Search results for "Signal Transduction"
showing 10 items of 2020 documents
Cadmium as a transcriptional modulator in human cells
2010
Cadmium (Cd) is an underground mineral widely used in the steel industry, in plastics, and as a component of batteries. It is an industrial and environmental pollutant released as an air contaminant from fertilizers and, more prominently, in the form of wastewater. Food, drinking water, and, mainly, inhalation of smoke from cigarettes are sources of daily exposure of humans to the heavy metal. Although Cd has no known useful function for humans as well as other organisms, it appears to evoke in cells a number of responses that involve not only death signaling but also protective reactions against the toxicity. This finding prompted a number of experimental studies aimed to elucidate the cel…
A differential role of CREB phosphorylation in cAMP-inducible gene expression in the rat pineal
2000
In the rat pineal gland cAMP mediates nocturnal induction of the enzyme arylalkylamine N-acetyltransferase (AA-NAT) as well as of transcription factors such as inducible cAMP early repressor (ICER), Fos-related antigen-2 (Fra-2) and JunB. Cyclic AMP stimulates the phosphorylation of the DNA binding protein cAMP response element binding protein (CREB). While cAMP-induced CREB phosphorylation appears to be a prerequisite for AA-NAT and ICER gene expression, it is not known whether CREB phosphorylation accounts for the full cAMP response of the two genes. Furthermore, the significance of CREB phosphorylation in cAMP-activated Fra-2 and JunB transcription is unknown. In the present in vitro stu…
Interactions between cholinergic and fibroblast growth factor receptors in brain trophism and plasticity
2014
Acetylcholine, acting on both nicotinic receptors (nAChRs) and muscarinic receptors (mAChRs), plays a role in the regulation of synaptic plasticity, being involved in the regulation of cellular processes and cognitive functions, such as learning, memory and attention. Recently, G protein coupled receptors (GPCRs), including mAChRs, have been reported to transactivate tyrosine-kinase receptors (RTK), such as epidermal growth factor receptor (EGFR), and initiate their intracellular signaling. In this minireview we have first analysed the RTK transactivation mechanisms, involving cholinergic receptors, and thereafter the interplay between AChR and neurotrophic factor systems built up by FGF2 a…
Receptors Linked to Hydrolysis of Choline Phospholipids: the Role of Phospholipase D in a Putative Mechanism of Signal Transduction
1990
The structure and basic functions of biomembranes are essentially determined by the lipid bilayer. In contrast, specific membrane functions, such as signal recognition and transduction and transport processes, have been preferentially attributed to proteins that are embedded in the outer or inner leaflet of this bilayer or may span the membrane up to five times or more, as in the case of receptor molecules. The segregating view of membrane protein and lipid functions may have delayed a broad research interest in the dynamic interactions between these components of the membrane. The present review is devoted to such a recently discovered interaction: the coupling of receptor activation and h…
Dendritic cell-derived IL-12p40 homodimer contributes to susceptibility in cutaneous leishmaniasis in BALB/c mice
2007
Abstract Protection against Leishmania major in resistant C57BL/6 mice is mediated by Th1 cells, whereas susceptibility in BALB/c mice is the result of Th2 development. IL-12 release by L. major-infected dendritic cells (DC) is critically involved in differentiation of Th1 cells. Previously, we reported that strain differences in the production of DC-derived factors, e.g., IL-1αβ, are in part responsible for disparate disease outcome. In the present study, we analyzed the release of IL-12 from DC in more detail. Stimulated DC from C57BL/6 and BALB/c mice released comparable amounts of IL-12p40 and p70. In the absence of IL-4, BALB/c DC produced significantly more IL-12p40 than C57BL/6 DC. D…
Astrocytes in culture express the full-length Trk-B receptor and respond to brain derived neurotrophic factor by changing intracellular calcium level…
2000
Abstract Although cultured astroglial cells were reported to express exclusively the truncated non-catalytic Trk B receptor for brain-derived neurotrophic factor (BDNF), we detect here, using a sensitive ribonuclease protection assay, mRNAs for both truncated (TrkB–T) and the full length catalytic (TrkB–fl) form of BDNF receptor in developing cortical astrocytes and neurons in culture. Cortical neurons and immature astroglia, such as radial glia and proliferating astrocytes, express both the protein and mRNAs for TrkB-fl and TrkB-T, whereas the differentiation of astrocytes leads to a decrease in the trkB-fl mRNA, being the truncated TrkB the predominant receptor in differentiating and conf…
Damping excessive inflammation and tissue damage in Mycobacterium tuberculosis infection by Toll IL-1 receptor 8/single Ig IL-1-related receptor, a n…
2007
Abstract Toll IL-1R 8/single Ig IL-1-related receptor (TIR8/SIGIRR) is a member of the IL-1R family, expressed by epithelial tissues and immature dendritic cells, and is regarded as a negative regulator of TLR/IL-1R signaling. Tir8-deficient mice were rapidly killed by intranasal administration of low doses of Mycobacterium tuberculosis, despite controlling efficiently the number of viable bacilli in different organs. Tir8−/−-infected mice showed an increased number of neutrophils and macrophages in the lungs; however, mycobacteria-specific CD4 and CD8 T cells were similar in Tir8−/− and Tir8+/+ mice. Exaggerated mortality of Tir8−/− mice was due to massive liver necrosis and was accompanie…
Mycobacterium tuberculosis secretory proteins downregulate T cell activation by interfering with proximal and downstream T cell signalling events
2015
Background Mycobacterium tuberculosis (M. tuberculosis) modulates host immune response, mainly T cell responses for its own survival leading to disease or latent infection. The molecules and mechanisms utilized to accomplish immune subversion by M. tuberculosis are not fully understood. Understanding the molecular mechanism of T cell response to M. tuberculosis is important for development of efficacious vaccine against TB. Methods Here, we investigated effect of M. tuberculosis antigens Ag85A and ESAT-6 on T cell signalling events in CD3/CD28 induced Peripheral blood mononuclear cells (PBMCs) of PPD+ve healthy individuals and pulmonary TB patients. We studied CD3 induced intracellular calc…
A helicopter perspective on TB biomarkers: pathway and process based analysis of gene expression data provides new insight into TB pathogenesis.
2013
Biomarker host genetic signatures are considered key tools for improved early diagnosis of tuberculosis (TB) disease (development). The analysis of gene expression changes based on a limited number of genes or single study designs, however, may not be sufficient for the identification of universal diagnostic biomarker profiles. Here we propose that biological pathway and process based analyses from multiple data sets may be more relevant for identification of key pathways in TB pathogenesis, and may reveal novel candidate diagnostic TB biomarkers. A number of independent genome-wide gene expression studies have recently been performed to study expression of biomarkers for TB disease. We hav…
Acidic Environment Leads to ROS-Induced MAPK Signaling in Cancer Cells
2011
Tumor micromilieu often shows pronounced acidosis forcing cells to adapt their phenotype towards enhanced tumorigenesis induced by altered cellular signalling and transcriptional regulation. In the presents study mechanisms and potential consequences of the crosstalk between extra- and intracellular pH (pH(e), pH(i)) and mitogen-activated-protein-kinases (ERK1/2, p38) was analyzed. Data were obtained mainly in AT1 R-3327 prostate carcinoma cells, but the principle importance was confirmed in 5 other cell types. Extracellular acidosis leads to a rapid and sustained decrease of pH(i) in parallel to p38 phosphorylation in all cell types and to ERK1/2 phosphorylation in 3 of 6 cell types. Furth…