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 Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>