Southern Medical University: Loading Shinbones Extended Lifespan of Old Mice by 9.4%

Researchers at Southern Medical University in Guangzhou, China, report that repeated gentle pressure on the shinbones of elderly mice improved their strength, coordination and performance on memory tests, New Atlas reports. The treatment also extended median lifespan by an average of 9.4%, or around 80 days. newatlas.comNew Atlasnewatlas.comOpen source ↗ The work was done in mice and published in Cell Metabolism.

The team studied osteocytes, bone cells that detect mechanical forces. These cells use the pressure-sensitive channel PIEZO1 to help bone adapt to physical exertion. newatlas.comNew Atlasnewatlas.comOpen source ↗

PIEZO1 and bone loading

The authors found that PIEZO1 levels declined over time in both mouse and human bone. When the channel was chemically destroyed in osteocytes of adult mice, signs of aging accelerated well beyond the skeleton and affected the brain, liver and muscles. Median lifespan fell by roughly 11% in females and 13% in males. newatlas.comNew Atlasnewatlas.comOpen source ↗

This led the researchers to test whether regular pressure on the skeleton could counter signs of aging. A device rhythmically applied a small load to the shinbones of anaesthetized mice, starting when the animals were 20 months old. newatlas.comNew Atlasnewatlas.comOpen source ↗

Treated mice lived longer and showed better blood sugar regulation and bone structure. Markers of inflammation and senescence were reduced in several organs. The aging immune system moved toward a more youthful state, including changes in the blood-producing tissue of the marrow. newatlas.comNew Atlasnewatlas.comOpen source ↗

PEDF and the limits of the study

Plasma from treated mice, transferred to other old mice, delivered benefits. This suggests that a factor circulating in the blood was responsible. One candidate was pigment epithelium-derived factor (PEDF), a protein with protective effects in several tissues. Bone loading raised its circulating levels, and injections of PEDF reduced several signs of aging and improved cognitive and physical performance in older mice. newatlas.comNew Atlasnewatlas.comOpen source ↗

The study did not test whether bone loading extends human lifespan. Blood PEDF in people drops significantly with age, and the protein protected laboratory-grown human cartilage from experimentally induced damage. newatlas.comNew Atlasnewatlas.comOpen source ↗

The researchers acknowledge that they have not established whether PEDF is essential for the effects of loading. Other proteins, immune changes and signaling pathways could also contribute. A twice-weekly shinbone squeeze, as New Atlas notes, does not reproduce everything that walking, swimming or strength training does for the human body. newatlas.comNew Atlasnewatlas.comOpen source ↗