Abstract
Purpose :
To investigated the effects of silk fibroin on the cornea, conjunctiva, and lacrimal gland in a dry eye mouse model.
Methods :
The experimental dry eye mouse model was subcutaneous injections of scopolamine (muscarinic receptor blocker) and exposure to an air draft at an ambient humidity of 30-40% for 18 hours per day for 10 days on the 12- to 16-week-old NOD.B10.H2b mice. Tear volume and corneal smoothness were measured at 3, 5, 7 and 10 days after the instillation of phosphate buffered saline (PBS group) or silk fibroin (Silk group; 1 or 5 mg/ml). The corneal detachment and conjunctival goblet cell density were sectioned and stained with hematoxylin and eosin (H&E) and periodic acid Schiff (PAS) in the cornea and conjunctiva. The expression of inflammatory markers (i.e., TNF-α, MMP-2, MMP-9, ICAM-1, and VCAM-1) was detected by immunohistochemistry in the lacrimal gland. All data were statistically processed using the SPSS version 18.0.
Results :
The Silk group (1 or 5 mg/ml), tear production was increased by up to 2.1-fold, and corneal smoothness was improved to 46.2% and 53.8%, respectively, compared to the PBS group (P < 0.05). The detachment of the corneal epithelial cells was reduced by 90.9% in the silk group compared to the PBS group, and the conjunctival goblet cell density was significantly recovered to 1.4-fold and 1.7-fold, respectively, compared to the PBS group (P < 0.05). The expression of inflammatory factors was decreased in the lacrimal gland of the silk group compared to the PBS group.
Conclusions :
These results show that silk fibroin improved on the cornea, conjunctiva, and lacrimal gland in the dry eye mouse model. These findings suggest that silk fibroin has anti-inflammatory effects in experimental model of dry eye.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.