Abstract
Rat bone marrow stromal cells express G protein-coupled purinergic receptor (P2Y2 receptor). We investigated intracellular Ca2+ signals in these cells using Fura 2-AM and found that UTP, an agonist of P2Y2 receptor, induced Ca2+ rise (Ichikawa, J. and Gemba, H. (2005) Jpn.J.Physiol. 55(Suppl.): S124, Ichikawa, J. and Gemba, H. (2006) J.Physiol.Sci. 56(Suppl.): S155). In several types of cells, it was reported that the activation of purinergic receptors induced cell proliferation (J.Neurochem. (2006) 99(3): 913-923, Br.J.Pharmacol. (2003) 139(6): 1119-1126). Here, we investigated the effect of the activation of P2Y2 receptor on cell proliferation of rat bone marrow stromal cells. We added the agonist of P2Y2 receptor (UTP or ATP) to culture media, and assayed cell number by measuring Calcein-AM fluorencence intensity. In the presence of 10% FCS, the addition of UTP (or ATP, 1-100μM) enhanced cell proliferation. At higher concentration (1000μM), UTP (or ATP) induced cell death. In serum-free condition, UTP (or ATP, 1-1000μM) did not induce the remarkable cell proliferation although they expressed functional P2Y2 receptor in these cultures. It is suggested that UTP (or ATP) itself does not induce cell proliferation but assists it in serum-existing condition. [J Physiol Sci. 2007;57 Suppl:S223]
