The Fibrinolysis Inhibitor α₂-Antiplasmin in the Human Cornea

Abstract

Purpose: To determine whether the cornea contains and expresses, at the gene level, the major plasmin inhibitor α₂-antiplasmin. Methods: Corneal sections were immunostained for α₂-antiplasmin. Extracts of human corneal stroma, epithelium, and endothelium were subjected to immunodot blot and Western blot analysis. Total RNA and α₂-antiplasmin specific primers were used for RT-PCR. The cDNA was sequenced. Results: α₂-Antiplasmin was observed in all three corneal layers by immunolocalization and Western blots. The major α₂-antiplasmin form observed in most extracts was the 70-kDa form. Total α₂-antiplasmin was present at 0.119 ± 0.014 μ g/epithelium (n = 10) and 1.45 ± 0.47 μ g/stroma (n = 10). α₂-Antiplasmin mRNA was detected in epithelial and stromal extracts and cultured human corneal stromal cells. The sequences of the PCR products were identical to that for human α₂-antiplasmin. Conclusions: α₂-Antiplasmin and its mRNA are present in the cornea and may serve to regulate corneal plasmin activity.

KEYWORDS:

• α₂-antiplasmin
• cornea
• fibrinolysis
• plasmin
• serpin