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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>