title: Expression of cholecystokinin, gastrin, and their receptors in the mouse cornea.
abstract: OBJECTIVE
  Cholecystokinin (CCK) is a neuropeptide that has been identified in trigeminal ganglion neurons. Gastrin (GAST) is a related peptide never explored in the cornea. The presence and role of both gastrointestinal peptides in the cornea and corneal sensory neurons remain to be established. We explored here in mice whether CCK, GAST, and their receptors CCK1R and CCK2R are expressed in the corneal epithelium and trigeminal ganglion neurons innervating the cornea.
  
  
  METHODS
  We used RT-PCR analysis to detect mRNAs of CCK, GAST, CCK1R, and CCK2R in mouse cornea epithelium, trigeminal ganglia, and primary cultured corneal epithelial cells. Immunofluorescence microscopy was used to localize these peptides and their receptors in the cornea, cultured corneal epithelial cells, and corneal nerves, as well as in the cell bodies of corneal trigeminal ganglion neurons identified by retrograde labeling with Fast Blue.
  
  
  RESULTS
  Mouse corneal epithelial cells in the cornea in situ and in cell cultures expressed CCK and GAST. Only the receptor CCK2R was found in the corneal epithelium. In addition, mouse corneal afferent sensory neurons expressed CCK and GAST, and the CCK1R receptors.
  
  
  CONCLUSIONS
  The presence of CCK, GAST, and their receptors in the mouse corneal epithelium, and in trigeminal ganglion neurons supplying sensory innervation to the cornea, opens the possibility that these neuropeptides are involved in corneal neurogenic inflammation and in the modulation of repairing/remodeling processes following corneal injury.
authors.affiliation: Fundación de Investigación Oftalmológica, Instituto Fernandez-Vega, Oviedo, Spain.
authors.forename: Ana F
authors.initials: AF
authors.lastname: Gonzalez-Coto
authors.forename: Carlos
authors.initials: C
authors.lastname: Alonso-Ron
authors.forename: Ignacio
authors.initials: I
authors.lastname: Alcalde
authors.forename: Juana
authors.initials: J
authors.lastname: Gallar
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Meana
authors.forename: Jesús
authors.initials: J
authors.lastname: Merayo-Lloves
authors.forename: Carlos
authors.initials: C
authors.lastname: Belmonte
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002766:Cholecystokinin / Q000096:biosynthesis / Q000235:genetics*; D003315:Cornea / Q000294:innervation / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism; D005755:Gastrins / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012313:RNA / Q000235:genetics; D043887:Receptor, Cholecystokinin B / Q000096:biosynthesis / Q000235:genetics; D011949:Receptors, Cholecystokinin / Q000096:biosynthesis / Q000235:genetics; D014276:Trigeminal Nerve / Q000378:metabolism*
chemical_list: D005755:Gastrins; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D012313:RNA; D002766:Cholecystokinin
keywords: CCK; CCK1R; CCK2R; cornea; gastrin; mouse; sensory innervation