Expression of the receptor tyrosine kinases, epidermal growth factor receptor, ErbB2, and ErbB3, in human ocular surface epithelia.
OBJECTIVE
To investigate the distribution and relative level of expression of the receptor tyrosine kinases, epidermal growth factor receptor (EGFR), ErbB2 and ErbB3, in human ocular surface epithelia.


METHODS
Immunofluorescent staining was performed to identify expression of the EGFR, ErbB2 and ErbB3 in the corneal, limbal and conjunctival epithelium in tissue sections and impression cytologies taken from normal human eyes. Western blotting was undertaken to confirm the results of immunofluorescent staining.


RESULTS
The three receptor tyrosine kinases, EGFR, ErbB2 and ErbB3, were detected in human corneal, limbal and conjunctival epithelia by immunofluorescent staining. Strong staining for the EGFR was observed in the basal epithelial cells at all 3 sites and throughout the corneal epithelium. Minimal or no staining for the EGFR was observed in the superficial conjunctival and limbal epithelia. The strongest staining for ErbB2 and ErbB3 was observed in the superficial ocular surface epithelium. All three receptors were detected in the corneal, limbal and conjunctival epithelium by western blot.


CONCLUSIONS
EGFR, ErbB2 and ErbB3 are expressed by the ocular surface epithelia. EGFR is preferentially expressed by the basal epithelial cells that have the greatest proliferative potential. In contrast, ErbB2 and ErbB3 are preferentially expressed by the superficial differentiated ocular surface epithelia.
Liu
Z
Z
Ocular Surface and Tear Center Bascom Palmer Eye Institute, University of Miami School of Medicine, Florida 33136, USA.
Carvajal
M
M
Carraway
C A
CA
Carraway
K
K
Pflugfelder
S C
SC
D000818:Animals; D015415:Biomarkers; D015153:Blotting, Western; D003228:Conjunctiva / Q000166:cytology / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D020893:Receptor, ErbB-3 / Q000378:metabolism*
D015415:Biomarkers; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3