ARVO 2017 Day 3 Highlights
May 10, 2017
by Jennifer Phillips, Ph.D.
Lots of great presentations and productive meetings with friends and collaborators today, and my mind is kind of reeling from it all. There was a great session on Photoreceptor Cell Biology, Disease and Rescue that had a few tidbits our readers might find interesting.
That session title might sound like three distinct topics, but they’re actually quite interconnected. The common thread for many of the presentations was that understanding photoreceptor cell biology, specifically determining what’s normal and what leads to the symptoms of retinitis pigmentosa: gradual loss of photoreceptor function culminating in the death of those light-sensing cells. This type of research has significant potential—some of which is already being realized—to broaden the scope of how we investigate ways to rescue or prevent RP symptoms.
Several of the talks delved into the biology of what, specifically, causes photoreceptor cells to die in RP patients. It might surprise some of you to know that we actually can’t answer that question for most types of RP. There are some really good hypotheses, lots of general ideas, but there’s a lot we don’t know about the process.
More great work from the Usher research team at Radboud University Medical Center has revealed defects in how retinal cells with mutations in USH2A handle the ‘waste stream’, the process of moving molecules to the proper places for degradation or recycling. A new molecular partner in this process was identified, thus giving us a new target to learn about and to investigate for possible interventions.
Another interesting set of results was reported by Dr. Jingyu Yao, of the University of Michigan’s Kellogg Eye Center. Her team has investigated protein degradation mechanisms by analyzing different steps of the process in the photoreceptors of as many RP mouse models as they could get their hands on. This approach revealed some important similarities and differences in the specifics of how the waste management process is impaired in animals that, although suffering from diseases with similar symptoms at the tissue level, show a fair amount of variation at the molecular level.
An important point here is that cell death in most types of RP takes years to develop. There’s time to study the events that precede cell death, and it’s vital to know when to treat as well as what process the intervention should target. Another key to this field is the ability to categorize the many forms of RP using as many molecular parameters as possible. A treatment based on improving waste handling, for example, might be effective for some forms of RP but not others. This knowledge would be an important prerequisite to gearing experiments to maximize the number of people who could be helped as well as recruiting the right patients for clinical trials, among other considerations.
Tomorrow is PACKED with presentations, including my own. Stay tuned.