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Nontoxic RsDPLA As a Potent Antagonist of Toxic Lipopolysaccharide
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Nilofer Qureshi, Bruce W. Jarvis, Kuni Takayama
Spl is an important transcription factor involved in the regulation of expression of membrane CD14 (62). CD 14 upregulation in the process of monocyte-specific differentiation induced by vitamin D3 occurs mainly at the level of gene transcription. This induction requires new protein synthesis. Using stable transfection of the monocytoid U937 cell line with a series of deletion mutants of the CD 145’ upstream sequence coupled to a reporter gene construct, Zhang et al. (62) showed that bp−128 to −70 is the critical region for the induction of CD14 expression. Moreover Spl-binding sites are present in the promoter regions of a number of LPS-inducible genes (62–67), although promoter analysis demonstrating the requirement for Spl in the induction of these genes by LPS has not been demonstrated. In addition to mediating tissue-specific expression, Spl plays a critical role in this induction. Spl binding sites are also present in multiple monocytic specific genes such as CD lib (64) and the M-CSF receptor promoter (65). Spl plays a critical role in tissue-specific promoter activity of monocyte genes.
Steroids and Infection
Published in Herman Friedman, Thomas W. Klein, Andrea L. Friedman, Psychoneuroimmunology, Stress, and Infection, 2020
Yoshimasa Yamamoto, Herman Friedman
The reduced number of circulating monocytes, especially those bearing the Fc receptor, in the blood of a patient due to the administration of steroids has been widely recognized.76–79In vivo findings are supported by the in vitro study showing that hydrocortisone inhibits macrophage production in murine granulocyte-macrophage precursor cell (CFU-GM) cultures.80 Inhibition of macrophage differentiation by steroids, demonstrated by use of the human monocytic cell line U937 to study the effect of cortisol on cellular differentiation to macrophages,81 might also account for the reduced number of circulating monocytes.
Active Specific Immunization by the Use of Leukemic Dendritic Cell Vaccines
Published in Gertjan J. L. Kaspers, Bertrand Coiffier, Michael C. Heinrich, Elihu Estey, Innovative Leukemia and Lymphoma Therapy, 2019
Ilse Houtenbos, Gert J. Ossenkoppele, Arjan A. van de Loosdrecht
One mechanism by which tumors could potentially escape elimination by the immune system is by secretion of cytokines that suppress cells involved in immune surveillance (52,53). The production of factors such as vascular endothelial growth factor (VEGF), IL-6, M-CSF, IL-10, and TGFβ are associated with inhibited DC function and maturation (54,55). It was shown that the U937 leukemic cell line generates tumor supernatant that inhibits antigen presentation and subsequent T-cell secretion of IFNγ and IL-2 (56).
Effect of erythromycin on the ultrastructure of human macrophages exposed to cigarette smoke extract in vitro
Published in Ultrastructural Pathology, 2022
Shaoshuang Wang, Jianjun Huo, Yanlin Wei, Mei Huan, Zhouling Luo, Meihua Li, Mingzhi Wen, Xiaoning Zhong, Zhiyi He, Nan Ma, Jufeng Qiu, Xiaojuan Tang
Human macrophages were obtained via the differentiation of U937 human monocytic cells.18,19 U937 cells, purchased from the American Type Culture Collection (CRL-1593.2), were seeded at a density of 1–2 × 106 cells/well in 6-well culture plate and grown in RPMI 1640 medium (Thermo Fisher Scientific, Inc.) supplemented with 10% FBS (GE Healthcare), 2 mM L-glutamine, 100 µg/ml penicillin, 100 U/ml streptomycin, 1% nonessential amino acids, 1% sodium pyruvate, 1 µg/ml human holotransferrin, and 1 mM oxaloacetic acid, and cells were cultured at 37°C in a humidified atmosphere containing 5% CO2. According to standard procedures, the U937 cells were induced to differentiate with overnight using 10 ng/ml phorbol 12-myristate 13-acetate (Omnilabo International) overnight.20 Light microscopy was used to evaluate the status of differentiation or adhesion.
GC-MS Profiling and Antineoplastic Activity of Pelargonium Inquinans Ait Leaves on Acute Leukaemia Cell Lines U937 and Jurkat
Published in Nutrition and Cancer, 2022
Ogochukwu Izuegbuna, Gloria A. Otunola, Graeme Bradley
The cytotoxic effect of P. inquinans leaf extracts on RAW 264.7 macrophages cells was determined by MTT (3-(4, 5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. In addition, the cytotoxic effect of P. inquinans extracts was also examined in the acute leukemia cancer cell lines U937 and Jurkat. Fresh and dried plant extracts of the various solvents (aqueous, acetone & ethanol) were weighed and dissolved in dimethyl sulfoxide (DMSO). They were then all sonicated for proper solubilization and stored at −20 °C. The U937 and Jurkat cell lines were plated at a density of 2.5 × 104 cells/well in a 96-well plate and cultured overnight in an incubator at 37 °C. After 24 h the plant extracts were added at various concentrations (12.5,25,50, 100, and 200 μg/ml for U937; 25,50, 100 and 200 μg/ml for Jurkat), then the cells were incubated for another 48 h. One hundred microliters (100 μl) of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide added to each well and incubated at room temperature for 1 h. The cell viability was measured at an optical density of 560 nm in a microplate reader (Multiscan MS, Labsystems). All tests were done in triplicates.
Encapsulation of S-nitrosoglutathione: a transcriptomic validation
Published in Drug Development and Industrial Pharmacy, 2019
Ramia Safar, Rémi Houlgatte, Alain Le Faou, Carole Ronzani, Wen Wu, Luc Ferrari, Hélène Dubois-Pot-Schneider, Bertrand H. Rihn, Olivier Joubert
The release of encapsulated GSNO is slow until 18 h [16] and “GNP50_24” exposed cells display upregulation of genes involved in cell cycle, cytoskeleton and chromosome organizations. This effect is likely due to GSNO given that it is also observed following a 4-h exposure to free GSNO. Using U937 cells, Cui et al. (2005) already demonstrated that 400 µM of GSNO induced genes involved in cell cycle, in particular, in G1/S transition, which is in agreement with our own results [39]. In addition, PTEN pathway, that regulates signaling pathways involved in cell growth and apoptosis, was inhibited after a 24-h exposure period in “GNP”. This may be due to the nitrosation of PTEN by GSNO as proposed by Carver et al. [40]. Thus, the encapsulation of a low dose of GSNO ensure the permanence of its effect up to 24 h. However, as pathways corresponding to cell cycle and involving potential oncogenes were identified, in vivo development, if any, should take into account the possibility of an occurence of oncogenic effects as it has been already suggested in vitro [41–43].