scholarly journals Leukotriene B4 stimulates c-fos and c-jun gene transcription and AP-1 binding activity in human monocytes

1992 ◽  
Vol 282 (3) ◽  
pp. 625-629 ◽  
Author(s):  
J Staňková ◽  
M Rola-Pleszczynski
Keyword(s):  
Human Peripheral Blood ◽  
Leukotriene B4 ◽  
Binding Activity ◽  
Dependent Manner ◽  
Blood Monocytes ◽  
Concentration Dependent Manner ◽  
Nuclear Factors ◽  
Oncogene Products ◽  
Kinetics Of

We have examined the effect of leukotriene B4 (LTB4), a potent lipid proinflammatory mediator, on the expression of the proto-oncogenes c-jun and c-fos. In addition, we looked at the modulation of nuclear factors binding specifically to the AP-1 element after LTB4 stimulation. LTB4 increased the expression of the c-fos gene in a time- and concentration-dependent manner. The c-jun mRNA, which is constitutively expressed in human peripheral-blood monocytes at relatively high levels, was also slightly augmented by LTB4, although to a much lower extent than c-fos. The kinetics of expression of the two genes were also slightly different, with c-fos mRNA reaching a peak at 15 min after stimulation and c-jun at 30 min. Both messages rapidly declined thereafter. Stability of the c-fos and c-jun mRNA was not affected by LTB4, as assessed after actinomycin D treatment. Nuclear transcription studies in vitro showed that LTB4 increased the transcription of the c-fos gene 7-fold and the c-jun gene 1.4-fold. Resting monocytes contained nuclear factors binding to the AP-1 element, but stimulation of monocytes with LTB4 induced greater AP-1-binding activity of nuclear proteins. These results indicate that LTB4 may regulate the production of different cytokines by modulating the yield and/or the function of transcription factors such as AP-1-binding proto-oncogene products.

scholarly journals Effect of Clinoptilolite and Sepiolite Nanoclays on Human and Parasitic Highly Phagocytic Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yanis Toledano-Magaña ◽  
Leticia Flores-Santos ◽  
Georgina Montes de Oca ◽  
Alfonso González-Montiel ◽  
Juan-Pedro Laclette ◽  
...  
Keyword(s):  
Cell Line ◽  
Human Peripheral Blood ◽  
Dependent Manner ◽  
Blood Monocytes ◽  
Phagocytic Cells ◽  
Need To Evaluate ◽  
Potential Applications ◽  
Low Cytotoxicity ◽  
Dose Dependent

Nanoclays have potential applications in biomedicine raising the need to evaluate their toxicity inin vitromodels as a first approach to its biocompatibility. In this study,in vitrotoxicity of clinoptilolite and sepiolite nanoclays (NC) was analyzed in highly phagocytic cultures of amoebas and human and mice macrophages. While amebic viability was significantly affected only by sepiolite NC at concentrations higher than 0.1 mg/mL, the effect on macrophage cultures was dependent on the origin of the cells. Macrophages derived from human peripheral blood monocytes were less affected in viability (25% decrease at 48 h), followed by the RAW 264.7 cell line (40%), and finally, macrophages derived from mice bone marrow monocytes (98%). Moreover, the cell line and mice macrophages die mainly by necrosis, whereas human macrophages exhibit increased apoptosis. Cytokine expression analysis in media of sepiolite NC treated cultures showed a proinflammatory profile (INFγ, IL-1α, IL-8, and IL-6), in contrast with clinoptilolite NC that induced lees cytokines with concomitant production of IL-10. The results show that sepiolite NC is more toxic to amoebas and macrophages than clinoptilolite NC, mostly in a time and dose-dependent manner. However, the effect of sepiolite NC was comparable with talc powder suggesting that both NC have low cytotoxicityin vitro.

Functional Role of Wogonin in Anti-Angiogenesis

2012 ◽  
Vol 40 (02) ◽  
pp. 415-427 ◽  
Author(s):  
Chiu-Mei Lin ◽  
Yen-Hsu Chen ◽  
Jiann-Ruey Ong ◽  
Hon-Ping Ma ◽  
Kou-Gi Shyu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Therapeutic Option ◽  
Suppressive Effect ◽  
Binding Activity ◽  
Janus Kinase ◽  
Dependent Manner ◽  
Vegf Expression ◽  
Concentration Dependent Manner ◽  
Biologically Relevant

Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway occurs commonly in cancer cells and endothelial cells, and contributes to angiogenesis. Wogonin is a compound with many biologically relevant properties. We previously reported that wogonin blocked IL-6-induced angiogenesis through suppression of VEGF expression, an important regulator of angiogenesis. However, the pathway involved in the suppressive effect of wogonin on IL-6-induced VEGF has not been completely clarified. This study aimed to investigate the molecular mechanisms participating in the suppression of wogonin on IL-6-induced VEGF in vitro, focusing on IL-6R/JAK1/STAT3/VEGF pathway. Both STAT3 siRNA and wogonin treatment resulted in an abolition of the expression of VEGF. Moreover, our data revealed that wogonin treatment after STAT3 knock-down did not further suppress VEGF expression. The addition of IL-6R siRNA or wogonin resulted in a decrease in the expression level of the phosphorylated JAK1 protein. Furthermore, wogonin significantly decreased the amount of phosphorylated STAT3. Finally, by EMSA, wogonin suppressed IL-6-induced STAT3 binding activity in a concentration-dependent manner. Taken together, our results show that wogonin suppresses IL-6-induced VEGF by modulating the IL-6R/JAK1/STAT3 signaling pathway. Based on this study, we suggest that wogonin may provide a new potential therapeutic option for treatment of IL-6-related pathological angiogenesis.

scholarly journals In-VitroCarbofuran Induced Genotoxicity in Human Lymphocytes and Its Mitigation by Vitamins C and E

2012 ◽  
Vol 32 (3) ◽  
pp. 153-163 ◽  
Author(s):  
Ratnesh Kumar Sharma ◽  
Bechan Sharma
Keyword(s):  
Dna Damage ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Natural Antioxidants ◽  
Underlying Mechanism ◽  
Positive Control ◽  
Peripheral Blood Lymphocytes ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Various efforts have been made in past in order to predict the underlying mechanism of pesticide-induced toxicity usingin vitroand animal models, however, these predictions may or may not be directly correlated with humans. The present study was designed to investigate the carbofuran induced genotoxicity and its amelioration by vitamins C and E by treating human peripheral blood lymphocytes (PBLs) with different concentrations (0, 0.5, 1.25, 2.5, 3.75 and 5.0 μM) of this compound. The treatment of PBLs with carbofuran displayed significant DNA damage in concentration dependent manner. The carbofuran induced genotoxicity could be ameliorated to considerable extent by pretreatment of PBLs with equimolar (10 μM) concentration of each of the vitamins C and E; the magnitude of protection by vitamin E being higher than by vitamin C. Also, it was found that the level of protection by these vitamins was higher when PBLs were treated with lower concentrations of pesticide. The significant DNA damage as observed by H2O2, a positive control in the present study, and its amelioration by natural antioxidants (vitamins C and E) lend an evidence to suggest that carbofuran would have caused genotoxicity via pesticide induced oxidative stress.

scholarly journals In vitro Cytotoxic and Genotoxic Effects of Methanol and Aqueous Extracts of Gymnosporia Montana Plant

2019 ◽  
pp. 1-11
Author(s):  
Nishat Ansari ◽  
Divya Chandel
Keyword(s):  
Aqueous Extract ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Antioxidant Properties ◽  
In Vitro Cytotoxicity ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Introduction: Gymnosporia montana Benth. is a medicinal herb which has been valued in Ayurvedic medicine for its hepatoprotective effect. The plant has been studied for its pharmacological, antimicrobial, and antioxidant properties, but there are no reports on its genotoxicity. Aim: Hence, in the present study, two extracts of G. montana (70% methanolic and aqueous) at different concentrations were evaluated for the in vitro cytotoxicity and genotoxicity in Human peripheral blood lymphocyte cultures (PBLC) since these are well-established techniques for the analysis of the potentially mutagenic and carcinogenic chemicals. Methodology: The 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT), Mitotic index (MI), Sister-chromatid exchanges (SCEs), Cell cycle proliferative index (CCPI), Average generation time (AGT) and Population doubling time (PDT) were scored in cultures set up from 10 different healthy donors. The treatment of the cell culture was done employing different extracts of G. montana at three concentrations (1.78µg/mL, 3.57µg/mL and 7.14µg/mL) with control and positive control (Ethyl methanesulfonate [EMS (1.93 mM)]). Results: The MTT results showed the cytotoxic effect in a concentration-dependent manner in both the methanol and aqueous extract and the IC50 value of methanol and aqueous extract was found to be 2.63 µg/mL and 3.63 µg/mL respectively.  The MI (p<.001) and CCPI (p<.05) in both the extracts showed significant values at higher concentration, but at lower and mid concentrations both the extracts were non-significant and the total SCEs, AGT and PDT in all the concentrations showed non-significant results when compared with the control. Conclusion: These results indicate that the G. montana plant extracts at lower two concentrations showed no cytotoxicity and genotoxicity effects in cultured human peripheral blood lymphocytes. Therefore, we suggest that the plant extract is safe for use at the lower concentrations in traditional medicine.

L-Gossypol Inhibits NF- κB, Down Regulates Mcl-1 and Induces Apoptosis of Primary Acute Myeloid Leukaemia Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4813-4813
Author(s):  
Chris J Pepper ◽  
Hani Y Osman ◽  
Saman Hewamana ◽  
Elisabeth J Walsby ◽  
Alan K Burnett ◽  
...  
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Conflicts Of Interest ◽  
White Cell Count ◽  
Annexin V ◽  
Binding Activity ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Acute Myeloid

Abstract Abstract 4813 Standard treatments for acute myeloid leukaemia (AML) result in a median survival of approximately 1 year. There is now a realisation that in order to significantly improve outcomes in this disease more targeted therapies that take account of the specific biology of the tumour cell are required. L-Gossypol is a polyphenolic oil cotton seed extract that has anti-tumour activity against a range of haematological malignancies but has never been evaluated in AML cells. It is known to act as a BH3-mimetic, binding to the BH3 pocket of anti-apoptotic proteins and displacing pro-death partners to induce apoptosis. However, knowledge of the molecular events that underpin its downstream effects is limited. In this study we analysed the in vitro effects of L-Gossypol in 50 primary AML samples in order to determine its efficacy and mode of action. Apoptosis was induced in all the samples tested in a dose- and time-dependent manner as evidenced by increased Annexin V / propidium iodide labelling and the activation of caspase-9 and caspase-3. The median LD50 value (the concentration of drug required to kill 50% of the cells) was 27.5μM ± 18.3μM. There was no association between LD50 and age, sex, presenting white cell count, FLT3 mutation status or karyotype. Mechanistically, L-gossypol decreased the DNA binding activity of the NF-κB subunit, Rel A, in a concentration-dependent manner; this inhibition was evident after only 4 hours and preceded the induction of apoptosis. Furthermore, treatment with L-Gossypol inhibited the transcription of the NF-κB-regulated genes CFLAR, BCL2, BIRC5 and MCL1 in the same timeframe. Finally, studies of Mcl-1 protein expression showed down regulation in a dose-dependent manner but this was only apparent after 8 hours exposure to L-Gossypol. Taken together, our data demonstrate that L-Gossypol works, at least in part, through the inhibition of NF-κB and our data provides a rationale for clinical investigations of this agent in AML patients. Disclosures: No relevant conflicts of interest to declare.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

Influence of Brain Gangliosides on the Formation and Properties of Supported Lipid Bilayers for Binding Kinetics Studies

2018 ◽  
Author(s):  
Luke Jordan ◽  
Nathan Wittenberg
Keyword(s):  
Lipid Bilayers ◽  
Binding Kinetics ◽  
Supported Lipid Bilayers ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Supported Lipid Bilayer ◽  
Head Groups ◽  
Lipid Diffusion ◽  
Kinetics Of ◽  
Brain Gangliosides

This is a comprehensive study of the effects of the four major brain gangliosides (GM1, GD1b, GD1a, and GT1b) on the adsorption and rupture of phospholipid vesicles on SiO2 surfaces for the formation of supported lipid bilayer (SLB) membranes. Using quartz crystal microbalance with dissipation monitoring (QCM-D) we show that gangliosides GD1a and GT1b significantly slow the SLB formation process, whereas GM1 and GD1b have smaller effects. This is likely due to the net ganglioside charge as well as the positions of acidic sugar groups on ganglioside glycan head groups. Data is included that shows calcium can accelerate the formation of ganglioside-rich SLBs. Using fluorescence recovery after photobleaching (FRAP) we also show that the presence of gangliosides significantly reduces lipid diffusion coefficients in SLBs in a concentration-dependent manner. Finally, using QCM-D and GD1a-rich SLB membranes we measure the binding kinetics of an anti-GD1a antibody that has similarities to a monoclonal antibody that is a hallmark of a variant of Guillain-Barre syndrome.

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