Extracellular matrix and Na+,K+-ATPase in human corneas following cataract surgery: comparison with bullous keratopathy and Fuchs' dystrophy corneas.
OBJECTIVE
To examine the distribution of extracellular matrix (ECM) and basement membrane (BM) components and of Na+,K+-ATPase in postcataract surgery (PCS) corneas. These corneas were from patients who never developed pseudophakic or aphakic bullous keratopathy (PBK/ABK) after cataract surgery. PCS corneas were compared with PBK/ABK and Fuchs' dystrophy corneas.


METHODS
The distribution of PBKIABK ECM and BM markers and of all three Na+,K+-ATPase alpha subunits was studied by immunofluorescence in 10 healthy, 11 PCS, 16 PBK/ABK, and 12 Fuchs' dystrophy corneas.


RESULTS
Fibrotic ECM proteins, tenascin-C and fibrillin-1, were found in only 1 of 10 healthy and in 2 of 11 PCS corneas. In contrast, these proteins were expressed in all PBK/ABK and more than half of the Fuchs' dystrophy corneas. BM components in PCS corneas were altered to a greater extent (40-60%), especially fibronectin and laminin-10. A decreased epithelial immunostaining for Na+,K+-ATPase alpha subunits was seen in approximately 40% of PCS corneas and in approximately two thirds of PBK/ABK and Fuchs' dystrophy corneas. However, the endothelial staining was normal in all groups.


CONCLUSIONS
Because tenascin-C and fibrillin-1 were mostly found in diseased but not in PCS corneas, their expression may be related to later, clinical stages of corneal edema development. However, BM components abnormal in PBK/ABK and Fuchs' dystrophy corneas were also altered in PCS corneas without clinical evidence of ocular disease. This may result from subclinical corneal changes resulting from cataract surgery, lens removal, exposure to the intraocular lens, or endothelial cell damage. Alterations of epithelial Na+,K+-ATPase point to the importance of epithelial changes in the development of corneal edematous diseases.
Ljubimov
Alexander V
AV
Ophthalmology Research Laboratories, Burns and Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA. ljubimov@cshs.org
Atilano
Shari R
SR
Garner
Margaret H
MH
Maguen
Ezra
E
Nesburn
Anthony B
AB
Kenney
M Cristina
MC
D001485:Basement Membrane / Q000378:metabolism; D015153:Blotting, Western; D015715:Corneal Edema / Q000209:etiology / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000473:pathology; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005642:Fuchs' Endothelial Dystrophy / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D016326:Extracellular Matrix Proteins; D000254:Sodium-Potassium-Exchanging ATPase