Expression of cholecystokinin, gastrin and their receptors in the mouse cornea
Authors
Ana F. Gonzalez-Coto, Carlos Alonso-Ron, Ignacio Alcalde, Juana Gallar, Álvaro Meana, Jesús Merayo-Lloves, Carlos Belmonte
Institution
Univ Oviedo
Country
Spain
Year
2014
Journal
IOVS
Abstract
Purpose. 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 in the
trigeminal ganglion neurons innervating the cornea. Methods. RT-PCR analysis was
used 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 both 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 both CCK
and GAST, and the CCK1R and CCK2R 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.