD. The evidence of macrophages as source of inflammatory cytokines might be helpful to unravel how the mononuclear phagocyte system is involved in the etiology of BD.

Inhibitory effect of JQ1 on proliferation of acute myeloid leukemia U937 cell line and its effect on the signal transduction pathway of STAT-5 / 白血病·淋巴瘤

Objective To study the suppressive mechanism of the bromo structural domain inhibitor JQ1 on the acute myeloid leukemia cell line U937 and its regulation of the STAT-5 signaling pathway. Methods U937 cells in the logarithmic growth phase were tested. Each experimental group was fed with 0.2, 1.0 and 4.0μmol/L of JQ1, and a blank control group without JQ1 was set up. U937 cells were cultured for 48 h, and the cell proliferation inhibitory rate was measured by MTT assay. Flow cytometry (FCM) was used to detect the apoptotic rate. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of focal adhesion kinase (FAK) and P21 activated kinase (PAK1). The expression of STAT-5 protein was analyzed by Western blot. Results Different concentration of JQ1 could inhibit the proliferation of U937 cells in a time and dose-dependent manner, and different concentration of JQ1 could induce the apoptosis of U937 cells in a dose-dependent manner. Treatment of U937 cells with different concentrations of JQ1 (0.2, 1.0 and 4.0 μmol/L) reduced the expression of FKA mRNA and PAK1 mRNA after 48 h, the expression of FAK mRNA was 0.417±0.066, 0.140±0.026, and 0.027±0.006 (F=454.651, P=0.000), and the expression of PAK1 mRNA was 0.533±0.045, 0.080±0.010, and 0.010±0.001 (F=2434.610, P= 0.000), and STAT-5 protein expression was also significantly inhibited. The expression of STAT-5 protein in U937 cells after treated with different concentrations of JQ1 (0.2, 1.0 and 4.0 μmol/L) for 48 h were 0.71± 0.19, 0.62±0.16, 0.53±0.14, and 1.00±0.21 in the control group (F= 263.135, P= 0.000). Conclusion JQ1 can effectively inhibit the proliferation of the acute myeloid leukemia cell line U937 cells and induce their apoptosis, and the possible mechanism of action is regulated via STAT-5 signaling pathway.

Manumycin-induced apoptosis in U937 human myeloid leukemia cells via blocking PI3K/Akt signaling pathway / 实用医学杂志

Objective To explore the effects of manumycin on U937 cells and its mechanisms.Methods Apoptosis was detected by flow cytometry using annexin V and propidium iodide (PI) after treatment with manumycin (2 μmol/L) for different time.The reactive oxygen species (ROS) was detected by flow cytometry using Reactive Oxygen Species Assay Kit.The expressions of PI3K,P-Akt and Akt were detected by Western blotting.Results Compared with the 0 h treatment,manumycin treatment resulted in apoptosis (P ＜ 0.05) and ROS generation (P ＜ 0.05) gradually in U937 cell lines.Furthermore,manumycin also inhibited the activation of phosphatidylinositol-3 kinase (PI3K)/Akt pathway.Moreover,NAC could decrease manumycin-induced ROS generation and inhibit the effects of manumycin on the PI3K/Akt pathway and protect U937 cells from apoptosis induced by manumycin.Conclusion Manumycin induces apoptosis in U937 human leukemia cells through the regulation of the PI3K/Akt pathway and ROS production plays a critical role in the progress.

Effect of metformin on proliferation,cell cycle and apoptosis of U937 cells / 中国免疫学杂志

Objective:To study the effect of metformin on proliferation,cell cycle and apoptosis of U937 cells.Methods: U937 cells were treated with different concentrations of metformin,collected cells in 24,48 and 72 hours.Subsequently,cell proliferation was assessed by CCK-8 assay,and the cell cycle and apoptosis were analyzed by flow cytometry (FCM).The expression of Bcl-2,Bax,p-AMPK,p53 were determined by Western blot.Results: The proliferation of U937 cells was inhibited by metformin in a time-and dose-dependent manner.Metformin-treated cells were arrested at G0/G1 phase,the cell frequency at G0/G1 phase was increased in a time-and dose-dependent manner.Metformin also induced cell apoptosis in a dose-dependent manner.It showed that 20 mmol/L metformin induced cell apoptosis in a time-dependent manner.The expression of p-AMPK,p53,Bax was up-regulated while Bcl-2 expression was down-regulated after metformin treatment.Conclusion: Metformin could inhibit the U937 cell proliferation,block the cell cycle at G0/G1 phase,and induce cell apoptosis,which may partially be attribute to the up-regulation of Bax,down-regulation of Bcl-2,activation of AMPK/p53 signaling.

Telmisartan inhibits proliferation and induces apoptosis in U937 cells / 中国病理生理杂志

AIM: To demonstrate the effects of telmisartan on the proliferation and apoptosis of U937 cells.METHODS: The proliferation ability of the U937 cells was assessed by CCK-8 assay and colony formation test with methylcellulose.The CD11b expression rate of the U937 cells was identified by flow cytometry.The apoptotic rate was analyzed by flow cytometry with Annexin V-PI double staining and Hoechst 33342 staining.The protein levels of cleaved PARP and cleaved caspase-3 were determined by Western blot.RESULTS: The results of CCK-8 assay confirmed that the viability of U937 cells was inhibited by telmisartan.The colony formation capacity of U937 cells was also significantly inhibited by telmisartan.The differentiation of U937 cells was induced by telmisartan with the expression of CD11b.The results of flow cytometry analysis with Annexin V-PI double staining and Hoechst 33342 staining identified that the apoptosis of U937 cells was induced by telmisartan in dose-dependent and time-dependent manners with the up-regulation of cleaved PARP and cleaved caspase-3 proteins.CONCLUSION: Telmisartan inhibits the proliferation and induces the differentiation of U937 cells.Telmisartan also induces the apoptosis of U937 cells through the caspase pathway.

Promotion of immune response by soluble Tim-3 in vitro and therapeutic potential / 军事医学

Objective To evaluate the role of recombinant human soluble Tim-3 (hTim-3-Fc) in regulating immune response.Methods Soluble hTim-3 was incubated with human macrophage cell line U 937, human T cell line Jurkat and normal human PBMC before cytokines secreted by or expressed in different immune cells were analyzed using ELISA , RT-PCR and Western-blotting, respectively.Results Soluble hTim-3 significantly promoted the activation of different immune cells.Our data showed that IL-8 secretion by U937 cells, IL-2 secretion by Jurkat cells , IL-2 and IFN-γsecretion by human PBMCs were all significantly increased .In addition , soluble hTim-3 significantly increased the IFN-α2 and IFN-β1 mRNA expression in U937, Jurkat and PBMCs and increased the phosphorylation of stat-1 in Jurkat and U937 cells.Conclusion Recombinant soluble hTim-3 can significantly promote the activation of immune cells in vitro, which shows its therapeutic potential .

Composición lipídica y evaluación de las actividades antioxidante y leishmanicida del basidiomiceto Ganoderma sp / Lipid composition and evaluation of the antioxidant and leishmanicidal activities of the basidiomycete Ganoderma sp

Introducción: los hongos del género Ganoderma han sido utilizados para el cuidado de la salud en la medicina tradicional asiática por más de 2000 años. Desde 1980 los estudios químicos han reportado un sin número de metabolitos secundarios con propiedades bioactivas. Objetivo: identificar compuestos lipídicos en el extracto etanólico del hongo Ganoderma sp., además de evaluar sus actividades antioxidante y leishmanicida. Métodos: la extracción de las fracciones lipídicas presentes en el cuerpo fructífero de Ganoderma sp. Se realizó por Cromatografía en Columna. La elucidación estructural se determinó por Espectrometría de Masas y Resonancia Magnética Nuclear. La actividad antioxidante del extracto etanólico fue evaluada con las metodologías del radical 2,2-difenil-1-picrilhidrazil (DPPH) y el radical catiónico 2,2'-azinobis (3-etilbenzotiazolina-6-ácido sulfónico) (ABTS); la actividad leishmanicida por citometría de flujo y la actividad citotóxica usando el ensayo colorimétrico de bromuro de 3-(4,5-dimetil-tiazol-2-il)-2,5-difenil tetrazolio (MTT) sobre la línea celular U937. Resultados: diecinueve esteres metílicos y ergosterol fueron identificados por espectrometría de masas en el extracto etanólico. Un compuesto triterpenoidal se elucidó usando Espectroscopia de Resonancia Magnética Nuclear. Los valores de concentración media inhibitoria (IC 50) de la actividad antioxidante del extracto etanólico para las metodologías de los radicales DPPH y ABTS fueron de 85,63 µg/mL y 62,82 µg/mL, respectivamente. Los valores de las actividades citotóxica y leishmanicida fueron > 200,0 µg/mL y 21,5 µg/mL ± 4,4 respectivamente. Conclusiones: las estructuras de los derivados de ácidos grasos elucidados corresponden a compuestos con diferentes grados de insaturación. En este estudio se realizó el reporte de la Ganoderona A, como compuesto triterpenoidal. La elevada actividad antioxidante en relación a otros trabajos sugiere que este organismo es una fuente importante de metabolitos secundarios con propiedades captadoras de radicales libres, aunque los valores de actividad leishmanicida no fueron significativos se recomienda continuar con el estudio de otras particiones del extracto etanólico(AU)

Introduction: Fungi from the genus Ganoderma have been used in Asian traditional medicine for more than 2 000 years. Since the year 1980 chemical studies have reported a large number of secondary metabolites with bioactive properties. Objective: Identify lipid compounds in ethanolic extract from the fungus Ganoderma sp. and evaluate their antioxidant and leishmanicidal activities. Methods: Extraction of lipid fractions from the fruiting body of Ganoderma sp. was conducted by column chromatography. Structural features were determined by mass spectrometry and nuclear magnetic resonance. Antioxidant activity of the ethanolic extract was evaluated with the methodologies for radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and cationic radical 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS); leishmanicidal activity by flow cytometry, and cytotoxic activity with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay (MTT) on cell line U937. Results: Nineteen methyl esters and ergosterol were identified by mass spectrometry in the ethanolic extract. A triterpenoid compound was identified by nuclear magnetic resonance spectroscopy. Mean inhibitory concentration values (IC50) for antioxidant activity of the ethanolic extract using the methodologies for radicals DPPH and ABTS were 85.63 µg/ml and 62.82 µg/ml, respectively. Values for cytotoxic and leishmanicidal activities were > 200.0 µg/ml and 21.5 µg/ml ± 4.4, respectively. Conclusions: The structure of the fatty acid derivatives identified corresponds to compounds with varying degrees of unsaturation. The study included the report of Ganoderma A as a triterpenoid compound. Antioxidant activity was found to be higher than in previous studies, suggesting that this organism is an important source of secondary metabolites with free radical scavenging properties. Although leishmanicidal activity values were not found to be significant, it is recommended to study other partitions of the ethanolic extract(AU)

Zoledronic acid inhibits proliferation and induces apoptosis in U937 cells / 中国病理生理杂志

[ ABSTRACT] AIM:To study the antiproliferation and proapoptotic effects of zoledronic acid ( ZOL) on human a-cute myeloid leukemia cell line U937.METHODS:The viability of U937 cells was detected by CCK-8 assay.The cell cy-cle of the U937 cells was analyzed by flow cytometry with PI staining.Apoptotic rate was assessed by flow cytometry with Annexin V-PI and Hoechst 33342 staining.Mitochondrial membrane potential was detected by JC-1 assay.Methylcellulose was used to assess colony formation.The protein levels of p21, Bcl-2 and Bax were determined by Western blot.RE-SULTS:ZOL inhibited the viability of U937 cells.ZOL induced S-phase cell cycle arrest in the U937 cells.The results of flow cytometry analysis with Annexin V-PI and Hoechst 33342 staining showed that ZOL also induced apoptosis in a dose-and time-dependent manner.Mitochondrial membrane potential assay was also used to verify the apoptosis.The apoptotic rate was consistent with the reduction of mitochondrial membrane potential.Colony formation assay showed that ZOL signifi-cantly inhibited the colony formation capacity of the U937 cells.This was achieved by the induction of S-phase cell cycle arrest, and up-regulation of Bax and p21, and down-regulation of Bcl-2.CONCLUSION:ZOL inhibits cell proliferation by regulating the expression of cell cycle-related protein, and induces apoptosis via the mitochondrial apoptotic pathway.

Proteomic profile of human monocytic cells infected with dengue virus

Objective To identify the changes in the proteome of U937 cells infected with dengue virus (DENV). Methods In this study, differentiated U937 cultures were infected with two DENV-2 strains, one of which was associated with dengue (DENV-2/NG) and the other one with severe dengue (DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and separated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity. Results In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially (five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed (two were downregulated and four were upregulated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 kDa protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 kDa protein AA1, tubulin beta, enolase 1, pyruvate kinase, transaldolase and phospholipase C-alpha. Conclusions Because the monocyte/macrophage lineage is critical for disease pathogenicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.

Proteomic profile of human monocytic cells infected with dengue virus

Objective: To identify the changes in the proteome of U937 cells infected with dengue virus (DENV). Methods: In this study, differentiated U937 cultures were infected with two DENV-2 strains, one of which was associated with dengue (DENV-2/NG) and the other one with severe dengue (DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and sepa-rated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity. Results: In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially (five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed (two were downregulated and four were upregu-lated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 kDa protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 kDa protein AA1, tubulin beta, enolase 1, pyruvate kinase, transaldolase and phospholipase C-alpha. Conclusions: Because the monocyte/macrophage lineage is critical for disease patho-genicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.

Molecular association of CD98, CD29, and CD147 critically mediates monocytic U937 cell adhesion

Adhesion events of monocytes represent an important step in inflammatory responses induced by chemokines. The β1-integrin CD29 is a major adhesion molecule regulating leukocyte migration and extravasation. Although several adhesion molecules have been known as regulators of CD29, the molecular interactions between CD29 and its regulatory adhesion molecules (such as CD98 and CD147) have not been fully elucidated. Therefore, in this study, we examined whether these molecules are functionally, biochemically, and cell-biologically associated using monocytic U937 cells treated with aggregation-stimulating and blocking antibodies, as well as enzyme inhibitors. The surface levels of CD29, CD98, and CD147 (but not CD43, CD44, and CD82) were increased. The activation of CD29, CD98, and CD147 by ligation of them with aggregation-activating antibodies triggered the induction of cell-cell adhesion, and sensitivity to various enzyme inhibitors and aggregation-blocking antibodies was similar for CD29-, CD98-, and CD147-induced U937 cell aggregation. Molecular association between these molecules and the actin cytoskeleton was confirmed by confocal microscopy and immunoprecipitation. These results strongly suggest that CD29 might be modulated by its biochemical and cellular regulators, including CD98 and CD147, via the actin cytoskeleton.

Autophagy and apoptosis of acute myelogenous leukemia U937 cell induced by Sirolimus / 中华实用儿科临床杂志

Objective To investigate the autophagy and apoptosis in acute myelogenous leukemia U937 cell induced by Sirolimus.Methods U937 cells were subcultured, and blank control group(normal) and Sirolimus treated groups(12 h, 24 h,48 h) were established.The Sirolimus treated groups were treated by 2 μmol/L concentration of Sirolimus for 12 h,24 h and 48 h, respectively.The cell morphology of U937 cells treated by Sirolimus was observed after 12 h,24 h and 48 h.The survival rate of cells was detected by cell counting kit-8 method.Cell apoptosis was detected by flow cytometry using Annexin V-FITC/PI double labeled.Real-time PCR was used to detect the level of mRNA expression in autophagy specific protein maker mictotubule-associated protein light chain 3 (LC3)-Ⅱ in different treated times by Sirolimus.Sirolimus LC3 protein expression levels after treatment were detected by Western blot method.Results Under inverted microscope, the cell number of Sirolimus treatment group reduced gradually after 12 h ,24 h and 48 h culture, volume of cells became smaller, cells got ruptured, and the nucleus pycnosis and cellular debris increased.With the extension of time, U937 cells survival rate was falling, and there was statistical differences compared with those of the control group(P =0.031).With Sirolimus treatment, U937 cells after 12 h,24 h and 48 h, U937 cell apoptosis rate increased, and there were statistically significances, compared with those of the control group (P =0.027).With Sirolimus treatment U937 cells after 12 h,24 h and 48 h,LC3-Ⅱ mRNA expression and protein expression were down-regulated compared with those of the control group, and there were statistically significances (P =0.029).Conclusions Sirolimus can induce autophagy and apoptosis in U937 cells.Autophagy protein LC3-Ⅱ in gene and protein expression levels were lowered, and LC3-Ⅱ may play an important role in regulating the leukemia cell autophagy.

Regulation of Dickkopf (DKK1) on apoptosis of U937 cell / 中国药学杂志

OBJECTIVE: To explore the regulation of Dickkopf (DKK1) on apoptosis of human acute leukemia U937 cell. METHODS: The reactive oxygen species (ROS) was assessed with DCFH-DA fluorescence probe; the mitochondria membrane potential was assessed with JC-1 staining method, apoptosis rate was detected by AnnexinV-FITC/PI double staining, Western-blot was used to analyse the expression of related protein. RESULTS: Dickkopf can rise the ROS and reduce the mitochondria membrane potential, meanwhile up-regulate the expressing of BAX, down-regulating expressing of Mcl-1 and Bcl-2. CONCLUSION: Dickkopf can promote apoptosis of human acute leukemia U937 cell.

Ursolic acid induces U937 cells differentiation by PI3K/Akt pathway activation / 中国天然药物

AIM@#Ursolic acid (UA), a pentacyclic triterpenoid, is used as an anti-inflammatory and anti-cancer agent. There were few studies on the effects of UA on differentiation, and this is the first time to elucidate the potential effect and molecular mechanism of UA on inducing differentiation in the human leukemia cell line U937.@*METHODS@#Wright-Giemsa staining, nitroblue tetrazolium reduction assay and flow cytometric analysis were utilized to demonstrate the differentiation of U937 cells induced by UA. Western blotting and immunofluorescence assay were used to investigate the possible mechanism.@*RESULTS@#It was found that UA could induce the differentiation of U937cells and Akt-activity was significantly increased during differentiation. Additionally, LY294002, a PI3K-Akt inhibitor, could block the differentiation of U937 cells induced by UA.@*CONCLUSION@#UA could induce the differentiation of U937 cells by activating the PI3K/Akt pathway, and it could be a potential candidate as a differentiation-inducing agent for the therapy of leukemia.