Blocking a microRNA restores muscle mass in aged mice

Scientists at Elenae Therapeutics showed that inhibiting a specific microRNA (miR-128-3p) restores muscle mass and function in aged mice. MicroRNAs are small molecules that suppress protein production in cells. miR-128-3p appears to suppress a programme that keeps mitochondria (the energy producers of cells) active and keeps inflammatory signals low. As aging progresses, miR-128-3p increases, and muscle quality declines alongside it. The researchers blocked this microRNA using an antisense oligonucleotide, a synthetic molecule that binds to the microRNA and neutralises it.

More than just muscles

The treatment had effects beyond skeletal muscle. In mouse and pig models of Duchenne muscular dystrophy, it also improved cardiac function and limited harmful remodelling of the heart following a heart attack. This suggests that miR-128-3p drives a broader aging programme, not only muscle breakdown. The response across models was consistent: activation of mitochondrial programmes and suppression of inflammation and fibrosis (scar tissue formation).

From heart attack to age-related muscle loss

The company is currently focused on more severe indications such as cardiac damage and muscular dystrophy. That is typical: the more serious the indication, the faster regulatory approval may be possible. But the technology could in principle also apply to age-related muscle loss (sarcopenia). The rise of GLP-1 medications, which reduce weight but also lower muscle mass, has increased demand for such treatments.

The results are promising, but involve mice and pigs. Whether this works in humans, and whether it is safe, has yet to be established.

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