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Abstract #5592 Published in IGR 2-1
Plasminogen activator inhibitor-1 mRNA is localized in the ciliary epithelium of the rodent eye
Masos T; Dan JA; Miskin RInvestigative Ophthalmology and Visual Science 2000; 41: 1006-1011
PURPOSE: To identify in the adult and developing rodent eye cells expressing the gene encoding plasminogen activator inhibitor-1 (PAI-1), an important component of the fibrinolytic system. METHODS: PAI-1 mRNA was localized in cryostat thin eye sections via in situ hybridization analysis using specific 35S-labelled riboprobes. PAI-1 activity was tested in the aqueous humor using one-phase reverse zymography. RESULTS: In the adult eye, PAI-1 mRNA was detected exclusively in epithelial cells of the ciliary processes, primarily in the apexes. In addition, PAI-1 activity was detected in the aqueous humor. PAI-1 mRNA was first found in the ciliary epithelium in embryonic day 18.5, when the ciliary body has reached an advanced developmental stage. PAI-1 mRNA was also detected in the ganglion cell layer of the retina on postnatal days 1-4, when angiogenesis takes place. CONCLUSIONS: During development, PAI-1 is likely to be involved in retinal vascularization, in agreement with other cases of angiogenesis. Results for the adult eye indicate that the ciliary epithelium is the source of PAI-1 activity found in the aqueous humor. The results suggest that PAI-1 plays a role in balancing fibrinolysis and proteolysis specifically in the anterior segment of the eye, implying that PAI-1 overproduction in the ciliary epithelium could shift the balance against proteolysis and thus may interfere with aqueous outflow.
Dr. R. Miskin, Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel. ruth.miskin%weizmann.ac.il
Classification:
2.9 Ciliary body (Part of: 2 Anatomical structures in glaucoma)
