Central CRTH2, a second prostaglandin D2 receptor, mediates emotional impairment in the lipopolysaccharide and tumor-induced sickness behavior model

J Neurosci. 2014 Feb 12;34(7):2514-23. doi: 10.1523/JNEUROSCI.1407-13.2014.

Abstract

Chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2) is a second prostaglandin D2 receptor involved in mediating the allergic response; however, its central function is not yet known. Here, we demonstrate that central CRTH2 mediates emotional impairment. Lipopolysaccharide (LPS)-induced decreases in social interaction and novel exploratory behavior were observed in wild-type (CRTH2(+/+)) mice but not CRTH2-deficient (CRTH2(-/-)) mice, but both genotypes showed hypolocomotion and anorexia following LPS injection. Tumor (colon 26) inoculation, a more pathologically relevant model, induced decreases in social interaction and novel exploratory behavior in CRTH2(+/+), but not CRTH2(-/-) mice. In addition, the CRTH2 antagonists including clinically available ramatroban reversed impaired social interaction and novel exploratory behavior after either LPS or tumor inoculation in CRTH2(+/+) mice. Finally, LPS-induced c-Fos expression in the hypothalamic paraventricular nucleus (PVN) and central amygdala (CeA) was selectively abolished in CRTH2(-/-) mice. These results show that CRTH2 participates in LPS-induced emotional changes and activation in the PVN and CeA. Our study provides the first evidence that central CRTH2 regulates specific emotional behaviors, and that CRTH2 antagonism has potential as a therapeutic target for behavioral symptoms associated with tumors and infectious diseases.

Keywords: c-Fos; cyclooxygenase; lipopolysaccharide; prostaglandin D2 receptor; social interaction; tumor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / metabolism*
  • Disease Models, Animal
  • Illness Behavior / physiology*
  • Immunohistochemistry
  • Lipopolysaccharides / toxicity
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Neoplasms, Experimental / psychology
  • Receptors, Immunologic / metabolism*
  • Receptors, Prostaglandin / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stress, Psychological / metabolism*

Substances

  • Lipopolysaccharides
  • Receptors, Immunologic
  • Receptors, Prostaglandin
  • prostaglandin D2 receptor