The enteric nervous system of P2Y13 receptor null mice is resistant against high-fat-diet- and palmitic-acid-induced neuronal loss

Purinergic Signal. 2014 Sep;10(3):455-64. doi: 10.1007/s11302-014-9408-5. Epub 2014 Feb 9.

Abstract

Gastrointestinal symptoms have a major impact on the quality of life and are becoming more prevalent in the western population. The enteric nervous system (ENS) is pivotal in regulating gastrointestinal functions. Purinergic neurotransmission conveys a range of short and long-term cellular effects. This study investigated the role of the ADP-sensitive P2Y13 receptor in lipid-induced enteric neuropathy. Littermate P2Y13 (+/+) and P2Y13 (-/-) mice were fed with either a normal diet (ND) or high-fat diet (HFD) for 6 months. The intestines were analysed for morphological changes as well as neuronal numbers and relative numbers of vasoactive intestinal peptide (VIP)- and neuronal nitric oxide synthase (nNOS)-containing neurons. Primary cultures of myenteric neurons from the small intestine of P2Y13 (+/+) or P2Y13 (-/-) mice were exposed to palmitic acid (PA), the P2Y13 receptor agonist 2meSADP and the antagonist MRS2211. Neuronal survival and relative number of VIP-containing neurons were analysed. In P2Y13 (+/+), but not in P2Y13 (-/-) mice, HFD caused a significant loss of myenteric neurons in both ileum and colon. In colon, the relative numbers of VIP-containing submucous neurons were significantly lower in the P2Y13 (-/-) mice compared with P2Y13 (+/+) mice. The relative numbers of nNOS-containing submucous colonic neurons increased in P2Y13 (+/+) HFD mice. HFD also caused ileal mucosal thinning in P2Y13 (+/+) and P2Y13 (-/-) mice, compared to ND fed mice. In vitro PA exposure caused loss of myenteric neurons from P2Y13 (+/+) mice while neurons from P2Y13 (-/-) mice were unaffected. Presence of MRS2211 prevented PA-induced neuronal loss in cultures from P2Y13 (+/+) mice. 2meSADP caused no change in survival of cultured neurons. P2Y13 receptor activation is of crucial importance in mediating the HFD- and PA-induced myenteric neuronal loss in mice. In addition, the results indicate a constitutive activation of enteric neuronal apoptosis by way of P2Y13 receptor stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diet, High-Fat / adverse effects*
  • Enteric Nervous System / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myenteric Plexus / drug effects
  • Myenteric Plexus / metabolism
  • Myenteric Plexus / pathology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Organ Culture Techniques
  • Palmitic Acid / toxicity*
  • Receptors, Purinergic P2 / deficiency*

Substances

  • P2ry13 protein, mouse
  • Receptors, Purinergic P2
  • Palmitic Acid