Frog provides insight into making specialised cells from stem cells

August 27, 2006

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

Explore further: Coral study reveals secrets of evolution

Related Stories

Coral study reveals secrets of evolution

October 5, 2016

Corals first appeared on earth nearly half a billion years ago during the Cambrian Period of the Paleozoic Era. The ancient Greek philosopher Aristotle categorized corals as zoophyta, or "plant-animals", due to their plant-like ...

Genetic choreography of the developing human embryo

September 9, 2016

Years ago, when I was teaching at a state university, I had the privilege to show real human embryos and fetuses to my genetics classes. An obstetrician back in the 1950s had saved them after patients had miscarried, with ...

Stem cell discovery challenges dogma on how fetus develops

October 14, 2014

A Mount Sinai-led research team has discovered a new kind of stem cell that can become either a liver cell or a cell that lines liver blood vessels, according to a study published today in the journal Stem Cell Reports. The ...

Recommended for you

Hubble catches a transformation in the Virgo constellation

December 9, 2016

The constellation of Virgo (The Virgin) is especially rich in galaxies, due in part to the presence of a massive and gravitationally-bound collection of over 1300 galaxies called the Virgo Cluster. One particular member of ...

Hydrogen from sunlight—but as a dark reaction

December 9, 2016

The storage of photogenerated electric energy and its release on demand are still among the main obstacles in artificial photosynthesis. One of the most promising, recently identified photocatalytic new materials is inexpensive ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.