Search results for "Cell signaling"
showing 10 items of 228 documents
Polyphenols from Pennisetum glaucum grains induce MAP kinase phosphorylation and cell cycle arrest in human osteosarcoma cells
2019
Abstract Osteosarcoma is the most common bone tumor with a high prevalence among children and adolescents. Polyphenols are widely investigated for their chemopreventive and chemotherapeutic proprieties. In the present study, we explored the pro-apoptotic effects of pearl millet, Pennisetum glaucum, phenolic compounds (PGPC) on osteosarcoma U-2OS cells. Our results show that PGPC induced U-2OS cells death, in a dose dependent manner, with an IC50 of 80 μg/mL. Annexin-V and 7-AAD staining show that PGPC induced cell death mainly through caspase-dependent apoptosis as shown by a decrease in cell death when co-treated with pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketon…
General Aspects of Metal Ions as Signaling Agents in Health and Disease
2020
This review focuses on the current knowledge on the involvement of metal ions in signaling processes within the cell, in both physiological and pathological conditions. The first section is devoted to the recent discoveries on magnesium and calcium-dependent signal transduction—the most recognized signaling agents among metals. The following sections then describe signaling pathways where zinc, copper, and iron play a key role. There are many systems in which changes in intra- and extra-cellular zinc and copper concentrations have been linked to important downstream events, especially in nervous signal transduction. Iron signaling is mostly related with its homeostasis. However, it is also …
Oxidative Stress and Vascular Dysfunction in the Retina: Therapeutic Strategies
2020
Many retinal diseases, such as diabetic retinopathy, glaucoma, and age-related macular (AMD) degeneration, are associated with elevated reactive oxygen species (ROS) levels. ROS are important intracellular signaling molecules that regulate numerous physiological actions, including vascular reactivity and neuron function. However, excessive ROS formation has been linked to vascular endothelial dysfunction, neuron degeneration, and inflammation in the retina. ROS can directly modify cellular molecules and impair their function. Moreover, ROS can stimulate the production of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) causing inflammation and cel…
Tissue factor at the crossroad of coagulation and cell signaling
2018
The tissue factor (TF) pathway plays a central role in hemostasis and thrombo-inflammatory diseases. Although structure-function relationships of the TF initiation complex are elucidated, new facets of the dynamic regulation of TF?s activities on cells continue to emerge. Cellular pathways that render TF non-coagulant participate in signaling of distinct TF complexes with associated proteases through the protease-activated receptor (PAR) family of G-protein coupled receptors. Additional coreceptors, including the endothelial protein C receptor (EPCR) and integrins, confer signaling specificity by directing subcellular localization and trafficking. We here review how TF is switchedbetween it…
Direct estrogen receptor (ER) / HER family crosstalk mediating sensitivity to lumretuzumab and pertuzumab in ER+ breast cancer.
2017
Bidirectional cross talk between members of the human epidermal growth factor family of receptors (HER) and the estrogen receptor (ER) is believed to underlie resistance mechanisms that develop in response to treatment with anti-HER agents and endocrine therapy. We investigated the interaction between HER2, HER3 and the ER in vitro using human embryonic kidney cells transfected with human HER2, HER3, and ERα. We also investigated the additive efficacy of combination regimens consisting of anti-HER3 (lumretuzumab), anti-HER2 (pertuzumab), and endocrine (fulvestrant) therapy in vivo. Our data show that both HER2 and HER3 can directly complex with the ER and can mediate phosphorylation of the …
EphrinB2 repression through ZEB2 mediates tumour invasion and anti-angiogenic resistance.
2016
Diffuse invasion of the surrounding brain parenchyma is a major obstacle in the treatment of gliomas with various therapeutics, including anti-angiogenic agents. Here we identify the epi-/genetic and microenvironmental downregulation of ephrinB2 as a crucial step that promotes tumour invasion by abrogation of repulsive signals. We demonstrate that ephrinB2 is downregulated in human gliomas as a consequence of promoter hypermethylation and gene deletion. Consistently, genetic deletion of ephrinB2 in a murine high-grade glioma model increases invasion. Importantly, ephrinB2 gene silencing is complemented by a hypoxia-induced transcriptional repression. Mechanistically, hypoxia-inducible facto…
Food Sensation Modulates Locomotion by Dopamine and Neuropeptide Signaling in a Distributed Neuronal Network
2018
Finding food and remaining at a food source are crucial survival strategies. We show how neural circuits and signaling molecules regulate these food-related behaviors in Caenorhabditis elegans. In the absence of food, AVK interneurons release FLP-1 neuropeptides that inhibit motorneurons to regulate body posture and velocity, thereby promoting dispersal. Conversely, AVK photoinhibition promoted dwelling behavior. We identified FLP-1 receptors required for these effects in distinct motoneurons. The DVA interneuron antagonizes signaling from AVK by releasing cholecystokinin-like neuropeptides that potentiate cholinergic neurons, in response to dopaminergic neurons that sense food. Dopamine al…
MYC Induces a Hybrid Energetics Program Early in Cell Reprogramming
2018
Summary Cell reprogramming is thought to be associated with a full metabolic switch from an oxidative- to a glycolytic-based metabolism. However, neither the dynamics nor the factors controlling this metabolic switch are fully understood. By using cellular, biochemical, protein array, metabolomic, and respirometry analyses, we found that c-MYC establishes a robust bivalent energetics program early in cell reprogramming. Cells prone to undergo reprogramming exhibit high mitochondrial membrane potential and display a hybrid metabolism. We conclude that MYC proteins orchestrate a rewiring of somatic cell metabolism early in cell reprogramming, whereby somatic cells acquire the phenotypic plast…
A novel 3D heterotypic spheroid model for studying extracellular vesicle-mediated tumour and immune cell communication
2017
Cancer-derived extracellular vesicles (EVs) have emerged as important mediators of tumour-host interactions, and they have been shown to exert various functional effects in immune cells. In most of the studies on human immune cells, EVs have been isolated from cancer cell culture medium or patients' body fluids and added to the immune cell cultures. In such a setting, the physiological relevance of the chosen EV concentration is unknown and the EV isolation method and the timing of EV administration may bias the results. In the current study we aimed to develop an experimental cell culture model to study EV-mediated effects in human T and B cells at conditions mimicking the tumour microenvi…
CNS-localized myeloid cells capture living invading T cells during neuroinflammation
2020
Using an in vivo real-time approach, the authors show that local myeloid cells remove early CNS-invading T cells via an engulfment pathway that is dependent on N-acetyl-D-glucosamine (GlcNAc) and lectin. These results reveal a novel capacity of myeloid cells to counteract neuroinflammation.