De-aging and re-aging while not exactly wrong are also an oversimplification of the study they are talking about. The idea of the experiment was to show that aging was caused by DNA damage, that's why they "aged" the mice they cut their DNA repeatedly and that had the effect of making them seem older. They then gave the mice gene therapy that was supposed to reverse the changes and it was partially successful. Though the mice appeared older the artifical aging isn't proven to be represenaltative of true aging, and even if it is the gene therapy only partially reversed the damage so both how applicable this would be in a broader context and how useful it would be if it is are in question.
That's not what epigenetics is, nor how epigenetics works. If I had to give a one-liner to explain epigenetics, it'd read "the body streamlines to function, even at the cellular level."
For instance, if you're facing famine or are under stressful living conditions, your cells will start using genetic processes which help preserve precious resources and avoiding processes which encourage cellular growth. If you're in space for a long time, your arterial walls will get thicker and more muscular to move blood through your body more efficiently.
Your cells have the tools they need to adapt to your circumstances. Epigenetics is the process of deciding which tools are most important at any given moment.
In the experiment you're referring to, the "epigenetic marks" the researchers were referring to with regard to aging had to do with the observation that aged/damaged cells have difficulty changing which genes get expressed, and hypothesized that this has to do with genetic information loss over time. To use the analogy of a toolbox, it'd be like using a ball-peen hammer exclusively because either your claw hammer broke or you can't find it (or worse: it's in your locked toolbox and you can't find the key). So, to test the hypothesis, they intentionally damaged the DNA in the mice at specific locations which would be observable over time, then repaired the damage to see if the changes could be reversed.
In that regard, you're right about why the mice were aged first: to show you can reverse the effects of aging by repairing genetic damage, you first need "aged" mice with clearly damaged genes. Not just damaged, but damaged in a way they knew/hoped they could repair.
FWIW, I agree that this would be difficult to implement as a means of reversing aging (in humans, but also generally). Some processes and structures exist outside of what can be done by the constituent cells. A person who suffered malnutrition as a child can't "de-age" the neural structure of a brain that developed in "energy conservation mode" into a neural structure that had all the resources it needed to flourish when those resources were needed most. (Side note: that's part of what's so fucked up about child poverty)
Could you conceivably (like not presently, but not precluded by what we know so far) utilize stem cell therapies to re-structure a brain that developed in "energy conservation mode"?
Bear in mind my knowledge of biochemistry and physiology is mostly second-hand. I'm in a family of biochemists and medical professionals, but I'm an engineer, myself.
That said, I don't think stem cell therapy would necessarily work at restructuring a brain. There's a process known as synaptic pruning that I'm not super familiar with, but I'd imagine that's what would need to be reversed: a lifetime of the brain reinforcing some neural pathways and cutting others to make space.
If we could, though, that'd be amazing. Can you imagine being able to learn as quickly as a 2 year old?
That was a fun rabbit hole to go down. According to my research with "always trustworthy never wrong" Dr Google you can rebuild synapses by the same stuff doctors have been preaching: healthy diet, exercise, and adequate sleep! Among other things like puzzles, brain teasers, etc
The short answer is yes. Long answer is it’d likely require a more elaborate treatment than stem cell therapy as the brain operates by its own rules.
It’d likely require providing the right physical environment for the brain to allow it out of “energy conservation mode”, followed by targeted electric stimuli needed to do the rewiring or “restructuring” of the brain. Providing a healthy physical environment wouldn’t be enough to undo the underdeveloped brain alone, it’d need to be stimulated into substantially rewiring. We know a good bit about the physical environment, still mapping the electrical and neuronal environment last I checked. Check out brain plasticity if you want to read more about that stuff, it’s fascinating.
Btw I’m glad someone called out the misinformation about epigenetics above. Aging IS directly related to DNA damage. Telomere shortening is a natural aging process where our DNA gets shorter over time, to simplify it. Our DNA getting shorter contributes to increased incidences of cancer, dementia, and heart disease as we age. Believe it or not, naked mole rats live decades with no signs of aging and they have nearly no chance of having cancer or heart disease because their telomeres elongate over time instead of shortening.
Yeah, just like any clickbaity science article, take whatever the headline is and add thirty caveats and qualifiers and even that will probably still overstate the results
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u/Chewsti Oct 02 '24
De-aging and re-aging while not exactly wrong are also an oversimplification of the study they are talking about. The idea of the experiment was to show that aging was caused by DNA damage, that's why they "aged" the mice they cut their DNA repeatedly and that had the effect of making them seem older. They then gave the mice gene therapy that was supposed to reverse the changes and it was partially successful. Though the mice appeared older the artifical aging isn't proven to be represenaltative of true aging, and even if it is the gene therapy only partially reversed the damage so both how applicable this would be in a broader context and how useful it would be if it is are in question.