A team in Fukuoka, Japan, just turned the body's own muscle-repair signal into what they're calling "Super HGF" — and it happened almost by accident.

  • Binding affinity to its target receptor increased by more than 2-fold compared with untreated protein
  • The effect appeared only at a molar ratio of 1:8,000, trisulfide to HGF
  • Two vulnerable sites on the protein, named Y198 and Y250, are where age-related damage strikes
  • Findings published July 24, 2026, in the journal Scientific Reports

The protein at the center of the discovery is hepatocyte growth factor, or HGF — a molecule that, despite its liver-sounding name, acts as a wake-up call for muscle repair throughout the body.

A Rusted Key in Aging Muscle

Skeletal muscle relies on dormant stem cells called satellite cells to repair damage from injury, exercise or everyday wear. HGF normally sits quietly in the tissue surrounding muscle fibers until it's released and binds to a receptor called c-met, rousing those satellite cells into action.

Aging disrupts that handoff. A research team led by Professor Ryuichi Tatsumi at Kyushu University's Faculty of Agriculture had previously shown that HGF can undergo a chemical change called nitration at two specific spots, Y198 and Y250 — the exact region the protein uses to grip its receptor.

"HGF is not necessarily missing as we age," Tatsumi explained. "Rather, it can be chemically altered after it is made."

"That led us to wonder whether a compound with strong antioxidant capacity might protect HGF, either by preventing nitration or by compensating for the functional loss it causes."

Once nitrated, HGF behaves like a rusted key that no longer fits its lock, leaving satellite cells asleep even when the body still produces plenty of the protein.

How Scientists Built "Super HGF"

The team tested two antioxidant sulfur compounds, glutathione trisulfide (GSSSG) and lipoic acid trisulfide (LASSS), both members of a chemical family prized for their unusual redox chemistry.

At typical concentrations, both compounds reduced nitration but didn't fully restore HGF's ability to bind c-met. So researchers pushed the molar ratio far higher, from 1:4,000 up to 1:8,000.

At that higher dose, LASSS alone produced a striking surprise: HGF's binding affinity for c-met more than doubled compared to untreated protein, while also becoming more resistant to nitration damage. GSSSG, tested side by side, showed no such boost.

"This exceeded our expectations," Tatsumi said of the result, describing the enhanced molecule as a form that "binds c-met more strongly and resists nitration" — effectively a strengthened version of the body's own repair signal.

Mouse Tests and What Comes Next

To check whether the effect held up outside a test tube, the team pretreated mice undergoing simulated muscle atrophy with LASSS. Those animals showed significantly less HGF nitration than untreated mice, again with no benefit from GSSSG.

Importantly, stronger receptor binding in mice and in lab dishes doesn't yet prove that muscle actually regenerates better or faster — that will require further studies in aging animals to confirm both safety and real-world effectiveness.

Still, the approach is notable for what it doesn't do: rather than introducing a new drug from scratch, it protects and amplifies a repair system the body already has. The researchers believe the effect could extend beyond humans to aging cats and dogs as well, since the same HGF pathway operates across species.

Muscle loss isn't limited to older adults, either — prolonged bed rest or inactivity can trigger similar decline at any age, making a broadly applicable fix especially valuable if the early promise holds up.