Developmental expression of metabotropic P2Y(1) and P2Y(2) receptors in freshly isolated astrocytes from rat hippocampus.
There are at least three subtypes of cloned metabotropic P2 receptors linked to intracellular Ca(2+) rises in rat brain cells, namely, P2Y(1), P2Y(2) and P2Y(4). In this study we explore the subtypes of the metabotropic P2 receptors seen in freshly isolated astrocytes (FIAs) from P8-P25 rats. We found by single cell RT-PCR that in process-bearing FIAs from hippocampi of P8-P12 rats, 31% of the glial fibrillary acidic protein (GFAP) mRNA (+) cells expressed P2Y(1) mRNA while only 5% of the cells tested expressed P2Y(2) mRNA. The expression of P2Y(1) receptor mRNA was not changed in FIAs from the hippocampi of P18-P25 rats, but 38% of the GFAP mRNA (+) cells in the P18-P25 age group then showed P2Y(2) mRNA. We also studied whether the mRNA was expressing functional receptor protein by measuring Ca(2+) responses to specific agonists for P2Y(1) and P2Y(2). We found that similar proportions of GFAP mRNA (+) FIAs responded to ATP or UTP as showed mRNAs for P2Y (1) and P2Y(2,) respectively. Total tissue RNA from P9 and P24 rat hippocampus showed a 2.8-fold increase in P2Y(2) mRNA levels from P9 to P24 with a decrease in P2Y(1) mRNA. Thus, this study shows a marked up-regulation of mRNA for P2Y(2) from 9 to 24 days in rat hippocampus, and some of this increase is likely due to the protoplasmic astrocytes which is being translated into functional receptor protein in these cells.
Zhu
Y
Y
Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, USA.
Kimelberg
H K
HK
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis / Q000235:genetics; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis* / Q000235:genetics; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014544:Uridine Triphosphate / Q000494:pharmacology
D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; C546384:P2ry1 protein, rat; C546387:P2ry2 protein, rat; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D000255:Adenosine Triphosphate; D014544:Uridine Triphosphate