Actualités

L'article "No answer to the lack of specificity: mouse monoclonal antibody targeting the angiotensin II type 1 receptor AT1 fails to recognize its target" vient de paraître dans le journal "Naunyn-Schmiedeberg's Archives of Pharmacology"

Auteurs : Marie-Lynda Bouressam, Isabelle Lartaud, François Dupuis, Sandra Lecat

Référence de l'article : 2018 Jun 4. doi: 10.1007/s00210-018-1522-4. [Epub ahead of print]

Abstract :

Numerous antibodies targeting G protein-coupled receptors (GPCRs) have been described as non-specific among the polyclonal antibodies against angiotensin II type 1 receptor (AT1). We have tested the newly developed AT1 receptor mouse monoclonal antibody for its specificity. Human embryonic kidney (HEK293) cells, which do not endogenously express AT1 receptor, were transfected in order to overexpress a fluorescently labeled enhanced green fluorescent protein (EGFP)-tagged human AT1 receptor. Western blot and immunofluorescence assays were performed to test the specificity of the Santa Cruz monoclonal antibody sc-57036. These results were compared to the ones obtained with the polyclonal sc-1173 anti-AT1 receptor antibodies that have already been described as non-specific. While the positive controls using GFP antibodies detected the EGFP-tagged AT1 receptor, both polyclonal and monoclonal anti-AT1 receptor antibodies failed to specifically recognize the corresponding band by Western blot, as similar bands were revealed in either transfected or non-transfected cells. It also failed to detect AT1 receptor in immunofluorescence experiments. The lack of target recognition of the monoclonal AT1 receptor antibody in our experimental conditions suggests that this antibody could give misleading results such as misidentification of the protein. To our knowledge, no specific antibodies targeting AT1 receptors have been developed so far and the field is thus in need of new technical developments.

Programme pour les conférences du vendredi 15 juin 2018

Conférence du Dr Amedea B Seabra du Center for Natural and Human Sciences Federal University of ABC (Brésil) le 15 juin à la Faculté de Pharmacie de Nancy

"Nitric oxide releasing biomaterials for biomedical and agricultural applications"

The free radical nitric oxide (NO) plays a key role in several biological processes in mammals, such as the control of vasodilation, the immunological responses, the inhibition of platelet adhesion, the cell communication, anti-cancer activities, and the wound healing. In addition, NO is recognized as important molecule in several physiologic process in plants, including break seed dormancy, stimulate plant germination and greening, control iron homeostasis in plants, and improve plant tolerance to salinity, metal toxicity, temperature and drought stress. As a free radical, NO donors are administrated in several applications. Among them, S-nitrosothiols (RSNOs) are an important class of NO donors, since they spontaneously decompose releasing NO, and this decomposition can be triggered by light irradiation (visible region). Several papers in the literature reveal that the combination of nanotechnology and RSNOs is a promising strategy to allow the therapeutic uses of NO. In this context, this presentation focuses on the synthesis strategies, characterization, in vitro and in vivo applications of NO-based metallic and polymeric nanoparticles, hydrogels and films  for biomedical and agriculture applications.

Lors de la 3ème édition du congrès “Analytical methods to study oxidative damages, antioxidants and drugs” qui se déroulera du 24 au 26 Mai 2018 à Bialystok (Pologne), le Dr Caroline GAUCHER donnera une conférence intitulée "Protein S-nitrosation as a biomarker of nitric oxide bioavailability under oxidative stress"

L'article "Glutathione: antioxidant properties dedicated to nanotechnologies" vient de paraître dans le journal "Antioxidants", special issue "Inspired by Nature: Antioxidants and Nanotechnologies".

Auteurs : Gaucher C., Boudier A., Bonetti J., Clarot I., Leroy P., Parent M.

Référence de l'article : Antioxidants 2018, 7(5), 62; https://doi.org/10.3390/antiox7050062

Abstract :

Which scientist has never heard of glutathione (GSH)? This well-known low-molecular-weight tripeptide is perhaps the most famous natural antioxidant. However, the interest in GSH should not be restricted to its redox properties. This multidisciplinary review aims to bring out some lesser-known aspects of GSH, for example, as an emerging tool in nanotechnologies to achieve targeted drug delivery. After recalling the biochemistry of GSH, including its metabolism pathways and redox properties, its involvement in cellular redox homeostasis and signaling is described. Analytical methods for the dosage and localization of GSH or glutathiolated proteins are also covered. Finally, the various therapeutic strategies to replenish GSH stocks are discussed, in parallel with its use as an addressing molecule in drug delivery.

Communication orale au congrès Printemps de la Cardiologie :

S-nitrosation decreases AT1 receptor mediated vasoconstriction and myogenic tone on rat middle cerebral arteries par M-L BOURESSAM, Doctorante

Présentation orale lors de la Journée Scientifique de l'école doctorale BioSE du 28 mars 2018 :

Derivatization methods with liquid chromatography- HCD tandem mass spectrometry for the measurement of nitric oxide species coming from S-nitrosoglutathione par H. YU, Doctorante

L'article "Polymeric nanoparticles for increasing oral bioavailability of curcumin" vient de paraître dans le journal "Antioxidants", dans l'issue spéciale "Inspired by nature : Antioxidants and Nanotechnology".

Auteurs : Anita Umerska, Caroline Gaucher, Felipe Oyarzun-Ampuero, Isabelle Fries-Raeth, Florence Colin, Maria Gabriela Villamizar-Sarmiento, Philippe Maincent, Anne Sapin-Minet.

Référence de l'article : Antioxidants 2018, 7(4), 46; https://doi.org/10.3390/antiox7040046

Article accessible en cliquant ici.

Abstract :

Despite the promising biological and antioxidant properties of curcumin, its medical applications are limited due to poor solubility in water and low bioavailability. Polymeric nanoparticles (NPs) adapted to oral delivery may overcome these drawbacks. Properties such as particle size, zeta potential, morphology and encapsulation efficiency were assessed. Then, the possibility of storing these NPs in a solid-state form obtained by freeze-drying, in vitro curcumin dissolution and cytocompatibility towards intestinal cells were evaluated. Curcumin-loaded Eudragit® RLPO (ERL) NPs showed smaller particle diameters (245 ± 2 nm) and better redispersibility after freeze-drying than either poly(lactic-co-glycolic acid) (PLGA) or polycaprolactone (PCL) NPs. The former NPs showed lower curcumin encapsulation efficiency (62%) than either PLGA or PCL NPs (90% and 99%, respectively). Nevertheless, ERL NPs showed rapid curcumin release with 91 ± 5% released over 1 h. The three curcumin-loaded NPs proposed in this work were also compatible with intestinal cells. Overall, ERL NPs are the most promising vehicles for increasing the oral bioavailability of curcumin.

Offres de recrutements (un doctorat et un post-doctorat) financés par Lorraine Université d'Excellence (LUE) IMPACT Biomolecules. Date limite d'envoi de candidature : 30 avril 2018.

Pour plus de renseignements, contacter le Dr Caroline GAUCHER caroline.gaucher@univ-lorraine.fr