A team of Wayne State University researchers recently received a $1.9 million grant from the National Eye Institute of the National Institutes of Health to better understand leukodystrophies (LD) and genetic Leukoencephalopathies (gLE), rare genetic disorders affecting the white matter -- myelin -- in the central nervous system. Patients diagnosed with a leukodystrophy experience a gradual decline in development, including a progressive loss in gait, body tone, vision, hearing, swallowing and/or ability to eat.
LD and gLE disrupt the growth or maintenance of the myelin sheath, which insulates nerve cells. LD and gLE affect motor and sensory systems, including visual systems, causing vision to slowly worsen until vision is lost. Most leukodystrophies are genetic, but many of the genes that cause the disease are currently unknown.
The Wayne State team, led by Ryan Thummel, Ph.D., assistant professor of anatomy and cell biology and ophthalmology in Wayne State's School of Medicine, recently discovered that a mutation in Vacuolar Protein Sorting 11 (VPS11) is a cause of a type of leukoenephalopathy. The team, which includes Thummel; Robert Skoff, Ph.D., professor of anatomy and cell biology at Wayne State; James Granneman, Ph.D., professor of psychiatry at Wayne State; and Brian Perkins, Ph.D., associate professor at the Lerner Research Institute at the Cleveland Clinic, will use a previously characterized zebrafish mutant line of VPS11 to better understand the progression and model for this disease, with a special focus on progressive vision loss.
"Zebrafish are a highly suited model for this disease and can be used to test behavioral and biological aspects of the disease," said Thummel. "In addition, given their small size and large number of offspring, they are highly amenable to use in a screen for compounds that rescue the disease. Finally, with the expertise of Dr. Skoff, we will develop a mammalian brain cell culture technique to analyze how defects in VPS11 effect myelin formation and support of adjacent neurons."
According to Thummel, one in 8,000 individuals suffers from vision loss associated with LD and gLE. The results from their research study are expected to provide insight into how disrupted protein trafficking can lead to white matter diseases and provide potential therapeutic targets.
In addition to his work with LD and gLE, Thummel is working with a collaborative team on a project known as the "Kids Without Cancer Zebrafish Initiative," funded by Kids Without Cancer through a gift to Children's Hospital of Michigan Foundation. This initiative is investigating the impact of potential toxins such as pesticides on the development of leukemia, which will lay the foundation for large-scale screening for other causative agents. The first pesticide being tested is propoxur, a commonly used insecticide used to control lawn and turf insects, household pests, and fleas.