Identification of Uniquely Expressed Trabecular Meshwork Genes

By the year 2000, the number of people with primary glaucoma in the world will reach nearly 66.8 million. Classically, glaucoma has been thought to be a disorder of increased intraocular pressure, which, when sufficiently elevated produces characteristic damage of the optic nerve. The molecular cause of primary open angle glaucoma has yet to be determined. However, it is generally accepted that elevated intraocular pressure results from increased resistance inside the eye to normal aqueous humor outflow. The location of at least 75% of this resistance is in a tissue called the trabecular meshwork. While many of the proteins that make up this tissue have been characterized, the critical pieces are still unknown. Identification of the protein(s) that may cause the fatal flaw in glaucoma is of paramount interest, since new therapies and treatments can then be designed based upon this knowledge. This proposal will use a new molecular technique called “differential display of mRNA” to identify new trabecular meshwork genes. These genes may potentially play a critical role in regulation of outflow and thus, control of intraocular pressure. Our major hypothesis is that the trabecular meshwork cells regulate aqueous outflow, and consequently intraocular pressure, by replacing and updating the extracellular matrix as needed. Identification and characterization of genes that are specifically expressed by the trabecular meshwork will give us further insight into how the trabecular meshwork regulates outflow.

Specific Aim 1. Identify uniquely expressed trabecular meshwork genes or those produced in high abundance in comparison to adjacent eye tissue.

Specific Aim 2. Characterize the trabecular meshwork cDNAs identified above.

Specific Aim 3. Using immunohistochemical techniques, determine the physical location in the anterior segment of the trabecular meshwork proteins identified in Specific Aim 1.

Our long term goals are to characterize each trabecular meshwork gene identified by these methods and use this knowledge to begin to delineate how the trabecular meshwork regulates outflow. With a clearer understanding of the regulation of this filtration apparatus, therapies can be designed that will be better suited for treatment or prevention of glaucoma.