Frog provides insight into making specialised cells from stem cells

The African clawed frog could help stem cell scientists in obtaining insulin-releasing cells of the pancreas from stem cells, new research published in the latest issue of the journal Development suggests.

Scientists at the Institute for Stem Cell Research, of the University of Edinburgh, have shown that the protein Wnt (pronounced Wint) is crucial in setting up the region of the embryo that will form the pancreas and the liver. The findings open up new avenues for modelling diseases such as diabetes, testing the effects of drugs and, ultimately, developing new transplantation therapies.

The lining of the respiratory and gastrointestinal tracts, the pancreas, the liver, the thymus and the thyroid all have their origin in a structure of the early embryo called the anterior endoderm. Josh Brickman and his team have shown that, in the African clawed frog, the anterior endoderm forms through a cascade of activities of different molecules, leading, ultimately, to the increased activity of a protein called Wnt.

They then used mouse embryonic stem cells to demonstrate that the same cascade exists in mammals and to suggest that this activity of Wnt might be exploited to contribute to current efforts to direct embryonic stem cells to become pure anterior endoderm cells. This would be the first step in obtaining, for example, liver cells and insulin-producing beta cells of the pancreas, in the laboratory.

The scientists also showed that the formation of the anterior endoderm involves switching off a gene for another protein, called Nodal. Based on these findings, the team is already working on extending their results into embryonic stem cells. They are using the Wnt protein in mouse embryonic stem cells to try to produce a pure population of cells which lacks Nodal protein. According to Josh Brickman, “We believe that our findings in frog embryos tell us that these cells would be real anterior endoderm, which can potentially be used to make both liver and pancreas.”

Stem cell scientists are agreed that the best approach in obtaining specialised cell types from embryonic stem cells is to take into account the origin of those cells in the embryo, and the biological processes that govern their appearance. The molecular mechanisms leading to endoderm formation in mammals are not well understood and are more difficult to dissect than in frog embryos, which is, once again, proving to be a valuable ally for researchers.

Source: Institute for Stem Cell Research

Related stories:

Scientists uncover the key to controlling how stem cells develop
(PhysOrg.com) -- The results of a new study involving a McMaster University researcher provide insight into how scientists might control human embryonic stem cell differentiation.
Scientists identify role of tiny RNAs in controlling stem cell fate
Researchers at the Gladstone Institute of Cardiovascular Disease (GICD) and the University of California, San Francisco have identified for the first time how tiny genetic factors called microRNAs may influence the differentiation of pluripotent embryonic stem (ES) cells into cardiac muscle.
From frogs to humans, brains form the same way
It’s a critical juncture in an embryo’s development: the moment that a brain and nervous system begin to form from a mass of unspecialized cells. Scientists had believed that mammals and amphibians, distinctly different animals, have distinctly different developmental patterns when it comes to the nervous system. But new research suggests that their processes of neural development are actually quite similar.
Lipid plays big role in embryonic development
A little-known lipid plays a big role in helping us grow from a hollow sphere of stem cells into human beings, researchers have found.
Scientists discover new, readily available source of stem cells
Scientists have discovered a new source of stems cells and have used them to create muscle, bone, fat, blood vessel, nerve and liver cells in the laboratory. The first report showing the isolation of broad potential stem cells from the amniotic fluid that surrounds developing embryos was published today in Nature Biotechnology.
Human stem cells can contribute to a developing mouse embryo, despite evolutionary differences
Using a newly derived line of human embryonic stem cells, Rockefeller University researchers have coaxed human cells to grow in mouse tissue.
Mayo researchers explore issues related to multiple myeloma treatment
Multiple myeloma (MM) is a cancer of plasma cells that affects approximately 3 in 100,000 people each year. Although there is no cure for this disease, researchers have developed treatments that help relieve pain, control complications, and slow the progress of MM in many patients. Unfortunately, some of the most effective therapies also have toxic side effects that can pose serious health risks and reduce quality of life. In the October issue of Mayo Clinic Proceedings, two articles authored by Mayo researchers address the issue of how to balance the risks and benefits associated with MM treatments.
Scientists identify a molecule that coordinates the movement of cells
Even cells commute. To get from their birthplace to their work site, they sequentially attach to and detach from an elaborate track of exceptionally strong proteins known as the extracellular matrix. Now, in research to appear in the October 3 issue of Cell, scientists at the Howard Hughes Medical Institute and Rockefeller University show that a molecule, called ACF7, helps regulate and power this movement from the inside - findings that could have implications for understanding how cancer cells metastasize.

News discussion:

General Science news