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Monocytic THP-1 Cells (monocytic + thp-1_cell)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Fatty acids as metabolic mediators in innate immunity

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2009
A. Kopp
Abstract Background, Increasing data support the hypothesis of a local and systemic crosstalk between adipocytes and monocytes mediated by fatty acids. The aim of this study was to characterize the immunomodulatory effects of a large panel of fatty acids on cytokines and chemokines in monocytic THP-1 cells and primary human monocytes. We tested whether anti-inflammatory fatty acids are able to inhibit the binding of lipopolysaccharide (LPS) to its receptor, toll-like receptor/MD-2 (TLR4/MD-2). Materials and methods, Resistin, monocyte chemoattractant protein-1 (MCP-1) and tumour necrosis factor (TNF) were measured by enzyme-linked immunosorbent assay. Proteins were analysed by Western blot. A designed Flag-tagged TLR4/MD-2 fusion protein (LPS trap) was used to investigate the effect of fatty acids on binding of LPS to its receptor. In 30 patients with type 2 diabetes mellitus (T2D), the correlation of serum triglyceride levels with LPS-induced monocyte activation was analysed. Results, Eleven fatty acids investigated exerted differential effects on the monocytic release of cytokines and chemokines. Eicosapentaenoic acid had potent anti-inflammatory effects on human primary monocytes and THP-1 cells; 100 and 200 ,M eicosapentaenoic acid dose-dependently inhibited LPS binding to the LPS trap. LPS-induced release of monocytic MCP-1 and TNF was significantly and positively correlated with serum triglyceride levels in 30 patients with T2D. Conclusions, Monocytic activation is differentially regulated by fatty acids and depends on triglyceride levels in T2D. The main finding of the present study shows that eicosapentaenoic acid inhibits the specific binding of LPS to TLR4/MD-2. Eicosapentaenoic acid represents a new anti-inflammatory LPS-antagonist. [source]

7-Ketocholesterol-induced apoptosis

FEBS JOURNAL, Issue 12 2005
Involvement of several pro-apoptotic but also anti-apoptotic calcium-dependent transduction pathways
Oxysterols, and particularly 7-ketocholesterol, appear to be strongly involved in the physiopathology of atherosclerosis. These molecules are suspected to be cytotoxic to the cells of the vascular wall and monocytes/macrophages, particularly by inducing apoptosis. Previous studies have demonstrated that 7-ketocholesterol-induced apoptosis is triggered by a sustained increase of cytosolic-free Ca2+, which elicits the mitochondrial pathway of apoptosis by activation of the calcium-dependent phosphatase calcineurin, leading to dephosphorylation of the ,BH3 only' protein BAD. However, thorough study of the results suggests that other pathways are implicated in 7-ketocholesterol-induced cytotoxicity. In this study, we demonstrate the involvement of two other calcium-dependent pathways during 7-ketocholesterol-induced apoptosis. The activation of the MEK,ERK pathway by the calcium-dependent tyrosine kinase PYK 2, a survival pathway which delays apoptosis as shown by the use of the MEK inhibitor U0126, and a pathway involving another pro-apoptotic BH3 only protein, Bim. Indeed, 7-ketocholesterol treatment of human monocytic THP-1 cells induces the release of Bim-LC8 from the microtubule-associated dynein motor complex, and its association with Bcl-2. Therefore, it appears that 7-ketocholesterol-induced apoptosis is a complex phenomenon resulting from calcium-dependent activation of several pro-apoptotic pathways and also one survival pathway. [source]

Proteome analysis of human monocytic THP-1 cells primed with oxidized low-density lipoproteins

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2006
Jeong Han Kang
Abstract Native low-density lipoprotein (LDL) and oxidized LDL (oxLDL) possess a wide variety of biological properties, and play a central role in atherogenesis. In this study, we used a proteomic analysis of human monocyte THP-1 cells induced with oxLDL or with LDL, to identify proteins potentially involved in atherosclerotic processes. Of the 2500,proteins detected, 93,were differentially expressed as a result of priming with LDL or oxLDL. The proteins were unambiguously identified by comparing the masses of their tryptic peptides with those of all known proteins using MALDI,TOF,MS and the NCBI database. The largest differences in expression were observed for vimentin (94-fold increase), meningioma-expressed antigen,6 (48-fold increase), serine/threonine protein phosphatase,2A (40-fold increase), and beta-1,3-galactosyltransferase (15-fold increase). In contrast, the abundance of an unnamed protein product and phosphogluconate dehydrogenase decreased 30-fold and 25-fold, respectively. The expression of some selected proteins was confirmed by Western blot and RT-PCR analyses. The proteins identified in this study are attractive candidates for further biomarker research. This description of the altered protein profiles induced by oxLDL in human monocytes will support functional studies of the macrophage-derived foam cells involved in the pathogenesis of atherosclerosis. [source]

Development of the method for evaluating protective effect of food factors on THP-1-induced damage to human intestinal Caco-2 monolayers

BIOFACTORS, Issue 1-4 2004
Fumiko Watanabe
Abstract Immune cells located in the intestinal epithelium interact with intestinal epithelial cells via soluble factors. In this study, a new in vitro model using a coculture system was constructed to analyze the interaction between intestinal epithelial cells and macrophage-like cells. Human intestinal epithelial Caco-2 cells were differentiated on semipermeable membranes. Human monocytic THP-1 cells were differentiated to macrophage-like cells and then cocultured on the basolateral side of the Caco-2 cell monolayers. By coculturing for 48 hours, an increased release of lactate dehydrogenase from the Caco-2 cells and a decrease in the transepithelial electrical resistance of the monolayers were observed, suggesting that the coculture with THP-1 induced some disruption of the Caco-2 cells. This disruption was significantly suppressed by adding the anti-TNF-, antibody to the medium, suggesting that TNF-, secreted from THP-1 caused damage to the Caco-2 cells. It is also suggested that this phenomenon is similar to that observed with inflammatory bowel disease (IBD). The effects of food factors on the cells in this coculture system were examined. The disruption of the Caco-2 cell monolayers was significantly reduced by adding caffeine to the medium on the apical side. It is hoped that this coculture system will be a good model for the treatment of IBD. [source]