Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stem cells grown in lab mirror normal developmental steps

22.06.2005


Johns Hopkins scientists have developed a way to study the earliest steps of human blood development using human embryonic stem cells grown in a lab dish instead of the embryos themselves.



The process avoids some of the ethical and technical obstacles involved in such research, according to the Johns Hopkins investigators.

The Johns Hopkins researchers’ system involves the study of existing embryonic stem cell lines derived from in vitro fertilization methods, and so doesn’t require generation of embryos through cloning, a technique recently reported by South Korean scientists.


In their report on the work in the June issue of the journal Blood, the Johns Hopkins team demonstrated a clear similarity between how human embryonic stem cells specialize into blood cells and how blood cells develop in human embryos.

"Our findings provide an unparalleled opportunity to study the basic questions of human development, like ’Where does blood come from?’" says Elias Zambidis, M.D., Ph.D., first author on the paper and an assistant professor of pediatrics and oncology in the Johns Hopkins School of Medicine.

Knowing the steps by which stem cells develop into blood cells are likely to help medical researchers figure out how to treat cancers of the blood, such as leukemia and lymphoma, Zambidis notes.

"More and more we’re learning that the genes that turn on in the embryo to make blood stem cells are the same genes that go wrong in cancer," he says. "So if we understand what the important genes are and how they work, we might be able to develop and to target new cancer therapies more effectively."

Historically, scientists have worked on mouse and zebrafish models of embryological blood cell development, but ethical and technical barriers have stood in the way of an in-depth study of blood formation in human embryos. In the new work, Hopkins scientists and colleagues from the University of Pittsburgh School of Medicine used laboratory-grown dishes of human stem cells, in clumps called human embryoid bodies, and observed three distinct steps taken by stem cells on their way to becoming blood cells.

Without any chemical manipulation or stimulation, the clusters of human stem cells first became colonies of cells that can produce endothelium, or the tissue that makes up the circulatory system. These colonies can then also form the precursors of blood cells, in a structure similar to the yolk sac of human embryos. Finally, some of the cells in the colonies form blood cells similar to those found in the liver and bone marrow of a developing fetus, making it simple for the researchers to pick out the blood cells for further investigation. "We were quite surprised to find that these steps proceeded spontaneously, without the need for stimulation by growth factors or other chemicals," says Zambidis. "It’s likely that the same method of picking out certain kinds of cells could be used to study processes other than blood cell development."

Most importantly, Zambidis says, the stages of blood cell development he and his team found in the stem cell lines correlate with what is already known about early stages of human blood cell development in embryos in the womb. "We’ve captured these phases of stem cell specialization, or differentiation, in a dish," says Zambidis. "Now we can study these phases and hopefully help solve the Rubik’s Cube of how human development works."

Because embryonic stem cells are capable of becoming virtually every type of cell in the human body, understanding how they do so might provide the chance to harness that process to make a limitless supply of specific cells for therapeutic purposes. For instance, stem cells directed down the path of blood cell development might be useful to help treat leukemias or other blood disorders.

Zambidis and colleagues are currently using their model to study the next stage in blood cell development, which in a growing embryo involves blood cell precursors moving from the yolk sac into the liver, bone marrow and thymus. Zambidis says that if blood stem cells are to be used for therapeutic purposes, they would likely come from this next stage of development.

Katherine Unger | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

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

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>