Abstract
Purpose :
The vitamin D receptor (VDR) and vitamin D metabolic associated enzymes have been determined in various kinds of cells in both mouse eyes and human eyes. In this study, we examined the effects of VDR knockout on the pathological changes of meibomian gland (MG), eyelid tissue, and the secretion of tear fluid.
Methods :
Eyelids of VDR knockout mice aged 3 months (n=10) and 7 months (n=10) were investigated and compared with 20 normal eyelids from age-matched wild type C57/B6J mice. Microscopy examination and fluorescein staining were performed to check the ocular surface. Cotton thread test, MILLIPLEX® MAP and qRT-PCR were used to analyze the tear fluid and eyelid tissue. We also examined the haemotoxylin and eosin staining of the eyelid and lacrimal gland (LG), and observed the immunofluorescent staining for cytokeratins CK1, CK5, CK6.
Results :
Keratinous cysts of MG, partial dropout of MG, and thinning and whitening of the cilia were shown in VDR knockout mice aged 3 months or 7 months. With aging, MG cysts progressively grew while the obstruction, lump or nodule of MG on the conjunctival surface can be observed. The secretion of tear fluid from VDR knockout mice significantly increased (P<0.05) and mRNA expression of mucin and some inflammatory markers in eyelid tissue were also upregulated significantly (P<0.05). The lid margin of VDR knockout mice showed more expression of CK1. In addition, there were no significant differences of corneal fluorescein staining or haemotoxylin and eosin staining of the lacrimal gland (LG).
Conclusions :
Vitamin D receptor knockout influences the pathogenesis of MG, hyper-keratinization of the eyelid, and secretion of tear fluid.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.