The Lauderdale Lab

Developing a cell-based approach for the treatment of aniridia related keratopathy

The Lauderdale lab is investigating the role that the PAX6 gene plays in maintaining the cornea and how it can be used to treat aniridia related keratopathy (ARK). The PAX6 gene is needed for both the formation and maintenance of the cornea, particularly the corneal epithelium. The corneal epithelium can be though of as a specialized form of skin. Like our skin, cells in the corneal epithelium constantly being lost and replaced as part of its normal function. A specialized group of cells, called limbal stem cells, are responsible for generating the new cells that are used to replace the cells in the corneal epithelial layer. These cells are located in the region of the eye where the clear part of the cornea meets the white part of the eye. Loss or damage to these limbal stem cells results in problems in the bodys ability to maintain the corneal epithelial layers, and is the cause of the corneal diseases known as keratopathies.

We are developing a cell based method for the treatment of aniridia related keratopathy using a person’s own cells. The goal is to develop a method that is well tolerated in children and can be used to maintain vision during the person’s lifetime. Aniridia related keratopathy results from a decrease in the amount of PAX6 protein in the limbal stem cells and the cells that are produced by these cells. Our approach is to take a small sample of limbal cells from the individual with aniridia and then in the laboratory add back a functional copy of the PAX6 gene (represented by the green cells in the figure). These cells would then be grown on a substrate, such as a contact lens, that would allow the cells to be reintroduced into the patients eyes.

Previous funding from the Childrens Glaucoma Foundation facilitated the developmental phase of this project, which took advantage of our mouse model of aniridia and a rabbit surgical model of limbal stem cell deficiency. Rabbits are good models for developing techniques that can be used for treatment of human eye diseases because of the size of their eyes. Our current funding from the Childrens Glaucoma Foundation is being used to translate this approach into one that can be used in the clinic. Specifically we are investigating the use of a contact-lens based delivery system that could be used to reintroduce the modified limbal progenitor cells to a persons eyes.