A new method could push research into developmental brain disorders an important step forward. This is shown by a recent study at the University of Bonn in which the researchers investigated the development of a rare congenital brain defect. To do so, they converted skin cells from patients into so called induced pluripotent stem cells. From these ‘jack-of-all-trades’ cells, they generated brain organoids – small three-dimensional tissues which resemble the structure and organization of the developing human brain. The work has now been published in the journal Cell Reports.
Investigations into human brain development using human cells in the culture dish have so far been very limited: the cells in the dish grow flat, so they do not display any three-dimensional structure. Model organisms are available as an alternative, such as mice. The human brain has, however, a much more complex structure. Developmental disorders of the human brain can thus only be resembled to a limited degree in the animal model.
Scientists at the Institute of Reconstructive Neurobiology at the University of Bonn applied a recent development in stem cell research to tackle this limitation: they grew three-dimensional organoids in the cell culture dish, the structure of which is incredibly similar to that of the human brain.
These “mini brains” offer insight into the processes with which individual nerve cells organize themselves into our highly complex tissues. “The method thus opens up completely new opportunities for investigating disorders in the architecture of the developing human brain,” explains Dr. Julia Ladewig, who leads a working group on brain development.
Rare brain deformity investigated
In their work, the scientists investigated the Miller-Dieker syndrome. This hereditary disorder is attributed to a chromosome defect. As a consequence, patients present malformations of important parts of their brain. “In patients, the surface of the brain is hardly grooved but instead more or less smooth,” explains Vira Iefremova, PhD student and lead author of the study. What causes these changes has so far only been known in part.
The researchers produced induced pluripotent stem cells from skin cells from Miller-Dieker patients, from which they then grew brain organoids. In organoids, the brain cells organize themselves – very similar to the process in the brain of an embryo: the stem cells divide; a proportion of the daughter cells develops into nerve cells; these move to wherever they are needed. These processes resemble a complicated orchestral piece in which the genetic material waves the baton.
In Miller-Dieker patients, this process is fundamentally disrupted. “We were able to show that the stem cells divide differently in these patients,” explains associate professor Dr. Philipp Koch, who led the study together with Dr. Julia Ladewig. “In healthy people, the stem cells initially extensively multiply and form organized, densely packed layers. Only a small proportion of them becomes differentiated and develops into nerve cells.”
Certain proteins are responsible for the dense and even packing of the stem cells. The formation of these molecules is disrupted in Miller-Dieker patients. The stem cells are thus not so tightly packed and, at the same time, do not have such a regular arrangement. This poor organization leads, among other things, to the stem cells becoming differentiated at an earlier stage. “The change in the three-dimensional tissue structure thus causes altered division behavior,” says Ladewig. “This connection cannot be identified in animals or in two-dimensional cell culture models.”
The scientist emphasizes that no new treatment options are in sight as a result of this. “We are undertaking fundamental research here. Nevertheless, our results show that organoids have what it takes to herald a new era in brain research. And if we better understand the development of our brain, new treatment options for disorders of the brain can presumably arise from this over the long term.”
Publication: Vira Iefremova, George Manikakis, Olivia Krefft, Ammar Jabali, Kevin Weynans, Ruven Wilkens, Fabio Marsoner, Björn Brändl, Franz-Josef Müller, Philipp Koch and Julia Ladewig: An Organoid-Based Model of Cortical Development Identifies Non-Cell-Autonomous Defects in Wnt Signaling Contributing to Miller-Dieker Syndrome; Cell Reports; DOI: 10.1016/j.celrep.2017.03.047
Dr. Julia Ladewig,
Institute of Reconstructive Neurobiology
University of Bonn
Tel. +49 (0)228/6885547
Johannes Seiler | idw - Informationsdienst Wissenschaft
If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
19.07.2019 | Physics and Astronomy
19.07.2019 | Physics and Astronomy
19.07.2019 | Earth Sciences