Did you know that only about 2% of your DNA contains actual genes? The other 98%—often called “junk” DNA—was long thought to do nothing important.
But scientists now know that much of this DNA contains special sections called enhancers. These are like switches that turn genes on and off, and they may play a key role in how our cells work.
Now, researchers at UNSW Sydney have discovered a group of these switches that help control how brain cells called astrocytes work. Astrocytes are support cells in the brain that help neurons and are linked to diseases like Alzheimer’s. The research was published in the journal Nature Neuroscience.
The team studied nearly 1,000 of these DNA switches, or enhancers, in human astrocytes grown in a lab.
They used a powerful tool called CRISPRi, which can turn off tiny pieces of DNA without cutting them, and combined it with single-cell RNA sequencing, a method that measures gene activity in each cell. This helped them figure out which switches actually control important genes.
Dr. Nicole Green, the lead author, explained that when they turned off some of these enhancers, they saw changes in how genes behaved. That’s how they knew they had found real, working gene switches. Out of the 1,000 tested, about 150 turned out to be functional. Many of these were found to control genes involved in Alzheimer’s disease.
This is a big step forward. Out of the huge non-coding area of DNA, these 150 enhancers give scientists a much smaller and more focused set of places to look when trying to understand the genetics behind Alzheimer’s.
Professor Irina Voineagu, who led the project, says the findings are helpful not just for Alzheimer’s but also for other diseases.
When scientists search for the genetic causes of diseases like diabetes, heart disease, or mental health disorders, the changes they find in DNA are often in those “in-between” parts, not directly inside genes. The new list of real enhancers in brain cells can help explain what those DNA changes actually do.
This work is also important because it’s the first large-scale test of this kind done directly in brain cells. It was hard work, but now that it’s done, the data can help train computer programs to predict which other enhancers might be real. For example, the tech team at Google DeepMind is already using this dataset to test their AI model called AlphaGenome.
Another exciting possibility is using this research in future treatments. Since different enhancers work in different cell types, it may one day be possible to control genes only in certain brain cells, like astrocytes, without affecting others.
This could lead to more precise therapies. There is already a gene-editing drug for sickle cell anemia that targets a specific enhancer in blood cells.
Dr. Green says this line of research could be key to developing precision medicine—treatments that are tailored to specific cells or people. The idea is to figure out which enhancers can safely and effectively turn genes on or off, only where they are needed.
While these discoveries won’t lead to immediate treatments, they do bring us one step closer to understanding how brain diseases work—and how we might one day fix them.
If you care about Alzheimer’s disease, please read studies about root cause of Alzheimer’s disease and new treatment and Scientists find the link between eye disease glaucoma and Alzheimer’s disease.
For more health information, please read studies about new way to treat Alzheimer’s disease and Fluctuating cholesterol and triglyceride levels are linked to Alzheimer’s disease.
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