PURPOSE: To determine the protein and mRNA expression of p53, p63, and p73 in 
central and peripheral human corneal endothelial cells. Since these proteins are 
known to be involved in the regulation of cell division, this study seeks 
information about their influence in regulating cell proliferation in the human 
corneal endothelium.
METHODS: Human donor corneas were separated into central and peripheral 
sections. The endothelial tissue from these samples was dissected and samples 
were analyzed for mRNA transcription of p53, transactivating p63 (TAp63), delta 
N p63 (DeltaNp63), transactivating p73 (TAp73), and delta N p73 (DeltaNp73) via 
the reverse transcriptase-polymerase chain reaction (RT-PCR). Additional samples 
were analyzed for p53, p63, and p73 protein expression via SDS-PAGE, western 
blotting, and immunodetection. Frozen corneal sections were immunostained for 
p53 and analyzed via fluorescence microscopy.
RESULTS: p53 and TAp63 mRNA and protein expression were detected in central and 
peripheral human corneal endothelium. p53 and TAp63 protein expression were 
greater in central than in peripheral tissue. DeltaNp63 and all isoforms of p73 
were not detected in either central or peripheral corneal endothelium.
CONCLUSIONS: p53 is expressed in both peripheral and central human corneal 
endothelium, although it is more highly expressed in the central endothelium. 
Similarly, TAp63 is more highly expressed in central rather than in peripheral 
endothelium. This suggests that the peripheral endothelium may have more 
potential for cell division than the central endothelium. DeltaNp63, a stem cell 
marker, was not detected in the corneal endothelium. Neither the TAp73 nor the 
DeltaNp73 isoforms were detected in either central or peripheral human corneal 
endothelium.