Neural stem cells generate new neurons throughout life in the mammalian brain. However, with advancing age the potential for regeneration in the brain dramatically declines. Scientists of the University of Zurich now identified a novel mechanism of how neural stem cells stay relatively free of aging-induced damage. A diffusion barrier regulates the sorting of damaged proteins during cell division.
Yeast are good for making wine, bread, and brewing beer. But they are also a good model for neural stem cells in the mammalian brain. It was known that with every division cellular aging factors are asymmetrically distributed between the mother and the daughter cell, allowing for rejuvenation and full life span of the daughter independent of the age of the mother cell. At least partially responsible for this is the presence of a diffusion barrier that restricts movement of molecules from one side to the other side of the cell during cell division.
Dividing neural stem cells establish a diffusion barrier. It participates in the asymmetric segregation of aging factors such as ubiquitinated, damaged proteins (red) during cell division.
Disposing of age
A group of scientists led by Sebastian Jessberger of the Brain Research Institute showed now that also the stem cells of the adult mouse brain asymmetrically segregate aging factors between the mother and the daughter cells.
Responsible for this is a diffusion barrier in the endoplasmic reticulum (a channel system within the cell that is for example important for protein synthesis and transport). The barrier prevents retention of damaged proteins in the stem cell daughter cell keeping the stem cells relatively clean. «Neural stem cell divisions appear to be much more asymmetric than we had previously anticipated,» states Darcie Moore, postdoc in the group of Sebastian Jessberger and lead author of the study.
In addition, the authors of the new study published in «Science» found that the strength of the barrier weakens with advancing age. This leads to reduced asymmetry of damaged protein segregation with increasing age of the stem cell. This could be one of the mechanisms responsible for the reduced regeneration capacity in the aged brain as stem cells that retain larger amounts of damaged proteins require longer for the next cell division.
Sebastian Jessberger says: «This is an exciting new mechanism involved in stem cell division and aging. But as of now we are only just beginning to understand the molecular constituents and the true meaning of the barrier for stem cell division in the brain.» One key question to be answered is whether the barrier is established in all somatic stem cells of the body. The answer to this question may open new routes to target age-dependent alterations of stem cell activity in human disease.
Other researchers involved were Gregor-Alexander Pilz, Brain Research Institute, UZH, Marcos Arauzo-Bravo, Biodonostia Health Research Institute, San Sebastian and Yves Barral, Institute of Biochemistry, ETH Zurich. The work was supported by the Swiss National Science Foundation, the Zurich Neuroscience Center of UZH and ETH Zurich, the EMBO Young Investigator Program, the ETH Fellow program, the ERC, and the Human Frontier Science Program.
Darcie L. Moore, Gregor-Alexander Pilz, Marcos J. Araúzo-Bravo, Yves Barral, Sebastian Jessberger. A mechanism for the segregation of age in mammalian neural stem cells. Science, 17 September 2015. doi:10.1126/science.aac9868
Evelyne Brönnimann | Universität Zürich
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences