P2Y2 nucleotide receptor-mediated responses in brain cells

Mol Neurobiol. 2010 Jun;41(2-3):356-66. doi: 10.1007/s12035-010-8115-7. Epub 2010 Apr 13.

Abstract

Acute inflammation is important for tissue repair; however, chronic inflammation contributes to neurodegeneration in Alzheimer's disease (AD) and occurs when glial cells undergo prolonged activation. In the brain, stress or damage causes the release of nucleotides and activation of the G(q) protein-coupled P2Y(2) nucleotide receptor subtype (P2Y(2)R) leading to pro-inflammatory responses that can protect neurons from injury, including the stimulation and recruitment of glial cells. P2Y(2)R activation induces the phosphorylation of the epidermal growth factor receptor (EGFR), a response dependent upon the presence of a SH3 binding domain in the intracellular C terminus of the P2Y(2)R that promotes Src binding and transactivation of EGFR, a pathway that regulates the proliferation of cortical astrocytes. Other studies indicate that P2Y(2)R activation increases astrocyte migration. P2Y(2)R activation by UTP increases the expression in astrocytes of alpha(V)beta(3/5) integrins that bind directly to the P2Y(2)R via an Arg-Gly-Asp (RGD) motif in the first extracellular loop of the P2Y(2)R, an interaction required for G(o) and G(12) protein-dependent astrocyte migration. In rat primary cortical neurons (rPCNs) P2Y(2)R expression is increased by stimulation with interleukin-1beta (IL-1beta), a pro-inflammatory cytokine whose levels are elevated in AD, in part due to nucleotide-stimulated release from glial cells. Other results indicate that oligomeric beta-amyloid peptide (Abeta(1-42)), a contributor to AD, increases nucleotide release from astrocytes, which would serve to activate upregulated P2Y(2)Rs in neurons. Data with rPCNs suggest that P2Y(2)R upregulation by IL-1beta and subsequent activation by UTP are neuroprotective, since this increases the non-amyloidogenic cleavage of amyloid precursor protein. Furthermore, activation of IL-1beta-upregulated P2Y(2)Rs in rPCNs increases the phosphorylation of cofilin, a cytoskeletal protein that stabilizes neurite outgrowths. Thus, activation of pro-inflammatory P2Y(2)Rs in glial cells can promote neuroprotective responses, suggesting that P2Y(2)Rs represent a novel pharmacological target in neurodegenerative and other pro-inflammatory diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Amino Acid Sequence
  • Amyloid beta-Protein Precursor / metabolism
  • Animals
  • Brain / cytology*
  • Brain / metabolism
  • Cytoskeleton / metabolism
  • Inflammation / metabolism
  • Microvessels / metabolism
  • Molecular Sequence Data
  • Neuroglia / cytology
  • Neuroglia / metabolism*
  • Neurons / cytology
  • Neurons / metabolism*
  • Protein Structure, Secondary
  • Receptors, Purinergic P2 / chemistry
  • Receptors, Purinergic P2 / genetics
  • Receptors, Purinergic P2 / metabolism*
  • Receptors, Purinergic P2Y2
  • Signal Transduction / physiology

Substances

  • Amyloid beta-Protein Precursor
  • P2ry2 protein, rat
  • Receptors, Purinergic P2
  • Receptors, Purinergic P2Y2