Corporate Banner
Satellite Banner
Stem Cells, Cellular Therapy & Biobanking
Scientific Community
Become a Member | Sign in
Home>News>This Article

Beacons Light Up Stem Cell Transformation

Published: Friday, September 14, 2012
Last Updated: Friday, September 14, 2012
Bookmark and Share
In a new study, Brown University researchers demonstrate a new tool for visually tracking in real-time the transformation of a living population of stem cells into cells of a specific tissue.

The “molecular beacons,” which could advance tissue engineering research, light up when certain genes are expressed and don’t interfere with the development or operation of the stem cells.

A novel set of custom-designed “molecular beacons” allows scientists to monitor gene expression in living populations of stem cells as they turn into a specific tissue in real-time. The technology, which Brown University researchers describe in a new study, provides tissue engineers with a potentially powerful tool to discover what it may take to make stem cells transform into desired tissue cells more often and more quickly. That’s a key goal in improving regenerative medicine treatments.

“We’re not the inventors of molecular beacons but we have used it in a way that hasn’t been done before, which is to do this in long-term culture and watch the same population change in a reliable and harmless way,” said graduate student Hetal Desai, lead author of the paper published online Sept. 5, 2012, in the journal Tissue Engineering Part A.

In their research, Desai and corresponding author Eric Darling, assistant professor of biology in the Department of Molecular Pharmacology, Physiology, and Biotechnology, designed their beacons to fluoresce when they bind to mRNA from three specific genes in fat-derived stem cells that are expressed only when the stem cells are transforming into bone cells.

Throughout 21 days of their development, the cells in the experiments remained alive and unfettered, Desai said, except that some populations received a chemical inducement toward becoming bone and others did not. Over those three weeks, the team watched the populations for the fluorescence of the beacons to see how many stem cells within each population were becoming bone and the timing of each gene expression milestone.

The beacons’ fluorescence made it easy to see a distinct pattern in that timing. Expression of the gene ALPL peaked first in more than 90 percent of induced stem cells on day four, followed by about 85 percent expressing the gene COL1A1 on day 14. The last few days of the experiments saw an unmistakably sharp rise in expression of the gene BGLAP in more than 80 percent of the induced stem cells.

Each successive episode of gene expression ramped up from zero to the peak more quickly, the researchers noted, leading to a new hypothesis that the pace of the stem cell transformation, or “differentiation” in stem cell parlance, may become more synchronized in a population over time.

“If you could find a way to get them on this track earlier, you could get the differentiation faster,” Darling said.

Meanwhile the stem cell populations that were not induced with bone-promoting chemicals, showed virtually no beacon fluorescence or expression of the genes, indicating that the beacons were truly indicators of steps along the transformation from stem cell to bone.

Beacons don’t affect cells

Desai said the team took extra care to design beacons that would not alter the cells’ development or functioning in any way. While the beacons do bind to messenger RNA produced in gene expression, for example, they do not require adding any genes to the stem cells’ DNA, or expressing any special proteins, as many other fluorescence techniques do.

The team performed several experiments using the beacons in conventionally developing bone cells to make sure that they developed normally even as the beacons were in operation. While some scientists design RNA-based probes to purposely interfere with gene expression, this team had the opposite intent.

“You know that [.38 Special] song ‘Hold on Loosely but Don’t Let Go?’” Desai said. “That’s sort of the theme song for this. There’s a set of rules for interference RNA, and we essentially did the opposite of what those rules said you should do.”

Toward quicker healing

Now that the beacons’ performance in indicating milestones of stem cell differentiation has been demonstrated, Darling said, the technology can be applied to studying the process in a wide variety of cells and under a variety of other experimental conditions.

In the case of tissue engineering, he said, the beacons can aid experiments seeking to determine what conditions (inducing chemicals or otherwise) are most effective in converting the most stem cells to desired tissues most quickly. They could help tissue engineers learn the best timing for adding an inducing chemical. They might also provide a way for tissue engineers to identify and harvest only those cells that are converting to the desired tissue.

“They are becoming bone cells and if you enrich for them and you get rid of all the ones that aren’t becoming bone cells, it stands to reason that you will have a better product at the end,” Darling said.
More broadly, Darling added, molecular beacons are proving useful in a wide variety of gene expression studies.

“The reason we are looking at this technique is that we wanted something we could use on any cell, look at any gene and not affect that cell while we are looking at it,” Darling said. “If this is acting as we believe it is, we can really look at any gene that we want. It seems like a very versatile tool.”

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Scientific News
CRI Identifies Emergency Blood-formation Response
Researchers report that when tissue damage occurs, an emergency blood-formation system activates.
New Way to Force Stem Cells to Become Bone Cells
Potential therapies based on this discovery could help people heal bone injuries or set hardware, such as replacement knees and hips.
Dead Bacteria to Kill Colorectal Cancer
Scientists from Nanyang Technological University (NTU Singapore) have successfully used dead bacteria to kill colorectal cancer cells.
Promise of Newborn Stem Cells to Revolutionize Clinical Practice
In this article Shweta Sharma, PhD, discusses the potential of an Umbilical Cord Blood bank as an untapped source of samples for research and clinical trials.
The Life Story of Stem Cells
A model analyses the development of stem cell numbers in the human body.
Novel Stem Cell Line Avoids Risk of Introducing Transplanted Tumors
Progenitor cells might eventually be used to repair or rebuild damaged or destroyed organs.
Advancing Genome Editing of Blood Stem Cells
Genome editing techniques for blood stem cells just got better, thanks to a team of researchers at USC and Sangamo BioSciences.
Molecule Proves Key to Brain Repair After Stroke
Scientists found that a molecule known as growth and differentiation factor 10 (GDF10) plays a key role in repair mechanisms following stroke.
Towards Patient-Specific Drug Screening
A new breakthrough by the 3D stem cell printing team at Heriot-Watt could pave the way to individually tailored drug testing regimes, both reducing the need for animal testing and ensuring that patients receive drugs which are most effective for their individual needs.
Gene-Edited Immune Cells Treat ‘Incurable’ Leukaemia
A new treatment that uses ‘molecular scissors’ to edit genes and create designer immune cells programmed to hunt out and kill drug resistant leukaemia has been used at Great Ormond Street Hospital (GOSH).
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos