Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSD researchers maintain stem cells without contaminated animal feeder layers

29.03.2005


The growth and maintenance of human embryonic stem cells in the absence of contaminated animal products has been demonstrated by University of California, San Diego (UCSD) School of Medicine researchers in the Whittier Institute*, La Jolla, California.

Published in the April 2005 issue of the journal Stem Cells, the study shows that laboratory culture media enriched by a human protein called activin A are capable of maintaining human embryonic stem cells in a continuous undifferentiated state, ready for research. Undifferentiation means the stem cells have not begun the developmental path to become specific human tissue or organs. "Our findings provide a new way to generate human stem cell lines without contamination by animal cells or products," said the study’s senior author, Alberto Hayek, M.D., UCSD professor of pediatrics and director of the Islet Research Laboratory at the Whittier Institute.
Currently, stem cell lines derived from human embryos are grown and nourished in petri dish material called feeder layers that are made with animal connective tissue, primarily mouse and calf. A recent study in Nature Medicine** by UCSD’s Ajit Varki, M.D. showed that human embryonic stem cells grown in this animal-derived tissue become contaminated with a non-human molecule called Neu5Gc. If these stem cells were to be transplanted into people, they would provoke an immune system attack eliminating their therapeutic value.


While several laboratories have attempted to grow stem cells in alternative cultures, problems have remained. In some cases, human feeder layers were developed but this added another measure of complexity to the culture system, Hayek noted. In recent studies in Wisconsin and Massachusetts, new feeder layers were developed, but they did not entirely eliminate the use of animal products. In the Hayek study, the animal-derived feeder layers are completely eliminated. However, the petri dishes themselves are coated with laminin (an animal-derived product), and the UCSD team is continuing studies to determine if contamination occurs from this source.

For a proposed animal-free medium, the UCSD study takes advantage of a previously unidentified soluble factor this is secreted from mouse feeder layers to maintain stem cells’ undifferentiated state and pluripotency, the ability to become all tissue types in the body. The scientists knew that a cocktail of various growth factors and chemicals had previously been shown to modulate cellular growth and differentiation in human pancreatic cells. Human embryonic stem cells cultured for several weeks under these conditions showed no change in cell form and structure. The team then eliminated each factor and pluripotency was assessed. At first, the results were narrowed to three molecules, with activin A, a protein that participates in cellular growth and differentiation, as well as hormone secretion, finally shown in additional testing to maintain the undifferentiated state.

The study’s first author, Gillian M. Beattie, M.S., UCSD Department of Pediatrics and the Whittier Institute, said that "it will be rather simple now to develop a specific defined medium that allows for the maintenance of the human stem cells and enhances research without the problem of contaminating animal cells and their products."

In a summary to their paper, the researchers noted that "the identification of activin A as a key factor in mediating these cellular events will help to unravel the biochemical pathways responsible for ’stemness’. An increased efficiency in the generation and culture of human stem cells for potential clinical applications is timely, given the recent report of 17 newly derived stem cell lines available for non-federal research. The findings here may facilitate the derivation of new human embryonic stem cell lines without the use of animal or human feeder layers."

Sue Pondrom | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Fine organic particles in the atmosphere are more often solid glass beads than liquid oil droplets
21.04.2017 | Max-Planck-Institut für Chemie

nachricht Study overturns seminal research about the developing nervous system
21.04.2017 | University of California - Los Angeles Health Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>