Human aqueous humor phosphatase activity in cataract and glaucoma.
OBJECTIVE
To investigate the presence and activity of protein phosphatase-2A (PPase2A), protein phosphatase-2C (PPase2C), and protein tyrosine phosphatases (PTPs) in the human aqueous humor (AH) of patients with primary open-angle glaucoma (POAG) and cataract and to study the correlation between these phosphatases and the redox state of the AH.


METHODS
Eighty-six cataract patients and 29 POAG patients who were scheduled for cataract surgery with or without glaucoma surgery were enrolled in the study. PPase2A, PPase2C, and PTPs levels in AH were measured by enzyme-linked immunosorbent assays, Western blot analyses, and spectral


METHODS
The redox state was measured by spectral and fluorescent methods.


RESULTS
Phosphatase activity-positive results were significantly higher in AH samples from the POAG group (PP2A χ(2)(1) = 11.754, P < 0.01; PP2C χ(2)(1) = 8.754, P < 0.01; PTP χ(2)(1) = 11.073, P < 0.01). Western blot analysis revealed higher PP2C levels in the AH of glaucoma patients compared with PP2C levels in the AH of cataract patients (P = 0.012). Both oxidized/reduced glutathione ratios and superoxide dismutase levels in the AH were significantly higher in the glaucoma group than in the cataract group. Finally significant correlations were found between PP2A and PP2C, PP2A and PTP, and total antioxidant activity and PTP levels.


CONCLUSIONS
There is a statistically significant difference between phosphatase levels in the AH of POAG patients and cataract patients. The phosphatase content of the AH represents tissue pathology, but their presence in the AH may be attributed to cell debris or to active signaling to other molecular events.
Department of Clinical Pharmacology, The Faculty of Health Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel.
Galina
G
Latarya
Ahmad
A
Mansour
Irena
I
Epstein
Daniel
D
Cotlear
Joseph
J
Pikkel
Shmuel
S
Levartovsky
Michael
M
Yulish
Elie
E
Beit-Yannai
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000737:chemistry / Q000201:enzymology*; D015153:Blotting, Western; D002386:Cataract / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005902:Glaucoma, Open-Angle / Q000378:metabolism*; D005978:Glutathione / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D010749:Phosphoprotein Phosphatases / Q000032:analysis / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000032:analysis / Q000378:metabolism*; D000071636:Protein Phosphatase 2C; D017027:Protein Tyrosine Phosphatases / Q000032:analysis / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000032:analysis
D013482:Superoxide Dismutase; C000607456:PPM1A protein, human; C000607457:PPM1B protein, human; C000607460:PPM1G protein, human; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D017027:Protein Tyrosine Phosphatases; D005978:Glutathione