Search results for "HeLa"

Bachelard à l’origine d’une nouvelle philosophie de l’existence ?

2013

International audience

Modulation of Efficient Diiodo-BODIPY in vitro Phototoxicity to Cancer Cells by Carbon Nano-Onions

2020

Photodynamic therapy (PDT) is currently one of the most promising approaches for targeted cancer treatment. It is based on responses of vital physiological signals, namely reactive oxygen species (ROS), which are associated with diseased condition development, such as tumors. This study presents the synthesis, incorporation, and application of a diiodo-BODIPY based photosensitizer, based on a non-covalent functionalization of carbon nano-onions (CNOs). In vitro assays demonstrate that HeLa cells internalize the diiodo-BODIPY molecules, and their CNOs nanohybrids. Upon cell internalization and light exposure, the pyrene-diiodo-BODIPY molecules induce an increase of the ROS level of HeLa cell…

Characterization and transcription studies of a phytochelatin synthase gene from the solitary tunicate Ciona intestinalis exposed to cadmium.

2014

The major thiol-containing molecules involved in controlling the level of intracellular ROS in eukaryotes, acting as a nonenzymatic detoxification system, are metallothioneins (MTs), glutathione (GSH) and phytochelatins (PCs). Both MTs and GSH are well-known in the animal kingdom. PC was considered a prerogative of the plant kingdom but, in 2001, a phytochelatin synthase (PCS) gene was described in the nematode Caenorhabditis elegans; additional genes encoding this enzyme were later described in the earthworm Eisenia fetida and in the parasitic nematode Schistosoma mansoni but scanty data are available, up to now, for Deuterostomes. Here, we describe the molecular characteristics and transc…

Complex formation of copper(II) and cadmium(II) with pectin and polygalacturonic acid in aqueous solution. An ISE-H + and ISE-Me 2+ electrochemical s…

2012

The acid-base properties of pectin and its ability to complex with copper(II) or cadmium(II) were quantitatively determined in order to define the ability of this natural polyelectrolyte to sequester metal ions. Potentiometric measurements carried out at different ionic strengths (0.1 - 0.7 mol L-1, in Na+ ionic medium) allowed us to define the acid-base properties of pectin together with the dependence of the protonation constants on ionic strength and to calculate the protonation constant at infinite dilution. The formation of complex species between pectin and copper(II) or cadmium(II) was investigated potentiometrically (using H+, Cu2+ and Cd2+ Ion Selective Electrodes, ISEs) in NaNO3 a…

RAB18 Loss Interferes With Lipid Droplet Catabolism and Provokes Autophagy Network Adaptations

2020

Autophagy is dependent on appropriate lipid supply for autophagosome formation. The regulation of lipid acquisition and the autophagy network response to lipid-limiting conditions are mostly elusive. Here, we show that the knockout of the RAB GTPase RAB18 interferes with lipid droplet catabolism, causing an impaired fatty acid release. The resulting reduced lipid-droplet-derived lipid availability influences autophagy and provokes adaptive modifications of the autophagy network. These adjustments include increased expression and phosphorylation of ATG2B as well as augmented formation of the ATG12-ATG5 conjugate. Moreover, ATG9A shows an enhanced phosphorylation at amino acid residues tyrosi…

Activation of NF-kappaB and IL-8 by yersinia enterocolitica invasin protein is conferred by engagement of rac1 and MAP kinase cascades.

2003

International audience; Yersinia enterocolitica triggers activation of the nuclear factor (NF)-kappaB and production of the proinflammatory chemokine interleukin (IL)-8 in intestinal epithelial cells. This activation is due to adhesion of the bacteria via their outer membrane protein invasin to the host cells. Using Clostridium difficile toxins that specifically inactivate small GTPases, and transfection of inhibitory proteins of the Rho-GTPases, we demonstrate that Rac1, but not Cdc42 or Rho, is required for activation of NF-kappaB by invasin. Invasin activated the mitogen activated protein kinases (MAPK) p38 and c-Jun N-terminal protein kinase (JNK) but not extracellular signal regulated …

Aplidin® induces JNK-dependent apoptosis in human breast cancer cells via alteration of glutathione homeostasis, Rac1 GTPase activation, and MKP-1 ph…

2006

Aplidin® is an antitumor agent in phase II clinical trials that induces apoptosis through the sustained activation of Jun N-terminal kinase (JNK). We report that Aplidin® alters glutathione homeostasis increasing the ratio of oxidized to reduced forms (GSSG/GSH). Aplidin® generates reactive oxygen species and disrupts the mitochondrial membrane potential. Exogenous GSH inhibits these effects and also JNK activation and cell death. We found two mechanisms by which Aplidin® activates JNK: rapid activation of Rac1 small GTPase and downregulation of MKP-1 phosphatase. Rac1 activation was diminished by GSH and enhanced by L-buthionine (SR)-sulfoximine, which inhibits GSH synthesis. Downregulatio…

Uz vēža šūnām mērķēti alfa daļiņu emiteri, jauna kompleksējoša savienojuma sintēzes metodes izstrāde

2015

Vēzis ir viena no mūsdienu medicīnas svarīgākajām problēmām. Mērķēta alfa-terapija, kas izmanto pie bioloģiskiem nesējiem piesaistītus α-daļiņas emitējošus radionuklīdus un tiek mērķēta selektīvi uz malignajām šūnām, ir veids, kā iznīcināt atsevišķas vēža šūnas, pat ja tās ir izkaisītas pa visu organismu. Šī darba mērķis ir apkopot informāciju par α-emiteru izmantošanu onkoterapijā, kā arī akcentēt galvenos farmācijas un ķīmijas saskares punktus uz audzēja šūnām mērķētu radiofarmaceitisko vielu izstrādē. Darba teorētiskajā daļā apkopota zinātniskajā literatūrā pieejamā informācija par α emiteriem, to pieejamību, darbības principu, priekšrocībām un potenciālajām iespējām onkoterapijā. Sniegt…

La place et l'influence de l'épistémologie bachelardienne

2009

La Reggia di Venaria Reale in Italy and Palacio Real de Aranjuez in Spain: history, restoration and significance, comparative study between Two Royal…

2017

La investigación relaciona dos sitios reales, La Reggia di Venaria Reale en Italia y el Palacio Real de Aranjuez en España, confrontando su desarrollo histórico y arquitectónico, las obras de restauración llevadas a cabo, los criterios para su inclusión en la Lista de Patrimonio Mundial y su uso hoy en día como museos. El estudio comparativo muestra cómo ambos palacios se usaban inicialmente como residencias de caza en lugares con abundancia de agua y pesca. Además, los dos están ubicados cerca de las capitales políticas de su tiempo; esto es, Turín y Madrid. El hecho que el mismo arquitecto – Filippo Juvarra estuviera presente en ambas residencias reales contribuye a las similitudes, y en …