Analysis of the ribozyme mediated cleavage of the RNA associated with retinal disease

RNA sequences called ribozymes have been discovered that are able to cut other RNA molecules. The ability to design ribozymes able to cleave a specific RNA molecule led to the idea that they could be used as a gene therapy. The idea is that ribozymes can be used to degrade the mRNA of genes responsible for disease. The hypothesis behind this research is that ribozymes can be used to inhibit the expression of disease causing genes leading to a delay or prevention of the disease. Autosomal dominant diseases may be particularly amenable to treatment by ribozymes as the expression of a single mutant gene results in disease. Genetic forms of blindness are easier to treat than other types of genetic diseases since the eye is easily accessible, and is an immune privileged site. This facilitates the delivery and expression of genes in the eye. The goal of this project was to design ribozymes for the treatment of two different retinal diseases. Both of these retinal diseases are caused by mutations in the rod opsin gene.; The success of this project depended on the completion of three specific aims. The first aim was to design ribozymes able to specifically degrade RNA sequences corresponding to the mutant rhodopsin sequences responsible for disease. The second aim was to characterize these ribozymes in vitro . The purpose of the second aim was to identify those ribozymes that had the greatest chance for success as a gene therapy. The third aim of this project was to create a viral vector capable of expressing the selected ribozymes in the eye. A number of ribozymes have been designed and shown to cleave mutant RNA sequences responsible for blindness in a test tube. These ribozymes are currently being examined for their therapeutic effectiveness in animal models.