January 17, 2022
B Cell Biomarkers for Alzheimer’s Disease
Alzheimer’s disease, a progressive neurodegenerative disease characterized by cognitive decline, is one of the greatest medical challenges for clinicians.
There are multiple theories for the exact molecular mechanisms that cause Alzheimer’s disease, including the classic plaque formation theory, and a host of potential catalysts including head trauma, genetic predisposition, thyroid disease, and more.
With such heterogenous causes of Alzheimer’s, and its exact molecular mechanisms unknown, developing diagnostic tests and therapies for this disease is a significant challenge.
Looking for New Biomarkers
One hope is that identifying biomarkers that predict whether someone will develop Alzheimer’s or diagnose the stage of their disease will eventually allow for early therapeutic interventions. Early intervention in this disease is critical because the damage caused to the brain by its progression is irreversible.
Some biomarkers have already been identified for Alzheimer’s and have helped shed light on some of the neurodegenerative processes that may be behind this disease. These include testing cerebrospinal fluid (CSF) for the proteins beta-amyloid 42, tau, and phospho-tau, proteins that are components of the characteristic plaques and tangles found in the brains of Alzheimer’s patients.
B Cell Biomarkers Uncovered by scRNA-Seq Analysis
The procedure to collect CSF via spinal tap is invasive and painful for patients. New hope comes in research recently published in Experimental & Molecular Medicine where authors used single-cell RNA sequencing (scRNA-seq) on blood samples to find new biomarkers for Alzheimer’s disease.
The authors specifically looked at peripheral blood mononuclear cells (PBMCs), a collection of immune cells that circulate in the blood and have been reported to be involved in neurodegeneration.
Interestingly, they detected a significant decrease in B cells in the blood of Alzheimer’s patients compared to controls, and that the reduction in B cells correlated to the severity of their dementia progression.
Increasing the resolution of their analysis, the researchers uncovered 18 genes that were specifically upregulated and 7 genes that were specifically downregulated in B cells as Alzheimer’s disease progressed, and several of the genes correlated closely with Alzheimer’s progression, providing a promising new molecular signature of Alzheimer’s and its underlying biology.
The Future of Alzheimer’s Diagnostics
As more is discovered about the underlying biology of Alzheimer’s disease and how to detect it as early as possible, the easier it will be to develop treatments and potentially cures for this debilitating neurodegenerative disease.
Bioinformatic analysis of scRNA-seq data was critical to uncovering these new B cell biomarkers and can be applied to other cell subpopulations to reveal more information about the underlying neurodegenerative processes at work.
Jane Cook, Journalist & Content Writer, Bridge Informatics
Jane is a Content Writer at Bridge Informatics, a professional services firm that helps biotech customers implement advanced techniques in the management and analysis of genomic data. Bridge Informatics focuses on data mining, machine learning, and various bioinformatic techniques to discover biomarkers and companion diagnostics. If you’re interested in reaching out, please email [email protected] or [email protected].
Sources:
https://www.nature.com/articles/s12276-021-00714-8
https://www.nia.nih.gov/health/biomarkers-dementia-detection-and-research
