Participação de Tatiana Victoni em Congresso na França

 7ème Congrès de Physiologie, Pharmacologie et Thérapeutique 04-06 Avril 2012, Dijon, France

Involvement of purinergic receptors and NLRP3 inflammasome pathway in the ATP-induced cytokine release and MMPs/TIMP imbalance in macrophages

Dr. Thomas GICQUEL^a, Dr. Tatiana VICTONI^b, Dr. Alain FAUTREL^c, Mle Isabelle GUENON^b, Dr. Isabelle COUILLIN^d, Pr. Elisabeth BOICHOT^b, Pr. Vincent LAGENTE^b

^a INSERM UMR 991/Université Rennes 1, Rennes, France, ^b UMR 991 INSERM, Université de Rennes 1, Rennes, France, ^c H2P2 Histopathological platform, IFR140, Université de Rennes 1, Rennes, France, ^d UMR-IEM CNRS 6218, Université d'Orléans, France

Adenosine triphosphate (ATP) has been described as a danger signal activating Nod-like receptor family, pyrin domain containing 3 (NLRP3) Inflammasome and the proinflammatory cytokine IL-1β release in lung. This pathway has been previously described to be involved in various inflammatory diseases including fibrosis.
We investigated the role of ATP as a danger signal and purinergic receptors in the activation of NLRP3-Inflammasome pathway in human macrophages. Moreover, we evaluated the influence of the activation by ATP in the release of pro-inflammatory cytokines and the balance MMPs/TIMP.
Monocytes from healthy donors were obtained from buffy coat (EFS, Rennes) using human CD14 Microbeads (Miltenyi) separation kit. Macrophages were obtained after differentiation from monocytes by incubation with rhGM-CSF for 7 days. Cytokines and MMPs production was measured in the supernatant using ELISA or zymography. NLRP3 expression was evaluated by immunohistochemistry.
LPS and ATP elicited an increased production of IL-6, IL-18 or IL-1β at 4h30 and 24h. TIMP-1 secretion, a pro-fibrogenic cytokine was also increased at 4h30 and 24h. Gelatinase expression, mainly MMP-9 was increased at 24h as observed in zymography and confirmed by ELISA. In addition, NLRP3 protein expression was increase at 24h in LPS+ATP primed cells. To investigate the involvement of purinergic receptors, macrophages were pretreated with suramine, an antagonist of P2 receptors.
Suramine significantly reduced the production of TIMP-1 at 4h30 and 24h as well as IL-1β and IL-6. These results showed that ATP could be a major endogenous danger signal that engages NLRP3 and P2 receptor leading to inflammatory process and cytokine release. This probably alters the MMPs/TIMP equilibrium which influences the extracellular matrix deposition and fibrosis.
Financial support: INSERM, CHU Rennes and ANR PURPID
Keywords : NLRP3 inflammasome, IL-1beta, Purinergic receptors, Matrix metalloproteinase