行政院國家科學委員會專題研究計畫期中進度報告:Muc5 AC-Diphtheria Toxin基因轉殖鼠之黏膜黏液素表現(1/3)

Abstract

The tear film is composed of an outer lipid layer and an inner aqueous phase, which contains a variety of mucin, adjacent to the glycocalyx of the apical cells of the epithelium. Mucins are a heterogenous group of O-linked glycoproteins, synthesized and secreted primarily by goblet cells, which coat and protect mucosal epithelia. Ocular surface mucin adheres to the glycocalyces of conjunctival and corneal epithelial cells and enhances wetability of the cornea by serving as an interface between the hydrophobic corneal epithelium and the aqueous tear fluid.1,2 Therefore, mucin can stabilize the tear film, provide a smooth and refractive surface of high optical quality over the cornea, lubricate the corneal and conjunctival epithelial surfaces during eye blinking, and prevent desiccation of the ocular surface through water retention. It also serves as a barrier to microbial invasion and shields conjunctival and corneal cells from surface debris and noxious substances.3,4 As a consequence of their extensive glycosylation, mucins offer a wide range of terminal carbohydrate-related epitopes that can act as receptors for ligands expressed in certain microorganisms and viruses. Consequently, ocular mucins may also prevent pathogen penetrance by inhibiting bacterial adhesion to the ocular surface epithelium.