A promising target for the treatment of painful diseases. Ministry of Health Oswaldo Cruz Foundation Oswaldo Cruz Institute Cellular Comunication Laboratory Immunopharmacology Laboratory The P2X7R activation and its correlation with the inflammatory and nociceptive signaling: A promising target for the treatment of painful diseases. Rômulo José Soares Bezerra, PhD. E-mail: cyentysta@gmail.com
Purinergic Receptors Purinergic Receptors P1 Receptors P2 Receptors (activated by adenosine) P2 Receptors (activated by nucleotides) A1, A2A, A2B, A3 P2Y G-coupled P2X Ionotropic P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, P2Y14 P2X1, P2X2, P2X3, P2X4, P2X5, P2X6, P2X7 Ravelic & Burnstock, 1998.
Expression of P2X7R in mammals Cells from CNS: Microglia; Astrocytes; Oligodendrocytes; Some neurons populations. Cells of the hematopoietic lineage: Monocytes; Macrophages; Lymphocytes; Mast cells; Dendritic cells. Astrocytes Microglia Oligodendrocytes Neurons Macrophages Monocytes Dendritic cells Lymphocytes Mast cells Ravelic & Burnstock, 1998; Lister et al., 2007; Coddou et al., 2011.
? Activation of P2X7 Receptor extracellular intracellular Na+ Ca++ Na+ BE LY Na+ Ca++ YP ATP ATP ATP Na+ Na+ YP ? IP Ca++ ATP ATP Na+ Ca++ BE LY extracellular ATP ATP intracellular K+ K+ IP 668,39 Da K+ K+ BE 394,31 Da K+ LY 457,24 Da YP 629 Da
Effects associated to P2X7R activated Cell death Inflammasome activation ROS generation Caspases activation Transcription factors activation such NF-κB and proinflammatory genes transcription such COX-2 and iNOS Cytokines secretion: IL-1β, IL-18 e TNF-α Phospholipases secretion: PLA2 and PLD MAPK activation Lister et al., 2007; Friedle et al., 2010; Bartlett et al., 2014; Rein & Torres, 2009; Riteau et al., 2012; Latz et al., 2013; Honore et al., 2006; Barberà-Cremades et al., 2012. 1. Proinflammatory profile; 2. Pro-nociceptive.
Diseases associated with P2X7R Important therapeutic target - Neurophatic pain - Buchanan et al., 2006. - Neurodegenerative diseases - Friedle; Curet & Watters, 2010. - Rheumatoid arthritis - Burnstock et al., 2009. - Chronic inflammation - Lister et. al., 2007.
Activity from new natural compounds discovered by our research group • Our aim: Identify new compounds from natural proucts that may be candidates for potential antagonist to P2X7 receptor.
Screening Method
Extracts with activity Natural Products Library EXTRACTS Extracts with activity Active extracts P1A2 A P1H11 P2A2 A P2H11 1 8067 P3A2 A P3H11 P4A2 A P4H11 P5A2 A P5H11 2 8549 & 8568 P6A2 A P6H11 P7A2 A P7H11 P8A2 A P8H11 P9A2 A P9H11 P10A2 A P10H11 P11A2 A P11H11 P12A2 A P12H11 P13A2 A P13H11 P14A2 A P14H11 P15A2 A P15H11 P16A2 A P16H11 P17A2 A P17H11 P18A2 A P18H11 P19A2 A P19H11
Inhibitory Concentration (IC50) obtained
Inhibitory Concentration (IC50) obtained
Inhibitory Concentration (IC50) obtained
Activity on the IL-1β Release
Activity on the Nitric Oxide Release
Activity on the Reactive Oxygen Species (ROS) release
Cytotoxicity
Pharmacologic Characterization
Nociception
Nociception
Next Steps
Synthetic Compounds Alves, L.A. et al. 2013
Natural Compounds
Thank You!
Inhibition of pain in vivo models using P2X7 antagonists Pain attenuation in vivo models of neurophatic pain Pain attenuation in vivo models of inflammatory pain Labasi et al., 2002; Honore et al., 2006; McGaraughty et al., 2007.
Compound: Amentoflavone Inhibition of pain in vivo models using P2X7 antagonists from natural products Rheedia longifolia Compound: Amentoflavone - P2X7 Santos, J.A.A et al., 2010. Model of writhing induced by acetic acid using the leaves of Rheedia longifolia Triana & Planch
Inhibition of pain in vivo models using P2X7 antagonists from natural products Number of indomethacin induced gastric lesions Model of neurogenic nociception induced by capsaicin Inflammatory nociception observed by von Frey model