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The same process that causes dew drops to form on a blade of grass appears to play a role in brain diseases like Alzheimer's. NPR's Jon Hamilton reports on the scientist who made this discovery and how it may someday lead to new drugs for a wide range of illnesses.
JON HAMILTON, BYLINE: When Dr. J. Paul Taylor began practicing medicine, he saw himself as a sort of medical detective.
J PAUL TAYLOR: Typically, the most oddball diseases that didn't fit into another category would wind up in my clinic, which I loved.
HAMILTON: Today, Taylor is a researcher at St. Jude Children's Research Hospital and the Howard Hughes Medical Institute. But back then, he specialized in brain diseases that run in families. And one disease in particular got his attention.
TAYLOR: We had been tracking a number of families that had an unusual degenerative illness. It was kind of a blend of dementia and ALS.
HAMILTON: Patients develop the mental problems of dementia, as well as the muscle weakness of ALS, or Lou Gehrig's disease. Taylor figured there must be a genetic explanation. But at the time, he had no easy way to study his patients' DNA.
TAYLOR: So I collected those DNAs and hung on to them for years. And then the world changed around me.
HAMILTON: Suddenly, it became feasible to sequence a person's entire genome.
TAYLOR: I dug those DNAs back out of the freezer, and we were fortunate enough to find the genetic basis for the disease in these families that I had known for, at that point, a decade.
HAMILTON: Taylor found gene mutations that changed the inner workings of brain cells. They affected a process called phase transition. Taylor says it's something we see all around us.
TAYLOR: For example, the condensation of water on the petal of a flower that we call dew.
HAMILTON: Water vapor condenses into liquid water. It makes a transition from one phase to another. And inside cells, something similar is going on all the time. Phase transitions allow cells to quickly assemble and disassemble some of their internal machinery. But Taylor says the mutations were gumming up this process.
TAYLOR: It's as if you took a jar of honey, which has its normal viscosity - but if you were to leave it in the refrigerator overnight, there is a hardening.
HAMILTON: When that happens inside a cell, it stops functioning properly, and toxic substances begin to accumulate, including the toxic proteins associated with ALS and Alzheimer's. The discovery earned Taylor the 2020 Potamkin Prize, a big deal in Alzheimer's research. And he says it got a lot of biotech companies thinking about ways to fix problems with phase transitions inside cells.
TAYLOR: I think it's probably safe to say that you will see some of these types of therapies definitely within the next couple years.
HAMILTON: Or maybe a bit longer, says Cliff Brangwynne, a professor at Princeton and the Howard Hughes Medical Institute. Brangwynne published the first paper describing phase transitions in cells in 2009, and he says it should be possible to fix problems with this process. Inside a healthy brain cell, he says, many molecules act a bit like people socializing.
CLIFF BRANGWYNNE: Something like at a party where we've got little clusters of people hanging out and having nice conversations. They're free to come and go as they please, though. And in fact, even as they're talking, they're moving around and shifting a little bit.
HAMILTON: That can change, though, when a disease messes up phase transition.
BRANGWYNNE: What happens in neurodegenerative disease is that the people are irreversibly stuck together. They can't leave. This is the "Hotel California" of biomolecular interactions.
HAMILTON: But Brangwynne says it doesn't have to be. In the lab, at least, experimental drugs can unstick these molecules. And he says drugs like these could have applications far beyond the brain.
BRANGWYNNE: It's very clear that this principle is at play in many, many diseases.
HAMILTON: Including cancer and heart disease.
Jon Hamilton, NPR News.
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