A new study from the University of Hong Kong has revealed how exercise helps keep bones strong—and how we might mimic this effect in people who cannot move or exercise.
The research, published in the journal Signal Transduction and Targeted Therapy, has identified a special protein in the body that acts like an “exercise sensor.”
This could lead to new drugs that help protect bone health for people who are elderly, bedridden, or living with long-term illnesses.
Osteoporosis is a condition where bones become weak and brittle. It affects millions of people around the world, especially older adults. Weak bones can easily break, leading to pain, disability, and a loss of independence.
According to the World Health Organization, about one in three women and one in five men over 50 will suffer a fracture due to osteoporosis. In Hong Kong, the problem is serious, with 45% of women and 13% of men over 65 affected by this condition.
As people age, their bones naturally lose strength and become more porous. In the bone marrow, there are special cells called mesenchymal stem cells. These cells can develop into either bone or fat. In younger, healthy people, these cells help make new bone. But with age, they tend to turn into fat cells instead.
When too much fat builds up in the bone marrow, there is less space for new bone to grow. This weakens the bones even more, and current treatments often can’t reverse the damage.
To better understand this process, the researchers used mice and human stem cells to explore how bones respond to movement. They discovered a protein called Piezo1 that sits on the surface of stem cells in the bone marrow.
This protein acts like a switch that gets turned on by physical activity. When Piezo1 is activated, it tells the stem cells to build new bone and reduce fat buildup. This helps keep bones strong and healthy.
However, when the Piezo1 protein is missing or not working properly, the cells start creating more fat instead of bone. The study also found that in this case, the body releases certain harmful signals, such as Ccl2 and lipocalin-2, which make the problem worse.
These signals cause more fat to form in the bone and make it harder for new bone to grow. But the good news is that blocking these signals might help reverse the process and improve bone health.
This discovery is very exciting for people who are unable to exercise. Professor Xu Aimin, who led the study, explained that by targeting the Piezo1 pathway, scientists could develop treatments that make the body think it is exercising, even when there is no movement. This could be life-changing for patients who are bedridden, elderly, or recovering from injuries.
Dr. Wang Baile, who co-led the research, said that this finding is especially meaningful for people who are too frail or ill to stay active. The team hopes to create “exercise mimetics”—drugs that copy the effects of exercise by activating the Piezo1 protein. This approach could help maintain bone strength, support mobility, and prevent dangerous fractures.
Professor Eric Honoré, another researcher involved in the study, added that this could go far beyond traditional physical therapy. In the future, people may be able to gain the same benefits as exercise through medicine that targets this new sensor in the body.
The research team is now working on turning this discovery into real-world treatments. Their goal is to help aging adults and people with limited mobility maintain strong bones and a better quality of life.
If you care about bone health, please read studies that plant-based diets can harm your bone health without these nutrients, and this bone problem may strongly increase COVID-19 death risk.
For more health information, please see recent studies that too much of this vitamin may increase your risk of bone fractures, and results showing this type of exercise may protect your bone health, slow down bone aging.
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