Cytoprotective Effect of Lacritin on Human Corneal Epithelial Cells Exposed to Benzalkonium Chloride In Vitro. (June 2014)

• Record Type: Journal Article
• Authors: Feng, Mary M.; Baryla, Julia; Liu, Hong; Laurie, Gordon W.; McKown, Robert L.; Ashki, Negin; Bhayana, Dinesh; Hutnik, Cindy M. L.
• Is Part Of: Current eye research. Volume 39:Number 6(2014:Jun.)
• Page Start: 604
• Page End: 610
• Publication Date: 2014-06
• Subjects: Ophthalmology -- Periodicals; Eye -- Diseases -- Periodicals; Ophthalmology -- Periodicals; 573.88
• DOI: 10.3109/02713683.2013.859275
• Languages: English
• ISSNs: 0271-3683

Abstract

<abstract> <title>Abstract</title> <p> <italic>Purpose</italic>: Benzalkonium chloride (BAK) is the most commonly found preservative in eye drops, and has been shown to cause ocular surface inflammation and toxicity. Lacritin is a human tear glycoprotein secreted from the lacrimal glands that has been found to be cytoprotective. This study was designed to determine if the presence of lacritin confers protection to a cultured human corneal epithelial (HCE) cell line, CRL-11515, and primary HCE cells after exposure to the ocular preservative agent BAK.</p> <p> <italic>Materials and methods</italic>: Recombinant human lacritin was cloned into intein fusion vectors, expressed in <italic>E. coli</italic>, and purified on chitin beads and DEAE Sepharose. Metabolic curves were established using the MTT assay after exposure of sub-confluent CRL-11515 cells to BAK or lacritin. Western blot analysis of lipidated LC3 (LC3-II) provided a measure of autophagy in CRL-11515 cells exposed to lacritin and/or BAK.</p> <p> <italic>Results</italic>: BAK reduced CRL-11515 cellular metabolic activity in a time- and dose-dependent manner. BAK-induced cellular stress was evident by elevated autophagy that increased with rising concentrations of BAK compared to control (<italic>p</italic> < 0.05). Lacritin increased HCE cell proliferation at an optimal dose of 1 nM. Preconditioning HCE cells with 1 nM lacritin for 24 h prior to BAK exposure significantly dampened levels of LC3-II (<italic>p</italic> < 0.05) and promoted a significant increase in cellular metabolic activity (<italic>p</italic> < 0.01) compared to BAK alone.</p> <p> <italic>Conclusions</italic>: These results suggest lacritin protects cultured HCE cells stressed with BAK. Lacritin may have the potential to be used as a topical adjunctive therapy in eyes chronically exposed to BAK.</p> </abstract>