How astrocytes, certain cells of the nervous system, are generated was largely unknown up to now. Bochum’s researchers have now investigated what influence the cell environment, known as the extracellular matrix, has on this process.
Under suitable conditions, precursor cells in the nervous system (red) transform into other cell types, e.g. astrocytes (green). A fluorescence microscope image of a precursor cell culture is shown in which all cell nuclei are stained blue
Illustration: Dr. Michael Karus
The researchers from Bochum cultivated precursor cells of the nervous system as free-floating colonies called neurospheres. In the fluorescence microscope image, precursor cells are stained green, cell nuclei blue. In the neurosphere, there are also large amounts of a sugar residue (red), which is considered the classical marker for stem cells. Illustration: Dr. Michael Karus
They found out that the matrix protein tenascin C has to be present in order for astrocytes to multiply and distribute in a controlled fashion in the spinal cord of mice. Together with colleagues from the RWTH Aachen, the scientists from RUB Department of Cell Morphology and Molecular Neurobiology report their findings in the journal Development.
Tenascin C regulates astrocyte development
Immature astrocytes produce tenascin C and secrete it into the extracellular matrix. From there, it controls the development of the cells. To characterise the role of the protein more precisely, the Bochum team lead by Prof. Dr. Andreas Faissner, Prof. Dr. Stefan Wiese and Dr. Michael Karus analysed astrocytes that were genetically manipulated so that they did not produce tenascin C. The scientists observed that the astrocytes without the protein divided for a longer period of time, and migrated later to their destination in the spinal cord. “As a consequence of the longer cell division phase, we found an increased number of mature astrocytes” explained Karus.
Gene activity altered
Also at the molecular level, the tenascin C manipulation leaves its mark. With colleagues at the RWTH Aachen, Bochum’s researchers compared the gene activity in the spinal cord with and without tenascin C production. The absence of the protein not only affected genes that are typical of astrocytes. The scientists also documented expression level changes of genes that play a role for specific growth factors. These have an influence, for example, on the survival and division activity of different cell types.
Results also interesting for medical applications
Astrocytes take on a variety of tasks in the nervous system. They regulate the ion balance and the concentration of neurotransmitters, are part of the blood-brain barrier, and influence the activity of the nerve cells. In case of injuries to the central nervous system, or brain tumours, they form what are known as reactive astrocytes, which behave similarly to immature astrocytes. “So far, the function of tenascin C under such pathological conditions is largely unknown” said Karus. “However, if we find out more about the role of tenascin C during development, we will probably be able to better understand what affect it has, for example in spinal cord injuries.”
M. Karus, B. Denecke, C. ffrench-Constant, S. Wiese, A. Faissner (2011): The extracellular matrix molecule tenascin C modulates expression levels and territories of key patterning genes during spinal cord astrocyte specification, Development, doi: 10.1242/dev.067413
Further informationDr. Michael Karus, Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Tel.: +49/234/32-24312
Click for moreDepartment of Cell Morphology and Molecular Neurobiology
Dr. Josef König | idw
Machine learning microscope adapts lighting to improve diagnosis
20.11.2019 | Duke University
The neocortex is critical for learning and memory
20.11.2019 | Max-Planck-Institut für Hirnforschung
Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.
Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...
Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.
By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...
An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.
With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
15.11.2019 | Event News
15.11.2019 | Event News
05.11.2019 | Event News
20.11.2019 | Life Sciences
20.11.2019 | Physics and Astronomy
20.11.2019 | Health and Medicine