Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers now on road to isolating skin stem cells

22.09.2003


Researchers at the San Francisco VA Medical Center (SFVAMC) have taken the first major step toward isolating adult stem cells from mouse skin, having developed a test that confirms the presence and number of stem cells in a given amount of tissue. Until now, such a technique has only existed for isolating adult stem cells found in blood.



"This assay has opened up a whole new avenue of research," said Ruby Ghadially, MD, SFVAMC staff physician and UCSF associate professor of dermatology. "If you can determine how many stem cells you have, then you can identify distinguishing characteristics that will allow you to isolate the cells. We could then potentially use these cells as effective carrier cells for gene therapy and, someday, use them to produce new stem cells for treating burns and wounds in the skin," Ghadially said.

The study was published online September 17 in the Proceedings of the National Academy of Sciences’s online early edition, and will appear in the print version of the journal September 30.


Stem cells are the body’s unspecialized cells, which give rise to the specialized cell types that make up an organism. Embryonic stem cells emerge in the first days of an embryo’s development, and have the potential to differentiate, or specialize, into each of the 200 types of tissue in the body. Adult stem cells are unspecialized cells found in specialized tissues throughout the body, including bone marrow, skin and the pancreas, among others. They can reproduce themselves as well as give rise to all the cell types of the tissue in which they are found. Scientists are working to take advantage of the natural properties of stem cells in order to develop ways of repairing or replacing the cells of damaged tissues and organs.

Knowing the number of stem cells allows researchers to look for cell-surface molecules, or markers, that distinguish stem cells from specialized cells. This allows researchers to isolate stem cells from specialized cells and investigate ways of taking advantage of their ability to make new specialized cells. For example, stem cells isolated from the blood are now being used to treat cancer patients whose blood cells are damaged by radiation treatment or chemotherapy. Stem cells taken from either the patient before treatment or from a donor are transplanted into the patient following treatment where they make new blood cells.

Using the new assay for skin stem cells, the researchers found that the bottom layer of skin, called the basal epidermis, had the same number of stem cells as found in bone marrow: about one in every 10,000 cells. The assay relies on the same concepts as those used to quantify stem cells in blood. Researchers placed skin cells from two donor mice onto a patch of denuded skin of a third mouse. The cells from one donor were labeled with green fluorescent protein (GFP). The differentiated cells that make up the layers of the skin died off as expected, while stem cells, which are permanent, produced new differentiated cells that replaced the ones that died. So, to confirm the presence of stem cells in their test mice, researchers looked for those cells that still glowed green after a month.

To estimate the number of cells in basal epidermis, researchers kept the number of cells of the non-labeled donor constant over a number of host mice. But, they varied the number of the GFP cells to see how small a sample they could add before they saw no green stem cells after a month’s time. This process, called limiting dilution, gave them the ratio of stem cells to differentiated cells in their GFP samples.

According to Ghadially, research using stem cells from the blood is 20 years ahead of other stem cell research, largely because researchers have a similar assay they use to quantify the number of stem cells in a given sample. "We know a lot about stem cells in the blood and that’s because we can get our hands on them. Now we can determine which markers distinguish stem cells from differentiated skin cells, which will eventually allow us to isolate skin stem cells," Ghadially said.

The eventual isolation of skin stem cells, Ghadially said, promises to allow the treatment of wounds, including burns, through transplantation of stem cells directly onto the damaged area where new skin will grow. It may take decades, but Ghadially predicts researchers also will be able to prompt skin stem cells to produce more stem cells in the same way researchers have been able to do with stem cells taken from the blood. Also, isolating epidermal stem cells will allow skin researchers to better understand the process by which skin cells differentiate and, since skin cancer likely originates in stem cells, better understand--and maybe someday better treat--skin cancer.

Additional authors include Tracy E. Schneider, BS, Chantal Barland, MD, and April M. Alex, MS, of the UCSF Department of Dermatology; Ying Lu, PhD, statistician and James E. Cleaver, PhD, researcher of the UCSF Comprehensive Cancer Center; H. Jeffrey Lawrence, MD, SFVAMC staff physician and UCSF professor of medicine; and Maria L. Mancianti, MD, of the Department of Pathology, Alta Bates Medical Center, Berkeley, CA.



This research was supported by two grants to Ghadially from the National Institutes of Health and a Department of Veterans Affairs Merit Review Program Award.

Camille Mojica Rey | EurekAlert!
Further information:
http://www.ucsf.edu/

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>