UMass Boston professor looks for clues to preserving human vision
Assistant Professor of Biology Jens Rister has made a career of studying eyes. As a PhD student at the University of Würzburg in Germany he studied how flies see motion and why it’s difficult to swat a fly; as a post-doc at New York University he learned how to understand the development of the eye and the genes expressed in the eye. Now he’s fusing that work together.
Last month, the third-year faculty member received the 2018 Endowed Faculty Career Development Award at the annual UMass Boston Retired Faculty Luncheon. The $3,500 award, which comes from yearly gifts given by retired UMass Boston faculty members, will support Rister’s work to understand how the eye responds to a lack of Vitamin A and to identify potentially protective mechanisms to prevent blindness.
“If you have a chronic lack of Vitamin A in your diet, you don’t eat your carrots or drink milk or eat liver or squash, then you will have permanent eye damage. You will become blind because the light-sensing cells in your eye, photoreceptors, will actually die from lack of Vitamin A,” Rister said.
Rister said flies have a very similar problem. Their photoreceptors also get severely damaged from lack of Vitamin A, but they don’t die.
“What we don’t know yet really is what’s going on in the photoreceptor when it’s stressed in that particular way. We don’t know if there are any molecules that sense the damage. Are there molecules that know that there’s not enough Vitamin A? And are there any molecules that stabilize the damaged cell?” Rister said. “The fact that in flies the cells don’t die indicated to us that there’s some kind of molecule or pathway that might stabilize the dying cell and keep some its function still alive.”
Rister says the sensory neurons in your nose and your tongue are regenerated. But once the photoreceptors die, from lack of Vitamin A or looking into the sun too long, they can’t come back. According to the World Health Organization, Vitamin A deprivation is the leading cause of preventable blindness in children.
“If we can find something in the flies that stabilizes photoreceptors that are in trouble, that could lead to new therapeutical approaches that would be useful to humans for sure,” Rister said.
Rister explained that fruit flies, Drosophila melanogaster, make the perfect subject for studying the effects of Vitamin A deficiency on the eye.
“Flies don’t need Vitamin A to develop normally. If [humans] grow up without Vitamin A, [they] show growth defects and increased mortality risk because we need Vitamin A for the proper function of our immune system,” he said. “Flies appear to need it only for the eye, so we can specifically study the role in the eye and don’t have to worry about other health issues in the fly.”
To detect changes in gene expression in response to Vitamin A deprivation, Rister and the students in his lab use high throughput sequencing that is performed in the Center for Personalized Cancer Therapy’s Genomics Core. Meanwhile, Andrej Shevchenko, a close collaborator at the Max Planck Institute, Dresden, uses mass spectrometry to identify proteins that change in response to Vitamin A deprivation.
Rister says this collaborative research is a pathway for addressing eye diseases in humans.
“Vitamin A deprivation is just an easy access method to stress the eye, much, much easier than anything else,” he said. “You either add or omit Vitamin A when preparing the fly food. It’s a shortcut to getting to these protective pathways, and we believe this is a very innovative approach.”
The vial in the red, shown at the right in the photo below, contains food with Vitamin A. Down the road, Rister would like to understand other dietary impacts on eyes, such as high-fat, low-fat, and even fast food diets. So yes, this includes studying how McDonald’s impacts Drosophila melanogaster.