Abstract
Abstract: :
Purpose: To study the effect of 24-hours low oxygen transmissible RGP contact lens wear on the expression of Muc1 in the rabbit corneal epithelium. Methods: Rigid gas permeable (RGP) lenses (Dk/t=10) were randomly fitted in one eye of each New Zealand White rabbit (n=7) for 24-hours, the non-lens wearing eye acted as control. 1) Immunocytochemistry: Frozen 8µm corneal and conjunctival sections were treated with neuraminidase and stained with Anti-Muc1 antibody (Signet Pathology Systems Inc., Dedham, MA). In Addition, Anti-Sialylated Lea antibody (OEM concepts, Toms River, NJ) was used for detection of salivary mucin. 2) Western Blotting: Immediately following humane sacrifice, epithelial cells were scraped from the cornea and pooled in a homogenized buffer (n=4). Protein concentrations were measured by modification of the Lowry method for use with Thiols, followed by SDS-polyacrylamide (6%) gel electrophoresis. Proteins were then transferred to a nitrocellulose membrane, and stained with Anti-Muc1 antibody. The X-ray film was digitally scanned on the computer and the intensity of each Muc1 band was quantified. Results: In the normal control, Muc1 was generally expressed as expected in the superficial and outer wing cell layers of the corneal epithelium. In the test lens wearing eyes the staining pattern was similar; however, the intensity was visibly reduced. Western blotting showed that Muc1 was reduced in the lens wearing group to 24% of control. MW of rabbit Muc1 was determined to be 127kDa. Sialylated Lea antigen was exclusively located on the superficial cell layers of the conjunctival epithelium. Conclusion: Low oxygen transmissible RGP lens wear significantly decreased the immunocytological detectability of Muc1 in the corneal epithelium. Lens mediated decreased availability of Muc1 might contribute to the significantly enhanced bacterial binding of Pseudomonas aeruginosa to the corneal epithelium known to occur by wear of this test lens in the rabbit (Ophthalmology 1994;101:371-388). Further studies are needed to elaborate on the effect of diminished Muc1 expression during lens wear in the corneal epithelium.
Keywords: 367 contact lens • 421 glycoconjugates/glycoproteins • 372 cornea: epithelium