Gilles Devouassoux, Eric Thiaudière, Colleen Cardiet, Philippe Mellet, Indranil Duttagupta, Elodie Parzy, Anne Pizzoccaro, Sylvain R. A. Marque, Nicolas Vanthuyne, Jean-Michel Franconi, Philippe Massot, Abderrazzak Bentaher, Gérard Audran, Angélique Rivot, Natacha Jugniot, Marion Jean, Pierre Voisin, Centre de résonance magnétique des systèmes biologiques (CRMSB), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Physiopathologie de l'immunodépression associée aux réponses inflammatoires systémiques - EA 7426 (PI3), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Vorozhtsov Novosibirsk Institute of Organic Chemistry (RAS, SB, NN ), ANR-15-CE18-0012,PULMOZYMAGE,Imagerie des maladies inflammatoires pulmonaires via leurs activités enzymatiques à l'aide de L'IRM rehaussée par l'effet Overhauser et des substrats nitroxydes à déplacement de raies(2015), ANR-10-IDEX-0003,IDEX BORDEAUX,Initiative d'excellence de l'Université de Bordeaux(2010), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), European Project: 609102,EC:FP7:PEOPLE,FP7-PEOPLE-2013-COFUND,PRESTIGE(2014), VIAUD, Karine, Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Institut de Génomique Fonctionnelle (IGF), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes - UFR Arts & Sciences Humaines (UGA UFR ARSH), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Physiopathologie de l'immunodépression associée aux réponses inflammatoires systémiques / Pathophysiology of Injury-induced Immunosuppression (PI3), and Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)
WOS:000445759000010; International audience; Pulmonary inflammatory diseases are a major burden worldwide. They have in common an influx of neutrophils. Neutrophils secrete unchecked proteases at inflammation sites consequently leading to a protease/inhibitor imbalance. Among these proteases, neutrophil elastase is responsible for the degradation of the lung structure via elastin fragmentation. Therefore, monitoring the protease/inhibitor status in lungs non-invasively would be an important diagnostic tool. Herein we present the synthesis of a MeO-Suc-(Ala)(2)-Pro-Val-nitroxide, a line-shifting elastase activity probe suitable for Electron Paramagnetic Resonance spectroscopy (EPR) and Overhauser-enhanced Magnetic Resonance Imaging (OMRI). It is a fast and sensitive neutrophil elastase substrate with K-m = 15 +/- 2.9 mu M, k(cat)/K-m = 930,000 s(-1) M-1 and K-m = 25 +/- 5.4 mu M, k(cat)/K-m = 640,000 s(-1) M-1 for the R and S isomers, respectively. These properties are suitable to detect accurately concen trations of neutrophil elastase as low as 1 nM. The substrate was assessed with broncho-alveolar lavages samples derived from a mouse model of Pseudomonas pneumonia. Using EPR spectroscopy we observed a clear-cut difference between wild type animals and animals deficient in neutrophil elastase or deprived of neutrophil Elastase, Cathepsin G and Proteinase 3 or non-infected animals. These results provide new preclinical ex vivo and in vivo diagnostic methods. They can lead to clinical methods to promote in time lung protection.