Abstract
Purpose:
Loss of corneal nerves can lead to a loss of sensation that in turn may result in damage to the cornea. The purpose of this research is to investigate the interaction between innervation and the development of the cornea, with the goal of understanding the function of corneal nerves in both healthy and damaged corneas. Little is known about the mechanisms involved in the interaction between nerves and corneal cells during development. Corneal innervation is necessary for the perception of pain and for the overall maintenance of the cornea through the release of trophic factors; however, the mechanisms involved are unclear. We have tested how the neuropeptide, substance P (SP), affects the expression of a group of genes that, based on previous experiments, may be involved in the interaction between corneal nerves and epithelial cells
Methods:
hCTEpi cells were treated with SP at concentrations of 1 nM, 100 nM, 1µM and control for 2, 10 and 60 minutes. Following treatment, the cells had a recovery period in normal media for 60 minutes. cDNA was synthesized was from total mRNA. qRT-PCR was performed for candidate genes to analyze its expression after treatment. Candidate genes were selected from previous studies taking into account their expression pattern, their function and the changes in expression that they showed during different stages of innervation in development.<br />
Results:
SP treatment resulted in a down-regulation of the genes FGFBP, NET1 and KRT5. This effect was both dose and time dependent as the greatest degree of down-regulation was observed at the lower dose (1nM) and the longest treatment time (60 min).<br />
Conclusions:
These studies show that physiological concentrations of the neuropeptide SP, a molecule known to be released by corneal nerves, affect gene expression in the hTCEpi corneal epithelial cell line. However, while SP does affect the expression of these genes, their exact function as well as the mechanisms involved in their down-regulation, remains to be determined.