1. 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.

2. 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.

3. 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.

4. ? 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

5. 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.

6. 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.

7. 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.

8. Screening Method

9. 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

10. Inhibitory Concentration (IC50) obtained

11. Inhibitory Concentration (IC50) obtained

12. Inhibitory Concentration (IC50) obtained

13. Activity on the IL-1β Release

14. Activity on the Nitric Oxide Release

15. Activity on the Reactive Oxygen Species (ROS) release

16. Cytotoxicity

17. Pharmacologic Characterization

18. Nociception

19. Nociception

20. Next Steps

21. Synthetic Compounds
Alves, L.A. et al. 2013

22. Natural Compounds

23. Thank You!

24. 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.

25. 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

26. 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