Your bones affect your appetite—and your metabolism

November 1, 2017, University of Montreal
Credit: CC0 Public Domain

Your skeleton is much more than the structure supporting your muscles and other tissues. It produces hormones, too. And Mathieu Ferron knows a lot about it. The researcher at the Montreal Clinical Research Institute (IRCM) and professor at Université de Montréal's Faculty of Medicine has spent the last decade studying a hormone called osteocalcin. Produced by our bones, osteocalcin affects how we metabolize sugar and fat.

In a recent paper in The Journal of Clinical Investigation, Ferron's team unveiled a new piece of the puzzle that explains how osteocalcin works. The discovery may someday open the door to new ways of preventing type 2 diabetes and obesity.

Bone: An endocrine organ

It has long been known that hormones can affect bones. "Just think about how women are more prone to suffer from osteoporosis when they reach menopause because their estrogen levels drop," said Ferron, director of the IRCM's Integrative and Molecular Physiology Research Unit.

But the idea that bone itself can affect other tissues took root only a few years ago with the discovery of osteocalcin. Thanks to this , produced by bone cells, sugar is metabolized more easily.

"One of osteocalcin's functions is to increase , which in turn reduces glucose levels," Ferron explained. "It can also protect us from obesity by increasing ."

Studies have shown that, for some people, changes in blood concentrations of osteocalcin may even stave off the development of diabetes. These protective properties sparked Ferron's interest in how this hormone actually works.

Hormone scissors

Osteocalcin is produced by osteoblasts, the same cells responsible for making our bones. The hormone builds up in bone, and then, through a series of chemical reactions, is released into the blood. The IRCM team is focusing on this key step.

"When it is first produced in osteoblasts, osteocalcin is in an ," Ferron noted. "What interested us was understanding how osteocalcin becomes active so as to be able to play its role when released into the blood."

The IRCM lab demonstrated that an enzyme, which acts like molecular scissors, is required. Inactive osteocalcin has one more piece than active osteocalcin. The researchers examined in mice the different enzymes present in cells where osteocalcin was produced that could be responsible for snipping off the piece in question.

Ferron's team succeeded in identifying it: it's called furin. Furin causes osteocalcin to become active and the hormone is then released into the blood.

"We demonstrated that when there was no furin in , inactive osteocalcin built up and was still released, but this led to an increase in and a reduction in energy expenditure and insulin production," Ferron said.

Deleting these "scissors" also had an unexpected effect: it reduced the mice's appetite. "We're confident that the absence of furin was the cause," Ferron said.

Indeed, his team demonstrated that osteocalcin itself has no effect on appetite. "Our results suggest the existence of a new hormone that controls food intake," Ferron said.

"In future work, we hope to determine whether furin interacts with another protein involved in appetite regulation."

Explore further: Can our bones protect us against diabetes and obesity?

More information: Omar Al Rifai et al, Proprotein convertase furin regulates osteocalcin and bone endocrine function, Journal of Clinical Investigation (2017). DOI: 10.1172/JCI93437

Related Stories

Can our bones protect us against diabetes and obesity?

March 17, 2015
A team of researchers at the IRCM led by Mathieu Ferron, PhD, in collaboration with researchers at Columbia University, discovered a new function of the skeleton associated with diabetes and obesity. The scientific breakthrough, ...

Bone hormone boosts muscle performance during exercise but declines with age

June 14, 2016
When we exercise, our bones produce a hormone called osteocalcin that increases muscle performance, according to a study publishing June 14 in a Cell Metabolism special issue on aging. Osteocalcin naturally declines in humans ...

Bone-derived hormone reverses age-related memory loss in mice

August 29, 2017
Age-related memory loss may be reversed by boosting blood levels of osteocalcin, a hormone produced by bone cells, according to mouse studies led by Columbia University Medical Center (CUMC) researchers. The research team ...

Bone-derived hormone suppresses appetite in mice

March 8, 2017
A hormone secreted by bone cells can suppress appetite, according to mouse studies conducted by Columbia University Medical Center (CUMC) researchers. The hormone—called lipocalin 2—turns on neurons in the brain that ...

Bone hormone influences brain development and cognition

September 26, 2013
Researchers from Columbia University Medical Center (CUMC) have found that the skeleton, acting through the bone-derived hormone osteocalcin, exerts a powerful influence on prenatal brain development and cognitive functions ...

Recommended for you

Fabric imbued with optical fibers helps fight skin diseases

February 23, 2018
A team of researchers with Texinov Medical Textiles in France has announced that their PHOS-ISTOS system, called the Fluxmedicare, is on track to be made commercially available later this year. The system consists of a piece ...

Low-calorie diet enhances intestinal regeneration after injury

February 22, 2018
Dramatic calorie restriction, diets reduced by 40 percent of a normal calorie total, have long been known to extend health span, the duration of disease-free aging, in animal studies, and even to extend life span in most ...

Artificial intelligence quickly and accurately diagnoses eye diseases and pneumonia

February 22, 2018
Using artificial intelligence and machine learning techniques, researchers at Shiley Eye Institute at UC San Diego Health and University of California San Diego School of Medicine, with colleagues in China, Germany and Texas, ...

Gut microbes protect against sepsis—mouse study

February 22, 2018
Sepsis occurs when the body's response to the spread of bacteria or toxins to the bloodstream damages tissues and organs. The fight against sepsis could get a helping hand from a surprising source: gut bacteria. Researchers ...

Breakthrough could lead to better drugs to tackle diabetes and obesity

February 22, 2018
Breakthrough research at Monash University has shown how different areas of major diabetes and obesity drug targets can be 'activated', guiding future drug development and better treatment of diseases.

Fertility breakthrough: New research could extend egg health with age

February 22, 2018
Women have been told for years that if they don't have children before their mid-30s, they may not be able to. But a new study from Princeton University's Coleen Murphy has identified a drug that extends egg viability in ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.