Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UNC researchers find new way to force stem cells to become bone cells

17.11.2015

Potential therapies based on this discovery could help people heal bone injuries or set hardware, such as replacement knees and hips

Imagine you have a bone fracture or a hip replacement, and you need bone to form, but you heal slowly - a common fact of life for older people. Instead of forming bone, you could form fat. Researchers at the University of North Carolina School of Medicine may have found a way to tip the scale in favor of bone formation. They used cytochalasin D, a naturally occurring substance found in mold, as a proxy to alter gene expression in the nuclei of mesenchymal stem cells to force them to become osteoblasts (bone cells).


Left: Green actin fibers create architecture of the cell. Right: With cytochalasin D added, actin fibers disband and reform in the nuclei.

Credit: UNC School of Medicine

By treating stem cells - which can become fat or bone cells - with cytochalasin D- the result was clear: the stem cells became bone cells. Further, injecting a small amount of cytochalasin D into the bone marrow space of mice caused bone to form. This research, published in the journal Stem Cells, details how the scientists altered the stem cells and triggered bone growth.

"And the bone forms quickly," said Janet Rubin, MD, senior author of the paper and professor of medicine at the UNC School of Medicine. "The data and images are so clear; you don't have to be a bone biologist to see what cytochalasin D does in one week in a mouse."

Rubin added, "This was not what we expected. This was not what we were trying to do in the lab. But what we've found could become an amazing way to jump-start local bone formation. However, this will not address osteoporosis, which involves bone loss throughout the skeleton."

At the center of the discovery is a protein called actin, which forms fibers that span the cytoplasm of cells to create the cell's cytoskeleton. Osteoblasts have more cytoskeleton than do adipocytes (fat cells). Buer Sen, MD, first author of the Stem Cells paper and research associate in Rubin's lab, used cytochalasin D to break up the actin cytoskeleton. In theory - and according to the literature - this should have destroyed the cell's ability to become bone cells. The cells, in turn, should have been more likely to turn into adipocytes. Instead, Sen found that actin was trafficked into the nuclei of the stem cells, where it had the surprising effect of inducing the cells to become osteoblasts.

"My first reaction was, 'No way, Buer,'" Rubin said. "'This must be wrong. It goes against everything in the literature.' But he said, 'I've rerun the experiments. This is what happens.'" Rubin's team expanded the experiments while exploring the role of actin. They found that when actin enters and stays in the nucleus, it enhances gene expression in a way that causes the cell to become an osteoblast.

"Amazingly, we found that the actin forms an architecture inside the nucleus and turns on the bone-making genetic program," Rubin said. "If we destroy the cytoskeleton but do not allow the actin to enter the nucleus, the little bits of actin just sit in the cytoplasm, and the stem cells do not become bone cells."

Rubin's team then turned to a mouse model. Using live mice, they showed that cytochalasin D induced bone formation in mice.

Bone formation in mice isn't very different from that in humans, so this research might be translatable. And while cytochalasin D might not be the actual agent scientists use to trigger bone formation in the clinic, Rubin's study shows that triggering actin transport into the nuclei of cells may be a good way to force mesenchymal stem cells to become bone cells.

###

Rubin, the vice chair for research at the UNC School of Medicine, holds join appointments in pediatrics and pharmacology, and is an adjunct professor of bioengineering.

This work was funded by the National Institutes of Health.

Mark Derewicz | EurekAlert!

More articles from Life Sciences:

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

nachricht Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

Scientists create innovative new 'green' concrete using graphene

24.04.2018 | Materials Sciences

BAM@Hannover Messe: innovative 3D printing method for space flight

24.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>