A new report in the journal Nature shows a significant step forward in figuring out what causes things to go wrong in the brain early on in Alzheimer’s disease.
The research could lead to new treatments.
More than 5 million Americans have Alzheimer’s disease, and that number is projected to triple by 2050. So there’s urgent demand for treatments — or even better, a cure — but so far, there has been little progress on that front.
Connecting the dots
Scientists have long known that carrying a bad variant of the gene APOE4 greatly increases the chance of developing the disease later in life.
Researchers looked at the postmortem brains of people who carried these bad APOE4 variants and they tried to “connect the dots” biologically between having APOE4 and actually getting Alzheimer’s.
They systematically analyzed thousands of genes and how they were expressed in the brain, meaning whether they were turned on or off, looking for patterns.
A promising lead
They were looking for a “smoking gun” — a traceable molecular path between APOE4 and developing the disease — and they did identify a handful of possible smoking guns.
One of the new findings in this research is that a gene called SV2A could be important in the development of Alzheimer’s.
It’s already known that it’s possible to block that gene using an anti-seizure drug, so that drug could help fight Alzheimer’s.
Words of caution
The lead researcher, Dr. Asa Abeliovich, a neuroscientist at Columbia University’s Taub Institute, cautions that though this is clearly a promising lead, it’s too early to think about treatment based on these findings.
“It’s really important to emphasize that this is still in an early, pre-clinical stage,” Abeliovich said. “It’s exciting that there are safe drugs out there that can hit this target, but I think it would be inappropriate at this point to start taking that medicine based on our work alone.”
ROBIN YOUNG, HOST:
It's HERE AND NOW.
A new report in the journal Nature shows a significant step forward in figuring out what causes things to go wrong in the brain early on in Alzheimer's. And these new findings could lead to new treatments. More than 5 million Americans have Alzheimer's. That number is projected to triple by 2050. There is an urgent need for treatment, even better, a cure. But so far, little progress. Carey Goldberg is health reporter at our home station, WBUR. And so, Carey, we know this research that's been done is on the more common form of Alzheimer's. It begins late in life. This is not early onset.
CAREY GOLDBERG, BYLINE: That's right, Robin. This research breaks new ground in figuring out what may first go wrong in the most common form of Alzheimer's, what's called the late-onset form that affects most people who get the disease. Until now, a lot of the work on the biology of Alzheimer's has focused on a rare form of the disease that runs in families and strikes relatively early. But this new research took a look at a gene that's a common risk factor for getting this late-onset Alzheimer's. It's a gene that's called APOE4. That's A-P-O-E-4.
And having the bad version of it can triple or even - actually, if you have two of them, multiplied by 10 your chances of getting Alzheimer's as you age. And it's very common. Nearly a third of us have that bad variant. So the researchers behind this paper were looking for sort of like the molecular chains of events that start with this bad gene, the APOE4 gene, and end with the disease. And they were hoping that they could find some points on that chain that could serve as early markers of the disease or be targeted for drugs.
YOUNG: So how did they do this?
GOLDBERG: So they kind of started from the end and worked backwards. But what happens in Alzheimer's is that your brain gets get kind of gummed up by these plaques and tangles of abnormal proteins that end up destroying brain tissue and leading to the dementia that we all know about and, eventually, death. It's not clear exactly why this happens. But we do know that this Alzheimer's gene, the APOE4 gene, is the biggest risk factor for late-onset Alzheimer's aside from aging itself.
So these researches looked at the brains after death - that is post-mortem - of people who carried these bad APOE4 variants, and they tried to kind of connect the dots biologically between having this APOE4 gene and actually getting Alzheimer's. They systematically analyzed thousands of genes and how they were expressed in the brain, meaning whether they were turned on or turned off, and they were looking for patterns. They were looking for kind of like a smoking gun, kind of a traceable molecular path between this APOE4 gene and developing the disease. And they did, in fact, identify a handful of possible smoking guns.
YOUNG: Whoa. So can they be targeted? I mean, does this mean that that's where therapy can come in?
GOLDBERG: Right. So that's the next question, obviously, is just knowing more about these connections, does that lead to possible new drugs that we could try? And the answer is yes, possibly. One of the new findings in this research is a gene that's called SV2A, could be important in development of Alzheimer's. And it's already known that it's possible to block this gene by using a drug for seizures, for epilepsy. So that immediately suggests that maybe this drug could be used to help fight Alzheimer's.
But the lead researcher on this new paper, Dr. Asa Abeliovich, who's a neuroscientist at Columbia University's Taub Institute, cautions that though this clearly is a promising lead, it's way too early to think about treatment based on these findings.
DR. ASA ABELIOVICH: It's exciting that there are safe drugs out there that can hit this target. But I think it would be inappropriate at this point to start taking that medicine based on our work alone.
GOLDBERG: So it's way too early now but it does raise this possibility. And it's great because Alzheimer's has been really frustrating over the last few years, and an advance like this is particularly welcome. And also this particular gene variant that's so widespread, it could actually now help us more to know if we have that variant because we may be able to take action beyond just making lifestyle changes. We may eventually be able to use a drug on it.
YOUNG: That's quite something. But, Carey Goldberg, health reporter at our home station WBUR, who's so careful, I asked you is this great news? It sounds like great news. And you said it's promising news.
GOLDBERG: It's a beginning, yes.
YOUNG: Carey, thanks so much.
GOLDBERG: You're welcome. Transcript provided by NPR, Copyright NPR.