What happens during brain aging and how can we tell if dementia is coming? Are there particular early hallmarks?
There are an increasing number of medical tests for predicting or detecting dementia. Alzheimer’s disease can often be detected early. But what do patients or their doctors do with such information?
Until recently there weren’t any treatments for dementia. Even a new approved drug for Alzheimer’s disease called Aducanumab comes with risks and not much benefit.
Early prevention is even better than trying to detect and treat unhealthy brain again. For that we need to better understand how brains age, normally and on the way to dementia.
With all of this in mind, let’s start our weekly review with two new papers on brain aging.
Brain aging and dementia
Plasma proteomic profiles predict future dementia in healthy adults, Nat. Aging. GFAP in blood plasma is a strong predictor of all-cause dementia. This is fascinating but why GFAP? Is it related to glial cells? Inflammation? A few other proteins were also strongly linked to dementia. The reasons aren’t yet clear but this is an exciting area of research.
Transcriptional and epigenetic dysregulation impairs generation of proliferative neural stem and progenitor cells during brain aging, Nat. Aging. A long-standing question is whether the aging human brain can make new neural stem cells that have functional meaning for brain health. Overall evidence supports some degree of proliferation and neurogenesis in the adult human brain. It’s less clear how many cells are generated and what those new cells do.
Thinking more interventionally, if you transplanted large numbers of neural precursors into an unhealthy, aging brain, could that improve brain health and function?
This is going to be a major area of research for decades to come.
More recommended reads
- Stem cell study offers clue to South Asians’ increased risk of cardiovascular disease, STAT News.
- The untapped potential of stem cells in menstrual blood, Pop Science. Another headline on this said these cells had “thrilling” potential.
- SHP-1 inhibition targets leukaemia stem cells to restore immunosurveillance and enhance chemosensitivity by metabolic reprogramming, Nat. Cell Bio.
- US businesses engaged in direct-to-consumer marketing of perinatal stem cell interventions following the Food and Drug Administration’s enforcement discretion era, Cytotherapy. This is from a UC Irvine team including Leigh Turner as first author. There are many hundreds of clinic firms just in the perinatal space. It’s good to see the FDA more active there but far more action by agency is needed.
- The rat with the big balls and the enormous penis – how Frontiers published a paper with botched AI-generated images, Science Integrity Digest. This is a weird example from Elisabeth Bik of what AI can do in publishing.
- Japan startup creates pigs with organs suitable for human transplants, Japan Times. “How suitable?” is the key question. From the piece, “Japanese startup PorMedTec announced on Tuesday that it has produced three clone piglets that have organs that can be transplanted to humans with less risk of immune rejection.” Other teams are working on this too in various animals including using CRISPR.
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Sell lab-grown meat in Tennessee, pay a $1 million fine, Vox. Finally, we have some craziness from Tennessee. Florida also has a bill to ban “fake meat.” Lab-grown meat seems to have become a political hot potato. I’m not necessarily advocating for synthetic meat but some of those strongly opposed to it seem to breaking with their past records of the mantra of letting markets decide on whether a product or company succeeds without government intervention.
Dear Admin:
In your diagram of the “burger stem cell”, your stem cell is gone after it divides, which is not the case for tissue stem cells that are being used for these “cultured meat” technologies. The diagram would be more accurate if the stem cell divided with an asymmetric self-renewal division – producing another stem cell and a committed meat progenitor cell – or if you drew two stem cells with one dividing like the one you drew and one dividing to produce another two stem cells.
Why am I bothering you with this seemingly academic minutiae? Because it is not minutiae for one of the biggest hidden problems faced by the cultured meat industry; and most of the companies in this struggling industry don’t even recognize it or understand it when it is explained to them. ALL of their cultures based on natural tissue stem cells eventually stop expanding (Believe me, this they know and are struggling to address it.) no matter what they do, because in cell culture the inherent asymmetric self-renewal program of tissue stem cells leads to their dilution to non-existence among their amplifying committed progeny cells when cultures are expanded by continuous splitting to make more cultures.
Even if these companies ever figure out how to solve the high cost of media to make producing cultured meat a profitable business with generally affordable products and how to evade political opposition, they will fail if they do not recognize and address this biological limitation of cell production dependent on natural tissue stem cells.
Conceptually, there are at least two solutions to the tissue stem cell expansion problem.
1) Controlled suppression of the asymmetric cell kinetics (SACK) of the tissue stem cells responsible for meat cell production. [My past laboratory originated and published the first demonstration the SACK concept in 2003 before racists kicked me out of MIT in 2007.]
2) An iPSC approach with an with indefinite expansion of iPSCs (they don’t dilute in their undifferentiated cultures because they lack asymmetric cell kinetics) that can be effectively differentiated on demand into the desired meat cells.
James @ Asymmetrex®