Purpose: To investigate the effects and possible mechanisms of serine protease inhibitor A3K (SERPINA3K) on the formation of ocular surface squamous metaplasia in a mouse dry eye model induced by topical benzalkonium chloride (BAC).
Methods: The eye drops containing SERPINA3K were topically administered during the induction of BAC-induced dry eye. The clinical indications of dry eye were evaluated on day (D)16, including tear break-up time (BUT), tear volume, corneal fluorescein staining, and inflammatory index. Global specimens were collected on D16 and the following examinations were performed: histologic investigation, immunostaining of cytokeratin 10 (K10), p63 and Ki67 in the cornea, and Western blot analysis of tumor necrosis factor-α (TNF-α).
Results: Serine protease inhibitor A3K suppressed the formation of BAC-induced dry eye, presenting with longer BUTs, lower corneal fluorescein staining scores, and inflammatory index, while no significant changes in tear volume. It also reduced the severity of abnormal differentiation and proliferation on ocular surface with lower expressions of K10, p63, and Ki67, and retained the number of goblet cells in the conjunctival fornix. Serine protease inhibitor A3K significantly decreased the levels of TNF-α in the cornea.
Conclusions: Topical application of SERPINA3K ameliorated the severity of ocular surface squamous metaplasia and suppressed the formation of BAC-induced dry eye.
Keywords: dry eye; inflammation; serine proteinase inhibitor; squamous metaplasia.
Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.