> Do we currently have the ability to do targeted methylation or de methylation at sites in cells?
No, and you probably wouldn’t want it if you could. You don’t know what mutations are lurking in the genes that have been switched off or the consequences of turning them back on.
I’ve thought about this a bit, and what resetting the methylation map really requires, in addition to actually resetting that map, is resetting your genome to a known good state.
That’s pretty radical, but to selectively switch methylation on and off with precision you’re already talking about science beyond anything we have, featuring custom engineered constellations of proteins that unwrap your chromatin from around histones and then walk along it changing methylation state, then pack everything back.
And doing it for each cell type, without applying the wrong map anywhere.
And knowing what all the cell types and their correct methylation maps actually are.
And assuming that methylation isn’t used anywhere, for example in the brain, in a way we don’t expect.
And methylation isn’t the only kind of epigenetic modification.
So, if we’ve solved all of those problems, rebuilding your DNA to a clean, mutation free state at the same time should be a breeze.
We really do need AI for this if any of it is going to be remotely feasible.
I just don't understand. Wouldn't we have evolved in an environment with constant stress? Constant fear of disease, starvation, predation, attacks by neighboring tribes? Why would our body's natural response to our environment be to immediately grenade itself.
I'm no biologist, but it's pretty easy to imagine a plausible mechanism.
Stress doesn't cause your body to "immediately grenade itself", it causes gradual problems over an extended period. But you can imagine that evolutionarily speaking, a stressful situation would frequently be a situation involving imminent danger. A response that prioritizes short-term survival (e.g. releasing adrenaline and cortisol) regardless of the long-term consequences could easily improve evolutionary fitness.
Considering that aging only happens later in life, it wouldn't have much of an effect on how efficient humans produce offspring, so it wouldn't be selected against. It is the same explanation for why Huntington's and Alzheimer's are still around.
What about Xanax or medication. Hypothetically ignoring the ill effects of the drugs themselves will chemical stress relief have the same anti-aging benefits?
I suspect that epigenetic aging is adaptive; a deliberately programmed sequence wherein genes more likely to contribute to age-related mortality are shut down progressively. This being in response to random genetic damage accumulating at a predictable rate.
What we think of as aging then becomes primarily the epigenetic response to the problem of DNA damage, much like the symptoms of a virus are mostly the result of the immune response rather than the virus’s direct effects.
There's a lot of indirect evidence for this from the fact that some naive attempts at stopping aging give you cancer, like turning telomerase on indiscriminately.
Almost everything in nature has multiple functions or causes, but one cause of aging is probably an evolutionary compromise between longevity and not getting cancer.
One option, I guess, would be turning the guard rails off and just getting incredibly good at treating cancer or inventing some extraneous cancer detection and killing mechanism.
It’s rarely such a simple tradeoff that only two things are being optimized. Humans live way longer than wolves for example despite being of similar body mass.
Cancer is extremely rare as a cause of death in wild animals. Again is more common but late enough that reproduction has produced multiple offspring.
Energy expenditure isn’t something we’re concerned with but drives a great deal of evolutionary optimization.
Do we currently have the ability to do targeted methylation or de methylation at sites in cells?
No, and you probably wouldn’t want it if you could. You don’t know what mutations are lurking in the genes that have been switched off or the consequences of turning them back on.
I’ve thought about this a bit, and what resetting the methylation map really requires, in addition to actually resetting that map, is resetting your genome to a known good state.
That’s pretty radical, but to selectively switch methylation on and off with precision you’re already talking about science beyond anything we have, featuring custom engineered constellations of proteins that unwrap your chromatin from around histones and then walk along it changing methylation state, then pack everything back.
And doing it for each cell type, without applying the wrong map anywhere.
And knowing what all the cell types and their correct methylation maps actually are.
And assuming that methylation isn’t used anywhere, for example in the brain, in a way we don’t expect.
And methylation isn’t the only kind of epigenetic modification.
So, if we’ve solved all of those problems, rebuilding your DNA to a clean, mutation free state at the same time should be a breeze.
We really do need AI for this if any of it is going to be remotely feasible.
Relevant video by Kurzgesagt – In a Nutshell: https://www.youtube.com/watch?v=Mo1A45ShcMo
Stress doesn't cause your body to "immediately grenade itself", it causes gradual problems over an extended period. But you can imagine that evolutionarily speaking, a stressful situation would frequently be a situation involving imminent danger. A response that prioritizes short-term survival (e.g. releasing adrenaline and cortisol) regardless of the long-term consequences could easily improve evolutionary fitness.
[0]: https://www.forbes.com/sites/tracybrower/2024/09/15/how-bein...
What we think of as aging then becomes primarily the epigenetic response to the problem of DNA damage, much like the symptoms of a virus are mostly the result of the immune response rather than the virus’s direct effects.
Almost everything in nature has multiple functions or causes, but one cause of aging is probably an evolutionary compromise between longevity and not getting cancer.
One option, I guess, would be turning the guard rails off and just getting incredibly good at treating cancer or inventing some extraneous cancer detection and killing mechanism.
Cancer is extremely rare as a cause of death in wild animals. Again is more common but late enough that reproduction has produced multiple offspring.
Energy expenditure isn’t something we’re concerned with but drives a great deal of evolutionary optimization.
Yes, and proteinopathies, and likely lots else besides. We probably don’t even understand the failure modes that aging protects against.