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An anti-aging strategy that works in mice is about to be tested in humans

221 points| molecule | 8 years ago |scientificamerican.com | reply

64 comments

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[+] codingdave|8 years ago|reply
There are quite a few comments skeptical about whether this would actually prolong life, but that result is not the only possible benefit. Even keeping our same lifespan, but not picking up age-related diseases, aches and pains, and blindness would be a huge benefit to older folk. (And I mean those of us in our 40s and 50s, who already curtail activities due to aging, not just people over 80.)

Seriously, having been though some health problems, and seeing how much your quality of life can suffer, I think some people would willingly take a slightly shorter lifespan for increased quality of life as we age.

Are these drugs the answer? I have no clue. But the direction of the research is encouraging, no matter how long we all live.

[+] zild3d|8 years ago|reply
Health span over life span
[+] JPLeRouzic|8 years ago|reply
In general in biology there is a simple criteria about the interest of an article:

- If it is tested in vitro, not only those results do not translate to human health issues (it is not in a living tissue which is a complex milieu, not simply the juxtaposition of cells), but commercial cell lines are not representative of normal cells, as they reproduce indefinitively.

- If it is tested on a mammalian animal model, it better but obviously mammalian species are different from each other at the organe level (for example the tail is used for thermoregulation in mouses).

- The best thing for evaluating any human impact, is a phase III of a clinical study.

[+] reasonattlm|8 years ago|reply
This is largely a promo for Unity Biotechnology and the associated labs. It fails to mention, e.g. SIWA Therapeutics and their work on antibodies, Oisin Biotechnologies and their gene therapy DNA constructs for destroying cells based on internal chemistry, the company that David Sinclair is starting for senolytics, that Betterhumans has beaten Unity to the punch and is currently running phase 0 human pilots of dasatinib and quercetin on a non-profit basis. Also that senescent cell clearance didn't magically spring into being in 2011, but appears clearly in Aubrey de Grey's position paper on human rejuvenation in 2002, and the Methuselah Foundation, SENS Research Foundation, and others have been advocating hard for more work in this direction in the face of a research community that rejected it for a decade.

But hey, if you beat the competitors to be the first to raise 9-figure sums of venture capital, then you too can engineer attention to shine on you only, and rewrite history more or less as you like for a while.

So far all ways to address aging in mice have slowed aging by tinkering with metabolism, but slowing down the damage accumulation. They all produce much larger effects in short-lived species, probably because long-lived species have evolved to have many of these metabolic items turned on already. Calorie restriction extends life by 40% in mice, and I can assure you that while it is pretty beneficial in humans, you are not going to add more than a couple of extra years. Senescent cell clearance is the first way to address aging that involves repair of damage rather than slowing it down: we have no idea how the size of benefit in mice will translate to humans. So 25% gains in mice can be exciting here, whereas for any slowing-aging-only approach it would be a yawn.

[+] dawhizkid|8 years ago|reply
Isn't this yet another case for keto/intermittent fasting? It is well known that in a fasting state you trigger cell autophagy -> essentially force healthy cells to eat dead or diseased cells for energy...
[+] dawhizkid|8 years ago|reply
And btw...fasting is free, safe when done properly, and something anyone can do today

I would much rather fast than ingest a drug pushed by big pharma...even if it did work and triggered the same response

[+] gojomo|8 years ago|reply
The longevity benefits of fasting/caloric-restriction also appear to work through the clearing of some cells ('autophagy'); see for example:

https://en.wikipedia.org/wiki/Autophagy#Caloric_restriction

[+] andai|8 years ago|reply
<Conjecture> if you were a hungry body, which cells would you cannibalize first, healthy cells or old malfunctioning troublemakers?
[+] lettergram|8 years ago|reply
Took me a while to find, but this method apparently only increases the life span of mice by 25%. Given how mice are prey animals - i.e. they aren't meant to live long - I don't anticipate the same results with Humans. Although, it may help reduce risks of diseases.

It'll be interesting to see results.

[+] diggernet|8 years ago|reply
Even if there is 0% increase in median lifespan, they describe many effects which would make aging a much less miserable and debilitating experience. That alone is a win. Take this bit:

"can restore lustrous hair and physical fitness to ageing mice"

Think of it! Finally, a cure for baldness! And, yeah, less of a decline in fitness would be nice, too.

[+] BurningFrog|8 years ago|reply
I'll take an "only" 20 year life span increase.
[+] stevenwoo|8 years ago|reply
I thought a huge part of the problem is mice are not that similar to humans (lots of things have different effects on mice versus humans) but mice are really easy/cheap to test with compared to larger mammals that are a bit closer to humans. We could be missing a lot by not testing stuff in humans that has zero/deleterious effect in mice.
[+] reasonattlm|8 years ago|reply
Some papers showing direct connections between senescent cells and specific aspects of aging, in many cases turning back that aspect by removing the senescent cells.

Osteoporosis: https://doi.org/10.1038/nm.4385

Fatty liver disease: https://doi.org/10.1038/ncomms15691

Disruption of platelet formation: https://doi.org/10.3389/fonc.2017.00188

Osteoarthritis: https://dx.doi.org/10.1038/nm.4324

Disruption of regeneration: https://doi.org/10.3389/fcell.2017.00049

Lung fibrosis: https://doi.org/10.1183/13993003.02367-2016

Pulmonary function in general, including tissue elasticity: https://doi.org/10.1172/jci.insight.87732

Atherosclerosis: http://dx.doi.org/10.1126/science.aaf6659

Vascular calcification: http://dx.doi.org/10.18632/aging.101191

Chronic kidney disease: https://doi.org/10.18632/oncotarget.17327

Cardiac hypertrophy: https://doi.org/10.1371/journal.pone.0182668

Cardiac fibrosis and function in general: https://doi.org/10.1093/eurheartj/ehx454

[+] amelius|8 years ago|reply
I would be surprised if people weren't already testing this, e.g. in China where there is less regulation.

I think that could be a trend: US/European researcher publishes hypothesis, and Asian researcher secretly tests it on humans, and if it works, publishes it and/or becomes first to market.

[+] cvsh|8 years ago|reply
What do you think the solution would be, should this take off? Wrapping early stage trials in a veil of secrecy?
[+] maga|8 years ago|reply
I wonder if exercising contributes to killing off these senescent cells. In muscle building one is breaking down and rebuilding muscle cells, this might as well prevent cell "aging" and going into senescence.
[+] rsync|8 years ago|reply
"I wonder if exercising contributes to killing off these senescent cells. In muscle building one is breaking down and rebuilding muscle cells, this might as well prevent cell "aging" and going into senescence."

I think this is already known and understood - at least with muscle and bone cells. My understanding was that by putting energy production stresses on your cells, you weed out the ones that perform poorly. Specifically, you weed out those cells whose mitochondria are less efficient at producing energy.[1]

So there is a selection process that takes place, over time, in your own cell population.

I find this very interesting but I have also grown very pessimistic about its import ... people that don't like exercising will do anything not to exercise so it really doesn't matter.

We don't need any new findings that demonstrate the (clear, obvious, nearly immediate) benefits of exercise. What we need are fewer cars and more walking.

[1] I highly recommend Nick Lanes first two books - _Oxygen_ and _Power, Sex, Suicide: Mitochondria and the Meaning of Life_.

[+] lukka5|8 years ago|reply
Maybe exercising increases activity in the inmune system which contributes to killing more senescent cells?
[+] tomohawk|8 years ago|reply
Just thinking about the societal implications of this. For example, death is one of the few things that causes turnover in the Senate.

It seems ironic that the mechanism here (killing off old cells) enables humans to live longer, thereby possibly enabling these same humans to case society to age.

[+] api|8 years ago|reply
Life extension will be horribly dystopian unless we can also find ways to restore neuroplasticity and enable re-learning-- a kind of "second childhood." Otherwise it'll be a bunch of immortal old curmudgeons sitting on top of society saying "get off my lawn!"

Personally I'm not sure I'd even want too much life extension without neuroplasticity restoration and quality of life extension. I'd rather be dead than walking dead.

[+] ImSkeptical|8 years ago|reply
I'll take immortality and term limits, please.
[+] summer_steven|8 years ago|reply
Not going to prevent aging as well as people think.

As cells age, the risk for mutations occuring when they divide increases. The reason these cells stop dividing and become senescent is because dividing elderly cells poses a high cancer risk.

I think this may buy the trappings of youth (plump skin, clear eyes, etc) at the cost of a higher risk of cancer.

[+] manmal|8 years ago|reply
Yes, but the remaining non-senescent cells are obviously not damaged too much, and thus CAN divide - perhaps they did not divide as often in their lifetime, their ancestors were not as stressed, or their DNA was not compromised. If you make room for those cells to divide, that should be a good thing.
[+] naveen99|8 years ago|reply
gametes never really stop dividing...
[+] batrat|8 years ago|reply
Where do I sign up? (-:
[+] trthomps|8 years ago|reply
Where's the catch?
[+] jlebrech|8 years ago|reply
7 Billion humans
[+] grondilu|8 years ago|reply
The catch is that it will take a lot of time until this kind of study gives definitive results. People already live quite long, so longevity studies are usually multi-generational.
[+] ars|8 years ago|reply
Summary: Kill cells that have stopped dividing, but that are still alive. (Called: Senescent cells.)

Don't prevent them from entering this state (which could cause tumors), just kill them if they do enter this state.

Hard part: Each organ/tissue has different types of cells, so each needs a unique medication to kill those cells.

[+] lsh|8 years ago|reply
are you an auto-summary bot?