What if the brain already has a cleanup crew for Alzheimer’s disease, but that crew needs a stronger signal to get moving? Researchers have found that raising levels of a protein called Sox9 helped star-shaped brain cells clear damaging plaques in mice that already had memory problems.
The finding does not mean a human treatment is ready. It does suggest a different way to think about Alzheimer’s, one that looks beyond neurons and asks whether the brain’s support cells can be turned into a stronger line of defense.
A different Alzheimer’s target
Alzheimer’s disease is the most common form of dementia, the broad term for brain disorders that harm memory, thinking, and daily life. The World Health Organization reported that 57 million people had dementia worldwide in 2021, and Alzheimer’s disease may account for most of those cases.
For families, those numbers are not abstract. They can mean repeated questions at breakfast, missed names, lost keys, and eventually the hard work of helping someone through ordinary routines.
Most Alzheimer’s research has focused on neurons, the cells that send messages and help store memories. Many efforts also target amyloid plaques, sticky clumps of protein that build up in many affected brains.
The new work asks a practical question about what happens if scientists help the brain remove plaques that are already there.
The brain’s overlooked helpers
The study focuses on astrocytes, which are brain cells named for their star-like shape. They are not the famous message-carrying neurons, but they help keep the brain’s environment stable, support communication between cells, and play a role in memory.
Dr. Dong-Joo Choi, the study’s first author, has emphasized that astrocytes support communication and memory storage. He also noted that these cells change deeply as the brain ages, but scientists still do not fully understand what those changes mean for Alzheimer’s disease.
That matters because support cells are easy to underestimate. They may not be the lead actors in the brain’s daily drama, but they keep the stage from collapsing. In this study, researchers at Baylor College of Medicine tried to see whether those cells could do more than support.
How Sox9 changed the cleanup
The team focused on Sox9, a protein that helps control which genes are active inside aging astrocytes. Think of it as a switchboard operator, not a broom. By changing the signals inside the cell, it can affect how the cell behaves.
When the researchers increased Sox9 in mouse models of Alzheimer’s disease, astrocytes became more active and removed more amyloid plaques. Dr. Benjamin Deneen, the study’s senior author, said boosting Sox9 made astrocytes clear plaques “like a vacuum cleaner.”
The process depended on another molecule called MEGF10. In simple terms, MEGF10 works like a grab handle that helps astrocytes swallow and break down unwanted material. The study found that the Sox9 and MEGF10 pathway helped clear plaques and preserve cognitive function in Alzheimer’s mouse models.
Why the mouse model matters
Here is the important twist. The researchers did not act before the disease-like changes appeared. They used mice that already had amyloid plaques and memory deficits, which makes the experiment closer to the situation doctors often see in patients.
That timing makes the result more interesting, for the most part, because many people are diagnosed after symptoms begin. In the experiment, the mice were followed for six months while the team tested memory-related behaviors and checked plaque buildup in the brain.
The contrast was sharp. Increasing Sox9 was linked to more plaque removal and better preserved cognitive function, while reducing Sox9 made plaque buildup worse and astrocytes less complex. It is not a cure, but it is a clear signal that these support cells may shape the course of disease.
A wider shift in brain research
This finding fits a broader change in Alzheimer’s science. A 2020 study identified disease-associated astrocytes in mouse models and aging human brains, suggesting these cells are tied to both disease progression and aging.
Other recent work has also placed astrocytes closer to the center of the Alzheimer’s puzzle. Research discussed by the UK Dementia Research Institute in 2024 found that astrocytes can influence amyloid buildup linked to the APOE gene, one of the best-known genetic risk factors for Alzheimer’s.
So, are astrocytes friends or troublemakers? The honest answer is probably both, depending on the moment, the brain region, and the signals they receive. That is exactly why scientists are paying closer attention.
What comes next
There is a major caution here. The study was done in mice, and mouse brains are not human brains. Experts will need to learn whether safely boosting Sox9, or the pathway it controls, can help people without creating new risks.
The work was supported in part by the National Institutes of Health, with additional backing from research resources connected to Houston Methodist and the David and Eula Wintermann Foundation. That kind of support matters because turning a mouse result into a therapy is a long road, full of false starts.
Still, the idea is hard to ignore. Instead of only blocking damage from the outside, future Alzheimer’s strategies may try to strengthen the brain’s own housekeeping system from within. Small signal, big question.
The main study has been published in Nature Neuroscience.
