Species variation and spatial differences in mucin expression from corneal epithelial cells.
Mucins are large glycoproteins expressed by epithelial cells of both the conjunctiva and cornea, and principle components of the glycocalyx. They are thought to play an important role in determining the interactions between the cornea/conjunctiva and the overlying tear film. The purpose of this study was to characterize the membrane-associated corneal mucin expression pattern from multiple species commonly used in ophthalmic research and drug development to better define the biochemical attributes of the ocular surface. Humans, rhesus macaques and dogs were found to have a very similar pattern of mucin expression, with mucin 16 (MUC16) being the most prevalent mucin transcript. In contrast, the rabbit had a unique mucin expression pattern with all mucin transcripts expressed at relatively similar levels. To determine if there were spatial differences in expression, peripheral and central corneal epithelium were individually isolated and evaluated for mucin expression. In all species examined, MUC1, MUC4 and MUC16 had higher peripheral corneal expression when compared with central, which reached statistical significance in MUC1 (rhesus and dog). The data demonstrated variation in corneal epithelial membrane-associated mucin expression between species, with the rabbit having a distinct expression pattern. These differences may be reflective of the environment, pathogen exposure or tear film dynamics of the respective species. The species differences, as well as regional mucin expression patterns, characterized in this study further define the biochemical composition of the ocular surface and may play an important role in tear film stability.
William R. Pritchard VMTH, School of Veterinary Medicine, University of California, Davis, United States; School of Veterinary Medicine, Department of Surgical and Radiological Sciences, University of California Davis, Davis, United States.
Brian C
BC
Leonard
School of Veterinary Medicine, Department of Surgical and Radiological Sciences, University of California Davis, Davis, United States; Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, United States; CONACYT-Instituto de Física, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, 78000 San Luis Potosí, S.L.P., Mexico.
Bernardo
B
Yañez-Soto
The Ocular Surface Institute, College of Optometry, University of Houston, Houston, TX, United States.
Vijay Krishna
VK
Raghunathan
Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, United States.
Nicholas L
NL
Abbott
School of Veterinary Medicine, Department of Surgical and Radiological Sciences, University of California Davis, Davis, United States; Ophthalmology & Vision Science, School of Medicine, University of California, Davis, United States. Electronic address: cjmurphy@ucdavis.edu.
Christopher J
CJ
Murphy
D000818:Animals; D015153:Blotting, Western; D004285:Dogs; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008253:Macaca mulatta; D018396:Mucin-1 / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D013666:Tears / Q000378:metabolism*
D018396:Mucin-1; D012333:RNA, Messenger
Cornea; Mucin; Ocular surface; Ophthalmology