[Functional significance of adenosine receptors in the eye and their dysregulation in pseudoexfoliation syndrome].
BACKGROUND
Adenosine regulates many physiologic processes, such as aqueous humor secretion and intraocular pressure, via activation of its receptors. We investigated the expression of the receptor isoforms in eyes with PEX syndrome, which is associated with anterior chamber hypoxia and elevated intraocular pressure.


METHODS
The mRNA and protein expression of the adenosine receptor subtypes in anterior segment tissues of patients with PEX syndrome, glaucomas, and normal control eyes were analyzed comparatively.


RESULTS
Whereas the receptor subtypes A1, A2a, and A2b displayed no differential expression between PEX and control tissues, expression of the A3 adenosine receptor was consistently enhanced in the nonpigmented ciliary epithelium of all PEX eyes, independent of the presence of glaucoma, compared to normal and glaucomatous control eyes.


CONCLUSIONS
Considering the known role of the A3 adenosine receptor in modulating aqueous humor secretion, its selective upregulation in the ciliary epithelium may confer cytoprotection and be accessible to therapeutic intervention in PEX patients.
Schlötzer-Schrehardt
U
U
Augenklinik der Friedrich-Alexander-Universität Erlangen-Nürnberg. ursula.schloetzer@augen.imed.uni-erlangen.de
Zenkel
M
M
Hofmann-Rummelt
C
C
Kruse
F E
FE
Naumann
G O
GO
D000368:Aged; D019573:Epithelium, Corneal / Q000378:metabolism*; D017889:Exfoliation Syndrome / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D005901:Glaucoma / Q000378:metabolism*; D006801:Humans; D008297:Male; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D014018:Tissue Distribution
D018047:Receptors, Purinergic P1