I should add that much of the most encouraging progress is in the area of xenotransplantation/stem cell transplantation, artificial organs, and neuronal replacement therapy (it’s already being done for Parkinson’s, though regeneration of the basal ganglia may be easier than regeneration of the entire brain—the https://gage.salk.edu/ lab is particularly good to follow on this). You don’t need an entire mimic of the brain’s memory or identity to maintain the continuity of consciousness.
Gradual “chimerism” is an encouraging direction that does not require us to understand all kinds of age-related damage (eg https://twitter.com/biorxivpreprint/status/1314766530765295618 ). “chimerism”, broadly speaking, is inclusive of cells “transferring mitochondria” to other cells, cells “transferring telomere to other cells”, AAV’ing or CMV’ing genes [like enhanced SIRT6] from centenarians or bowhead whales into humans.
Even glial cells and astrocytes can be “reprogrammed” into neurons (though whether they will retain the information is another issue), and there are ways for cells to “expel” their aggregates/debris to be cleared up or removed by macrophages/astrocytes/cerebrospinal fluid (hell, even the Li-Huei Tsai lab has shown that playing 60Hz frequencies can help remove amyloid plaque from neurons). One of the real questions I have is whether there is a way for a cell to expel all kinds of intracellular junk, including the notoriously impliable lipofuscin and ceroid aggregates (there’s a kind of lipid/protein structure that is amenable to being engulfed by exosomes that can clear out the damage).
it’s important to note that bowhead whales can live to 200+ years even without obvious age-associated pathology, and we may be better prodded to build more “robust” mitochondria/cell membranes just by studying them (eg degree of membrane unsaturation seems anticorrelated to longevity in organisms like birds), and we can simply try to make our cell membranes less prone to ROS (one way is to incorporate deuterated PUFAs/omega-3′s), which somehow still does not get as much research as claimed [some degree of enhanced deuteration is also helpful for longevity].
Overall you want to maintain the cell’s ability to sense damage and to properly reduce this damage before it reaches high levels [genomic damage/mosaicism is the hardest to sense, but this is ultimately a more distal problem than more immediate problems that come from loss of proteostasis]
I should add that much of the most encouraging progress is in the area of xenotransplantation/stem cell transplantation, artificial organs, and neuronal replacement therapy (it’s already being done for Parkinson’s, though regeneration of the basal ganglia may be easier than regeneration of the entire brain—the https://gage.salk.edu/ lab is particularly good to follow on this). You don’t need an entire mimic of the brain’s memory or identity to maintain the continuity of consciousness.
https://www.nature.com/articles/s41536-017-0033-0?fbclid=IwAR2N4wjwAhHM3OXfGXV7QUNTUxFB3n275QO8-gDsA7qRkuL3ZeFVIrbyT5o https://www.frontiersin.org/articles/10.3389/fgene.2019.00310/full?fbclid=IwAR0RP6zGAUEBhphqk_t-rtIFEvHAo2c_PbPpmB-pPElnG20Tt1aiDx2vyLc
https://today.tamu.edu/2020/10/23/could-a-nasal-spray-of-nanovesicles-repair-brain-cells/?fbclid=IwAR0KP26TV-m4PWyhPs_PXMKNJIwWDwjulPtWndayJrdiNAqM2reUGgwkVM0
You don’t need a full understanding of aging to safely transmit stem cells or tissue from one organism to another, and there are scientists who are working on the immunorejection problem wrt non-allogenic stem cells (eg see https://www.pnas.org/content/116/21/10441?fbclid=IwAR0LXoEBoZ_7THOj3szfW3rpqb-wDMv0xxFHFYcHstZfY3hZl2kDXgYHSuw ).
Hell, some people [like Dave Asprey] already boldly inject themselves with stem cells (https://blog.daveasprey.com/how-adult-stem-cells-can-help-stop-pain-and-reverse-aging/ ) and while he doesn’t know what the hell he’s doing (and it seems like the FDA isn’t even holding him back from this), the experimentation provides great evidence for the rest of us.
Gradual “chimerism” is an encouraging direction that does not require us to understand all kinds of age-related damage (eg https://twitter.com/biorxivpreprint/status/1314766530765295618 ). “chimerism”, broadly speaking, is inclusive of cells “transferring mitochondria” to other cells, cells “transferring telomere to other cells”, AAV’ing or CMV’ing genes [like enhanced SIRT6] from centenarians or bowhead whales into humans.
Even glial cells and astrocytes can be “reprogrammed” into neurons (though whether they will retain the information is another issue), and there are ways for cells to “expel” their aggregates/debris to be cleared up or removed by macrophages/astrocytes/cerebrospinal fluid (hell, even the Li-Huei Tsai lab has shown that playing 60Hz frequencies can help remove amyloid plaque from neurons). One of the real questions I have is whether there is a way for a cell to expel all kinds of intracellular junk, including the notoriously impliable lipofuscin and ceroid aggregates (there’s a kind of lipid/protein structure that is amenable to being engulfed by exosomes that can clear out the damage).
it’s important to note that bowhead whales can live to 200+ years even without obvious age-associated pathology, and we may be better prodded to build more “robust” mitochondria/cell membranes just by studying them (eg degree of membrane unsaturation seems anticorrelated to longevity in organisms like birds), and we can simply try to make our cell membranes less prone to ROS (one way is to incorporate deuterated PUFAs/omega-3′s), which somehow still does not get as much research as claimed [some degree of enhanced deuteration is also helpful for longevity].
Overall you want to maintain the cell’s ability to sense damage and to properly reduce this damage before it reaches high levels [genomic damage/mosaicism is the hardest to sense, but this is ultimately a more distal problem than more immediate problems that come from loss of proteostasis]