Although a treatment capable of curing Alzheimer’s disease has not yet been found, its early detection would allow for interventions that help delay Alzheimer’s symptoms, such as cognitive deficits and memory loss, and improve the quality of life of patients. and their families. Scientists at King’s College London’s Institute of Psychiatry, Psychology and Neuroscience (IoPPN) have now designed a new blood test that could be used to predict the risk of developing Alzheimer’s up to 3.5 years before clinical diagnosis.
The results of the study support the hypothesis that the elements that make up human blood can influence the formation of new brain cells, a process known as neurogenesis that occurs in the hippocampus – a key area of the brain involved in learning. and memory – and who is affected by Alzheimer’s in the early stages of the disease.
Understanding the neurogenesis process to predict Alzheimer’s
Over several years, the researchers collected blood samples from 56 patients with mild cognitive impairment (MCI), a disorder characterized by memory disturbances that can increase the chances of developing dementia. Of these 56 individuals, 36 received an Alzheimer’s diagnosis. “In our study, we treated brain cells with blood taken from people with DCLI, looking at how those cells changed in response to blood as Alzheimer’s disease progressed,” explained Aleksandra Maruszak, MD, one of the authors of the study. research.
“Our findings are extremely important, as they potentially allow us to predict the early onset of Alzheimer’s disease in a non-invasive way.”
The researchers found that blood samples drawn from participants over the course of the study who subsequently deteriorated and developed Alzheimer’s disease promoted a reduction in cell growth and division and an increase in apoptotic cell death (the process by which cells are programmed to die). However, they found that these samples also increased the conversion of immature brain cells into hippocampal neurons.
Although they have not been able to clarify why the increase in neurogenesis occurs, the scientists hypothesize that it may be an early compensatory mechanism for the neurodegeneration (loss of brain cells) experienced by people who develop Alzheimer’s disease.
Previous studies have shown that blood from young mice can have a rejuvenating effect on the cognitive ability of elderly mice by enhancing hippocampal neurogenesis, says Professor Sandrine Thuret, lead author of the study, adding that this gave them the idea to mimic the process of neurogenesis in a dish using human brain cells and human blood, with the goal of “using this model to understand the process of neurogenesis and using changes in this process to predict Alzheimer’s disease.” The expert says that, in this way, they found “the first evidence in humans that the body’s circulatory system can have an effect on the brain’s ability to form new cells.”
When the researchers used only blood samples drawn from the participants further away from the time they were diagnosed with Alzheimer’s, they found that changes in neurogenesis occurred 3.5 years before clinical diagnosis. The results of the study have been published in the journal Brain and, according to the authors, may constitute an opportunity to better understand the changes that occur in the brain during the early stages of Alzheimer’s disease.
Dr. Edina Silajdžić, co-first author of the study, concludes: “Our findings are extremely important, as they potentially allow us to predict the early onset of Alzheimer’s disease in a non-invasive way. This could complement other blood biomarkers that reflect classic signs of the disease, such as the accumulation of amyloid and tau (the ‘flagship’ proteins of Alzheimer’s disease).”
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