Search results for "Cell Signaling"

Pantethine Alters Lipid Composition and Cholesterol Content of Membrane Rafts, With Down-Regulation of CXCL12-Induced T Cell Migration

2015

Pantethine, a natural low-molecular-weight thiol, shows broad activity in a large range of essential cellular pathways. It has been long known as a hypolipidemic and hypocholesterolemic agent. We showed recently that it exerts a neuroprotective action in mouse models of cerebral malaria and Parkinson's disease through multiple mechanisms. In the present study we looked at its effects on membrane lipid rafts that serve as platforms for molecules engaged in cell activity, therefore providing a target against inappropriate cell response leading to chronic inflammation. We found that pantethine-treated cells showed a significant change in raft fatty acid composition and cholesterol content, wit…

2020

Over the last decade, the E3-ubiquitine ligases from IAP (Inhibitor of Apoptosis) family have emerged as potent regulators of immune response. In immune cells, they control signaling pathways driving differentiation and inflammation in response to stimulation of tumor necrosis factor receptor (TNFR) family, pattern-recognition receptors (PRRs), and some cytokine receptors. They are able to control the activity, the cellular fate, or the stability of actors of signaling pathways, acting at different levels from components of receptor-associated multiprotein complexes to signaling effectors and transcription factors, as well as cytoskeleton regulators. Much less is known about ubiquitination …

Development of polypeptide-based therapeutics for the treatment of castration resistant prostate cancer

2019

El cáncer de próstata (CaP) es el segundo cáncer más frecuente en los hombres. Los estudios han establecido el gen de fusión (T2E) compuesto por TMPRSS2 (serina proteasa dependiente de andrógenos) y ERG (factor de transcripción de la familia ETS) como un biomarcador potencial de CaP. La progresión en el CaP incluye tanto el receptor de andrógenos (AR) como el receptor del factor de crecimiento de insulina 1 (IGF-1R), y el tratamiento con un anticuerpo anti-IGF-1R (AVE1642) ha demostrado un gran potencial en el tratamiento de los pacientes con CaP T2E-positivos. Por ello, el desarrollo de terapias personalizadas basadas en polímeros terapéuticos puede favorecer el tratamiento de CaP para un …

Characterization of grapevine defense reactions and identification of elicitors : the endopolygalacturonase 1 from Botrytis cinerea, an avirulence fu…

2002

The fight against grapevine pathogens is mainly carried out by pesticides, the continued use of which is harmful to the environment and the health of users and consumers. The main organizations in charge of viticulture set as a priority the research and use of alternatives to chemical control. However, the genetic improvement of the vine is prohibited in AOC vineyards to preserve the varietal typicity, partly responsible for the quality of the wines. In addition, research undertaken some fifteen years ago reveals that plants have their own immune defenses, which they activate on contact with the microorganisms they recognize via molecules called elicitors. In this context, the objective of …

Ca2+ signaling in taste bud cells and spontaneous preference for fat: Unresolved roles of CD36 and GPR120

2013

Recent compelling evidences from rodent and human studies raise the possibility for an additional sixth taste modality devoted to oro-gustatory perception of dietary lipids. Understanding the mechanisms underlying oro-gustatory detection of dietary fat is critical for the prevention and treatment of obesity. A number of studies have suggested that lingual CD36, a glycoprotein, highly expressed by circumvallate papillae of the tongue, is implicated in the perception of dietary fat taste. G protein-coupled receptors (GPCRs) are important signaling molecules for many aspects of cellular functions. It has been shown that these receptors, particularly GPR120, are also involved in lipid taste per…

Membrane vesicles shed by oligodendroglioma cells induce neuronal apoptosis.

2006

In order to investigate the mechanism by which oligodendrogliomas cause neuronal damage, media conditioned by G26/24 oligodendroglioma cells, were fractionated into shed vesicles and vesicle-free supernatants, and added to primary cultures of rat fetal cortical neurons. After one night treatment with vesicles, a reproducible, dose-dependent, inhibitory effect on neurite outgrowth was already induced and, after 48-72 h of incubation, neuronal apoptosis was evident. Vesicle-free supernatants and vesicles shed by NIH-3T3 cells had no inhibitory effects on neurons. Western blot analyses showed that treated neurons expressed a decreased amount of neurofilament (NF), growth-associated protein (GA…

Hsp60 is actively secreted by human tumor cells

2010

Background Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination. Methodology/Principal Findings S…

Inhibition of stearoyl-CoA desaturase 1 expression induces CHOP-dependent cell death in human cancer cells.

2010

Background Cancer cells present a sustained de novo fatty acid synthesis with an increase of saturated and monounsaturated fatty acid (MUFA) production. This change in fatty acid metabolism is associated with overexpression of stearoyl-CoA desaturase 1 (Scd1), which catalyses the transformation of saturated fatty acids into monounsaturated fatty acids (e.g., oleic acid). Several reports demonstrated that inhibition of Scd1 led to the blocking of proliferation and induction of apoptosis in cancer cells. Nevertheless, mechanisms of cell death activation remain to be better understood. Principal Findings In this study, we demonstrated that Scd1 extinction by siRNA triggered abolition of de nov…

Type-2 histones deacetylases and cryptogein-induced cell death in tabacco

2011

Cryptogein, which is secreted by the oomycete Phytophthora cryptogea, is a proteinaceous elicitor of plant defense reactions that activates a set of signaling events leading to the hypersensitive response and to systemic acquired resistance. Although the early cytosolic signaling events induced by cryptogein are well described, the only nuclear events characterized to date are the variations in free calcium concentrations and defense-related gene expression. The characterization of the activation of cytosolic protein kinases, including WIPK and SIPK, by phosphorylation in response to cryptogein highlights the key-role played by posttranslational modifications in cryptogein-induced signaling…

Shed membrane vesicles and clustering of membrane-bound proteolytic enzymes

2003

Publisher Summary Eukaryotic cells appear to release into the extracellular medium several populations of exovesicles, which are suggested to have different origins and functions and are identified by different names. This chapter deals with vesicles believed to originate from the cell membrane and named membrane vesicles. These are structures in which membrane-bound proteolytic enzymes are clustered and they play important roles in matrix remodeling. Relatively large membrane vesicles (diameters ranging from 100 nm to 1 μm) are shed from plasma membranes through unidentified budding mechanisms. These membrane structures are enriched in selected plasma-membrane components including integrin…