An enzyme found in fatty tissue in the center of bones helps control the production of new bone and fat cells, according to a study published today in mice in eLife.
The findings may help scientists better understand how the body is maintained fat stores and bone production in response to changing conditions, such as during aging. They may also suggest new approaches to treating conditions that cause bone loss in older adults.
Fat cells, including those found in the bone marrow, are increasingly recognized as an important part of the body that helps regulate body weight, insulin sensitivity, and bone mass. Bone marrow fatty tissue expands as people age or when they take certain diabetes medications and during prolonged fasting.
“This expansion of bone marrow fat is strongly associated with bone loss in mice and humans,” explains lead author Nicole Aaron, Ph.D., a student at the College of Vagelos Physicians and Surgeons of the Columbia University, New York, USA. “But it is still not well understood how these changes occur.”
Aaron and his colleagues conducted a series of experiments to explore these processes further. They fed the mice on a calorie-restricted diet and found that this increased fat in the bone marrow and increased the production of an enzyme called adipsin. Adipsin levels were also high in mice treated with a diabetes medicine called rosiglitazone, which increases bone marrow fat and decreases bone mass. Aging also brought about similar changes in animals.
The team then conducted similar experiments on mice that were genetically engineered to have no adipsin. They found that the animals were resistant to these changes and had less bone marrow fat and stronger bones. Specifically, these experiments showed that it appears to cause adipsin stem cells in the bone marrow to become fat cells instead of bone cells.
“Similarly, the results of our human studies also revealed that bone marrow fat expansion with fasting was associated with a marked increase in adipsin and evidence of bone rupture, ”says author Clifford Rosen, director of clinical and translational research of Maine Medical Center, Portland, Maine, USA. ” the findings may help explain the link between the expansion of bone marrow fatty tissue and bone strength, especially during aging. “
Adipsin-blocking drugs are currently being developed to treat people with some form of age-related vision loss. The current study also suggests that these drugs may help increase bone mass in older people with diseases such as osteoporosis that they cause progressively. os loss.
“There is the potential to reuse these existing treatments to treat and prevent age-related skeletal disorders,” concludes lead author Li Qiang, Ph.D., assistant professor of pathology and cell biology at the College. of Vagelos Physicians and Surgeons at Columbia University. . “These treatments could also be aimed at people who are developing bone loss as a result of eating disorders, such as anorexia, or aging. ”
Nicole Aaron et al, Adipsin promotes bone marrow adiposity in priming mesenchymal stem cells, eLife (2021). DOI: 10.7554 / eLife.69209
Citation: How a Bone Marrow Fat Hormone Controls Bone Cell Metabolism and Development (2021, June 22) Retrieved June 23, 2021 at https://medicalxpress.com/news/2021 -06-bone-marrow-fat-hormone-metabolism.html
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