Anales RANF

P.16 DESIGN, SYNTHESIS, AND PHARMACOLOGICAL EVALUATION OF NOVEL P2X7R ANTAGONISTS POTENTIALLY TARGETING THE CNS F. Calzaferri 1,2 , A.M.G. de Diego 4 , R. de Pascual 1,2 , P. Narros 1,3 , J. Egea 1,3 , E.M. García-Frutos 5 , A.G. García 1,2,3 , C. de los Ríos 1,3 1 . Instituto Teófilo Hernando, Madrid, Spain; 2 . Universidad Autónoma de Madrid, Madrid, Spain; 3 . Hospital Universitario de La Princesa, Madrid, Spain; 4 . DNS Neuroscience, Madrid, Spain; 5 . Consejo Superior de Investigaciones Científicas, Madrid, Spain. The purinergic P2X7 receptor (P2X7R) is a ligand-gated ion channel physiologically activated by high concentrations of ATP that occur after tissue or cell damage. Its activity is correlated with inflammatory signalling and the promotion of cell death, which are causes of several neurodegenerative, neurological, and psychiatric diseases. In this work, we plan to design and synthesise new antagonists capable of crossing the blood-brain barrier (BBB) to block the P2X7R activity in the central nervous system (CNS). After a rational design supported by computational aids, twenty-six compounds have been synthesised so far and they are being pharmacologically screened in a cell line expressing the P2X7R. Fluorescence calcium dynamics and YO-PRO-1 dye uptake assays are used in HEK293-hP2X7R cells, while the P2X7R-induced IL- 1β release is measured in bone marrow-derived macrophages. From a first screening in intraperitoneal macrophages, two compounds, i.e. ITH15004 and ITH15006, revealed a certain functional blockade of the receptor. However, further investigation is needed to confirm their mechanism of action. These first results allowed us to design novel optimised compounds based on the molecular structure of ITH15004 and ITH15006, so to define full structure-activity relationships. The disclosure of a new P2X7R antagonist hit with appropriate characteristics for crossing the BBB will permit further in vitro and in vivo studies in models of the above mentioned CNS diseases, as well as precise structural optimisation to follow with the development of a potential final clinical candidate.