A naturally occurring molecule in the body could help reverse muscle ageing and reduce frailty in older adults, a new study suggests.
Scientists found that prostaglandin E2 (PGE2), a chemical messenger in the body, can restore the function of aged muscle stem cells – the cells responsible for repairing damaged muscle tissue.
The research suggests a single dose of treatment may be sufficient to improve muscle regeneration and strength in older individuals, potentially preventing sarcopenia – a condition characterised by low muscle mass and increased risk of frailty and mobility issues.
Gradual muscle loss in older adults is often worsened by the body’s limited capacity to recover from injury, particularly after falls or surgery. Muscle stem cells are known to play a central role in tissue repair, but they become less effective with age.
Researchers examined the effects of PGE2 and a related receptor molecule, EP4. In young mice, PGE2 is naturally released during injury to prompt muscle stem cells to regenerate tissue. However, in aged mice, production of EP4 in muscle stem cells was found to be either missing or reduced by half compared to that in young mice.
“PGE2 is an alarm clock to wake up the stem cells and repair the damage. Ageing essentially reduces the volume of the alarm and the stem cells have also put on ear plugs,” said study author Yu Xin Wang.
The study showed that administering a stable form of PGE2 to older mice after muscle injury, combined with exercise, led to greater muscle mass and strength compared to untreated animals.
“What amazes me most is that a single dose of treatment is sufficient to restore muscle stem cell function, and that the benefit lasts far beyond the duration of the drug,” said Dr Wang. “In addition to making new muscle, the stem cells stay in the tissue, where they sustain the effect of the PGE2 and instil the muscle with further capacity to regenerate.”
The treatment was also shown to reverse many of the age-related changes in mouse muscle. The researchers said this approach could have wider potential for ageing tissues beyond muscle.
“PGE2 has been implicated in the regenerative process and signalling for the intestine, liver, and several other tissues, potentially opening up an approach that could restore the renewing capacity of other aged tissues,” said Dr Wang.
“We have discovered that the PGE2 induces rejuvenation of aged muscle stem cells, which leads to functional improvements in muscle repair and strength,” the researchers concluded.