Matrix metalloproteinases and their tissue inhibitors in aqueous humor of patients with primary open-angle glaucoma, exfoliation syndrome, and exfoliation glaucoma.
OBJECTIVE
To study extracellular matrix (ECM) metabolism by matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in aqueous humor (AH) samples collected from primary open-angle glaucoma (POAG), exfoliation syndrome (EXS), and exfoliation glaucoma (EXG) in relation to samples derived from cataract control patients.


METHODS
Seventy-one AH samples were collected during cataract extraction and trabeculectomy. The expression and molecular forms of MMP-2, -8, -9, -13, and -14 and tissue inhibitor of metalloproteinases-1 and -2 (TIMPs) were analyzed by Western immunoblotting. Gelatinase and collagenase activities were studied by zymography and type I collagen degradation assays, respectively. MMP-2 and TIMP-2 concentrations were measured by ELISA assays.


RESULTS
By Western immunoblotting all the studied MMPs were mainly in their latent form in all diagnostic groups. Zymography demonstrated that MMP-2 represents the major gelatinase in AH. Similarly, type I collagenolytic activity was low and similar in cataract and glaucoma samples. In ELISA measurements the TIMP-2 levels were significantly elevated in glaucoma and EXS samples in comparison to cataract controls (P < 0.05).


CONCLUSIONS
TIMP-2 is elevated in glaucomatous process over MMP-2, which support and further extend the conjuncture that the ECM accumulation rather than degradation predominates in the pathogenesis of POAG and EXG.
Määttä
Marko
M
Clinic of Ophthalmology, University Central Hospital of Helsinki, Finland. mmaatta@mailcity.com
Tervahartiala
Taina
T
Harju
Mika
M
Airaksinen
Juhani
J
Autio-Harmainen
Helena
H
Sorsa
Timo
T
D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000201:enzymology*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D017889:Exfoliation Syndrome / Q000201:enzymology*; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005902:Glaucoma, Open-Angle / Q000201:enzymology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism*
D019714:Tissue Inhibitor of Metalloproteinases; D020782:Matrix Metalloproteinases