The purinergic receptor P2X5 contributes to bone loss in experimental periodontitis

Purinergic receptor signaling is increasingly recognized as an important regulator of inflammation. The P2X family purinergic receptors P2X5 and P2X7 have both been implicated in bone biology, and it has been suggested recently that P2X5 may be a significant regulator of inflammatory bone loss. However, a role for P2X5 in periodontitis is unknown. The present study aimed to evaluate the functional role of P2X5 in ligature-induced periodontitis in mice. Five days after placement of ligature, analysis of alveolar bone revealed decreased bone loss in P2rx5(−/−) mice compared to P2rx7(−/−) and WT control mice. Gene expression analysis of the gingival tissue of ligated mice showed that IL1b, IL6, IL17a and Tnfsf11 expression levels were significantly reduced in P2rx5(−/−) compared to WT mice. These results suggest the P2X5 receptor may regulate bone loss related to periodontitis and it may thus be a novel therapeutic target in this oral disease.