The eicosanoid, 15-(S)-HETE, stimulates secretion of mucin-like glycoprotein by the corneal epithelium.

Abstract

PURPOSE:

The eicosanoid, 15-(S)-hydroxyeicosa-5Z, 8Z-11Z, 13E-tetraenoic acid (15-(S)-HETE), is known to stimulate production of mucin glycoprotein by airway epithelium. This study investigated the effect of 15-(S)-HETE on the mucin glycoprotein secretion by the corneal epithelium.

METHODS:

To determine the effect of dose, corneas of anesthetized New Zealand White rabbits were treated with 50, 500, or 5,000 nM 15-(S)-HETE in artificial tears for 120 minutes. To determine the time to onset of the response, corneas were treated with 500 or 1,000 nM 15-(S)-HETE in balanced salt solution for periods ranging from 5 to 120 minutes. Corneas were fixed for electron microscopy in fixative containing 0.5% cetylpyridinium chloride (CPC) to stabilize the layer of mucin-like glycoprotein on the corneal surface. The mucin layer thickness was measured by image analysis of electron micrographs.

RESULTS:

The layer of CPC-fixed mucin-like glycoprotein on the surface of control corneas was 0.46 +/- 0.04 microm thick. After treatment with 15-(S)-HETE, the thickness of the mucin layer increased to 0.64 +/- 0.1 microm at 50 or 5,000 nM HETE and as much as 1.02 +/- 0.2 microm in response to 500 nM HETE. Mucin thickness reached a statistical maximum of 0.59 +/- 0.1 microm after only 5 minutes of exposure to 500 or 1,000 nM HETE.

CONCLUSIONS:

Exposure of the cornea to 15-(S)-HETE causes a rapid-onset increase in the thickness of a layer of mucin-like glycoprotein on the surface of the corneal epithelium. This supports previous reports that corneal epithelial cells produce mucin and suggests that treatment with topical 15-(S)-HETE may be effective in treating ocular surface mucin deficiency in dry eye syndrome.

• Authors: R S Jackson 2nd, S J Van Dyken, M D McCartney, J L Ubels
• Journal: Cornea (Cornea) Vol. 20 Issue 5 Pg. 516-21 (Jul 2001) ISSN: 0277-3740 [Print] United States
• PMID: 11413409 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Eye Proteins
• Fluoresceins
• Hydroxyeicosatetraenoic Acids
• Mucins
• 6-carboxyfluorescein
• 15-hydroxy-5,8,11,13-eicosatetraenoic acid

Topics

• Animals
• Biological Transport
• Epithelium, Corneal (drug effects, metabolism, ultrastructure)
• Eye Proteins (metabolism)
• Fluoresceins (pharmacokinetics)
• Hydroxyeicosatetraenoic Acids (pharmacology)
• Mucins (metabolism)
• Rabbits