Implanted muscle tissue mimics exercise in aged mice
Scientists have developed a technique in which a small piece of muscle tissue is implanted under the skin. That tissue contracts automatically and sends the same signals into the body as physical exercise. In aged and obese mice, it improved overall metabolism.
Muscles are not passive tissue. With every contraction they release substances that influence other organs. That is one of the reasons why exercise has such broad health benefits. But for people who cannot exercise because of illness, advanced age, or limited mobility, those substances are hard to access. Researchers looked for a way to generate that effect artificially.
The researchers, whose work was published in Nature Aging, developed a method in which differentiated muscle tissue (tissue that has already fully matured into muscle) is implanted in the space beneath the skin. The distinctive feature is that this tissue contracts automatically, without any movement from the recipient. Those contractions trigger the release of signalling proteins that normally become available during exercise.
Less fat mass, better metabolism
In aged and obese mice, the implantation led to preservation of lean muscle mass and improved whole-body metabolism. These are effects that normally require regular physical activity. The technique is referred to in the article as a ‘myograft’ (an implanted piece of muscle). The concept is not new, but the automatically contracting variant that releases genuine muscle signals is.
Still far from clinical application
This is mouse research. The method works in rodents, but whether it would be feasible, safe, and effective in humans is unknown. Many questions remain about the long-term behaviour of such an implant, the body’s immunological response, and the scale at which sufficient signalling proteins could be produced. The concept is nonetheless interesting for longevity science, because it attempts to bridge the benefits of exercise and people who cannot exercise. That is a relevant problem in ageing.
Terms to search for yourself: muscle secretome myokines aging, muscle graft metabolic health, differentiated muscle tissue transplantation