6 replies to this topic

[reason]

Researchers aiming to produce a mouse model of accelerated sarcopenia, the characteristic loss of muscle mass and strength that occurs with aging, instead found that depleting muscle stem cell populations had no effect on this condition. This implies that the loss of stem cell activity in muscle tissue associated with aging may not be all that important in the development of sarcopenia after all:

Sarcopenia affects millions of aging adults. Age-related loss of muscle mass and strength not only robs elderly people of the ability to perform even the most basic tasks of daily living, but also significantly increases their risk of suffering devastating injuries and even death from sudden falls and other accidents. The literature on aging research, particularly muscle aging, postulates a strong correlation between the loss and/or dysfunction of muscle stem cells and sarcopenia, the scientific term for the age-related loss of skeletal muscle mass and strength. Currently entire research programs are focused on developing muscle stem cell therapy to delay, prevent or even reverse sarcopenia.

[Researchers] developed an animal model that allowed them to deplete young adult muscle of stem cells to a level sufficient to impair muscle regeneration throughout the life of a mouse. They expected the mouse to be a model of premature muscle aging. "To our surprise, the mice aged normally; life-long depletion of skeletal muscle stem cells did not accelerate nor exacerbate sarcopenia. Our negative results show a clear distinction between therapeutic strategies that may effectively treat degenerative myopathies, such as dystrophies and cachexia, versus sarcopenia. While degenerative conditions are expected to benefit from a stem cell-based therapy, this does not appear to be a viable approach for treating age-associated muscle wasting. Hopefully, our work will help to refocus aging muscle research on new therapeutic targets to effectively maintain muscle function and prevent frailty in the elderly."

Link: http://uknow.uky.edu...cells-and-aging

View the full article at FightAging

[Mind]

One mouse study...interesting, but I wouldn't be so quick to downplay the loss of stem cell function (and muscle mass) in aging..

[corb]

An interesting discovery with a lot of implications.
Now it would be good if someone were to replicate the experiment, and potentially test it on other tissues before we jump to conclusions - although I have to say experiments with similar results have been surfacing lately even if they weren't organized in the exact same manner.

 

It seems somatic cells functioning properly is the key to regeneration and not just in muscle tissues. So blasting yourself with stem cells and expecting anything to happen is a no go, I'm sorry to say - especially to the people on these forums which have done exactly that.

 

http://stemcellres.com/content/5/2/43

 

However, the overall efficacy of stem cell transplantation has been greatly hampered by several pathological conditions such as aging, diabetes, and obesity.

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It is noteworthy that the overall efficacy of stem cell transplantation relies on the activity of donor cells and tissue environment. Novel approaches aiming at reversing dysfunction of transplanted cells or refreshing target tissues should provide a useful avenue for improvement of cell therapy efficacy in patients with AMI. The findings reported in this work [1] that inhibition of IP6Ks turns on Akt signaling, decreases apoptosis, and modulates the paracrine profile in MSCs should shed some light on a better strategy in promoting the therapeutic efficacy of MSCs in aging.

 

http://stemcellres.com/content/5/3/79

 

Perturbations in specific cellular subpopulations, visible only on a single-cell level, represent a previously unreported mechanism for the dysfunction of diabetic ASCs. These data suggest that the utility of autologous ASCs for cell-based therapies in patients with diabetes may be limited and that interventions to improve cell function before application are warranted.

 

[Avatar of Horus]

Based on my readings of the scientific literature I had the impression that the main view is that the stem cells in the skeletal muscle, the satellite cells are responsive only for the regenerative process that gets activated upon injury, like with exercise. That is this tissue is not a mitotic homeostasis tissue, unlike e.g. the skin or the blood. And with aging the stem cells fail to activate properly, i.e. as if they were not present.
And this view seems to be in agreement with the findings of the study. As already its title says:
Inducible depletion of satellite cells in adult, sedentary mice impairs muscle regenerative capacity without affecting sarcopenia

http://www.nature.co...ll/nm.3710.html

Edited by Avatar of Horus, 08 January 2015 - 12:53 PM.

[corb]

Based on my readings of the scientific literature I had the impression that the main view is that the stem cells in the skeletal muscle, the satellite cells are responsive only for the regenerative process that gets activated upon injury

 

From my reading that is the case for most types of stem cells.

[Avatar of Horus]

Based on my readings of the scientific literature I had the impression that the main view is that the stem cells in the skeletal muscle, the satellite cells are responsive only for the regenerative process that gets activated upon injury

 
From my reading that is the case for most types of stem cells.

My post was a response to the article quoted and linked in the first post, and to the abstract of the study referred there.

[Avatar of Horus]

Based on my readings of the scientific literature I had the impression that the main view is that the stem cells in the skeletal muscle, the satellite cells are responsive only for the regenerative process that gets activated upon injury, like with exercise. That is this tissue is not a mitotic homeostasis tissue, unlike e.g. the skin or the blood. And with aging the stem cells fail to activate properly, i.e. as if they were not present.
And this view seems to be in agreement with the findings of the study. As already its title says:
Inducible depletion of satellite cells in adult, sedentary mice impairs muscle regenerative capacity without affecting sarcopenia
http://www.nature.co...ll/nm.3710.html

 

Based on my readings of the scientific literature I had the impression that the main view is that the stem cells in the skeletal muscle, the satellite cells are responsive only for the regenerative process that gets activated upon injury

 
From my reading that is the case for most types of stem cells.

My post was a response to the article quoted and linked in the first post, and to the abstract of the study referred there.

Here is what I meant:

...

...

From the article:
Stem cells, ageing and the quest for immortality
Thomas A. Rando - Nature 441, 1080-1086(29 June 2006)
http://www.nature.co...re04958_F1.html