BIOPEXAL – Biomarkers in plasma exosomes for the early diagnosis of prodromal Alzheimer’s disease
El projecte BIOPEXAL estudia el potencial dels exosomes plasmàtics com a biomarcadors no invasius, per avaluar si aquests poden ser una eina de diagnòstic precoç i mètode de detecció primari d’Alzheimer
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Alzheimer’s disease is the most common form of dementia worldwide, and its prevalence is increasing exponentially. Differential diagnosis at the early stages of the disease remains one of the major challenges in routine clinical practice. The invasive nature and high cost of current Alzheimer’s diagnostic techniques have sparked growing scientific interest in plasma biomarkers, particularly plasma exosomes. The plasma-based nature of these biomarkers means they can be obtained from blood plasma through a simple routine blood test, making them more accessible and less invasive than neuroimaging studies, PET radiotracers, and cerebrospinal fluid biomarkers.
Exosomes: extracellular informants
Exosomes are extracellular vesicles synthesised by most cells and play an important role in cell-to-cell communication. This means they carry information from all cells in the body and facilitate intercellular communication. Exosomes are secreted by cells and contain nucleic acids (RNA) and proteins specific to their cell of origin, reflecting not only the cell type from which they derive but also its functional state. Recent scientific evidence indicates that exosomes present in the blood (plasma exosomes) are capable of reflecting the molecular alterations that occur at the central level during the different stages of Alzheimer’s disease development and could therefore serve as peripheral biomarkers of the disease.
By analysing exosomal content, the aim is to identify a protein pattern indicative of different stages of cognitive impairment and of whether or not it progresses to Alzheimer’s disease. Differences in the biomarker profiles of exosomes from patients with mild cognitive impairment who progress to Alzheimer’s disease compared with those who do not may be key to achieving an early differential diagnosis.
Why was the BIOPEXAL project designed?
The BIOPEXAL project has two main objectives:
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To evaluate the potential of plasma exosomes as a tool for the early diagnosis and monitoring of Alzheimer’s disease.
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To evaluate the potential of plasma exosomes as a mechanism for the propagation of Alzheimer’s pathological hallmarks.
Biomarker profile of plasma exosomes
The first phase of the project is conducted at Ace Alzheimer Center Barcelona and focuses on studying the protein content of plasma exosomes from patients at different stages of the disease (individuals with subjective memory complaints, mild cognitive impairment, and Alzheimer’s disease–related dementia). The procedure involves isolating exosomes from plasma samples and measuring the concentrations of 184 proteins involved in Alzheimer’s disease and associated with inflammation and neurodegenerative processes. The goal is to assess whether a plasma exosome biomarker pattern exists that allows early identification of patients with mild cognitive impairment who will progress to dementia and those who will not.
Potential for propagation of Alzheimer’s pathological hallmarks
The second phase of the study is carried out in the laboratories of the University of Barcelona (UB) and examines the role of plasma exosomes in the spread of Alzheimer’s disease–related molecular alterations throughout the brain. The procedure involves isolating plasma exosomes from patients with Alzheimer’s disease and incubating them in in vitro and in vivo models. This approach aims to determine the influence of exposure to exosomes from different disease phenotypes on cellular molecular mechanisms and to assess the resulting cognitive and memory impairments.
Relevance of the BIOPEXAL project
Scientific and therapeutic research: BIOPEXAL is expected to have a significant impact on the search for new diagnostic strategies based on the early identification of dementia development, as well as on the standardisation of protocols for preventive interventions. The project has the potential to advance the fields of Alzheimer’s prognosis, early diagnosis and personalised treatment.
Socioeconomic impact: the identification of new plasma biomarkers will enable more cost-effective diagnoses, support better-informed medical decision-making, and improve therapeutic outcomes through early diagnosis and personalised treatment. Their value lies in being economically affordable, non-invasive for patients, and easily obtainable in any primary care setting, thereby helping to reduce the burden on healthcare systems and increase economic productivity.
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