Search results for "tumor necrosis factor alpha"
showing 10 items of 479 documents
Hop-derived fraction rich in beta acids and prenylflavonoids regulates the inflammatory response in dendritic cells differently from quercetin: unvei…
2021
Dendritic cells (DCs) represent a heterogeneous family of immune cells that link innate and adaptive immunity and their activation is linked to metabolic changes that are essential to support their activity and function. Hence, targeting the metabolism of DCs represents an opportunity to modify the inflammatory and immune response. Among the natural matrices, Humulus lupulus (Hop) compounds have recently been shown to exhibit immunomodulatory and anti-inflammatory activity. This study aimed to evaluate the ability of specific Hop fractions to modulate DCs metabolism after stimulation with lipopolysaccharide (LPS) by an untargeted metabolomics approach and compare their effect with flavonol …
Anti-inflammatory activity of berenjenol and related compounds.
2008
Berenjenol ( 1), isolated from OXANDRA cf. XYLOPIOIDES (Annonaceae), was tested on two different experimental models of inflammation. The compound showed anti-inflammatory activity in the test of acute mouse ear edema induced by TPA (54 % inhibition, 1 μmol/ear) as well as in the test of subchronic inflammation induced by repeated application of TPA (57 % inhibition, 7 × 1 μmol/ear). Moreover, while it reduced the expression of both COX-2 (65 % inhibition at 50 μM) and iNOS (80 % inhibition at 50 μM), it was not active against TNF- α and IL-1 β in murine macrophages (RAW 264.7) stimulated with LPS. Structural modification of 1 gave two derivatives, berenjenol acetate ( 2) and 3-oxo-berenjen…
Stimulation of monokine production by lipoteichoic acids
1991
Lipoteichoic acids (LTAs) isolated from bacterial species, including Staphylococcus aureus, Streptococcus pyogenes A, Enterococcus faecalis, Streptococcus pneumoniae, and Listeria monocytogenes, were tested for their ability to stimulate the production of interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha in cultured human monocytes. LTAs from S. aureus and S. pneumoniae failed to induce monokine production when applied in the concentration range of 0.05 to 5.0 micrograms/ml. However, LTAs from several enterococcal species (0.5 to 5 micrograms/ml) induced the release of all three monokines at levels similar to those observed after lipopolysaccharide stimulation. The kinet…
Dual anti-oxidant and anti-inflammatory actions of the electrophilic cyclooxygenase-2-derived 17-oxo-DHA in lipopolysaccharide- and cigarette smoke-i…
2014
Abstract Background 17-Oxo-DHA is an endogenous electrophilic derivative of the omega-3 fatty acid docosahexaenoic acid (DHA) which is generated in activated macrophages by the action of cyclooxygenase-2. Methods The ability of 17-oxo-DHA to control inflammation and oxidative stress was tested in human macrophages (THP-1) and bronchial epithelial cell line (16HBE) stimulated with cigarette smoke extract (CSE) and lipopolysaccharide (LPS). All data were further confirmed using primary bronchial epithelial cells, alveolar macrophages and peripheral blood mononuclear cells. Results 17-Oxo-DHA was a strong inducer of the anti-oxidant response promoting Nrf2 nuclear accumulation, leading to the …
TNFα Primes Polymorphonuclear Leukocytes for an Enhanced Respiratory Burst to a Similar Extent As Bacterial Lipopolysaccharide
1990
We examined whether preincubating polymorphonuclear leukocytes (PMN) with TNF alpha would result in an enhanced respiratory burst upon subsequent stimulation by various agents. Bacterial lipopolysaccharide (LPS), a known primer of PMN, was used as control. We found that both LPS (0.01 to 10.0 microgram/ml) and recombinant TNF alpha (0.001 to 1.0 microgram/ml) act as direct stimulants of PMN as measured by chemiluminescence. Sixty minutes of preincubation of PMN with 1 microgram/ml TNF alpha or 10 micrograms/ml LPS resulted in similar priming for the respiratory burst elicited by opsonized zymosan, phorbol myristate acetate, zymosan, zymosan-activated serum, aggregated immunoglobulin, and f-…
Transcriptional regulation of miR-224 upregulated in human HCCs by NFκB inflammatory pathways
2012
Background & Aims: miR-224 is up-regulated in human HCCs as compared to both paired peri-tumoral cirrhotic tissues and cirrhotic livers without HCC. Here, we have cloned the miR-224 regulatory region and characterized its transcriptional regulation by the NFκB-dependent inflammatory pathways. Methods: Mature miRNA expression was evaluated by a 2 step stem-loop real-time RT-PCR. The recruitment of polymerase II and transcription factors on the pre-miR-224 promoter has been assessed by ChIPSeq and ChIP. Results: We found miR-224 levels strongly up-regulated in both peri-tumoral cirrhotic livers and HCC samples as compared to normal livers. In silico analysis of the putative miR-224 promoter r…
HSP60 and CpG-DNA-oligonucleotides differentially regulate LPS-tolerance of hepatic Kupffer cells
2004
Background/aims: Hepatic Kupffer cells (KC) are major regulators of the immune response to gut-derived bacterial products; uncontrolled activation of KC by bacterial components is of pathogenic relevance in alcoholic hepatitis and septic shock. Methods: We examined the role of bacterial lipopolysaccharide (LPS), bacterial and autologous HSP60 and bacterial DNA, which are recognized by innate Toll-like receptors, during activation of murine KC. Results: In cultivated KC, autologous HSP60 induced a state of LPS-hyporesponsiveness; bacterial DNA did not mitigate the response to subsequent LPS-challenge in vitro; in contrast, pre-treatment of mice with bacterial DNA even significantly increased…
Nitric oxide synthase activity is inducible in rat, but not rabbit alveolar macrophages, with a concomitant reduction in arginase activity
1995
Alveolar macrophages were obtained by broncho-alveolar lavage of isolated rat and rabbit lungs and cultured (2.5 × 106 cells/dish) for 18 h in the absence or presence of bacterial lipopolysaccharides (LPS) alone or in combination with cytokines. Thereafter, accumulation of 3H-citrulline (NO synthase activity) and 3H-ornithine (arginase activity) were determined. During incubation of rat alveolar macrophages with 3H-arginine clear amounts of 3H-citrulline and 3H-ornithine (3.8 and 4.6% of the added 3H-arginine, respectively) were formed and most of these metabolites appeared in the incubation medium (ratios extra-/intracellular of 17 and 70 for 3H-citrulline and 3H-ornithine, respectively). …
Whole blood endotoxin responsiveness in patients with chronic heart failure: the importance of serum lipoproteins.
2005
Background Endotoxin [lipopolysaccharide (LPS)] may be an important stimulus for cytokine release in patients with chronic heart failure (CHF). We sought to investigate the relationship between whole blood endotoxin responsiveness and serum lipoprotein concentrations. It is not known if low-dose LPS is sufficient to stimulate immune activation. Methods and results Whole blood from 32 CHF patients (mean age 66±2 years, NYHA class 2.7±0.2, five female) and 11 healthy control subjects (mean age 47±4 years, six female) was stimulated with LPS at nine different concentrations (0.001 to 10 ng/mL), and tumor necrosis factor (TNF-α) release was quantified. Reference standard endotoxin at concentrat…
Modulation of Forssman Glycosphingolipid Expression by Murine Macrophages: Coinduction with Class II MHC Antigen by the Lymphokines IL4 and IL6
1990
In contrast to murine spleen M phi, resident peritoneal M phi from health mice express very little Forssman glycolipid antigen (Fo). The following experiments suggest that Fo expression by peritoneal M phi may be associated with inflammation. Balb/c and CBA/J mice were given inflammatory stimuli by i.p. injection of live BCG, thioglycollate (TG), Corynebacterium parvum (CP), proteose peptone (PP), or LPS. Control animals received pyrogen-free saline. Expression of Fo and Ia antigen by peritoneal M phi was determined by immunofluorescence after 4 d. Application of TG or CP led to an up to 30-fold increase in Fo+, Ia+ double positive M phi over that in control animals. LPS caused mainly an in…