IDENTIFICATION AND CLONING OF HUMAN P-2U PURINOCEPTOR PRESENT IN OSTEOCLASTOMA, BONE, AND OSTEOBLASTS

Extracellular ATP acting through purinoceptors may be an important fac tor in the modulation of bone turnover, In this study we cloned and se quenced the P-2U purinoceptor from osteoclastoma, confirming the recen tly published human sequence. Furthermore, by the reverse transcriptas e-linked polymerase chain reaction (RT-PCR) and Southern blotting we d emonstrated expression of P-2U receptor mRNA in bone, primary cultures of human bone-derived cells, and two osteosarcoma cell lines, Saos2 a nd Te85. P-2U receptor transcripts were identified in alkaline phospha tase-positive human bone-derived cells isolated by now cytometry provi ding strong evidence for the expression of the P-2U purinoceptor in ma ture osteoblasts. P-2U receptor transcripts were also detected in a pu rified giant cell population isolated hom osteoclastoma, indicating th at this receptor is also expressed by osteoclasts. These data suggest that purinergic agonists may play a role in the regulation of bone met abolism.