Development of non-invasive research and diagnostics platform for Alzheimer's disease based on plasma exosomes - PROJECT SUMMARY
Almost 6 million Americans currently live with Alzheimer's disease (AD), and this number is projected
to increase to 14 million by 2050. The consensus is arising in the field that in order to treat AD
effectively, early detection at the MCI stage is a must. Thus, there is a critical need for a novel
minimally invasive and cost-effective diagnostic assay capable of such early detection. Cell-secreted
extracellular vesicles (EVs) recently gained significant attention in the fields of liquid biopsy and AD
research. Within the scope of biomarker detection, EVs offer numerous benefits for clinical analysis,
including non-invasive collection, a suitable sample source for longitudinal disease monitoring, ability
to cross the blood-brain barrier, higher stability and sample volumes, faster processing times and
lower cost. Multiple reports linked EVs to neurodegeneration and have been able to couple exosomal
load in CSF to AD progression. However, the analysis of plasma exosomes and other EV has not
really been possible for early AD detection. The procedures for plasma biomarker analysis are very
long and cumbersome due to extremely low target levels and high background of free plasma
proteins. In order to enable better biomarker discovery and AD diagnosis, a more reliable and
efficient approach is needed, capable of enriching potential AD-associated proteins with higher purity.
In this NIH SBIR Phase I study, we will develop a novel method for fast and reproducible capture and
isolation of EVs with >95% recovery yield and >99.9% purity from plasma samples. We propose to
implement this EV capture approach to detect and quantify the presence of common AD markers
(amyloid-ß, p-tau) in plasma EVs, and for discovery of new protein and phosphoprotein biomarkers in
plasma EVs. We will also correlate and match their levels in CSF EVs and as soluble proteins to
evaluate the clinical relevance of using plasma EVs as the source for diagnostics. The following aims
will be completed in the Phase I of the proposal: Aim #1: Develop and validate the EVtrap method for
plasma EV isolation and purification. Aim #2: Implement EVtrap for detection of common AD
biomarkers in plasma and CSF exosomes. Aim #3: Develop EVtrap for discovery of plasma exosome
proteins and phosphoproteins as new AD biomarkers. By the completion of this project, EVtrap
capture beads method will be optimized, an AD biomarker discovery platform from plasma EVs will
be developed, and a minimally invasive early Alzheimer's disease detection assay will be validated
that can overcome the limitations of current approaches, and thus could have an enormous public
health impact and market potential.
