I’m a bit late posting this after getting caught up in some sample preparation, grant writing, and general life things, but it felt like the right time to add my first update.
A few really exciting things have happened since I was here last!
Impact of aging on murine mitochondrial DNA
A highly collaborative project I contributed to during my PhD has been published in eLife as of February 17, 2023!
The multi-tissue landscape of somatic mtDNA mutations indicates tissue specific accumulation and removal in aging.
In short, we found that mtDNA mutations in aging mice differ among individuals and between organ systems within the same mouse.
Also check out the Insight article written as a companion to the manuscript: Mitochondrial DNA: Are some mutations more equal than others? A large-scale study of mutations in mitochondrial DNA has revealed a subset that do not accumulate with age.
Antibody-free isolation of circulating membrane-bound particles from plasma
There’s a really exciting new technique I worked on as part of the MacCoss lab called Mag-Net!
Dr. Christine Wu developed Mag-Net to simultaneously isolate circulating membrane-bound particles from plasma and deplete high abundance plasma proteins (ALB, TF, etc.) using ReSyn SAX magnetic beads!
bioRxiv preprint: Mag-Net: Rapid enrichment of membrane-bound particles enables high coverage quantitative analysis of the plasma proteome
Although we have more biophysical characterization that we’d like to do, we hypothesize Mag-Net is capturing a mixture of extracellular vesicles (EVs) including exosomes and microvesicles based on the following findings:
- Proteome markers including (but not limited to!) CD9, CD40, CD63, CD81, FLOT1 and 2, BSG, TSG191, NCAM1, SEPTIN2, and ATP5F1A.
- Particle counting and size distribution concentrated between ~50-250 nm (diameter).
- Transmission electron microscopy (TEM) identifying lipid bilayers in particles.
Even if you aren’t specifically interested in EV biology, Mag-Net compresses the significant dynamic range of the plasma proteome by depleting abundant proteins. I hope you’ll give it a try!
Cascadia Proteomics Symposium
Last week I attended my first Cascadia Proteomics Symposium (7/18-7/19/2023) at the Institute for Systems Biology in Seattle, WA.
It was fantastic to meet more of the proteomics and mass spectrometry community in the Pacific Northwest, including representatives from Oregon, Washington, and Canada.
I was fortunate to have the opportunity to present recent pilot data using Mag-Net in humans, mice, and companion dogs. My goal is to translate this work to examining the aging EV proteome across the lifespan in all 3 species.