Cellular expression of P2Y and beta-AR receptor mRNAs and proteins in freshly isolated astrocytes and tissue sections from the CA1 region of P8-12 rat hippocampus

Brain Res Dev Brain Res. 2004 Jan 31;148(1):77-87. doi: 10.1016/j.devbrainres.2003.10.014.

Abstract

Although almost all GFAP(+) cells in primary astrocyte cultures show functional beta-adrenergic (beta-AR) and metabotropic purinergic (P2Y) receptors, the fewer studies on astrocytes in situ have shown that a much smaller proportion express these same receptor-mediated activities. Here we show, by multiplex single cell RT-PCR, that 44% of freshly isolated, GFAP(+) astrocytes (FIAs) from the CA1 of P8-12 rat hippocampus always co-express beta-adrenergic receptor mRNA subtypes with metabotropic ATP receptor mRNA subtypes (P2Y1, P2Y2 or P2Y4). We also found that beta2 mRNA was the dominant beta-AR subtype expressed. P2Y1 mRNA always co-expresses with either one or two subtypes of P2U-like receptor (P2Y2 or P2Y4) mRNAs. Immunocytochemical studies showed a similar percentage of all FIAs expressed beta-AR and P2Y1 protein (54% and 52%, respectively), as for the mRNAs (46% and 65%, respectively). The staining of hippocampal sections for beta-AR or P2Y1 receptor plus GFAP shows that there are quite numerous, scattered star-shaped GFAP(+) astrocytes in the CA1 region of P9-10 rat hippocampus that stained positive for either of these receptors. These data show that astrocytes in situ express, and to a large extent likely co-express, beta-AR and P2Y receptors.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging
  • Animals
  • Animals, Newborn
  • Astrocytes / metabolism*
  • Cell Count
  • Cells, Cultured
  • Glial Fibrillary Acidic Protein / metabolism
  • Hippocampus / cytology*
  • Hippocampus / growth & development
  • Immunohistochemistry / methods
  • RNA, Messenger / biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Adrenergic, beta / biosynthesis*
  • Receptors, Purinergic P2 / biosynthesis*
  • Receptors, Purinergic P2Y1
  • Receptors, Purinergic P2Y2
  • Reverse Transcriptase Polymerase Chain Reaction / methods

Substances

  • Glial Fibrillary Acidic Protein
  • P2ry1 protein, rat
  • P2ry2 protein, rat
  • RNA, Messenger
  • Receptors, Adrenergic, beta
  • Receptors, Purinergic P2
  • Receptors, Purinergic P2Y1
  • Receptors, Purinergic P2Y2