Overview: A newly developed blood-based test reveals changes in hippocampal neurogenesis up to 3.5 years before the clinical diagnosis of Alzheimer’s disease.
Source: King’s College London
New research from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London has developed a blood-based test that can be used to predict Alzheimer’s risk up to 3.5 years before clinical diagnosis.
The study, published in the journal Brain, supports the idea that components in human blood can modulate the formation of new brain cells, a process called neurogenesis. Neurogenesis takes place in an important part of the brain called the hippocampus, which is involved in learning and memory.
Although Alzheimer’s disease affects the formation of new brain cells in the hippocampus during the early stages of the disease, previous studies have only been able to study neurogenesis in the later stages through autopsies.
To understand the early changes, researchers collected blood samples from 56 individuals over several years with mild cognitive impairment (MCI), a condition in which someone begins to experience a deterioration in their memory or cognitive ability.
While not everyone who experiences MCI develops Alzheimer’s disease, those with the condition develop a diagnosis much more quickly than the rest of the population. Of the 56 study participants, 36 were diagnosed with Alzheimer’s disease.
Dr. Aleksandra Maruszak, one of the joint first authors of King’s IoPPN, explains: “In our study, we treated brain cells with blood from people with MCI, examining how those cells changed in response to blood as Alzheimer’s disease progressed.”
In studying how blood affected brain cells, the researchers made several important discoveries. The blood samples collected over the years from participants who subsequently deteriorated and developed Alzheimer’s disease promoted a decrease in cell growth and division and an increase in apoptotic cell death (the process by which cells are programmed to die).
However, the researchers noted that these samples also increased the conversion of immature brain cells into hippocampal neurons.
While the underlying reasons for the increased neurogenesis remain unclear, the researchers theorize it may be an early compensatory mechanism for the neurodegeneration (loss of brain cells) experienced by those who develop Alzheimer’s disease.
Professor Sandrine Thuret, the lead author of the study from King’s IoPPN said: “Previous studies have shown that blood from young mice can have a rejuvenating effect on the cognition of older mice by enhancing hippocampal neurogenesis. This gave us the idea to model the process of neurogenesis in a dish using human brain cells and human blood.
“In our study, we wanted to use this model to understand the process of neurogenesis and to use changes in this process to predict Alzheimer’s disease. new cells.”
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When the researchers used only the blood samples furthest from when the participants were diagnosed with Alzheimer’s disease, they found that the changes in neurogenesis occurred 3.5 years prior to a clinical diagnosis.
Dr. Edina Silajdžić, the study’s joint first author, added: “Our findings are extremely important, allowing us to predict early onset of Alzheimer’s disease in a non-invasive way. This could complement other blood-based biomarkers that reflect the classic signs of the disease, such as the accumulation of amyloid and tau (the ‘flagship’ proteins of Alzheimer’s disease).”
Dr. Hyunah Lee, the study’s joint first author, said: “It is now essential to validate these findings in a larger and more diverse group of people. We’re excited about the potential applications of the blood-based test we’ve been using. For example, it could help stratify individuals with memory problems for a clinical trial of disease-modifying drugs for Alzheimer’s disease.”
The researchers say these findings may provide an opportunity to further understand the changes the brain goes through in the earliest stages of Alzheimer’s disease.
About this news about Alzheimer’s disease
Writer: Press Office
Source: King’s College London
Contact: Press Service – King’s College London
Image: The image is in the public domain
Original research: The findings appear in Brain