Abstract
Purpose :
Dry eye disease (DED) leads to changes in corneal nerves, which originate from sensory neurons in the trigeminal ganglion (TG). Satellite glial cells (SGS) are the principle glial cells in TG and play a critical role in regulating sensory neuron activities. In this study, we report changes in neuro-peptide expression and SGC activation in TG after acute and chronic DED.
Methods :
Acute DED was induced in female 8-week old C57BL/6 mice by placing them in a controlled environment chamber (CEC) for 1 week. Chronic DED was induced by placing mice in in CEC for 2 weeks and then transferring to standard vivarium for 4 weeks. TG were harvested and the mRNA and protein expression of neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) was detected using RT-PCR and ELISA. SGC were isolated from TG and cultured for 7 days. The expression of glial fibrillary acidic protein (GFAP, marker for SGC activation) in TG lysates and cultured SGC was determined using Western Blot.
Results :
During acute DED, SP expression in TG increased significantly (2 fold , P=0.045) while CGRP levels were unchanged; GFAP protein expression increased significantly in both TG (1.46 fold, P=0.031) and cultured SGCs (2.37 fold, P=0.0095), compared to age-matched mice without DED. During chronic DED, CGRP expression in TG decreased by 49.9% (P=0.026) and GFAP level decreased by 29.8%, but GFAP level did not reach statistical significance.
Conclusions :
Acute and chronic dry eye disease leads to differential changes in neuro-peptide expression by sensory neurons in the trigeminal ganglion. In addition, satellite glial cells are activated in acute DED.
This is a 2020 ARVO Annual Meeting abstract.