Summary: 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 and Neuroscience (IoPPN) at King’s College London has established a blood-based blood test that can be used to predict Alzheimer’s risk up to 3.5 years before a clinical diagnosis.
The study was published in the journal Brain, supports the idea that substances in human blood can regulate the formation of new brain cells, a process called neurogenesis. Neurogenesis occurs in an important part of the brain called the hippocampus, which is involved in learning and memory.
Alzheimer’s disease affects the formation of new brain cells in the hippocampus at the beginning of the disease, previous studies have been able to study neurogenesis in the later stages of the disease.
To understand the early changes, researchers collected blood samples from 56 people with mild cognitive impairment (MCI) over several years.
Although not everyone who develops MCI will develop Alzheimer’s disease, people with the condition go on to be diagnosed at a faster rate than the general population. Of the 56 participants in the study, 36 received a diagnosis of Alzheimer’s disease.
Dr. Aleksandra Maruszak, from King’s IOPPN, one of the study’s first authors, said: “In our study, we treated brain cells with blood taken from people with MCI, and examined how the cells respond to blood as Alzheimer’s disease progresses.
By studying how blood affects brain cells, the researchers made several key discoveries. Blood samples collected from participants over the years showed that those who developed Alzheimer’s disease had decreased cell growth and division and increased apoptotic cell death (the process by which cells are programmed to die).
However, the researchers reported that these samples increased the conversion of immature brain cells into hippocampal neurons.
Although the underlying causes of neurogenic growth are unclear, researchers theorize that it may be an early compensatory mechanism for the neurodegeneration (loss of brain cells) experienced by people with Alzheimer’s disease.
Study leader Professor Sandrine Tourette from King’s IOPN said: “Previous research has shown that blood from young mice can improve hippocampal neurogenesis and have a rejuvenating effect on the cognition of older mice. This gave us the idea to model neurogenesis in a dish using human brain cells and human blood.
“In our study, we used this model to understand the neurogenesis process and use changes in this process to predict Alzheimer’s disease and we obtained the first data in humans that the circulatory system in the body affects the brain’s ability to generate new cells.”
When the researchers used only blood samples collected from the time the participants were diagnosed with Alzheimer’s disease, they found changes in neurogenesis up to 3.5 years before a clinical diagnosis.
Dr. Edina Silajcic, first author of the study, added, “Our findings are extremely important, allowing us to predict Alzheimer’s disease at an early stage in a non-invasive fashion.” This may complement other blood-based biomarkers that reflect early signs of the disease, such as the accumulation of amyloid and tau (Alzheimer’s disease ‘flagship’ proteins).
Dr. Hyunah Lee, first author of the study, said, “It is now important to confirm these findings in a larger and more diverse group of people. We are excited about the potential applications of our blood-based tests. For example, it helps conduct clinical trials of drugs to treat Alzheimer’s disease in people with memory problems.
The researchers said these findings provide an opportunity to better understand the changes the brain undergoes in the early stages of Alzheimer’s disease.
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Author: Press office
Source: King’s College London
Contact: Press Office – King’s College London
Image: The image is in the public domain.
Preliminary study: The findings are shown in Brain