Aging rewires muscle microRNAs, but calorie restriction (and perhaps rapamycin) reverses many of these changes

[RapAdmin]

Given the overlap of the mechanisms of action for rapamycin and caloric restriction, I suspect that the results would be very similar if rapamycin was tested in this way:

Impact of CR on miRNA expression. A bar chart showing the number of genes upregulated and downregulated in the muscle of aged rats fed ad libitum (AL), when compared to the muscle of old rats fed AL, and what percentage of these are normalised by caloric restriction (CR). Upregulated miRNAs: 17 (47.2%) were normalised by CR, 19 (52.8%) were unaffected by CR; Downregulated miRNAs: 17 (35.4%) were normalised by CR, 31 (64.6%) were unaffected by CR

Full paper (open access): miRNA changes with ageing and caloric restriction in male rat skeletal muscle: potential roles in muscle cell function

Related Reading:

• Why interventions such as calorie restriction and rapamycin slow the aging process: slowing cellular noise

• Calorie restriction and rapamycin distinctly mitigate aging-associated protein phosphorylation changes in mouse muscles

• Calorie restriction and rapamycin distinctly restore non-canonical ORF translation in the muscles of aging mice (Nature)

• Rapamycin, not metformin, mirrors dietary restriction-driven lifespan extension in vertebrates

• Rapamycin, Caloric Restriction, and Inflammaging

• Even with calorie restriction, rapamycin slows muscle aging

[relaxedmeatball]

In principle it’s interesting, but I think this is old news. Here’s a paper from 2013

Age-associated miRNA Alterations in Skeletal Muscle from Rhesus Monkeys...

It’s quite well known that CR mimics some aspects of anti-aging. However, these studies almost never use any sort of alternative diet or intervention as a control, so it’s not clear whether these are CR-specific.

One of these days I will try and do this experiment to look at the kinetics of changes. i.e. does a short term fast accomplish the same changes