Bones have a hidden role in muscle, appetite and health.
Long, strong, silent bones, not as quiet as before. They had a lot to say. The rest of the body seems to be listening.
Scientists know that bones are not just rigid scaffolds to support and protect soft tissue. The bones themselves are kaleidoscopic. Day by day, they are destroying old batteries and creating new ones. This constant turnover is known as remodeling, strong bones and good health.
Hormones are naturally secreted chemicals. They act like a remote messenger in the body, directing some organizations to take on some tasks and at the right time. Several hormones, for example, are the key to helping reshape bones. Emerging data now suggests that bones don’t just tell other bones when to do things. Mouse studies have shown that bone hormones communicate with a large number of organs and tissues, including the brain, kidneys and pancreas.
“The relationship between the bone and the brain and all the other organs is very close,” Beate Lanske said. She was a bone and mineral researcher at the harvard college of stomatology in Boston, Massachusetts, and was once considered a “dead organ,” she noted. No longer. The chemical signals they voluntarily release now suggest that bones may actually resemble glands that release hormones.
Clifford Rosen is an endocrinologist at the scarboro Maine medical center (En- doh-krin-oh-gizt). He studies how bone hormones affect health and disease. “The bone has to have some fine-tuning mechanism,” he said. He added that it must be “keeping the whole body in sync with what is happening at the bone level”.
Bones require a lot of energy because they constantly reinvent themselves. The cells called osteoblasts produce new bone. Others, called osteoclasts, break old bones. So it makes sense that the bones “have something to do with the fuel sources necessary for bone formation,” Rosen says. Osteoblasts and osteoclasts can use this hormone.
He points out that a bone – brain link has recently been demonstrated in mice. The bone was produced by lipocalin 2 (LCN2) bacterial infection. But now a study shows that LCN2 can also control hunger.
After the meal, the bone formation cells in the mice absorbed the nutrients and released LCN2 into the blood. This hormone is now spreading to the brain. And it’s there in the gl onto the nerve cells that control hunger. They tell the brain to stop eating, explains Stavroula Kousteni. Physiologist, she works at Columbia University medical center in New York.
She and her colleagues reported the new findings on March 16 in the journal nature.
The researchers believe that most fat cells are LCN2. But in mice, bones produce 10 times as much hormone as fat cells. After the meal, their bones extracted enough LCN2 to raise the level of hormones in the blood, increasing them by three times before eating. Kousteni concludes that appetite control is “a new role for the bones”.
At least three other types of bone hormones also talk to organs other than bone. These hormones are osteocalcin, scleroprotein and fibroblast growth factor 23. Scientists are just beginning to eavesdrop on conversations with other groups. This snooping suggests that bone chatter can play a role in controlling how the body manages sugar, energy and fat.
Ten years ago, scientists began to look for information about the release of chemicals from bones. Gerard Karsenty is a geneticist at Columbia University medical center. He found that there are many links between osteocalcin and metabolism, which is how the body USES food to promote its activities. He reported in 2007 that osteocalcin helps keep blood sugar levels healthy.
Osteocalcin circulates in the blood. There, it collects calcium and other minerals needed for bones. At least in mice, when the hormone reaches the pancreas, it tells cells to increase the production of another hormone, insulin. This is the hormone that the body USES to move sugar out of the blood and into the cell, which promotes activity.
The hormone, which promotes insulin secretion, also tells fat cells to release hormones and increase the body’s sensitivity to insulin. Diabetes is a serious disease with either too little or too little insulin. If osteocalcin ACTS like a mouse in humans, Karsenty says it could be a potential drug for treating diabetes or obesity.
“Their data is pretty convincing,” says Sundeep Khosla. He is a bone biologist at the Mayo clinic in rochester, minn. “but the human data are not certain,” he added. He points out that many things affect how the body regulates blood sugar. It is difficult to show whether osteocalcin is a major participant in people.
Mouse data also showed that osteocalcin may play a role in how the body USES food and energy sources. After injecting the hormone, mice could run to younger mice. Karsenty and his colleagues reported in Cell Metabolism last year that mice that did not receive osteocalcin had only run about half. When the hormone increases endurance, it helps the muscles absorb more nutrients. The muscles react by telling the bones to make more osteocalcin.
Karsenty’s team found that the effect seemed to be happening to people. For example, the blood level of osteocalcin increases during exercise, they point out.