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Aging muscle stem cells shift from rapid repair to long-term survival

phys.org

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Re: Aging muscle stem cells shift from rapid repair to long-term survival

#2
Original article: "Cellular survivorship bias as a mechanistic driver of muscle stem cell aging" - https://www.science.org/doi/10.1126/science.ads9175

Abstract: "Aging is characterized by a decline in the ability of tissue repair and regeneration after injury. In skeletal muscle, this decline is largely driven by impaired function of muscle stem cells (MuSCs) to efficiently contribute to muscle regeneration. We uncovered a cause of this aging-associated dysfunction: a cellular survivorship bias that prioritizes stem cell persistence at the expense of functionality. With age, MuSCs increased expression of a tumor suppressor, N-myc down-regulated gene 1 (NDRG1), which, by suppressing the mammalian target of rapamycin (mTOR) pathway, increased their long-term survival potential but at the cost of their ability to promptly activate and contribute to muscle regeneration. This delayed muscle regeneration with age may result from a trade-off that favors long-term stem cell survival over immediate regenerative capacity."

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#3
> Aging muscles heal more slowly after injury—a frustrating reality familiar to many older adults.

> In skeletal muscle, this decline is largely driven by impaired function of muscle stem cells (MuSCs)

I take it that as mitosis (cell division) gets slower with age, there's also simply no way aging muscles could potentially not heal more slowly?

So slower mitosis and then in addition to that muscle cells going into a "less repair, more survival" mode. Darn, sucks to get old.

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#4

> Aging muscles heal more slowly after injury—a frustrating reality familiar to many older adults. > In skeletal muscle, this decline is largely driven by impaired function of muscle stem cells (MuSCs) I take it that as mitosis (cell division) gets slower with age, there's also simply no way aging muscles could potentially not heal more slowly? So slower mitosis and then in addition to that muscle cells going into a…

No known mechanism, but cross species checks would imply that the schedule was evolved and has some control mechanism.

Species that evolved before the Devonian period tend not to age and instead grow through their entire lives. There is no mechanistic understanding for the wild variation in species lifespans.

So the natural question in these studies is what would happen if we simply told the muscles not to age this way. It’s plausible that this aging schedule evolved due to other factors independent of the biological constraints. It’s also plausible that evolution removed some other important components for longer lived stem cells.

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#5
post #4

> Aging muscles heal more slowly after injury—a frustrating reality familiar to many older adults. > In skeletal muscle, this decline is largely driven by impaired function of muscle stem cells (MuSCs) I take it that as mitosis (cell division) gets slower with age, there's also simply no way aging muscles could potentially not heal more slowly? So slower mitosis and then in addition to that muscle cells going into a…

No known mechanism, but cross species checks would imply that the schedule was evolved and has some control mechanism. Species that evolved before the Devonian period tend not to age and instead grow through their entire lives. There is no mechanistic understanding for the wild variation in species lifespans. So the natural question in these studies is what would happen if we simply told the muscles not to age this w…

Interesting, the Devonian also appears to be the period at which fish started sporting limb like appendages and muscle structures, and other animals started to explore land. Perhaps unlimited body growth doesn't work well for animals not entirely supported by water.

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#7
This makes me wonder if that line "I only got so many heart beats, I'm not going to waste them running" has some validity

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I thought Satchel Paige said it, but apparently not. He did say "I generally don’t like running. I believe in training by rising gently up and down from the bench. "

Which also fits the "don't prematurely age the stem cells"

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#8

This makes me wonder if that line "I only got so many heart beats, I'm not going to waste them running" has some validity -- I thought Satchel Paige said it, but apparently not. He did say "I generally don’t like running. I believe in training by rising gently up and down from the bench. " Which also fits the "don't prematurely age the stem cells"

[deleted]

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#9

This makes me wonder if that line "I only got so many heart beats, I'm not going to waste them running" has some validity -- I thought Satchel Paige said it, but apparently not. He did say "I generally don’t like running. I believe in training by rising gently up and down from the bench. " Which also fits the "don't prematurely age the stem cells"

So Trump was onto something about conserving bodily energy?

https://www.cnn.com/2019/02/08/politics/donald-trump-exercis...

Re: Aging muscle stem cells shift from rapid repair to long-term survival

#10

This makes me wonder if that line "I only got so many heart beats, I'm not going to waste them running" has some validity -- I thought Satchel Paige said it, but apparently not. He did say "I generally don’t like running. I believe in training by rising gently up and down from the bench. " Which also fits the "don't prematurely age the stem cells"

Do you know if running causes a person to have more or less heartbeats in a given time span? I'm not particularly medically knowledgeable and not sure.
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