Search results for "Signaling"

Physiology and cell biology of the endothelium: a dynamic interface for cell communication.

1997

This manuscript presents a brief overview of the physiology and cell biology of the endothelium, which is the basis for understanding the role of endothelial cells in pathological processes as diverse as atherosclerosis, tumour intravasation and multiple organ failure. Following consideration of general aspects of endothelial function in regulating haemostasis, vascular tone and growth, special emphasis will be placed on endothelial regulation of the inflammatory response, which centres on the microcirculation. A particular role in inflammation is played by cell adhesion molecules (CAM), expressed both on endothelial and blood cells. Cell and molecular biological methods to investigate the …

P043 Succinate receptor (SUCNR1) mediates leukocyte-endothelial cell interactions induced by TNFa

2021

Abstract Background The Krebs cycle metabolite succinate contributes to inflammatory conditions like arthritis and colitis by activating its receptor SUCNR1. We aimed to analyze whether the succinate-SUCNR1 pathway contributes to the leukocyte-endothelial cell interactions that initiate the inflammatory response. Methods We evaluated leukocyte rolling and adhesion by intravital microscopy in cremaster venules of wild-type (WT) and Sucrn1−/− mice treated, 4h before, with succinate (1 Mm, intraescrotally), combined or not with the common pro-inflammatory cytokine TNFα (500 ng/mice, i.p.), or with their vehicles. We analyzed the activity of the NF-κB signaling pathway in endothelial cells (HUV…

Gènes fongiques liés au calcium impliqués dans la mycorhize à arbuscules

2012

Fluctuations in intracellular (Ca2+) calcium levels generate signaling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant cell responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary meesenger in the fungal symbiont. The molecular basis of fungal calcium homeostasis in the AM symbiosis was analyzed by investigating the expression of Ca2+-related fungal genes. In a first study, G. mosseae genes putatively encoding a MAP3k-like protein kinase (Gm2) and a P-type ATPase (Gm152) were investigated. Both Ca2+-related genes were up-regulated by A. sinicum root exudates, sugges…

Growth control in mammalian cells by cell-cell contacts.

1990

Growth of normal diploid mammalian cells in vitro is strongly regulated by the actual cell density. Cell-cell contacts via specific plasma membrane glycoproteins whose glycan moieties interact with specific receptors has been found to be a main growth regulatory principle. Malignant growth is suggested to result from impaired function of these receptors.

Sub-lethal doses of polybrominated diphenyl ethers affect some biomarkers involved in energy balance and cell cycle, via oxidative stress in the mari…

2019

Abstract Polybrominated diphenyl ethers (PBDEs) are a class of persistent contaminants which are found all over the world in the marine environment. Sparus aurata fibroblast cell line (SAF-1) was exposed to increasing concentrations of PBDEs 47 and 99, until 72 h to evaluate the cytotoxicity, reactive oxygen species (ROS) production and the expression of some selected molecular markers related to cell cycle, cell signaling, energetic balance and oxidative stress (p53, erk-1, hif-1α and nrf-2), by real-time PCR. Furthermore, SAF-1 cells were exposed for 7 and 15 days to sub-lethal concentrations, in order to evaluate the response of some biomarkers by immunoblotting (p53, ERK-1, AMPK, HIF-1α…

Effects of Zizyphus lotus L. (Desf.) polyphenols on Jurkat cell signaling and proliferation.

2013

We assessed the effects of Zizyphus lotus L. (Desf.) polyphenols (ZLP) on T-cell signaling and proliferation. Our results showed that ZLP exerted no effect on the increases in intracellular free calcium concentrations, [Ca(2+)]i, in human Jurkat T-cells. However, ZLP modulated the thapsigargin-induced increases in [Ca(2+)]i in these cells. ZLP treatment was found to decrease the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). In addition, ZLP induced a rapid (t1/2=33s) and dose-dependent decrease in intracellular pH (pHi) in human Jurkat T-cells. Furthermore, ZLP significantly curtailed T-cell proliferation by diminishing their progression from S to G2/M phase of cell…

Estrogen-induced cell signalling in a cellular model of Alzheimer's disease.

2003

Alzheimer's disease (AD) is characterised by deposition of a 4 kDa amyloid-beta peptide (Abeta) into senile plaques of the affected brain. Abeta is a proteolytic product of the membrane protein, amyloid precursor protein (APP). An alternative cleavage pathway involves alpha-secretase activity and results in secretion of a 100 kDa non-amyloidogenic APP (sAPPalpha) and therefore a potential reduction in Abeta secretion. We have shown that estrogen induces alpha-cleavage and therefore results in the secretion of sAPPalpha. This secretion is signalled via MAP-kinase and PI-3 kinase signal-transduction pathways. These pathways also have the potential to inhibit the activation of glycogen synthas…

Oxidative stress resistance in hippocampal cells is associated with altered membrane fluidity and enhanced nonamyloidogenic cleavage of endogenous am…

2010

Reactive oxygen species (ROS) have important roles as signaling molecules in the regulation of a variety of biological processes. On the other hand, chronic oxidative stress exerted by ROS is widely considered a causative factor in aging. Therefore, cells need to be able to adapt to a chronic oxidative challenge and do so to a certain cell-type-specific extent. Recently, we have shown in oxidative-stress-resistant cell lines, HT22(H2O2) and HT22(Glu), derived from the neuronal cell line HT22 by chronic exposure to sublethal concentrations of H(2)O(2) and glutamate, that, in addition to the known antioxidant defense mechanisms, e.g., activation of antioxidant enzymes or up-regulation of heat…

2013

In multiple sclerosis (MS) autoaggressive T effector cells (Teff) are not efficiently controlled by regulatory T cells (Treg) but the underlying mechanisms are incompletely understood. Proinflammatory cytokines are key factors facilitating Teff activity in chronic inflammation. Here we investigated the influence of IL-6 on Treg sensitivity of Teff from therapy-naive MS patients with or without active disease. Compared to healthy volunteers and independent of disease course CD4+ and especially CD8+ MS-Teff were insensitive against functional active Treg from healthy controls. This unresponsiveness was caused by accelerated production of IL-6, elevated IL-6 receptor expression and phosphoryla…

Distinct Signaling Cascades of TREM-1, TLR and NLR in Neutrophils and Monocytic Cells

2013

Triggering receptor expressed on myeloid cells 1 (TREM-1) is an important mediator of innate inflammatory responses in microbial infections and sepsis. TREM-1 ligation on neutrophils (PMN) or monocytes results in the production of proinflammatory cytokines. Engagement of TREM-1 induces the activation of MAP kinases as well as rapid Ca<sup>2+</sup> mobilization. However, a detailed understanding of TREM-1 signaling pathways is currently lacking. We evaluated the TREM-1 signaling hierarchy in monocytic cells and found that the acute myeloid leukemia cell line MUTZ-3 expresses TREM-1 in a natural and functional manner. We compared essential signaling molecules of the TREM-1, TLR an…