Rutgers neuroscientist Peng Jiang was visiting his hometown of Qianshan in China’s Anhui province when a conversation with a neighbour left a deep and lasting impression. The man had come to Jiang’s parents’ home to share a painful story about his mother, one that captured the quiet devastation of Alzheimer’s disease in a way that statistics never could. As he spoke, it became clear that this was not simply a recollection of illness, but an expression of fear, grief, and uncertainty about the future.
The neighbour explained that his mother had been diagnosed with Alzheimer’s disease in her early sixties. Over nearly a decade, her condition slowly worsened, erasing memories and relationships until she no longer recognised her own son. One morning, she looked at him kindly and asked how his mother was doing, as if speaking to a stranger. Recounting the moment, the neighbour broke down. Alzheimer’s, he said, ran in his family, and he lived with the fear that his own children might one day watch him disappear just as he had watched his mother’s memory fade. The encounter stayed with Jiang long after he returned to the United States.
At the time, Jiang was already deeply involved in Alzheimer’s research, but the conversation sharpened his sense of purpose. Back at Rutgers University, where he is an associate professor in the Department of Cell Biology and Neuroscience and a faculty member of the Rutgers Brain Health Institute, Jiang returned to his laboratory with renewed urgency. The lack of effective treatments, he has said, only strengthened his resolve to explore new therapeutic ideas that might one day make a meaningful difference for families like the one he met in Qianshan.
That resolve has now contributed to a significant scientific advance. Working with his colleague Mengmeng Jin, the first author of the study, Jiang helped uncover a rare gene mutation that appears to protect the brain’s immune cells from the damage typically caused by Alzheimer’s disease. Their findings, published in Nature Neuroscience, suggest a shift in how researchers might think about treatment. Instead of focusing solely on genetic changes that increase disease risk, the team looked for mutations that promote resilience.
The work reflects a broader change in Alzheimer’s research. For many years, efforts have centred on removing toxic proteins that accumulate in the brain. While this approach has been informative, it has yet to deliver transformative therapies. Jiang’s research points towards another possibility: strengthening the brain’s own defence systems so they can remain effective for longer, even in the presence of disease-related pathology.
This idea emerged in part from observations in people with Down syndrome, who almost universally develop early-onset Alzheimer’s disease due to accelerated protein accumulation. Intriguingly, a small number never develop dementia. Investigating this resilience, the Rutgers team identified a rare mutation, CSF2RB A455D, in the immune cells of some individuals with Down syndrome. Using stem cell technology, they created human microglia carrying the mutation and studied how these cells behaved in living brain environments exposed to Alzheimer ’s-related proteins.
The mutated microglia remained healthy, avoided chronic inflammation, and were more effective at clearing harmful proteins and protecting neurons. Over time, they even outperformed unmutated cells. The discovery opens the door to potential therapies that enhance the brain’s natural defences, offering a new source of hope rooted in both human experience and biological insight.
More information: Mengmeng Jin et al, A myeloid trisomy 21-associated gene variant is protective from Alzheimer’s disease, Nature Neuroscience. DOI: 10.1038/s41593-025-02117-8
Journal information: Nature Neuroscience Provided by Rutgers University
