Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain development - the pivotal role of the stem cell environment

04.02.2014
Max Planck researchers explain why iodine deficiency during pregnancy may have disastrous consequences

Higher mammals, such as humans, have markedly larger brains than other mammals. Scientists from the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden recently discovered a new mechanism governing brain stem cell proliferation.


Hirn-Stammzellen (rot) in der embryonalen Großhirnrinde der Maus (Zellkerne: blau).

© MPI f. molekulare Zellbiologie und Genetik, Dresden/ D. Stenzel

It serves to boost the production of neurons during development, thus causing the enlargement of the cerebral cortex – the part of the brain that enables us humans to speak, think and dream. The surprising discovery made by the Dresden-based researchers: two components in the stem cell environment – the extracellular matrix and thyroid hormones – work together with a protein molecule found on the stem cell surface, a so-called integrin.

This likely explains why iodine deficiency in pregnant women has disastrous consequences for the unborn child, affecting its brain development adversely – without iodine, no thyroid hormones are produced. “Our study highlights this relationship and provides a potential explanation for the condition neurologists refer to as cretinism”, says Wieland Huttner, Director at the Max Planck Institute in Dresden. This neurological disorder severely impairs the mental abilities of a person.

In the course of evolution, certain mammals, notably humans, have developed larger brains than others, and therefore more advanced cognitive abilities. Mice, for example, have brains that are around a thousand times smaller than the human one. In their study, which was conducted in cooperation with the Fritz Lipmann Institute in Jena, the researchers in Dresden wanted to identify factors that determine brain development, and understand how larger brains have evolved.

A cosy bed for brain stem cells

Brain neurons are generated from stem cells called basal progenitors that are able to proliferate in humans, but not in mice. In humans, basal progenitors are surrounded by a special environment, a so-called extracellular matrix (ECM), which is produced by the progenitors themselves. Like a cosy bed, it accommodates the proliferating cells. Mice lack such ECM, which means that they generate fewer neurons and have a smaller brain.

The scientists therefore conducted tests to see whether in mice, basal progenitors start to proliferate if a comparable cell environment is simulated. The result: “We simulated an extracellular matrix for the brain stem cells using a stimulating antibody. This antibody activates an integrin on the cell surface of basal progenitors and thus stimulates their proliferation”, explains Denise Stenzel, who headed the experiments.

Because a requirement of thyroid hormones for proper brain development was previously known, the researchers blocked the production of these hormones in pregnant rats to see if their absence would inhibit basal progenitor proliferation in the embryos. Indeed, fewer progenitors and, consequently, neurons were produced, likely explaining the abnormal brain development in the absence of thyroid hormones. When the action of these hormones on the integrin was blocked, the ECM-simulating antibody alone was no longer able to induce basal progenitor proliferation.

A combination of ECM and thyroid hormones thus appears necessary for basal progenitors to proliferate and produce enough neurons for brain development. Human brain stem cells produce the suitable environment naturally. “That is probably how, in the course of evolution, we humans developed larger brains”, says Wieland Huttner, summing up the study. The research produced another important finding: “We were able to explain the role of iodine in embryonic brain development at the cellular level”, says Denise Stenzel. Iodine is essential for the production of thyroid hormones, and an iodine deficiency in pregnant women is known to have adverse effects on the brain development of the unborn child.

Contact
Prof. Dr. Wieland B. Huttner
Max Planck Institute of Molecular Cell Biology and Genetics, Dresden
Phone: +49 351 210-1500
Fax: +49 351 210-1600
Email: huttner@mpi-cbg.de
Denise Stenzel
Max Planck Institute of Molecular Cell Biology and Genetics, Dresden
Phone: +49 35 1210-2461
Email: stenzel@mpi-cbg.de
Original publication
Stenzel, Denise; Wilsch-Bräuninger, Michaela; Wong, Fong Kuan; Heuer, Heike; Huttner, Wieland B.

Integrin αvβ3 and thyroid hormones promote expansion of progenitors in embryonic neocortex

Development (2014) doi: 10.1242/dev.101907

Prof. Dr. Wieland B. Huttner | Max-Planck-Institute
Further information:
http://www.mpg.de/7884685/stem-cells-brain-development

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>